.I 1
.T
Preliminary Report-International Algebraic Language
.A
Perlis, A. J.
Samelson,K.
.I 2
.T
Extraction of Roots by Repeated Subtractions for Digital Computers
.A
Sugai, I.
.I 3
.T
Techniques Department on Matrix Program Schemes
.A
Friedman, M. D.
.I 4
.T
Glossary of Computer Engineering and Programming Terminology
.I 5
.T
Two Square-Root Approximations
.A
Wadey, W. G.
.I 6
.T
The Use of Computers in Inspection Procedures
.A
Muller, M. E.
.I 7
.T
Glossary of Computer Engineering and Programming Terminology
.I 8
.T
On The Equivalence and Transformation of Program Schemes
.A
Friedman, M. D.
.I 9
.T
Proposal for an UNCOL
.A
Conway, M. E.
.I 10
.T
Glossary of Computer Engineering and Programming Terminology
.I 11
.T
The Problem of Programming Communication with
Changing Machines A Proposed Solution-Part 2
.A
Strong, J.
Wegstein, J.
Tritter, A.
Olsztyn, J.
Mock, O.
Steel, T.
.I 12
.T
Error Estimation in Runge-Kutta Procedures
.A
Call, D. H.
Reeves, R. F.
.I 13
.T
Glossary of Computer Engineering and Programming Terminology
.I 14
.T
The Problem of Programming Communication with
Changing Machines A Proposed Solution (Part 1)
.A
Strong, J.
Wegstein, J.
Tritter, A.
Olsztyn, J.
Mock, O.
Steel, T.
.I 15
.T
Recursive Curve Fitting Technique
.A
Giblin, J.
.I 16
.T
Secant Modification of Newton's Method
.A
Jeeves, T. A.
.I 17
.T
On Programming of Arithmetic Operations
.A
Ershov, A. P.
.I 18
.T
Simple Automatic Coding Systems
.A
Adams, E. S.
Schlesinger, S. I.
.I 19
.T
Glossary of Computer Engineering and Programming Terminology
.I 20
.T
Accelerating Convergence of Iterative Processes
.W
A technique is discussed which, when applied
to an iterative procedure for the solution of
an equation, accelerates the rate of convergence if
the iteration converges and induces convergence if
the iteration diverges.  An illustrative example is given.
.A
Wegstein, J. H.
.I 21
.T
Algebraic Formulation of Flow Diagrams
.A
Voorhees, E. A.
.I 22
.T
Unusual Applications Department--Automatic
Implementation of Computer Logic
.A
Morris, E. F.
Wohr, T. E.
.I 23
.T
Binary and Truth-Function Operations on
a Decimal Computer with an Extract Command
.A
Kautz, W. H.
.I 24
.T
An Improved Decimal Redundancy Check
.A
Sisson, R. L.
.I 25
.T
General Purpose Programming Systems
.A
Holt, A. W.
.I 26
.T
A Subroutine Method for Calculating Logarithms
.A
Bemer, R. W.
.I 27
.T
Note On Empirical Bounds For Generating Bessel Functions
.A
Randels, J. B.
Reeves, R. F.
.I 28
.T
Request for Methods or Programs
.A
Corley, H. P. T.
.I 29
.T
Need for an Algorithm
.A
Selden, W.
.I 30
.T
Algorithm for Analyzing Logical Statements
to Produce a Truth Function Table
.A
Wolpe, H.
.I 31
.T
IBM 704 Code-Nundrums
.A
Grumette, M.
.I 32
.T
Variable-Width Tables with Binary-Search Facility
.A
Halpern, M.
.I 33
.T
A Programmed Binary Counter For The IBM Type 650 Calculator
.A
Kenny, B. C.
Hunter, J. A.
.I 34
.T
Tables for Automatic Computation
.A
Wilf, H. S.
.I 35
.T
A Machine Method for Square-Root Computation
.A
Bemer, R. W.
.I 36
.T
A Queue Network Simulator for the IBM 650 and Burroughs 220
.A
Conway, R. W.
Johnson, B. M.
Maxwell, W. L.
.I 37
.T
Impact of Computer Developments
.A
Humphrey, S. M.
.I 38
.T
A Proposed Interpretation in ALGOL
.A
Irons, E. T.
Acton, F. S.
.I 39
.T
The Secant Method for Simultaneous Nonlinear Equations
.W
A procedure for the simultaneous solution
of a system of not-necessarily-linear equations,
a generalization of the secant method for a
single function of one variable, is given.
.A
Wolfe, P.
.I 40
.T
Fingers or Fists? (The Choice of Decimal or Binary Representation)
.W
The binary number system offers many advantages
over a decimal representation for a high-performance,
general-purpose computer.  The greater simplicity of
a binary arithmetic unit and the greater compactness
of binary numbers both contribute directly to arithmetic
speed.  Less obvious and perhaps more important
is the way binary addressing and instruction formats can
increase the overall performance.  Binary addresses
are also essential to certain powerful operations which
are not practical with decimal instruction formats.
 On the other hand, decimal numbers are essential for
communicating between man and the computer.  In
applications requiring the processing of a large volume
of inherently decimal input and output data,
the time for decimal-binary conversion needed by a purely
binary computer may be significant.  A slower
decimal adder may take less time than a fast binary adder
doing an addition and two conversions.  A careful
review of the significance of decimal and binary addressing
and both binary and decimal data arithmetic,
supplemented by efficient conversion instructions.
.A
Buchholz, W.
.I 41
.T
Some Notes on Computer Research in Eastern Europe
.A
Nadler, M.
.I 42
.T
A New Method of Computation of Square Roots Without Using Division
.A
Sarafyan, D.
.I 43
.T
A Technique for Handling Macro Instructions
.A
Greenwald, I. D.
.I 44
.T
RUNCIBLE-Algebraic Translation on a Limited Computer
.A
Knuth, D. E.
.I 45
.T
Flow Outlining-A Substitute for Flow Charting
.A
Gant, W. T.
.I 46
.T
Multiprogramming STRETCH: Feasibility Considerations
.W
The tendency towards increased parallelism in
computers is noted.  Exploitation of this parallelism
presents a number of new problems in machine design
and in programming systems.  Minimum requirements
for successful concurrent execution of several independent
problem programs are discussed.  These requirements
are met in the STRETCH system by a carefully balanced
combination of built-in and programmed logic.
Techniques are described which place the burden of the
programmed logic on system programs (supervisory
program and compiler) rather than on problem programs.
.A
Codd, E. F.
Lowry, E. S.
McDonough, E.
Scalzi, C. A.
.I 47
.T
Russian Visit to U.S. Computers
.A
Zaitzeff, E. M.
Astrahan, M. M.
.I 48
.T
Shift-Register Code for Indexing Applications
.W
In this communication the use of a shift-register
code with n = 10 is described for calling
64 wireless telemetering stations in a fixed cyclical order.
 A high degree of redundancy is used, permitting
a single-error correcting code ("minimum-distance-three"
code) with 64 10-bit code words to be employed
as the station identification code.  Embedding this in
the shift-register code with period 1023 permits
the code to be employed without punctuation, each of
the telemetering station receivers simply putting
received ones and zeros into a shift register.  Each
time the given code combination arises identifying
the particular station (barring for tuitous error combinations
of very low probability) it has been called.
 The communication describes the properties and application
of the code in some detail and the finding
of the particular example to be employed on URAL, the
Soviet-built drum computer donated to the Indian
Statistical Institute by the United Nations
Technical Aid Administration (UNTAA).
.A
Nadler, M.
Sengupta, A.
.I 49
.T
Scientific and Business Applications (Oracle Curve Plotter)
.A
Fike, C. T.
.I 50
.T
Statistical Programs for the IBM 650-Part II
.A
Hamblen, J. W.
.I 51
.T
On the Construction of Micro-Flowcharts
.A
Gorn, S.
Ingerman, P. Z.
Crozier, J. B.
.I 52
.T
An Efficient Method for Generating Uniformly Distributed
Points on the Surface on an n-Dimensional
Sphere (Corrigendum)
.A
Cook, J. M.
.I 53
.T
Recommendations of the SHARE ALGOL Committee
.I 54
.T
SALE, a Simple Algebraic Language for Engineers
.A
Brittenham, W. R.
Clark, K.
Kuss, G.
Thompson, H.
Smith, A. O.
.I 55
.T
An Algebraic Translator
.A
Kaner, H.
.I 56
.T
Proposed Standard Flow Chart Symbols
.I 57
.T
J.E.I.D.A. and Its Computer Center
.I 58
.T
LEM-1, Small Size General Purpose Digital
Computer Using Magnetic (Ferrite) Elements
.W
The paper examines some of the questions of
development and construction of a general purpose
digital computer using contactless magnetic (ferrite)
and capacitive "DEZU" (long duration capacitive
memory) elements, developed at the Laboratory of Electrical
Modeling VINITYI AN SSSR, under the supervision
of Professor L.I. Gutenmacher.
.A
Machmudov, U. A.
.I 59
.T
Survey of Progress and Trend of Development
and Use of Automatic Data Processing in Business
and Management control Systems of the Federal
Government, as of December 1957-III
.I 60
.T
The Alpha Vector Transformation of a System of Linear Constraints
.A
Wersan, S. J.
.I 61
.T
IBM 709 Tape Matrix Compiler
.A
Hornick, S. D.
.I 62
.T
Multi-Dimensional Least-Squares Polynomial Curve Fitting
.A
Lesh, F. H.
.I 63
.T
Octal Diagrams of Binary Conception and
Their Applicability to Computer Design Logic
.W
This paper dates back the genesis of binary
conception circa 5000 years ago, and octal diagrams
about 4800 years ago, as derived by the Chinese ancients.
 It analyzes the applicability of binary trinities
of the octal diagrams to modern electronic-digital-computer design logic.
.A
Li, S. T.
.I 64
.T
Remarks on ALGOL and Symbol Manipulation
.A
Green, J.
.I 65
.T
ALGOL Sub-Committee Report - Extensions
.A
Dijkstra, E. W.
Heise, W.
Perlis, J. A.
Samelson, K.
.I 66
.T
A Proposal for a Generalized Card Code for 256 Characters
.A
Bemer, R. W.
.I 67
.T
Central-European Computers
.A
Blachman, N. M.
.I 68
.T
The Role of the University in Computers,
Data Processing and Related Fields
.W
A study was made of university programs in
the United States in the fields of computers, data
processing, operations research, and other closely related
fields.  University policies, organization,
administration, faculties, students, researches, curricula,
equipment, and financing were investigated.
 An integrated university program is recommended reflecting
the conviction that many present activities
related to computers will develop into disciplines and
as such are the legitimate province of the university
scholar.  Details on a recommended Graduate
School of "Computer Sciences" are given.
.A
Fein, L.
.I 69
.T
Statistical Programs for the IBM 650-Part I
.W
A collection is given of brief descriptions
of statistical programs now in use in university
computing centers which have IBM 650's.
.A
Hamblen, J. W.
.I 70
.T
Construction of a Set of Test Matrices
.W
This paper develops the equations and properties
of a set of test matrices which are useful
in the determination of the accuracy of routines for
finding the inverse, determinant and/or eigenvalues
of a matrix.
.A
Aegerter, M. J.
.I 71
.T
Proposal for a Feasible Programming System
.W
This paper proposes designing a programming
facility (itself involving a digital computer and
a program) which will assist the preparation of large-scale
real-time programs.  This facility is to
be capable of preparing programs for any of a variety
of machines having characteristics similar to those
of the facility's computer.  One of the basic assumptions
is that there will be enough random-access
storage available to avoid the necessity for segmenting
a constructed program in any fashion other than
a trivial one.  While this assumption is somewhat unrealistic,
it is intended to provide an opportunity
to concentrate on the other aspects of program construction.
 The programming system should stress the
discovery in source program statements of as many errors
as possible, before attempting to construct
an object program.  Among the computer characteristics
which are advocated are a program interrupt scheme,
a large set of characters, and indirect addressing.
.A
Bagley, P. R.
.I 72
.T
An Educational Program in Computing
.A
Hollingsworth, J.
.I 73
.T
A Real Time Data Assimilator
.A
Gschwind, H. W.
.I 74
.T
A High-Speed Sorting Procedure
.A
Shell, D. L.
.I 75
.T
Parameter Estimation for Simple Nonlinear Models
.A
Chow, W. M.
.I 76
.T
Binary Conversion, With Fixed Decimal Precision, Of a Decimal Fraction
.A
Taranto, D.
.I 77
.T
On GAT and the Construction of Translators
.A
Arden, B.
Graham, R.
.I 78
.T
Remarks on the Practical Solution of Characteristic Value Problems
.W
This paper is concerned with the practical
solution of characteristic value problem for an
ordinary differential equation.  It is at once apparent
that sequential computers, be they digital or
analog, solve initial value problems, rather than boundary
value problems, and some mathematical process
must be found to compensate for the machine's inadequacy.
 (Compensating for machine imperfection is,
of course, the normal activity of the numerical analyst.)
 A number of other papers have applied particular
devices to particular problems.  The purpose of this
note is to establish a mathematical framework or
model for these practical procedures and thus assist in
the use and extension of the ideas in other particular
problems.
.A
Wouk, A.
.I 79
.T
Programming for a Machine With an Extended
Address Calculational Mechanism
.A
Schecher, H.
.I 80
.T
A Technique for Computing Critical Rotational
Speeds of Flexible Shafts on an Automatic Computer
.A
Schwartz, B. L.
.I 81
.T
NORC High-Speed Printer
.A
Gleissner, G. H.
.I 82
.T
Handling Identifiers as Internal Symbols in Language Processors
.W
Substitution of computer-oriented symbols for
programmer-oriented symbols in language processors
is examined and a feasible method for doing so is presented.
.A
Williams, F. A.
.I 83
.T
A Visit to Computation Centers in the Soviet Union
.A
Carr III, J. W.
.I 84
.T
Survey of Progress and Trend of Development
and Use of Automatic Data Processing in Business
and Management Control Systems of the Federal Government,
as of December 1957-II (Part 2 see CA590406)
.I 85
.T
Error Analysis in Floating Point Arithmetic
.A
Carr III, J. W.
.I 86
.T
Survey of Progress and Trend of Development
and Use of Automatic Data Processing in Business
and Management Control Systems of the Federal Government, as of December 1957
.A
Controller General of the United States to the Congress of the United States
.I 87
.T
A Note on a Method for Generating Points
Uniformly on N-Dimensional Spheres
.A
Muller, M. E.
.I 88
.T
An Efficient Method for Generating Uniformly Distributed
Points on the Surface of an n-Dimensional
Sphere
.A
Hicks, J. S.
Wheeling, R. F.
.I 89
.T
A Routine to Find the Solution of Simultaneous
Linear Equations with Polynomial Coefficients
.A
Larson, E. H.
Marshall, D. P.
.I 90
.T
Binary Arithmetic for Discretely Variable
Word Length in a Serial Computer
.A
Ercoli, P.
Vacca, R.
.I 91
.T
A Mathematical Procedure for Machine Division
.A
Gilman, R. E.
.I 92
.T
A Checklist of Intelligence for Programming Systems
.W
A remarkable variation exists in the degree
of sophistication of various programming systems.
 A particular manifestation is the jungle of assorted
devices for reproducing limited human decision
procedures.  An attempt is made here to begin a systematic
classification of the various devices for
educating the computer to take over the decision-making
functions of one or many human operators, both
those that have been demonstrated feasible to date and
those that are highly desirable for the future.
.A
Bemer, R. W.
.I 93
.T
From Formulas to Computer Oriented Language
.W
A technique is shown for enabling a computer
to translate simple algebraic formulas into a
three address computer code.
.A
Wegstein, J. H.
.I 94
.T
An Iterative Method for Fitting the Logistic Curve
.W
An iterative method is given for finding a
logistic curve of best least squares fit to a set
of two-dimensional points.
.A
Howell, J.R.
.I 95
.T
Elimination of Special Functions from Differential Equations
.W
A set of ordinary differential equations which
contains mathematical functions requiring the
use of subroutines for numerical solution by electronic
computer, tabular data for numerical solution
by hand calculation or function generators when analog
methods are applied can sometimes be expanded
to an equivalent set of equations which do not contain
the functions.  This is practical if these functions
satisfy sufficiently simple differential equations.
Thus among those functions which can be eliminated
by this procedure are the trigonometric, inverse trigonometric,
exponential, and many other transcendental
functions.
.A
Powers, J. E.
.I 96
.T
On Computing Radiation Integrals
.W
The relative merit and cost of four ways of
evaluating typical radiation integrals containing
spherical Bessel functions are investigated.  These methods
are desk machine evaluation of a finite series,
integration of the appropriate differential equation
by a Reeves Electronic Analog Computer and by a
Litton 40 IBM 704 computer.  Results are generally applicable
to equations separated from a Helmholtz
or wave equation.
.A
Hansen, R. C.
Bailin, L. L.
Rutishauser, R. W.
.I 97
.T
Signal Corps Research and Development on
Automatic Programming of Digital Computers
.A
Luebbert, Capt. W. F.
Collom Jr., Capt. P. W.
.I 98
.T
The Arithmetic Translator-Compiler of
the IBM FORTRAN Automatic Coding System
.A
Sheridan, P. B.
.I 99
.T
Possible Modifications to the International Algebraic Language
.A
Green, J.
.I 100
.T
Recursive Subscripting Compilers and List-Types Memories
.A
Carr III, J. W.
.I 101
.T
Nuclear Reactor Codes
.A
Nather, V.
Sangren, W.
.I 102
.T
A Comparison of 650 Programming Methods
.A
Curtz, T. B.
Riordan, J. F.
Spohn,M.
.I 103
.T
COPE (Console Operator Proficiency Examination)*
.W
Each year electronic computers become more
sophisticated, and the programs they must process
become more complex.  Because of this,dependence of
those in computing on the skill and experience of
operators is increasing.  At the same time, selection
and training of qualified operators grows more
difficult.  To meet the need for a quick, accurate, uniform
operator test and training aid, the authors
have developed COPE (Console Operator Proficiency Examination),
outlined below.  While this examination
is programmed specifically for the IBM 705 Model II with
two Tape Record Coordinators, similar programs
could be developed for other computers.
.A
Farbman, D.
Ketover, R.
.I 104
.T
Digital Simulation of Discrete Flow Systems*
.W
The discrete flow systems discussed are characterized
by the movement of randomly arriving
items along interacting channels.  Programing a digital
computer to simulate such systems utilizes some
techniques not common in other approaches to physical
problems.  The principal portion of the paper is
a discussion of two simulation studies that illustrate
some of the programming problems involved. One
is of an extensive package-handling plant, with the
objective being optimization of parameters such as
storage capacities and processing rates.  In the other,
air traffic flow and control procedures are simulated
to compare the effects of alternative control decisions.
.A
Moore, C. J.
Lewis, T. S.
.I 105
.T
Two Methods for Word Inversion on the IBM 709
.A
Price, R. A.
Jardins, P. D.
.I 106
.T
A Method for Overlapping and Erasure of Lists
.W
An important property of the Newell-Shaw-Simon
scheme for computer storage of lists is that
data having multiple occurrences need not be stored
at more than one place in the computer.  That is,
lists may be "overlapped."  Unfortunately, overlapping
poses a problem for subsequent erasure.  Given
a list that is no longer needed, it is desired to erase
just those parts that do not overlap other lists.
 In LISP, McCarthy employs an elegant but inefficient solution
to the problem.  The present paper describes
a general method which enables efficient erasure.  The
method employs interspersed reference counts to
describe the extent of the overlapping.
.A
Collins, G. E.
.I 107
.T
Multiple Precision Arithmetic
.A
Pope, D. A.
Stein, M. L.
.I 108
.T
Programmed Error Correction in Project Mercury
.A
Dimsdale, B.
Weinberg, G. M.
.I 109
.T
A Note on Approximating e^x
.A
Lubkin, S.
.I 110
.T
Fibonaccian Searching
.A
Ferguson, D. E.
.I 111
.T
On Programming the Numerical Solution of Polynomial Equations
.W
Numerical techniques are presented for computing
the roots of polynomial equations.  By applying
the recommended scaling and inversion rules, the basic
Bairstow and Newton-Raphson iterative techniques
can be applied with great reliability.  Both a high degree
of accuracy and rapid convergence are realized.
 Numerical examples are shown to illustrate the pitfalls
and to show how these are circumvented by application
of the recommended procedures.
.A
Ellenberger, K. W.
.I 112
.T
Numerical Solution of the Polynomial Equation (Algorithm 30)
.A
Ellenberger, K. W.
.I 113
.T
Survey of Coded Character Representation
.A
Bemer, R. W.
.I 114
.T
Survey of Punched Card Codes
.A
Smith, H. J.
Williams, F. A.
.I 115
.T
Optimizers: Their Structure
.A
Wheeling, R. F.
.I 116
.T
The Sumador Chino
.W
On a recent motor trip through Mexico, the writer
came across on adding device which was referred
to as a sumador chino (Chinese adder).  A survey of the more
available literature on the history of mathematics
and on instruments of calculation has uncovered no reference
to such a device.  The purpose of this communication
is to enlist the help of other members in bringing to
light whatever may be known concerning the evolution
and present status of the sumador chino.
.A
Rogers, J. L.
.I 117
.T
An Estimation of the Relative Efficiency of Two Internal Sorting Methods
.A
Nagler, H.
.I 118
.T
Character Scanning on the IBM 7070
.A
Speckhard, A. E.
.I 119
.T
Note on Eigenvalue Computation
.A
Andrus, J. F.
.I 120
.T
A Simple Technique for Coding Differential Equations
.A
Sefton, P.
Vaillancourt, R.
.I 121
.T
Over-all Computation Control and Labelling
.A
Holt, A.
.I 122
.T
Least Squares Fitting of a Great Circle Through Points on a Sphere
.A
DeWitte, L.
.I 123
.T
Compilation for Two Computers with NELIAC
.W
NELIAC, a compiler based on ALGOL, was developed
at the U.S. Navy Electronics Laboratory, San
Diego,California, as a"boot-strap" compiler for the Remington
Rand Univac COUNTESS computer. This compiler
was used to generate a version of itself which, running
as a COUNTESS program, generated machine code
for the Control Data Corporation CDC-1604.  All three
versions of NELIAC accepted essentially identical
input language.
.A
Masterson Jr., K. S.
.I 124
.T
An Algorithm for the Assignment Problem
.W
The assignment problem is formulated and briefly
discussed.  An efficient algorithm for its
solution is presented in ALGOL code.  An empirical relation
between solution time and the size of the
problem is given, based on extensive experiments
carried out on a digital computer.
.A
Silver, R.
.I 125
.T
Polynomial Transformer (Algorithm 29)
.A
Mackinney, J. G.
.I 126
.T
Least Squares Fit By Orthogonal polynomials (Algorithm 28)
.A
Mackinney, J. G.
.I 127
.T
ASSIGNMENT (Algorithm 27)
.A
Silver, R.
.I 128
.T
ROOTFINDER III (Algorithm 26)
.A
Herroit, J. G.
.I 129
.T
ROOTFINDER II (Algorithm 15)
.A
Forsythe, G. E.
Herriot, J. G.
.I 130
.T
Real Zeros of an Arbitrary Function (Algorithm 25)
.A
Leavenworth, B.
.I 131
.T
Solution of Tri-Diagonal Linear Equations (Algorithm 24)
.A
Leavenworth, B.
.I 132
.T
Math Sort (Algorithm 23)
.A
Feurzeig, W.
.I 133
.T
Riccati-Bessel Functions of First And Second Kind (Algorithm 22)
.A
Oser, H.
.I 134
.T
Bessel Function for a Set of Integer Orders(Algorithm 21)
.A
Borsch-Supan, W.
.I 135
.T
Digital Computers in Universities-IV
.A
Reeves, R. F.
.I 136
.T
A Note on the Calculation of Interest
.A
Ingerman, P. Z.
.I 137
.T
Evaluating Numbers Expressed as Strings of English Words
.A
Swift, C. J.
.I 138
.T
Some Thoughts on Reconciling Various
Character Set Proposals (Corrigenda)
.A
Voorhees, E. A.
.I 139
.T
Binomial Coefficients (Algorithm 19)
.A
Kenyon, R. R.
.I 140
.T
Crout with Pivoting (Algorithm 16)
.A
Forsythe, G. E.
.I 141
.T
Some Thoughts on Parallel Processing
.A
Yarbrough, L. D.
.I 142
.T
Comments on a Technique for Counting Ones
.A
Sherman, P. M.
.I 143
.T
A List of Computer Systems Programs for
the IBM 650, DATATRON 205, and UNIVAC SS-80
.A
Romberg, A.
.I 144
.T
Do It by the Numbers-Digital Shorthand
.W
Present communications systems transmit single
characters in groups of coded pulses between
simple terminal equipments.  Since English words form only
a sparse set of all possible alphabetic combinations,
present methods are inefficient when computer systems
are substituted for these terminals.  Using numeric
representations of entire words or common phrases (rather
than character-by-character representations)
requires approximately one-third of present transmission
time.  This saving is reflected in overall costs.
 Other benefits accrue in code and language translation
schemes. Provision is made for transmission of
purely numeric and/or binary streams, and for single
character-transmission of non-dictionary words such
as the names of people or places.
.A
Bemer, R. W.
.I 145
.T
Automatic Graders for Programming Classes
.A
Hollingsworth, J.
.I 146
.T
The Use of Computers in Engineering Classroom Instruction
.W
On April 29-30, the Computer Committee of the
College of Engineering, University of Michigan,
which acts as a steering committee for The Ford Foundation
Project on the Use of Computers in Engineering
Education, held a special conference to discuss certain
timely topics pertinent to the Ford Project.
 This report contains a condensed transcription of
the key ideas offered by the conference attendees
on selected topics.
.A
Katz, D. L.
.I 147
.T
Report on a Conference of University Computing Center Directors
.I 148
.T
Digital Computers in Universities-III
.A
Reeves, R. F.
.I 149
.T
A Decision Rule for Improved Efficiency in Solving
Linear Programming Problems with the Simplex
Algorithm
.A
Dickson, J. C.
Frederick, F. P.
.I 150
.T
Rational Interpolation by Continued Fractions (Algorithm 18)
.A
Floyd, R. W.
.I 151
.T
TRDIAG (Algorithm 17)
.A
Sprague III, C. D.
.I 152
.T
CROUT With Pivoting (Algorithm 16)
.A
Forsythe, G. E.
.I 153
.T
Comments from a FORTRAN User
.A
Blatt, J. M.
.I 154
.T
Rapidly Convergent Expressions for Evaluating e^x
.A
Berin, A.
.I 155
.T
Trie Memory
.A
Fredkin, E.
.I 156
.T
An Introductory Problem in Symbol Manipulation for the Student
.A
Rosin, R. F.
.I 157
.T
Digital Computers in Universities -II
.A
Reeves, R. F.
.I 158
.T
ROOTFINDER II (Algorithm 15)
.A
Thacher Jr., H. C.
.I 159
.T
ROOTFINDER (Algorithm 2)
.A
Thacher Jr., H. C.
.I 160
.T
ROOTFINDER II (Algorithm 15)
.A
Thacher Jr., H. C.
.I 161
.T
Abbreviating Words Systematically (Corrigendum)
.A
Barrett, J. A.
Grems, M.
.I 162
.T
A Variant Technique for Counting Ones
.A
Frieden, H.
.I 163
.T
Counting Ones on the IBM 7090
.A
Kutler, S. S.
.I 164
.T
A Short Study of Notation Efficiency
.A
Smith Jr., H. J.
.I 165
.T
NELIAC-A Dialect of ALGOL
.A
Huskey, H. D.
Halstead, M. H.
.I 166
.T
Programming Compatibility in a Family
of Closely Related Digital Computers
.A
Luebbert, W. F.
.I 167
.T
Combining ALGOL Statement Analysis with Validity Checking
.A
McIsaac, P.
.I 168
.T
Multiprogram Scheduling Parts 3 and 4 Scheduling
Algorithm and External Constraints
.A
Codd, E. F.
.I 169
.T
The Multilingual Terminology Project
.A
Holmstrom, J. E.
.I 170
.T
Some Thoughts on Reconciling Various Character Set Proposals
.A
Voorhees, E. A.
.I 171
.T
Digital Computers in Universities (Part I)
.A
Reeves, R. F.
.I 172
.T
Complex Exponential Integral (Algorithm 13)
.A
Beam, A.
.I 173
.T
ATLAS a new concept in large computer design
.I 174
.T
Interval Estimation of the Time in One State
to Total Time Ratio in a DoubleExponential Process
.A
Neal, W. R.
.I 175
.T
The Solution of Simultaneous Ordinary Differential
Equations Using a General Purpose Digital
Computer
.A
Anderson, W. H.
.I 176
.T
Symbol Manipulation by Threaded Lists (Corrigendum)
.A
Perlis, A. J.
Thornton, C.
.I 177
.T
Solution of Polynomial Equation by Bairstow
Hitchcock Method, A. A. Grau Communications ACM,
February, 1960 (Algorithm)
.A
Thacher Jr., H. C.
.I 178
.T
ROOTFINDER (Algorithm)
.A
Thacher Jr., H. C.
.I 179
.T
Evaluation of the Legendre Polynomial Pn(X) by Recursion (Algorithm)
.A
Galler, G. M.
.I 180
.T
Evaluation of the Laguerre Polynomial Ln(X) by Recursion (Algorithm)
.A
Galler, G. M.
.I 181
.T
Evaluation of the Hermite Polynomial Hn(X) by Recursion (Algorithm)
.A
Galler, G. M.
.I 182
.T
Evaluation of the Chebyshev Polynomial Tn(X) by Recursion (Algorithm)
.A
Galler, G. M.
.I 183
.T
Conversion Between Floating Point Representations
.A
Perry, C.
.I 184
.T
A Short Method for Measuring Error in a Least-Squares Power Series
.A
Robinson, S. M.
Struble, G. W.
.I 185
.T
Multiprogram Scheduling Parts 1 and 2.  Introduction and Theory*
.W
In order to exploit fully a fast computer which
possesses simultaneous processing abilities,
it should to a large extent schedule its own workload.
 The scheduling routine must be capable of extremely
rapid execution if it is not to prove self-defeating.
 The construction of a schedule entails determining
which programs are to be run concurrently and which sequentially
with respect to each other.  A concise
scheduling algorithm is described which tends to minimize
the time for executing the entire pending workload
(or any subset of it), subject to external constraints
such as precedence, urgency, etc.  The algorithm
is applicable to a wide class of machines.
.A
Codd, E. F.
.I 186
.T
An Algorithm Defining ALGOL Assignment Statements (Addendum)
.A
Floyd, R. W.
.I 187
.T
Compiling Connectives
.A
Swift, C. J.
.I 188
.T
The Department of Computer Mathematics at Moscow State University
.A
Berezin, I. S.
.I 189
.T
The Future of Automatic Digital Computers
.A
Booth, A. D.
.I 190
.T
Bendix G-20 System
.I 191
.T
Abbreviating Words Systematically
.A
Barrett, J. A.
Grems, M.
.I 192
.T
A Technique for Counting Ones in a Binary Computer
.A
Wegner, P.
.I 193
.T
A Start at Automatic Storage Assignment
.A
Patrick, R. L.
.I 194
.T
Divisionless Computation of Square Roots Through Continued Squaring
.A
Sarafyan, D.
.I 195
.T
What is a Code?
.A
Patterson, G. W.
.I 196
.T
Report on the Algorithmic Language ALGOL 60
.A
Naur, P.
Backus, J.
.I 197
.T
An Imaginary Number System
.A
Knuth, D. E.
.I 198
.T
A High-Speed Multiplication Process for Digital Computers
.A
Gurzi, F.
.I 199
.T
Euclidian Algorithm (Algorithm 7)
.A
Claussen, R.
.I 200
.T
Bessel Function I, Asymptotic Expansion (Algorithm 6)
.A
Clarke, D. S.
.I 201
.T
Bessel Funtion I, Series Expansion (Algorithm 5)
.A
Clarke, D. S.
.I 202
.T
A Control System For Logical Block Diagnosis With Data Loading
.W
This paper describes a section of an integrated
diagnostic monitor system which facilitates
the checking of sections of instructions or subroutines
anywhere in the object program.  A new method
of specifying all diagnostic operations in a format similar
to a computer program makes the system convenient
to use and relatively simple to understand.  The paper
also describes a number of other novel diagnostic
features which can be included in the system.
.A
Senko, M. E.
.I 203
.T
Decoding Combinations of the First n Integers Taken k at a Time
.A
Brown, R. M.
.I 204
.T
Proving Theorems by Pattern Recognition I
.A
Wang, H.
.I 205
.T
Macro Instruction Extensions of Compiler Languages
.W
Macroinstruction compilers constructed from
a small set of functions can be made extremely
powerful.  In particular, conditional assembly, nested
definitions, and parenthetical notation serve
to make a compiler capable of accepting very
general extensions to its ground language.
.A
McIlroy, M. D.
.I 206
.T
Symbol Manipulation in XTRAN
.A
Green, J.
.I 207
.T
Syntactic and Semantic Augments to ALGOL
.A
Smith, J. W.
.I 208
.T
An Introduction to Information Processing Language V
.A
Newell, A.
Tonge, F. M.
.I 209
.T
Symbol Manipulation by Threaded Lists
.A
Perlis, A. J.
Thornton, C.
.I 210
.T
Recursive Functions of Symbolic Expressions
and Their Computation by Machine, Part I
.A
McCarthy, J.
.I 211
.T
Share Standard Flow Chart Symbols
.A
Grems, M.
.I 212
.T
Bisection Routine (Algorithm 4)
.A
Gorn,S.
.I 213
.T
Numerical Inversion of Laplace Transforms
.A
Schmittroth, L. A.
.I 214
.T
An Algorithm Defining ALGOL Assignment Statements
.A
Floyd, R. W.
.I 215
.T
The Execute Operations-A Fourth Mode of Instruction Sequencing
.A
Brooks, F. P.
.I 216
.T
A Note on the Use of the Abacus in Number Conversion
.A
Kanner, H.
.I 217
.T
Soviet Computer Technology-1959
.I 218
.T
Computer Preparation of a Poetry Concordance
.A
Painter, J. A.
.I 219
.T
Marriage-with Problems
.A
Shuchter, J. P.
.I 220
.T
A New Method of Computation of Square Roots Without Using Division
.A
Traub, J. F.
.I 221
.T
The Basic Side of Tape Labeling
.A
Logan, W. A.
.I 222
.T
Coding Isomorphisms
.W
The coding of external symbols into symbols
internal to a compute can sometimes be carried
out in such a way that relevant informational properties
are preserved, but in a form much more easily
dealt with.  A case in point is presented.
.A
Lynch, W. C.
.I 223
.T
Selfcipher: Programming
.A
Pelta, H. N.
.I 224
.T
Sequential Formula Translation
.W
The syntax of an algorithmic language such
as ALGOL is conveniently described as a sequence
of states indicated by an element called cellar.  Transitions
are controlled by admissible state-symbol
pairs which may be represented by a transition matrix.
This description of syntax furnishes at the same
time an extremely simple rule for translating into machine
programs statements in the algorithmic language.
 Sequential treatment, however, is not feasible in the case
of certain optimizing processes such as recursive
address calculation.
.A
Samelson, K.
Bauer, F. L.
.I 225
.T
A Techniquefor Handling Macro Instructions (Corrigendum)
.A
Greenwald, I. D.
.I 226
.T
Solution of Polynomial Equation by
Bairstow-Hitchcock Method (Algorithm 3)
.A
Grau, A. A.
.I 227
.T
ROOTFINDER (Algorithm 2)
.A
Wegstein, J.
.I 228
.T
QUADI (Algorithm 1)
.A
Herbold, R. J.
.I 229
.T
A Terminology Proposal
.A
Gruenberger, F.
.I 230
.T
A Proposal for Character Code Compatibility
.A
Bemer, R. W.
.I 231
.T
A Proposal for a Set of Publication Standards for Use by the ACM
.A
Kent, E. R.
.I 232
.T
A High-Speed Sorting Procedure
.A
Frank, R. M.
Lazarus, R. B.
.I 233
.T
Abstracts-Additional Nuclear Reactor Codes
.A
Nather, V.
Sangren, W.
.I 234
.T
A SAP-Like Assembly Program for the IBM 650
.A
Speckhard, A. E.
.I 235
.T
Two Think Pieces
.A
Bagley, P. R.
.I 236
.T
Soviet Cybernetics and Computer
.W
This article records observations on Soviet
research and technology in cybernetics and computer
science, made by the author during a visit to the Soviet
Union as a delegate to the IFAC Congress on
Automatic Control held in Moscow in the summer of 1960.
.A
Feigenbaum, E. A.
.I 237
.T
Computer Production of Peek-A-Boo Sheets
.A
Robbins, D.
.I 238
.T
Simulation and Analysis of Biochemical Systems
.A
Garfinkel, D.
Rutledge, J. D.
Higgins, J. J.
.I 239
.T
Inefficiency of the Use of Boolean Functions
for Information Retrieval Systems
.A
Verhoeff, J.
Goffman, W.
Belzer, J.
.I 240
.T
Processing Magnetic Tape Files with Variable Blocks
.A
Graham, J. W.
Sprott, D. A.
.I 241
.T
Machine Calculation of Moments of a Probability Distribution
.W
A method is presented for the calculation on a
machine of the moments of a probability distribution,
necessitating little more than n additions and n references
to memory for each moment, instead of the
minimum of n multiplication, 2n additions, and 2n references
to memory required by the most straightforward
method (where n is the number of entries in the probability
distribution).  The method is directly applicable
when a tabulated distribution exists, as when it has
been computed by repeated convolution; but in this
case it conserves both time and accuracy.
.A
Lechner, J. A.
.I 242
.T
Notes on Geometric Weighted Check Digit Verification
.W
This note describes a method for utilizing
geometric weight modulus 11 checking digits on a
computer which does not have either multiplication or
division.  In addition some attempt has been made
to show some limitations of this system.
.A
Wilson, J. G.
.I 243
.T
N-Dimensional Codes for Detecting and Correcting Multiple Errors
.W
The paper introduces a new family of codes
for detecting and correcting multiple errors in
a binary-coded message.  The message itself is arranged
(conceptually) into a multidimensional rectangular
array.  The processes of encoding and error detection
are based upon parity evaluations along prescribed
dimensions of the array.  Effectiveness of the codes
is increased by introducing a "system check bit",
which is essentially a parity check on the other parity
bits.  Only three-dimensional codes are discussed
in this paper with parity evaluations along the horizontal,
the vertical, and one main diagonal.  However,
the family of codes is not restricted to three dimensions,
as evidenced by the discussion by Minnick
and Ashenhurst on a similar multidimensional single-bit
selection plan used for another purpose [6].
 A four-dimensional code, correcting three and detecting
four errors, has been developed; the extension
to higher-dimensional codes with greater correction power is straightforward.
.A
Rubinoff, M.
.I 244
.T
Incomplete Elliptic Integrals (Algorithm 73)
.A
Kriebel, D. C.
.I 245
.T
A Set of Associate Legendre Polynomials of the Second Kind (Algorithm 62)
.A
Herndon, J. R.
.I 246
.T
Least-Squares Fit by Orthogonal Polynomials (Algorithm 28)
.A
MacMillan, D. B.
.I 247
.T
Incomplete Elliptic Integrals (Algorithm 73)
.A
Jefferson, D. K.
.I 248
.T
What is Proprietary In Mathematical Programming?-Impressions
of a Panel Discussion
.W
A panel discussion on "What is Proprietary
in Mathematical Programming?" was sponsored by the
Special Interest Committee on Mathematical Programming
of the ACM during a Hall of Discussion/on September
7th at the 16th National ACM meeting in Los Angeles.  This
note consists solely of the impressions garnered
by the moderator of the panel and does not necessarily
represent the position of any of the panelists
or other participants in the discussion.
.A
Smith, L. W.
.I 249
.T
Specification Languages for Mechanical Languages
and Their Processors*-A Baker's Dozen
.A
Gorn, S.
.I 250
.T
An Engineering Application of Logic-Structure Tables
.A
Nickerson, R. C.
.I 251
.T
Ballistic Cam Design
.W
This paper presents a digital computer program
for the rapid calculation of manufacturing data
essential to the design of preproduction cams which
are utilized in ballistic computers of tank fire
control systems.  The cam profile generated introduces
the superelevation angle required by tank main
armament for a particular type ammunition.
.A
Archambault, M.
.I 252
.T
Programming a Duplex Computer System
.W
This paper describes a method of duplex-computer
programming that has been used with two computers
in a military defense system.  The method combines special
programs with a basic data processing program
package.  The duplex operation gives the system greater
reliability.  After achieving the required level
of integration, both computers do similar processing
on the same inputs and continually cross-check the
intermediate and final results.
.A
Dow, J.
.I 253
.T
On a Program for Ray-Chaudhuri's Algorithm
for a Minimum Cover of an Abstract Complex
.A
Foata, D. C.
.I 254
.T
SMALGOL-61
.W
Prior to and during the 1961 Western Joint
Computer Conference, several people in the Joint
Users Groups had expressed interest in defining a "smalgol"
language.  This is to be an ALGOL language
for use with compilers on relatively small size computers.
 A preliminary report resulted.  At the ACM
National Conference four months later, after considering
several counter proposals, a final version was
agreed upon by a subcommittee.  The recommendations
of the Subcommittee for a standard subset of ALGOL
60 for use on small computers is presented here.
.A
Bachelork, G. A.
Dempster, J. R. H.
Knuth, D. E.
Speroni, J.
.I 255
.T
Augmentation (Algorithm 68)
.A
Breed, L. M.
.I 256
.T
A Set of Test Matrices (Algorithm 52)
.A
Dubay, G. H.
.I 257
.T
Invert (Algorithm 42)
.A
Knapp, A. W.
Shaman, P.
.I 258
.T
Composition Generator (Algorithm 72)
.A
Hellerman, O.
Ogden, S.
.I 259
.T
Permutation (Algorithm 71)
.A
Coveyou, R. R.
Sullivan, J. G.
.I 260
.T
Interpolation By Aitken (Algorithm 70)
.A
Mifsud, C. J.
.I 261
.T
Tape Splitting
.A
Moore, D. P.
.I 262
.T
MAP
.A
Moore, C. L.
Ruwe, M. L.
.I 263
.T
Library Loading with Alternate Routine Selection
.A
Moore, D. P.
.I 264
.T
A Generalized Polyphase Merge Algorithm
.A
Reynolds, S. W.
.I 265
.T
Low Level Language Subroutines for Use Within Fortran
.W
This paper describes some subroutines, coded
in symbolic languages and for use within Fortran
coded programs, to deal with "special arithmetic" (e.g.
multi-precision arithmetic), symbol manipulation,
bit manipulation and expanded character set input-output, and visual display.
.A
Barnett, M. P.
.I 266
.T
Fitting Spheres by the Method of Least Squares
.A
Robinson, S. M.
.I 267
.T
Some Proposals for Improving the Efficiency of ALGOL 60
.A
Wilkes, M. V.
.I 268
.T
Stochastic Evaluation of a Static Storage Allocation
.A
Cohen, L. J.
.I 269
.T
Core Allocation Based on Probability
.A
Riskin, B. N.
.I 270
.T
Techniques for Storage Allocation Algorithms
.A
Kelley Jr., J. E.
.I 271
.T
A Semi-Automatic Storage Allocation System at Loading Time
.A
Heising, W. P.
Larner, R. A.
.I 272
.T
A Storage Allocation Scheme for ALGOL 60
.W
A storage allocation scheme for a machine
with a 2048 instruction core store and a magnetic
drum is described.  The use of the drum for storing
program blocks and/or data must be directed by the
programmer through auxiliary information in the ALGOL
program.  The administrative routines controlling
the storage at run time are described in full.  A detailed example is given.
.A
Jensen, J.
Mondrup, P.
Naur, P.
.I 273
.T
Experience in Automatic Storage Allocation
.A
Collins Jr., G. O.
.I 274
.T
Dynamic Storage Allocation in the Atlas Computer,
Including an Automatic Use of a Backing Store
.A
Fotheringham, J.
.I 275
.T
Dynamic Storage Allocation for an Information Retrieval System
.A
Sams, B. H.
.I 276
.T
Program Organization and Record Keeping for Dynamic Storage Allocation
.W
The material presented in this paper is part
of the design plan of the core allocation portion
of the ASCII-MATIC Programming System.  Project ASCII-MATIC
is concerned with the application of computer
techniques to the activities of certain headquarters
military intelligence operations of the U.S. Army.
.A
Holt, A. W.
.I 277
.T
Problems of Storage Allocation in
a Multiprocessor Multiprogrammed System
.A
Maher, R. J.
.I 278
.T
A General Formulation of storage Allocation
.W
Formalization of a general computer storage
allocation process is attempted.  With a given
computer M is associated a fictitious computer M' essentially
identical to M except in respect to possession
of unbounded primary storage.  Mappings of the total
storage set (internal and external) of M into the
direct address set of M' are introduced.  A program
sequence P for M' is termed M-admissible (relative
to a specific execution time period) if there is a mapping
underwhich P and its effective data referents
are all located in the direct address set of M.  Storage
allocation is considered as a process of establishing
for an arbitrary M' program  a sequence of mappings, a decoupling
of the program into M-admissible subprograms
and a linking set of interludes.  An existence proof
in terms of a completely interpretive M program
as indicated.  Some special cases are discussed.  Various
restrictions on generality of M' programs are
considered under which more practical realization
of allocation processes becomes tractable.
.A
Roberts Jr., A. E.
.I 279
.T
The Case for Dynamic storage Allocation
.A
Sams, B. H.
.I 280
.T
A Preplanned Approach to a Storage Allocating Compiler
.A
O'Neil, R. W.
.I 281
.T
Putting a Hex on e^x
.W
Recent notes on approximate natural antilogy
have not considered indirect formulations for
describing e^x.  In this note we produce a particular
family of very fast, high precision and eminently
practical exponential evaluation formulas derived from one such formulation.
.A
Feurzeig, W.
.I 282
.T
Optimum Tape-Writing Procedures
.W
Consider a magnetic tape system with a read
check after writing.  Where an error occurs in
writing a record, a programmed error routine may either
bypass some or all of the area on tape or try
to rewrite the record on the same area.  This paper evaluates
these two procedures on the basis of expected
loss of computer time and develops a decision rule for
selecting the optimum procedure.  The rule depends
critically on the number of times the tape being written
will be used in the future.  In the case where
the optimum procedure is to bypass an area, a second
decision-the size of the area to be bypassed-is
necessary.  A formula is developed to determine the
optimum area to be bypassed for each procedure.
.A
Hutchinson, K.
.I 283
.T
Inversion of a Complex Matrix
.A
Tornheim, L.
.I 284
.T
Manipulation of Algebraic Expressions
.W
An algorithm for algebraically manipulating
expressions of the form SUM{CiPi, i=1,...,n}; has
been developed in conjunction with the development of programs
for systems analysis problems.  This algorithm
enablesus to derive over-all system transfer functions
from algebraically described block diagrams of
any linear continuous multi-loop feedback system.  The
machine representation of the derived expression,
is, by virtue of the algorithm, in a form which simplifies
the task of compiling.  The algorithm was
developed for a particular purpose in connection with
system analysis studies.  However, its application
as a mathematical device extends far beyond
the confines of the original problem.
.A
Rom, A. R. M.
.I 285
.T
Solution of Tridiagonal Matrices
.A
Wenrick, R. C.
Houghton, A. V.
.I 286
.T
An Iterative Method for Inversion of Power Series
.A
Bramhall, J. N.
.I 287
.T
The Generalized Important Event Technique
.A
Shapiro, N.
Vreenegoor, H.
.I 288
.T
A Syntactical Chart of ALGOL 60
.A
Taylor, W.
Turner, L.
Waychoff, R.
.I 289
.T
Critical Path Scheduling (Algorithm 40)
.A
Alexander, N. P.
.I 290
.T
Chain Tracing (Algorithm 69)
.A
Mayoh, B. H.
.I 291
.T
Use of MOBOL in PreparingRetrieval Programs
.A
Hoffman, J.
Opler, A.
.I 292
.T
An Information Retrieval Language for Legal Studies
.A
Kehl, W. B.
Horty, J. F.
Bacon, C. R. T.
Mitchell, D. S.
.I 293
.T
The Applied Mathematics Laboratory of the David W. Taylor Model Basin
.A
Richstone, M.
.I 294
.T
An Imaginary Number System
.A
Knuth, D.
.I 295
.T
Rational Approximations for the Error Function and for Similar Functions
.A
Clendenin, W. W.
.I 296
.T
A Note on Multiple Precision Arithmetic
.A
Cox, A. G.
Luther, H. A.
.I 297
.T
A Note on Fitting Great Circles by Least Squares
.A
Marcus, C. F.
.I 298
.T
A 48-Bit Pseudo-Random Number Generator
.W
A new 48-bit pseudo-random number generator, suitable
for several computers, was tested statistically
for randomness to determine its adequacy for use in Monte
Carlo programs.  Frequency tests, distributions
of certain low-order moments, runs up and down, and runs
above and below the mean were applied to one-half
million generated numbers lying within the interval
(0,1) and to three sets of integers obtained from
specified bits within the generated numbers.  These
tests substantiated the randomness of all numbers
except for the set of integers coming from the least significant bits.
.A
Kuehn, H. G.
.I 299
.T
A Generalized Polyphase Merge Algorithm
.A
Reynolds, S. W.
.I 300
.T
COBOL: A Sample Problem
.W
A simplified Merchandise Control problem has
been chosen for presenting COBOL to users and
potential users of computing systems.  A mythical department
store, "E. Language Bros., Inc.", is programming
in the COBOL language one of the many runs on its computer.
.A
Mackinson, T. N.
.I 301
.T
A Set of Test Matrices (Algorithm 52)
.A
Gilbert, H. E.
.I 302
.T
Augmentation (Algorithm 68)
.A
Rice, H. G.
.I 303
.T
Some Basic Terminology Connected With
Mechanical Languages and Their Processors
.W
The suggestions in this paper are part of the
terminology used in work for the University of
Pennsylvania's Office of computer Research and Education.
 The work is jointly supported by the National
Science Foundation and the Air Force Office of Scientific Research.
.A
Gorn, S.
.I 304
.T
Nth Roots of a Complex Number (Algorithm 53)
.A
Nestor Jr., C. W.
.I 305
.T
CRAM (Algorithm 67)
.A
Caffrey, J.
.I 306
.T
INVRS (Algorithm 66)
.A
Caffery, J.
.I 307
.T
FIND (Algorithm 65)
.A
Hoare, C. A. R.
.I 308
.T
QUICKSORT (Algorithm 64)
.A
Hoare, C. A. R.
.I 309
.T
PARTITION (Algorithm 63)
.A
Hoare, C. A. R.
.I 310
.T
A Set of Associate Legendre Polynomials
of the Second Kind (Algorithm 62)
.A
Herndon, J. R.
.I 311
.T
Procedures for Range Arithmetic (Algorithm 61)
.A
Gibb, A.
.I 312
.T
A Further Note on Approximating e^x
.A
Olivier, D.
.I 313
.T
An Iterative Method for Inversion of Power Series
.A
Bramhall, J. N.
.I 314
.T
A Divisionless Method of Integer Conversion
.A
Clarkson, W. K.
Prince, B. M.
.I 315
.T
Solution of Tridiagonal Matrices
.A
Wenrick, R. C.
.I 316
.T
An Algorithm for Equivalence Declarations
.A
Arden, B. W.
Galler, A.
Graham, R. M.
.I 317
.T
On The Approximation of Curves by Line Segments Using Dynamic Programming
.A
Bellman, R.
.I 318
.T
Combat Vehicle Firing Stability (Active Suspension)
.A
Fischer, C. M.
.I 319
.T
On a Class of Iteration Formulas and Some Historical Notes
.W
The class of iteration formulas obtainable
by rational approximations of "Euler's formula"
is derived with the corresponding error estimates.
Some historical notes on iterative procedures are
followed by a derivation of Euler's formula with the
associated error estimate in a new notation which
simplifies the error estimate and suggests generalizations.
 The final section considers the Pade approximants
to the "Euler polynomial" and shows how a number of known
formulas may be derived from this unified approach.
 There is a short discussion of the "best" formula.
.A
Traub, J. F.
.I 320
.T
Logic-Structure Tables
.W
Logic tables are an excellent way of developing
and expressing the logic required in procedures,
operations, systems and circuits.  A set of rules for
writing and using logic tables is explained by
means of some simple examples.  Then the logic structure
of a vending machine is given in which two logic
tables are used.  Logic tables are two-dimensional in
nature, enabling us to fully express and consider
both the sequential and parallel aspects of logic.  They
can be compiled directly into a computer program
and so eliminate the need for flow charting and hand coding.
.A
Cantrell, H. N.
King, J.
King, F. E. H.
.I 321
.T
ALGOL 60 Confidential
.W
The ALGOL 60 Report,* when first encountered,
seems to describe a very complex language which
will be difficult to learn.  The "metalinguistic formulae"
admirably serve the purpose of precisely specifying
a language, but they are certainly not very readable
for a beginner.  However, experience has shown that
once the report is explained it is in fact easy to learn
ALGOL and to write algorithms in it.  The language
is so general and powerful it can handle an enormous
class of problems.  It is not hard to learn those
parts of ALGOL present in other compiler languages: how
to write assignment and go to and for statements,
etc.  Indeed, a lot of the unnecessary restrictions
imposed by other compiling languages have finally
been lifted.  But ALGOL also allows many unobvious things
to be written, as we will see later, and herein
lies a problem: ALGOL seems to have become too general.
 So many restrictions have been lifted that a
lot of technical details crop up which are hard to learn
and to use correctly.  In this paper some of
the more obscure features of the language are considered
and their usefulness is discussed.  Remarks
are based on the authors' interpretations of the ALGOL 60 Report.
.A
Knuth, D. E.
Merner, J. N.
.I 322
.T
Operational Compatibility of Systems-CONVENTIONS
.W
The General Standards Committee of the SHARE
organization has devoted considerable effort to
the problem of operating a computer efficiently in
view of the growing number of programming systems
available.  Each of these programming systems has been
coded to utilize a fixed set of hardware components
without recognizing the fact that others may be occupying
a storage medium required by the first.  These
incompatibilities are currently resolved by manually setting
up the computer for each system as required.
 The following set of conventions is being considered
to minimize computer set-up time.  They are of
sufficiently broad interest that we feel other computer
users should be aware of them. -George F. Ryckman,
Chairman
.A
Bright, H. S.
.I 323
.T
The State of Digital Computer Technology in Europe
.A
Blachman, N. M.
.I 324
.T
Romberg Integration (Algorithm 60)
.A
Bauer, F. L.
.I 325
.T
Numerical Solution of the Polynomial Equation (Algorithm 30)
.A
Alexander, W. J.
.I 326
.T
MATHSORT (Algorithm 23)
.A
Ranshaw, R. W.
.I 327
.T
Zeros of a Real Polynomial by Resultant Procedure (Algorithm 59)
.A
Bareiss, E. H.
Fisherkeller, M. A.
.I 328
.T
Matrix Inversion (ALgorithm 58)
.A
Cohen, D.
.I 329
.T
Automatic Abstracting and Indexing Survey and Recommendations
.W
In preparation for the widespread use of automatic
scanners which will read documents and transmit
their contents to other machines for analysis, this report
presents a new concept in automatic analysis:
the relative-frequency approach to measuring  the significance
of words, word groups, and sentences.
 The relative-frequency approach is discussed in detail,
as is its application to problems of automatic
indexing and automatic abstracting.  Included in the
report is a summary of automatic analysis studies
published as of the date of writing.  Conclusions are
that point toward more sophisticated mathematical
and linguistic techniques for the solution of problems of automatic analysis.
.A
Edmundson, H. P.
Wyllys, R. E.
.I 330
.T
A Method for Evaluating the Area of the Normal Function
.A
Baker, F. B.
.I 331
.T
Successive Approximations and Computer Storage
Problems in Ordinary Differential Equations
.A
Bellman, R.
.I 332
.T
An Indirect Chaining Method for Addressing on Secondary Keys
.W
Methods for entering random access files on
the basis of one key are briefly surveyed.  The
widely used chaining method, based on a pseudo-random
key transformation, is reviewed in more detail.
 An efficient generalization of the chaining method
which permits recovery on additional keys is then
presented.
.A
Johnson, L. R.
.I 333
.T
Design of an Improved* Transmission/Data Processing Code
.A
Bemer, R. W.
Smith Jr., H. J.
Williams Jr., F. A.
.I 334
.T
Division and Square Root in the Quater-Imaginary Number System
.A
Nadler, M.
.I 335
.T
Some Numerical Experiments Using Newton's Method
for Nonlinear Parabolic and EllipticBoundary-Value
Problems
.W
Using a generalization of Newton's method, a nonlinear
parabolic equation of the form U(t)-U(xx)=g(U)
and a nonlinear elliptic equation U(xx)+U(yy)=exp(U)
are solved numerically Comparison of these results
with results obtained using the Picard iteration procedure
show that in many cases the quisi linearization
method offers substantial advantages in both time and accuracy.
.A
Bellman, R.
Juncosa, M. L.
Kalaba, R.
.I 336
.T
A Practical Technique for the Determination of
the Optimum Relaxation Factor of the Successive
Over-Relaxation Method
.A
Kulsrud, H. E.
.I 337
.T
Further Survey of Punched Card Codes
.A
Ross, H. M.
.I 338
.T
GROUT II (Algorithm 43)
.A
Thacher Jr., H.C.
.I 339
.T
Real Exponential Integral (Algorithm 20)
.A
Alexander, W. J.
Thacher Jr., H. C.
.I 340
.T
Legendre Polynomial (Algorithm 13)
.A
Herndon, J.
.I 341
.T
Chebyschev Polynomial (Algorithm 10)
.A
Herndon, J.
.I 342
.T
Solution of Polynomial Equation by Barstow-Hitchcock (Algorithm 3)
.A
Herndon, J.
.I 343
.T
On Frequently Occurring Errors in ALGOL 60 Programs (Algorithm 25)
.A
Herndon, J.
.I 344
.T
Ber or Bei Function (Algorithm 57)
.A
Herndon, J. R.
.I 345
.T
Complete Elliptic Integral of the Second Kind (Algorithm 56)
.A
Herndon, J. R.
.I 346
.T
Complete Elliptic Integral of the First Kind (Algorithm 55)
.A
Herndon, J. R.
.I 347
.T
Gamma Function for Range 1 to 2 (Algorithm 54)
.A
Herndon, J. R.
.I 348
.T
Nth Roots of a Complex Number (Algorithm 53)
.A
Herndon, J. R.
.I 349
.T
A Set of Test Matrices
.A
Herndon, J. R.
.I 350
.T
Adjust Inverse of a Matrix When an Element is Perturbed (Algorithm 51)
.A
Herndon, J. R.
.I 351
.T
Inverse of a Finite Segment of the Hilbert Matrix (Algorithm 50)
.A
Herndon, J. R.
.I 352
.T
Spherical Neumant Function (Algorithm 49)
.A
Herndon, J. R.
.I 353
.T
Logarithm of A Complex Number (Algorithm 48)
.A
Herndon, J. R.
.I 354
.T
Associated Legendre Functions of the First Kind
for Real or Imaginary Arguments (Algorithm 47)
.A
Herndon, J. R.
.I 355
.T
Exponential of a Complex Number (Algorithm 46)
.A
Herndon, J. R.
.I 356
.T
INTEREST (Algorithm 45)
.A
Ingerman, P. Z.
.I 357
.T
Bessel Functions Computed Recursively (Algorithm 44)
.A
Wojcicki, M. E.
.I 358
.T
Crout with Pivoting II (Algorithm 43)
.A
Thacher Jr., H. C.
.I 359
.T
INVERT (Algorithm 42)
.A
Wood, T. C.
.I 360
.T
Evaluation of Determinant (Algorithm 41)
.A
Solomon, J. G.
.I 361
.T
Programmed Error Correction on a Decimal Computer
.A
Weinberg, G. M.
.I 362
.T
Table Look-At Techniques
.A
Sherman, P. M.
.I 363
.T
On Approximating Transcendental Numbers by Continued Fractions
.A
Karst, E.
.I 364
.T
On the Compilation of Subscripted Variables
.A
Nather, R. E.
.I 365
.T
Bessel Functions of Integral Order and Complex Argument
.A
Gray, M. C.
.I 366
.T
Eigenvalues of a Symmetric 3 x 3 Matrix
.A
Smith, O. K.
.I 367
.T
Topological Ordering of a List of
Randomly-Numbered Elements of a Network
.W
A network of directed line segments free of circular
elements is assumed.  The lines are identified
by their terminal nodes and the nodes are assumed to
be numbered by a non-topological system.  Given
a list of these lines in numeric order, a simple technique
can be used to create at high speed a list
in topological order.
.A
Lasser, D. J.
.I 368
.T
Real Zeros of an Arbitrary Function (Algorithm 25)
.A
Collinge, R. M.
.I 369
.T
Crout with Pivoting (Algorithm 16)
.A
Thacher Jr., H. C.
.I 370
.T
Bisection Routine (Algorithm 4)
.A
Rader, P. J.
.I 371
.T
Remarks on Algorithms 2 and 3, Algorithm 15 and Algorithms 25 and 26
.A
Wilkinson, J. H.
.I 372
.T
Critical Path Scheduling (Algorithm 40)
.A
Leavenworth, B.
.I 373
.T
Correlation Coefficients with Matrix Multiplication (Algorithm 39)
.A
Sassouni, P.
.I 374
.T
Telescope2 (Algorithm 38)
.A
Brons, K. A.
.I 375
.T
Telescope1 (Algorithm 37)
.A
Brons, K. A.
.I 376
.T
Tchebycheff (Algorithm 36)
.A
Gianni, A. J.
.I 377
.T
SIEVE (Algorithm 35)
.A
Wood, T. C.
.I 378
.T
A Generalized Technique for Symbol
Manipulation and Numerical Calculation
.A
Ross, D. T.
.I 379
.T
Bitwise Operations
.A
Strachey, C.
.I 380
.T
Comparison of Iterative Methods for the Calculation of nth Roots
.W
Three iterative methods for calculation of
nth roots (including one proposed by the author)
are compared in two ways: (1) Theoretical convergence
estimates are given.  (2) A new macrocompiler which
estimates machine running time is used to compare the
running time of the three methods for a variety
of input data.
.A
Traub, J. F.
.I 381
.T
An Alternate Form of the "UNCOL Diagram"
.A
Bratman, H.
.I 382
.T
Statistical Programs at the University of North Carolina
.A
Bush, N.
.I 383
.T
On Finding Minimum Routes in a Network With Turn Penalties
.A
Caldwell, T.
.I 384
.T
Gamma Function (Algorithm 34)
.A
Lipp, M. F.
.I 385
.T
FACTORIAL (Algorithm 33)
.A
Lipp, M. F.
.I 386
.T
MULTINT (Algorithm 32)
.A
Freeman Jr., R. D.
.I 387
.T
Gamma Function (Algorithm 31)
.A
Collinge,R. M.
.I 388
.T
Solution of Polynomial Equations by
Bairstow Hitchcock Method (Algorithm 3)
.A
Vandergraft, J. S.
.I 389
.T
Real Exponential Integral (Algorithm 20)
.A
Peavy, S.
.I 390
.T
Complex Exponential Integral (Algorithm 13)
.A
Rader, P. J.
Thacher Jr., H. C.
.I 391
.T
The BKS System for the Philco-2000
.A
Smith, R. B.
.I 392
.T
Comment on A Paper on Parallel Processing
.A
Nekora, M. R.
.I 393
.T
Two Subroutines for Symbol Manipulation with an Algebraic Compiler
.A
Carr III, J. W.
Hanson, J. W.
.I 394
.T
Multiple Programming Data Processing
.A
Ryle, B. L.
.I 395
.T
Multiple-Precision Division
.A
Rabinowitz, P.
.I 396
.T
   Automation of Program  Debugging
.W
   Automatic Debugging can substantially reduce lead-time between the coding
and the effective use of a complex program. It also enforces analysis of
debugging criteria, resulting in verifiably accurate programs. The programmer
specifies the program to be debugged, memory areas, set of input data, maximum
repetition of loops, and checkpoint information for each set of data. The
executive debugging program the runs the program to be debugged, performing
checking functions and creating a trace record of its own later analysis and
location of errors. Applications are quite flexible, and the system can be used
alone or in conjunction with other debugging techniques.
.A
Jacoby, K.
Layton, H.
.I 397
.T
A Card Format for Reference Files in Information Processing
.W
This paper proposes a card format suitable for
a variety of reference files in information
processing.  An 80-column IBM card is divided into two
fields-reference material field (columns 1-67)
and identification field (columns 68-80).  The format
for the reference material is flexible, while the
format for the identification is rigid.  The reference
material includes basically an index, title, source,
class, summary and cross reference for each entry.
The identification includes basically codes for a
matrix of descriptors, an entry number, and the kind,
major interest, and source of the reference.  The
identification also provides a choice to identify material
for personal as well as general files.  Since
this card format is sufficient to identify the material
normally associated with reference files for
books, articles, programming terms, hardware terms, equipment,
machine systems, abbreviations, etc., it
is suitable as a standard for card reference files in information processing.
.A
Grems, M.
.I 398
.T
The SLANG System
.A
Sibley, R. A.
.I 399
.T
Compiling Techniques for Boolean Expressions
and Conditional Statements in ALGOL 60
.A
Huskey, H. D.
Wattenburg, W. H.
.I 400
.T
Comments on the Implementation of Recursive
Procedures and Blocks in ALGOL 60
.A
Irons, E. T.
Feurzeig, W.
.I 401
.T
Allocation of Storage for Arrays in ALGOL 60
.A
Sattley, K.
.I 402
.T
Dynamic Declarations
.A
Ingerman, P. Z.
.I 403
.T
Thunks -- A Way of Compiling Procedure Statements
with Some Comments on Procedure Declarations
.A
Ingerman, P. Z.
.I 404
.T
A Syntax Directed Compiler for ALGOL 60
.A
Irons, E. T.
.I 405
.T
An Algorithm for Coding Efficient Arithmetic Operations
.W
Most existing formula translation schemes
yield inefficient coding.  A method is described
which reduces the number of store and fetch operations,
evaluates constant subexpressions during compilation,
and recognizes many equivalent subexpressions.
.A
Floyd, R. W.
.I 406
.T
The Use of Threaded Lists in Constructing a Combined
ALGOL and Machine-Like Assembly Processor
.A
Evans Jr., A.
Perlis, A. J.
Van Zoeren, H.
.I 407
.T
MADCAP: A Scientific Compiler for a Displayed Formula Textbook Language
.A
Wells, M. B.
.I 408
.T
The Internal Organization of the MAD Translator
.A
Arden, B. W.
Galler, B. A.
Graham, R. M.
.I 409
.T
CL-1, An Environment for a Compiler
.W
A flexible, large-scale programming system to
facilitate the solution of information processing
problems and to provide intercommunication between programs
and/or programmers has been developed and
realized on the IBM 709/7090 computer.  The system is
based on a master file concept and has provisions
for accepting, storing, and retrieving both descriptions
and instances of large and complex data sets,
as well as algorithms defined on these data sets.  Both
data and algorithms may be expressed in a family
of command and descriptive languages.  The concept
of distinct data descriptions and the content and
use of such descriptions are discussed in some detail.
.A
Cheatham Jr., T. E.
Collins Jr., G. O.
Leonard, G. F.
.I 410
.T
The CLIP Translator
.A
Englund, D.
Clark, E.
.I 411
.T
Use of Magnetic Tape for Data Storage in the ORACLE-ALGOL Translator
.A
Bottenbruch, H.
.I 412
.T
Recursive Processes and ALGOL Translation
.A
Gray, A. A.
.I 413
.T
A Basic Compiler for Arithmetic Expressions
.A
Huskey, H. D.
Wattenburg, W. H.
.I 414
.T
IBM 1440 Data Processing System Features Five New Units
.W
The IBM 1440 data processing system, announced
recently by the International Business Machines
Corporation, not only features the 1311 disk storage
drive with interchangeable disk packs but four other
newly developed units.
.A
Wheeling, R.
.I 415
.T
The Use of Digital Computers in Western Germany
.A
Schuff, H. K.
.I 416
.T
Multiple Shooting Method for Two-Point Boundary Value Problems
.A
Morrison, D. D.
Riley, J. D.
Zancanaro, J. F.
.I 417
.T
Legal Implications of Computer Use
.W
This paper points out a variety of ways computer
systems used in business and industry can
be involved in legal entanglements and suggests that
computer specialists have a responsibility to call
for assistance in forestalling or minimizing those entanglements
during the planning stage.  Techniques
are suggested for making legal clearance effective with
the least burden on the new technology and for
achieving a favorable legal climate for it generally.
 Computer specialists also are alerted to potential
opportunities to interpret to lawyers the technical aspects
of computer systems involved in legal situations.
.A
Freed, R. N.
.I 418
.T
RANDOM (Algorithm 133)
.A
Behrenz, P. G.
.I 419
.T
Magic Square (Algorithm 118)
.A
Thacher Jr., H. C.
.I 420
.T
PERM (Algorithm 115)
.A
Phillips, E. S.
.I 421
.T
Position of Point Relative to Polygon (Algorithm 112)
.A
Hacker, R.
.I 422
.T
COMBINATION (Algorithm 94)
.A
Grench, R. E.
.I 423
.T
Matrix Inversion (Algorithm 58)
.A
Behrenz, P. G.
.I 424
.T
Gamma Function (Algorithm 31)
.A
Behrenz, P. G.
.I 425
.T
Complete Elliptic Integral (Algorithm 149)
.A
Merner, J. N.
.I 426
.T
Term of Magic Square (Algorithm 148)
.A
Collison, D. M.
.I 427
.T
PSIF (Algorithm 147)
.A
Amit, D.
.I 428
.T
Multiple Integration (Algorithm 146)
.A
McKeeman, W. M.
.I 429
.T
Adaptive Nimerical Integration by Simpson's Rule (Algorithm 145)
.A
McKeeman, W. M.
.I 430
.T
TREESORT2 (Algorithm 144)
.A
Kaupe Jr.,A. F.
.I 431
.T
TREESORT1 (Algorithm 143)
.A
Kaupe Jr., A. F.
.I 432
.T
Triangular Regression (Algorithm 142)
.A
Hafley, W. L.
Lewis, J. S.
.I 433
.T
Fixed-World-Length Arrays in Variable-Word-Length Computers
.A
Sonquist, J. A.
.I 434
.T
Character Manipulation in 1620 Fortran II
.A
Poore Jr., J. H.
.I 435
.T
A Decision Matrix as the Basis for a Simple Data Input Routine
.W
Currently a great deal of time and effort is
being spent on the development of bigger and better
compiler languages, multiprogram executive systems,
etc.  Since the implementation of  of new methods
and procedures is not instantaneous, but rather occurs
by an evolutionary process, we should be concerned
also with the problem of maintaining, improving and
incorporating new ideas into existing systems.  It
is with this somewhat neglected area that the author is
interested.  A method employing a decision matrix
is presented for the handling of a standard systems
programming problem,that of providing a data input
routine.
.A
Vasilakos, G. J.
.I 436
.T
Evaluation of Polynomials by Computer
.A
Knuth, D. E.
.I 437
.T
Compiling Matrix Operations
.A
Galler, B. A.
Perlis, A. J.
.I 438
.T
Mechanical Pragmatics: A Time-Motion Study
of a Miniature Mechanical Linguistic System
.A
Gorn, S.
.I 439
.T
On-Line Digital Computer for Measurement of a Neurological Control System
.A
Stark, L.
Payne, R.
Okabe, Y.
.I 440
.T
Record Linkage
.W
Special difficulties are encountered in devising
reliable systems for searching and updating
any large files of documents that must be identified
primarily on the basis of names and other personal
particulars.  The underlying problem is that of making nearly
maximum use of items of identifying information
that are individually unreliable but that may collectively
be of considerable discriminating power.
Rules that can be applied generally to name retrieval
systems have been developed in a methodological
study of the linkage of vital and health records into
family groupings for demographic research purposes.
 These rules are described, and the ways in which information
utilization for matching may be optimized
are discussed.
.A
Newcombe, H. B.
Kennedy, J. M.
.I 441
.T
Topological Sorting of Large Networks
.W
Topological Sorting is a procedure required
for many problems involving analysis of networks.
 An example of one such problem is PERT.  The present
paper presents a very general method for obtaining
topological order.  It permits treatment of larger networks
than can be handled on present procedures
and achieves this with greater efficiency.  Although
the procedure can be adapted to any machine, it
is discussed in terms of the 7090.  A PERT network of
30,000 activities can be ordered in less than one
hour of machine time.  The method was developed as
a byproduct of procedures needed by Westinghouse,
Baltimore.  It has not been programmed and at present
there are no plans to implement it.  In regard
to the techniques described, Westinghouse's present
and anticipated needs are completely served by the
Lockheed program, which is in current use.
.A
Kahn, A. B.
.I 442
.T
Crout with Equilibration and Iteration (Algorithm 135)
.A
McKeeman, W. M.
.I 443
.T
Complex Number to a Real Power (Algorithm 106)
.A
Erwin Jr.,G. W.
.I 444
.T
Evaluation of Jacobi Symbol (Algorithm 99)
.A
May, R. W.
.I 445
.T
COMBINATION (Algorithm 94)
.A
May, R. W.
.I 446
.T
Simpson's Integration (Algorithm 84)
.A
Behrenz, P. G.
.I 447
.T
Certification of the Calculation of Easter
.A
Williams, M. R.
.I 448
.T
Path Matrix (Algorithm 141)
.A
Ingerman, P. Z.
.I 449
.T
Matrix Inversion(Algorithm 140)
.A
Ingerman, P. Z.
.I 450
.T
Solution of the Diophantine Equation (Algorithm 139)
.A
Peck, J. E. L.
.I 451
.T
Nesting of for Statement II (Algorithm 138)
.A
Dahm, D. M.
Wells, M.
.I 452
.T
Nesting of for Statement I (Algorithm 137)
.A
Dahm, D. M.
Wells, M.
.I 453
.T
Enlargement of a Group (Algorithm 136)
.A
Wells, M.
.I 454
.T
Crout with Equilibration and Iteration (Algorithm 135)
.A
McKeeman, W. M.
.I 455
.T
Exponentiation of Series (Algorithm 134)
.A
Fettis, H. E.
.I 456
.T
RANDOM (Algorithm 133)
.A
Behrenz, P. G.
.I 457
.T
Quantum Mechanical Integrals Over all Slater-Type Integrals
.A
Browne, J. C.
.I 458
.T
Coefficient Determination (Algorithm 131)
.A
Smith, V. H.
Allen, M. L.
.I 459
.T
PERMUTE (Algorithm 130)
.A
Eaves, Lt. B. C.
.I 460
.T
MINIFUN (Algorithm 129)
.A
Whitley, V. W.
.I 461
.T
Coding of Medical Case History Data for Computer Analysis
.A
Lipkin, M.
Woodbury, M. A.
.I 462
.T
Computer Pattern Recognition Techniques: Electrocardiographic Diagnosis
.W
The use of programmed digital computers as general
pattern classification and recognition devices
is one phase of the current lively interest in artificial
intelligence.  It is important to choose a
class of signals which is, at present, undergoing a
good deal of visual inspection by trained people
for the purpose of pattern recognition.  In this way
comparisons between machine and human performance
may be obtained.  A practical result also serves as additional
motivation.  Clinical electrocardiograms
make up such a class of signals.  The approach to the
problem presented here centers upon the use of
multiple adaptive matched filters that classify normalized
signals.  The present report fives some of
the background for the application of this method.
.A
Stark,L.
Okajima, M.
Whipple, G. H.
.I 463
.T
On Ambiguity in Phrase Structure Languages
.A
Floyd, R. W.
.I 464
.T
Syntactic Analysis by Digital Computer
.W
This paper provides an account of the Shadow
language that is used to describe syntax and of
a corresponding subroutine that enables a computer
to perform syntactic analysis.  The input to this
subroutine consists of a string to be analyzed and a
description of the syntax that is to be used.  The
syntax is expressed in the Shadow language.  The output
consists of a trace table that expresses the
results of the syntactic analysis in a tabular form.  Several
versions of the subroutine and some associated
programs have been in use now for over three years.  The
present account of the language and the subroutine
contains a summary of material that has been described
previously in unpublished reports and also some
additional discussion of the work in relation to the more
general questions of problem-oriented languages
and string transformations.
.A
Barnett, M. P.
Futrelle, R. P.
.I 465
.T
PERM (Algorithm 115)
.A
Schrack, G. F.
.I 466
.T
General Order Arithmetic (Algorithm 93)
.A
George, R.
.I 467
.T
Permutation Generator (Algorithm 87)
.A
Schrack, G. F.
Shimrat, M.
.I 468
.T
Incomplete Elliptic Integrals (Algorithm 73)
.A
Jefferson, D. K.
.I 469
.T
Critical Path Scheduling (Algorithm 40)
.A
Hellberg, L.
.I 470
.T
Summation of Fourier Series (Algorithm 128)
.A
Wells, M.
.I 471
.T
ORTHO (Algorithm 127)
.A
Walsh, P. J.
.I 472
.T
Gauss' Method (Algorithm 126)
.A
Counts, J. W.
.I 473
.T
WEIGHTCOEFF (Algorithm 125)
.A
Rutishauser, H.
.I 474
.T
Input Data Organization in Fortran
.A
Yarbrough, L.D.
.I 475
.T
A Test Matrix for Inversion Procedures
.A
Pei, M. L.
.I 476
.T
Further Remarks on Sampling a Tape File-II
.A
Nadler, M.
.I 477
.T
Further Remarks on Sampling a Tape File-I
.A
Muller, M. E.
.I 478
.T
Implementing a Stack
.A
Baecker, H.D.
.I 479
.T
A Dispersion Pass Algorithm for the Polyphase Merge
.W
This paper presents a new manner of dispersing
strings for a Polyphase merge.  If the number
of strings dispersed is between two levels acceptable
by Polyphase merge, a more economical technique
of reaching the next level for Polyphase merge is shown and proved.
.A
Mendoza, A. G.
.I 480
.T
Quick Calculation of Jacobian Elliptic Functions (Corrigendum)
.A
Salzer, H. E.
.I 481
.T
A One-Day Look At Computing
.A
Armerding, G. W.
Gruenberger, F. J.
Marks, S. L.
Parkin, T. R.
.I 482
.T
TALL-A List Processor for the Philco 200 Computer
.A
Feldman, J.
.I 483
.T
On the Nonexistence of a Phrase Structure Grammar for ALGOL 60
.W
ALGOL 60 is defined partly by formal mechanisms
of phrase structure grammar, partly by informally
stated restrictions.  It is shown that no formal mechanisms
of the type used are sufficient to define
ALGOL 60.
.A
Floyd, R. W.
.I 484
.T
Hankel Function (Algorithm 124)
.A
Schaefer, L. J.
.I 485
.T
Real Error Function, ERF(x) (Algorithm 123)
.A
Crawford, M.
Techo, R.
.I 486
.T
Tridiagonal Matrix (Algorithm 122)
.A
Dietzel, G. F.
.I 487
.T
NORMDEV (Algorithm 121)
.A
Shafer,D.
.I 488
.T
A Heuristic for Page Turning In a Multiprogrammed Computer
.A
Weil, J. W.
.I 489
.T
Current Status of IPL-V for the Philco 2000 Computer (June 1962)
.A
Shaffer, S. S.
.I 490
.T
Programmed Methods for Printer Graphical Output
.A
Garfinkel, D.
.I 491
.T
Use of Multiprogramming in the Design of a Low Cost Digital Computer
.A
Penny, J. P.
Pearcey, T.
.I 492
.T
Analysis of a File Addressing Method
.W
This paper presents a new file addressing method
based on the calculation of an address from
the identification of a record.  For large recirculating
type files, it seems to be more advantageous
than customary ones.  The probability distribution of
the displacement of records from their calculated
address, which is one less than the number of probes
required to address a record, is computed on the
basis of a Markov chain model.  For the reader not interested
in the mathematics, the introduction and
the summary should be sufficient.
.A
Schay Jr., G.
Spruth, W. G.
.I 493
.T
The Property Classification Method of File Design and Processing
.A
McGee, W. C.
.I 494
.T
A Finite Sequentially Compact Process for the Adjoints
of Matrices Over Arbitrary Integral Domains
.A
Luther, H. A.
Guseman Jr., L. F.
.I 495
.T
A Procedure for Inverting Large Symmetric Matrices
.W
In the least squares method for simultaneous
adjustment of several parameters, the coefficients
of the normal equations are the elements of a symmetric
positive-definite matrix.  In order to solve
the normal equations and evaluate the precision measures
of the resulting parameters, inversion of this
matrix of coefficients is required.  Many available procedures
for matrix inversion do not take advantage
of the symmetry.  Thus, when programmed for a high-speed
computer, all n^2 elements must be stored and
manipulated, whereas only (n + 1)/2 of them are independent.
 In order to allow a computer of given memory
capacity to handle a larger matrix, the following procedure
for inverting a symmetric matrix has been
devised.
.A
Busing, W. R.
Levy, H. S.
.I 496
.T
A Set of Matrices for Testing Computer Programs
.A
Brenner, J. L.
.I 497
.T
Further Remarks on Line Segment Curve-Fitting Using Dynamic Programming
.W
In a recent paper, Bellman showed how dynamic
programming could be used to determine the solution
to a problem previously considered by Stone.  The problem
comprises the determination, given N, of the
N points of subdivision of a given interval (a,B) and
the corresponding line segments, that give the
best least squares fit to a function g(x) in the interval.
 Bellman confined himself primarily to the
analytical derivation, suggesting briefly, however,
how the solution of the equation derived for each
particular point of subdivision u(i) could be reduced to
a discrete search.  In this paper, the computational
procedure is considered more fully, and the similarities
to some of Stone's equations are indicated.
 It is further shown that an equation for u(i) involving
no minimization may be found.  In addition,
it is shown how Bellman's method may be applied to the
curve-fitting problem when the additional constraints
are added that the ends of the line segments must be on the curve.
.A
Gluss, B.
.I 498
.T
Magic Square (Algorithm 117 & 118)
.A
Collison, D. M.
.I 499
.T
Permutation Generator (Algorithm 87)
.A
Collison, D. M.
.I 500
.T
PERMUTE (Algorithm 86)
.A
Collison, D. M.
.I 501
.T
JACOBI (Algorithm 85)
.A
Hillmore, J. S.
.I 502
.T
Simpson's Integration (Algorithm 84)
.A
George, R.
.I 503
.T
Rational Roots of Polynomials with Integer Coefficients (Algorithm 78)
.A
Collison, D. M.
.I 504
.T
FACTORS (Algorithm 75)
.A
Hillmore, J. S.
.I 505
.T
Composition Generator (Algorithm 72)
.A
Collison, D. M.
.I 506
.T
PERMUTATION (Algorithm 71)
.A
Hillmore, J. S.
.I 507
.T
Partition, Quicksort, Find (Algorithm 63, 64, 65)
.A
Hillmore, J. S.
.I 508
.T
Matrix Inversion (Algorithm 58)
.A
George, R.
.I 509
.T
Matrix Inversion (Algorithm 58)
.A
Struble, G.
.I 510
.T
Ber or Bei Function (Algorithm 57)
.A
Thacher Jr., H. C.
.I 511
.T
A Set of Test Matrices (Algorithm 52)
.A
Hillmore, J. S.
.I 512
.T
Telescope 1 (Algorithm 37)
.A
Thacher Jr., H. C.
.I 513
.T
SIEVE (Algorithm 35)
.A
Hillmore, J. S.
.I 514
.T
Binomial Coefficients (Algorithm 19)
.A
George, R.
.I 515
.T
Rational Interpolation by Continued Fractions (Algorithm 18)
.A
Thacher Jr., H. C.
.I 516
.T
Matrix Inversion II (Algorithm 120)
.A
George, R.
.I 517
.T
Evaluation of Pert Network (Algorithm 119)
.A
Eisenman, B.
Shapiro, M.
.I 518
.T
Magic Square (Odd Order) (Algorithm 118)
.A
Collison, D. M.
.I 519
.T
Magic Square (Even Order) (Algorithm 117)
.A
Collison, D. M.
.I 520
.T
Complex Division (Algorithm 116)
.A
Smith, R. L.
.I 521
.T
PERM (Algorithm 115)
.A
Trotter, H. F.
.I 522
.T
Generation of Partitions with Constraints (Algorithm 114)
.A
Stockmal, F.
.I 523
.T
TREESORT (Algorithm 113)
.A
Floyd,R. W.
.I 524
.T
Position of Point Relative to Polygon (Algorithm 112)
.A
Shimrat, M.
.I 525
.T
A Computer Technique for Handling Analysis of Variance
.A
Howell, J. R.
.I 526
.T
Character Manipulation in Fortran
.A
Pyle, I. C.
.I 527
.T
The Description List of Concepts
.W
A concept is defined as a class of objects
whose members can be distinguished by processing
its properties.  Property is defined to mean a partition
of the set of all objects into disjoint classes.
 The formal definition of a concept is recursive in nature.
 A concept is described by a list structure.
 A one-to-one correspondence is established between the
recursive definition of a concept and its description
list structure.  Like the definition, the description
list structure of a concept is also built up from
elementary list structures by a recursive process.
The list structures obtained this way are compared
with the description list structure discussed
by the author in a previous publication.
.A
Banerji, R. B.
.I 528
.T
FORTRAN for Business Data Processing
.A
Robbins, D. K.
.I 529
.T
Regression and Coded Patterns in Data Editing
.A
Robison, D. E.
Aroian, L. A.
.I 530
.T
A Computer Method for Radiation Treatment Planning
.A
Siler, W.
Laughlin, J. S.
.I 531
.T
Person-Matching by Electronic Methods
.W
Record linkage in the updating of files is
accomplished in many establishments through the
use of a preassigned number, such as payroll number,
customer number, or social security number.  In
vital and health records, however, a unique number
is generally not preassigned to an individual for
purposes of reporting services received to the health
department.  In order to determine whether different
physician reports refer to the same individual, name
and other identification must be compared.  This
is a laborious operation which is subject to various
errors because of name misspellings, changes of
name upon marriage, and other problems.  We are interested
in the maintenance of a psychiatric case register
in Maryland, where many of the reports from over a hundred
psychiatric agencies refer to the same patient.
 These records must be linked in order to provide unduplicated
counts of individuals under care and longitudinal
records of psychiatric history.  An earlier paper [1] describes
our general procedures for register maintenance
by use of a digital computer (Honeywell 800).  Here
we present in more detail our initial procedures
for the person-matching process in order to elicit comments
and suggestions from persons who have had
experience in matching.
.A
Phillips Jr., W.
Bahn, A. K.
Miyasaki, M.
.I 532
.T
On the Computation of Rational Approximations to Continuous Functions
.A
Fraser, W.
HArt, J. F.
.I 533
.T
Digital Synthesis of Correlated Stationary Noise
.W
In this note we propose a method of generating
stationary noise with a prescribed auto-covariance
function by digital methods.  The need for such a technique
often arises in testing the performance of
data processing and engineering systems, where inputs
corrupted with correlated noise (of a known form)
are required.  The technique is quite simple and produces
strict-sense stationary noise which agrees
approximately with R(t), the prescribed auto-covariance
function (acf), over an interval [-T(0), T(0)].
 The method consists of approximating the spectral density
by a periodic process with spectral lines,
and then synthesizing the periodic noise with random
phases and appropriate amplitudes.  In order to
simplify discussion of the statistical properties of the
noise generated, the technique is first presented
in terms of exact harmonic analysis.  In practice, discrete
harmonic analysis as presented in the third
section is used.
.A
Peabody, P. R.
Adorno, D. S.
.I 534
.T
Quick Calculation of Jacobian Elliptic Functions
.A
Salzer, H. E.
.I 535
.T
Triangular Walk Pattern for the Down-hill
Method of Solving a Transcendental Equation
.A
Onoe, M.
.I 536
.T
Nonlinear Regression and the Solution of Simultaneous Equations
.W
If one has a set of observables (Z1,...,Zm) which
are bound in a relation with certain parameters
(A1,...,An) by an equation S(Z1,...;A1,...)=0, one frequently
has the problem of determining a set of
values of the Ai which minimizes the sum of squares of
differences between observed and calculated values
of a distinguished observable, say Zm.  If the solution
of the above equation for Zm,  Zm=N(Z1,...;A1,...)
gives rise to a function N which is nonlinear in the Ai,
then one may rely on a version of Gaussian regression
[1,2] for an iteration scheme that converges to a minimizing
set of values.  It is shown here that this
same minimization technique may be used for the solution
of simultaneous (not necessarily linear) equations.
.A
Baer, R. M.
.I 537
.T
A Machine Program for Theorem-Proving
.W
The program of a proof procedure is discussed in
connection with trial runs and possible improvements.
.A
Davis, M.
Logemann, G.
Loveland, D.
.I 538
.T
Quantum Mechanical Integrals of Slater-Type Orbitals (Algorithm 110)
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 539
.T
Definite Exponential Integrals B (Algorithm 109)
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 540
.T
Definite Exponential Integrals A (Algorithm 108)
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 541
.T
Simpson's Integration (Algorithm 84)
.A
Relph, A. P.
.I 542
.T
FACTORS (Algorithm 75)
.A
Relph, A. P.
.I 543
.T
Interpolation by Aitken (Algorithm 70)
.A
Relph, A. P.
.I 544
.T
 Ber or Bei Function (Algorithm 57)
.A
Relph, A. P.
.I 545
.T
Adjust Inverse of a Matrix when an Element is Perturbed (Algorithm 51)
.A
George, R.
.I 546
.T
Logarithm of a Complex Number (Algorithm 48)
.A
Johnson, M. L.
Sangren, W.
.I 547
.T
Gamma Function (Algorithm 34)
.A
Johnson, M. L.
Sangren, W.
.I 548
.T
Molecular-Orbital Calculation of Molecular Interactions
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 549
.T
Quantum Mechanical Integrals of Slater-Type Orbitals
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 550
.T
Definite Exponential Integrals B (Algorithm 109)
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 551
.T
Definite Exponential Integrals A (Algorithm 108)
.A
Kruglyak, Y. A.
Whitman, D. R.
.I 552
.T
Gauss's Method (Algorithm 107)
.A
Counts, J. W.
.I 553
.T
Complex Number to a Real Power (Algorithm 106)
.A
Johnson, M. L.
Sangren, W.
.I 554
.T
Newton Maehly, (Algorithm 105)
.A
Bauer, F. L.
Stoer, J.
.I 555
.T
Reduction to Jacobi (Algorithm 104)
.A
Rutishausr, H.
.I 556
.T
On Translation of Boolean Expressions
.A
Bottenbirruch, H. H
Grau, A. A.
.I 557
.T
Simulation of Computer Timing Device
.I 558
.T
A Modified Inversion Procedure for Product
Form of the Inverse Linear Programming Codes
.W
This paper describes a new algorithm for the
selection of the pivot row in matrix inversion
when using the product form of the inverse.  This algorithm
has been developed for linear programming
codes; however, it would be valuable for the inversion
of any non-dense matrix.  The procedures described
in this paper have been thoroughly tested and have been
in operation on the Esso Research and Engineering
IBM 7090 computer for nine months.  Substantial computer
cost savings have been realized because of this
procedure.
.A
Larsen, L. J.
.I 559
.T
Solution of Eigenvalue Problems With Approximately Known Eigenvectors
.A
Appel, K.
.I 560
.T
Communication Between Independently Translated Blocks
.A
Wegner, P.
.I 561
.T
Analytic Differentiation By Computer
.A
Hanson, J. W.
Caviness, J. S.
Joseph, C.
.I 562
.T
AVINT (Algorithm 77)
.A
Whittier, V. E.
.I 563
.T
Sorting Procedures (Algorithm 76)
.A
Randell, B.
.I 564
.T
CRAM (Algorithm 67)
.A
Relph, A. P.
.I 565
.T
INVRS (Algorithm 66)
.A
Caffrey, J.
.I 566
.T
Matrix Inversion (Algorithm 58)
.A
Conger, R. A.
.I 567
.T
Logarithm of a Complex Number (Algorithm 48)
.A
Relph, A. P.
.I 568
.T
Exponential of a Complex Number (Algorithm 46)
.A
Relph, A. P.
.I 569
.T
Binomial Coefficients (Algorithm 19)
.A
Steck, B.
.I 570
.T
Simpson's Rule Integrator (Algorithm 103)
.A
Kuncir, G. F.
.I 571
.T
Permutation in Lexicographical Order (Algorithm 102)
.A
Schrack, G. F.
Shimrat, M.
.I 572
.T
Add Item to Chain-Linked List (Algorithm 100)
.A
Kiviat, P. J.
.I 573
.T
Remove Item From Chain-Linked List (Algorithm 101)
.A
Kiviat, P. J.
.I 574
.T
Evaluation of Jacobi Symbol (Algorithm 99)
.A
Garland, S. J.
Knapp, A. W.
.I 575
.T
Evaluation of Definite Complex Line Integrals (Algorithm 98)
.A
Pfaltz, J. L.
.I 576
.T
Shortest Path (Algorithm 97)
.A
Floyd, R. W.
.I 577
.T
ANCESTOR (Algorithm 96)
.A
Floyd, R. W.
.I 578
.T
Generation of Partitions in Part-Count Form (Algorithm 95)
.A
Stockmal, F.
.I 579
.T
COMBINATION (Algorithm 94)
.A
Kurtzberg, J.
.I 580
.T
General Order Arithmetic (Algorithm 93)
.A
Perstein, M. H.
.I 581
.T
A Note on Sampling a Tape-File
.A
Jones, T. G.
.I 582
.T
One Lost Bit
.A
Oster, C. A.
.I 583
.T
A Redundancy Check for ALGOL Programs
.A
Thacher Jr., H. C.
.I 584
.T
Report on the Algorithmic Language FORTRAN II
.A
Rabinowitz, I. N.
.I 585
.T
Initial Experience With an Operating Multiprogramming System
.W
The Lewis Research Center has been using various
forms and degrees of program simultaneity
in the operation of its modified Sperry-Rand Univac Scientific
Model 1103 computer during the last five
years.  This simultaneity has evolved from an initial
achievement of self-searching input and output
to the automatic time sharing of independently coded
problems.  Several important machine and program
system modifications were necessary to accomplish this
evolution.  Several additional modifications,
although not required, were added to facilitate ease
of coding and operation.  All modifications had
to proceed at a relatively temperate pace to insure that
the basic data-reduction work load of the computing
center was completed on schedule.  Some educationally
valuable mistakes were made, and their suggested
cures often pointed the way to useful future improvements
or emphasized some of the basic principles
of a multiprogramming system.  The material that follows
is a description of the evolution of the programming
and hardware system which has developed into the present
multiprogramming system at Lewis research Center.
.A
Landis, N.
Manos, A.
Turner, L. R.
.I 586
.T
Simultaneous System of Equations and
Matrix Inversion Routine (Algorithm 92)
.A
Roek, D. J.
.I 587
.T
Romberg Integration (Algorithm 60)
.A
Buchner, K. H.
.I 588
.T
Chebyshev Curve-Fit (Algorithm 91)
.A
Newhouse, A.
.I 589
.T
Evaluation of the Fresnel Cosine Integral (Algorithm 90)
.A
Cundiff, J. L.
.I 590
.T
Evaluation of the Fresnel Sine Integral (Algorithm 89)
.A
Cundiff, J. L.
.I 591
.T
Evaluation of Asymptotic Expression for the
Fresnel Sine and Cosine Integrals (Algorithm 88)
.A
Cundiff, J. L.
.I 592
.T
COBOL Batching Problems
.A
Mullen, J. W.
.I 593
.T
An Introduction to a Machine-Independent Data Division
.A
Mullin, J. P.
.I 594
.T
An Advanced Input-Output System for a COBOL Compiler
.A
Bouman, C. A.
.I 595
.T
Guides to Teaching COBOL
.W
The teaching of COBOL can be divided into
three main subject areas.  They are the syntax of
COBOL, the use of such syntax in solving any given problem,
and programming concepts.  It is generally
accepted that some knowledge of the hardware and computer
logic must be possessed by the programmer.
 The teaching problem arises in determining how thoroughly
a student must know the hardware and logic
for that computer for which he will write COBOL programs.
 Unfortunately, historical data concerning
students' programming proficiency is almost non-existent
and, at best, difficult to measure.  How then
might we approach solving this problem?
.A
Greene, I.
.I 596
.T
Floating-Point Arithmetic in COBOL
.W
In this paper the basic operations of floating-point
arithmetic are examined and COBOL procedures
for carrying these out are given, along with specification
of working storage.  The paper concludes with
an example in which these procedures are used.
.A
Kesner, O.
.I 597
.T
Modular Data Processing Systems Written in COBOL
.A
Emery, J. C.
.I 598
.T
The COBOL Librarian - A Key to Object Program Efficiency
.W
Many answers to the question "How may a COBOL
Compiler be forced into the generation of an
efficient object program?"  The purpose of this article
is to present one possible answer: the creation
and full utilization of a well-constructed COBOL Library.
.A
Hicks, W.
.I 599
.T
A Report Writer For COBOL
.A
Donally, W. L.
.I 600
.T
Syntactical Charts of COBOL 61
.A
Berman, R.
Sharp, J.
Sturges, L.
.I 601
.T
Interim Report on Bureau of Ships COBOL Evaluation Program
.A
Siegel, M.
Smith, A. E.
.I 602
.T
COBOL and Compatibility
.A
Lippitt, A.
.I 603
.T
Basic Elements of COBOL 61
.A
Sammet, J. E.
.I 604
.T
Why COBOL?
.A
Cunningham, J. F.
.I 605
.T
Computer Simulation Of City Traffic
.W
In simulating traffic flow on city streets,
the National Bureau of Standards has used data
processing techniques to tabulate and make motion pictures
of vehicle movements in the model.  Each vehicle
is assigned a digital identification giving points of
entry and exit, type of vehicle, desired speed,
and actual speed, in proportions simulating field data.
 Changes in the model can be made to observe
their consequences and to determine the ability of a
real street to carry loads expected in the future.
.I 606
.T
A Method for Eliminating Ambiguity Due
to Signal Coincidence in Digital Design
.A
Kaiser, C. J.
.I 607
.T
The Calculation of Easter...
.A
Knuth, D.
.I 608
.T
Permutation (Algorithm 71)
.A
Peck, J. E. L.
Schrack, G. F.
.I 609
.T
Permutation (Algorithm 71)
.A
Brown, P. J.
.I 610
.T
SIEVE (Algorithm 35)
.A
Brown, P. J.
.I 611
.T
Permutation Generator (Algorithm 87)
.A
Howell, J. R.
.I 612
.T
Permute (Algorithm 86)
.A
Peck, J. E. L.
Schrack, G. F.
.I 613
.T
JACOBI (Algorithm 85)
.A
Evans, T. G.
.I 614
.T
Simpson's Integration (Algorithm 84)
.A
Hennion, P. E.
.I 615
.T
Addressing Multidimensional Arrays
.W
A useful method of representing a function of
n variables is to consider the function to assume
its values at selected points in n-dimensional space.
 Although this picture is of value to the analyst,
the elements of an n-dimensional array must exist in
conventional storage as a linear array or vector.
 The means of performing the transformation of a set
of indices locating on array element in n-space
to the location (address) of the element in its storage
vector is the subject of this paper.  It is noted
that the index address transformation is computationally
identical to the conversion of a number from
a fixed to a mixed radix number system.  Several ways
of implementing the transformation are described.
.A
Hellerman, H.
.I 616
.T
An Information Algebra - Phase I Report-Language
Structure Group of the CODASYL Development Committee
.W
This report represents the results of the
first phase of the work of the Language Structure
Group.  The goal of this work is to arrive at a proper
structure for a machine-independent problem-defining
language, at the systems level of data processing.  The
report is based, for the most part, on a mathematical
model called "An Information Algebra" developed primarily
by R. Bosak.  It is hoped that this report
will be read (a) with avid interest by programming language
designers and implementors, and all those
interested in developing a theoretical approach to data
processing; (b) with interest and understanding
by professional programmers and systems analysts; and (c)
with appreciation by the businessman-analyst-manager.
 The authors have not attempted an exhaustive discourse
in this report.  Rather, they have tried to present
a philosophy to the professional people who are vitally
concerned with providing a working language for
the systems analyst's use.  They trust that the ideas
in this report will stimulate others to think along
similar lines.  Questions and comments will be welcomed,
and can be addressed to any of the members of
the Language Structure Group:  Robert Bosak, System
Development Corporation;  Richard F. Clippinger,
Honeywell EDP Division;  Carey Dobbs, Remington Rand
Univac Division;  Roy Goldfinger (Chairman), IBM
Corporation;  Renee B. Jasper, Navy Management Office;
 William Keating, National Cash Register;  George
Kendrick, General Electric Company;  Jean E. Sammet, IBM Corporation.
.I 617
.T
POSEIDON
.W
Any computer that forms part of a control system-whether
completely automatic or partly human-must
work at the same speed as the control system.  It must
perform its calculations or data processing fast
enough for the results to be available at the required
instants in the action of the control system.
 This known as working in "real time."
.A
Wheeling, R. F.
.I 618
.T
Computers- The Key to Total Systems Control: An Industrial Viewpoint
.W
Man-Man-machine processes are characterized in five
main types, and the markets for each type are
shown for 1950 and 1960 and estimated for 1970.
.A
Carlson, W. M.
.I 619
.T
Retrieval of Misspelled Names in an Airlines Passenger Record System
.W
This paper discusses the limited problem of
recognition and retrieval of a given misspelled
name from among a roster of several hundred names, such
as the reservation inventory for a given flight
of a large jet airliner.  A program has been developed
and operated on the Telefile (a stored-program
core and drum memory solid-state computer) which will
retrieve passengers' records successfully, despite
significant misspellings either at original entry time
or at retrieval time.  The procedure involves
an automatic scoring technique which matches the names
in a condensed form. Only those few names most
closely resembling the requested name, with their phone
numbers annexed, are presented for the agents
final manual selecton.  The program has successfully
isolated and retrieved names which were subjected
to a number of unusual (as well as usual) misspellings.
.A
Davidson, L.
.I 620
.T
RATFACT (Algorithm 78)
.A
Halstead, M. H.
.I 621
.T
Romberg Integration (Algorithm 60)
.A
Thacher Jr., H. C.
.I 622
.T
Optimal Classification of Objects (Algorithm 83)
.A
Mayoh, B. H.
.I 623
.T
Economising a Sequence 2 (Algorithm 82)
.A
Mayoh, B. H.
.I 624
.T
Economising a Sequence 1 (Algorithm 81)
.A
Mayoh, B. H.
.I 625
.T
Reciprocal Gamma Function of Real Argument (Algorithm 80)
.A
Holsten, W.
.I 626
.T
A Method of Representation, Storage and Retrieval
of 13 Random Codes in a 4-Digit Number or 16
Random Codes in a 5-Digit Number
.A
Foster, M. B.
.I 627
.T
Knotted List Structures
.A
Weizenbaum, J.
.I 628
.T
On a Floating-Point Number Representation
For Use with Algorithmic Languages
.A
Grau, A. A.
.I 629
.T
On a Wired-In Binary-to-Decimal Conversion Scheme
.A
Lynch, W. C.
.I 630
.T
An Evaluation of Autocode Readability
.W
Of the many requirements of an autocode, the
pair of requirements "easy to read" and "easy
to write" are not often compatible.  This paper argues
that readability can be added automatically in
the translation process so that the programmer can
enjoy the utmost economy of expression, while for
management a full and valid COBOL version is printed to give
all the advantages of readability and compatibility.
.A
Ellis, P. V.
.I 631
.T
Automatic-Programming-Language Translation Through Syntactical Analysis*
.A
Ledley, R.S.
Wilson, J. B.
.I 632
.T
Vectorcardiographic Diagnosis With The Aid of ALGOL
.A
Forsythe, G. E.
Von Der Groeben, J.
Toole, J. G.
.I 633
.T
Simulation and Analysis of Biochemical Systems
(III. Analysis and Pattern Recognition)
.A
Garfinkel, D.
Polk, W.
Higgins, J. J.
Ochser, R. T.
.I 634
.T
Manipulation of Trees in Information Retrieval*
.A
Salton, G.
.I 635
.T
A Note on Multiplying Boolean Matrices
.A
Baker, J. J.
.I 636
.T
Tape Splitting in an Iterative Program
.A
Weisert, C.
.I 637
.T
A NELIAC-Generated 7090-1401 Compiler
.W
NELIAC systems for several different machines
have been generated using the original NELIAC
system developed at the Naval Electronics Laboratory,
San Diego, in 1958.  A basic "bootstrap" process
was used to generate all but the first, i.e. the systems
were described in the NELIAC language and generated
by an existing NELIAC compiler.  This experience has
shown there is no inherent difficulty in "building
compilers with compilers"; indeed, it pointed out many advantages
in using a POL for constructing programming
systems.  This report presents the results of a project
completed in May, 1961 in which the NELIAC system
was used to generate a compiler for the IBM 1401.  The
1401 compiler, which runs on the 7090 and produces
1401 programs, was described in the NELIAC language and
generated with 7090 NELIAC system.  The reduction
in programming time and the improvement in documentation
of the system were very significant.
.A
Watt, J. B.
Wattenburg, W. H.
.I 638
.T
SURGE: A Recoding of the COBOL Merchandise Control Algorithm
.A
Longo, L. F.
.I 639
.T
Difference Expression Coefficients (Algorithm 79)
.A
Giammo, T. P.
.I 640
.T
Rational Roots of Polynomials with Integer Coefficients (Algorithm 78)
.A
Perry, C.
.I 641
.T
Interpolation, Differentiation, and Integration (Algorithm 77)
.A
Hennion, P. E.
.I 642
.T
An Introduction to ALGOL
.A
Schwarz, H. R.
.I 643
.T
Simulation and Analysis of Biochemcial Systems
(II. Solution of Differential Equations)
.A
Larson, R.
Sellers, P.
Meyer, R.
.I 644
.T
A String Language for Symbol Manipulation Based on ALGOL 60
.W
An artificial computer programming language
is proposed for describing the manipulation of
strings of characters and symbols.  The concept of strings,
introduced in the ALGOL 60 report, is extended
by adding: (1) the declaration of strings, substrings,
and string arrays with explicit lengths; (2) the
ability to concatenate and shift strings; and (3) the
ranking of symbols for comparing stings in Boolean
relations.  A primer or informal description of the
language is followed by examples, a description of
experiments with the language on an IBM 704 computer,
and a formal description which, taken with the
ALGOL 60 Report, defines the proposed string language.
.A
Wegstein, J. H.
Youden, W. W.
.I 645
.T
INVRS (Algorithm 66)
.A
Randell, B.
Broyden, C. G.
.I 646
.T
Inverse of a Finite Segment of the Hilbert Matrix (Algorithm 50)
.A
Randell, B.
.I 647
.T
Numerical Solution of the Polynomial Equation (Algorithm 30)
.A
Cohen, K. J.
.I 648
.T
Sorting Procedures (Algorithm 76)
.A
Flores, I.
.I 649
.T
FACTORS (Algorithm 75)
.A
Peck, J. E. L.
.I 650
.T
Curve Fitting with Constraints (Algorithm 74)
.A
Peck, J. E. L.
.I 651
.T
A Survey of Languages and Systems for Information Retrieval
.A
Grems, M.
.I 652
.T
Use of Semantic Structure in Information Systems
.A
Sable, J. D.
.I 653
.T
Translation of Retrieval Requests Couched
in a "Semiformal" English-Like Language*
.A
Cheatham Jr., T. E.
Warshall, S.
.I 654
.T
Language Problems Posed by Heavily Structured Data
.A
Barnes, R. F.
.I 655
.T
COMIT as an IR Language
.W
Many of the features that make COMIT a good
all around symbol manipulation language also render
it well suited to various types of information retrieval
programs.  Presented here is a general discussion
of this unique and different programming language
and an examination of some of its applications.
.A
Yngve, V. H.
.I 656
.T
An Information System With The Ability To Extract Intelligence From Data
.A
Wang, T. L.
.I 657
.T
Information Structures for Processing and Retrieving
.A
Colilla, R. A.
Sams, B. H.
.I 658
.T
Discussion-The Pros and Cons of a Special IR Language
.A
Sammet, J. E.
Ohlman, H.
Bohnest, H. G.
.I 659
.T
Reversion of Series (Algorithm 193)
.A
Thacher Jr., H. C.
.I 660
.T
More Test Matrices for Determinants and Inverses (Pracnique)
.A
Englar, T. S.
.I 661
.T
Indexing and the Lambda-Notation
.W
Some methods of indexing sequentially stored
elements of sparse multi-dimensional arrays are
described in the scheme A notation.
.A
Barnett, M. P.
.I 662
.T
Shuttle Sort (Algorithm 175)
.A
Juelich, O. C.
.I 663
.T
Determinant (Algorithm 159)
.A
Lapidus, A.
.I 664
.T
Assignment (Algorithm 27)
.A
Witty, R. D.
.I 665
.T
Gauss-Seidel (Algorithm 220)
.A
Shantz, P. W.
.I 666
.T
Topological Ordering for Pert Networks (Algorithm 219)
.A
Kase, R. H.
.I 667
.T
Kutta Merson (Algorithm 218)
.A
Lukehart, P. M.
.I 668
.T
Minimum Excess Cost Curve (Algorithm 217)
.A
Briggs, W. A.
.I 669
.T
A Specification of JOVIAL
.A
Shaw, C. J.
.I 670
.T
Some Legal Implications of the Use of Computers in the Banking Business
.W
The introduction of computers in to the banking
business has a wide variety of legal implications
that merit careful attention at this very early stage.
 The industry is highly regulated by government
and, hence, is subject to many statutes and regulations.
 It also is affected by important common law
rules established by courts.  The legal ramifications
involve not only the mechanization itself, but
also the very significant, economically attractive phenomenon
of off premises processing.  It is essential
to identify and provide for many legal aspects right
now, before systems and practices crystallize, in
order to avoid the later impact of unanticipated physical
complications and expense.  The legal aspects
of computerization in the banking business are especially
diverse.  In some states, there might be the
basic question whether banks are authorized by law to
invest in the new facilities, either directly or
through cooperatives.  More challenging are questions
relating to off-premises processors, particularly
with respect to the obligation not to disclose information
concerning a bank's customers, the adequacy
of fidelity bond coverage, the extent of liability for
improper refusal to pay a check, and susceptibility
to regulation by government agencies.  Also pertinent
is the propriety of data processing by banks for
nonbank entities and particularly of the rendering of
that service without charge for bank depositors.
.A
Freed, R. N.
.I 671
.T
TELEFILE-A Case Study of an On-Line Savings Bank Application
.W
The development of an on-line computer system
for a savings bank institution is traced from
the early conceptual needs of the bank to the consummation
of design by The Teleregister Corporation.
 Both bank and equipment criteria are specified which
led to the development of the Telefile System of
The Teleregister Corporation.  Operation of the on-line
and off-line programs are described and statistics
are cited for reliability and performance of the system.
 Benefits to the bank are discussed from the
banker's point of view; an indication of future trends
in the on-line savings bank field is also discussed.
.A
Sanders, M.
.I 672
.T
Recent Developments Affecting ADP in Tax Administration
.A
Leibowitz, G. J.
.I 673
.T
Account Classification at Automating Banks
.A
Eckert, J. B.
.I 674
.T
Application of IBM 1620 EDP Methods to the Calculation
of the Formation Constants of Complex
Irons
.A
Andrews, A. C.
Hassler, J.
DeCou, F.
.I 675
.T
Coding Clinical Laboratory Data For Automatic Storage and Retrieval
.W
A series of clinical laboratory codes have been
developed to accept and store urin analysis, blood
chemistry, and hematology test results for automatic
data processing.  The codes, although constructed
as part of a computerized hospital simulation, have been
able to handle the results of every laboratory
test that they have encountered.  The unique feature of
these codes is that they can accept conventionally
recorded qualitative as well as quantitative test results.
 Consequently, clinical test results need
not be arbitrarily stratified, standardized, or altered
in any way to be coded.  This paper describes
how the codes were developed and presents a listing of the
urin analysis codes.  Five criteria used in developing
the codes are outlined and the problem of multiple-synonymous
terminology is discussed.  A solution to
the problem is described.  Flexible, computer-produced,
composite laboratory reports are also discussed,
along with reproduction of such a report. The paper concludes
that even though many problems remain unsolved,
the next ten years could witness the emergence of a practical
automated information system in the laboratory.
.A
Gross, L. D.
.I 676
.T
On the Computation of a Certain Type of IncompleteBeta Functions
.A
Tang, I. C.
.I 677
.T
Length of Strings for a Merge Sort
.W
Detailed statistics are given on the length
of maximal sorted strings which result form the
first (internal sort) phase of a merge sort onto tapes.
 It is shown that the strings produced by an
alternating method (i.e. one which produces ascending
and descending strings alternately) tend to be
only three-fourths as long as those in a method which produces
only ascending strings, contrary to statements
which have appeared previously in the literature.  A
slight modification of the read-backward polyphase
merge algorithm is therefore suggested.
.A
Knuth, D. E.
.I 678
.T
Optimizing Bit-time Computer Simulation
.W
A major component of a bit-time computer simulation
program is the Boolean compiler.  The compiler
accepts the Boolean functions representing the simulated computer's
digital circuits, and generates corresponding
sets of machine instructions which are subsequently
executed on the "host" computer.  Techniques are
discussed for increasing the sophistication of the Boolean
compiler so as to optimize bit-time computer
simulation.  The techniques are applicable to any general-purpose computer.
.A
Katz,J. H.
.I 679
.T
Recent Improvements in MADCAP
.W
MADCAP is a programming language admitting subscripts,
superscripts and certain forms of displayed
formulas.  The basic implementation of this language was
described in a previous paper [MADCAP: A scientific
compiler for a displayed formula textbook language, Comm.
ACM 4 (Jan. 61), 31-36].  This paper discusses
recent improvements in the language in three areas: complex
display, logical control, and subprogramming.
 In the area of complex display, the most prominent improvements
are a notation for integration and for
the binomial coefficients.  In the area of logical control
the chief new feature is a notation for variably
nested looping.  The discussion of subprogramming is focused
on MADCAP's notation for and use of "procedures."
.A
Wells, M. B.
.I 680
.T
An Error-Correcting Parse Algorithm
.A
Irons, E. T.
.I 681
.T
Flexible Abbreviation of Words in a Computer Language
.A
Lomis, R. G.
Rubin, J.
.I 682
.T
Recursive programming in FORTRAN II
.A
Ayers, J. A.
.I 683
.T
A Serial Technique to Determine Minimum Paths
.A
Weimer, D. L.
.I 684
.T
Interpolation, Differentiation, and Integration (Algorithm 77)
.A
Hennion, P. E.
.I 685
.T
Euler Summation (Algorithm 8)
.A
Thacher Jr., H. C.
.I 686
.T
Smooth (Algorithm 216)
.A
George, R.
.I 687
.T
Shanks (Algorithm 215)
.A
Thacher Jr., H. C.
.I 688
.T
q-Bessel Functions In(t)(Algorithm 214)
.A
Simoes Pereira, J. M. S.
.I 689
.T
Report of a Visit to Discuss Common Programming
Languages in Czechoslovakia and Poland, 1963
.A
Gosden, J. A.
Merner, J. N.
Gay, R. E.
Jones, J. L.
Christopher, J. S.
.I 690
.T
USA Participation in an International
Standard glossary on Information Processing
.A
Traub, J. F.
.I 691
.T
A Description of the APT Language
.W
The APT (Automatically Programmed Tools) language
for numerical control programming is described
using the metalinguistic notation introduced in the ALGOL
60 report.  Examples of APT usage are included.
 Presented also are an historical summary of the development
of APT and a statement concerning its present
status.
.A
Brown, S. A.
Drayton, C. E.
Mittman, B.
.I 692
.T
On the Inverse of a Test Matrix
.A
Stockmal, F. J.
.I 693
.T
An Extension of Fibonaccian Search To Several Variables
.W
A technique which uses Fibonaccian search
concepts has been developed to solve optimization
problems involving unimodal functions of several variables.
 The technique has not been proven to be
optimal in the sense that the one-dimensional Fibonaccian
search is.  However, it is valuable for certain
kinds of calculations.
.A
Krolak, P.
Cooper, L.
.I 694
.T
A Comparison of Disks and Tapes
.W
The principal characteristics of current magnetic
disks and tape units are summarized and compared.
 Some of the characteristics of disk files are illustrated
in a sorting example and compared to a tapesort.
 The conclusion is presented that disk files are competitive
to tapes in some important applications.
.A
Hess, H.
.I 695
.T
Use of the Disk File on Stretch
.W
The paper begins by briefly describing the
Stretch (IBM 7030) computer with special emphasis
given to the organization and operation of its input-output
equipment.  Physical characteristics of the
two-disk system (4,194,304 72-bit words, 8 usec-per-word
transmission rate, etc.) are noted.  Timing
limitations due to arm motion and disk rotation are discussed.
 Applications of disk usage are discussed
separately for problem programs and for systems programs
such as compilers and the supervisory program.
Approximately 260,000 words of disk storage are reserved
for the storage of systems programs and the
subroutine library.  Problem programs, however, are not
currently filed on the disk.  Certain programming
techniques are discussed for transmitting words between
disk and core storage with minimum delaying and
interruption of the arithmetic unit.  Dumps on disk are
considered for both recovery from computer malfunction
and for mathematical or physical developments during
the calculation.  Some comments are made regarding
the reliability, economics, utility and weaknesses or
limitations of the disk system.  Several possible
future applications are noted which appear to have disk connotations.
.A
Carlson, B. G.
Voorhes, E. A.
.I 696
.T
An Automatic Data Acquisition and Inquiry System Using Disk Files
.W
Lockheed Missiles and Space Company has installed
a large-scale Automatic Data Acquisition
(ADA) system which ties together the Company's manufacturing
facilities located in Van Nuys and Sunnyvale,
California.  The system includes over 200 remote Input
Stations which collect and transmit Company operating
data to a central Data Processing Center.  Two RCA 301
EDP Systems are used to record and control the
flow of data transmitted to the Data Processing Center.
 A large capacity RCA 366 Data Disc File is used
to store information required to provide up-to-date
information in response to inquiries received from
remotely located Inquiry Stations.  In addition to storage
of data on the disk files, the system automatically
records all incoming and outgoing data on magnetic tape
to be used as input to the Company's conventional
off-line business data processing applications.
.A
Edwards, J. D.
.I 697
.T
A Numerical Method for the Determination of Moving
Field Isodose Curves for Treatment Planning
in Radiotherapy
.A
Dalrymple, G. V.
Perez-Tamayo, R.
.I 698
.T
DATA-DIAL: Two-Way Communication with
Computers From Ordinary dial Telephones
.W
An operating system is described which allows
users to call up a remotely located computer
from ordinary dial telephones.  No special hardware or
connections are required at the users' telephones.
 Input to the computer is through the telephone dial;output
from the computer is in spoken form.  Results
of a test with telephones in the Boston area are reported.
.A
Marill, T.
Edwards, D.
Feurzeig, W.
.I 699
.T
A Contour-Map Program for X-Ray Crystallography
.W
A FORTRAN program is described for use with
the IBM 7090 system and an X, Y-plotter to produce
a contour map.  A matrix of points evenly spaced in
each dimension is contoured.  Scale factors along
the axes may be different and the axes need not be perpendicular.
.A
Dayhoff, M. O.
.I 700
.T
Hermite Interpolation (Algorithm 210)
.A
Dwyer, T. A.
.I 701
.T
Shuttle Sort (Algorithm 175)
.A
Schubert, G. R.
.I 702
.T
Assign (Algorithm 173)
.A
Filsak, Z.
Vrchovecka, L.
.I 703
.T
Assign (Algorithm 173)
.A
Scowen, R. S.
.I 704
.T
Combinatorial of M Things Taken One At A Time
Two At A Time, Up To N At A Time (Algorithm 161)
.A
Collins, D. H.
.I 705
.T
Combinatorial Of M Things Taken N At A Time (Algorithm 160)
.A
Blakely, R. E.
.I 706
.T
Fourier Series Approximation (Algorithm 157)
.A
Schubert, G. R.
.I 707
.T
Erf(x) (Algorithm 123)
.A
Ibbetson, D.
.I 708
.T
Evaluation of the Fresnel Integrals (Algorithm 88, 89, 90)
.A
Gray, M. D.
.I 709
.T
Assignment (Algorithm 27)
.A
Newhouse, A.
.I 710
.T
Fresnel Integrals (Algorithm 213)
.A
Gray, M. D.
.I 711
.T
Frequency Distribution (Algorithm 212)
.A
Gray, M. D.
.I 712
.T
Hermite Interpolation (Algorithm 211)
.A
Schubert, G. R.
.I 713
.T
Lagrangian Interpolation (Algorithm 210)
.A
Schubert, G. R.
.I 714
.T
Gauss (Algorithm 209)
.A
Ibbetson, D.
.I 715
.T
Discrete Convolution (Algorithm 208)
.A
Foreman Jr., W. T.
.I 716
.T
Stringsort (Algorithm 207)
.A
Boothroyd, J.
.I 717
.T
Partitioning Algorithms for Finite Sets
.W
The partitions of a set with n elements are represented
by certain n-tuples of positive integers.
 Algorithm are described which generate without repetitions
the n-tuples corresponding to: (1) all partitions
of the given set, (2) all partitions of the given set
into m or fewer sets (1 <= m <= n), and (3) all
partitions of the given set into exactly m sets (1 <= m <= n).
.A
Hutchinson, G.
.I 718
.T
An Experiment in Automatic Verification of Programs
.W
How effective is a compiler at replacing explicit
verification, and what is the cost of this
technique?
.A
Weinberg, G. M.
Gressett, G. L.
.I 719
.T
Variable Width Stacks
.W
Character addressable, variable field computers
permit ready establishment and manipulation
of variable width stacks.  Single machine commands may
push variable field items down into such stacks
or pop them up.  The availability of a variety of field
delimiters allows the machine to push down or
pop up more than one variable width item with one command.
 Since these stacking operations can be made
the basis of compiler decoding algorithms the proper
use of machines of this class for compilation has
advantages over machines with fixed-length words.
.A
Rotenberg, N.
Opler, A.
.I 720
.T
Format-Free Input in FORTRAN
.A
Bailey, M. J.
Barnett, M. P.
Futrelle, R. P.
.I 721
.T
Report on Proposed American Standard Flowchart
Symbols for Information Processing
.W
This paper presents the essential contents of
the Proposed American Standard Flowchart Symbols
for Information Processing.  This is the first proposed
standard prepared by Subcommittee X3.6 on Problem
Description and Analysis of the American Standards Association (ASA).
.A
 Rossheim, R. J.
.I 722
.T
ALCOR Group Representation of ALGOL Symbols
.I 723
.T
ECMA Subset of ALGOL 60
.I 724
.T
A Profile of the Programmer
.W
Synopsis: 549 members of the ACM participated
in a study concerned primarily with the attitudes
of programmers toward their careers and jobs.  A very
high percentage of programmers have apparently
entered their careers by accident; it has proven a happy
choice for most and they expect to remain in
the field during the next five years.  Their principal
job satisfactions relate to the nature of their
work, and mostfind their jobs offer high level of professional
interest and good working conditions.
 Salary and advancement prospects, however,are not as
satisfactory.  More than half report a positive
attitude toward programmers and programming on the part
of their organizations.  Turnover among themselves
is attributed primarily to poor management-salary is
seen as the principal motivating factor in turnover
among other programmers.  Nature of the work offered
and salary are principal determinants in accepting
a new job.  Programmers are less mobile than expected.
 Programmers tend to see their colleagues in a
favorable light, on the whole.  Personalities seem to
vary with function, systems programmers differing
from applications programmers.  Four principal problems
for programming in the immediate future are listed
by participants: languages, personnel, various specific
applications and techniques, and building programming
as a profession.
.I 725
.T
Group Participation Computer Demonstration
.A
McCormick, E. M.
.I 726
.T
A General Program for the Analysis of
Square and Rectangular Lattice Designs
.W
This paper describes a general-purpose program
that will handle those incomplete block designs
known as square and rectangular lattices.  Flow diagrams
are given so that the method of calculation
may be programmed for any digital computer.
.A
Smillie, K. W.
.I 727
.T
On the Approximate Solution of Delta(u)=F(u)
.W
Three-dimensional Dirichlet problems for Delta(u)=F(u),
Fu >= 0, are treated numerically by
an exceptionally fast, exceptionally accurate numerical
method.  Programming details, numerous examples
and mathematical theory are supplied.Extension of the
method in a natural way to n-dimensional problems
is indicated by means of a 4-dimensional example.
.A
Greenspan, D.
Yohe, M.
.I 728
.T
Computer-Drawn Flowcharts*
.W
To meet the need for improved documentation
of written computer programs, a simple system for
effective communication is presented, which has shown
great promise.  The programmer describes his program
in a simple format, and the computer prepares flow charts
and other cross-referenced listings from this
input.  The description can be kept up-to-date easily,
and the final output clearly explains the original
program.  The system has also proved to be a valuable debugging and coding aid.
.A
Knuth, D. E.
.I 729
.T
A Generalization of ALGOL
.A
Wirth, N.
.I 730
.T
MIRFAG: A Compiler Based on Standard
Mathematical Notation And Plain English
.W
A pilot version of the compiler MIRFAG, now
in operation, is described.  The chief features
of the system, which is intended for the solution of scientific
problems, are the presentation of mathematical
formulas entirely in standard textbook notation.  The use
of plain English for organizational instructions,
automatic error diagnosis indicating the actual location
of the error in the uncompiled program, and
an attempt to minimize that fragmentation of the original
problem statement which is a normal feature
of programming systems.
.A
Gawlik, H. J.
.I 731
.T
Symmetric List Processor
.W
A list processing system in which each list
cell contains both a forward and a backward link
as well as a datum is described.  This system is intended
for imbeding in higher level languages capable
of calling functions and subroutines coded in machine language.
 The presentation is in the form of FORTRAN
programs depending on only a limited set of FORTRAN programs
depending on only a limited set of "primitive"
machine language subroutines which are also defined.
 Finally, a set of field, particularly character,
manipulation primitives are given to round out the system.
.A
Weizenbaum, J.
.I 732
.T
Monte Carlo Inverse (Algorithm 166)
.A
Rodman,R. D.
.I 733
.T
Newton Interpolation with Forward Divided Differences (Algorithm 169)
.A
Thacher Jr., H. C.
.I 734
.T
Newton Interpolation with Backward Divided Differences (Algorithm 168)
.A
Thacher Jr., H. C.
.I 735
.T
Calculation of Confluent Divided Differences (Algorithm 167)
.A
Thacher Jr., H. C.
.I 736
.T
Modified Hankel Functions (Algorithm 163)
.A
Thacher Jr.,H. C.
.I 737
.T
Exponentiation of Series (Algorithm 158)
.A
Lawrence, J. D.
.I 738
.T
Fourier Series Approximation (Algorithm 157)
.A
George, R.
.I 739
.T
MINIFUN (Algorithm 129)
.A
Wasscher, E. J.
.I 740
.T
INTEREST (Algorithm 45)
.A
Wright, C. B.
.I 741
.T
Evaluation of Determinant (Algorithm 41)
.A
Freed, B. H.
.I 742
.T
Evaluation of Determinant (Algorithm 41)
.A
Freed, B. H.
.I 743
.T
ARCCOSIN (Algorithm 206)
.A
Konda, M.
.I 744
.T
ATIVE (Algorithm 205)
.A
Haubrich, J. G. A.
.I 745
.T
STEEP2 (Algorithm 204)
.A
Wasscher, E. J.
.I 746
.T
STEEP1 (Algorithm 203)
.A
Wasscher, E. J.
.I 747
.T
Generation of Permutations in Lexicographical Order (Algorithm 202)
.A
Shen, M. K.
.I 748
.T
A Semi-Iterative Process for Evaluating Arctangents
.A
Chu, W. H.
Saathoff, D. R.
.I 749
.T
Note onStochastic Matrices
.A
Dumey, A. I.
.I 750
.T
PEI Matrix Eigenvectors
.A
Newbery, A. C. R.
.I 751
.T
A Note on a Set of Test Matrices for Inversion
.A
Rodman, R. D.
.I 752
.T
Closing Out a Print Tape
.A
Moore, D. P.
.I 753
.T
A Procedure for Converting Logic Table Conditions
into an Efficient Sequence of Test Instructions
.A
Egler, J. F.
.I 754
.T
Ye Indiscreet Monitor
.A
Blatt, J. M.
.I 755
.T
An Exponential Method of Numerical Integration
of Ordinary Differential Equations
.W
A formula for numerical integration is prepared,
which involves an exponential term.  This
formula is compared to two standard integration methods,
and it is shown that for a large class of differential
equations, the exponential formula has superior stability
properties for large step sizes.  Thus this
formula may be used with a large step size to decrease the
total computing time for a solution significantly,
particularly in those engineering problems where high accuracy is not needed.
.A
Pope, D. A.
.I 756
.T
A Computer Program for Editing the News
.A
Danielson, W. A.
Briggs, B.
.I 757
.T
Simulation of a Traffic Network
.A
Katz, J. H.
.I 758
.T
Skeletal Structure of PERT and CPA Computer Programs
.W
An introduction to the inner mechanics of
PERT and CPA computer programs is provided.  The
major components of these programs as well as their
purposes and interrelationships are outlined.
.A
Kahn, A. B.
.I 759
.T
Continued Operation Notation for Symbol
Manipulation and Array Processing
.W
A brief account is given of a notational device
that is very useful in the formal representation
of syntaxes, string relationships and string transformation
procedures and also of computing procedures
that deal with arrays of functions of many variables.
The device consists of the use of certain "continued
operation" or "collective" symbols that are analogous to the summation
symbol (Sigma) and continued multiplication
symbol (Pi) of conventional mathematics.
.A
Barnett, M. P.
.I 760
.T
Dialects of FORTRAN
.A
Pyle, I. C.
.I 761
.T
A Note on the Dangling Else in ALGOL 60
.W
Some revisions of ALGOL 60 are proposed, which
not only eliminate certain ambiguous statements
but also add some convenience to the language.  A discussion
of the background of the problem and a sketch
of a proof that the ambiguities have been removed is included.
.A
Kaupe Jr., A. F.
.I 762
.T
Some Remarks on the Syntax of Symbolic Programming Languages
.A
DiForino, A. C.
.I 763
.T
A Syntax Controlled Generator of Formal Language Processors
.A
Eickel, J.
Bauer, F. L.
Paul, M.
Samelson, K.
.I 764
.T
Reduction of a Matrix Containing Polynomial Elements (Algorithm 170)
.A
Hennion, P. E.
.I 765
.T
Orthogonal Polynomial Least Squares Surface Fit (Algorithm 164)
.A
Bitterli, C. V.
.I 766
.T
XY-move Plotting (Algorithm 162)
.A
Fletcher, W. E.
.I 767
.T
Certification of Algorithm 161
Combinatorial of M Things Taken One at a Time,
Two at a Time, Up to N at a Time
[M. L. Wolfson and H. V. Wright,
Comm. ACM, Apr. 1963]
.A
Thoro, D.
.I 768
.T
Certification of Algorithm 160
Combinatorial of M Things Taken N at a Time [M. L. Wolfson and H. V. Wright,
Comm. ACM, Apr. 1963]
.A
Thoro, D.
.I 769
.T
Algebra of Sets (Algorithm 156)
.A
Bosworth, K. M.
.I 770
.T
Combination in Any Order (Algorithm 155)
.A
Bosworth, K. M.
.I 771
.T
Combination in Lexicographical Order (Algorithm 154)
.A
Bosworth, K. M.
.I 772
.T
GOMORY (Algorithm 153)
.A
Lefkowitz, B.
D'Esopo, D. A.
.I 773
.T
Matrix Inversion (Algorithm 140)
.A
George, R.
.I 774
.T
Jacobi (Algorithm 85)
.A
Naur, P.
.I 775
.T
Interpolation, Differentiation, and Integration (Algorithm 77)
.A
Hennion, P. E.
.I 776
.T
Partition, Quicksort, and Find (Algorithm 62, 64, & 65)
.A
Randell, B.
Russell, L. J.
.I 777
.T
A Set of Test Matrices (Algorithm 52)
.A
Naur, P.
.I 778
.T
Associated Legendre Functions of the First Kind
for Real or Imaginary Arguments (Algorithm 47)
.A
George, R.
.I 779
.T
CROUT II (Algorithm 43)
.A
Domingo, C.
Rodriguez-Gil, F.
.I 780
.T
Algorithm 42 INVERT, Alg.107 Gauss's
Method, Alg.120 Inversion II, and gjr
.A
Naur, P.
.I 781
.T
Telescope 2 (Algorithm 38)
.A
Bridges, J. F.
.I 782
.T
Telescope 1 (Algorithm 37)
.A
Bridges, J. F.
.I 783
.T
Shellsort (Algorithm 201)
.A
Boothroyd, J.
.I 784
.T
Normal Random (Algorithm 200)
.A
George, R.
.I 785
.T
Conversions Between Calendar Date And Julian day Number (Algorithm 199)
.A
Tantzen, R. G.
.I 786
.T
Adaptive Integration and Multiple Integration (Algorithm 198)
.A
McKeeman, W. M.
.I 787
.T
Matrix Division (Algorithm 197)
.A
Wells, M.
.I 788
.T
Muller's Method for Finding Roots of
an Arbitrary Function (Algorithm 196)
.A
Roman, R. D.
.I 789
.T
Bandsolve (Algorithm 195)
.A
Thurnau, D. H.
.I 790
.T
Zersol (Algorithm 194)
.A
Domingo, C.
.I 791
.T
Character Manipulation in 7090 Fortran
.A
Smith, D. D.
.I 792
.T
Multiple-Precision Binary-To-Decimal Integer
Conversion Using Only Addition And Subtraction
.A
Keyes, D. F.
Moore, D. P.
.I 793
.T
Mapped List Structures
.A
Baecker, H. D.
.I 794
.T
A List-Type Storage Technique for Alphameric Information
.W
A method which is economic in terms of space and
time is proposed for the storage and manipulation
of character strings of arbitrary length in a fixed
word-length computer.  The method is illustrated
in an application to Algol-type identifiers in an Algol-like block structure.
.A
Bowlden, H. J.
.I 795
.T
Debugging Systems at the Source Language Level
.A
Ferguson, H. E.
Berner, E.
.I 796
.T
SABRAG, A Time-Sharing Low-Cost Computer
.W
The serial SABRAC computer designed and built
in the Scientific Department of the Israel defense
Ministry has a 5000-location magnetic drum, main store.
 To avoid a need to resort to optimum programming
techniques and to increase its overall efficiency the
computer has also been given a 224-word ferrite
core store from which the program is obeyed.  Transfers
between the core and drum stores and to and from
the twin paper-tape input and output channels are all
available autonomously (concurrently, time-shared).
 Multiplication and division orders are also autonomous,
so that the machine may be executing up to three
orders simultaneously.  All functions naturally are interlocked.
 A number of other advanced orders and
facilities are also incorporated.In particular, an
"Execute" order permits a temporary jump for up
to four orders and a second modifier register permits double
modification in general and relative addressing
of subroutines in particular.  Thus the overall effective
speed of the machine is muchhigher than its
basic specification would lead one to expect and its
design indicates one way in which the concepts of
time sharing may be incorporated in "low-cost" computers.
.A
Lehman, M.
Netter, Z.
Eshed, R.
.I 797
.T
American Standard Code for Information Interchange
.I 798
.T
A Catalogue Entry Retrieval System
.A
Scheff, B. H.
.I 799
.T
Design of a Separable Transition-Diagram Compiler*
.W
A COBOL compiler design is presented which is
compact enough to permit rapid, one-pass compilation
of a large subset of COBOL on a moderately large computer.
 Versions of the same compiler for smaller
machines require only two working tapes plus a compiler
tape.  The methods given are largely applicable
to the construction of ALGOL compilers.
.A
Conway, M. E.
.I 800
.T
The Linking Segment Subprogram Language and Linking Loader
.A
McCarthy, J.
Corbato, F. J.
Daggett, M. M.
.I 801
.T
Least Squares Solution with Constraints (Algorithm 177)
.A
Synge, M. J.
.I 802
.T
SYMINV2 (Algorithm 150)
.A
Rutishauser, H.
.I 803
.T
Syminv2 (Algorithm 150)
.A
Evans Jr., A.
.I 804
.T
Exponentiation of Series (Algorithms 134)
.A
Thacher Jr., H. C.
.I 805
.T
Newton Maehly (Algorithm 105)
.A
Kondo, J.
.I 806
.T
Remark on Certification of Matrix Inversion Procedures
.A
Moler, C.
.I 807
.T
Reversion of Series (Algorithm 193)
.A
Fettis, H. E.
.I 808
.T
Confluent Hypergeometric (Algorithm 192)
.A
Relph, A. P.
.I 809
.T
Hypergeometric (Algorithm 191)
.A
Relph, A. P.
.I 810
.T
Complex Power (Algorithm 190)
.A
Relph, A. P.
.I 811
.T
Smoothing 2 (Algorithm 189)
.A
Rodriguez Gil, F.
.I 812
.T
Smoothing 1 (Algorithm 188)
.A
Rodriguez-Gil, F.
.I 813
.T
Differences and Derivatives (Algorithm 187)
.A
Vande Riet, R. P.
.I 814
.T
Complex Arithmetic (Algorithm 186)
.A
Vande Riet, R. P.
.I 815
.T
Normal Probability for Curve Fitting (Algorithm 185)
.A
Colker, A.
.I 816
.T
Erlang Probability for Curve Fitting (Algorithm 184)
.A
Colker, A.
.I 817
.T
Nexcom (Algorithm 152)
.A
Hopley, J.
.I 818
.T
Realizing Boolean Connectives on The IBM 1620
.A
Hellerman, H.
Senzig, D. N.
.I 819
.T
Polynomial Evaluation Revised
.A
Eisman, S. H.
.I 820
.T
Checking for Loops in Networks
.A
Gordon, R. M.
.I 821
.T
Further Remarks on Sampling a Tape File-III
.A
Juelich, O. C.
.I 822
.T
Real-Time Programming Specifications
.W
Problems in the implementation of large real-time
applications are treated, and suggested guidelines
for both program and file specifications are developed.
 The problems delineated also occur in systems
programming.
.A
Head, R. V.
.I 823
.T
A Syntactic Description of BC NELLIAC
.A
Huskey, H. D.
Love, R.
Wirth, N.
.I 824
.T
DESCRIPTRAN-Automated Descriptive Geometry*
.W
Descriptive geometry consists of procedures originally
designed to solve 3-space geometry problems
by graphical constructions and measurement instead of
by computation.  However, in addition to this it
unifies and simplifies the approach to many such problems.
 When one can call subroutines that compute
new coordinates that correspond to those obtainable from
the graphical constructions, there is the three-way
advantage of the approach of descriptive geometry, the
accuracy of computation and the speed of the digital
computer.  DESCRIPTRAN makes it possible to program
many problems in 3-space with a few statements; it
consists of 15 subroutines analogous to the procedures of descriptive geometry.
.A
Kliphardt, R. A.
.I 825
.T
PIP: A Photo-Interpretive Program
for the Analysis of Spark-Chamber Data*
.W
An operating computer program that processes
photographically recorded data is described.
The input to the program consists of spark-chamber photographs
on which tracks of high-energy particles
are recorded.  The program automatically scans, measures
and performs the preliminary interpretation
of these photographs.  In continuous operation a processing
rate of 5,000 photographic frames per hour
is achieved.
.A
Rudloe, H.
Deutsch, M.
Marill, T.
.I 826
.T
Remarks on Fortran Subroutines for Time Series Analysis
.A
Bennett, C. M.
.I 827
.T
Disk File Sorting
.W
Sorting techniques using an IBM 1401 with
a random access storage device are evaluated.
.A
Schick, T.
.I 828
.T
Incompressible flow Network Calculations
.W
A general method for the calculation of flows
and pressures in fluid flow networks is presented.
 The method is applicable to computer use.
.A
Cantrell, H. N.
.I 829
.T
The External Language KLIPA For the URAL-2 Digital computer
.A
Greniewski, M,
Turski, W.
.I 830
.T
CORC-The Cornell Computing Language
.A
Conway, R. W.
Maxwell, W. L.
.I 831
.T
Real Error Function, ERF (Algorithm 123)
.A
Thacher Jr., H. C.
.I 832
.T
Curve Fitting with Constraints (Algorithm 74)
.A
Isoda, K.
.I 833
.T
Reduction of a Symmetric Bandmatrix to Triple Diagonal Form
.A
Schwartz, H. R.
.I 834
.T
Nonrecursive Adaptive Integration (Algorithm 182)
.A
McKeeman, W. M.
Tesler, L.
.I 835
.T
Complementary Error Function-Large X (Algorithm 181)
.A
Thacher Jr., H. C.
.I 836
.T
Error Function-Large X (Algorithm 180)
.A
Thacher Jr., H. C.
.I 837
.T
Incomplete Beta Ratio (Algorithm 179)
.A
Ludwig, O. G.
.I 838
.T
Direct Search (Algorithm 178)
.A
Kaupe Jr., A. F.
.I 839
.T
Least Squares Solution with Constraints (Algorithm 177)
.A
Synge, M. J.
.I 840
.T
Least Squares Surface Fit (Algorithm 176)
.A
Arthurs, T. D.
.I 841
.T
Shuttle Sort (Algorithm 175)
.A
Shaw, C. J.
Trimble, T. N.
.I 842
.T
A Posteriori Bounds on a Zero of a Polynomial (Algorithm 174)
.A
Gibb, A.
.I 843
.T
Assign (Algorithm 173)
.A
Hajek, O.
.I 844
.T
1410 Fortran Edit Feature
.A
Fedako,J. E.
.I 845
.T
Another Test Matrix for Determinants and Inverses
.A
Caffrey, J.
.I 846
.T
Self-Inverse Conversion Table
.A
Sanborn, T. G.
.I 847
.T
A Penny-Matching Program
.W
The logic of a penny-matching program
written for the CSX-1 is described.
.A
Wall, E.
Brown, R. M.
.I 848
.T
A Note on Range Transformations for Square Root and Logarithm
.W
There was the germ of an idea in two previous
papers [1,2] which no one seems to have picked
up in almost five years.  For certain functions it seems
desirable to transform the argument to a short
range symmetric about 10.1 will give examples of this
usage for the square root and logarithm function
for both binary and decimal machines.
.A
Bemer, R. W.
.I 849
.T
Use of Tree Structures for Processing Files
.W
In data processing problems, files are frequently
used which must both be searched and altered.
 Binary search techniques are efficient for searching
large files, but the associated file organization
is not readily adapted to the file alterations.  Conversely,
a chained file allocation permits efficient
alteration but cannot be searched efficiently. A file
organized into a tree-like structure is discussed,
and it is shown that such a file may both be searched
and altered with times proportional to slog(s)N,
where N is the number of file items and s is a parameter
of the tree.  It is also shown that optimizing
the value of s leads to a search time which is only 25
per cent slower than the binary search.  The tree
organization employs two data chains and may be considered
to be a compromise between the organizations
for the binary search and the chained file.  The relation
of the tree organization to multidimensional
indexing and to the trie structure is also discussed.
.A
Sussenguth Jr., E. H.
.I 850
.T
Conversion, Reconversion and Comparison
Techniques In Variable-Length Sorting
.W
The logic is described for converting highly
variable input records into a format that can
be easily and efficiently processed by a sorting program.
 The internal record formats are discussed
in relation to (1) their conversion from input formats,
(2) their reconversion to output formats, and
(3) comparison techniques between internal formats.
.A
Waks, D. J.
.I 851
.T
Design and Characteristics of a Variable-Length
Record Sort Using New Fixed-Length Record Sorting
Techniques
.W
This paper describes the application of several
new techniques for sorting fixed-length records
to the problems of variable-length record sorting.
The techniques have been implemented on a Sylvania
9400 computer system with 32,000 fixed-length words
of memory.  Specifically, the techniques sequence
variable-length records of unrestricted size, produce
long initial strings of data, merge strings of
data at the power of T-1, where T is the number of work
tapes in a system, and do not restrict the volume
of input data.
.A
Goetz, M. A.
.I 852
.T
A Method of Comparing the Time Requirements of Sorting Methods
.A
Hall, M. H.
.I 853
.T
The COBOL Sort Verb
.A
Paterson, J. B.
.I 854
.T
Some Characteristics of Sorting in Computing
Systems Using Random Access Storage Devices
.W
The substantial differences in characteristics
of random access storage and tape devices dictate
that concepts and objectives of computer program design
be considered from the viewpoint of the external
file medium used.  This is particularly true in the
case of sorting.  In a tape-oriented system, the
major sorting problem is that of minimizing merge time
despite the limited orders of merge possible.
 In contrast, sorting in a random access-oriented system
encourages the selection of the optimum order
of merge from many possible orders.  The latter problem
is discussed in this paper, along with criteria
developed for determining the optimum order of merge according
to the various properties of random access
storage devices.  Attention is also given to the problem
of key sorting versus record sorting and the
possibly serious disadvantage of key sorting on a random access system.
.A
Hubbard, G. U.
.I 855
.T
Organization and Structure of Dataon Disk File
Memory Systems for Efficient Sorting and Other
Data Processing Programs
.W
An approach to the organization and structure
of data on Bryant Disc File Memory Systems for
sorting and performing other data processing functions
is presented.  The following areas are covered:
characteristics of Bryant Disc File Systems on the Bendix
G-20 and RCA 301; two proposed "chaining" structures
for data; and functions of a Disk File Executive Routine.
 The concepts for sorting and performing file
maintenance processing using the proposed structure and
executive routine are discussed.  Additionally,
it is shown that sorting can be accomplished
without the use of disk storage work areas.
.A
Goetz, M. A.
.I 856
.T
Sorting with Large Volume, Random Access, Drum Storage
.W
An approach to sorting records is described
using random access drum memory.  The Sort program
described is designed to be a generalized, self-generating
sort, applicable to a variety of record statements.
 This description is divided into three parts.  The
first part presents the operating environment; the
second defines the general solution; the third part
describes the internal sort-merge technique.
.A
Falkin, J.
Savastano Jr., S.
.I 857
.T
Sorting Nonredundant Files-Techniques Used in the FACT Compiler
.W
Some typical file structures, including some
called "non-redundant," are examined,and the
methods used in FACT to sort such files are discussed.
.A
Glore, J. B.
.I 858
.T
A Tape File Merge Pattern Generator
.W
A routine is presented which specifies the
sequence of merge cycles to effect the merging of
sorted tape files.  The routine is designed to minimize
elapsed computer time by varying the power of
the merge cycles, so as to use all the available tape
drives, with its characteristic of assigning one
drive to a single-reel file and two drives to each multiple-reel file.
.A
Cooke, W. S.
.I 859
.T
Computer Planned Collates
.A
French, N.C.
.I 860
.T
A Comparison Between the Polyphase and Oscillating Sort Techniques
.W
A comparison between the Oscillating and Polyphase
Sort techniques is developed for computer
systems having from four to ten tape drives.  The basis
for the comparison is the total reading and writing
required for various number of input strings
and tape drives for the two techniques.
.A
Goetz, M. A.
Toth, G. S.
.I 861
.T
Read-Backward Polyphase Sorting
.W
Read-backward Polyphase sorting provides more
efficient use of the tapes available to a sort
than most other sorting techniques.  Backward Polyphase
produces a continuous merging process from n-1
tapes where n is the total number of tapes being used in
the sorting process.  Any of the available presorting
techniques may be used in conjunction with the Polyphase
merge sort provided that the presort has the
capability of producing both ascending and descending
strings and distributing the strings on the various
tapes as required by the Polyphase Merge.
.A
Gilstad, R. L.
.I 862
.T
String Distribution for the Polyphase Sort
.A
Malcolm Jr., W. D.
.I 863
.T
Multiphase Sorting
.A
Manker, H. H.
.I 864
.T
An Empirical Study of Minimal Storage Sorting
.A
Hibbard, T. N.
.I 865
.T
Internal and Tape Sorting Using the Replacement-Selection Technique
.W
A general technique for sequencing unsorted
records is presented.  The technique is shown to
be applicable for the first stage of a generalized sort
program (the formation of initial strings) as
well as for sorting records within a memory storage (an
internal sort).  It is shown that given N records
in memory storage, records are sequenced using 1+log2
N tests per record, that initial string lengths
will average 2N for random input records, and that reading,
writing and processing can be accomplished
simultaneously if the computer permits such overlap.
.A
Goetz, M. A.
.I 866
.T
Sorting on Computers
.A
Gotlieb, C. C.
.I 867
.T
Least Squares Fitting of Planes to Surfaces Using Dynamic Programming
.W
Dynamic programming has recently been used
by Stone, by Bellman and by Gluss to determine the
closet fit of broken line segments to a curve in an
interval under the constraint that the number of
segments is fixed.  In the present paper successive
models are developed to extend the method to the
fitting of broken plane segments to surfaces z=g(x,y) defined
over certain types of subareas of the (x,y)-space.
 The first model considers a rectangular area, with
the constraint that the plane segments are defined
over a grid in the (x,y)-space.  It is then shown how
this model may be incorporated into an algorithm
that provides successive approximations to optimal fits
for any type of closed area.  Finally, applications
are briefly described.
.A
Gluss, B.
.I 868
.T
A Suggested Method of Making Fuller Use of Strings in ALGOL 60
.A
Shoffner, M. G.
Brown, P. J.
.I 869
.T
Term of Magic Square (Algorithm 148)
.A
Thoro, D.
.I 870
.T
Term of Magic Square (Algorithm 148)
.A
Barnecut, J. N. R.
.I 871
.T
PSIF (Algorithm 147)
.A
Thacher Jr., H. C.
.I 872
.T
Adaptive Numerical Integration by Simpson's Rule (Algorithm 145)
.A
McKeeman, W. M.
.I 873
.T
Random (Algorithm 133)
.A
Poore Jr., J. H.
.I 874
.T
Chebyshev Curvefit (Algorithm 91)
.A
Hale, R. P.
.I 875
.T
Incomplete Elliptic Integrals (Algorithm 73)
.A
van De Riet, R. P.
.I 876
.T
Complete Elliptic Integral (Algorithm 149)
.A
Thacher, H. C.
.I 877
.T
Complete Elliptic Integral of the First Kind (Algorithm 55)
.A
Thacher Jr., H. C.
.I 878
.T
Reduction of a Matrix Containing Polynomial Elements (Algorithm 170)
.A
Hennion, P. E.
.I 879
.T
Newton Interpolation with Forward Divided Differences (Algorithm 169)
.A
Kahan, W.
Farkas, I.
.I 880
.T
Newton Interpolation with Backward Divided Differences
.A
Kahan, W.
Farkas, I.
.I 881
.T
Calculation of Confluent Divided Differences (Algorithm 167)
.A
Kahan, W.
Farkas, I.
.I 882
.T
Monte Carlo (Algorithm 166)
.A
Rodman, R. D.
.I 883
.T
Complete Elliptic Integrals (Algorithm 165)
.A
Thacher Jr., H. C.
.I 884
.T
Orthogonal Polynomial Least Squares Surface Fit (Algorithm 164)
.A
Clark, R. E.
Kubik, R. N.
Phillips, L. P.
.I 885
.T
Modified Hankel Function (Algorithm 163)
.A
Fettis, H. E.
.I 886
.T
XY-move Plotting (Algorithm 162)
.A
Stockton, F. G.
.I 887
.T
Combinatorial of M Things Taken One at a Time,
Two at a Time, Up to N at a Time (Algorithm 161)
.A
Wright, H. V.
Wolfson, M. L.
.I 888
.T
Algorithm 160 Combinatorial of M Things Taken N at A Time
.A
Wolfson, M. L.
Wright, H. V.
.I 889
.T
Official Actions and Responses to ALGOL As a Programming Language
.I 890
.T
Selected Definitions
.W
A selection of the definitions prepared by the
ACM Standards Committee's Subcommittee on Programming
Terminology is presented for review by the ACM membership.
.A
Fritz, W. B.
.I 891
.T
Everyman's Information Retrieval System
.W
The information retrieval problem whose solution
is presented here was posed by a technical
library with limited bubget and personnel.  The solution,
however, is quite general and is applicable
to many different types of retrieval problems.  Further,the
method of solution makes it possible for
many groups who have previously dismissed an information
retrieval program as expensive and difficult
(from a programming stand-point) to reconsider their position,
for the present solution makes it possible
to install an information retrieval program in less than
three months, and with relatively little equipment.
.A
Whitley, V. W.
.I 892
.T
RECOL-A Retrieval Command Language
.W
An interrogation scheme is described for the
retrieval and manipulation of data file records.
 The language of the interrogation scheme allows for selecting
file records with the are of logical condition
statements, defining record classes, associating file
records, editing printed output, and summarizing
the results of the above operations.  Some examples of
a typical file application and the more significant
features of a particular machine implementation are given.
.A
Climenson, W. D.
.I 893
.T
Significance Arithmetic on a Digital Computer
.W
The 7090 at NYU has been modified to include
a "Significance Mode" of operation which is intended
to facilitate the identification of significant bits in
the results of floating-point arithmetic operations.
 The manner in which floating-point arithmetic is handled
in this mode is discussed.  Several numerical
experiments using this mode are described and comparisons
are made with the ordinary "normalized mode."
 Examples include power series evaluation, linear equations
solution, determinant evaluation and matrix
inversion.
.A
Goldstein, M.
.I 894
.T
An Iterative Factorization Technique for Polynomials
.W
An iterative technique is displayed whereby factors
of arbitrary degree can be found for polynomials
in one variable.  Convergence is shown to occur always
if a certain Jacobian does not vanish and if the
initial approximation to a factor is near enough to an
actual factor.  The process is simply programmed,
and preliminary results indicate it to be well adapted
to use with digital computers.  For factors of
degree two, the technique is similar to that of Bairstow,
the present method being somewhat simpler.
.A
Luther, H. A.
.I 895
.T
A Computational Extension of the Variate Difference Method
.W
Presented here is a computational extension
of the variate difference method as developed by
G. Tintner [1].
.A
Scheinok, P. A.
.I 896
.T
Characteristic Values and Vectors of Defective Matrices
.A
Thompson, G. T.
.I 897
.T
Note on the Proof of the Non-existence
of a Phrase Structure Grammar for ALGOL 60
.A
Brown, P. J.
.I 898
.T
Random (Algorithm 133)
.A
Laughlin, D. L.
.I 899
.T
Magic Square (Algorithm 117 & 118)
.A
Bosworth, K. M.
.I 900
.T
Ancestor (Algorithm 79)
.A
Thacher Jr., H. C.
.I 901
.T
Difference Expression Coefficients (Algorithm 79)
.A
Clark, E. S.
.I 902
.T
Determinant (Algorithm 159)
.A
Digby, D. W.
.I 903
.T
Exponentiation of Series (Algorithm 134 )
.A
Fettis, H. E.
.I 904
.T
Fourier Series Approximation (Algorithm 157)
.A
Mifsud, C. J.
.I 905
.T
Algebra of Sets (Algorithm 156)
.A
Mifsud, C. J.
.I 906
.T
Combination in any Order (Algorithm 155)
.A
Mifsud, C. J.
.I 907
.T
Combination in Lexicographical Order (Algorithm 154)
.A
Mifsud, C. J.
.I 908
.T
Test Matrix for Inversion
.A
LaSor, W. S.
.I 909
.T
Arithmetizing Declarations (Corrigendum)
.A
Conway, M. E.
Speroni, J.
.I 910
.T
Selective Instruction Trap for the 7090
.A
Mayer, R. J.
.I 911
.T
A Variant Method of File Searching
.A
McIlroy, M. D.
.I 912
.T
Addressing an Array Yi in k-Dimensions
by Fortran for Analysis of Variance
.A
Garber, M. J.
.I 913
.T
Neliac
.A
Halstead, M. H.
.I 914
.T
Jovial and Its Documentation
.A
Shaw, C. J.
.I 915
.T
Documentation of IPL-V
.A
Newell, A.
.I 916
.T
FORTRAN
.A
Heising, W. P.
.I 917
.T
COMIT
.A
Yngve, V. H.
.I 918
.T
COBOL
.A
Cunningham, J. F.
.I 919
.T
Documentation Problems: ALGOL 60
.A
Naur, P.
.I 920
.T
Toward Better Documentation of Programming Languages
.A
Yngve, V. H.
Sammet, J. E.
.I 921
.T
Incomplete Elliptic Integrals (Algorithm 73)
.A
Meyer, N. A.
.I 922
.T
Multint (Algorithm 32)
.A
Thacher Jr., H. C.
.I 923
.T
Gomory (Algorithm 153)
.A
Bauer, F. L.
.I 924
.T
Nexcom (Algorithm 152)
.A
Hopley, J.
.I 925
.T
Location of a Vector in a Lexicographically Ordered ListAlgorithm 151)
.A
Walter, H. F.
.I 926
.T
Syminv2 (Algorithm 150)
.A
Rutishauser, H.
.I 927
.T
Linear Programming Applied to Ultraviolet Absorption Spectroscopy
.A
White, W. C.
Shapiro, B.
Pratt, A. W.
.I 928
.T
Character Manipulation in FORTRAN
.A
Lewis, T. S.
.I 929
.T
Glossary Construction
.A
Grems, M.
.I 930
.T
Decimal-to-Binary Conversion of Short Fields
.A
Yarbrough, L. D.
.I 931
.T
Systematic Mistake Analysis of Digital Computer Programs
.A
Miller, J. C.
Maloney, C. J.
.I 932
.T
Matrix Inversion by Gauss-Jordan Inversion II (Algorithm 120)
.A
Naur, P.
.I 933
.T
Magic Squares (Algorithm 117 & 118)
.A
Naur, P.
.I 934
.T
Gauss's Method (Algorithm 107)
.A
Naur, P.
.I 935
.T
Calculating Primes by Means of GPS (Algorithm)
.A
Naur, P.
.I 936
.T
A Set of Test Matrices (Algorithm 52)
.A
Naur, P.
.I 937
.T
Inverse of a Finite Segment of the Hilbert Matrix (Algorithm 50)
.A
Naur, P.
.I 938
.T
Invert (Algorithm 42)
.A
Naur, P.
.I 939
.T
Gamma Function (Algorithm 31)
.A
Behrenz, P. G.
.I 940
.T
Generating Discrete Random Variables in a Computer
.W
This note is concerned with details of how to
instruct a computer to choose one from many things
with assigned probabilities.  The method uses a uniform
variable to direct the computer to a memory location;
if this is done by a sequence of appropriately chosen
conditional probabilities, efficient use of memory
space and quite fast programs will result.
.A
Marsaglia, G.
.I 941
.T
A Recursive Program for the General n-Dimensional Integral
.W
A general program is outlined for n-dimensional
integration with variable limits.  The program
is of a recursive nature and uses Simpson's rule combined
with repeated bisection to attain the required
accuracy.  It was developed in the Ferranti Mercury Autocode Scheme.
.A
Cadwell, J. H.
.I 942
.T
FORTRAN Subroutines for Time Series Analysis
.W
The authors have recently been concerned in a
time-series study that constituted a fairly typical
piece of applied statistical research, involving extensive
computations on a moderately large quantity
of data.  Wehave found that the many different numerical
processes that were required could be built
up almost completely from a small number of basic operations,
and a set of FORTRAN subroutines has been
written to perform these.  The main purpose of this
note is to describe these subroutines, but since
the question of general statistical programs is
topical [1], we include some general remarks.
.A
Healy, M. J. R.
Bogert, B. P.
.I 943
.T
Terms Frequently Combined in Problem Description
.A
Grems, M.
.I 944
.T
Storage and Search Properties of a Tree-Organized Memory System
.W
A memory with list properties [1] may be used
to construct numeric, alphabetic or alphanumeric
trees.  Such trees have information storage and retrieval
properties applicable to problems involving
large quantities of data or to problems where the quantity,
word length and distribution of stored information
is not known a priori, or changes rapidly during the processing.
 The purpose of this paper is to examine
the storage and search properties of a tree-organized
storage system assuming that a memory possessing
certain list properties is available.  Of prime interest
is the application where a symbol table, dictionary
or similar file is to be stored and searched.
.A
Scidmore, A. K.
Weinberg, B. L.
.I 945
.T
Arithmetizing Declarations: An Application to COBOL
.A
Conway, M. E.
Speroni, J.
.I 946
.T
Suggestions on ALGOL 60 (ROME) Issues - A Report by the American
Standards Association Subcommittee X3.4.2
.A
Utman, R. E.
.I 947
.T
Supplement to the ALGOL 60 Report
.A
Woodger, M.
.I 948
.T
Note on the Use of Procedures
.A
Healy, M. J. R.
.I 949
.T
Integer and Signed Constants in ALGOL
.W
A few remarks are given on the relations between
syntax and semantics in the programming languages.
 The aim is to point out that, if it is true that the grammar
of a context-free language should be conceived
not only as a strings-generating device but also as a
method for expressing a meaning, then the grammar
of ALGOL is open to some criticism.
.A
Petrone, L.
Vandoni, C. E.
.I 950
.T
Parallel Methods for Integrating Ordinary Differential Equations
.W
This paper is dedicated to the proposition that,
in order to take full advantage for real-time
computations of highly parallel computers as can be
expected to be available in the near future, much
of numerical analysis will have to be recast in a more
"parallel" form.  By this is meant that serial
algorithms ought to be replaced by algorithm which
consist of several subtasks which can be computed
without knowledge of the results of the other subtasks.
As an example, a method is proposed for "parallelizing"
the numerical integration of an ordinary differential
equation, which process, by all standard methods,
is entirely serial.
.A
Nievergelt, J.
.I 951
.T
Rational Chebyshev Approximations
to the Bessel Function Integrals Kis(x)
.W
The second Remes algorithm is used to approximate
the integrals Kis by rational functions.
 The related coefficients for the approximations of
Ki1, Ki2, Ki3 are given for different precisions.
.A
Gargantini, I.
Pomentale, T.
.I 952
.T
Another use of FORTRAN II Chaining
.A
Drath, D. G.
.I 953
.T
Scanning Text with a 1401
.A
Baker, J. J.
.I 954
.T
A Note on the Calculation of Probabilities in an F-Distribution
.A
Smillie, K. W.
Anstey, T. H.
.I 955
.T
A Class of Matrices to Test Inversion Procedures
.A
Cline, R. E.
.I 956
.T
A Family of Test Matrices
.A
Newbery, A. C. R.
.I 957
.T
Method for Partial Rewriting of Magnetic Tape
.A
Miller, J. A.
.I 958
.T
A Case of too Much Precision
.A
Synge, M. J.
.I 959
.T
Mark Sense and Port-A-Punch Programming Inputs
.A
Lubbert, W. F.
.I 960
.T
Curve Fitting with Format Fortran
.A
Garber, M. J.
.I 961
.T
Limited Bit Manipulation Using FORTRAN II
.W
Techniques are developed for manipulating bits
using only FORTRAN II.  These techniques allow
individual bits to be tested, certain fields to be
shifted, and numbers coded in BCD to be converted
to Binary.
.A
Oster, C. A.
.I 962
.T
Double-Precision Squares Root for The CDC-3600
.W
In January of 1960, the late Hans J. Maehly completed
a summary of approximations to the elementary
functions for the CDC-1604 computer.  The approximations
and techniques suggested by Maehly are equally
applicable to the second large computer in the CDC line,
the 3600.  Unlike the 1604, however, the 3600
has built-in double-precision floating-point arithmetic.
 The present work, largely inspired by the successes
of Maehly and his associates, concerns the extension of one
of Maehly's ideas to a double-precision subroutine
for the 3600.
.A
Cody, W. J.
.I 963
.T
Relative Effects of Central Processor and Input-Output
Speeds Upon Throughput on the Large Computer
.W
Presented in this paper is a technique for
determining the relative effects of the internal
speed of the computer and the speed of the input-output
units upon the overall speed of the system. Equations
are derived which permit the determination of these
effects from hardware usage measurements.
.A
White, P.
.I 964
.T
Mechanization of Tedious Algebra-the
e Coefficients of Theoretical Chemistry
.W
A table of formulas for certain integrals
involving Legendre functions has been constructed
mechanically by a program which performed algebraic operations.
 The formulas are all rational algebraic
expressions in a single variable and were constructed
by a recurrence procedure.  They are of interest
in molecular quantum chemistry.  Trivial coding techniques
were used to write the relevant programs in
FORTRAN.  The results were photo composed on a Photon
S-560 system, that was controlled by tapes which
were punched directly from the computer output, so
avoiding manual keyboarding, transcription errors
and keyboarded correction.
.A
Wactlar, H. D.
Barnett, M. P.
.I 965
.T
Greatest Common Divisor (Algorithm 237 [A1])
.A
Bray, T. A.
.I 966
.T
Evaluation of Determinant (Algorithm 224 [F3])
.A
Hasselblad, V.
Rulifson, J.
.I 967
.T
Complementary Error Function (Algorithm 181 [S15])
.A
Clausen, I.
Hansson,L.
.I 968
.T
Radical-Inverse Quasi-Random Point Sequence (Algorithm 247 [G5])
.A
Halton, J. H.
Smith, G. B.
.I 969
.T
Graycode (Algorithm 246 [Z])
.A
Boothroyd, J.
.I 970
.T
Treesort 3 (Algorithm [M1])
.A
Floyd, R. W.
.I 971
.T
Time Sharing in a Traffic Control Program
.W
The Toronto traffic signal control system consists
of a variety of logically distinct computer
programs, all competing for machine time.  To satisfy
these demands, a time-sharing program has been
written whose purpose is to execute, in the order of a
predefined priority, the various subprograms within
the real-time system.  In this paper the more interesting
aspects of the time-sharing program are outlined.
.A
Green, L. E. S.
.I 972
.T
An Executive System Implemented as a Finite-State Automaton
.W
The 473L command and control system used by
the Air Force permits many operators to access
large data files through the use of a computer.  The man-machine
interface is satisfied by several communication
consoles from which operators may enter queries and
view replies.  A data link permits remote stations
to send messages, status reports and inventories directly
to the computer.  The information received
over the on-line data link is used to update the data files
which are stored on disk.  The 473L programming
system is divided into an Executive Control Program and
five components with different processing priorities.
 These priorities permit the system to be most sensitive
to the console inputs and permit the operators
at all the consoles to time share the central processor.
 The Executive Control Program provides for
the orderly transitions of control among the programming
system components. The major emphasis of the
paper is on the technique of using the definition of a
finite-state automaton for organizing the Executive
Control Program.
.A
Heistand, R. E.
.I 973
.T
Estimation of Heart Parameters Using Skin Potential Measurements
.W
A fundamental problem of vector cardiography
is the estimation of the state of the heart on
the basis of skin potential measurements.  A mathematical
model relating ventricular dipoles to surface
potentials is sketched.  Then it is shown that the inverse
problem-that of determining electrical heart
parameters on the basis of skin potential measurements-may
be viewed as a nonlinear multipoint boundary
value problem.  A feasible solution, employing quasilinearization
and high-speed digital computers, is
given.
.A
Bellman, R.
Collier, C.
Kagiwada, H.
Kalaba, R.
Selvester, R.
.I 974
.T
A Technique for Reading Gapless Tapes Makes Electrocardiograph
Analysis Feasible on the IBM 7090
.W
To study arrhythmias and higher frequency
components of the electrocardiogram, long series
of patient heart cycles must be examined before valid
comparison of different heart beats can be made.
A technique is presented for the automatic analysis
of long series heart cycles via a digital computer.
.A
Maher, A. S.
.I 975
.T
The New Program of Work for the International
Standard Vocabulary in Computers and Information
Processing
.A
Traub, J. F.
.I 976
.T
Fresnel Integrals (Algorithm 213 [S20])
.A
Gray, M.
.I 977
.T
Conversions Between Calendar Date and
Julian Day Number (Algorithm 199 [Z])
.A
Oppenheim, D. K.
.I 978
.T
Fresnel Integrals (Algorithm 244 [S20])
.A
Lotsch, H.
.I 979
.T
Logarithm of a Complex Number (Algorithm 243 [B3])
.A
Collens, D. S.
.I 980
.T
Multiple-Precision Arithmetic and the Exact
Calculation of the 3-j, 6-j and 9-j Symbols
.W
Described in this paper is a system of general-purpose
multiple-precision fixed-point routines
and their use in subroutines which calculate exactly
the quantum-mechanical 3-j, 6-j and 9-j symbols
of large arguments.
.A
Maer, R. M.
Redlich, M. G.
.I 981
.T
Rounding Problems in Commercial Data Processing
.W
A common requirement in commercial data processing
is that the sum of a set of numbers, rounded
in a generally understood manner, be equal to the sum
of the numbers rounded individually.  Four rounding
procedures are described to accomplish this.  The particular
procedure that is appropriate depends upon
whether the numbers being accumulated can vary in sign,
whether their sum can vary in sign, and whether
the last number being summed can be recognized as such prior to its rounding.
.A
Kelley, T. B.
.I 982
.T
An Inductive Approach to Language Translation
.W
The possibility of natural language translation
by means of fixed operations on example translations
is considered.  The conception of sentence translation
which motivates the work is informally presented,
and the measurement of physical similarity in pairs of
strings is discussed, a notion which plays a central
role in the proposed type of translator.  Experimental
evidence is presented in support of the premise
upon which this conception is based.
.A
Faulk, R. D.
.I 983
.T
Take-up reels for One-Inch Perforated Tape for
Information Interchange (Proposed American Standard)
.I 984
.T
Report on Input-Output Procedures for ALGOL 60 (IFIP)
.I 985
.T
Report on SUBSET ALGOL 60 (IFIP)
.I 986
.T
Proposed Amendment to Proposed American Standard
on Specification for General-Purpose Paper Cards
for Information Processing
.I 987
.T
FORTRAN vs. Basic FORTRAN (A Programming Language
for Information Processing on Automatic Data
Processing Systems)
.I 988
.T
History and Summary of FORTRAN Standardization Development for the ASA
.A
Heising, W. P.
.I 989
.T
A Method of Syntax Specification
.A
Iverson, K. E.
.I 990
.T
Constraint-Type Statements in Programming Languages
.W
A proposal is made for including in a programming
language statements which imply relations
between variables but which are not explicit assignment
statements.  The compiler sets up a Newtonian
iteration making use for the purpose of a routine for formal differentiation.
.A
Wilkes, M. V.
.I 991
.T
Gamma Function with Controller Accuracy (Algorithm 225 [S14])
.A
Bray, T. A.
.I 992
.T
Gamma Function (Algorithm 221 [S14])
.A
McCombs, V. K.
.I 993
.T
Kutta Merson (Algorithm 218 [D2])
.A
Priebe, K. B.
.I 994
.T
Stringsort (Algorithm 207 [M1])
.A
Blair, C. R.
.I 995
.T
Steep1 (Algorithm 203 [E4])
.A
Wallack, P.
.I 996
.T
Permutations of a Set with Repetitions (Algorithm 242 [G6])
.A
Sag, T. W.
.I 997
.T
Patent Protection of Computer Programs
.A
Jacobs, M. C.
.I 998
.T
Computer Programs are Patentable
.A
Hamlin, K. B.
.I 999
.T
Joint Inventorship of Computers
.A
Hauptman, G. A.
.I 1000
.T
Computer Patent Disclosures
.A
Kates, J. P.
.I 1001
.T
Copyright Aspects of Computer Usage
.W
This paper is concerned with the question of
what constitutes infringement of a copyright on
a book or other nondramatic literary work when the work
is fed into a computer and is indexed, analyzed,
partially reprinted, or otherwise utilized by the computer
to produce eye-readable output.  The question
of copyrightability of programs and infringement of copyrights
on programs is also discussed.  The paper
is directed primarily to a discussion of the present
law.  Some aspects of the proposed new copyright
law are also included.  General recommendations are
made with respect to the proposed revision of the
copyright law.
.A
Lawlor, R. C.
.I 1002
.T
A Rapid Method for Digital Filtering
.W
Since much of the computer time spent in time-series
analysis is used for multiplications,
a minimum multiplication method was devised for digital
filtering, with the expectation that it would
be useful in the on line, real-time analysis of biological
data.  The filters are constructed from a succession
of readily analyzable components in a manner that facilitates
cascading.  The repertoire of frequency
response curves includes relatively good low-pass and
band-pass designs.  Programs are available for
implementing both the synthesis of these filters, and
their application on computers whose assemblers
allow the definition of recursive macros.
.A
Whittlesey, J. R. B.
.I 1003
.T
A Computer Analysis Method For Thermal Diffusion in Biochemical Systems
.W
In the thermal detection of rapid biochemical
reactions it is necessary to correct the temperature
data for transient heat conduction losses in a cylindrical
calorimeter.  To handle the complexities arising
from varying thermal-relaxation times of concentric insulating
layers, a computer program was developed
which gives the temperature distribution of the system
as a function of radius and time.  This distribution
is corrected at each step by a subroutine which calculates
the instantaneous chemical state of there
action, as well as the heat produced by this reaction.
 The program is based on a direct statement of
Fourier's law of heat conduction and the chemical rate
equation to provide a "bookkeeping law" to follow
the reactants and the flow of heat packets, in such a
way that the computer continually stores the heat
distribution.  A computer analysis method is here regarded
as one in which the physical laws of a process
are used explicitly in the program. Usually this results
in by passing much of the mathematical procedures
conventionally used.  The program was tested against
some known exact solutions of the heat equation
and gave identical results, and compared well with experimental
data of a known biochemical reaction.
 The construction of computer programs based on the direct
statement of the physical laws is a principle
of general applicability which has been applied
to several other physical phenomena.
.A
Davids, N.
Berger, R. L.
.I 1004
.T
Arctangent (Algorithm [B1])
.A
Mills, K. W.
.I 1005
.T
Coordinates on an Ellipsoid (Algorithm 240 [Z])
.A
Dorrer, E.
.I 1006
.T
A Storage Allocation and Reference Structure
.W
A method is proposed and discussed which allows
a subscripted-variable capability (in the FORTRAN
sense) to be added to AUTOCODER-Type assembly systems.
.A
Fitzwater, D. R.
.I 1007
.T
Extension of Existing Compilers By Sophisticated Use of Macros
.W
A description is presented of an application
in which macros and string concatenation were
employed to add a new facility to BELFAP.
.A
Benett, R. K.
Neumann, H. D.
.I 1008
.T
Scheduling Meetings with a Computer
.W
Computer scheduling of papers as it was developed
for the 1960 meeting of the Federation of
American Societies for Experimental Biology (FASEB) is described.
 The FASEB meeting is the largest scientific
meeting held in the United States each year.  The technique
developed for FASEB can be applied to schedule
any meeting with parallel sessions.
.A
Schultz, C. K.
Brooks, A.
Schwartz, P.
.I 1009
.T
Solution of Combinatorial Problems Using Generating
Functions on a Variable-Field Computer
.W
The utility of generating functions in solving
combinatorial problems is discussed.  Particular
implementation results are presented and evaluated.
.A
Weinberg, G. M.
.I 1010
.T
A Multiuser Computation Facility for Education and Research
.W
Present-day computing facilities are limited
in their value for scientific research by inability
to interact strongly with users.  The full power of a
research computing instrument should be available
at many terminals that give each user the ability to generate,
correct and operate any procedure he wishes,
either simple or complex.  Implementation is described
for a small-scale multiuser computer system that
permits several users to work independently with the
machine, and to obtain satisfactory response using
typewriter communication.
.A
Dennis, J. B.
.I 1011
.T
Logarithm of a Complex Number (Algorithm 48 [B3])
.A
Collens, D. S.
.I 1012
.T
Formal Parsing Systems
.W
Automatic syntactic analysis has recently become
important for both natural language data processing
and syntax-directed compilers.  A formal parsing system
G = (V,u,T,R) consists of two finite disjoint
vocabularies, V and T, a many-many map, u, from V onto
T, and a recursive set R of strings in T called
syntactic sentence classes.  Every program for automatic
syntactic analysis determines a formal parsing
system.  A directed production analyzer (I,T,X,p) is a
nondeterministic pushdown-store machine with internal
vocabulary I, input vocabulary T, and all productions
of p in the form:  (Z,a) -> aY1 ... Ym where  Z,
Yi are elements of the set I and a is an element of the
set T.  Every context-free language can be analyzed
by a directed production analyzer.  The Kuno-Oettinger
multiple-path syntactic analyzer for English is
a concrete example of a directed production analyzer
and of a working parsing algorithm.  The connection
between structures assigned by the analyzer and those of
a conventional phrase structure grammar is examined
in this paper.
.A
Greibach, S. A.
.I 1013
.T
Final Examination Scheduling
.W
A method for scheduling final examinations
to yield a minimal number of student conflicts is
described.  The "minimization" is achieved by repetitively
evaluating a nonlinear set of equations.
Imbeded in the process is a random or Monte Carlo selection
of assignments.  As in such heuristic techniques,
the solution may not be optimum and many solutions
may be found which yield locally minimal results.
 Computer programs are described and empirical results given.
.A
Broder, S.
.I 1014
.T
Machine Controls for Analysis of Variance
.W
A major problem in using the analysis of variance,
as the number of factors increases, is the
exponential rise in the number of interactions.  Even
though the experimenter may not be interested in
these interactions it is impossible to ignore them in
most experimental designs because of the problem
of getting error terms.  It is natural therefore to look
to the computer to handle the bulk of work involved
in computing the interactions.  A program device
to get the computer to do this is described.
.A
Weldon, R. J.
.I 1015
.T
Near-Minimax Polynomial Approximations and Partitioning of Intervals
.W
A method of near-minimax polynomial approximation
is described.  As a by-product, this method
provides a formula for an estimate of the maximum error
associated with a given degree of approximation.
 Using this formula, a partitioning algorithm is obtained
for dividing a basic interval into subintervals
for which approximations of equal degree give equal maximum error.
.A
Fraser, W.
Hart, J. F.
.I 1016
.T
Interchangcable Perforated Tape Variable Block
Formats for Positioning and Straight Cut (RS-273)
and Contouring and Contouring/Positioning (RS-274) Numerically
Controlled Machine Tools (Proposed American
Standards)
.I 1017
.T
Comments on Bit-Sequencing of the ASCII
in Serial-by-Bit Data Transmission
.A
Bemer, R. W.
Booth, J.
.I 1018
.T
Gauss (Algorithm 209 [S15])
.A
Pike, M. C.
.I 1019
.T
XY move Plotting (Algorithm 162 [J6])
.A
Cavin, D. K.
.I 1020
.T
Free Field Read (Algorithm 239 [I5])
.A
McKeeman, W. M.
.I 1021
.T
Conjugate Gradient Method (Algorithm 238 [F4])
.A
Reeves, C. M.
.I 1022
.T
Greatest Common Divisor (Algorithm 237 [A1])
.A
Peck, J. E. L.
.I 1023
.T
Bessel Functions of the First Kind (Algorithm 236 [S17])
.A
Gautschi, W.
.I 1024
.T
A Note on the Formation of Free List
.A
Waite, W. M.
.I 1025
.T
A Method of Syntax-Checking ALGOL 60
.W
A syntax checker was designed based on the syntax
of ALGOL as described in the ALGOL 60 Report
[Communications of the ACM, May, 1960].  Since the definition
of the elements of the language is recursive
it seemed most desirable to design the syntax checker
as a set of mutually recursive processors tied
together by subroutines which perform certain bookkeeping
functions.  Because of the recursive nature
of the language and of the syntax checker the problem
of recovery after an error required much attention.
 A method was devised which permits most programs
to be checked completely despite errors.
.A
Lietzke, M. P.
.I 1026
.T
Divide-and-Correct Methods for Multiple Precision Division
.W
A division problem is defined and notation
to relate it to the problem of multiple precision
operation in a digital computer is introduced.  A basic
divide-and-correct method for multiple precision
division is formulated and its known properties briefly
reviewed.  Of particular interest is the fact
that the method produces at each step a set of precisely
three estimates for the desired result, one
of which is exact.
.A
Stein, M. L.
.I 1027
.T
An Alternate Checksum Method
.A
Newhall, N. S.
.I 1028
.T
Investigation of a New Analytical Method
for Numerical Derivative Evaluation
.W
A recently proposed analytical approach to
numerical derivative evaluation is discussed.  The
technique is shown to be both accurate and easy to
apply, though certain indicated modifications are
required.  Its use should greatly facilitate the writing
and debugging of programs requiring derivatives
of highly complex functions.
.A
Wilkins, R. D.
.I 1029
.T
A Simple Automatic Derivative Evaluation Program
.W
A procedure for automatic evaluation of total/partial
derivatives of arbitrary algebraic functions
is presented.  The technique permits computation of
numerical values of derivatives without developing
analytical expressions for the derivatives.  The key
to the method is the decomposition of the given
function, by introduction of intermediate variables,
into a series of elementary functional steps.  A
library of elementary function subroutines is provided
for the automatic evaluation and differentiation
of these new variables.  The final step in this process
produces the desired function's derivative.
The main feature of this approach is its simplicity.
 It can be used as a quick-reaction tool where the
derivation of analytical derivatives is laborious and
also as a debugging tool for programs which contain
derivatives.
.A
Wengert, R. E.
.I 1030
.T
Techniques for the Simulation of Computer Logic
.W
The simulation of a digital computer is an
integral part of most computer design automation
systems.  The evaluation of the Boolean functions which
characterize the computer being simulated constitutes
one major portion of a simulation system.  Four general
procedural classes for evaluating these functions
are defined.  Toward greatly increased efficiency of a simulation
system, methods are presented for simultaneously
evaluating many functions for one set of values of the
variables,and for evaluating simultaneously one
function for many sets of values for the variables.
.A
Breuer,M. A.
.I 1031
.T
A Note on Starting the Newton-Raphson Method
.W
Determination of a suitable initial estimate
for a root of an equation f(x) = 0 by means of
computing the roots of a sequence of related equations is described.
.A
Beyer, W. A.
.I 1032
.T
Theoretical Considerations in Information Retrieval Systems
.W
Information storage and retrieval systems are composed
of three major components: (a) identification
of information and tagging it for effective retrieval,
(b) searching strategy, how to enter the file
to circumvent the scanning of nonrelevant material, and
(c) file organization to make access to information
efficient.  For identification of information the paper
suggests that a metalanguage (recently discussed
in a paper by Goffman, Verhoeff and Belzer) associated
with an object language be used.  For searching
strategy, a linear model for an evaluation function
of relevancy is developed which rewards the system
for retrieving relevant documents and not retrieving
the nonrelevant, and penalizes the system for the
escaped relevant documents and false drops.  The inadequacies
of a linear model are indicated.  Two approaches
to file organization are discussed.  One is self-organization
of the file based on its history and past
performance, and the second is a self-generating subset
of the file with a high probability of being
relevant.
.A
Belzer, J.
Goffman, W.
.I 1033
.T
Experimental Personalized Array Translator System
.W
A system designed for intimate man-machine
interaction in a general-purpose problem-solving
environment is experimentally operational.  The system
utilizers an array-oriented symbolic source language
containing powerful statement types.  These include numeric,
Boolean, relational and selection operators
on operands which can be entire arrays.  The system also
permits simple specification of test and argument
arrays in single statements.  The completely symbolic
operating system includes display and entry of
program and data.  Sequence control is aided by an interrupt
switch which allows the user to interact
with the program during execution. In addition to normal
stored program sequencing, the system provides
trace options and the ability to enter any statement
for immediate execution.  Present implementation
of the system is with an interpretive translator on an IBM 1620 computer.
.A
Hellerman, H.
.I 1034
.T
Autosate
.W
An automated data system analysis technique is
described. The technique is designed to alleviate
some of the principal problems that beset current analysis-large
data workloads, long span of time between
project inception and system operational date, the lack
of explicit directions for conducting data system
analysis and using the results, and the lack of a technique
to control data system changes throughout
its lifetime. The analysis is geared to determining workload,
relationships and storage characteristics
of documents in the information network automatically.
.A
Gatto, O. T.
.I 1035
.T
Characteristics of the FORTRAN CEP Language
.W
The FORTRAN CEP languages differs from FORTRAN
II mainly because: (1) it extends the variety
of the modes for real quantities; (2) it allows suitable
mixtures, in an input/output list or in an expression,
of quantities that occur under different modes; (3)
it makes it possible to address a greater number
of input/output equipment; and (4) it removes the restrictions
on the complexity of the list of quantities
to be transmitted between the magnetic core memory
and the drum or the magnetic tape units.
.A
Mancino. O. G.
.I 1036
.T
Remark on Further Generalization of ALGOL
.A
Garwick, J. V.
.I 1037
.T
Reduction of a Matrix Containing Polynomial
Elements (Algorithm 170 [F3])
.A
Priebe, K. B.
.I 1038
.T
Crout with Equilibration and Iteration (Algorithm 135 [F4])
.A
McKeeman, W. M.
.I 1039
.T
Summation of Fourier Series (Algorithm 128 [C6])
.A
Thacher Jr., H. C.
.I 1040
.T
Romberg Integration(Algorithm 60 [D1])
.A
Thacher Jr., H. C.
.I 1041
.T
Random Permutation (Algorithm 235 [G6])
.A
Durstenfeld, R.
.I 1042
.T
Poisson-Charlier Polynomials (Algorithm 234 [S23])
.A
Simoes Pereira, J. M. S.
.I 1043
.T
Talk-A High-Level Source Language Debugging
Technique With Real-Time Data Extraction
.W
TALK, meaning Take A Look, is a debugging technique
which aids substantially in debugging complex
real-time programming systems by interrupting the users
program at desired points to extract previously
specified data.  The extracted data is later edited,
listing the associated data with its high-level
source language identification.
.A
verSteeg, R. L.
.I 1044
.T
An Automatic Loader for Subroutine Nests
.W
A method for automatic loading of library subroutines,
which can be adapted to operate in conjunction
with any conventional two-pass assembler is described.
 The method is specifically designed to cope with
a nested library structure.
.A
Kanner, H.
.I 1045
.T
Programming Analysis of Variance by Sequences
of Operators and Isomorphic Mappings
.W
A special operator calculus developed by Hartley
in 1956 together with a new mapping scheme
has been found to be efficient in programming analysis
of variance for multifactor experiments. The operator
calculus and the mapping scheme are described in detail.
.A
Peng, K. C.
.I 1046
.T
A Compiler-Building System Developed by Brooker and Morris
.W
In a number of articles published during the
past two years, R. A. Brooker and D. Morris (joined
by J.S. Rohl in their most recent paper have presented
a very interesting programming system that they
have developed for the Ferranti Atlas computer.  The
present paper describes some of the major features
of their system. it expands on some points that the original
authors cover briefly, and treats only very
lightly some topics to which they devote considerable space.
 The purpose of this paper is purely expository.
 Except in some very small details, and in some comments,
it does not intentionally depart from or add
to the material published in the listed references.
.A
Rosen, S.
.I 1047
.T
Generation of Test Matrices by Similarity Transformations
.W
A method for obtaining test matrices with
a prescribed distribution of characteristic roots
is given.  The process consists of using particularly
simple similarity transformations to generate full
matrices from canonical forms.  The matrices generated
also have known characteristic vectors, inverses
and determinants.
.A
Ortega, J. M.
.I 1048
.T
Approximate Solution of Axially Symmetric Problems
.W
A variety of physical problems in such diverse
fields as electrostatic  field theory, heat
and ideal fluid flow, and stress concentration theory
reduce, under the assumption of axial symmetry,
to the study of an elliptic partial differential equation.
 Dirichlet-type problems associated with this
equation are studied on regions whose boundaries include
a nondegenerate portion of the x-axis and exceedingly
accurate numerical methods are given for approximating solutions.
.A
Greenspan, D.
.I 1049
.T
Numerical Solution of Nonlinear Two-Point
Boundary Problems by Finite Difference Methods
.W
Solution of nonlinear two-point boundary-value
problems is often an extremely difficult task.
 Quite apart from questions of reality and uniqueness,
there is no established numerical technique for
this problem.  At present, shooting techniques are the
easiest method of attacking these problems.  When
these fail, the more difficult method of finite differences
can often be used to obtain a solution.
This paper gives examples and discusses the finite difference
method for non-linear two-point boundary-value
problems.
.A
Holt, J. F.
.I 1050
.T
A Parts Breakdown Technique Using List Structures
.W
List structured parts breakdown is proposed
and discussed.  Implementation facts are presented
on operating program using these techniques.
.A
Brian, W. J.
.I 1051
.T
Multiword List Items
.W
The list concept as originally proposed by
Newell, Simon and Shaw specified single computer
words as elements of a list.  This report describes the
use of two or more consecutive words as one element.
 Such use results in a considerable saving in both the
space required to hold a given amount of data,
and in the execution time required to perform a given
process on the data.  Following a brief description
of standard list structures with single-word items, the
multiword items are introduced.  Then variable-length
items are described, along with the corresponding space-utilization
problems.  Finally, several examples
are given to illustrate the use of multiword lists. This
paper attempts to draw together various recent
papers which have applied some of these concepts in different
ways, and indicate how they relate to the
more general problems.
.A
Comfort, W. T.
.I 1052
.T
Reducing Truncation Errors by Programming
.W
In accumulating a sum such as in a numerical
integration with a large number of intervals,
the sum itself becomes much larger than the individual
addends.  This may produce a less accurate sum
as the number of intervals is increased.  Separate variables
can be established as accumulators to hold
partial sums within various distinct intervals.  Thus,
the extensive successive truncations are eliminated.
.A
Wolfe, J. M.
.I 1053
.T
Design and Implementation of a General-Purpose Input Routine
.W
A general-purpose input routine is discussed
and advocated for FORTRAN.  The philosophy of
such programs is examined and exemplified.
.A
Hassitt, A.
.I 1054
.T
Gauss-Seidel (Algorithm 220 )
.A
Batson, A. P.
.I 1055
.T
q-Bessel Functions In(t) (Algorithm 214)
.A
Simoes Pereira, J. M. S.
.I 1056
.T
Shellsort (Algorithm 201)
.A
Batty, M. A.
.I 1057
.T
Critical Path Scheduling (Algorithm 40)
.A
Hoffman, I. A.
.I 1058
.T
Simpson's Rule for Multiple Integration (Algorithm 233)
.A
Olynyk, F.
.I 1059
.T
Heapsort (Algorithm 232)
.A
Williams, J. W. J.
.I 1060
.T
Matrix Inversion (Algorithm 231)
.A
Boothroyd, J.
.I 1061
.T
Matrix Permutation (Algorithm 230)
.A
Boothroyd, J.
.I 1062
.T
Symbol Manipulation in FORTRAN-SASP I Subroutines
.W
A set of subroutines for use in FORTRAN are
described whose purpose is to synthesize output
strings from (i) input strings which have been analyzed
by the SHADOW general syntactic analysis subroutine
reported earlier, and/or (ii) packed BCD strings formed
in any way.  Function-type subroutines are included
for intermediate manipulations, which are performed
on the strings which are stored in an abbreviated
internal representation.  The automatic way in which
an internal representation for each newly created
substring is stored sequentially in a block of common
storage, and the manner in which a storage block
is dynamically allocated for that purpose, are discussed.
.A
Bailey, M. J.
Barnett, M. P.
Burleson, P. B.
.I 1063
.T
One-Inch Perforated Paper Tape for Information
Interchange (Proposed American Standard)
.I 1064
.T
Perforated Tape Code for Information
Interchange (Proposed American Standard)
.I 1065
.T
Bit Sequencing of the American Standard Code for
Information Interchange (ASCII) in Serial-by-Bit
Data Transmission (Proposed American Standard)
.I 1066
.T
Growing Applications of Linear Programming
.W
Use of linear programming models has grown so
extensively in recent years that the whole concept
for organizing a computer code has undergone a radical
change.  It no longer is adequate merely to reduce
a mathematical algorithm (i.e. the simplex method) to
a computer code.  An advanced code must cope with
such a variety of situations that the respective computer
subprograms must be organized into an integrated
system.  Emphasis in this paper is devoted to the underlying
principles upon which future linear programming
systems must be based.  These viewpoints are influenced
by the new demands that applications within the
petroleum industry are placing on such systems.  Some
of the components of such a system are: translation
of problem statement in terms of basic data to linear
programming matrix coefficients, data transmission
for direct computer entry, data file at the computer center,
data processing and editing prior to solving
the simplex algorithm, an efficient and reliable code
for solving the above-mentioned algorithm, and
flexible means for summarizing the results.
.A
Aronofsky, J. S.
.I 1067
.T
Picture Generation With a Standard Line Printer
.W
A method is described for producing gray-toned
pictures on a line printer by utilizing the
different degrees of blackness of standard print characters.
 Gray scales with 17, 32 and 64 levels have
been devised.  Scanned images of blood cells are used to display the technique.
.A
Perry, B.
Mendelsohn, M. L.
.I 1068
.T
A FORTRAN II Load-Time-Saver
.A
Ackermann, A. F.
.I 1069
.T
A Method for Comparing the Internal Operating Speeds of Computers
.A
Raichelson, E.
Collins, G.
.I 1070
.T
Expand, A System for Input Card Replication
.A
Warrington, J. A.
Norris, J. H.
.I 1071
.T
Computer-Usage Accounting for Generalized Time-Sharing Systems
.W
The current development of general time-sharing
systems requires a revision of accounting procedures
for computer usage. Since time-sharing system users
operate concurrently, it is necessary to be more
precise as to the amount of computer time and storage
space that a user actually utilizes.  The various
cost factors which should be considered for computer usage
accounting in generalized time-sharing systems
are discussed.
.A
Rosenberg, A. M.
.I 1072
.T
An Improved Equivalence Algorithm
.W
An algorithm for assigning storage on the basis
of EQUIVALENCE, DIMENSION and COMMON declarations
is presented.  The algorithm is based on a tree structure,
and has reduced computation time by 40 percent
over a previously published algorithm by identifying all
equivalence classes with one scan of the EQUIVALENCE
declarations.  The method is applicable in any problem
in which it is necessary to identify equivalence
classes, given the element pairs defining the equivalence relation.
.A
Galler, B. A.
Fisher, M. J.
.I 1073
.T
A Fast Procedure for Generating Exponential Random Variables
.W
A very fast method for generating exponential
random variables in a digital computer is outlined.
.A
MacLaren, M. D.
Marsaglia, G.
Bray, T. A.
.I 1074
.T
Shanks (Algorithm 215)
.A
Schumaker, L.
.I 1075
.T
Shuttlesort (Algorithm 175)
.A
Juelich, O. C.
.I 1076
.T
Multiple Integration (Algorithm 146)
.A
Wirth, N.
.I 1077
.T
Chebyshev Curve Fit (Algorithm 91)
.A
Naur, P.
.I 1078
.T
Elementary Functions by Continued Fractions (Algorithm 229)
.A
Morelock, J. C.
.I 1079
.T
Q-Bessel Functions (Algorithm 228)
.A
Simoes Pereira, J. M. S.
.I 1080
.T
Chebyshev Polynomial Coefficients (Algorithm 227)
.A
Cyvin, S. J.
.I 1081
.T
Normal Distribution Function (Algorithm 226)
.A
Cyvin, S. J.
.I 1082
.T
Gamma Function with Controlled Accuracy (Algorithm 225)
.A
Cyvin, S. J.
Cyvin, B. N.
.I 1083
.T
An Experiment in a User-Oriented Computer System
.W
A version of a software-hardware system for
the purpose of facilitating the programming and
analysis of well-formulated problems is described.  A modified
Flexowriter is used to generate computer-acceptable
input when equations or computable requests are typed
in much the same manner as they would appear in
conventional mathematical texts.  The typing and language
rules are quite flexible and unrestrictive.
 While the compiler part is efficient, the system as
a whole has much broader aspects as a tool for the
study of problem solving and self-teaching systems.
.A
Klerer, M.
May, J.
.I 1084
.T
On Declaring Arbitrarily Coded Alphabets
.W
The inability of existing programming languages
to handle character strings from more than
one or two alphabets is mentioned and a scheme for declaring
additional alphabets is proposed.  The scheme
provides for: many-to-one encodings, right or left
justification, collating sequences different from
numeric sequence, variations in character size (number
of bits.) from alphabet to alphabet, and arbitrary
source-language character representation.
.A
Shaw, C. J.
.I 1085
.T
Specification for General-Purpose Paper Cards for
Information Processing (Proposed American Standard)
.I 1086
.T
A Proposal for Input-Output Conventions in ALGOL
60-A Report of the Subcommittee on ALGOL of
the ACM Programming Language Committee
.I 1087
.T
Problems in Automatic Abstracting
.W
A variety of problems concerning the design
and operation of an automatic abstracting system
are discussed.  The purpose is to a general view of
several major problem areas.  No attempt is made
to discuss details or to indicate preferences among alternative solutions.
.A
Edmundson, H. P.
.I 1088
.T
Menu Planning by Computer
.W
A computer code has been developed which plans
menus by finding minimum cost combinations of
menu items such that the daily dietary, gastronomic
and production requirements can be satisfied for
a sequence of days.  A fast, special integer programming
algorithm is described which approximates the
theoretical solution to the problem.  If necessary, any
menu can be changed on-line and then post-optimized.
 Up to 30 percent saving on food cost is possible.
A FORTRAN program for the IBM 1410 is available on
request.  A considerable amount of data processing
must precede the implementation of the system.
.A
Balistfy, J. L.
.I 1089
.T
Designing a Computer Center
.A
Denison, A.
Popov, G.
.I 1090
.T
Incomplete Beta Function Ratios (Algorithm 222)
.A
Gautschi, W.
.I 1091
.T
Hypergeometric and Confluent Hypergeometric (Algorithm 191 & 192)
.A
Thacher Jr., H. C.
.I 1092
.T
Nonrecursive Adaptive Integration (Algorithm 182)
.A
Butler, H. S.
.I 1093
.T
Evaluation of Determinant (Algorithm 224)
.A
Rotenberg, L. J.
.I 1094
.T
Prime Twins (Algorithm 223)
.A
Shimrat, M.
.I 1095
.T
Decimal Tables of Binary Coded Tables
.A
Griebrok, M.
.I 1096
.T
On Avoiding Matrix Reversals Between 7090 FORTRAN II and 7090 FORTRAN IV
.A
Stevens, D.
Benson, B.
.I 1097
.T
An Algorithm for Converting Integers from Base A to Base B
.W
A little known, simple algorithm for integer
conversion between number systems is presented
and proved.
.A
Gladwin, H. T.
.I 1098
.T
A Comparison of List-Processing Computer Languages
(Including a Detailed Comparison of COMIT,
IPL-V, LISP 1.5, and SLIP)
.W
A detailed comparison is presented of COMIT,
IPL-V, LISP 1.5 and SLIP - four well-known computer
programming languages which, among them, exhibit all the
principal characteristics of existing list-processing
languages.  Important common features of list-processing
languages are reviewed: forms of data structures
which are manipulated, necessity for dynamic allocation
of storage, use of pushdown stores, and use of
recursive operations.  Principal differences between the
four languages under consideration are detailed:
representations of data, both by the programmer and within
the machine; methods for storage allocation;
programming formalisms and special processes available,
including arithmetic facilities; and usability
in terms of availability, documentation, learning aids
and debugging facilities.  A rough comparison
shows that all the languages discussed have approximately
the same speed.  Finally, the authors give
some heuristics to aid in the selection of one of these
languages for use in particular problem applications,
concluding that no one of the languages considered is
distinctly superior in all possible list-processing
applications.
.A
Bobrow, D. G.
Raphael, B.
.I 1099
.T
Professional Computer Work for the Blind
.W
Developments in computer technology have opened
new professional opportunities for the intelligent
blind.  Since there are few if any occupations in which the
blind can participate without serious disadvantage,
the opportunities offered them to gain entrance into
various occupations through computer use including
that of programmer, is important for future rehabilitation
planning. Also of immediate interest is the
fact that the blind may be especially suited for programming
work.  Because of intense training in and
constant experience with locating objects in the unseen
environment and also because of superbly trained
memory, the blind brings to the work of programming skills
which the sighted has had little need to acquire.
 These qualifications should result in fewer debugging
problems and make the blind a valuable addition
to any systems group.  Before the blind could become a
serious professional, a number of aids and techniques
had to be developed that can mediate between machines
and programmer.  This paper describes the techniques
and aids which were designed by the staff of the Medical
Computing Center of the University of Cincinnati
College of Medicine.
.A
Sterling, T. D.
Lichstein, M.
Scarpino, F.
Stuebing, D.
.I 1100
.T
Status of Computer Sciences Curricula in Colleges and Universities
.A
Atchison, W. F.
Hamblen, J. W.
.I 1101
.T
The Place of Logical Design and Switching
Theory In The Computer Curriculum
.A
Muller, D. E.
.I 1102
.T
Mechanical Languages: A Course Specification
.A
Gorn, S.
.I 1103
.T
Logic for the Computer Sciences
.A
Korfhage, R. R.
.I 1104
.T
An Undergraduate Curriculum in Numerical Analysis
.A
Forsythe, G. E.
.I 1105
.T
On Introducing Digital Computing
.A
Arden, B. W.
.I 1106
.T
Programming of Digital Computers
.A
Perlis, A. J.
.I 1107
.T
Computers and Education
.A
Keenan, T. A.
.I 1108
.T
Digital Data Processor for Tracking the Partially Illuminated Moon*
.W
A study of lunar tracking techniques and fabrication
of a breadboard to assess the feasibility
of the best technique selected was conducted to define
a tracking system for observation of the sight line
to the center of a partially illuminated moon.  The
data processing portion of the system is presented
in detail and then described in general are the operation
of the tracker head assembly for data readout,
the operation of the entire system and the effect data
processing considerations have on the design of
the tracker system.  The system basically consists of
an optical sensor, digital computer and tracker
drive mechanism.  The three system units, connected
in cascade, comprise the control loop.  For this
application, an optical telescope with a radial mechanical
scanning mechanism was used that read out
lunar sight line measurement information.  This information
is sequentially read into a special purpose
digital computer that extracts the measurements and
computes the error signals that drive the tracker
to the appropriate attitude.
.A
Wilcox, H. J.
.I 1109
.T
Conversion of a Power to a Series of Chebyshev Polynomials*
.W
Even slowly convergent power series can be
rearranged as series in Chebyshev polynomials if
appropriate sequence transformations are used in evaluating
the coefficients.  The method is illustrated
by computing the coefficients for the expansion
of the logarithm and dilogarithm.
.A
Thacher Jr., H. C.
.I 1110
.T
A Fourier Series Method for the Numerical Solution
of a Class of Parabolic Partial Differential
Equations*
.W
A Fourier series method is described which, when
applied to a certain class of parabolic partial
differential equations, reduces the problem to a system
of ordinary differential equations.  An application
is given for which the method shows a considerable advantage
over conventional finite difference methods.
.A
Forrington, C. V. D.
.I 1111
.T
A Class of Iterative Techniques For the Factorization of Polynomials*
.W
A method of iteration is developed in terms
of a function of somewhat arbitrary character.
 Sufficient conditions are given for convergence of
the process, yielding factors of arbitrary degree
for polynomials in one variable.  Both Lin's method
and Newton's method occur as special cases.
.A
Luther, H. A.
.I 1112
.T
A Technique for Computer Detection and Correction of Spelling Errors*
.W
The method described assumes that a word
which cannot be found in a dictionary has at most
one error, which might be a wrong, missing or extra letter
or a single transposition.  The unidentified
input word is compared to the dictionary again, testing
each time to see if the words match-assuming
one of these errors occurred.  During a test run on garbled
text, correct identifications were made for
over 95 percent of these error types.
.A
Damerau, F. J.
.I 1113
.T
Computer-Made Perspective Movies as a Scientific and Communication Tool*
.W
It is easy to program the basic transformation
required for a perspective drawing.  This fact
plus the advent of high speed microfilm printers such
as the General Dynamics Electronics S-C 4020 makes
possible perspective movies as the direct output from
a computer.  The programming of such a movie is
briefly described for studying the angular motions of
a satellite containing an attitude control system.
 In the movie, a domino-shaped box represents the satellite
and a sphere with circles of latitude and
longitude represents the earth.  The cost was approximately
three to eight minutes of IBM 7090 time per
one minute of movie.
.A
Zajac, E. E.
.I 1114
.T
Generating a Canonical Prefix Encoding*
.W
Computer programs for generating a minimum-redundancy
exhaustive prefix encoding are described.
 One program generates a Huffman frequency tree, another
determines the structure functions of an encoding,
and a third program assigns codes.
.A
Schwartz, E. S.
Kallick, B.
.I 1115
.T
Randomized Binary Searching With Tree Structure
.W
A more efficient method of using tree structures
is proposed, which utilizers both plus and
minus branches in the search path.  Very significant
gains result when the search key includes alphabetic
characters.
.A
Clampett Jr., H. A.
.I 1116
.T
Tests on a Computer Method for Constructing School Timetables*
.W
A previously proposed computer method for constructing
timetables, based on an iteration involving
Boolean matrices, is described.  In limited tests the
method has successfully produced timetables on
every trial.  References are given which relate the
timetable problem to theorems on matrices of zeros
and ones, and to theorems on bipartite graphs.  Some
problems of applying the method to constructing
timetables in real situations are noted.
.A
Csima, J.
Gotlieb, C. C.
.I 1117
.T
Polyphase Sorting With Overlapped Rewind*
.W
A variation of the polyphase merge technique
of sorting is described which permits one tape
at a time to be rewound while the merge is continued on
the remaining tapes.  The result is the overlapping
of a major portion of the rewind time.  The technique
should be considered whenever a sort is written
to operate on five or more tapes that cannot be read backwards.
 The savings of the overlap method appear
to increase as the number of available tapes is increased.
.A
McAlester, R. L.
.I 1118
.T
FORTRAN Subroutines for Time Series Data Reduction*
.A
MacGowan, R. A.
.I 1119
.T
An Open Letter to X3.4.3 (FORTRAN Standards -- American Association)
.I 1120
.T
"ALCOR Group Representations of ALGOL Symbols,"
Comm. ACM 6 (1963), 597-599. (Corrigenda)
.I 1121
.T
Comments on "A Continued Operation Notation"*
.W
This note is intended to clarify and correct
several points in a recent paper describing some
notations for symbol manipulation by M.P. Barnett [Comm. ACM 6(August, 1963)].
.A
Barnett, M. P.
Gerard, J. M.
Sambles, A. W.
.I 1122
.T
A Note on Some Compiling Algorithms
.W
Two compiling generators for arithmetic expressions
are discussed: one presently in use in
an experimental compiler, and an improvement
suggested by K. Speierman of Burroughs.
.A
Anderson, J. P.
.I 1123
.T
Gauss (Algorithm 209)
.A
Gladfelter, G. W.
.I 1124
.T
Matrix Division (Algorithm 197)
.A
Wells, M.
.I 1125
.T
Syminv2 (Algorithm 150)
.A
Naur, P.
.I 1126
.T
ERF (Algorithm 123)
.A
Barton, S. P.
Wagner, J. F.
.I 1127
.T
Tridiagonal Matrix (Algorithm 122)
.A
Naur, P.
.I 1128
.T
Evaluation of Determinant (Algorithm 41)
.A
Rotenberg, L. J.
.I 1129
.T
Incomplete Beta Function Ratios (Algorithm 222)
.A
Gautschi, W.
.I 1130
.T
Gamma Function (Althm 221)
.A
Gautschi, W.
.I 1131
.T
On Context and Ambiguity in Parsing*
.A
Ross, D. T.
.I 1132
.T
An Extension to ALGOL for Manipulating Formulae*
.A
Perlis, A. J.
Iturriaga, R.
.I 1133
.T
A Programming Package for Some General Modes of Arithmetic*
.A
Brooker, R. A.
.I 1134
.T
Some Effects of the 6600 Computer on Language Structures*
.W
The problem of compiling efficient 6600 codes
prompted the development of an intermediate language
reflecting the structure of the machine, that is more
easily manipulated in improving object program
efficiency.  The subject of this paper is the intermediate
language and methods of manipulating it.
Compilations of a series of arithmetic statements are
discussed.  It is assumed that all functions and
exponentials have been removed from these statements,
and replaced by simple variables.  For purposes
of simplicity the treatment of subscripts is ignored.
A simplified 6600 structure is presented to illustrate
the compiling method.  Several assumptions are made
for purposes of simplification, although there are
cases in which the assumptions are violated in the actual machine.
.A
Allard, R. W.
Wolf, K. A.
Zemlin, R. A.
.I 1135
.T
A General Business-Oriented Language Based on Decision Expressions*
.W
The structure of a digital compute programming
language which covers a wide class of business
and file processing applications is presented.  Such
a structure, based on identifying and incorporating
into a compiler the aspects common to all processes
of such class, permits writing extremely compact
programs, even for comparatively complex applications,
in terms of tables of control expressions which
express only information characteristic of the particular
application.  Furthermore,local changes of
a process (e.g. changes affecting only one of the output
files involved) can be effected by local modifications
in the program (e.g. modification of only one entry of the
tables).  This structure also allows for inexpensive
preparation of loading-speed compilers which translate the
source programs into efficient machine codes.
 The approach adopted here departs from conventional mechanical
language design philosophies.  It stresses
the structural analysis of the class of processes to be represented
in the languages, as opposed to emphasizing
formal (i.e., contents-independent) syntactical definitions.
 It relies exclusively on nonprocedural
representation of process as sets (tables) of relations
between data and results (there are no control
statements such as GO TO, etc.), instead of using procedure
descriptions (which are one-to-one translations
of flowcharts).  Here an invariant pattern of procedure
is identified as characteristic of the class
of all batch file processes.  This new philosophy has
the potential to overcome well-known deficiencies
of other business-oriented languages and fully meets
the requirements set by CODASYL for such languages,
including machine-independence.
.A
Lombardi, L. A.
.I 1136
.T
Beginnings of a Theory of Information Handling*
.A
Steel Jr., T. B.
.I 1137
.T
A Format Language*
.A
Perlis, A. J.
.I 1138
.T
Formalism in Programming Languages*
.A
Iverson, K. E.
.I 1139
.T
FORTRAN IV as a Syntax Language*
.A
Leavenworth, B. M.
.I 1140
.T
"Structural Connections" in Formal Language*
.A
Irons, E. T.
.I 1141
.T
Bounded Context Syntactic Analysis
.A
Floyd, R. W.
.I 1142
.T
An Extension of ALGOL-Like Languages
.A
Rose, G. F.
.I 1143
.T
Analysis of Decay-Type Data*
.W
A comparative study has been made of a variety
of numerical techniques for fitting experimental
data of the decay type by forms involving the sums of
exponentials.  Statistical errors of the fitted
parameters are also calculated.  These methods have been
applied to artificially-generated sets of data
as well as to the results of experiments with radioactive
tracers on both human and animal subjects.
 Results show that the values of the fitted parameters
are very sensitive to variations in the fitting
procedure.  Therefore great care very sensitive to variations
in the fitting procedure.  Therefore great
care must be exercised in identifying such values with
physical constants.  Although the values of functions
derived from these fitted parameters which can definitely
be associated with physical entities are generally
more stable under variations in the fitting techniques,
error bounds can be so large that no great confidence
can be placed even in them.  It would therefore appear
best to select a uniform technique both for running
the experiments and for analyzing the data, and then
to consider as significant only relative results
between one subject and the next.
.A
Worsley, B. H.
.I 1144
.T
Digital Computer Determination of Alpha Source Activity
.W
A technique is described for determining the
activity and homogeneity of an alpha source.
It is believed that the technique, using a digital computer,
has many uses and applications in the field
of nuclear physics. The technique involves computer
manipulation of the digital image of the nuclear
source.  Experimental details are given.
.A
Robbins, D.
Taylor, W. E.
.I 1145
.T
GIT-A Heuristic Program for Testing Pairs
of Directed Line Graphs for Isomorphism*
.W
Given a pair of directed line graphs, the problem
of ascertaining whether or not they are isomorphic
is one for which no efficient algorithmic solution is known.
 Since a straightforward enumerative algorithm
might require 40 years of running time on a very high
speed computer in order to compare two 15-node
graphs, a more sophisticated approach seems called
for.  The situation is similar to that prevailing
in areas such as game-playing and theorem-proving, where
practical algorithms are unknown (for the interesting
cases), but where various practical though only partially
successful techniques are available.  Git-Graph
Isomorphism Tester-incorporates a variety of processes
that attempt to narrow down the search for an
isomorphism, or to demonstrate that none exists.  No one
scheme is relied upon exclusively for a solution,
and the program is designed to avoid excessive computation
along fruitless lines.  GIT has been written
in the COMIT language and successfully tested on the IBM 7090.
.A
Unger, S. H.
.I 1146
.T
An Efficient Composite Formula for Multidimensional Quadrature
.W
A (2s+1)-point second-degree quadrature formula
for integration over an s-dimensional hyper-rectangle
is presented.  All but one of the points lie on the
surface with weights of opposite sign attached to
points on opposite faces.  When a large volume is subdivided
into congruent rectangular subdivisions,
only one point is required in each interior subdivision
to achieve second-degree accuracy.
.A
Thacher Jr., H. C.
.I 1147
.T
On the Numerical Solution of Boundary Value Problems
for Linear Ordinary Differential Equations*
.W
A numerical method is presented for the solution
of boundary value problems involving linear
ordinary differential equations.  The method described
is noniterative and makes use of any one-step
numerical integration scheme to reduce the problem from
one of boundary values to one of initial values.
 Comments are made concerning some numerical results
of applying the method to a specific problem.  In
addition an extension of the algorithm described
to more general problems is discussed.
.A
Day, J. T.
Collins II, G. W.
.I 1148
.T
An Example in "Significant-Digit" Arithmetic*
.W
Different methods of handling the summing process
for the geometric series are shown to give
results indicating widely differing significances when carried
out in a machine incorporating "significant-digit"
arithmetic.
.A
Miller, R. H.
.I 1149
.T
GARGOYLE , A Language for Compiler Writing*
.A
Garwick, J. V.
.I 1150
.T
A Fortran Post-Mortem Procedure
.A
Kahan, W.
Leppik, J. J.
.I 1151
.T
A Note on Multiplying Boolean Matrices II
.A
Comstock, D. R.
.I 1152
.T
Floating-Point Arithmetic with 84-Bit Numbers
.W
A classic and straightforward technique is
presented which is not limited to the size or type
of number representation used or multiple precision arithmetic.
.A
Gregory, R. T.
Raney, J. L.
.I 1153
.T
A Fast Procedure for Generating Normal Random Variables*
.W
A technique for generating normally distributed
random numbers is described.  It is faster
than those currently in general use and is readily
applicable to both binary and decimal computers.
.A
Marsaglia, G.
MacLaren, M. D.
Bray, T. A.
.I 1154
.T
Multi-Tape and Infinite-State Automata -- A Survey
.W
A survey of machines which are more powerful
than finite automata and less powerful than general
Turing machines is presented.  It is felt that the machines
in this category are as closely related to
digital computers as either the finite automata or the
unrestricted Turing machines.  Intermediate machines
can be created by adjoining on infinite-state memory
to a finite-state machine and then performing any
or all of the following: (1) restrict the manner in
which the unbounded portion of the memory can be
accessed, (2) bound the number of steps allowed for a
computation by some increasing recursive function
of the length of the input, (3) restrict the total amount
of memory available in the same manner.  Examples
from all three classes and their properties are discussed.
.A
Fischer, P. C.
.I 1155
.T
Experiments with a Deductive Question-Answering Program
.W
As an investigation in artificial intelligence,
computer experiments on deductive question-answering
were run with a LISP program called DEDUCOM, an acronym
for DEDUctive COMmunicator. When given 68 facts,
DEDUCOM answered 10 questions answerable from the facts.
 A fact tells DEDUCOM either some specific information
or a method of answering a general kind of question.
 Some conclusions drawn in the article are: (1)
DEDUCOM can answer a wide variety of questions.  (2)
A human can increase the deductive power of DEDUCOM
by telling it more facts.  (3) DEDUCOM can write very
simple programs (it is hoped that this ability
is the forerunner of an ability to self-program, which
is a way to learn).  (4)DEDUCOM's search procedure
at present has two bad defects: some questions answerable
from the given facts cannot be answered and
some other answerable questions can be answered only if
the relevant facts are given in the "right" order.
 (6) At present, DEDUCOM's method of making logical deductions
in predicate calculus has two bad defects:
some facts have to be changed to logically equivalent ones
before being given to DEDUCOM, and some redundant
facts have to be given to DEDUCOM.
.A
Slagle, J. R.
.I 1156
.T
Hankel Function (Algorithm 124 [S17])
.A
Reilly, G. A.
.I 1157
.T
Procedure for the Normal Distribution Functions (Algorithm 272 [S15])
.A
MacLaren, M. D.
.I 1158
.T
Program Structures for Parallel Processing
.W
Constructs for organizing and explicating parallel
program segments are discussed as extensions
to ALGOL 60.  The constructs serve as meta-commands and
are motivated by equipment having multiprocessing
capability.
.A
Anderson, J. P.
.I 1159
.T
Machine Independence: Its Technology and Economics
.W
A survey is offered of techniques for transferring
programs, and especially compilers, from
one computer to another.  Of the methods examined, the
"bootstrap" technique is singled out for detailed
discussion, with emphasis on its economics. The considerations
that determine the applicability of bootstrapping
in any specific case are discussed, and an attempt
is made to assign appropriate qualitative weights
to them.  Finally, reasons are given for believing that the
machine-independence problem is being substantially
diminished by current trends in computer design, and
that it is this process of convergence in hardware
design rather than any foreseeable software developments
that will lead to its satisfactory resolution.
.A
Halpern, M. I.
.I 1160
.T
CAT: A 7090-3600 Computer-Aided Translation
.W
A semi-automatic translation system has been implemented
which converts 7090 FAP language programs
into 3600 assembly language.  The input to the system
is a FAP program deck which has been specially
prepared for translation by the user.  The output consists
of the translated COMPASS language program
together with a comprehensive diagnostic listing which the
user must analyze in order to verify any questionable
areas of the translation.  The translation processor
consists of three distinct phases: an assembly of
the FAP program, a comprehensive analysis of the assembled
code with particular regard to the actions
of instructions upon other instructions and upon data,
and finally the output pass which generates the
COMPASS program in the form of macro instructions.
.A
Wilson, D. M.
 Moss, D. J.
.I 1161
.T
1401 Compatibility Feature on the IBM System/360 Model 30
.W
The "second generation" of stored-program computers,
of which IBM 1400 series was a part, brought
EDP into the mass market for the first time on a large
scale.  As this era unfolded, rapid changes in
technology led to rapid obsolescence of data processing
equipment.  Program written for a particular
system required tedious conversion as incompatible new
machines came into use.  The IBM System/360 has
been designed with the conversion problem specifically
in mind.  One of the conversion aids available
on the Model 30 is the 1401 compatibility feature.  This
feature, in conjunction with other aids, permits
a smooth and inexpensive transition to optimum use of the new system.
.A
McCormack, M. A.
Schansman, T. T.
Womack, K. K.
.I 1162
.T
An Assembly Language for Reprogramming
.W
Complete reprogramming of compiler language programs
is seldom necessary.  It is assembly language
programs which present the greatest difficulty.  Assembly
languages generally provide a one-for-one translation
from a symbolic to a numeric version of a program, that
is, from assembly language to machine language.
 The meta-language presented here can be used to specify
the mapping of any language which conforms to
a canonical list form into an arbitrary stream of bits.
 This bit stream may be treated as a machine
language program, a character stream, or whatever else
the user might desire.  Thus, this meta-language
can be used to map from one assembly language into another
or from the assembly language for one machine
into the machine language of another.
.A
Graham, M. L.
Ingerman, P. Z.
.I 1163
.T
Philco/IBM Translation at Problem-Oriented, Symbolic and Binary Levels
.W
A translation system has been developed to
eliminate most of the effort formerly required to
reprogram Philco 2000 series codes for IBM 7094 operation.
 Experience with this system is limited but
highly successful encouraging application of the
techniques to other source and object languages.
.A
Olsen, T. M.
.I 1164
.T
Emulation of Large Systems
.W
The conversion problem and a new technique
called emulation are discussed.  The technique of
emulation is developed and includes sections on both the
Central Processing Unit (CPU) and the Input/Output
unit (I/O).  This general treatment is followed by three
sections that describe in greater detail the
implementation of compatibility features using the emulation
techniques for the IBM 7074, 7080 and 7090
systems on IBM System/360.
.A
Tucker, S. G.
.I 1165
.T
The Spectra 70/45 Emulator for the RCA 301
.W
The RCA 301 Emulator System is supplied with
the Spectra 70/45 as a reprogramming aid.  It
allows an RCA 301 object program to be run on the Spectra
70/45 without necessitating changes in the
RCA 301 object code.  Execution rates are considerably
better than traditional simulation.  The Emulator
provides an increase in throughput capacity for the
301 user on the Spectra 70/45.  The Emulator makes
use of both hardware micro-program routines and
software routines to accomplish its function.
.A
Benjamin, R. I.
.I 1166
.T
A Use of Macros in Translation of Symbolic
Assembly Language of One Computer to Another
.W
A set of macro-operations has been prepared
to assist in translating IBM 7090 symbolic assembly
language programs to IBM 7040 machine language programs.
 This set, inserted at the beginning of the
7090 symbolic deck, treats incompatible instruction mnemonics
as macro-instructions to produce equivalent
7040 instruction sets.  Incompatible instructions are
categorized into basic operational classes which
can be expressed by a single basic skeleton.  Several levels
of macro calls are required to supply arguments
to the basic skeleton for each particular instruction.
 Modification at execution time of the address
or tag of an incompatible instruction requires incorporation
of an address-tag equivalent.  I/O is handled
by generating calls to I/O simulation subroutines.
.A
Dellert Jr., G. T.
.I 1167
.T
On the Translation of Machine Language Programs
.W
Automatic translation of machine language
programs is becoming a highly desirable goal with
the advent of new large-scale computers.  The pitfalls that
make it difficult to achieve completely automatic
translations are analyzed, and it is shown that these are
primarily of a semantic nature.  A semi-automatic
procedure for resolving semantic problems is suggested.
.A
Gaines, R. S.
.I 1168
.T
Across Machine Lines in COBOL
.W
The production of a large, file-maintenance-and-retrieval
program system written in COBOL is
described.  The COBOL language was used specifically to
enable the system to operate on three IBM computers.
.A
Fredericks, D. S.
Warburtin, C. R.
.I 1169
.T
An Algorithm for Minimizing Backboard Wiring Functions
.W
A partially exhaustive algorithm is presented
for solving the following problem arising from
automatic layout of a computer.  Given an ordered set
E1, E2,..., EN of N computer components, for each
permutation of the elements E1, E2.., EN, there is attached
a value of an integer function F.  The algorithm
finds a local minimum of F by evaluating the set {Delta
F} of the increments corresponding to a certain
set of exchanges of two elements.Then the exchange
corresponding to the least negative increment of
{Delta F} is performed.  The process is iterated and stopped
when the set of the increments is a positive
or empty set, which, it is proved, corresponds to a
minimum.  The procedure is similar to the Downhill
Method for finding the minimum of a real function F(P),
and can be applied to other placement problems.
 Experimental results are presented with backboards formed
by many elements and different initial placements.
.A
Pomentale, T.
.I 1170
.T
Analyzing English Syntax with a Pattern-Learning Parser
.W
A dependency analysis system based on pattern
recognition and learning logic was developed
to infer word classes and rules of syntactic combination
from experience with text which had been analyzed.
 The characteristics used to form word classes are the
depth in the dependency tree of each word, the
direction of its governor and the same features for
each of its immediate neighbors. Syntactic rules
of combination show the relation of a word to its governor
in the depth pattern of the sentence.  The
system was tested on 400 elementary basic English sentences
including 300 used earlier by Knowlton in
a different learning parser of all 400 sentences.  After
experience with 300 sentences it was able to
generalize with 77 percent accuracy to the next 100.
 In accumulative learning trials after the first
200 sentences it averaged a probability of .9 for accurately
parsing each new sentence it encountered.
 It was concluded that the system is adequate for learning
to parse the bulk of basic English but that
further development is required before conclusions about
its application to ordinary English can be stored.
 The system is operational and available on
the ARPA/SDC time-shared computing system.
.A
McConlogue, K.
Simmons, R. F.
.I 1171
.T
A Comparison of the Primal-Simplex and Primal-Dual
Algorithms for Linear Programming
.W
A statistical comparison of the primal-dual
and the more commonly used primal-simplex algorithm
for solving linear programming problems has been made under
the assumption of starting with a full artificial
basis.  Under these conditions the primal-dual method
shows a statistically significant superiority on
randomly generated problems.  It has also been found, via
a regression analysis, that the relevant parameters
in determining the difference in the number of iterations
between the algorithms is not only the number
of constraints and the number of variables but
also the ratio of the latter to the former.
.A
Mueller, R. K.
Cooper, L.
.I 1172
.T
Conversion of Limited-Entry Decision Tables to Computer Programs
.W
Decision tables are useful for describing a
set of complex decision rules based on given sets
of conditions.  Algorithms that can efficiently convert
the tables into computer programs will extend
the usefulness of decision tables to computer users.
 Two such algorithms, based on work done by M. S.
Montalbano, are described and extended here to handle
dashes and ELSE-decision rules.  The first algorithm
minimizes the computer storage space required for the
resultant program, the second minimizes computer
running time. During the conversion process, both pinpoint
any contradictions or redundancies among the
rules in a table.
.A
Pollack, S. L.
.I 1173
.T
The Performance of a System for Automatic Segmentation
of Programs Within an ALGOL Compiler (GIER
ALGOL)
.W
The GIER ALGOL compiler makes use of an automatic
system for handling the transfers of program
segments from the drum store to the core store at program
execution time.  The logic of this system is
described. The performance of the system is discussed,
primarily on the basis of execution times related
to two specific programs.  This discussion concludes with
an assessment of the potential gains of various
ways of improving the system.
.A
Naur, P.
.I 1174
.T
Inverse Permutation (Algorithm 250 [G6])
.A
Medlock, C. W.
.I 1175
.T
Quickersort (Algorithm 271 [M1])
.A
Scowen, R. S.
.I 1176
.T
Finding Eigenvectors by Gaussian Elimination (Algorithm 270 [F2])
.A
Newhouse, A.
.I 1177
.T
Determinant Evaluation (Algorithm 269 [F3])
.A
Pfann, J.
.I 1178
.T
ALGOL 60 Reference Language Editor (Algorithm 268 [R2])
.A
McKeeman, W. M.
.I 1179
.T
PUFFT-The Purdue University Fast FORTRAN Translator
.W
A core resident, compile-and-go system designed
for the IBM 7090/7094 computer is described.
 In little more than half of the 32k word core memory
PUFFT provides a monitor for job sequencing, a
translator for the full FORTRAN IV language, the FORTRAN
subroutine library, an input--output system
for use at compile time and at execute time, and a rather
elaborate diagnostic message writing routine.
 Batches of small- and medium-sized FORTRAN IV source
language programs are processed at very high speeds.
 Language compatibility has been maintained so that
programs may be debugged in the PUFFT system and
then recompiled and run in the IBJOB-IBFTC system supplied by the manufacturer.
.A
Rosen, S.
Spurgeon, A.
Donnelly, J. K.
.I 1180
.T
AXLE: An Axiomatic Language for String Transformations
.W
AXLE is a language designed for data manipulation.
 Data arranged in a linear form in a workspace
is transformed according to a table of axioms, called imperatives.
 A transformation consists of a matching
procedure, which decides where an imperative is applicable,
and a replacement procedure that modifies
that part of the workspace.  Imperatives are applied
in accordance with definitions of symbolic terms,
presented systematically in an assertion table.  The
process of definition includes the special case
of recursive assertions.  Several complete programs
of imperatives are given to show a few applications
of the language.
.A
Cohen, I.
Wegstein, J. H.
.I 1181
.T
A Simple Data Transmission System Using the Office Telephone
.W
A method has evolved for transmitting data of
a type originating in many laboratory situation
direct to a central computer.  The method requires almost
no specialized equipment and uses any ordinary
telephone on a "callup" basis.  Present applications
include cardiac-output calculations, radio-activity
tracer studies and neurophysiology time-sequence studies of nerve impulses.
.A
Neilsen, I. R.
.I 1182
.T
Contextual Correlates of Synonymy
.W
Experimental corroboration was obtained for
the hypothesis that the proportion of words common
to the contexts of word A and to the contexts of word
B is a function of the degree to which A and B
are similar in meaning.  The shapes of the functions,
however, indicate that similarity of context is
reliable as criterion only for detecting pairs
of words that are very similar in meaning.
.A
Rubenstein, H.
Goodenough, J. B.
.I 1183
.T
A Note on the Use of a Digital Computer
for Doing Tedious Algebra and Programming
.W
A special purpose compiler was written with
FORTRAN II language and made possible the writing
of very long programs by the computer.  The procedure is
based on a straight-forward use of FORMAT statements
for generating machine-written programs.
.A
Veronis, G.
.I 1184
.T
A Fast Storage Allocator
.W
A fast storage bookkeeping method is described
which is particularly appropriate for list-structure
operations and other situations involving many sizes
of blocks that are fixed in size and location.
 This scheme, used in the LLLLLL or L6 (Bell Telephone Laboratories
Low-Level List Language), makes available
blocks of computer registers in several different sizes:
the smaller blocks are obtained by successively
splitting larger ones in half, and the larger blocks are reconstituted
if and when their parts are simultaneously
free.
.A
Knowlton, K.C.
.I 1185
.T
A program to Solve the Pentomino Problem by the Recursive Use of Macros
.W
A coding technique is described in which certain
macro-instructions are given lists as arguments
and are thereby used recursively.  The discussion covers
primarily an example in which the technique
is used to solve the pentomino problem-the problem of
fitting 12 pentominos without overlapping into
a plane area formed of 60 elemental squares.
.A
Fletcher, J. G.
.I 1186
.T
Recursive Solution of a Class Of Combinatorial Problems: An Example
.W
Combinatorial problems requiring the selection
of n elements from a set of m elements may be
solved by a recursion process analogous to that for
computing binomial coefficients.  Several specific
problems are analyzed, the general technique is exposed,
and an ALGOL program is developed for one of
the problems.
.A
Lynch,W. C.
.I 1187
.T
Note on an ASCII-Octal Code Table (Standards)
.A
Crosby, W. S.
.I 1188
.T
An ALGOL-like Computer Design Language
.W
The idea of constructing a computer design
language by making use of an ALGOL-like programming
language is presented.  A computer designer can benefit
from using a design language at a higher level
just as a computer user can benefit from a higher level
programming language.  The purposes and requirements
of the design language are enumerated.  To achieve most
of the purposes a translator is required to translate
a design of computer logic into a set of Boolean equations.
 The design language is presented in terms
of vocabulary, statements, sequences and microprogram.
 Included are examples of identifiers, expressions
with both unary and binary operators, declaration statements,
transfer statements, terminal statements,
exchange statements, if statements, do statements, go
to statements, several sequences and a microprogram.
.A
Chu, Y.
.I 1189
.T
Random Normal Deviate (Algorithm 267 [G5])
.A
Pike, M. C.
.I 1190
.T
Pseudo-Random Numbers (Algorithm 266 [G5])
.A
Pike, M. C.
Hill, I. D.
.I 1191
.T
Find Precedence Functions (Algorithm 265 [L2])
.A
Wirth, N.
.I 1192
.T
Interpolation in a Table (Algorithm 264 [E1])
.A
Stafford, J.
.I 1193
.T
Gomory 1 (Algorithm 263 [H])
.A
Langmaack, H.
.I 1194
.T
Establishment of the ACM Repository and Principles
of the IR System Applied to its Operation
.W
The history of the establishment of the ACM Repository
at the Moore School, University of Pennsylvania,
is reviewed briefly.  Two principles are presented as
paramount in the provision of information services:
(1) easy accessibility to the information files by users
unfamiliar with file organization, and (2) value
of service exceeding user costs.  These principles serve
as guides in mechanizing the ACM Repository.
 The main features of the information system are direct
user access via on-line teletypewriter console,
direct user access to all details of the system organization,
unrestricted and expandable search vocabulary,
user access through many facets of document indexing,
and stochastic search through linked index terms
and other file relationships.  The first contribution
to the ACM Repository consisted of 315 documents,
relating primarily to early research on compilers.  These
documents have been cataloged and indexed and
the catalog is scheduled to appear in Computing Reviews.
 The indexing system is described in detail.
 The Main Catalog is used to describe the documents,
and inverted lists are provided by the Repository
system for retrieval by concept coordination.
.A
Rubinoff, M.
White Jr., J. F.
.I 1195
.T
UPLIFTS-University of Pittsburgh Linear File Tandem System
.W
A series of computer programs has been developed
and is now operational for processing the
National Aeronautics and Space Administration linear file
system on an IBM 1401-7090 combined data processing
system.  The program are note-worthy in that they create
fixed length logical records and fixed length
blocks from variable length source data, and format
the output for optimization of processing on the
IBM 7090 system.  The programs are completely self-checking
and test for both validity and accuracy of
the input materials as provided by the National
Aeronautics and Space Administration.
.A
Canter, J. D.
Donaghey, C. E.
.I 1196
.T
Applications of Differential Equations in General Problem Solving
.W
A large class of problems leading to digital
computer processing can be formulated in terms
of the numerical solution of systems of ordinary differential
equations.  Powerful methods are in existence
for the solution of such systems.  A good general purpose
routine for the solution of such systems furnishes
a powerful tool for processing many problems.  This is
true from the point of view of ease of programming,
ease of debugging, and minimization of computer time.
 A number of examples are discussed in detail.
.A
Klopfenstein, R. W.
.I 1197
.T
Finding Zeros of a Polynomial by the Q-D Algorithm
.W
A method which finds simultaneously all the zeros
of a polynomial, developed by H. Rutishauser,
has been tested on a number of polynomials with real
coefficients.  This slowly converging method (the
Quotient-Difference (Q-D) algorithm) provides starting
values for a Newton or a Bairstow algorithm for
more rapid convergence.  Necessary and sufficient conditions
for the existence of the Q-D scheme are
not completely known; however, failure may occur when
zeros have equal, or nearly equal magnitudes.
Success was achieved, in most of the cases tried, with
the failures usually traceable to the equal magnitude
difficulty.  In some cases, computer roundoff may result
in errors which spoil the scheme.  Even if the
Q-D algorithm does not give all the zeros,
it will usually find a majority of them.
.A
Henrich, P.
Watkins, B. O.
.I 1198
.T
Solution of a Problem in Concurrent Programming Control
.W
A number of mainly independent sequential-cyclic
processes with restricted means of communication
with each other can be made in such a way that at any
moment one and only one of them is engaged in the
"critical section" of its cycle.
.A
Dijkstra, E. W.
.I 1199
.T
A Computer Center Simulation Project
.W
Today's computation centers are based on rapidly
changing technologies of hardware and software
systems.  It is difficult, therefore, to base decisions
on experience; in most instances, the benefits
of comparable experience for a given problem situation
are not available.  In this paper, a mathematical
model of the Lockheed Central Computer Center is formulated
that describes the operation of a computation
center in terms of information nets, decision processes,
and control functions.  Experiments performed
with this model, the results of the experiments,
and the application of the results are discussed.
.A
Hutchinson, G. K.
.I 1200
.T
On Reversible Subroutines and Computers that Run Backwards
.W
A computer design is describe which permits
subroutines to be executed backward as well as
forward, either with their instructions unchanged or
replaced with conjugate instructions.  It is shown
that using this concept a number of new subroutine types
can be developed with rather unusual properties.
 Since these properties are analogous to certain matrix
operations, a parallel nomenclature is suggested
for their classification.
.A
Reily, E. D.
Federighi, F. D.
.I 1201
.T
Generation of Permutations in Lexico-Graphical
Order (Algorithm 202 [G6])
.A
Elliott, R. W.
.I 1202
.T
Normal Random (Algorithm 200 [G5])
.A
Pike, M. C.
.I 1203
.T
Normdey (Algorithm 121 [G5])
.A
Pike, M. C.
.I 1204
.T
Character Structure and Character Parity Sense for
Serial-by-Bit Data Communication in the American
Standard Code for Information Interchange (Proposed American Standard)
.I 1205
.T
An Undergraduate Program in Computer Science-Preliminary Recommendations
.A
A Report from the ACM Curriculum Committee on Computer Science
.I 1206
.T
The Self-Judgment Method of Curve Fitting
.W
A computer-oriented method for processing and
communicating numerical data is described.  The
Instrument Reliability Factors (IRF), which exactly
define the limits of reliability of each measured
item of information, are used to compute the Maximum
Permitted Error (MPE) associated with each values
of each ordinate.  The Self-Judgment Principle (SJP)
is used to discard wrong information and to compute
mean values of the parameters and their MPE's in terms
of the IRF.  Data compatibility tests with any
number of different equations can be made quickly.
Otherwise intractable problems are easily solved,
and the design of many experiments is greatly simplified.
 The computational and mathematical techniques
used to reduce bias in the SJP are discussed.  Inadequacies
in the statistical and graphical methods
of curve fitting are noted.
.A
DeMaine, P. A. D.
.I 1207
.T
Remarks on Simulation of Boolean Functions
.A
Dodd, G. G.
.I 1208
.T
Simulation of Computer Logic by Fortran Arithmetic
.A
Weingarten, F. W.
.I 1209
.T
Negative and Zero Subscripts in Fortran II Programming for the IBM 1620
.A
Garber, M. S.
.I 1210
.T
File-Handling Within FORTRAN
.W
This note describes some FORTRAN subroutines
to facilitate handling of tape files.  They allow
symbolic naming of information files, without violating
the casual scientific programmer's idea of simplicity.
 Some comments on two years use of these subroutines are given.
.A
Harrison, M. C.
.I 1211
.T
A Note on Storage of Strings
.W
A method for storing strings is described which
uses blocks of indefinite size, and is therefore
completely dynamic.  Its relation to similar schemes is discussed.
.A
Berztiss, A. T.
.I 1212
.T
Non-linear Extrapolation and Two-Point Boundary Value Problems
.W
It is suggested that the convergence properties
of the usual Picard successive approximation
scheme may be improved through use of non-linrar extrapolation
techniques.  A numerical example is provided.
.A
Bellman, R.
Kagiada, H.
Kalba, R.
.I 1213
.T
Dynamic Format Specifications
.W
The use and implementation of two new FORTRAN
format conversions are discussed.  These format
types give the FORTRAN programmer control of input/output
specifications at execution time.
.A
Ranelletti, J. E.
.I 1214
.T
Some Experiments in Algebraic Manipulation by Computer
.W
A set of subroutines to allow algebraic manipulations
on the IBM 7094 computer has been written
a List Processor, SLIP.  A series of four problems of increasing
difficulty were solved using these routines.
.A
Lapidus, A.
Goldstein, M.
.I 1215
.T
Some Techniques Used in the ALCOR ILLINOIS 7090
.W
An ALGOL compiler has been written by the
ALCOR group for the IBM 7090.  Some little known
but significant techniques in compiler writing, together
with organizational details of this compiler,
are described.  Timing estimates and an indication
of compiler requirements are also given.
.A
Gries, D.
Paul, M.
Wiehle, H. R.
.I 1216
.T
Symbolic Derivatives Without List Processing, Subroutines, or Recursion
.W
A routine has been developed which computes and
prints out the symbolic derivative of an absolutely
continuous elementary function of one or several variables.
 No use is made of list-processing languages.
 The chain rule is applied and the result is edited to
produce results as elegant and efficient as those
obtained by hand computation.  A subset may be imbeded
in a formula translator to introduce a differentiation
operator into an "algebraic" programming language.
.A
Smith, P. J.
.I 1217
.T
Map of Partitions into Integers (Algorithm 264 [A1])
.A
McKay, J. K. S.
.I 1218
.T
Partition Generator (Algorithm 263 [A1])
.A
McKay, J. K. S.
.I 1219
.T
Number of Restricted Partitions of N (Algorithm 262 [A1])
.A
McKay,J. K. S.
.I 1220
.T
9-J Symbols (Algorithm 261 [Z])
.A
Gunn, J. H.
.I 1221
.T
6-J Symbols (Algorithm 260 [Z])
.A
Gunn, J. H.
.I 1222
.T
Legendre Functions for Arguments Larger Than One (Algorithm 259 [S16])
.A
Gautschi, W.
.I 1223
.T
High Speed Compilation of Efficient Object Code
.W
A three-pass compiler with the following properties
is briefly described:  The last two passes
scan an intermediate language produced by the preceding
pass in essentially the reverse of the order
in which it was generated, so that the first pass is the
only one which hasto read the bulky problem-oriented
input.  The double scan, one in either direction, performed
by the first two passes, allows the compiler
to remove locally constant expressions and recursively
calculable expressions from loops and to do the
important part of common subexpression recognition.
 Optimization such as the effective use of index
registers, although as important, is not discussed since
the object code which would be most efficient
is highly machine dependent.  The discussion is in terms
of a FORTRAN-like language, although the technique
is applicable to most algebraic languages.
.A
Gear, C. W.
.I 1224
.T
Determining a Computing Center Environment
.W
An investigation is described in which several
generally unavailable parameters descriptive
of a computing center environment are obtained.  The
actual data collection and reduction is described,
and the results of one month of this collection are tabulated and summarized.
.A
Rosin, R. F.
.I 1225
.T
The Predictive Analyzer and a Path Elimination Technique
.W
Some of the characteristic features of a predictive
analyzer, a system of syntactic analysis
now operational at Harvard on and IBM 7094, are delineated.
 The advantages and disadvantages of the
system are discussed in comparison to those of an immediate
constituent analyzer, developed at the RAND
Corporation with Robinson's English grammar.  In addition,
a new technique is described for repetitive
path elimination for a predictive analyzer, which can
now claim efficiency both in processing time and
core storage requirement.
.A
Kuno, S.
.I 1226
.T
The Organization of Structured Files
.W
A data file is an integral part of a data processing
system.  In many systems, the selection
of an organization for the data within the file can
be critical to the system's operating efficiency.
 This paper provides the systems designer with an information
source which describes ten techniques that
may be employed for organizing structured data.  The
characteristics of the organizations described are
application independent, thus providing the designer with
a reference which allows him to limit the number
of file organizations he must consider for his system.
.A
Dzubak, B. J.
Warburton, C. R.
.I 1227
.T
Transport (Algorithm 258 [H])
.A
Bayer, G.
.I 1228
.T
Treesort 3 (Algorithm 245 [M1])
.A
Abrams, P. S.
.I 1229
.T
Random Permutation (Algorithm 235 [G6])
.A
Pike, M. C.
.I 1230
.T
Method for Hyphenating at the End of a Printed Line
.W
A description of a method of hyphenation is
presented as a result of application of several
general rules.  The character sets considered by the
routine and the method are briefly outlined.
.A
Rich, R. P.
Stone, A. G.
.I 1231
.T
Peephole Optimization
.W
Redundant instructions may be discarded during
the final stage of compilation by using a simple
optimizing technique called peephole optimization.
The method is described and examplesare given.
.A
McKeeman, W. M.
.I 1232
.T
Representation of the Standard ECMA 7-Bit
Code in Punched Cards (ECMA Standard)
.I 1233
.T
Conventions for the Use of Symbols in the Preparation
of Flowcharts for Information Processing
Systems (A Standard Working Paper)
.W
This paper is intended as an outline of the
various conventions which are being considered
for the use of flowcharts for information processing
systems.  The conventions are applied to the use
of the symbols appearing in the proposed American Standard
Flowchart Symbols and not with the symbols
per se.
.I 1234
.T
The Structure of Yet Another ALGOL Compiler
.W
A high-speed "top down" method of syntax analysis
which completely eliminates "back-up" of
the source string has been implemented in a convenient
macro-language.  A technique of  simulation at
compile time of the use of a conventional run-time stack
enables the generation of code for expressions
which minimizes stores, fetches and stack-pointer motion
at run time, while properly trating recursion
and side effects of procedures.  Block structure and
recursion are handled without need for interpretive
methods at run times.  The "context problem" in the transmission
to recursive procedures of parameters
"called by name" is solved in a manner which permits the
handling of the common cases of simple expressions
and array identifiers with particular efficiency.
.A
Kanner, H.
Kosinski, P.
Robinson, C. L.
.I 1235
.T
A Stochastic Approach to the Grammatical Coding of English
.W
A computer program is described which will
assign each word in an English text to its form
class or part of speech.  The program operates at relatively
high speed in only a limited storage space.
 About half of the word-events in a corpus are identified
through the use of a small dictionary of function
words and frequently occurring lexical words.  Some suffix
tests and logical-decision rules are employed
to code additional words.  Finally, the remaining words
are assigned to one class or another on the basis
of the most probable form classes to occur within the already
identified contexts.  The conditional probabilities
used as a basis for this coding were empirically derived
from a separate hand-coded corpus.On preliminary
trials, the accuracy of the coder was 91% to 93%, with
obvious ways of improving the algorithm being
suggested by an analysis of the results.
.A
Stolz, W. S.
Tannenbaum, H.
Carstensen, F. V.
.I 1236
.T
The SMART Automatic Document Retrieval System-An Illustration
.W
A fully automatic document retrieval system
operating on the IBM 7094 is described.  The system
is characterized by the fact that several hundred different
methods are available to analyze documents
and search requests.  This feature is used in the retrieval
process by leaving the exact sequence of
operations initially unspecified, and adapting the
search strategy to the needs of individual users.
 The system is used not only to simulate an actual operating
environment, but also to test the effectiveness
of the various available processing methods.  Results obtained
so far seem to indicate that some combination
of analysis procedures can in general be relied upon to
retrieve the wanted information.  A typical search
request is used as an example in the present report to illustrate
systems operations and evaluation procedures.
.A
Salton, G.
Lesk, M. E.
.I 1237
.T
Conversion of Decision Tables To Computer Programs
.W
Several translation procedures for the conversion
of decision tables to programs are presented
and then evaluated in terms of storage requirements,
execution time and compile time.  The procedures
are valuable as hand-coding guides or as algorithms for
a compiler.  Both limited-entry and extended-entry
tables are analyzed.  In addition to table analysis,
the nature of table-oriented programming languages
and features is discussed.  It is presumed that the reader
is familiar with the nature of decision tables
and conventional definitions.
.A
Press, L. I.
.I 1238
.T
A Technique for Integrated Reports from a Multi-run System
.W
The requirements of a requisition accounting
system for the San Francisco Overseas Supply Agency
(OSA) included exception reporting to OSA itself.  The simultaneous
satisfaction of the reporting requirement
and the accounting requirements posed definite problems
in system design, particularly the handling of
the reporting function.  A practical and satisfactory
solution was developed by expanding the basic system
with two tailored service runs for report production.
 These two runs permitted a final system that was
easier to debug, easy to maintain, efficient in production
and responsive to the changing requirements
of OSA.
.A
Budea, N.
Kamena, J. G.
Kamena, R. M.
.I 1239
.T
Graycode (Algorithm 246 [Z])
.A
Allen, W. D.
.I 1240
.T
Transport (Algorithm 258 [H])
.A
Bayer, G.
.I 1241
.T
Havie Integrator (Algorithm 257 [D1])
.A
Kubik, R. N.
.I 1242
.T
Modified Graeffe Method (Algorithm 256 [C2])
.A
Grau, A. A.
.I 1243
.T
Testing the Understanding of the Difference Between
Call by Name and Call by Value in ALGOL 60
.A
Weil, R. L.
.I 1244
.T
Bit Manipulation in Fortran Language
.A
Tobey, G. D.
.I 1245
.T
A Fortran n-Ary Counter
.A
Kent, W.
.I 1246
.T
Deeply Nested Iterations
.A
Korphage, R. R.
.I 1247
.T
An Operating Environment for Dynamic-Recursive
Computer Programming Systems
.W
Presented in this paper is a brief nontechnical
introduction to OEDIPUS, a computer programming
system which can serve as an operating environment for
dynamic and/or recursive programs and programming
systems.  The available services include dynamic allocation
of storage for contiguous blocks of arbitrary
size, input and output for a hierarchy of data types,
a public pushdown list for automatic recursive
programming, a rudimentary compiler for subroutine
communication and bookkeeping, and debugging aids.
.A
Brown, W. S.
.I 1248
.T
On the Automatic Simplification of Computer Programs
.W
Presented in this paper is the problem of writing
a program which would examine any other program
and perform such simplifications on it as can be detected
from the argument-program's form alone, without
having any knowledge of what it is supposed to do.
.A
Nievergelt, J.
.I 1249
.T
 Recorded Magnetic Tape for Information Interchange
(200 CPI, NRZI) (On the Revised Proposed
American Standard)
.I 1250
.T
Graphic Symbols for Problem Definition
and Analysis-A Standards Working Paper
.I 1251
.T
American Standard and IFIP/ICC Vocabularies compared
.W
The "Proposed American Standard Vocabulary of
Information Processing" and the "IFIP/ICC Vocabulary
of Terms Used in Information Processing" are analyzed and compared.
.A
Traub, J. F.
.I 1252
.T
Symbolic Notations for Statistical Tables
and an Approach Towards Automatic System Design
.W
The preparation of statistical tables is an
important function of the data processing systems
of some organizations, and a symbolic notation for the
description of tables has been shown to be a useful
aid to documentation.  Such a notation also provides
the first step towards making automatic a tedious
and time-consuming part of system design and programming
in many computer applications.  One notation
is described and suggestions are made for the implementation of the larger goal.
.A
Smith, B. W.
.I 1253
.T
QUIKSCRIPT-A SIMSCRIPT- Like Language for the G-20
.W
QUIKSCRIPT is a simulation language based on
SIMSCRIPT and programmed entirely in an algebraic
language, 20-GATE.  The QUIKSCRIPT language, its internal
implementation, and major differences between
QUIKSCRIPT and SIMSCRIPT are presented.  This paper is
not a programming guide to the language, but rather
an attempt to present its flavor.  A brief description of
SIMSCRIPT is included, as is a sufficient description
of 20-GATE to render this material understandable
to the reader familiar with algebraic languages.
.A
Tonge, F. M.
Keller, P.
Newell, A.
.I 1254
.T
The Iteration Element
.W
A recent addition to the MAD language has made
the iteration structure of the MAD THROUGH statement
(corresponding to the ALGOL for statement and the FORTRAN
DO statement) available within expressions.
.A
Galler, B. A.
Fischer, M. J.
.I 1255
.T
A Method of Data List Processing With Application to EEG Analysis
.W
A set of subroutines is discussed, which is
designed to aid in the programming of computations
on indexed lists of numbers using machine language
or a symbolic assembly system.  The most commonly
performed list operations are outlined, and logically
arranged into five groups.  As an example, the
computation of power spectral density from the autocovariance
function is discussed for a class of EEG
signals.
.A
Philpott, C. M.
Lago, G. V.
.I 1256
.T
Dynamic Variable Formatting
.A
King, D. R.
.I 1257
.T
DEBUG-An Extension to Current On-Line Debugging Techniques
.W
A method of on-linr assembly-language debugging
which greatly simplifies several of the bookkeeping
tasks characteristically associated with that process
has been developed and implemented in a program
for the UNIVAC M-460 computer at Air Force Cambridge Research
Laboratories.  With this program, an online
user may insert or delete (in symbolic assembly language)
any number of lines at any point of his previously
assembled program in core, with the remainder
of the program being relocated appropriately.
.A
Evans, T. G.
Darley, D. L.
.I 1258
.T
An Extended Arithmetic Package
.W
In many fields, for example algebraic number
theory, arithmetic must be carried out to a degree
of precision which exceeds the normal hardware capacity
of most machines.  In such cases, an extended
arithmetic package provides a comprehensive and easy-to-use
way of performing such arithmetic.  Such
a package was coded for the IBM 7090.  In discussing
the general problems associated with the design
of an extended arithmetic package, specific reference is made to this program.
.A
Blum, B. I.
.I 1259
.T
Applications of Binary Numbers In Computer Routines
.W
A binary number can be thought of as an alternate
form of expression for either a set of letters
or a decimal number.  There are then three equivalent
expressions, easily translatable to one another,
each having different characteristics.  Four examples
are given in which the form of an expression is
changed to an equivalent expression to save space or gain power.
.A
Weldon, R. J.
Baker, R. L.
.I 1260
.T
Least-Squares Analysis of Resonance Spectra on Small Computers
.W
The problem of analyzing data from a Mossbauer
effect experiment is discussed.  By using the
cut step procedure for convergence and by imposing physical
constraints on the functional form of the
calculation it is possible to make the analysis on a
small computer.  The analysis has been carried out
on an IBM 1410 computer with a 40,000 BCD core memory.
.A
Marshall, S. W.
Nelson, J. A.
Wilenzick, R. M.
.I 1261
.T
Modeling and Simulation of Digital Networks
.W
The simulation of digital networks on a digital
computer provides the engineer with an effective
means of analyzing time-quantized logical behavior.  The
digital network is modeled as a set of time-dependent
or time-independent Boolean transformations; each transformation
describing the input-output relationship
of a model element comprising the network mode.  The
simplicity of utilizing the FORTRAN IV Programming
System as a digital Network Simulator is discussed an
illustrated.  This simplicity is derived from a
common modeling technique applicable to combinational
and sequential digital networks and a systematic
programming approach.
.A
Larsen, R. P.
Mano, M. M.
.I 1262
.T
Procedure-Oriented Language Statements to Facilitate Parallel Processing
.W
Two statements are suggested which allow a programmer
writing in a procedure-oriented language
to indicate sections of program which are to be executed
in parallel.  The statements are DO TOGETHER
and HOLD.  These serve partly as brackets in establishing
a range of parallel operation and partly to
define each parallel path within this range.  DO TOGETHERs
may be nested.  The statements should be particularly
effective for use with computing devices capable of
attaining some degree of compute-compute overlap.
.A
Opler, A.
.I 1263
.T
Metalanguage and Syntax Specification
.W
Two metalanguages are described, one sufficient
for the table specification of the ALGOL syntax,
the other with additional metaoperators adequate and used
for the formal table description of Basic FORTRAN.
.A
Burkhardt, W. H.
.I 1264
.T
BLNSYS-A 1401 Operating System with Braille Capabilities
.W
BLNSYS is an operating system designed for
a 4K 1401 with common optional features and two
attached tape drives.  Printed output of this system
or of executing programs may be in either English
or braille.  Even though this system was written for
a small machine with minimal peripheral equipment,
jobs may be batched, so that card handling and lost
processing time is at a minimum.  This system will
perform any or all of the following users specified
functions: assemble SPS source decks, post list,
produce condensed or uncondensed object decks, execute
user's program, list card input to a program,
list punched output, provide a storage dump, execute
a program submitted for execution as an uncondensed
object deck under debugging trace control, card-to-braille
conversion, brailled listings of 7040 IBSYS
batch output, and update or duplicate the system tape
itself.  Input-ouput subroutines are also included
in the system.
.A
Landwehr, J. B.
McLaughlin, C.
Mueller, H.
Lichstein, M.
Pollack, S. V.
.I 1265
.T
On the Relative Efficiencies of Context-Free Grammar Recognizers
.W
A number of diverse recognition procedures
that have been proposed for parsing sentences with
respect to a context-free grammar are described in this
paper by means of a common device.  Each procedure
is defined by giving an algorithm for obtaining a nondeterministic
Turing Machine recognizer that is
equivalent to a given context-free grammar.  The formalization
of the Turing Machine has been chosen
to make possible particularly simple description of
the parsing procedures considered.  An attempt has
been made to compare recognition efficiencies for the
procedures defined.  For a few simple grammars
and sentences a formal comparison has been made.  Empirical
comparison of the recognition of more realistic
programming languages such as LISP and ALGOL has been
made by means of a program which simulates the
Turing Machine on the Univac M-460 computer.  Several
algorithms for producing grammars equivalent to
a given context-free grammar have been considered, and
the increase in recognition efficiency they afford
has been empirically investigated.
.A
Griffiths, T. V.
Petrick, S. R.
.I 1266
.T
Considerations Relating to Purpose of FORTRAN Standardization
(Appendixes to ASA FORTRAN Standard)
.I 1267
.T
Performance of Systems Used for Data Transmission
Transfer Rate of Information Bits -An ASA Tutorial
Standard
.W
Information thruput as a characteristic of
systems performance is discussed.  This discussion
includes the pertinent aspects of information transfer,
of determination of transfer rate of information
bits (TRIB), of residual errors, and of standard measurement
conditions.  The paper also presents an
orderly arrangement of characteristics and parameters
that affect information thruput, and some examples
on procedures for determining a thruput rate in terms of
TRIB.  It concludes that a performance characteristic
involving information rate can best be expressed as the
TRIB in conjunction with the Residual Error Rate.
.I 1268
.T
Logarithm of a Complex Number (Algorithm 243 [B3])
.A
Boothroyd, J.
.I 1269
.T
Computation of Fourier Coefficients (Algorithm [C6])
.A
Teijelo, L.
.I 1270
.T
On ALGOL Education: Automatic Grading Programs
.W
Two ALGOL grader programs are presented for
the computer evaluation of student ALGOL programs.
One is for a beginner's program; it furnishes random data
and checks answers. The other provides a searching
test of the reliability and efficiency of an integration
procedure.  There is a statement of the essential
properties of a computer system, in order that
grader programs can be effectively used.
.A
Forsythe, G. E.
Wirth, N.
.I 1271
.T
Secondary Key Retrieval Using an IBM 7090-1301 System
.W
The secondary key retrieval method involves
the preparation of secondary storage lists from
primary data records. Search requests are satisfied by
logical operations on appropriate lists, producing
a complete set of addresses of primary records relevant
to the request.  Experimental results are presented
and a comparative analysis is given.
.A
Davis, D. R.
Lin, A. D.
.I 1272
.T
Expanding the Editing Function In Language Data Processing
.W
In automatic abstracting, citation indexing,
mechanical translation and other such procedures,
editing is required whenever the automatic method leaves
something to be desired.  This paper discusses
the economy of editing as a function of the amount of condensation
of text in language processing operations,
and then contends that editing can be regarded as an
opportunity rather than as an unwelcome necessity.
 "Heavy editing," which goes beyond mere correction
and improvement of computer output, is exemplified
by the use of a concordance in preparing a survey article
or lecture.  Other opportunities for heavy
editing are described, chief among them being interpretation and
expansion of computer output in such
processes as factor analysis.  Applications are described,
such processes as factor analysis.  Applications
are described, such as the quick, unbiased evaluation
of a large volume of incoming mail or telegrams,
yielding summary reports not possible for either
humans or computers to produce alone.
.A
Doule, L. B.
.I 1273
.T
Remark on Romberg Quadrature
.W
A modified form of Romberg quadrature is described,
which is less sensitive to the accumulation
of rounding errors than the customary one.
.A
Krasun, A. M.
Prager, W.
.I 1274
.T
On the Numerical Solution of an N-Point Boundary
Value Problem for Linear Ordinary Differential
Equations
.W
A method for the numerical solution of then-point
boundary value problem for homogeneous linear
ordinary differential equations is developed.  The
method requires two Runge-Kutta integrations over
the interval under consideration and the solution of
a linear system of equations with n-1 unknowns.
.A
Day, J. T.
.I 1275
.T
Code Structures for Protection and Manipulation
of Variable Length Items (Corrigendum)
.A
Ramamoorthy, C. V.
.I 1276
.T
Still Another Use for FORTRAN II Chaining
.I 1277
.T
The Use of Cobol Subroutines in Fortran Main Programs
.A
Tajiri, K.
.I 1278
.T
Wengert's Numerical Method for Partial Derivatives,
Orbit Determination and Quasilinearization
.W
In a recent article in the Communications
of the ACM, R. Wengert suggested a technique for
machine evaluation of the partial derivatives of a function
given in analytical form.  In solving non-linear
boundary-value problems using quasilinearization many
partial derivatives must be formed analytically
and then evaluated numerically.  Wengert's method appears
very attractive from the programming viewpoint
equations which might not otherwise be undertaken.
.A
Bellman, R. E.
Kagiwada, H.
Kalaba, R. E.
.I 1279
.T
Use of a Conditional Base Number System for
Encoding Sequences of Correlated Characters
.W
A procedure is described for the relatively
efficient encoding of sequences of characters which
have predecessor-successor selection rules.  The procedure
is shown to assign a unique integer to each
sequence and to generate a reasonably compact set of values.
.A
Brown, R. M.
.I 1280
.T
Numerical Integration of a Differential-Difference
Equation with a Decreasing Time-Lag
.W
Systems in which variable time-lags are present
are of common occurrence in biology.  Variable
flow rates are a common cause of these variable lags.
 At present no extensive body of knowledge exists
concerning the effects which these variable lags can
cause.  Shown here is a method of reducing some
differential-difference equations to ordinary differential
equations which can then be studied numerically
with ease.  Subsequent study will deal with situations
in which multiple-lags and lags dependent on the
solution itself are present.
.A
Bellman, R. E.
Buell, J. D.
Kalaba, R. E.
.I 1281
.T
Data Input by Question and Answer
.W
A data input scheme for a time-sharing computer
is described in this paper.  Instead of using
format statements to determine the input, the computer
asks the user for the required values one at a
time.  The computer converses with the user during the
input process, checks for errors, provides standard
data, and allows editing of values input.
.A
Pyle, I. C.
.I 1282
.T
The Use of FORTRAN in Subroutines with COBOL Main Programs
.W
By using the proper COBOL coding techniques and
accounting for differences in storage allocation
and library routines between the two languages, it is
possible to write FORTRAN IV subroutines that may
be called from COBOL main programs.  Such a technique
enables the programmer to take advantage of the
most useful properties of each language while
minimizing their respective disadvantages.
.A
Shavell, Z. A.
.I 1283
.T
Matrix Inversion (Algorithm 231 [F1])
.A
Ferring, M.
.I 1284
.T
Bessel Function for a Set of Integer Orders
.A
Stafford, J.
.I 1285
.T
Eigenvalues and Eigenvectors of a Real Symmetric
Matrix by the QR Method (Algorithm 254 [F2])
.A
Businger, P. A.
.I 1286
.T
Eigenvalues of a Real Symmetric Matrix
by the QR Method (Algorithm 253 [F2])
.A
Businger, P. A.
.I 1287
.T
Vector Coupling or Clebsch-Gordan Coefficients (Algorithm 252 [Z])
.A
Gunn, J. H.
.I 1288
.T
CLP-The Cornell List Processor
.W
Presented in this paper are the highlights of
CLP, a teaching language which has been employed
at Cornell University and was constructed to serve as a means
of introducing simulation and other list-processing
concepts.  The various advantages of CLP are discussed and examples are given.
.A
Conway, R. W.
Delfausse, J. J.
Maxwell, W. L.
Walker, W. E.
.I 1289
.T
Proposed Revised American Standard Code for Information Interchange
.I 1290
.T
Transparent-Mode Control Procedures for Data
Communication, Using the American Standard Code
for Information Interchange -A Tutorial
.W
This paper gives the considerations of Task
Group X3.3.4 in the area of transparent-mode data
communication control philosophy.  The appearance of this
paper was forecast (underthe name of "second-level
control") in the earlier tutorial paper, "Control Procedures
for Data Communications," Task Group document
X3.3.4.44, dated May 1964.  The present paper elaborates
upon solutions to the problems of transparency
to the basic ASCII communication control characters
as outlined in the previous paper mentioned above.
 Moreover, it goes on to cover the additional control problems
of handling material such as off line encrypted
data or non-ASCII codes by means of systems providing
complete character transparency.  It does not cover
concepts of transparency in which the normal character
structure or modulation rate of a system may be
abandoned.  In conjunction with the earlier tutorial
paper, this paper is expected to lead to a proposal
for stand ardizationof data communication control procedures
using the American Stand ard Code for Information
Interchange.
.I 1291
.T
Tabular Input of Data
.A
George, R.
.I 1292
.T
On a Divide-and-Correct Method For Variable Precision Division
.W
Described in this paper is a divide-and-correct
method for variable precision division in digital
computers.  Unlike the earlier methods of Stein and
Pope, the present method uses a suitably rounded
form of the normalized divisor for getting an estimate
of the quotient characters.  This results in a
correction of at most plus or minus one to the estimate,
to obtain the exact quotient character.  It
is believed that this method will be widely applicable
for division operations in variable word-length
character-oriented machines.
.A
Krishnamurthy, E. V.
.I 1293
.T
Method is Randomness
.W
Certain nonrandom properties of a commonly used
random number generator are described and analyzed.
.A
Greenberger, M.
.I 1294
.T
Note on Triple-Precision Floating-Point Arithmetic with 132-Bit Numbers
.W
In a recent paper, Gregory and Raney described
a technique for double-precision floating-point
arithmetic.  A similar technique can be developed for
triple-precision floating-point arithmetic and
it is  the purpose of this note to describe this technique.
 Only the multiplication and the division
algorithms are described, since the addition-subtraction
algorithm can be obtained by a trivial modification
of the algorithm in Gregory's and Raney's paper.
.A
Ikebe, Y.
.I 1295
.T
PERT Time Calculations Without Topological Ordering
.W
A simplified technique is presented for PERT
Time calculations without topological ordering.
 Each event is assigned a unique memory location.  An activity
is represented by a link.  A link is defined
as a memory location containing the address of another
memory location.  The time information for an
activity is carried with its link.  For a typical net,
the majority of activities can be described by
one 36-bit cell each.  The remainder use two 36-bit
cells each.  The links are unidirectional; forward
during the T(E) calculation (expected completion time for
an activity);backward during the T(L) calculation
(time latest allowable for completion of an activity).
The calculations progress through the net topologically
even though the net is not represented topologically in core.
.A
Lass, S. E.
.I 1296
.T
Ative (Algorithm 205 [E4])
.A
Wasscher, E. J.
.I 1297
.T
Steep1 (Algorithm 203 [E4])
.A
Varah, J. M.
.I 1298
.T
Adaptive Numerical Integration by Simpson's Rule (Algorithm 145 [D1])
.A
Pike, M. C.
.I 1299
.T
Solutions of the Diophantine Equation (Algorithm 139 [A1])
.A
Bowlden, H. J.
.I 1300
.T
Function Minimization (Algorithm 251[E4])
.A
Wells, M.
.I 1301
.T
On ALGOL I/O Conventions
.A
Zaremba, W. A.
.I 1302
.T
Parallel Signaling Speeds for Data Transmission
(Proposed American Stand ard)
.I 1303
.T
A Correspondence Between ALGOL 60 and Church's Lambda-Notation: Part II*
.A
Landin, P. J.
.I 1304
.T
A Rapid Turnaround Multi-Programming System
.W
In this paper, basic features, system characteristics
and the control algorithm for a multi-programming
system with rapid turnaround time are described.
.A
Irons, E. T.
.I 1305
.T
The Internal Structure of the FORTRAN CEP Translator
.W
The FORTRAN CEP translator converts a source
program written in the FORTRAN CEP language into
an object program written in the language of the CEP
computer.  In this paper, after an outline of the
CEP computer, the internal structure of the translator
is described.  Emphasis is on the compilation
of expressions, of input/output lists, and of subscripted variables.
.A
Mancino, O. G.
Cecchi, M. M.
.I 1306
.T
A Class of Unambiguous Computer Languages
.W
Discussed in this paper is the concept of
a fully nested computer language which may be one
means of designing computer languages which would be completely
free of ambiguities.  Several suggestions
are also given here for the redefinition of ALGOL as a fully nested language.
.A
Johnston, J. B.
.I 1307
.T
A Lightpen-Controlled Program For On-Line Data Analysis
.W
This paper describes a technique designed
to ease the use of a data processing system by a
person, in particular, a scientist, who is intimately and
primarily concerned with interpreting the significance
of data handled by the system.  Since such a person is
often unable to spend the time necessary to master
a programming language, it is essential that he be aided
in composing commands to the computer.  In the
system described, the user is not required to learn
or remember the vocabulary of the language because
the vocabulary is displayed before him on"menus" by
means of a computer-drive scope.  He selects the
various vocabulary elements required by pointing with
the light pen.  By use of a small unordered set
of rewriting rules applied as a result of light pen
selections, the user generates only syntactically
correct commands to the system.  He does not have to learn
or remember the grammar.  The program restricts
the user severely in the particular language he can use,
but the method for communicating with the program
makes these restrictions seem quite natural and unconstraining.
 The program has been used successfully
for over ten months.
.A
Goodenough, J. B.
.I 1308
.T
A Mathematical Model for Mechanical part Description
.W
The flexibility of a mathematical model takes
advantage of the common information requirements
of computer-aided engineering drawing, numerical control
tape generation, and physical characteristic
computation.  By judicious control of man-machine communication
requirements, improved results over conventional
engineering design processes are possible.  An English-like
input language, tailored for use by draftsmen
and designers, will describe the part and specify the
output desired.  One approach to the mathematical
model consists of a group of surface-defining quadric
equations, which are created by a system of modular
subprogram.  Other subprograms will convert the mathematical
model into instructions for driving automatic
drafting machines and numerical controlled machine tools.
 Physical part characteristics, such as center
of gravity, can be computed by subprograms and used in
dynamic analysis work.  The proposed overall system
is presented and experiments and demonstrations are discussed.
.A
Luh, J. Y. S.
Krolak, R. J.
.I 1309
.T
A Computer User-Oriented System
.W
A computer language system has been developed
which makes possible fast preparation of management
reports, regardless of computational complexity or format
variety.  Costs are sufficiently low so that
individually tailored reports can be prepared for every
manager.  The system requires initial preparation
of large data banks containing data in elementary form.
 Use of two special languages, EXTRACT and MATRAN,
permits selective extraction of any data subset, efficient
processing through any computational sequence,
and flexible presentation of results in either tabular
or graphical form.  Matrix algebra is used as
a fundamental vehicle for accomplishing both manipulation and computation.
.A
Montillon, G. D.
.I 1310
.T
A Rapid Braille Transliteration Technique for Certain IBM Machines
.A
Weiler, W. J.
Klema, V. C.
.I 1311
.T
Efficient Autocorrelation
.A
Schmid, L. P.
.I 1312
.T
Recursion and Iteration
.A
Rice, H. G.
.I 1313
.T
Construction of Nonlinear Programming Test Problems
.A
Rosen, J. B.
Suzuki, S.
.I 1314
.T
The Organization of Symbol Tables
.W
An efficient symbol table organization is an
important feature in the design of any compiler.
 During the construction of the Virginia ALGOL 60 compiler
for the Burroughs B205, the primary consideration
in the symbol table design was that the recognition of
identifiers and reserved words should be as rapid
as possible.  The general features of the technique are described.
.A
Batson, A.
.I 1315
.T
Automation of the Radioisotope Accountability System
.W
The Radioisotope Service of the Veterans Administration
Hospital, Omaha, Nebraska, used a manual
system of radioisotope accountability for three years.  The
procedure which was satisfactory but time-consuming
was converted from manual to a fully automated computer
system in January, 1963.  The program for purchased
radioisotopes is written in FORMAT FORTRAN for the IBM
1620 Computer.  A second program for maintaining
accountability for reactor-created radioisotopes is written
 in the FORCOM programming language.  A minimum
amount of bookkeeping is required by the reactor operating
staff.  The United States Atomic Energy Commission
regulations specify that records be kept.  This system
provides detailed records for each container of
radioactive material purchased and/or created in the Triga
reactor indicating the amounts received, used,
and/or transferred to the health physicist for disposal.
 Consolidated records contain total amounts
received, used, and/or disposed of for any specified period
of time.  Purchased radioisotopes are reported
in millicuries; reactor-created radioisotopes in microcuries.
.A
Lahners, E. L.
.I 1316
.T
Bessel Functions of the First Kind (Algorithm 236 [S17])
.A
Gautschi, W.
.I 1317
.T
Poisson-Charlier Polynomials (Algorithm 234 [S23])
.A
Samet, P.A.
.I 1318
.T
Arccossin (Algorithm 206 [B1])
.A
Bowlden, H. J.
.I 1319
.T
Crout with Equilibration and Iteration (Algorithm 135 [F4])
.A
Meissner, L. P.
.I 1320
.T
Inverse Permutation (Algorithm 250 [G6])
.A
Boonstra, B. H.
.I 1321
.T
Outreal N (Algorithm [I5])
.A
Wirth, N. E.
.I 1322
.T
Netflow (Algorithm 248 [H])
.A
Briggs, W. A.
.I 1323
.T
A Correspondence Between ALGOL 60 and Church's Lambda-Notation: Part I*
.W
This paper describes how some of the semantics
of ALGOL 60 can be formalized by establishing
a correspondence between expressions of ALGOL 60 and expressions
in a modified form of Church's L-notation.
 First a model for computer languages and compute behavior
is described, based on the notions of functional
application and functional abstraction, but also having
analogues for imperative language features.
Then this model is used as an "abstract object language"
into which ALGOL 60 is mapped.  Many of ALGOL
60's features emerge as particular arrangements of
a small number of structural rules, suggesting new
classifications and generalizations.  The correspondence
is first described informally, mainly by illustrations.
 The second part of the paper gives a formal description,
i.e. an "abstract compiler" into the "abstract
objct language."  This is itself presented in a "purely
functional" notation, that is one using only
application and abstraction.
.A
Landin, P. J.
.I 1324
.T
Answering English questions by Computer: A Survey
.W
Fifteen experimental English language question-answering
systems which are programmed and operating
are described and reviewed.  The systems range from a conversation
machine to programs which make sentences
about pictures and systems which translate from English
into logical calculi.  Systems are classified
as list-structured data-based, graphic data-based, text-based
and inferential.  Principles and methods
of operations are detailed and discussed.  It is concluded
that the data-base question-answer has passed
from initial research into the early developmental
phase.  The most difficult and important research
questions for the advancement of general-purpose language
processors are seen to be concerned with measuring,
dealing with ambiguities, translating into formal
languages and searching large tree structures.
.A
Simmons, R. F.
.I 1325
.T
Remote, On-Line, Real-time Computer Diagnosis
of the Clinical Electrocardiogram
.W
Presented in this paper is a brief report on
the hardware, software, system configuration and
function of a system for the remote, online, real-time digital
computer diagnosis of clinical electrocardiograms.
 It seems likely that efforts of this sort will lead
to a satisfactory solution to the problem of the
automatic diagnosis of electrocardiograms.  Current
attempts by the authors to extend the diagnostic
capabilities of the present system are particularly concerned
with increasing the fidelity of the adaptive
matched filters, the development of three dimensional pattern analysis,
the analysis of parallel electrocardiographer-computer
diagnostic interaction, and a study of the possibility
of introducing major, tree-like branching decisions
early in the diagnostic process.
.A
Whipple, G. H.
Dickson, J. F.
Horibe, H.
Stark, L.
.I 1326
.T
Boundary Networks
.W
A feasible computer procedure is described
for determining the total or partial inclusion of
arbitrarily given points and lines with respect to a
set of general polygonal domains which partition
a plane bounded region.  A scheme for the computer representation
of the boundaries of the domains and
an algorithm, based on this  scheme, for evaluating
the inclusion relations are specified in detail.
 The method employs several levels of selection criteria
for the purpose of reducing the number of accesses
to auxiliary storage devices and the amount of boundary
data for which processing is required.
.A
Loomis, R. G.
.I 1327
.T
Use of Decision Tables in Computer Programming
.W
A decision table is a tabular form for displaying
decision logic.  Decision tables have many
inherent advantages.  The technique to be illustrated
puts these advantages to use in that it enables
one to program directly from a decision table.  The technique
is based on the creation of a binary image
of a limited entry decision table in computer memory.
 A binary image of a given set of input conditions
can also be created.  This data image is used to scan
the decision table image to arrive at the proper
course of action.  There are several advantages gained
from the programming point view: (1) amount of
computer memory used is drastically reduced, (2) programming
is simplified, and (3) documentation is
brief and clear.
.A
Kirk, H. W.
.I 1328
.T
Further Remarks on Reducing Truncation Errors
.A
Kahan, W.
.I 1329
.T
Simulation of Boolean Functions in a Decimal computer
.A
Mano, M. M.
.I 1330
.T
Automated Plotting Flow-Charts on a Small Computer
.A
Anderson, H. E.
.I 1331
.T
Code Structures for Protection and Manipulation of Variable-Length Items
.W
When items are made up of a variable number
of characters, each containing the same number
of bits, certain control information (partition symbols)
is inserted to mark their separations.  Since
errors in identification of these control characters
can lead to serious trouble, methods of protecting
these symbols are indicated.  A 6-bit code assignment
of alphanumeric characters for fixed word-length
computers is given and its suitability for error detection
and variable-length item manipulation is shown.
 Also indicated is its flexibility during certain arithmetic operations.
.A
Ramamoorthy, C. V.
.I 1332
.T
Subroutine Assembly
.W
A description is given of an assembly system,
which requires only one pass and does not maintain
a table of information about the subroutine library.
.A
Samet, P. A.
.I 1333
.T
Reducing Truncation Errors Using Cascading Accumulators
.W
When accumulating a large number of quantities
as in numerical integration, the sum itself
may become much larger than the individual addends.
 This results in truncation error.  Much of this
error can be eliminated using cascading accumulators
as noted in a recent article by Wolfe.  A simpler
and slightly more flexible algorithm is presented which
deals also with the case of negative addends.
.A
Ross, D. R.
.I 1334
.T
Mechanization of Tedious Algebra: The
Newcomb Operators of Planetary Theory
.W
A computer program has been written to generate
tables of formulas for the Newcomb operators
of planetary theory.  The Newcomb operators are expressed
as polynomials in two variables, one of which
stands for a simple differential operator, and the other
for an arbitrary integer.  The polynomials are
generated by a recurrence scheme.  The program is coded in
FORTRAN, using simple array manipulation techniques
to perform the algebraic operations.  Formulas for over
100 Newcomb operators have been produced by the
program and typeset photographically on an S-560 Photon system.
.A
Gerard, J. M.
Izsak, I. G.
Barnett, M. P.
.I 1335
.T
Character Set for Optical Character
Recognition (Proposed American Stand ard)
.I 1336
.T
NPL: Highlights of A New Programming Language
.A
Radin, G.
Rogoway, H. P.
.I 1337
.T
EULER: A Generalization of ALGOL, and its Formal Definition
.A
Wirth, N.
Weber, H.
.I 1338
.T
Additional Comments on a Problem in Concurrent Progamming Control
.A
Knuth, D. E.
.I 1339
.T
A Contribution to the Development of ALGOL
.A
Wirth, N.
Hoare, C. A. R.
.I 1340
.T
Multiplexing of Slow Peripherals
.W
The philosophy of a monitor which allows slow
output devices to be multiplexed is presented.
.A
Abraham, C.
Lance, G. N.
Pearcey, T.
.I 1341
.T
Levels of Computer Systems
.W
In building current computer systems, we tend
to break them down into "levels" of control,
command and communication; in using the system, we break
our problems down correspondingly.  The continued
use of such a structure raises questions about its effects
on the usefulness of future systems, particularly
with regard to such trends as time sharing, parallel
programming, and, eventually, systems which learn.
 In this essay some of these questions are posed, and
the general attitude we must take in pursuing the
problem further is discussed.
.A
Bryant, P.
.I 1342
.T
Transportation Problem (Algorithms 293 [H])
.A
Bayer, G.
.I 1343
.T
Havie Integrator (Algorithm 257 [D1])
.A
Farkas, I.
.I 1344
.T
Statistical Computations Based Upon Algebraically Specified Models
.W
Based upon a machine-readable statistical model
and related symbolic specifications, an efficient
method of performing calculations for statistical models
of a balanced complete nature is presented.
 Fixes, mixed, and random analysis of variance models
are considered.  A procedure for obtaining variance
components and calculated F statistics for the model terms is included.
.A
Schlater, J. E.
Hemerle, W. J.
.I 1345
.T
Tensor Calculations on the Computer
.W
A FORMAC program has been written which is capable
of calculating various quantities of interest
in tensor calculus.  Using this code, Christoffel symbols
have been calculated for 12 basic orthogonal
coordinate systems.
.A
Waltons, J. J.
.I 1346
.T
On the Application of the Process of Equalization
of Maxima to Obtain Rational Approximation
to Certain Modified Bessel Functions
.W
The second Remes algorithm as originally established
for polynomials, may converge or not when
the approximating functions are rational.  However, the
few results known in this domain show how efficient
the algorithm can be to obtain approximations with a
small error, much more than in the polynomial case,
in which the best approximation can be very nearly
approached directly by a series development.  The
aim of this paper is to investigate the limitations
of the applicability of certain extensions of the
algorithm to the case where the approximations are rational
as well as to present some numerical results.
.A
Gargantini, L.
.I 1347
.T
General Time-Varying Systems Error Sensitivities Program
.W
The evaluation, by the propagation of variance
technique, of the sensitivity of time-varying
systems to initial condition and parameter errors, involves
the determination of several system-dependent
partial derivative matrices.  This requirement has led to
separate programs for each system under investigation.
 A new program, through utilization of the Wengert differentiation
technique, automatically determines
the required matrices from specific system equations supplied
in subroutine form at execution time, eliminating
the need for individualized programs, and presaging the
further development of extremely general computer
programs.
.A
Wilkins, R. D.
.I 1348
.T
FLOWTRACE, A Computer Program for Flowcharting Programs
.W
The FLOWTRACE system produces flowcharts of programs
written in "almost any" programming language.
 One most describe the syntax of the control statements
in his language; for this purpose a metalanguage
is available.  The resultant object deck is used to
flowchart any programs in the language described.
 Several examples of FAP and SNOBOL flowcharts are given.
 However, it is not necessary to confine one's
scope to existing languages.  One may define his own
language in any "well-structured" manner.  This
feature is particularly useful when it is desirable
to chart only comments within a program.  Such an
approach permits the documentation of descriptive remarks
and avoids the inclusion of coding details.
.A
Sherman, P. M.
.I 1349
.T
Computing Capabilities at Western European Universities
.W
This report on the author's trip to universities
in Western Europe in the summer of 1966 gives
brief descriptions of computing activities at each institution
visited.  Present equipment capabilities
vary from moderate to large scale; however, many institutions
plan to acquire complex time-shared systems
in the near future.  In the author's opinion, the state
of the art lags behind that on this continent.
 This lag is attributed to four principal factors: (a)
the handicapping organization of academic procedures;
(b) the university-government financial relationship;
(c) the subordinated organization of the computing
facility; (d) the paucity of professional interchange
of knowledge.  The effects of these constraints
are explicated.
.A
Finerman, A.
.I 1350
.T
The Augmented Predictive Analyzer for Context-Free
Languages-Its Relative Efficiency
.W
It has been proven by Greibach that for a given
context-free grammar G, a standard-form grammar
Gs can be constructed, which generates the same languages
as is generated by G and whose rules are all
of the form Z --> cY(1) ... Y(m), (m >= O) where Z and
Y(i) are intermediate symbols and c a terminal
symbol.  Since the predictive analyzer at Harvard uses
a standard-form grammar, it can accept the language
of any context-free Grammar G, given an equivalent standard-form
grammar Gs.  The structural descriptions
SD(Gs,X) assigned to a given sentence X by the predictive
analyzer, however, are usually different from
the structural descriptions SD(G,X) assigned to the
same sentence by the original context-free grammar
G from which Gs is derived.  In Section 1, an algorithm,
originally due to Abbott is described standard-form
grammar each of whose rules is in standard form, supplemented
by additional information describing its
derivation from the original context-free grammar.
A technique for performing the SD(Gs,X) to SD(G,X)
transformation effectively is also described.  In section
2, the augmented predictive analyzer as a parsing
algorithm for arbitrary context-free languages is compared
with two other parsing algorithms: a selective
top-to-bottom algorithm similar to Irons' "error correcting
parse algorithm" and an immediate constituent
analyzer which is an extension of Sakai-Cocke's algorithm
for normal grammars.  The comparison is based
upon several criteria of efficiency, covering core-storage
requirements, complexities of the programs
and processing time.
.A
Kuno,S.
.I 1351
.T
Automatic Error Bounds on Real Zeros of Rational Functions
.W
A procedure for implementing an interval arithmetic
version of the Newton-Raphson method is
proposed.  The procedure require only a starting interval
over which the zeros of a given rational function
are to be located.  The method automatically provides bounds
for roundoff error.
.A
Dargel, R. H.
Loscalzo, F. R.
Witt, T. H.
.I 1352
.T
Automatic Integration of a Function with a Parameter
.W
Two efficient methods for automatic numerical
integration are Romberg integration and adaptive
Simpson integration.  For integrands of the form f(x)g(x,a)
where a is a parameter, it is shown that
Romberg's method is more efficient.  A FORTRAN program
shows how to achieve this greater efficiency.
.A
Rabinowitz, P.
.I 1353
.T
Techniques for Automatic Tolerance Control in Linear Programming
.W
In this technical note, the numerical steps
for the simplex method of linear programming are
reviewed and the tolerances needed in the numerical procedure
are defined.  Objective criteria are given
for accomplishing the numerical steps of the method
and the calculation of necessary tolerances.
.A
Clasen, R. J.
.I 1354
.T
Conversion of Decision Tables to Computer
Programs by Rule Mark Techniques
.W
The rule mask technique is one method of converting
limited entry decision tables to computer
programs.  Recent discussion suggest that in many circumstances
it is to be preferred to the technique
of constructing networks or trees.  A drawback of the
technique as hitherto presented is its liability
to produce object programs of longer run time than necessary.
 In this paper a modification of the technique
is discussed which takes into account both rule frequencies
and the relative times for evaluating conditions.
 This can materially improve object program run time.
.A
King, P. J. H.
.I 1355
.T
Regular Coulomb Wave Functions (Algorithm 292 )
.A
Gautschi, W.
.I 1356
.T
Havie Integrator (Algorithm 257 [D1])
.A
Hillstrom, K.
.I 1357
.T
Examination Scheduling (Algorithm 286 [H])
.A
Williams, R.
.I 1358
.T
Syntax Macros and Extended Translation
.W
A translation approach is described which allows
one to extended the syntax and semantics of
a given high-level base language by the use of a new
formalism called a syntax-macro.  Syntax-macros
define string transformations based on syntactic elements
of the base language.  Two types of macros
are discussed, and examples are given of their use.  The
conditional generation of macros based on options
and alternatives recognized by the scan are also described.
.A
Leavenworth, B. M.
.I 1359
.T
Data Filtering Applied to Information Storage and Retrieval Applications
.W
Manipulation of data strings is the most complex
processing function in information storage
and retrieval applications.  Data string manipulation
is discussed within the context of an interpretive
processing environment controlled by the use of procedural
directives.  The sequence of procedural directives
is derived from a job assumed to be expressed in a user-oriented
source language.  Each data string with
the structured data environment (data bank) is explicitly
or implicitly related to a format declaration
residing in a format library.  The processing mechanics
associated with data string manipulation is developed
in accordance with a generalized data filtering concept.
 This results in the implementation of a two-part
data filter module that satisfies internal processing
functions by filtering data strings through format
declarations associated with its input and output ports.
.A
Larsen, R. P.
.I 1360
.T
Description of Systems Used for Data Transmission* (An ASA Tutorial)
.I 1361
.T
Rectangular Holes in Twelve-Row Punched
Cards* (Proposed American Standard)
.I 1362
.T
Code Extension in ASCII* (An ASA Tutorial)
.W
The American Standard Code for Information
Interchange (ASCII) contains a number of control
characters associated with the principle of code extension,
that is, with the representation of information
which cannot be directly represented by means of the characters
in the Code.  The manner of use of these
characters has not previously been completely described.
 This paper presents a set of mutually consistent
philosophies regarding code extension applications,
and suggests a corollary set of doctrines for the
application of the code extension characters.  Distinctions
are drawn between code extension and such
other concepts as "graphic substitution" or "syntactic
representation" which are often used to meet similar
requirements.  Also covered are certain topics which
are not truly concerned with code extension but
which are often linked with it in discussion on code applications.
 The material in this paper is equally
applicable in principle to the (proposed) ISO international
7-bit code for information interchange.
.I 1363
.T
A General Method of Systematic Interval Computation
for Numerical Integration of Initial Value
Problems
.W
A procedure is given for continuously computing
and monitoring the step size to be used by
a self-starting, p-th order numerical integration method
to solve an initial value problem.  The procedure
uses an estimate of the truncation error to calculate the step size.
.A
Martin, W. C.
Paulson, K. C.
Sashkin, L.
.I 1364
.T
Mathematical Experimentation in Time-Lag Modulation
.W
Equations of the form du/dt = g(u(t),u(h(t)))
arise in a number of scientific contexts.  The
authors point out some interesting properties of the
solution u'(t) = -u(t-1-k*sin(wt))+sin(at).  These
properties were obtained by means of numerical solution.
.A
Bellman, R.
Buell, J.
Kalaba, R.
.I 1365
.T
Eliminating Monotonous Mathematics with FORMAC
.W
The FORMAC (FORmula MAnipulation Compiler)
programming system provides a powerful tool for
performing mathematical analysis.  It is an extension
of FORTRAN IV which permits the use of the computer
to perform the tedious algebraic computations that arise
in many different fields.  Among the areas in
which it has been successfully used are: differentiation
of complicated expressions, expansion of truncated
power series, solution of simultaneous equations with
literal coefficients, nonlinear maximum likelihood
estimation, tensor analysis, and generation of the coefficients
of equations in Keplerian motion.  These
types of analysis-which arose in the solution of specific
practical problems in physics, engineering,
astronomy, statistics and astronautics-are discussed in
the paper.  In addition to its usage for specific
problem solutions, FORMAC can also be used to automate
the analysis phase in certain production programming.
 Several such applications are presented.
.A
Tobey, R. G.
.I 1366
.T
Computer Simulation-Discussion of the
Technique and Comparison of Languages
.W
The purpose of this paper is to present a comparison
of some computer simulation languages
and of some of the involved in comparing software packages
for digital computers are discussed in Part
I.  The issue is obvious: users of digital computers
must choose from available languages or write their
own.  Substantial costs can occur, particularly in training,
implementation and computer time if an inappropriate
language is chosen.More and more computer simulation
languages are being developed: comparisons and
evaluations of existing languages are useful for designers
and implementers as well as users.  The second
part is devoted to computer simulation and simulation
languages.  The computational characteristics of
simulation are discussed with  special attention being
paid to a distinction between continuous and discrete
change models.  Part III presents a detailed comparison
of six simulation languages and packages: SIMSCRIPT,
CLP, CSL, GASP, CPSS and SOL.  The characteristics of
each are summarized in a series of tables.  The
implications of this analysis for designers of languages,
for users, and for implementers are developed.
 The conclusion of the paper is that the packages now
available for computer simulation offer features
which none of the more general-purpose packages do and
that analysis of strengths and weaknesses of each
suggests ways in which both current and future simulation
languages and packages can be improved.
.A
Teichroew, D.
Lubin, J. F.
.I 1367
.T
Character Structure and Character Parity Sense
for Parallel-by-Bit Data Communication in ASCII*
(Proposed American Standard)
.I 1368
.T
Systematic Generation of Hamiltonian Circuits
.W
For a combinatorial matrix which may specify
both directed and nondirected arcs, the paper
describes a computer program which generates systematically
and exhaustively all the Hamiltonian circuits.
Specific application is made to the "traveling salesman" problem.
.A
Roberts, S. M.
.I 1369
.T
Half Rotations in N-Dimensional Euclidean Space
.W
An iterative procedure is described for determining
half rotations in n-dimensional Euclidean
space. The method is a variant of the cyclic Jacobi
procedure and utilizers elementary plane rotations
to obtain the half rotation matrix.  Numerical examples are given.
.A
McCamon, R. B.
.I 1370
.T
Linear Equations, Exact Solutions (Algorithm 290 [F4])
.A
Boothroyd, J.
.I 1371
.T
Logarithm of Gamma Function (Algorithm 291 [S14])
.A
Pike, M. C.
Hill, I. D.
.I 1372
.T
Direct Search (Algorithm 178 [E4])
.A
Bell, M.
Pike, M. C.
.I 1373
.T
Gamma Function; Gamma Function for Range 1 to
2; Reciprocal Gamma Function to Real Argument;
Gamma Function; Logarithm of Gamma Function (Algorithms
34[S14]; 54[S14]; 80[S14]; 221[S14]; 291[S14])
.A
Pike, M. C.
Hill, I. D.
.I 1374
.T
Evaluation of Determinant; Determinant
Evaluation (Algorithms 41[F3]; 269[F3])
.A
Bergson, A.
.I 1375
.T
Function Minimization (Algorithm 251 [E4])
.A
Fletcher, R.
.I 1376
.T
Modified Graeffee Method (Algorithm 256 [C2])
.A
Stern, G.
.I 1377
.T
Pseudo-Random Numbers (Algorithm 266 [G5])
.A
Hansson, L.
.I 1378
.T
Pseudo-Random Numbers (Algorithm 266 [G5])
.A
Hill, I. D.
Pike, M. C.
.I 1379
.T
A Final Solution to the Dangling Else of ALGOL 60 and Related Languages
.W
The dangling else problem consists of a class
of potential ambiguities in ALGOL-like conditional
statements whose basic form is "if B1 then if B2 then
S1 else S2" where B1 and B2 are Boolean expressions
and S1 and S2 are basic statements.  The difficulty
lies in whether to attach the else to the first if
or to the second one.  Existing solutions to the problem
are either ambiguous or unnecessarily restrictive.
 Let Sand S1 be statements.  We define S to be closed
if "S else S1" is not a statement, and to be open
if "S else S1" is a statement.  Thus an unconditional
statement is  a closed statement.  Open and closed
conditional statements are defined by syntax equations
in such a way as to preserve openness and closure.
 In each case, an else must always be preceded by a closed
statement.  It is shown that the syntax equations
are unambiguous, and that may change in the statement
types required within the syntax equations would
lead to either ambiguity or unnecessary restriction.
.A
Abrahams, P. W.
.I 1380
.T
SIMULA-an ALGOL-Based Simulation Language
.W
This paper is an introduction to SIMULA, a
programming language designed to provide a systems
analyst with unified concepts which facilitate the
concise description of discrete event systems.  A
system description also serves as a source language simulation
program.  SIMULA is an extension of ALGOL
60 in which the most important new concepts
is that of quasi-parallel processing.
.A
Dahl, O. J.
Nygaard, K.
.I 1381
.T
Impact of Computers on the Undergraduate Mathematics Curriculum
.W
The use of computers to permit the widespread application
of mathematical ideas requiring computation
in science and technology is extremely significant for
the understanding of our current society.  Student
interest in this development is intense and if properly
utilized should yield a much better understanding
of mathematical concepts as well as the ideas of programming
and logical structure which have been introduced
into many fields by the use of computers.  The present
paper suggests that that portion of the undergraduate
mathematical curriculum which is preparation for the use
of mathematics by persons who are not professional
mathematicians be modified to include the extensions
and clarifications which are possible because of
computers.  An early introduction to programming is
desirable to permit a continuing use of automatic
computation to illustrate and clarify mathematical concepts.
 Following the calculus equation stage an
intensive introduction to numerical analysis should
be added to the current curriculum.  In addition
to providing competence in the mostly used computing
techniques, it would permit a more sophisticated
utilization of the advanced mathematical ideas associated
with complex variables and transform theories.
.A
Murray, F. J.
.I 1382
.T
Desired Computer Impact on Undergraduate Mathematics
.W
Three matters relating to the theme of the
Symposium are discussed here.  The author examines
some projections concerning the supply and demand for
mathematicians in the United States through the
mid-1970s, comments briefly on some of the factors which
may influence the professional activities of
applied mathematicians over the next several years,
and discusses in broad terms how this information
may relate to the undergraduate training of mathematicians.
.A
Macon, N.
.I 1383
.T
Implications of the Digital Computer
for Education In the Mathematical Sciences
.W
The digital computer has profoundly altered the
definition of what is interesting in mathematics.
 The importance of applied logic in human affairs is
changed by the existence of the "logical engine."
 The result is that one should no longer think in terms
of a single discipline of mathematics but in
terms of a complex of mathematical sciences.
.A
Givens, W.
.I 1384
.T
Mathematics for Undergraduate Computer Scientists
.W
The mathematical requirements for an undergraduate
program in Computer Science are a subject
of debate.  The Association for Computing Machinery's
Curriculum Committee, however, believes that these
requirements are essentially the same as the mathematical
content of physical sciences undergraduate
programs.  The Committee believes that these requirements
should assure the student of a broad mathematical
background and should enable him to take a wide variety
of courses in other scientific disciplines.
The Committee's concern is to develop a solid
scientific  approach to Computer Science.
.A
Atchison, W. F.
.I 1385
.T
Computer Technology in Communist China, 1956-1965
.W
Based on information from translations of Communist
Chinese news items and periodical literature
for the 1965 period, computer technology in China is
reviewed under the following headings: (1) initial
planning, organization and educational aspects of computer
technology and automation; (2) machine development
progress: two major specific machines in 1958-59, with
Soviet aid; a vacuum in 1960-64 due to the withdrawal
of Soviet aid; then presumably all-Chinese-made machines
from 1965 to the present; (3) computer applications;
(4) the trend of automation: control of production processes
rather than data processing; and (5) the
"Yun Ch'ou Hsueh" (Science of Operation and Programming)
campaign of 1958-60, during which an attempt
was made to bring concepts such as linear programming
to ordinary Chinese workers and peasants.  Communist
China is adjudged to have a marginal computer capability,
with most of its machines probably being of
a binary nature; however, a turning point may have been reached in mid-1965.
.A
Audette, D. G.
.I 1386
.T
Symbolic Factoring of Polynomials in Several Variables
.W
An algorithm for finding the symbolic factors of
a multi-variate polynomial with integer coefficients
is presented.  The algorithm is an extension of a technique
used by Kronecker in a proof that the prime
factoring of any polynomial may be found in a finite number
of steps.  The algorithm consists of factoring
single-variable instances of the given polynomial by
Kronecker's method and introducing the remaining
variables by interpolation.  Techniques for implementing the
algorithm and several examples are discussed.
 The algorithm promises sufficient power to be used efficiently
in an online system for symbolic mathematics.
.A
Jordan, D. E.
Kain, R. Y.
Clapp, L. C.
.I 1387
.T
Solution of Systems of Polynomial Equations By Elimination
.W
The elimination procedure as described by Williams
has been coded in LISP and FORMAC and used
in solving systems of polynomial equations.  It is found
that the method is very effective in the case
of small systems, where it yields all solutions without
the need for initial estimates. The method, by
itself, appears in appropriate, however, in the solution
of large systems of equation due to the explosive
growth in the intermediate equations and the hazards
which arise when the coefficients are truncated.
 A comparison is made with difficulties found in other
problems in non-numerical mathematics such as
symbolic integration and simplification.
.A
Moses, J.
.I 1388
.T
AUTOMAST: Automatic Mathematical Analysis and Symbolic Translation
.W
A procedure for numerically solving systems
of ordinary differential equation is shown to also
generate symbolic solutions.  The procedure is based
on a finite Taylor series expansion that includes
an estimate of the error in the final result.  A computer
program is described that reads in a system
of such equations and then generates the expansions
for all of the dependent variables. The expansions
are determined symbolically, hence any non-numeric parameters
in the original equations are carried automatically
into the final expansions.  Thus the exact influence
of any parameters on the problem solution can be
easily displayed.
.A
Ball, W. E.
Berns, R. I.
.I 1389
.T
A Programmer's Description of L^6
.W
Bell Telephone Laboratories' Low-Linked List Language
L^6 (pronounced "L-six") is a new programming
language for list structure manipulations.  It contains
many of the facilities which underlie such list
processors as IPL, LISP, COMIT ad SNOBOL, but permits
the user to get much closer to machine code in
order to write faster-running programs, to use storage
more efficiently and to build a wider variety
of linked data structures.
.A
Knowlton, K. C.
.I 1390
.T
CONVERT
.W
A programming language is described which
is applicable to problems conveniently described
by transformation rules.  By this is meant that patterns
may be prescribed, each being associated with
a skeleton, so that a series of such pairs may be searched
until a pattern is found which matches an
expression to be transformed.  The conditions for a match
are governed by a code which also allows subexpressions
to be identified and eventually substituted into the
corresponding skeleton.  The primitive patterns
and primitive skeletons are described, as well as the
principle which allow their elaboration in to more
complicated patterns and skeletons.  The advantages of the
language are that it allows one to apply transformation
rules to lists and arrays as easily as strings, that both
patterns and skeletons may be defined recursively,
and that as a consequence programs may be stated quite concisely.
.A
Guzman, A.
McIntosh, H. V.
.I 1391
.T
Computer Experiments in Finite Algebra
.W
A medium-scale programming system is written
in MAD and FAP on the IBM 7094 to manipulate some
of the objects of modern algebra: finite groups, maps
and sets of maps, subsets and sets of subsets,
constant integers and truth-values.  Designed to operate
in a time-sharing environment, the system can
serve as a teacher's aid to the undergraduate student of
modern algebra, as well as for the working scientist
or engineer wishing to familiarize himself with the subset.
.A
Maurer, W. D.
.I 1392
.T
Experience with FORMAC Algorithm Design
.W
Various facets of the design and implementation
of mathematical expression manipulation algorithms
are discussed.  Concrete examples are provided by the
FORMAC EXPAND and differentiation algorithms, a
basic FORMAC utility routine, and an experiment in the
extraction of the skeletal structure of an expression.
 One recurrent theme is the need to avoid excessive
intermediate expression swell in order to minimize
core storage requirements. Although many details from
the FORMAC implementation are presented, an attempt
is made to stress principles and ideas of general relevance
in the design of algorithms for manipulating
mathematical expressions.
.A
Tobey, R. G.
.I 1393
.T
PM, A System for Polynomial Manipulation
.W
PM is an IBM 7094 program system for formal manipulation
of polynomials in any number of variables,
with integral coefficients unrestricted in size.  Some
of the formal operations which can be performed
by the system are sums, differences, products, quotients,
derivatives, substitutions and greater common
divisors.  PM is based on the REFCO III list processing
system, which is described and compared with
the LISP and SLIP systems.  The PM subroutines for arithmetic
of large integers are described as constituting
an independently useful subsystem.  PM is compared with
the ALPAK system in several respects, including
the choice of canonical forms for polynomials.  A new
algorithm for polynomial greatest common divisor
calculation is mentioned, and exaples are
included to illustrate its superiority.
.A
Collins, G. E.
.I 1394
.T
Computation of Algebraic Properties of Elementary
Particle Reactions Using a Digital Computer
.W
A large number of calculations in high-energy
elementary particle physics involve the manipulation
of complicated algebraic expressions containing both
tensor and noncommutative matrix quantities.  Many
of these calculations take several months to complete, although
the operations involved follow straightforward
rules.  In this paper a program is described, which has
been developed in LISP for solving such problems.
 The manner in which these problems are encountered is
outlined, and their representation in the computer
discussed.  At present, about six months of human work
takes less than fifteen minutes on an IBM 7090.
 Limitations of the present system and future plans are also outlined.
.A
Hearn, A. C.
.I 1395
.T
On the Implementation of AMBIT, A Language for Symbol Manipulation
.W
A brief description is given of the implementation
technique for the replacement rule of the
AMBIT programming language.  The algorithm for the "AMBIT
scan" and an example of its application are
given.  The algorithm is applicable to other members
of the family of string transformation languages
of which AMBIT is a member, and it provides a rationale
for the design of the AMBIT language.
.A
Christensen, C.
.I 1396
.T
Survey of Formula Manipulation
.W
The field of formula manipulation is surveyed,
with particular attention to the specific capabilities
of differentiation, integration and the supporting capabilities
of simplification, displays and input/output
editing, and precision arithmetic.  General systems-both
batch and online-are described.  Finally, some
programs to solve specific applications are discussed.
.A
Sammet, J. E.
.I 1397
.T
Proceedings of the ACM Symposium on Symbolic and Algebraic Manipulation
.W
The ACM Symposium on Symbolic and Algebraic
Manipulation brought together over four hundred
people interested in programming languages designed
for manipulation of algebraic formulas and symbol
strings, in their applications, and in algorithms for
their implementation.  Twenty-eight papers were
presented, followed by a lively panel discussion of
future directions.  Evening meetings were arranged
for several interest groups.  The conference was sponsored
by the ACM Special Interest Committee on Symbolic
and Algebraic Manipulation.  The program committee consisted
of Chairman Jean E. Sammet, Paul Abrahams,
Thomas E. Cheatham, Max Goldstein, and Douglas Mcllroy.
 Conference arrangements were made by Lewis C.
Clapp, Daniel Bobrow and James H. Griesmer.-Robert W. Floyd, Editor
.I 1398
.T
Robot Data Screening: A Solution to Multivariate
Type Problems in the Biological and Social Sciences
.W
A new approach is outlined toward the solution
of the type of multivariate problem that is
found usually in the biological and social sciences as
well as in medicine.  This approach uses a "logical"
rather than a "statistical" criterion by which variables
are grouped into a deterministic model.  Algorithm
are developed by which some variables are kept on for
further analysis while others are eliminated.
Criteria for the acceptance of a variable as well as the
termination of the searching process are derived
from information theory.
.A
Sterling, T.
Gleser, M.
Haberman, S.
Pollack, S.
.I 1399
.T
On Top-to-Bottom Recognition and Left Recursion
.W
A procedure is given for obtaining structural
descriptions in a context-free grammar by performing
the recognition according to a strongly equivalent,
left-recursion-freegrammar. The effect of allowing
null strings in the rewriting rules is discussed.
.A
Kurki-Suonio, R.
.I 1400
.T
Free-Text Inputs to Utility Routines
.W
Through the use of some rather simple techniques,
it is frequently possible to produce a program
which will accept free-text inputs.  The techniques are
discussed and related to a general tape manipulation
routine.
.A
Blum, R. I.
.I 1401
.T
Quasilinearization and the Calculation of Eigenvalues
.W
Several eigenvalue problems for systems of
ordinary differential equations are considered.
 They are resolved computationally using the quasilinerization
technique, a quadratically convergent
successive approximation scheme related to
the Newton-Raphson-Kantorovich method.
.A
Bellman, R., Kagiwada, H.
Kalaba, R.
.I 1402
.T
Partial Step Integration
.W
A partial step integration equation is derived
for use with the Adams or Adams-Bashforth method
of integration of differential equations.  This method
of obtaining functional values at points intermediate
to the integration points yields accuracy comparable
to the integration and does not require storing
of additional information as in interpolation methods.
.A
Glauz, R. D.
.I 1403
.T
A Method for Finding the m Smallest Values of
a Monotonic Function Defined on Ordered Sets of
Positive Integers
.W
The minimum value of a monotonic increasing
function defined on a partially ordered set S is
assumed on the set of minimal points of S.  This observation
is used to devise an efficient method for
finding the m smallest functional values of monotonic
functions defined on ordered pairs of positive
integers.  The method is easily extended to include
monotonic functions defined on ordered n-tuples.
 Included is a FORTRAN program which was written to implement
the procedure for a certain important case.
.A
Sigillito, V. G.
.I 1404
.T
Computational Aspects of Multiple Covariance
Analysis on a Multifactor Structure
.W
The computational procedure for the analysis
of multiple covariance in statistics is discussed
with reference to the analysis of variance.  A special
operator calculus developed by Hartly for programming
analysis of variance for multifactor experiments is extended
to cover the analysis of covariance.  This
extension is accomplished by utilizing the connection
between the analysis of covariance and the analysis
of variance and by introducing a new operator.  The
results are illustrated by a numerical example for
analysis of covariance, in which the basic computations
are shown to be carried out by an analysis-of-variance
program.
.A
Peng, K. C.
.I 1405
.T
Matrix Triangulation with Integer Arithmetic (Algorithm 287 [F1])
.A
Blankinship, W. A.
.I 1406
.T
Solution of simultaneous Linear Diophantine
Equations (Algorithm 288 [F4])
.A
Blankinship, W. A.
.I 1407
.T
Confidence Interval for a Ratio (Algorithm 289 [G1])
.A
Hill, I. D.
Pike, M. C.
.I 1408
.T
The Eschenbach Drum Scheme
.W
The prime function of a drum, operating in
real time, is to perform accesses quickly.  The
usual means for increasing this capacity is to incorporate
engineering or hardware improvements.  In
this paper the problem is attacked not by changing the
drum, but rather by modifying the manner in which
it operates.  At the outset, a drum is given a functional
definition.  Then a simple design scheme (Eschenbach)
is introduced which enormously increases the rate of
accessing for drums so defined.  This is shown to
enable a system to perform a job by employing fewer or
less expensive drums.  It is suggested that although
the design scheme has a specific use, the method underlying it
has more general applicability.  The question
of the efficacy of the drum scheme is then raised.  To
deal with this, a standard of efficiency is developed
in light of realistic real-time circumstances.  The drum
scheme is then modelled in a manner which permits
it to be analyzed as a problem in queueing theory.
Thus one is enabled to ascertain whether the drum
scheme is efficient enough for its application.  Again,
whereas the analysis of the drum scheme has a
specific use, the methods underlying it have more general applicability.
.A
Weingarten, A.
.I 1409
.T
NEBULA: A Digital Computer Using a 20 Mc Glass Delay Line Memory
.W
Oregon State University has designed and constructed
a medium-speed serial digital computer
using glass delay lines circulating at 22 Mc as memory.
 The design objectives as originally conceived
in a special seminar were: (1) to be a research project
in computer design; (2) to be usable as an educational
machine;and (3) to have easily modifiable hardware for
basic research in computer systems design.  An
unusual arrangement of information within the 22 Mc
memory allows a simple interface with the 340 Kc
arithmetic unit, which results in an effective zero latency
time and provides possibilities for an associative
memory.  The arithmetic unit has a command structure similar
to large parallel machines, and uses flip-flop
arithmetic and control registers throughout.  All hardware
development has been aimed toward the concept
of easy modification, elaborate console controls for
effective man-machine interaction and low cost.
.A
Boles, J. A.
Rux, P. T.
Weingarten Jr., F. W.
.I 1410
.T
Interarrival Statistics for Time Sharing Systems
.W
The optimization of time-shared system performance
requires the description of the stochastic
processes governing the user inputs and the program activity.
 This paper provides a statistical description
of the user input process in the SDC-ARPA general-purpose
Time-Sharing System (TSS).  The input process
is assumed to be stationary, and to be defined by the
interarrival time distribution.  The data obtained
appear to justify satisfactorily the common assumption
that the interarrival times are serially independent.
 The data do not appear to justify, except as a very
rough approximation, the usual assumption off an
exponential distribution for interarrival time.  A much
more satisfactory approximation to the data can
be obtained with a biphase or triphase hyperexponential distribution.
.A
Coffman, E. G.
Wood, R. C.
.I 1411
.T
Comparison of Several Algorithms for Computation
of Means, Standard Deviations and Correlation
Coefficients
.W
Several algorithms for computation of basic
statistics are compared by their performance on
systematically generated test data.  The statistics
calculated were the mean, standard deviation and
correlation coefficient.  For each statistic, the algorithm
included the usual computing formulas, correction
due to an accumulated error term, and a recursive computation
of the current value of the statistic.
 The usual computing formulas were also evaluated in
double precision.  Large errors were noted for some
calculation using the usual computing formulas.  The most
reliable technique was correction of the initial
estimate by use of an accumulated error term.  To eliminate
the need for making two passes on the data,
it was suggested that the initial estimate of the
mean be obtained from a subset of the data.
.A
Neely, P. M.
.I 1412
.T
The Banking Information System Concept
.W
Most large commercial banks have progressed to
the  point where their major accounting applications
have been automated and more sophisticated usage of
data processing equipment is being sought.  This,
coupled with the availability of equipment well suited
to real-time, direct access processing,has led
to development within some banks of the central file
of data base approach toward a banking information
system.  The banking information system now serves the
two-fold purpose of providing real-time responses
to inquires about individual account stasus and providing
more complex combinations of information for
management use.  Both kinds of processing draw upon a
common store of data contained in the direct access
central file.  This data base includes indexes which
facilitate cross referencing of account information
so that all relationships between bank and customer may
be discerned.  In introducing the banking information
system concept, a gradual approach to account cross-referencing
and file conversion is most prudent.
 Generally, this system must interface with other computer
applications already existing within the bank.
.A
Head, R. V.
.I 1413
.T
A Vision of Technology and Education
.W
Educational technology is currently quite
fashionable.  Here, as in many other branches or
aspects of technology, changes possible in the next generation
or two are now known as ideas, discoveries
or inventions.  The unknown is whether the potential
will become the actual and, if so, on what time
scale.  This ignorance stems largely from ignorance about
the social response to potential technological
change.  The object of this paper is to present a vision
of potential educational technology and to raise
questions about the modes of social response and
adaptation likely to be evoked by such a vision.
.A
Oettinger, A. G.
.I 1414
.T
Twelve-Row Punched-Card Code for Information
Interchange* (Proposed American Standard)
.I 1415
.T
Automatic Derivation of Microsentences
.W
The decomposition of long complex English sentences
into shorter kernel-like constituent sentences
(microsentences)has often been suggested as an avenue
toward conducting automatic retrieval of natural
language messages.  To explore the prospects of such
a step, the authors attempted in 1963 to prepare
a general program for deriving microsentences from longer
sentences that had been syntactically analyzed
by the Harvard Multipath Analysis Program.  The basic
idea was to extract the subject, verb and object
(if any) of each clause and to reassemble these materials
into a grammatical microsentence.  A program
is described in this paper, which was designed to operate
on the tree structure output of the analyzer,
and the microsentences that were produced are exhibited.
 The authors conclude that while microsentences
of the quality achieved do not open up immediate prospects
for improving the performance of automatic
message retrieval systems, they may have practical
value in man-machine systems using human monitors
to select the preferred syntactic interpretation of a sentence.
.A
Carmody, B. T
Jones Jr., P. E.
.I 1416
.T
A Fortran Technique for Simplifying Input to Report Generators
.W
Typical report generators allow the production
of standard forms when tabulating a magnetic
tape file; the extraction of nonstandard sets of information,
with suitable annotation, involves troublesome
forms design.  A method of information extraction involving
the calculation of suitable FORTRAN FORMAT
statements, which combats this problem, is described.
.A
Cleary, J. G.
.I 1417
.T
Economies of Scale and the IBM System/360
.W
Cost functions among five System/360 models
are analyzed through examinations of instruction
times, program kernels and a "typical" instruction mix.
 Comparisons are made between the data developed
here and Grosch's Law which seems to be applicable to
much of the data.  Sizable economies of scale are
unquestionably present in computing equipment.
.A
Solomon Jr., M. B.
.I 1418
.T
Examination Scheduling (Algorithm 286 [ZH])
.A
Peck, J. E. L.
Williams, M. R.
.I 1419
.T
Chebyshev Quadrature (Algorithm 279 [D1])
.A
Hopgood, F. R. A.
Litherland, C.
.I 1420
.T
A New Uniform Pseudorandom Number Generator
.W
A new multiplicative congruential pseudorandom
number generator is discussed, in which the
modulus is the largest prime within accumulator capacity
and the multiplier is a primitive root of that
prime.  This generator passes the usual statistical
tests and in addition the least significant bits
appear to be as random as the most significant bits-a
property which generators having modulus 2^k do
not possess.
.A
Hutchinson, D. W.
.I 1421
.T
A Contribution to the Development of ALGOL
.W
A programming language similar in many respects
to ALGOL 60, but incorporating a large number
of improvements based on six years experience with that
language, is described in detail.  Part I consists
of an introduction to the new language and a summary
of the changes made to ALGOL 60, together with a
discussion of the motives behind there visions.  Part II
is a rigorous definition of the proposed language.
 Part III describes a set of proposed standard procedures
to be used with the language, including facilities
for input/output.
.A
Wirth, N.
Hoare, C. A. R.
.I 1422
.T
Eleven-Sixteenths Inch Perforated
Paper Tape (Proposed American Standard)
.I 1423
.T
A Simple Algorithm for Computing the Generalized Inverse of a Matrix
.W
The generalized inverse of a matrix is important
in analysis because it provides an extension
of the concept of an inverse which applies to all matrices.
 It also has many applications in numerical
analysis, but it is not widely used because the existing
algorithms are fairly complicated and require
considerable storage space.  A simple extension has
been found to the conventional orthogonalization
method for inverting non-singular matrices, which gives
the generalized inverse with little extra effort
and with no additional storage requirements.  The algorithm
gives the generalized inverse for any m by
n matrix A, including the special case when m+n and A
is non-singular and the case when m>n and rank(A)
= n.  In the first case the algorithm gives the ordinary
inverse of A.  In the second case the algorithm
yields the ordinary least squares transformation matrix
INV(A'A)A' and has the advantage of avoiding
the loss of significance which results in forming the product A'A explicitly.
.A
Rust, R.
Burrus, W. R.
Schneeberger, C.
.I 1424
.T
Automatic Analysis of Electronic Digital Circuits Using List Processing
.W
A mapping from black diagrams of digital circuits
to list structures is described, together
with a list processing program written for the Control
Data 3600 which uses this mapping to automatically
carry out circuit analysis.
.A
Shalla, L.
.I 1425
.T
Flow Diagrams, Turing Machines And
Languages With Only Two Formation Rules
.W
In the first part of the paper, flow diagrams
are introduced to represent inter al. mappings
of a set into itself.  Although not every diagram is
decomposable into a finite number of given base
diagrams, this becomes true at a semantical level due
to a suitable extension of the given set and of
the basic mappings defined in it.  Two normalization
methods of flow diagrams are given.  The first has
three base diagrams; the second, only two.  In the second
part of the paper, the second method is applied
to the theory of Turing machines.  With every Turing
machine provided with a two-way half-tape, there
is associated a similar machine, doing essentially
the same job, but working on a tape obtained from
the first one by interspersing alternate blank squares.
 The new machine belongs to the family, elsewhere
introduced, generated by composition and iteration from
the two machines L and R.  That family is a proper
subfamily of the whole family of Turing machines.
.A
Bohm, C.
Jacopini, G.
.I 1426
.T
A Simulation of Hospital Admission Policy
.W
A study is described which simulates different
admission policies of a large specialized hospital.
 The objective is to determine better policies for
stabilization of admission and census rates while
maintaining a reasonably full hospital.  There types of
policies were examined: admission based on percentages
of discharge rates, discharge rates plus or minus a
constant, and fixed authorizations independent of
discharge rates.  The last type policy produced more stable
simulated results, and when put into practice,
improvements were realized.
.A
Smith, W. G.
Solomon Jr., M. B.
.I 1427
.T
Simulation of Radioisotope Scans by Computer
.W
In radioisotope scanning, a field which is assuming
increasing importance in medical diagnosis,
the scan is a two-dimensional pattern made up of dots.
 Areas of increased source activity are represented
on the scan by areas of increased dot density.  To study
the output of scanners with various characteristics,
a program which simulates radioisotope scans has been
written  for a PDP-1 computer with auxiliary disk
storage and cathode ray tube display.  Past and present
research using the output of the simulator has
shown the flexibility of the system to be important.
 The structure of this program can be useful in
the simulation of the output of any quantum-limited system.
.A
Pizer, S. M.
.I 1428
.T
SHOCK III, A Computer System As an Aid
in the Management of Critically III Patients
.W
SHOCK III, an online digital computer system
to assist the physician, nurse and paramedical
personnel in monitoring and reporting on critically ill patients, is described.
.A
Rockwell Jr., M. A.
Shubin, H.
Weil, M. H.
Meagher, P. F.
.I 1429
.T
Matrix Reduction Using the Hungarian Method
For The Generation of School Timetables
.W
The application of Kuhn's Hungarian Method
to the problem of matrix reduction as needed in
Gotlieb's method for timetable generation is described.
 The method is suited to both hand and computer
calculation.  Devices to improve the efficiency
of the basic algorithm are discussed.
.A
Lions, J.
.I 1430
.T
Multiple Precision Floating-Point Conversion
from Decimal-to-Binary and Vice Versa
.W
Decimal-to-binary and binary-to-decimal floating-point
conversion is often performed by using
a table of the powers 10^i, (ia positive integer) for
converting from base 10 to base 2, and by using
a table of the coefficient of a polynomial approximation
of 10^x, (0<=x<1) for converting from base 2
to base 10.  These tables occupy a large storage region
in the case of a nonsingle precision conversion.
 This paper shows that a single small table suffices
for a floating-point conversion from decimal to
binary, and vice versa, in any useful precision.
.A
Mancino, O. G.
.I 1431
.T
On a Storage Mapping Function For Data Structures
.W
Some basic facts about certain data structures
are reviewed and an efficient algorithm is presented
for constructing a storage mapping function for
a structure from the structure's definition.
.A
Deuel, P.
.I 1432
.T
Incorporation of Nonstandard Input/Output Devices into FORTRAN Systems
.W
A FORTRAN system may readily be modified to
handle input/output with nonstandard media on the
same basis on which it handles the standard media.  This
is done by providing a character-handling subroutine
suited to the nonstandard medium and arranged to be called
by an otherwise unused output statement type
or unit number. This method was used to control output
of alphanumeric information on a digital graph
plotter.
.A
Cohn, C. E.
.I 1433
.T
A Note on Linear Programming Algorithm Design: A Combinatorial Problem
.W
As linear programming models grow bigger and
bigger in size, much actual data that must be
memorized is often put on magnetic tape or disk, and
consequently there is an improportionality fast
rise in the consumption of computer time.To cut down
this expense, an ever increasing effort is made
to design more efficient algorithms.  This paper is
meant to support the effort.  It is attempted to
find some characteristics of the way a pivot column
is found.  The number of repetitions of a certain
transfer of data from tape to core memory is considered.
 After some simplification, the problem is restated
in a general way.  The generating function of the probability
distribution and the moment generating
function of the number of repetitions is found.  Asymptotic
formulas are given for the moments using
a result from a paper of S. Narumi [1].  The results
may be applied to write very efficient routines
that search for an extreme value in a table.  Formulas
provide a means of calculating the computer timings
in this case.
.A
Roes, P. B. M.
.I 1434
.T
A Monte Carlo Algorithm for Assigning Students to Classes
.W
A technique of random choice is illustrated
by application to the problem of assigning students
to a fixed schedule of courses.  Using the technique
it is possible to reduce or eliminate difficulties
that result when a popular section is filled and closed
before all students requesting and requiring
it have been scheduled.  The effectiveness of automatic
scheduling is retained without loss of the students
privilege of picking favorite instructors.
.A
Macon, N.
Walker, E. E.
.I 1435
.T
Design of Computer Simulation Experiments for Industrial Systems
.W
The aim of this paper is to provide background
information on the existing literature on experimental
design techniques which may be applicable to the design
of computer simulation experiments for industrial
systems.  Although major emphasis is placed on analysis
of variance techniques, three other techniques
of data analysis are considered-multiple ranking procedures,
sequential sampling and spectral analysis.
 The paper treats four specific experimental design
problems and several techniques for solving them.
 The four experimental design problems are: (1) the
problem of stochastic convergence, (2) the problem
of factor selection, (3) the problem of motive
and (4) the many response problem.
.A
Burdick, D. S.
Naylor, T. H.
.I 1436
.T
Interchange of Two Blocks of Data (Algorithm 284 [K2])
.A
Fletcher, W.
.I 1437
.T
The Mutual Primal-Dual Method (Algorithm 285 [H])
.A
Aird, T. J.
.I 1438
.T
A Method for Locating Zeros of Complex Functions
.W
A method for computing the index, or winding
number, is developed and applied to the problem
of finding zeros of functions from the plane into the plane.
.A
Cain Jr., G. L.
.I 1439
.T
Mechanization of the Curve Fitting Process: DATAN
.W
A process for fitting a curve to approximate data
and the problem it creates for the engineer-programmer
is defined.  An approach has also been defined and a system
has been written for the SRU 1107 to mechanize
a major portion of this process.  The techniques developed
to accomplish the mechanization are largely
empirical, and are dependent for their information
only on the actual data points.
.A
Simonsen, R. H.
Anketell, D. L.
.I 1440
.T
Starting Approximations for Square Root Calculation on IBM System/360
.W
Several starting approximations for square
root calculation by Newton's method are presented
in a form to facilitate their use in IBM System/360 square
root routines.  These approximations include
several for the range [1/16, 1], which is the interval
of primary interest on IBM System/360.
.A
Fike, C. T.
.I 1441
.T
Methods of Numerical Integration Applied to
a System Having Trivial Function Evaluations
.W
A study has been made to determine which methods
of numerical integration require the least
computation time for a given amount of truncation error
when applied to a particular system of ordinary
differential equations where function evaluations are
relatively trivial.  Recent methods due to Butcher
and Gear are compared with classic Runge-Kutta, Kutta-Nystrom
and Adams methods.  Some of the newer one-step
methods due to Butcher are found to be slightly superior,
but no one method is found to have any great
advantage over the others in the application to this particular problem.
.A
Waters, J.
.I 1442
.T
Recorded Magnetic Tape For Information Interchange
(800 CPI, NRZI)* (Proposed American Standard)
.I 1443
.T
A Method for Finding the Least Squares Estimate
of the Intersection Point of Two Helices in Space
.W
When the helical trajectories of two charged
particles moving away from a common point in a
magnetic field are reconstructed from measurements on
the tracks, the reconstructed tracks are perturbed
by measurement and other errors and do not, in general,
intersect.  A method is given for adjusting the
reconstructed tracks in a least squares manner so that they do intersect.
.A
Royston, R. J.
Gregory, J.
.I 1444
.T
An Algorithm for Generating Projective Reduction
Formulas for Matrix Elements of Many-Electron
Wavefunctions
.W
An ALGOL procedure is given for automatically
generating formulas for matrix elements arising
in the variational solution of the Schrodinger
equation for many-electron systems.
.A
Reeves, C. M.
.I 1445
.T
Use of the Computer to Teach Introductory Statistics
.W
It has always been obvious that the aid to calculation
offered by the computer forces a change
in the curricula of mathematics, statistics, physics,
engineering and other courses.  Not so obvious
are the many pedagogic aids the computer can offer in
teaching the subject matter.  The possibilities
of giving the student a better technical as well as conceptual
understanding of statistics were explored
for a number of years at the College of Medicine of
the University of Cincinnati and are reported here.
.A
Sterling, T. D.
Pollack, S. V.
.I 1446
.T
Chebyshev Quadrature (Algorithm 279 [D1])
.A
Hopgood, F. R. A.
Litherland, C.
.I 1447
.T
Abscissas and Weights for Gregory Quadrature [D1])
.A
Welsch, J. H.
.I 1448
.T
Abscissas and Weights for Romberg Quadrature (Algorithm 281 [D1])
.A
Welsch, J. H.
.I 1449
.T
Derivatives (Algorithm 282 [S22])
.A
Gautschi, W.
.I 1450
.T
Simultaneous Displacement of Polynomial
Roots if Real and Simple (Algorithm 283 [C2])
.A
Kerner, I. O.
.I 1451
.T
Runge-Kutta Integration (Algorithm 9 [D2])
.A
Thacher Jr., H. C.
.I 1452
.T
Kutta-Merson (Algorithm 218 [D2]
.A
Bayer, G.
.I 1453
.T
A Nonrecursive Method of Syntax Specification
.W
The use of the Kleene regular expression notation
for describing algebraic language syntax,
in particular of ALGOL, is described in this paper.
A FORTRAN II computer program for carrying out the
elimination algorithm of Gorn,similar to Gaussian elimination
for linear systems of algebraic equations,
is described.  This was applied to numerous smaller
languages, including some sublanguage of ALGOL.
A hand calculation result of the application of the algorithm
to all of ALGOL is given, thus expressing
the Revised ALGOL 1960 syntax in completely nonrecursive
terms, as far as its context-free portion is
concerned.  This description in many ways is far more
intuitively understood than the previous recursive
description, it is suggested.  The paper also includes
results of the machine program, which does not
include a simplification algorithm.
.A
Carr III, J. W.
Weiland, J.
.I 1454
.T
A Simple User-Oriented Compiler Source Language
for Programming Automatic Test Equipment
.W
For the nonprogrammer, difficulty in using
a language increases rapidly with the number of
nonproblem-oriented conventions.  A simple language, even
if inelegant, which considers the user's background
as part of the problem may be more effective than a source
language containing subtle and more powerful
capabilities.  The language described in this paper is
used to write computer programs which test electronic
equipment.  Because this testing process contains few
complex ideas, there is little need for the elegance
and redundancy of a highly syntax-oriented language.
 A simple and direct language will suffice for the
problem.  The eventual users of this language are military
depot personnel who cannot he expected to
have computer programming skill or significant programming
training.  For this nonprogramming-oriented
user, it was essential to create a language using familiar
engineering statements; programming-oriented
conventions would have unnecessarily complicated his task.
.A
Scheff, B. H.
.I 1455
.T
TRAC, A Procedure-Describing Language for the Reactive Typewriter
.W
A description of the TRAC (Text Reckoning
And Compiling) language and processing algorithm
is given.  The TRAC language was developed as the basis
of a software package for the reactive typewriter.
 In the TRAC language, one can write procedures for
accepting, naming and storing any character string
from the typewriter; for modifying any string in any way;
for treating any string at any time as an executable
procedure, or as a name, or as text; and for printing
out any string.  The TRAC language is based upon
an extension and generalization to character strings
of the programming concept of the "macro."  Through
the ability of TRAC to accept and store definitions of
procedures, the capabilities of the language can
be indefinitely extended, and can deal with character
strings, integers and Boolean vector variables.
.A
Mooers, C. N.
.I 1456
.T
Storage and Retrieval of Aspects of Meaning in Directed Graph Structures
.W
An experimental system that uses LISP to make
a conceptual dictionary is described.  The dictionary
associates with each English word the syntactic information,
definitional material, and references to
the contexts in which it has been used to define other words.
 Such relations as class inclusion, possession,
and active or passive actions are used as definitional
material.  The resulting structure serves as a
powerful vehicle for research on the logic of question answering.
 Examples of methods of inputting information
and answering simple English questions are given.  An
important conclusion is that, although LISP and
other list processing languages are ideally suited for
producing complex associative structures, they
are inadequate vehicles for language processing on any
large scale-at east until they can use auxiliary
memory as a continuous extension of core memory.
.A
Simmons, R. F.
.I 1457
.T
Data Manipulation and Programming Problems
in Automatic Information Retrieval
.W
Automatic information retrieval programs require
the manipulation of a variety of different
data structures, including linear text, sparse matrices,
and tree or list structures.  The main data
manipulations to be performed in automatic information
systems are first briefly reviewed.  A variety
of data representations which have been used to describe
structured information are then examined, and
the characteristics of various processing languages are
outlined in the light of the procedures requiring
implementation.  Advantages of these programming languages
for the retrieval application are examined,
and suggestions are made for the design of programming
facilities to aid in information retrieval.
.A
Salton, G.
.I 1458
.T
Online Programming
.W
When the transition has been made from off line
to online programming, there are a number of
changes in the working conditions noted.  These changes
in the environment make necessary corresponding
changes in the processes related to producing and checking
out programs.  In the main, it it not the
programming language itself which must be changed to
provide a facility for the online user; it is the
system surrounding the programming language.  In this
paper the online environment and its effect on
programming are discussed.
.A
Schwartz, J. I.
.I 1459
.T
Requirements for Real-Time Languages
.W
Real-time languages have different requirements
from other programming languages because of
the special nature of their applications, the environment
in which their object programs are executed
and the environment in which they may be compiled.  It
may not be the language extensions that ultimately
advance developments in the field.  Progress may be made
by attacking the special compiling and executing
system problems that must be solved.
.A
Opler, A.
.I 1460
.T
Evolution of the Meta-Assembly Program
.W
A generalized assembler called a "meta-assembler"
is described.  The meta-assembler is defined
and factors which contributed to its evolution are presented.
 How a meta-assembler is made to function
as an assembly program is described. Finally, the implication
of meta-assemblers on compiler design is
discussed.
.A
Ferguson, D. E.
.I 1461
.T
Discussion Summary on Operating Systems
.I 1462
.T
Multilevel Operating Systems
.W
The Basic software for all newer computers
is built on the well-established need for standard
operating systems. This implies that all applications-no
matter how large, complex or time consuming-must
operate under (or, more precisely, on top of) the standard
system.  Large applications require supervisory
monitors which handle problems similar to those of
the operating systems, but at a different level.
Sometimes, still a third or even a fourth such level
is required or desirable.  This leads naturally
to the concept of multilevel systems-similar vertically,
but different horizontally.  Proper division
of responsibility between levels leads to greater efficiency and
less logical complexity, while actually
enhancing capability.
.A
Orchard-Hays, W.
.I 1463
.T
More on Extensible Machines
.W
One of the most salient characteristics of extensible
machines (EM) is the facility for providing
system control over program-to-program and program-to-data
linkage (e.g., address connection).  It is
the intent of this paper to expand and clarify the remarks
concerning program-to-program and program-to-data
linkage that were embodied in the authors' previous
paper on the EM concepts, and to, finally, trace
the employment of linkage mechanisms through
various levels of programming languages.
.A
Leonard, G. F.
Goodroe, J. R.
.I 1464
.T
An ALGOL Compiler: Construction and Use
in Relation to an Elaborate Operating System
.W
An ALGOL translator has been prepared and integrated
into the IBSYS Operating System.  Assembly
and "go" features of IBSYS permit immediate execution with
optional listings, decks and debugging information.
 Using the chain feature of IBSYS, links written in
MAP or FORTRAN as well as ALGOL may be called by
the ALGOL main program.  In addition, procedures coded
in MAP may be included in any ALGOL program.
Although assembly plus loading time exceeds compilation
time, the total time is satisfactory and the
user gets ease and facility which are fully compensating.
.A
Boussard, J. C.
.I 1465
.T
Program Translation Viewed as a General Data Processing Problem
.W
Efficiency dictates that the overall effectiveness
of a compiler be increased by all means
available.  For a compiler to have a substantial useful
life it needs a clear logical structure, reliability
and sound data processing techniques.  A compiler must
be based on fixed conventions to preserve efficiency
and reliability; empty options and default conventions
violate this dictum.  Use of structure to associate
various parts of a program and economy of
features promote clarity and reliability.
.A
Naur, P.
.I 1466
.T
Discussion Summary on Graphical Languages
.I 1467
.T
A Graphical ServiceSystem With Variable Syntax
.W
Man-machine interaction in many fields of endeavor
should be greatly facilitated in the near
future through the use of interactive graphical languages.
 To provide a variety of display scope communication
procedures, a Graphic Service system which functions
as a generalized graphical language translator,
is being developed to aid the definition as
well as the use of new graphical languages.
.A
Roberts, L. G.
.I 1468
.T
Syntax-Directed Interpretation of Classes of Pictures
.W
A descriptive scheme for classes of pictures based
on labeling techniques using parallel processing
algorithms was proposed by the author some years ago.
 Since then much work has been done in applying
this to bubble chamber pictures.  The parallel processing
simulator, originally written for an IBM 7094
system, has now been rewritten for a CDC 3600 system.
 This paper descriptive models by considering their
specific application to bubble chamber pictures.  How
the description generated in this phase can be
embedded in a larger "conversation" program is explained
by means of a certain specific example that
has been worked out.  A partial generative grammar for
"handwritten" English letters is given, as are
also a few computer-generated outputs using this grammar
and the parallel processing simulator mentioned
earlier.
.A
Narasimhan, R.
.I 1469
.T
The Next 700 Programming Languages
.W
A family of unimplemented computing languages
is described that is intended to span differences
of application area by a unified framework.  This framework
dictates the rules about the uses of user-coined
names, and the conventions about characterizing functional
relationships.  Within this framework the
design of a specific language splits into two independent
parts.  One is the choice of written appearances
of programs (or more generally, their physical representation).
 The other is the choice of the abstract
entities (such as numbers, character-strings, lists
of them, functional relations among them) that can
be referred to in the language.  The system is biased
towards "expressions" rather than "statements."
 It includes a nonprocedural(purely functional) subsystem
that aims to expand the class of users' needs
that can be met by a single print-instruction, without sacrificing
the important properties that make
conventional right-hand-side expressions easy to construct and understand.
.A
Landin, P. J.
.I 1470
.T
The Structure of Programming Languages
.W
The following are identified as major components
of every programming language: (1) the elementary
program statement, (2) mechanisms for linking elementary
statements together, (3) the means by which
a program can obtain data inputs.  Several alternative
forms of each of these components are described,
compared and evaluated.  Many examples, frequently from
list processing languages, illustrate the forms
described.  Elementary program statements usually take
the form of commands, requirements, or implicit
specifications.  A command is an imperative statement
that commands the action to be taken.  A requirement
describes the effect to be achieved without saying anything
about the actions to be taken.  An implicit
specification is similar to a requirement, but the programmer
must understand what actions will be taken
to achieve the desired effect.  Subroutines may be entered
explicitly, by execute call, or by function
composition.  Explicitly called subroutines generally
require special linkage conventions.  An execute
subroutine call is syntactically indistinguishable from
a basic instruction of the programming language.
 Function composition is a convenient alternative to
the explicit call.  The three principal ways of
getting inputs for routines are (1) by referring to
the data itself, (2) by referring to the data by
a "name", and (3) by referring to it implicitly by means
of variables or functions.  Names are useful
entry points into permanent data structures, but can
be error-causing distractions in other contexts.
The author discusses advantages, disadvantages, and factors
influencing the choice of a form of component
for a language.   He concludes by suggesting the evolution
of programming languages toward one which
will permit all the most convenient ways of structuring
programs, organizing systems, and referencing
data.
.A
Raphael, B.
.I 1471
.T
Programming Semantics for Multiprogrammed computations
.W
The semantics are defined for a number of meta-instructions
which perform operation essential
to the writing of programs in multiprogrammed computer
systems.  These meta-instructions relate to parallel
processing, protection of separate computations, program
debugging, and the sharing among users of memory
segments and other computing objects, the names of which
are hierarchically structured.  The language
sophistication contemplated is midway between an assembly
language and an advanced algebraic language.
.A
Dennis,J. B.
VanHorn, E. C.
.I 1472
.T
Description of a High Capacity, Fast
Turnaround University Computing Center
.W
The operating system for the UNIVAC 1107 at Case
Institute is reviewed.  The system is of interest
because of the low turnaround times achieved, the high
throughput achieved and the lack of an operating
staff.  Turnaround times below 5 minutes and job volume
above 75,000 per quarter year one reported.
.A
Lynch, W.C.
.I 1473
.T
The Stability of the Fourth Order Runge-Kutta
Method for the Solution of Systems of Differential
Equations
.W
The problem of the region of stability of the
fourth order-Runge-Kutta method for the solution
of systems of differential equations is studied.  This
region can be characterized by means of linear
transformation but can not be given in a closed form.
 In the paper, this region is determined by the
electronic digital computer Z22.
.A
Karim, A. I. A.
.I 1474
.T
Tests of Probabilistic Models for Propagation of Roundoff Errors
.W
In any prolonged computation it is generally
assumed that the accumulated effect of roundoff
errors is in some sense statistical.  The purpose of this
paper is to give precise descriptions of certain
probabilistic models for roundoff error, and then to
describe a series of experiments for testing the
validity of these models.  It is concluded that the models
are in general very good.  Discrepancies are
both rare and mild.  The test techniques can also be
used to experiment with various types of special
arithmetic.
.A
Hull, T. E.
Swenson, J. R.
.I 1475
.T
Dribble Posting a Master File
.W
Many business applications employ sequential
magnetic tape rather than random-access storage
techniques to process a very small number of transactions
against a voluminous master file.  In such
situations, it may prove economical to avoid creating a
new master file during each updating run by producing
instead a dribble ledger containing only those master
file accounts which have experienced activity.
.A
Head, R. V.
.I 1476
.T
Control Procedures for Data Communication-An ASA Progress Report
.W
Sectional Committee X.3 of the American Standards
Association, has charged one of its task
groups, X3.3.4, with the responsibility to "Define and specify
functional control requirements and characteristics
governing the operation of digital data generating and
receiving systems interconnected by communication
system."  This effort is primarily directed toward systems
employing the American Standard Code for Information
Interchange (ASCII).  This paper represents a progress
report on the work of this group toward a proposal
for national and international standardization in the
field of control procedures.  It describes both
the old and new work of the task group.  The new work
is presented in detail, while the work that has
been presented in earlier papers ["Control Procedures for
Data Communication," Task Group document X3.3.4/44,
May 1964: "Transparent-Mode Control Procedures for Data
Communication," Task Group document X3.3.4/58,
December, 1964: Comm. ACM 8 (Apr. 1965), 203-206; "Control
Procedures for Data Communications," Task
Group document X3.3.4/60, March, 1965] is retained here
in summary form.  Many of the concepts and principles
described herein have been submitted to the International
Organization for Standardization via earlier
papers and are now embodied in working papers of that organization.
.I 1477
.T
EULER: A Generalization of ALGOL, and its Formal Definition: Part II*
.A
Wirth, N.
Weber, H.
.I 1478
.T
Exponential Curve Fit (Algorithm 275 [E2])
.A
Deily, G. R.
.I 1479
.T
Constrained Exponential Curve Fit (Algorithm 276 [E2])
.A
Deily, G. R.
.I 1480
.T
Computation of Chebyshev Series Coefficients (Algorithm 277[C6])
.A
Smith, L. B.
.I 1481
.T
Graph Plotter (Algorithm 278 [J6])
.A
Lloyd, P.
.I 1482
.T
BUGSYS: A Programming System for Picture Processing-Not for Debugging
.W
BUGSYS is a picture processing and measuring
system that depends upon a pictorial input to
the computer's memory.  BUGSYS can be used for many
types of applications.  In particular, the authors
have used the system for the analysis of linear graphs.
 The main concept of the system is the use of
a collection of programmable pointers, which
are visualized as a family of "bugs."
.A
Ledley, R. S.
Jacobsen, J.
Belson, M.
.I 1483
.T
A Comparison of the FORTRAN Language
Implementation for Several Computers
.W
A feature-by-feature comparison is made of five
different implementations of FORTRAN IV representing
three different manufacturers.  A table is constructed
showing, where possible, the use of each feature
in each implementation.  Only those items which are
different from, or have been added to FORTRAN II
are shown.
.A
Wright, D. L.
.I 1484
.T
A Language for Describing the Functions of Synchronous Systems*
.W
Before the design of a system is started, the
exact function desired of it should be specified.
 It is suggested that a computer-oriented language be
used for this purpose.  The inadequacies of the
standard programming languages for the description of
systems are discussed, and a dialect of ALGOL which
is suitable for describing synchronous systems is introduced.
 These descriptions can be used for simulation
and automatic design of the system described, in
addition to communicating system specifications.
.A
Parnas, D. L.
.I 1485
.T
The Structure of Programming Languages
.W
In this paper the major components of every
programming language are identified as: (1) the
elementary program statement, (2) mechanisms for linking
elementary statements together, (3) the means
by which a program can obtain data inputs.  Several
alternative forms of each of these components are
also described, compared and evaluated.  Many examples,
frequently from list processing languages, illustrate
the forms described.  The advantages, disadvantages and
factors influencing the choice of a form of component
for a language are discussed, and the paper concludes
with the suggestion that programming languages
evolve toward one which will permit all the most convenient
ways of structuring programs, organizing
systems and referencing data.
.A
Raphael, B.
.I 1486
.T
A Reprogramming Machine
.W
In this paper a description is given of a model
programming system which is directed by a programming
language and has a library for storing the user's items.
 Rules are given for transforming programs written
in the language and for rearranging the items in the
library so that they share their common parts.
Some speculations are made about how the mechanical
detection of common parts or patterns of library
items could help a user to solve his problems, and about
the relationships between the behavior of the
reprogramming machine and human intelligent behavior.
.A
Burge, W. H.
.I 1487
.T
ELIZA-A Computer Program For the Study ofNatural
Language Communication Between Man And Machine
.W
ELIZA is a program operating within the MAC
time-sharing system at MIT which makes certain
kinds of natural language conversation between man and
computer possible.  Input sentences are analyzed
on the basis of decomposition rules which are triggered
by key words appearing in the input text.  Responses
are generated by reassembly rules associated with selected
decomposition rules.  the fundamental technical
problems with which ELIZA is concerned are: (1)the
identification of key words, (2) the discovery of
minimal context, (3) the choice of appropriate transformations,
(4) generation of responses in the absence
of key words, and (5) the provision of an editing capability
for ELIZA "scripts".  A discussion of some
psychological issues relevant to the ELIZA approach as
well as of future developments concludes the paper.
.A
Weizenbaum, J.
.I 1488
.T
Programming Decision Tables in FORTRAN, COBOL or ALGOL
.W
A simple broad-based approach for programming
decision tables in FORTRAN or COBOL is developed
and presented.  With inputs in standard form, as defined
in the paper, the programming of any decision
table can be done with one or two FORTRAN statements,
or with two COBOL statements, if the COMPUTE verb
is available in the COBOL processor.  It is  shown
that the method is applicable even when there are
more than two mutually exclusive states of one, two or
more table conditions.  It is further shown that
multi-state conditions in decision tables can often
simplify the programming.  The method outlined has
the further advantage that all possible combinations
of conditions are considered.  It is shown that
the suggested procedure is easily implemented in ALGOL.
.A
Veinott, C. G.
.I 1489
.T
Data, Documentation and Decision Tables
.W
In business data processing systems, it is
necessary to be able to define and document data,
files, programs and decision rules in a way that adequately
represents both (1) their changing information
content, and (2) their continuous interaction.  Tabular
description makes this possible, being notably
objective, through and economical in cost and time when
systems must be analyzed and programs prepared
or modified.  To show how quickly tabular techniques
make an unfamiliar system manageable, a detailed
example and a self-test are provided.
.A
Fisher, D. L.
.I 1490
.T
One Inch Perforated Paper Tape for Information
Interchange (Proposed American Standard)
.I 1491
.T
EULER: A Generalization ALGOL, and its Formal Definition: Part I*
.W
A method for defining programming languages is
developed which introduces a rigorous relationship
between structure and meaning.  The structure of a
language is defined by a phrase structure syntax,
the meaning in terms of the effects which the execution
of a sequence of interpretation rules exerts
upon a fixed set of variables, called the Environment.
 There exists a one-to-one correspondence between
syntactic rules and interpretation rules is determined by
the sequence of corresponding syntactic reductions
which constitute a parse.  The individual interpretation
rules are explained in terms of an elementary
an d obvious algorithmic notation.  A constructive
method for evaluating a text is provided, and for
certain decidable classes of languages their unambiguity
is proved.  As an example, a generalization
of ALGOL is described in full detail to demonstrate that
concepts like block-structure, procedures, parameters,
etc. can be defined adequately and precisely by this method.
.A
Wirth, N.
Weber, H.
.I 1492
.T
Serrev (Algorithm 273 [C1])
.A
Thacher Jr., H. C.
.I 1493
.T
Generation of Hilbert Derived Test Matrix (Algorithm 274 [F1])
.A
Boothroyd, J.
.I 1494
.T
Complete Elliptic Integral of the Second Kind (Algorithm 56 [S21])
.A
Larssen, G. M.
.I 1495
.T
Solution of Transcendental Equations by Series Reversion
.W
An algorithm is developed for expressing the
solution Y, of the equation F(Y) = G(X) as a power
series in (X - X0) when f and g are given as power series,and
the root Y0, is known at Y=X0.  The algorithm
is illustrated for the equation Y^Y = X, i.e., (1+y)*ln(1+y) = ln(1+x).
.A
Thacher Jr., H. C.
.I 1496
.T
A Formal Semantics for Computer Languages
and its Application In a Compiler-Compiler
.W
A semantic meta-language has been developed
for representing the meanings of statements in
a large class of computer languages.  This meta-language
has been the basis for construction of an efficient,
functioning compiler-compiler.  An informal discussion
of the meta-language based on the example of a
complete translator for a small language is presented.
.A
Feldman, J. A.
.I 1497
.T
On the Normalization Requirement of
Divisor in Divide- and- Correct Methods
.W
This paper presents an analysis on the normalization
requirement of the divisor in a divide-and-correct
method.  This analysis is made subject to the condition
that not more than one correction is required
to obtain the true quotient character, from the trial
estimate got from the division of a two-precision
segment of every partial remainder by a suitably rounded
single-precision divisor.  (This segmented division
is denoted here as a (2, 1) precision basic division.)
 It is found that the normalization requirement
could be narrowed down to a smaller range of divisors,
provided the magnitude of the character next to
the leading character of the divisor is known.  If,
however, the normalization is to be eliminated one
has to choose proper higher precision segments of operands
for the basic division.  Also considered is
the possibility of eliminating the normalization by an
increase on the number of corrections on the quotient
estimate got from a (2, 1) precision basic division.
 It is shown that such a scheme is economical only
for small radices.
.A
Krishnamurthy, E. V.
Nandi, S. K.
.I 1498
.T
The ALCOR Illinois 7090/7094 Post Mortem Dump
.W
A dump technique for programs written in ALGOL
60 is described.  This technique provides an
intelligible analysis of an unsuccessful computation
process in terms of the original source program.
.A
Bayer, R.
Gries, D.
Paul, M.
Wiehle, H. R.
.I 1499
.T
Chebyschev Curve-Fit (revised) (Algorithm 318 [E2])
.A
Boothroyd, J.
.I 1500
.T
Chebyschev Curve-Fit (Algorithm 91 [E2])
.A
Boothroyd, J.
.I 1501
.T
Eigenvectors of a 2n x 2n Matrix
.W
It has been known that the eigenvalues of a
certain 2n x 2n matrix can be obtained by use of
two smaller matrices of order n which can be easily
constructed.  An algorithm is given to obtain the
eigenvectors of the 2n x 2n matrix by use of
the eigenvectors of the smaller matrices.
.A
Charmonman, S.
.I 1502
.T
An Online Editor
.W
An online, interactive system for test editing
is described in detail, with remarks on the
theoretical and experimental justification for its form.
 Emphasis throughout the system is on providing
maximum convenience and power for the user.  Notable
features are its ability to handle any piece of
text, the content-searching facility, and the character-by-character
editing operations.  The editor
can be programmed to a limited extent.
.A
Deutsch, L. P.
Lampson, B. W.
.I 1503
.T
A SIMSCRIPT-FORTRAN Case Study
.W
Two programs for a vehicle dispatching model,
one written in 7040 SIMSCRIPT and the other in
7040 FORTRAN IV are compared. The comparison is made
in terms of basic program design decisions, storage
requirements, computer time used, and the ease of making
changes.  In the SIMSCRIPT program, the primary
design considerations center around the choice of model
variables, model changing events, and model testing.
 In the FORTRAN program, basic design problems relate
to the representation of the passage of time, the
allocation of storage, and the organization of input
data.  The comparison of these differently designed
programs shows that the SIMSCRIPT program uses more computer
storage and more computer time, but requires
fewer program changes to introduce model revisions.
.A
Weinert, A. E.
.I 1504
.T
Algorithms for Finding a Fundamental Set
of Cycles for an Undirected Linear Graph
.W
Given the adjacency matrix of the graph, the algorithm
presented in this paper finds a spanning
tree and then constructs the set of fundamental cycles.
 Our algorithm is slower than an algorithm presented
by Welch by a ratio of N/3 (N is the number of nodes)
but requires less storage.  For graphs with a large
number of nodes and edges, when storage is limited our
algorithm is superior to Welch's; however, when
the graphs are small, or machine storage is very large,
Welch's algorithm is superior.  Timing estimates
and storage requirements for both methods are presented.
.A
Gotlieb, C. C.
Corneil, D. G.
.I 1505
.T
A System Organization for Resource Allocation
.W
This paper introduces a system for resource management
using the concepts of "process," facility,"
and "event."  Except for the processor no attempt has
been made to give serious suggestions for the policy
to be followed for resource allocation.  However, a basic
framework is provided in which a system analyst
can express solutions to resource management problems.
 The paper is divided into a tutorial presentation,
a description of the system primitives, and a small collection
of examples of the use of the primitives.
.A
Dahm, D. M.
Gerbstadt, F. H.
Pacelli, M. M.
.I 1506
.T
The LACONIQ Monitor: Time Sharing for Online Dialogues
.W
The LACONIQ (Laboratory Computer Online Inquiry)
Monitor was developed primarily to support
non-numerical applications such as retrieval from very
large files by means of a "dialogue" between a
system user and a retrieval application.  The monitor
was designed so that it could work with a small
computer (an IBM System 360/30).  Therefore techniques
for resource allocation were important.  For this
reason the use of core storage, computational facilities,
and input-output were all scheduled.  An unusual
feature of the system is that it is event-driven rather
than clock-driven.  The program segments called
into execution by the remote CRT consoles are invariably
run to completion rather than "rolled-out" to
be brought back at a later time.
.A
Drew, D. L.
.I 1507
.T
A Multiprogramming Environment for Online Data Acquis ition and Analysis
.W
An experimental system for acquis ition and analysis
of large bodies of data derived from scientific
experiments is described.  Its architecture and implementation
is largely based on certain objectives
and characteristics of a general data analysis scheme.
 Early applications have been oriented towards
the investigation of data obtained in biological research.
 Some of the problems encountered by the chosen
approach are discussed.
.A
Lockemann, P. C.
Knutsen, W. D.
.I 1508
.T
Magnetic Tape Labels for Information Interchange (Proposed USA Standard)
.I 1509
.T
Recorded Magnetic Tape for Information Interchange
(200 CPI, NRZI) (Proposed USA Standard)
.I 1510
.T
Finding a Solution of N Functional Equations
in N Unknown (Algorithm 314 [C5])
.A
Dulley, D.B.
Pitteway, L. V.
.I 1511
.T
The Damped Taylor's Series Method for Minimizing
a Sum of Squares and for Solving Systems of
Nonlinear Equations
.A
Spath, H.
.I 1512
.T
Solution of Simultaneous Non-Linear Equations (Algorithm 316[C5])
.A
Brown, K. M.
.I 1513
.T
PERMUTATION (Algorithm 317 [G6])
.A
Robinson, C. L.
.I 1514
.T
On the Expected Gain From Adjust ing Matched Term Retrieval Systems
.W
A file adjustment procedure based on maximizing
the Bayes expected gain proposed for matched
term retrieval systems.  The expected gain and its probability
distribution are derived as a function
of: (1) the prior proportion of omitted terms, and (2) the
coefficient of separation between two distributions
corresponding to values of an adjustment statistic.  An
example evaluates the gain parameters for a typical
information retrieval system.
.A
Shumway, R. H.
.I 1515
.T
A Computer System for Inference Execution and Data Retrieval
.W
This paper presents a RAND project concerned
with the use of computers as assistants in the
logical analysis of large collections of factual data.
 A system called Relational Data File was developed
for this purpose.  The Relational Data File is briefly
detailed and problems arising from its implementation
are discussed.
.A
Levien, R. E.
.I 1516
.T
Automatic Data Compression
.W
The "information explosion" noted in recent
years makes it essential that storage requirements
for all information be kept to a minimum.  A fully automatic
and rapid three-part compressor which can
be used with "any" body of information to greatly reduce
slow external storage requirements and to increase
the rate of information transmission through a computer
is described in this paper.  The system will
also automatically decode the compressed information
on an item-by-item basis when it is required.  The
three component compressors, which can be used separately
to accomplish their specific tasks, are discussed:
NUPAK for the automatic compression of numerical data, ANPAK
for the automatic compression of "any" information,
and IOPAK for further compression of information to be stored on tape or cards.
.A
Marron, B. A.
DeMaine, P. A. D.
.I 1517
.T
Methods for Analyzing Data from Computer Simulation Experiments
.W
This paper addresses itself to the problem of
analyzing data generated by computer simulations
of economic systems.  We first turn to a hypothetical firm,
whose operation is represented by  single-channel,
multistation queueing model.  The firm seeks to maximize
total expected profit for the coming period
by selecting one of five operating plans, where each
plan incorporates a certain marketing strategy,
an allocation of productive inputs, and a total cost.
 The results of the simulated activity under each
plan are subjected to an F-test, two multiple comparison
methods, and a multiple ranking method.  We
illustrate, compare, and evaluate these techniques.
 The paper adopts the position that the particular
technique of analysis (possibly not any one of the above)
chosen by the experimenter should be an expression
of his experimental objective: The F-test tests the homogeneity
of the plans; multiple comparison methods
quantify their differences; and multiple ranking methods
directly identify the one best plan or best
plans.
.A
Naylor, T. H.
Wertz, K.
Wonnacott, T. H.
.I 1518
.T
An Experimental Model of System/360
.W
The problem of predicting the performance of
modern computer systems is formidable.  One general
technique which can ease this problem is macroscopic simulation.
 This paper reports on the applicability
of that technique to System/360.  The paper describes
an experimental model of System/360-its hardware,
software, and its environment.  The measures of system performance
produced by the model consist of statistics
relating to turnaround time, throughput, hardware utilization,
software utilization, and queueing processes.
 The model is mechanized in SIMSCRIPT and consists of
some 1750 statements.  An auxiliary programs, the
Job Generator, creates automatically the properties
of System/360 jobs that get simulated.
.A
Katz, J. H.
.I 1519
.T
GEORGE 3-A General Purpose Time Sharing and Operating System
.W
An Operating System is described which will
run on a wide variety of configurations of the
I.C.T. 1900, and can handle a large number of online console
users while at the same time running several
off line (background) jobs.  The system is not oriented
towards either mode and can be either a batch
processing system (such as the ATLAS Supervisor, IBSYS,
or GECOS), or a multiaccess system (resembling,
to the user, CTSS or MULTICS), or both simultaneously,
depending on the installation, which can adjust
the Schedulers.  Both online users and off line jobs use
a common Command Language.  The system includes
a Multilevel device-independent File Store.
.A
Oestreicher, M. D.
Bailey, M. J.
Strauss, J. I.
.I 1520
.T
Absolute Value and Square Root of a Complex Number (Algorithm 312 [A2])
.A
Friedland, P.
.I 1521
.T
Multi-Dimensional Partition Generator (Algorithm 313 [A1])
.A
Bratley, P.
McKay, J. K. S.
.I 1522
.T
Chebyschev Quadrature (Algorithm 279 [D1])
.A
Hillstrom, K.
.I 1523
.T
SHARER, a Time Sharing System for the CDC 6600
.W
A time sharing system embedded within the
standard batch processing system for the CDC 6600
is described.  The system is general purpose and file-based,
providing facilities for file input, manipulation,
editing, compilation, and conversational execution.
 It uses a simple scheme for system extension for
a machine with only one relocation and memory bound register.
 No attempt was made to use reentrant code,
or to simulate segmentation or paging.  Implementation
time was approximately six man-years, with the
majority of the code being written in FORTRAN.
.A
Harrison, M. C.
Schwartz, J. T.
.I 1524
.T
A Stopping Criterion for Polynomial Root Finding
.W
When searching for the root of a polynomial,
it is generally difficult to know just when to
accept a number as an adequate approximation to the root.
 In this paper an algorithm is presented which
allows one to terminate the iteration process on the
basis of calculated bounds for the roundoff error
which occurs in evaluating the polynomial.  This stopping
criterion has been tested on numerous examples
and has been found to serve as a satisfactory means
for accepting a complex number as a zero of a real
polynomial.
.A
Adams, D. A.
.I 1525
.T
On Computing The Fast Fourier Transform
.W
Cooley and Tukey have proposed a fast algorithm
for computing complex Fourier transform and
have shown major time savings in using it to compute
large transforms on a digital computer.  With n
a power of two, computing time for this algorithm is
proportional to n log2 n, a major improvement over
other methods with computing time proportional to n^2.
 In this paper, the fast Fourier transform algorithm
is briefly reviewed and fast difference equation methods
for accurately computing the needed trigonometric
function values are given.  The problem of computing
a large Fourier transform on a system with virtual
memory is considered, and a solution is proposed.  This
method has been used to compute complex Fourier
transforms of size n = 2^16 on a computer with 2^15
words of core storage; this exceeds by a factor of
eight the maximum radix two transform size with fixed
allocation of this amount of core storage.  The
method has also been used to compute large mixed radix
transforms.  A scaling plan for computing the
fast Fourier transform with fixed-point arithmetic is also given.
.A
Singleton, R. C.
.I 1526
.T
Multiprogramming under a Page on Demand Strategy
.W
A model of multiprogramming for a particular
computer system using a page on demand strategy
is developed.  Analysis of this model is used to predict
performance (measured by the average usage of
the CPU) when user programs are typical of those arising
from an interactive time sharing environment.
 The effect of several hardware modifications is also
analyzed.  A parameter, readily calculated from
the hardware characteristics and the program statistics,
is proposed for gauging the effect of multiprogramming.
.A
Smith, J. L.
.I 1527
.T
A Grammar Base Question Answering Procedure
.W
The subject of this paper is a procedure for
the automatic retrieval of certain segments of
stored information, either explicitly or implicitly represented,
through questions posed in natural language
sentences.  This procedure makes use of a sentence recognition
device for the class of grammars which
will correctly decide between the grammatical and ungrammatical
sentences of a natural language.  It
is possible to make use of a recognition device of this
sort for the following reason: Much data is fully
expressible as a set of sentences in a natural language,
a set which can be exhaustively and exclusively
generated by a grammar.  Based upon the rules of this grammar,
a sentence recognizer will evaluate sentences,
questions in the normal situation.  Since the recognition
function succeeds just in case the posed question
is drawn from the set of sentences expressing the data,
or, more correctly, is grammatical in terms of
the grammar for this set of sentences, sentence recognition
itself is a procedure for retrieving information.
 When the recognition function succeeds, its
value represents the requested information.
.A
Rosenbaum, P.
.I 1528
.T
Three Fonts of Computer Drawn Letters
.W
Detailed descriptions are given for three fonts
of letters.  Letter shapes are entirely described
by numbers.  The basic vectors are in a general form
so the fonts may be easily drawn on a variety of
computers and cathode-ray tubes.  The fonts include both
upper and lower case Roman letters, mathematical
signs, and upper and lower case Greek letters.  Design
of the fonts is described.  However, the principal
contribution of this paper concerns the fonts themselves.
.A
Mathews, M. V.
Lochbaum, C.
Moss, J. A.
.I 1529
.T
Decomposition Programming An Analysis of Matrix Substructure
.W
A petroleum blending problem was analyzed in order
to compare the primal and primal-dual decomposition
algorithms.  In the course of the analysis, a substructure
was discovered which has relevance to the
relative performance of the two algorithms and to their
absolute performance as compared with a standard
primal-Simplex solution without decomposition.
.A
Bell, E. J.
.I 1530
.T
The ML/I Macro Processor
.W
A general purpose macro processor called ML/I
is described.  ML/I has been implemented on the
PDP-7 and I.C.T. Atlas 2 computers and is intended as a
tool to allow users to extend any existing programming
language by incorporating new statements and other
syntactic forms of their own choosing and in their
own notation.  This allows a complete user-oriented
language to be built up with relative ease.
.A
Brown, P. J.
.I 1531
.T
The Remaining Trouble Spots in ALGOL 60
.W
This paper lists the ambiguities remaining
in the language ALGOL 60, which have been noticed
since the publication of the Revised ALGOL 60 Report in 1963.
.A
Knuth, D. E.
.I 1532
.T
The Hardware-Software Complementarity
.A
Oettinger, A. G.
.I 1533
.T
A Marovian Model of the University of Michigan Executive System
.W
A mathematical model of a computer's executive
system is postulated and its parameters estimated
with the aid of extensive data on the system's operation.
 Although simplifying assumptions are made,
the results predicted by the model agree reasonable well
with actual results.  The model is used to study
the effects of changes in the executive system and
in one of its compilers.  Further applications of
the model are discussed.
.A
Foley, J. D.
.I 1534
.T
DAD, The C.S.I.R.O. Operating System
.W
The design and implementation of the C.S.I.R.O.
operating system, DAD, is described in detail.
 This system is designed for the Control Data 3600 using
a large drum backing store and is intended to
allow the integration of a remote console (display) subsystem
into a conventional job stack environment.
 The use of the drums, the buffering of input and output
on slow peripherals, and the execution of normal
job stack work are described.  The display subsystem
is described only as it integrates into the rest
of the system.  The techniques found useful in the development
of DAD are given, and an assessment is
made of the validity of various design decisions.  Performance
figures based on several months of operation
are tabulated.
.A
Austin, B. J.
Holden, T. S.
Hudson, R. H.
.I 1535
.T
A Comment on Index Register Allocation
.W
A technique is presented to reduce the enumeration
required by a known procedure for optimal
index register allocation in straight-line programs.
 This technique is based on the construction of
a link diagram, which shows at any step the future occurrences
of indexes which must be loaded into index
registers.  This diagram determines in advance the required
register configuration at certain steps of
the program, so that the program is subdivided into separate
portions to which the allocation procedure
may be applied independently.
.A
Luccio, F.
.I 1536
.T
Dynamic Computation of Derivatives
.W
It is shown how Wengert's procedure for computation
of derivatives can be implemented conveniently
by use of compiler-generated complex addition, subtraction,
and linkage to complex arithmetic subroutines.
 Evaluation of a function and derivative proceed in
parallel, as in Wengert's procedure, but with the
"imaginary" parts of variables declared complex bearing
the values of the derivatives of the real parts.
 This technique provides a simple way to compute the
derivatives of a function, without the need for
deriving and programming the evaluation of
explicit formulas for the derivatives.
.A
Lesk, A. M.
.I 1537
.T
Prime Number Generator 1 (Algorithm 310 [A1])
.A
Chartres, B. A.
.I 1538
.T
Prime Number Generator 2 (Algorithm 311 [A1])
.A
Chartres, B. A.
.I 1539
.T
Prime Number Generator 1; Prime Number Generator
2 (Algorithm 35[A1]; Algorithm 310[A1]; Algorithm
311[A1])
.A
Chartres, B. A.
.I 1540
.T
An Algorithm for Class Scheduling With Section Preference
.W
An algorithm for assignment of students to classes
in a fixed time schedule that allows students
to give a preference for sections within courses is given.
 If consistent with the objective of balanced
sections, these preferences will be honored.  The algorithm
is more stochastic than Monte Carlo in nature.
 Results are given that compare it to a nonpreference assignment algorithm.
.A
Busam, V. A.
.I 1541
.T
A Language for Modeling and Simulating Dynamic Systems
.W
The general objective of this language is
to facilitate both the modeling and experimental
aspects of simulation studies.  The ability to represent
systems containing highly interactive processes
is an essential feature.  The nature of the language,
and the role of the process concept, is presented
by means of an extended example.
.A
Parente, R. J.
Krasnow, H. S.
.I 1542
.T
A Microprogrammed Implementation of EULER on IBM System/360 Model 30
.W
An experimental processing system for the algorithmic
language EULER has been implemented in
microprogramming on an IBM System/360 Model 30 using a
second Read-Only Storage unit.  The system consists
of a microprogrammed compiler and a microprogrammed
String Language Interpreter, and of an I/O control
program written in 360 machine language.  The system is described
and results are given in terms of microprogram
and main storage space required and compiler and interpreter
performance obtained.  The role of microprogramming
is stressed, which opens a new dimension in the processing
of interpretive code.  The structure and content
of a higher level language can be matched by an appropriate
interpretive language which can be executed
efficiently by microprograms on existing computer hardware.
.A
Weber, H.
.I 1543
.T
Computer Formulation of the Equations of Motion Using Tensor Notation
.W
A means is described for extending the area
of application of digital computers beyond the
numerical data processing stage and reducing the need for
human participation in the formulation of certain
types of computer problems.  By the use of tensor calculus
and a computer language designed to facilitate
symbolic mathematical computation, a method has been
devised whereby a digital computer can be used to
do non-numeric work, that is, symbolic algebraic manipulation
and differentiation. To illustrate the
techniques involved, a digital computer has been used
to derive the equations of motion of a point mass
in a general orthogonal curvilinear coordinate system.
 Since this operation involves a formulation in
terms of first- and second-order differential coefficients,
it provides a good demonstration of a computer's
capability to do non-numeric work and to assist in the
formulation process which normally precedes the
numerical data processing stage.  Moreover, this particular
problem serves to illustrate the advantages
of the mathematical techniques employed.  With the program
prepared for this purpose the computer will
derive the equations of motion in any coordinate system
requested by the user.   Results are presented
for the following coordinate systems: cylindrical
polar, spherical polar, and prolate spheroidal.
.A
Howard, J. C.
.I 1544
.T
Tele-CUPL: A Telephone Time Sharing System
.W
A general purpose, remote access, computing system
is described, that employs twelve-key keyboard
telephones as terminals.  Audio output is provided directly
to the telephone terminals, but the system
will normally be used in conjunction with remotely located
high speed printing devices.  The system is
a compatible extension of an existing batch processing
system.  A significant element of the system is
a scheme for transmitting alphanumeric information by single
strokes on a numeric keyboard.  The programmed
scanner uses context to eliminate the ambiguity in transmission.
.A
Conway, R. W.
Morgan, H. L.
.I 1545
.T
Legal Safeguards to Insure Privacy in a Computer Society
.A
Westin, A. F.
.I 1546
.T
Toward Standards for Handwritten Zero and Oh
.A
Bemer, R. W.
.I 1547
.T
Gamma Function with Arbitrary Precision (Algorithm 309 [S14])
.A
Filho, A. M.S.
Schwachheim, G.
.I 1548
.T
Parsing of Decision Tables
.W
Reduction in the size of decision tables can be
accomplished by several techniques.  The techniques
considered in this paper are on the parsing of decision
tables with regard to horizontal and vertical
data structures, job identity, hardware and job priorities,
and context relationships.  Such parsing
rests upon some conventions for the linkage of decision tables.
.A
Chapin, N.
.I 1549
.T
An Efficient Machine-Independent Procedure for
Garbage Collection in Various List Structures
.W
A method for returning registers to the free
list is an essential part of any list processing
system.  In this paper, past solutions of the recovery
problem are reviewed and compared.  A new algorithm
is presented which offers significant advantages of speed
and storage utilization.  The routine for implementing
this algorithm can be written in the list language with
which it is to be used, thus insuring a degree
of machine independence.  Finally, the application of the
algorithm to a number of different list structures
appearing in the literature is indicated.
.A
Schorr, H.
Waite, W. M.
.I 1550
.T
A Comparison of Batch Processing and Instant Turnaround
.W
A study of the programming efforts of students
in an introductory programming course is presented
and the effects of having instant turnaround (a few minutes)
as opposed to conventional batch processing
with turnaround times of a few hours are examined.  Among
the items compared are the number of computer
runs per trip to the computation center, program preparation
time, keypunching time, debugging time,
number of runs, and elapsed time from the first run
to the last run on each problem.  Even though the
results are influenced by the fact that "bonus points"
were given for completion of a programming problem
in less than a specified number of runs, there
is evidence to support "Instant" over "Batch".
.A
Smith, L. B.
.I 1551
.T
On Compiling Algorithms for Arithmetic Expressions
.W
This paper deals with algorithms concerning arithmetic
expressions used in a FORTRAN IV compiler
for a HITAC-5020 computer having n accumulators.  The
algorithms generate an object code which minimizes
the frequency of storing and recovering the partial results
of the arithmetic expressions in cases where
there are several accumulators.
.A
Nakata, I.
.I 1552
.T
The AED Free Storage Package
.W
The most fundamental underlying problem in sophisticated
software systems involving elaborate,
changing data structure is dynamic storage allocation
for flexible problem modeling.  The Free Storage
Package of the AED-1 Compiler Systems allows blocks
of available storage to be obtained and returned
for reuse.  The total available space is partitioned
into a hierarchy of free storage zones, each of
which has its own characteristics.  Blocks may be of
any size, and special provisions allow efficient
handling of selected sizes, control of shattering and
garbage collection, and sharing of physical space
between zones.  The routines of the package perform
high level functions automatically, but also allow
access and control of fine internal details as well.
.A
Ross, D. T.
.I 1553
.T
Contextual Understanding by Computers
.W
A further development of a computer program
(ELIZA) capable of conversing in natural language
is discussed.  The importance of context to both human
and machine understanding is stressed.  It is
argued that the adequacy of the level of understanding
achieved in a particular conversation depends
on the purpose of that conversation, and that absolute
understanding on the part of either humans or
machines is impossible.
.A
Weizenbaum, J.
.I 1554
.T
A Computer Technique for Displaying n-Dimensional Hyperobjects
.W
A digital computer and automatic plotter have
been used to generate three-dimensional stereoscopic
movies of the three-dimensional parallel and perspective
projections of four-dimensional hyperobjects
rotating in four-dimensional space.  The observed projections
and their motions were a direct extension
of three-dimensional experience, but no profound "feeling"
or insight into the fourth spatial dimension
was obtained.  The technique can be generalized to n-dimensions
and applied to any n-dimensional hyperobject
or hypersurface.
.A
Noll, A. M.
.I 1555
.T
Symmetric Polynomials (Algorithm 305 [C1])
.A
Bratley, P.
McKay, J. K. S.
.I 1556
.T
Permutations with Repetitions (Algorithm 306 [G6])
.A
Bratley, P.
.I 1557
.T
Symmetric Group Characters (Algorithm 307 [A1])
.A
McKay, J. K. S.
.I 1558
.T
Generation of Permutations in Pseudo-Lexicographic
Order (Algorithm  [G6])
.A
Ord-Smith, R. J.
.I 1559
.T
Permutation Generator; Permutation in Lexicographical
Order; Permute; Generation of Permutations
in Lexicographical Order (Algorithm 87[G6]; Algorithm
102[G6]; Algorithm 130[G6]; Algorithm 202[G6])
.A
Ord-Smith, R. J.
.I 1560
.T
Transport; Transportation Problem (Algorithm 258[H]; Algorithm 293[H])
.A
Sims, L. S.
.I 1561
.T
The Mutual Primal-Dual Method (Algorithm 285 [H])
.A
Spath, H.
.I 1562
.T
Airy Function (Algorithm 301 [S20])
.A
Pitteway, M. L. V.
.I 1563
.T
A Method for Finding Hamilton Paths and Knight's Tours
.W
The use of Warnsdorff's rule for finding a
knight's tour is generalized and applied to the
problem of finding a Hamilton path in a graph.  A graph-theoretic
justification for the method is given.
.A
Pohl, I.
.I 1564
.T
Description of Basic Algorithm in DETAB/65 Preprocessor
.W
The basic algorithm for the conversion of decision
tables into COBOL code is contained in the
generator portion of the DETAB/65 preprocessor.  The
generator analyzes a decision table and produces
simple COBOL conditional statements.  Core storage is
saved by using queueing techniques and extensive
indexing and also by outputting the code as it is generated,
a line at a time.  The only optimization
attempted is the elimination of obviously unnecessary
tests on certain conditions in the decision table.
 Since the preprocessor and this language associated with
it were developed for COBOL users, the preprocessor
was written in a modular form in required COBOL-61.
.A
Callahan, M. D.
Chapman, A. E.
.I 1565
.T
A Language-Independent Macro Processor
.W
A macro processor is described which can be
used with almost any source language.  It provides
all features normally associated with a macro facility,
plus the ability to make arbitrary transformations
of the argument strings.  The program is used at the
Basser Computing Department, University of Sydney,
Sydney, Australia, to process text for eight different compilers.
.A
Waite, W. M.
.I 1566
.T
Optimal Starting Values for Newton-Raphson Calculation of SQRT(x)
.W
The problem of obtaining starting values for
the Newton-Raphson calculation of SQRT(x) on a
digital computer is considered.  It is shown that the
conventionally used best uniform approximations
to SQRT(x) do not provide optimal starting values.
The problem of obtaining optimal starting values.
 The problem of obtaining optimal starting values is
stated, and several basic results are proved.  A
table of optimal polynomial starting values is given.
.A
Moursund, D. G.
.I 1567
.T
On the Representation of Symmetric Polynomials
.W
Relations are given between certain symmetric
polynomials in the light of the theory of the
symmetric group.  Such an approach unifies earlier work
and lends insight to previously published work
by Aaron Booker.  A generalization of Graeffe's root-squaring
technique for the determination of the
roots of a polynomial is suggested.
.A
McKay, J. K. S.
.I 1568
.T
Plotting a Function of Three Independent Variables
.W
A method is developed for constructing an approximate
plot of a function of three independent
variables.  The plot is similar to a conventional contour
map except that there are three scales to represent
the independent variables.  Scale values of the three
independent variables are added vectorially, and
the value of the function is then read from
the values associated with nearby contours.
.A
Stineman, R. W.
.I 1569
.T
Implementing Phrase-Structure Productions in PL/I
.W
A method is described for implementing the productions
of a context-free phrase structure grammar
in a PL/I procedure whose structure and statements parallel
the structure and notation of the grammar.
.A
Irwin, L.
.I 1570
.T
String Processing Techniques
.W
The internal organization of string processing
systems is discussed.  Six techniques for data
structures are presented and evaluated on the basis of:
(1) creation of strings; (2) examination of strings;
and (3) alteration of strings.  Speed of operation, storage
requirements, effect on paging, and programmer
convenience are also considered.  One of the techniques,
single-word linked blocks, is used in an example
demonstrating an implementation of a SNOBOL string
processing language on an IBM System/360.
.A
Madnick, S. E.
.I 1571
.T
A User-Oriented Time-Shared Online System
.W
An existing system and planned additions within
the Data Processing Laboratory of the Brain
Research Institute at UCLA is described.  The system
represents an attempt to provide research workers
of the Institute with the ability to interact directly
with a highly sophisticated digital computing
complex in the most direct and simple fashion possible.
 It is anticipated that, with the accumulation
of experience using the present system, significant advances
will be possible in the system design through
determination of interface parameters between the
biological scientist and the digital computer.
.A
Betyar, L.
.I 1572
.T
The Simulation of Time sharing Systems
.W
The development of new large scale time-sharing
systems has raised a number of problems for
computation center management.  Not only is it necessary
to develop an appropriate hardware configuration
for these systems, but appropriate software adjustments
must be made.  Unfortunately, these systems often
do not respond to changes in the manner that intuition
would suggest, and there are few guides to assist
in the analysis of performance characteristics.  The
development of a comprehensive simulation model
to assist in the investigation of these questions is
described in this paper.  The resulting model has
a general purpose design and can be used to study a
variety of time-sharing systems.  It can also be
used to assist in the design and development of new time-sharing
algorithms or techniques.  For the sake
of efficiency and greater applicability, the model was
implemented in a limited FORTRAN subset that is
compatible with most FORTRAN IV compilers. The use of
the simulation is demonstrated by a study of the
IBM 360/67 time-sharing system.
.A
Nielsen, N. R.
.I 1573
.T
An Adaptive Quadrature Procedure with
Random Panel Sizes (Algorithm [D1])
.A
Gallaher, L. J.
.I 1574
.T
Normal Curve Integral (Algorithm 304 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1575
.T
Incomplete Beta Ratio (Algorithm 179 [S14])
.A
Pike, M. C.
Hill, I. D.
.I 1576
.T
Eigenvalues of a Real Symmetric Matrix
by the QR Method (Algorithm 253 [F2])
.A
Welsch, J. H.
.I 1577
.T
Eigenvalues and Eigenvectors of a Real Symmetric
Matrix by the QR Method (Algorithm 254 [F2])
.A
Welsch, J. H.
.I 1578
.T
Generalized Least Squares Fit By Orthogonal
Polynomials (Algorithm 296 [E2])
.A
Makinson, G. J.
.I 1579
.T
Real Error Function, ERF(x) (Algorithm 123 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1580
.T
Error Function-Large X (Algorithm 180 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1581
.T
Complementary Error Function-Large X (Algorithm 181 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1582
.T
GAUSS (Algorithm 209 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1583
.T
Normal Distribution Function (Algorithm 226 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1584
.T
Procedure for the Normal Distribution Functions (Algorithm 272 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1585
.T
Normal Curve Integral (Algorithm 304 [S15])
.A
Hill, I. D.
Joyce, S. A.
.I 1586
.T
A Generalized Bairstow Algorithm
.W
The Bairstow algorithm is generalized to the
case of a polynomial which is itself a linear
combination of polynomials satisfying a three-term recursion.
 Convergence properties of the method are
derived.
.A
Golub, G. H.
Robertson, T. N.
.I 1587
.T
Storage Allocation in a Certain Iterative Process
.W
A method of core storage allocation in a certain
iterative process is described and estimates
of the machine time required are given.  The method is
applicable to iterative processes in which input
data items once chosen are never again needed.  In this
method the input data is continuously relocated
and the space made available apportioned to the output
tables when an overflow occurs.  Some important
special cases are considered in which considerable simplification occurs.
.A
Abramowich, J.
.I 1588
.T
PL/I List Processing
.W
The concepts of list processing have been introduced
into the PL/I language.  With these new
facilities, it is possible to write PL/I procedures that
operate on simple and complex data list organizations.
 Most list-processing languages have suffered from their
inability to deal directly with complex data
structures and/or from their inability to perform the
complete range of programming language operations
upon the data list structures.  These two problems have
been eliminated in the list-processing facilities
of PL/I.  The basic concepts of list processing and
the philosophy of the PL/I language extensions are
discussed.  In addition, several detailed list-processing examples are provided.
.A
Lawson Jr., H. W.
.I 1589
.T
DIALOG: A Conversational Programming System with a Graphical Orientation
.W
DIALOG is an algebraic language for online
use with a graphical input-output console device.
 It is a computational aid for the casual user, which
provides basic facilities for graphical and numeric
input and display, online and off line program preparation
and storage, and hard copy presentation of
results.  Use of the system requires a minimum of experience
or instruction, since the growth of an overlaying
system control language has been prevented, and there
are no processor-oriented statements, like variable
type or dimension declarations.  Moreover, in the online
situation the processor interacts with the graphical
keyboard on a character-by-character basis so as to
restrict the programmer's choice of input symbols
to those which are syntactically correct. DIALOG has been
in daily operation at the IIT Research Institute
since February, 1966.
.A
Cameron, S. H.
Ewing, D.
Liveright, M.
.I 1590
.T
Pitch Period Determination of Speech Sounds
.W
A computer procedure which determines pitch
periods by the recognition of the peak structure
of the speech waveform is described.  Speech sounds were
sampled by a microphone and an analog-to-digital
converter attached to an interconnected IBM 7090-PDP-1
system.  These utterances were recorded at the
normal noise level of the computer room but were not
band-compressed or phase-distorted in any manner.
 A sequence of operations defined on the speech wave selects
a list of points along the waveform as candidates
for pitch markers.  These markers are validated by
an error detection and correction procedure.About
95 percent of the pitch periods were recognized correctly
within 1 to 2 times real-time on the IBM 7090.
.A
Reddy, D. R.
.I 1591
.T
A Model for a Multifunctional Teaching System
.W
A teaching system model that was incorporated
into an operating system of a large computer
is described.  The model transferred control to the
operating system to execute functions other than
teaching, and then recovered control in order to resume
teaching.  The teaching system (ABAC-II) was
written to run under the operating system (IBSYS) for
the IBM 7044 Graphic System.  Because the teaching
system automatically terminated and rescheduled itself,
a student studying a course presented at a cathode-ray
display terminal could switch readily between student
mode and programmer mode.  During the latter, the
full resources of the operating system (language processors,
compilers, library and user's programs)
were at his disposal.  He could for example, write, assemble,
debug, and execute at the terminal a program
written in any language processed by the operating system.
 A course could therefore include text material
interleaved with programming problems which the student
could solve without leaving the terminal.  Exercises
in simulation and gaming could also be provided.  The
implications of a teaching system with this degree
of flexibility for industrial and executive training
as well as academic education are discussed.  In
addition, the advantages of this type of system for computer
programming and operation are also considered.
.A
Engvold, K. J.
Hughes, J. L.
.I 1592
.T
String Similarity and Misspellings
.W
The problem of programming a computer to determine
whether or not a string of characters is
a misspelling of a given word was considered.  A numberof
algorithms were evaluated-some proposed by
other writers, some by the author.  These techniques
were tested on a collection of misspellings made
by students at various grade levels.  While many of
the methods were clearly unsatisfactory, some gave
as few as 2.1 percent incorrect determinations.
.A
Alberga, C. N.
.I 1593
.T
A Simple Technique for Digital Division
.W
A simple and economical method for digital
division is described.  The method is suitable for
divisors whose leading character is either radix less
one or is unity with the next character equal to
zero; also the method is direct and needs only half the
number of arithmetic operations needed by a variant
of the Harvard iterative method, described by Gilman,
which is suitable for similar divisors.
.A
Nandi, S. K.
Krishnamurthy, E. V.
.I 1594
.T
An Algorithm for Generating Permutations
.W
An algorithm is described which under repeated
application generates all permutations of K
elements.  Only the previously generated permutation,
the constant K, and a temporary index are needed.
 Starting with a particular ordering of K elements (abcd),
repeated application of the algorithm will
generate K-1 additional permutations by K-1 successive
rotations.  From the initial circular ordering
of K objects, another circular ordering can be obtained
by rotating the K-1 lowest elements.  For each
new K-1 circular ordering, another K-2 can be obtained
by rotating the K-2 lowest elements.  By continuing
in this manner, applications of the algorithm will generate
all (K-1)! circular orderings, or since each
circular ordering yields K permutations the
algorithm generates all K! permutations.
.A
Langdon Jr., G. G.
.I 1595
.T
On the Computer Enumeration of Finite Topologies
.W
The problem of enumerating the number of topologies
which can be formed from a finite point
set is considered both theoretically and computationally.
 Certain fundamental results are established,
leading to an algorithm for enumerating finite topologies,
and computed results are given for n <= 7.
 An interesting side result of the computational work
was the unearthing of a theoretical error which
had been induced into the literature; the use of the computer
in combinatorics represents, chronologically,
an early application, and this side result underscores
its continuing usefulness in this area.
.A
Evans, J. W.
Harary, F.
Lynn, M. S.
.I 1596
.T
Airy Function (Algorithm 301 [S20])
.A
Bond, G.
Pitteway, M. L. V.
.I 1597
.T
Transpose Vector Stored Array (Algorithm 302 [K2])
.A
Boothroyd, J.
.I 1598
.T
Least Squares Fit By Orthogonal Polynomials (Algorithm 28 [E2])
.A
Makinson, G. J.
.I 1599
.T
Numerical Solution of the Polynomial Equation (Algorithm 300 [C2])
.A
Kohfeld, J. J.
.I 1600
.T
Chebyshev Quadrature (Algorithm 279 [D1])
.A
Hillstrom, K.
.I 1601
.T
Parallel Numerical Methods for the Solution of Equations
.W
Classical iterative procedures for the numerical
solution of equations provide at each stage
a single new approximation to the root in question.  A
technique is given for the development of numerical
procedures which provide, at each stage, several approximations
to a solution of an equation.  The s8everal
approximations obtained in any iteration are computationally
independent, making the methods of interest
in a parallel processing environment.  Convergence is
insured by extracting the "best information" at
each iteration.  Several families of numerical procedures
which use the technique of the procedures in
a parallel processing environment are developed and measurements
of these statistics are reported.  These
measurements are interpreted in a parallel processing
environment.  In such an environment the procedures
obtained are superior to standard algorithms.
.A
Shedler, G. S.
.I 1602
.T
POSE: A Language for Posing Problems to a Computer
.W
A language, POSE, is described which is a drastic
departure from the FORTRAN/ALGOL type, though
it does utilize FORTRAN formula and logic representations
(and actually contains FORTRAN VI as a subset).
 With the new language, the user need only describe
his problem in "equation-like" form. The method
of solution is automatically provided in conjunction
with the translation from equation form to computer
instruction. In this way the POSE language user can
solve difficult computational problems (like the
solution of differential equation) without requiring
a knowledge of numerical methods or the intricacies
of computer subroutine logic. Essentially all clerical
operations now required for FORTRAN programming
have been automated so that the POSE programmer
need not be concerned with these details.
.A
Schlesinger, S.
Sashkin, L.
.I 1603
.T
A Multiprogramming Monitor for Small Machines
.W
INT, a combination hardware/software monitor
designed to control a wide variety of real-time
input/output devices, is described.  The simple hardware
additions provide a uniform device to machine
interface for such elements as keyboards graphic input
devices, and interval timers.  The software relieves
the user program from the details of input/output timing,
buffering, and task scheduling and provides
parallel processing capability.  User programs communicate
with the monitor through a small set of meta-instruction
which consists mostly of machine-language subroutine calls.
.A
Hornbuckle, G. D.
.I 1604
.T
Further Analysis of a Computing Center Environment
.W
Empirical distributions of program lengths,
execution times, processing times, and loading
times of over 10,000 jobs serviced in a university computing
center environment are presented.  The data
are subdivided according to certain characteristics of users
and jobs to obtain selected empirical conditional
distributions of those time properties as well as statistical
measures of other interesting properties.
 The results are interpreted in terms of the properties of the system studied.
.A
Walter, E. S.
Wallace, V. L.
.I 1605
.T
An Experimental Comparison of Time Sharing and Batch Processing
.W
The effectiveness for program development
of the MIT Compatible Time-Sharing System (CTSS)
was compared with that of the IBM IBSYS batch-processing
system by means of a statistically designed
experiment.  An identical set of four programming problems
was assigned to each of a group of four programming
subjects.  Influences external to the systems, such as
the sequence of problem solution, and programmer
and problem characteristics, were specified as design
factors in the experiment.  Data was obtained for
six variables (e.g., programmer time, computer time,
elapsed time, etc.) which were considered to be
definitive of "system effectiveness," and analysis of
variance techniques were employed to estimate system
differences in these variables after differences due to
the design factors had been eliminated.  Statistical
analysis of the experimental results provided strong
evidence of important system differences, as well
as a critique of the experimental design itself
with implications for further experimentation.
.A
Schatzoff, M.
Tsao, R.
Wiig, R.
.I 1606
.T
Chi-Squared Integral (Algorithm 299 [S15])
.A
Hill, I. D.
Pike, M. C.
.I 1607
.T
Coulomb Wave Functions (Algorithm 300 [S22])
.A
Gunn, J. H.
.I 1608
.T
Numerical Integration of Function That Has a Pole
.W
It is common to need to integrate numerically
functions that diverge somewhere outside the
range of integration.  Even if the divergence occurs quite
far away, integration formulas like Simpson's,
that depend on fitting a polynomial, usually will be
inaccurate: near a pole they will be very bad.
A method is described that gives formulas that will integrate
functions of this kind accurately if the
orders and positions of the poles are known.  Explicit
formulas are given that are easy to use on an
automatic computer.  It is shown that they can be used
for some other singularities as well as poles.
 If the integral converges, integration can be carried
to the singularity.  The accuracy of the integration
with a pole of second order is discussed, and, as an example,
the new formula is compared with Simpson's.
 The new formulas are useful even far from the pole,
while near the pole their advantage is overwhelming.
.A
Eisner, E.
.I 1609
.T
Scheduling University Course Examinations by Computer
.W
A new approach to the problem of scheduling
course examinations is presented.  In principle,
an examination schedule which requires a minimum number
of examination periods and satisfies the constraint
that no student be required to take two examinations
simultaneously can be found in two steps.  First,
course which may have their examinations scheduled at
the same period are grouped together in all possible
ways.  Then a minimum number of these groups, such that
each course is included at least once, are selected.
 By removing multiple occurrences of courses and then scheduling
each group at a different period a minimal
schedule can be obtained.  Known algorithms for carrying
out these procedures are prohibitively expensive.
 Approximations to the ideal procedure outlined above are
given which yield nonminimal but feasible schedules
with a very small expenditure of time.  Results of experiments
using these techniques are given.  These
are encouraging and indicate that further experimentation would be worthwhile.
.A
Hall Jr., A. D.
Acton, F. S.
.I 1610
.T
A Method for the Solution of Transportation Problems with Tall Matrices
.W
A method is presented for the solution of the
transportation problem having a cost matrix with
few columns.  The computer implementation of this method
shows it to be very fast and efficient.  Application
are indicted for the personnel classification problem
as well as the classical transportation problem.
 An example is worked out in detail.
.A
Dwyer, P. S.
Galler, B. A.
.I 1611
.T
Scheduling Project Networks
.W
Some of the basic concepts and terminology
of project networking are developed.  The Critical
Path Algorithm incorporated in the C-E-I-R proprietary
scheduling system RAMPS (Resource Allocation and
Multi-Project Scheduling) is described.  The error detection
and network analysis features of the algorithm
are also described.
.A
Klein, M. M.
.I 1612
.T
Top-to-bottom Parsing Rehabilitated?
.W
This note is concerned with the efficiency
of the Top-to-Bottom parsing algorithm as used in
connection with programming language grammars.  It is
shown, for instance, that retracing of unprofitable
paths can often be eliminated by a suitable rearrangement
of the productions defining the grammar.  The
essential weakness of the method is in dealing with complicated
syntactic structures which are in practice
only sparsely occupied, e.g., arithmetic expressions.
.A
Brooker, R. A.
.I 1613
.T
One-Pass Compilation of Arithmetic Expressions for a Parallel Processor
.W
Under the assumption that a processor may have
a multiplicity of arithmetic units, a compiler
for such a processor should produce object code to take
advantage of possible parallelism of operation.
 Most of the presently known compilation techniques
are inadequate for such a processor because they
produce expression structures that must be evaluated serially.
 A technique is presented here for compiling
arithmetic expressions into structures that can be
evaluated with a high degree of parallelism.  The
algorithm is a variant of the so-called "top-down"
analysis technique, and requires only one pass of
the input text.
.A
Stone, H. S.
.I 1614
.T
A Proposal for Definitions in ALGOL
.W
An extension to ALGOL is proposed for adding
new data types and operators to the language.
 Definitions may occur in any block heading and terminate
with the block.  They are an integral part
of the program and are not fixed in the language.  Even
the behavior of existing operators may be redefined.
 The processing of text containing defined contexts features
a "replacement rule" that eliminates unnecessary
iterations and temporary storage.  Examples of definition sets
are given for real and complex matrices,
complex numbers, file processing, and list manipulation.
.A
Galler, B. A.
Perlis, A. J.
.I 1615
.T
An Algorithm for Generating Root Locus Diagrams
.W
A technique for using a digital computer to
draw both ordinary and time-lag root locus diagrams
is described.  Ordinary diagrams are drawn much faster
and more accurately than ever before.  Time-lag
diagrams, which had been impossible to obtain, are drawn
with the same speed and accuracy as ordinary
diagrams.
.A
Krall, A. M.
Fornaro, R.
.I 1616
.T
Tensor Calculations on Computer: Appendix
.W
In the main text of the paper [Comm. ACM 9,
12 (Dec. 196), 864], a FORMAC program was discussed
which is capable of calculating various quantities
of interest in tensor calculus.  This Appendix is
intended as an example of the program output.  Chrisoffel
symbols calculated for 12 basic orthogonal
coordinate systems are listed.
.A
Walton, J. J.
.I 1617
.T
Eigenvalues and Eigenvectors of the
Symmetric System (Algorithm 297 [F2])
.A
Boothroyd, J.
.I 1618
.T
Determination of the Square-Root of a Positive
Definite Matrix (Algorithm 298 [F1])
.A
Spath, H.
.I 1619
.T
Error-Free Methods for Statistical Computations
.W
Neely has discussed computational error generated
by some algorithms used to compute various
statistics.  In the present paper methods are described
which are error-free, simple in concept, and
usually less costly in machine time than those mentioned by Neely.
.A
Rodden, B. E.
.I 1620
.T
Methods of Evaluating Polynomial Approximations
in Function Evaluation Routines
.W
The method of nested multiplication is commonly
used in function evaluation routines to evaluate
approximation polynomials.  New polynomial evaluation
methods have been developed in recent years which
require fewer multiplications than nested multiplication
and may therefore be preferable for use in function
evaluation routines.  Although some of these methods
do not appear to be practically useful because of
rounding-error difficulties, several methods of evaluating
low-degree polynomials have been found to
be satisfactory.  Three such methods are described and illustrated.
.A
File, C. T.
.I 1621
.T
Computer Typesetting of ALGOL
.W
An application of computer-aided typesetting
is introduced.  A working method is described
for publishing ALGOL by computerized translation from
Hardware into Reference representation, computerized
planning of typographical lay-out and computerized control
of a typesetting machine.  The point is made
that experts in science, technology, and programming are
guaranteed a correct ALGOL documentation without
spending valuable time and power on typographic considerations and proofreading.
.A
Sydow, L. V.
.I 1622
.T
An Efficient Procedure for the Generation of Closed Subsets
.W
An efficient algorithm is described for generating
subsets of a set S which satisfy constraints
of the form: "If s(i) is a member of the subset, then
s(j) must also be a member of the subset."  The
algorithm has been programmed in the WISP language and
successfully run on the IBM 7094 in connection
with a routine to detect feedback in multidimensional iterative networks.
.A
Waite, W. M.
.I 1623
.T
An Application of FORMAC
.W
A nonlinear circuit analysis problem is stated
and the way in which it was solved using FORMAC
is indicated.  The solution of the problem using FORMAC
was notable since several other methods that
were tried failed.  The problem is straightforward (although
untenable by hand) but nevertheless involved
an elaborate use of the FORMAC language.  The program
was fairly large and utilized practically every
command.  In particular, it made extensive use of the
PART command.  Several tricks were necessary in
order to circumvent some of the shortcomings of the
FORMAC system.  This paper is more concerned with
the use of programming techniques in FORMAC than with
the actual engineering problem, although readers
may be interested in the problem because it is stated
in a general (mathematical) sense and could be
of interest in areas other than circuit analysis.
.A
Neidleman, L. D.
.I 1624
.T
Automatic Dimensioning
.W
Examples of algorithm that will accomplish
automatic storage reservation without the need for
explicit array declarations are described.
.A
Klerer, M.
May, J.
.I 1625
.T
On the Automatic Simplification of Source-Language Programs
.W
Methods of simplification that can be applied
automatically to programs written in an ALGOL-like
language are discussed.  The simplifications are based
on the form of the program and the knowledge obtained
by a processor, without any understanding of what the
program is supposed to do.  These methods have
been implemented in a processor called SURE that accepts
a program written in JOVIAL and outputs an equivalent
JOVIAL program that may be shorter and may be executed
faster than the original.  SURE is described,
some of the problems encountered in automatic improvement
at the source-language level are discussed,
and further types of automatic program improvement are suggested.
.A
Clark, E. R.
.I 1626
.T
Structure of a LISP System Using Two-Level Storage
.W
In an ideal list-processing system there would
be enough core memory to contain all the data
and programs.  Described in this paper are a number
of techniques that have been used to build a LISP
system utilizing a drum for its principal storage medium,
 with a surprisingly low time penalty for use
of this slow storage device.  The techniques include
careful segmentation of system programs, allocation
of virtual memory to allow address arithmetic for type
determination, and a special algorithm for building
reasonably linearized lists.  A scheme for binding variables
is described which is good in this environment
and allows for complete compatibility between compiled
and interpreted programs with no special declarations.
.A
Bobrow, D. G.
Murphy, D. L.
.I 1627
.T
Application of Level Changing to a Multilevel Storage Organization
.W
A technique for organizing the devices of a computer
storage system is described.  This technique,
called the multilevel store, provides a means for economically
satisfying the requirements for very large
storage capacities of certain data management and information
retrieval systems.  The concept of level
changing is introduced and its application to the multilevel
store is discussed.  A possible means for
physically organizing the information for efficient
use of the multilevel store is presented.
.A
Morenoff, E.
McLean, J. B.
.I 1628
.T
The Emergence of a Profession
.W
Computer programming deals with an enormous
variety of activities and is carried on by people
with a great variety of backgrounds.  It seems clear
that part but not all of this activity is evolving
toward a distinct professional field, but that the
scope of this emerging profession, and some of its
economic, social, and educational characteristics are
as yet by no means well defined.  In this paper,
these issues are examined and some opinions about them are expressed.
.A
Orden, A.
.I 1629
.T
Stat-Pack: A Biostatistical Programming Package
.W
A package of FORTRAN statistical programs for use
on almost any small to medium size (40k characters
or 8k words) for which a FORTRAN II compiler exists
is described and its availability is announced.
The major design criteria of ease of use, ease of modification,
flexibility of input and detail of output
are described.
.A
Shannon, S.
Henschke, C.
.I 1630
.T
Computer Representation of Planar Regions by Their Skeletons
.W
Any region can be regarded as a union of maximal
neighborhoods of its points, and can be specified
by the centers and radii of these neighborhoods; this
set is a sort of"skeleton" of the region.  The
storage required to represent a region in this way is
comparable to that required when it is represented
by encoding its boundary.  Moreover, the skeleton representation
seems to have advantages when it is
necessary to determine repeatedly whether points are inside
or outside the region, or to perform set-theoretic
operations on regions.
.A
Pfaltz, J. L. Rosenfeld, A.
.I 1631
.T
Testing a Random Number Generator
.W
The first 1,000,000 numbers produced by the
random number generator used in the General Purpose
Systems Simulator (GPSS) were subjected to statistical
tests.  The tests are described and the results
of the tests are presented.  These particular tests indicate
that the numbers are satisfactory.  It is
recommended that suitable tests be applied to all
random numbers used in computer simulations.
.A
Gorenstein, S.
.I 1632
.T
Programming the Tabular Method of Analysis
of Variance for Factorial Experiments
.W
The ease of programming the tabular method of analysis
of variance for complete factorial experiments
in a FORTRAN language is demonstrated.  In this method,
the total sum of squares is partitioned into
orthogonal single degree of freedom sums of squares;
main effect and interaction sums of squares are
then obtained by appropriate pooling of the single degree
of freedom sums of squares.  Program segments
to accomplish the procedure are presented.  Modifications
to handle hierarchical designs and replicated
experiments are mentioned. A FORTRAN II program
for an IBM 7094 is described briefly.
.A
Carmer, S. G.
.I 1633
.T
A Modified Newton Method for Polynomials
.W
A modified Newton method for polynomials is
discussed.  It is assumed one has approximations
for all the roots of the polynomial.  Three variations
are described.  If the roots are simple, it is
shown that under appropriate conditions, two
of the variations are cubically convergent.
.A
Ehrlich, L. W.
.I 1634
.T
27 bits Are Not Enough for 8-digit Accuracy
.W
From the inequality 10^8 < 2^27, we are likely
to conclude that we can represent 8-digit decimal
floating-point numbers accurately by 27-bit floating-point
numbers.  However, we need 28 significant
bits to represent some 8-digit numbers accurately.
In general, we can show that if 10^p < 2^q-1, then
q significant bits are always enough for p-digit decimal
accuracy.  Finally, we can define a compact
27-bit floating-point representation that will give 28
significant bits, for numbers of practical importance.
.A
Goldberg, I. B.
.I 1635
.T
Parameters for Pseudo Runge-Kutta Methods
.W
The object of this note is to present a choice
of the free parameters in the third- and fourth-order
pseudo Runge-Kutta methods involving two points. This
choice of parameters causes a bound on the principal
part of the truncation error term to be near the minimum
for the fourth-order method and at the minimum
for the third-order method.
.A
Byrne, G. D.
.I 1636
.T
Invariant Imbeding and the Numerical Integration
of Boundary-Value Problems for Unstable Linear
Systems of Ordinary Differential Equations
.W
In such diverse areas as radiative transfer
in planetary atmospheres and optimal guidance and
control, two-point boundary-value problems for unstable
systems arise, greatly complicating the numerical
solution.  An invariant imbeding technique is presented
which is useful in overcoming these frequently
encountered instabilities, and the results
of some numerical experiments are given.
.A
Belman, R. E.
Kagiwada, H. H.
Kalaba, R. E.
.I 1637
.T
Problems in the Statistical Analysis of Simulation
Experiments: The Comparison of Means and the
Length of Sample Records
.W
Research is continued into statistical analysis
of simulation experiments containing autocorrelated
time series.  It is shown how to estimate the lengths
of sample records needed to use certain large sample
results in measuring stability.  Analogies between autocorrelated
data and independent observations are
described.  A way to test the difference of the mean
of two experiments is suggested.  It is shown how
the variance of the sample mean relates to the spectrum
of the generating process, and estimation of
the quantities of interest is described. The results
expand the possibilities of statistical spectral
analysis as applied to simulation experiments.
.A
Fishman, G. S.
.I 1638
.T
Sorting by Replacement Selecting
.W
In sorting by replacement selecting, the expected
length of a sequence beginning with the i-th
element (i>1) is proved to be 2F, in accordance with
a conjecture of E. H. Friend, where F is the number
of memory cells used.  The expected length of the j-th
sequence is determined to be F times a j-th degree
polynomial in e, such that the value of this polynomial
approaches 2 as j approaches infinity.  Recursive
formulas are obtained for both the mean and the standard
deviation of the length of the j-th sequence.
 The mathematical proofs of these results are based
upon the assumption that n, the number of items to
be sorted, is infinite, but it is shown that the error
due to the finiteness of n approaches zero rapidly
as n increases.
.A
Gasner, B. J.
.I 1639
.T
Exponential Curve Fit (Algorithm 295 [E2])
.A
Spath, H.
.I 1640
.T
Generalized Least Squared Fit By Orthogonal
Polynomials (Algorithm 296 [E2])
.A
Makinson, G. J.
.I 1641
.T
A Use of Fast and Slow Memories in List-Processing Languages
.W
A scheme is described which permitting a substantial
increase in memory space utilized to store
list-structured data.  It consists in reducing to one
level a nonhomogeneous store composed of fast (core)
and slow (disk or drum) memories.  The space available
in slow memory is divided into pages each containing
a given number of machine words.  The reduction to a
one-level memory is performed by a program which
leaves the most often called pages in the fast memory.
 When a new page from slow store is requested,
the page in core having the longest period of inactivity
is transferred back to the slow store.  The
complete scheme has been implemented in connection with
a LISP embedding into ALGOL, using an IBM 7044
with 32k of core memory and disks.  Gains in memory space
were about 100-fold.  As often happens in programming
applications the price of the additional space is computer
time.  Although the disks have an access time
10^4 times slower than core, tests indicate that the
actual slow down varied from 3 to 10, depending
on the number of pages available in the fast store.
.A
Cohen, J.
.I 1642
.T
Time Sharing on a Computer with a Small Memory
.W
Techniques to make time sharing attractive on
a computer with a small central memory are presented.
 "Small" is taken to mean that only one user program plus
a monitor will fit into the memory at any time.
 The techniques depend on having two levels of secondary
storage: level 1, several times larger than
the main memory and quite fast; and level 2,
many times larger and slower than level 1.
.A
Fisher, R. O.
Shepard, C. D.
.I 1643
.T
An Improvement to Iterative Methods of Polynomial Factorization
.W
Methods of polynomial factorization which
find the zeros one at a time require the division
of the polynomial by the accepted factor.  It is shown
how the accuracy of this division may be increased
by dividing in order of both ascending and descending
powers of the variable and choosing a crossover
point which minimizes a very simply calculated error criterion.
.A
Bingham, J. A. C.
.I 1644
.T
On the Computation of Least Squares Polynomials
.W
Rounding error accumulated during digital computation
of a least squares polynomial makes the
computed polynomial only an approximation to the true least
square polynomial.  A simple method for adjust ing
the constant term of the computed polynomial to get
a better approximation to the true least squares
polynomial is described.
.A
Goldberg, M.
.I 1645
.T
A Note on Computing Approximations to the Exponential Function
.W
Two methods are discussed which result in near
minimax rational approximations to the exponential
function and at the same time retain the desirable property
that the approximation for negative values
of the argument is the reciprocal of the approximation
for corresponding positive values.  These methods
lead to approximations which are much superior to the
commonly used convergents of the Gaussian continued
fraction for the exponential.  Coefficients and errors
are given for the intervals [-.5*ln 2, .5*ln 2]
and [-ln 2, ln 2].
.A
Cody, W. J.
Ralston, A.
.I 1646
.T
DITRAN-A Compiler Emphasizing Diagnostics
.W
DITRAN (Diagnostic FORTRAN) is an implementation
of ASA Basic FORTRAN with rather extensive
error checking capabilities both at compilation time
and during execution of a program.  The need for
improved diagnostic capabilities and some objectives
to be met by any compiler are discussed.  Attention
is given to the design and implementation of DITRAN
and the particular techniques employed to provide
the diagnostic features.  The handling of error messages
by a general macro approach is described.  Special
features which provide teaching aids for use by instructors are noted.
.A
Moulton, P. G.
Muller, M. E.
.I 1647
.T
WATFOR-The University of Waterloo FORTRAN IV Compiler
.W
WATFOR is an in-core, load-and-go compiler
which has been implemented within the IBM 7040/44
operating system.  FORTRAN IV was selected as the source
language in order to achieve maximum language
compatibility with other available compiling systems,
in particular the IBM 7040/44 FORTRAN IV system.
 The principal advantage of the WATFOR compiler is that
it translates FORTRAN IV programs at speeds of
up to 100 statements per second.  Since the compiler
resides core there is virtually no system overhead,
and hence large batches of "student" programs may be processed very
efficiently.  The compiler also provides
extensive error diagnostics, during both the compilation
and the execution phases of a program run.
This feature makes the system attractive to
both learners and learned users alike.
.A
Shantz, P. W.
German, R. A.
Mitchell, J. G.
.I 1648
.T
Uniform Random (Algorithm 294 [G5])
.A
Strome, W. M.
.I 1649
.T
Data Directed Input-Output in FORTRAN
.W
A statement which is similar to the NAMELIST
statement of FORTRAN IV has been incorporated
in the FORTRAN 63 compiler.  The FORTRAN 63 implementation
allows a greater flexibility and simplicity
than the FORTRAN IV feature.  The Hollerith names, the
location, the mode and the dimensions of a variable
can be discovered by means of standard FORTRAN statements.
 Methods of using this information are illustrated
in relation to general purpose data directed input and
output routines; some other uses such as matrix
manipulation are discussed.
.A
Hassitt, A.
.I 1650
.T
A Unifying Computational Method for the
Analysis of Complete Factorial Experiments
.W
A computational method which may be used for
the calculation of sums of squares in the analysis
of variance of complete factorial experiments and in
the computation of main effect or interaction means
is described.  The method is elucidated as unifying since
one method can be used for a variety of purposes
each previously requiring different methods.  The programming
advantages of such a method are obvious.
 The following variants are discussed: (1) the standard
analysis of variance; (2) analyses omitting certain
levels of one or more factors; (3) separate analyses
for some levels of a factor or for combinations
of levels of more than one factor.  These are performed
simultaneously; (4) the calculation of main effect
or interaction means.  The mean expects the data in standard
order and it leaves the data in that order
so that many analyses of the same data can be performed
without rearrangement.  The total sum of squares,
excluding a replication sum of squares, is partitioned
into all polynomial partitions and their interactions
each with one degree of freedom.  This is so even
if factors have unequally spaced factor levels.
.A
Cooper, B. E.
.I 1651
.T
An Interpretive Input Routine for Linear Programming
.W
In this descriptive article an input code
is presented which greatly simplifies data input
to any linear programming solution routine, for subsequent
use either as a pedagogical device or for
solving rather small LP problems.  This latter (limited)
use derives not at all from inherent limitations
in the code itself, but from an efficiency evaluation:
large LP problems would doubtless benefit from
an input system more suited for bulk data handling than
the input code described.  From a user's standpoint,
input appears almost exactly as a textbook presentation
of the LP problem (limited only by a keypunch's
inability to write subscripts, etc.).  The input interpreter
scans column wise, thus no fixed format
data preparation is required.  The user may also, under
very general requirements only, liberally use
editorial comments throughout the input deck as an
aid in identification, e.g., of row constraints.
The article includes examples of input, output from a
solution routine presently in use, and a skeleton
flowchart of the input interpreter.
.A
Aigner, D. J.
.I 1652
.T
A Code for Non-numeric Information Processing
Applications in Online Systems
.W
A code has been specifically designed to simplify
the internal information processing operations
within an online computer system with respect to non-numeric
applications, and to maximize the transfer
rate of the information channel linking the system and
the system user.  The code has direct application
to problems in area such as information retrieval, document
classification, computer-aided teaching and
text editing.  This code, called IPC (Information Processing
Code), is an 8-bit code set constructed
so that 7, 6, 5 and 4-bit subsets can be easily derived
from the basic set.  The code set is organized
so that simple binary operations can distinguish between
the numeric alphabetic, special symbol and control
character codes.  The number of usable characters within
the basic set size may be expanded either by
use of escape codes included in the set, or by suitable
interpretation of otherwise unassigned codes
on the basis of the requirements of local environments.
.A
Morenoff, E.
McLean, J. B.
.I 1653
.T
System Performance Evaluation: Survey and Appraisal
.W
The state of the art of system performance
evaluation is reviewed and evaluation goals and
problems are examined.  Throughput, turnaround, and
availability are defined as fundamental measures
of performance; overhead and CPU speed are placed in
perspective.  The appropriateness of instruction
mixes, kernels, simulators, and other tools is discussed,
as well as pitfalls which may be encountered
when using them.  Analysis, simulation, and synthesis are
presented as three levels of approach to evaluation,
requiring successively greater amounts of information.
 The central role of measurement in performance
evaluation and in the development of evaluation methods is explored.
.A
Calingaert, P.
.I 1654
.T
A University's Educational Program in Computer Science
.W
After a review of the power of contemporary computers,
computer science is defined in several
ways.  The objectives of computer science education are
stated, and it is asserted that in a North American
university these will be achieved only through a computer
science department.  The program at Stanford
University is reviewed as an example.  The appendices
include syllabic of Ph.D. qualifying examinations
for Stanford's Computer Science Department.
.A
Forsythe, G. E.
.I 1655
.T
Code Extension Procedures for Information
Interchange* (Proposed USA Standard)
.K
standard code, code, information interchange, characters,
shift out, shift in, escape, data link
escape, control functions, standard procedures,
code extension, code table, bit pattern
.I 1656
.T
Procedures for the Standardization Process* (Proposed USA Standard)
.K
standardization, procedures, criteria
.I 1657
.T
Implementation of the SHARER2 Time-Sharing System
.W
A simple mechanism is described for the execution
of part of a program with its own memory
protection.  This allows such a program to act as a
suboperating system.  An improved version of the
SHARER time-sharing system using this feature is described.
.A
Harrison, M. C.
.K
operating system, memory protection, time-sharing,
multiprogramming, monitor, submonitor, suboperating
system
.I 1658
.T
Analysis of Algorithms for the Zero-One Programming Problem
.W
This paper is concerned with a review and examination
of several existing algorithms for the
zero-one programming problem.  Computational experience
is summarized.  The machine time and storage
requirements of several of the algorithms are compared
over several test problems of small and intermediate
size.  Computer experiments still provide little hope
of solving problems with over 100 variables with
a reasonable amount of machine time.
.A
Gue, R. L.
Liggett, J. C.
Cain, K. C.
.K
operations research, optimization theory, integer
programming, zero-one variables, algorithms
.I 1659
.T
Computational Linguistics in a Ph.D. Computer Science Program
.W
This report contains recommendations for a
course curriculum on computational linguistics in
a Ph.D. computer science program.  A classification of the
subject areas contained in computational linguistics
is presented, and ten courses in these areas are described.
 A basic bibliography in computational linguistics
is appended.
.A
Kuno, S.
Oettinger, A. G.
.K
computational linguistics, mathematical linguistics,
language and computer, language data processing,
computational linguistics course curriculum, computational
linguistics graduate program, computational
linguistics bibliography, computer science curriculum
.I 1660
.T
Index By Subject To algorithms, 1960-1968
.I 1661
.T
Multint (Algorithm 32 [D1])
.A
Kolbig, K. S.
.K
numerical integration, multidimensional integration, Gaussian integration
.I 1662
.T
Eigenvalues and Eigenvectors of a Real General Matrix [F2])
.A
Grad, J.
Brebner, M. A.
.K
eigenvalues, eigenvectors, latent roots, latent
vectors, Householder's method, QR algorithm, inverse
iteration
.I 1663
.T
Generator of Random Numbers Satisfying the Poisson distribution [G5])
.A
Snow, R. H.
.K
Poisson distribution, random number generator, Monte Carlo
.I 1664
.T
An Algorithm for Deriving the Equations of
Mathematical Physics by Symbolic Manipulation
.W
A method is described whereby a digital computer
can be used to derive the equations of mathematical
physics in any curvilinear coordinate system requested
by the user.  The effectiveness of the technique
is demonstrated by using it to derive the Navier-Stokes
equations of fluid motion and the continuity
equation.  To derive these equations by this method, the
user need know only the coordinate transformation
equations relating the curvilinear coordinates of interest
to an orthogonal Cartesian triad. When this
program is used and the coordinate transformation equations
are supplied as input, the computer will
derive the Navier-Stokes equations and the continuity
equation.  The equations obtained will be relative
to the curvilinear coordinate system specified by the
transformation equations used as input.  In this
paper the emphasis is on theoretical considerations and
methodology rather than on programming details.
 Results are presented for cylindrical polar
and spherical polar coordinate systems.
.A
Howard, J. C.
Tashjian, H.
.K
FORMAC, Navier-Strokes equations, continuity equation,
tensor, tensor equation, curvilinear coordinate
systems, FORTRAN, symbolic manipulation
.I 1665
.T
Automatic Generation of Efficient Lexical
Processors Using Finite State Techniques
.W
The practical application of the theory of
finite-state automata to automatically generate
lexical processors is dealt with in this tutorial article
by the use of the AED RWORD system, developed
at M.I.T. as part of the AED-1 system.  This system
accepts as input description of the multicharacter
items or of words allowable in a language given in terms
of a subset of regular expressions. The output
of the system is a lexical processor which reads a string
of characters and combines them into the items
as defined by the regular expressions.  Each output
item is identified by a code number together with
a pointer to a block of storage containing the characters
and character count in the item.  The processors
produced by the system are based on finite-state machines.
 Each state of a "machine" corresponds to
a unique condition in the lexical processing of a character
string.  At each state a character is read,
and the machine changes to a new state.  At each transition
appropriate actions are taken based on the
particular character read.  The system has been in operation
since 1966, and processors generated have
compared favorably in speed to carefully hand-coded programs
to accomplish the same task.  Lexical processors
for AED-O and MAD are among the many which have been
produced.  The techniques employed are independent
of the nature of the items being evaluated.  If the
word "events" is substituted for character string,
these processors may be described as generalized decision-making
mechanisms based upon an ordered sequence
of events.  This allows the system to be used in a
range of applications outside the area of lexical
processing.  However convenient these advantages may
be, speed is the most important consideration.
In designing a system for automatic generation of a
lexical processor, the goal was a processor which
completely eliminated backup or rereading, which was nearly
as fast as hand-coded processors, which would
analyze the language and detect errors, and
which would be convenient and easy to use.
.A
Johnson, W. L.
Porter, J. H.
Ackley, S. I.
Ross, D. T.
.K
character string, compiler, finite-state automata, finite-state
machine, lexical processor, nondeterministic
machine, parsing, plex structure, regular expressions,sequential
machine, syntactic analysis
.I 1666
.T
Solution of Linear Programs in 0-1 Variables
by Implicit Enumeration (Algorithm 341 [H])
.A
Byrne, J. L.
Proll, L. G.
.K
linear programming, zero-one variables, partial enumeration
.I 1667
.T
Roots of Polynomials by a Root-Squaring
and Resultant Routine (Algorithm 340 [C2])
.A
Noltemeier, A.
.K
root finders, roots of polynomial equations, polynomial
zeros, root-squaring operations, Graeffe
method, resultant procedure, subresultant procedure,
testing of roots, acceptance criteria
.I 1668
.T
An Algol Procedure for the Fast Fourier Transform
with Arbitrary Factors (Algorithm 339 [C6])
.A
Singleton, R. C.
.K
fast Fourier transform, multivariate Fourier transform,
Fourier series, harmonic analysis, spectral
analysis, orthogonal polynomials, orthogonal transformation,
virtual core memory, permutation
.I 1669
.T
Algol Procedures for the Fast Fourier Transform (Algorithm 338 [C6])
.A
Singleton, R. C.
.K
fast Fourier transform, complex Fourier transform,
multivariate Fourier transform, Fourier series,
harmonic analysis, spectral analysis, orthogonal polynomials,
orthogonal transformation, virtual core
memory, permutation
.I 1670
.T
Correspondences of 8-Bit and Hollerith Codes for
Computer Environments (A USASI Tutorial Standard)
.K
USA standard, card code, punched card, punched card
code, hole-patterns, hole-patterns assignment,
punched card systems
.I 1671
.T
A Phonological Rule Tester
.W
The design and implementation of a system to
alleviate the problem of rule evaluation for the
linguist in the area of phonology are presented.  It
permits the user to define, on-line, sets of rules
statable within the framework presented in The Sound
Patterns of English by Chomsky and Halle, 1968,
to define phonemes as bundles of specified distinctive
features, to define data as strings of phonemes
with associated grammatical structure, to test the effect
of applying rules to the data, and to store
both the definitions and results.  The rule application
facility described in detail was implemented
by translating linguistic rules to rules in FLIP, a
format-directed list processor embedded in LISP.
 This made the system construction easy while providing
sophisticated capabilities for the linguist.
 The system is written in BBN LISP on the Scientific
Data System 940 computer and is designed to be used
on-line in interactive fashion, with control returned
to the user after each command is executed.
.A
Borrow, D. G.
Fraser, J. B.
.K
phonology, rule tester, linguistics, transformational
grammar, LISP, format-directed list processing,
on-line systems
.I 1672
.T
Practical Error Coefficients in the Integration
of Periodic Analytic Functions by the Trapezoidal
Rule
.W
Theoretical and practical values of error coefficients
useful in bounding the error in integrating
periodic analytic functions with the trapezoidal rule
are tabulated for various ranges of the parameters.
.A
Rabinowitz, P.
.K
theoretical error coefficients, practical error coefficients,
numerical integration, periodic analytic
functions, trapezoidal rule, roundoff error,
truncation error, integration algorithm
.I 1673
.T
Approximate Solution of Initial Boundary Wave
Equation Problems by Boundary-Value Techniques
.W
A new boundary-value technique is proposed for
the treatment of initial-boundary-value problems
for linear and mildly nonlinear wave equations.   Several
illustrative examples are offered to demonstrate
the ease with which the method can be applied.
.A
Greenspan, D.
.K
initial-boundary-value problem, wave equation, boundary-value technique
.I 1674
.T
One-Line Random Number Generators and Their Use in Combinations
.W
Some one-line random number generators, i.e.
generators requiring a single FORTRAN instruction
are discussed, and some short FORTRAN programs which
mix several such generators are described.  The
aim is to provide methods for incorporating random number
generators directly in FORTRAN programs, by
means of a few in-line instructions.  The advantages are
speed (avoiding linkage to and from a subroutine),
convenience, and versatility.  Anyone wishing to experiment
with generators, either using congruential
generators by themselves or mixing several generators
to provide a composite with potentially better
statistical properties than the library generators
currently available, may wish to consider some of
the simple FORTRAN program discussed here.
.A
Marsaglia, G.
Bray, T. A.
.K
random number generation, Monte Carlo, simulation
.I 1675
.T
A Note on a Relevance Estimate and Its Improvement
.W
In this paper the effect of iterating the improvement
procedure is examined.  It is shown that
applications of the improvement factor beyond the first
time are ineffectual, and that the factor is
but a scale factor.
.A
Korfhage, R. R.
.K
information retrieval, relevance, indexing, classification
.I 1676
.T
The LRLTRAN Compiler
.W
Extensive software problems confront an organization
which possesses a number of different
computers and which frequently acquires new ones.
To maintain cohesion, a system must be developed,
written in a high level language, which minimizes machine
dependencies and isolates those which are necessary.
 A language and a compiler for the language are discussed
here.  The language, called LRLTRAN, is a heavily
augmented FORTRAN.  The tree-pass compiler makes use
internally of a postfix Polish notation (pass I
to pass II) and a tree representation referred to as
a "composite blocking table" (pass I to pass III).
 Machine-independent optimization occurs in pass II
and DO-loop and machine-dependent optimization in
pass III.
.A
Mendicino, S. F.
Martin, J. T.
Ranelletti, J. E.
Zwakenberg, R. G.
.K
compiler, compiler-compiler, machine independence,
scatter storage technique, Polish processor,
common subsegments, tree representation, optimization
.I 1677
.T
Storage Organization in Programming Systems
.W
The system of program and data representation
that has been in use on the Rice University computer
for five years is described.  Each logical entity in storage
occupies a block of consecutive memory locations.
 Each block is labeled by a codeword and may contain
a program, a data vector, or codewords which in
turn label blocks to form arrays.  This storage arrangement
is discussed with its realized advantages
or programming systems: simplicity of programmed addressing,
flexibility of data structures, efficiency
of memory utilization, variability of system composition
during execution, means of linkage between programs
and from programs to data, and basis for storage protection.
 The application of labeled blocks may be
extended to areas of time-sharing and multimedia storage
control.  On the basis of experience at rice,
some ideas on such extensions are presented.
.A
Jodeit, J. G.
.K
storage allocation, storage organization, storage
control, codewords, data representation, program
representation, data structures, storage protection,
addressing mechanisms, paging, segmentation, file
handling
.I 1678
.T
Automata, Formal Languages, Abstract Switching,
and Computability in a Ph.D. Computer Science
Program
.W
A number of courses are listed in the area
describe as automata, formal languages, abstract
switching, and computability, that might be available
to a Ph.D. student in computer science.  A brief
catalog description of each course is applied and the
role of each of the courses in the graduate program
is discussed.
.A
McNaughton, R.
.K
Ph.D. computer-science curriculum, Ph.D. computer
science program, automata, formal languages,
switching theory, theory of computability
.I 1679
.T
A Fast Fourier Transform Algorithm for Real-Valued Series
.W
A new procedure is presented for calculating the
complex, discrete Fourier transform of real-valued
time series.  This procedure is described for an example
where the number of points in the series is
an integral power of two.  This algorithm preserves
the order and symmetry of the Cooley-Turkey fast
Fourier transform algorithm while effecting the two-to-one
reduction in computation and storage which
can be achieved when the series is real.  Also discussed
are hardware and software implementations of
the algorithm which perform only (N/4) log2 (N/2) complex
multiply and add operations, and which require
only N real storage locations in analyzing each N-point record.
.A
Bergland, G. D.
.K
fast Fourier transform, time series analysis, digital
filtering, spectral analysis, real-time spectrum
analyzers, Fourier analysis, discrete Fourier transform,
digital spectrum analysis, Fourier analysis
algorithm, Fourier synthesis algorithm
.I 1680
.T
A General-Purpose Display Processing and Tutorial System
.W
ADEPT (A display-Expedited Processing and Tutorial)
system is described.  This system was designed
to improve man-computer communications by employing
a display unit to interleave tutoring with other
computer operations such as simulation, programming, and
information retrieval.  It is written in FORTRAN
IV (G) for the IBM System/360, Model 40, and the IBM 2250
display Unit under Operating System/360.  Adept
is a cataloged program that controls the standard operating
system by terminating and rescheduling itself
automatically, relinquishing computer resources allocated
to it, and surrendering control to the operating
system to perform other jobs.  It expands the power
and flexibility of computer-assisted instruction
by making immediately available to students, teachers,
and other users, the full resources (system-cataloged
programs) of the operating system.  Language processors
and compilers, simulation models, mathematical
solution techniques, stored data, and all other library and
user programs can be incorporated into instructional
material without reprogramming.  Illustrations of the various
applications are presented and their implications
are discussed.
.A
Engvold, K. J.
Hughes, J. L.
.K
computer-assisted instruction, tutorial systems,
programming, simulation, modeling, information
retrieval operating systems, graphics, displays, man-machine
interface, on-line computing, graphic programming
.I 1681
.T
Easy English,a Language for Information
Retrieval Through a Remote Typewriter Console
.W
Easy English is a natural command language
designed to simplify communication between man and
machine through remote typewriter console.  It has been developed
for retrieval of documents from a computerized
data base, the Moore School Information Systems Laboratory
files.  Requests are formulated in a standardized
syntactical form (examples of which are presented), and
this form is then transformed into an equivalent
query expressed in the retrieval system's original Symbolic
Command Language, which is briefly described.
 Operation of easy English is detailed by illustration
of the transformations performed upon a sample
request up to the point at which the request string
is sent to the system.  A macro flowchart of Easy
English is included, and an Appendix provides
the printout of a retrieval demonstration.
.A
Rubinoff, M.
Bergman, S.
Cautin, H.
Rapp, F.
.K
natural language communication, on-line searching,
remote console communication, information retrieval,
man-machine communication, remote terminal communication,
translator, document retrieval, conversational
mode, information retrieval language, symbolic command language
.I 1682
.T
The Implementation of a BASIC System in a Multiprogramming Environment
.W
The implementation of a remote terminal BASIC system
within the context of an existing multiprogramming
computer system, the Burroughs B5500, is described.
 This implementation combines a unique mixture of
machine language and interpretive techniques with an incremental compiler.
.A
Braden, H. V.
Wulf, W. A.
.K
multiprogramming, incremental compilation, compilers, interpreters
.I 1683
.T
Boolean matrix Methods for the Detection of Simple Precedence Grammars
.W
A mechanical procedure is derived for determining
whether a given context-free phrase structure
grammar is a simple precedence grammar.  This procedure
consists of elementary operations on suitably
defined Boolean matrices.  Application of the
procedure to operator grammars is also given.
.A
Martin, D. F.
.K
syntax analysis, precedence analysis, simple precedence
grammar, simple precedence language, operator
grammar, operator precedence, compilers, bounded-context
syntactic analysis, Boolean matrices, relations
.I 1684
.T
Ambiguity in Limited Entry Decision Tables
.W
The use of decision tables as a tool in systems
analysis and for program specification is now
becoming accepted.  Rules on redundancy, contradiction,
and completeness for limited entry tables were
published in 1963.  These are usually used for checking,
preceded if necessary by a conversion from extended
to limited entry form.  Processors which automatically
translate tables to more conventional program
usually base their diagnostic facilities on these rules.
 In this paper it is suggested that these rules
are unsatisfactory and that the important aspect of
checking is to eliminate ambiguity from tables.
Ambiguity is defined and discussed, and a procedure for
producing checked-out decision tables is proposed.
 The theoretical basis of the algorithm used is established.
The importance of well-designed diagnostic
facilities in decision table processors is emphasized.
.A
King, P. J. H.
.K
decision tables, DETAB-65, systems analysis
.I 1685
.T
GAN, a System for Generating and Analyzing Activity Networks
.W
GAN, a system for generating activity networks,
is designed to save time in the preparation
of activity networks and to deal conveniently with network
programs.  A defining description of a programming
language designed for generating activity network from
a set of standard networks is presented.  Also,
a general idea of a language for performing calculations
on activity networks (scheduling activity networks)
is given.
.A
Schurmann, A.
.K
activity network, management project, standard network,
network generator, network assembler, activity
network analysis, network calculation, network program
.I 1686
.T
Computer Synthesis of Holograms for 3-D Display
.W
Optical and digital holography are reviewed.
 The mathematical model and computational techniques
of the authors' digital holographic process are discussed,
and applications of computer holography are
suggested.  Computer holograms have been made of three-dimensional
objects which give faithful reconstructions,
even in white light.  A new approach based on point
apertures for the image is discussed.  Photographs
of the images reconstructed from digital holograms are presented.
.A
Lesem, L. B.
Hirsch, P. M.
.K
holography, optics, Fourier transforms, computer
applications, display device, photography, physics,
mathematics, image processing
.I 1687
.T
Netflow (Algorithm 248 [H])
.A
Bray, T. A.
Witzgall, C.
.K
capacitated network, linear programming, minimum-cost
flow, network flow, out-of-kilter
.I 1688
.T
Netflow (Algorithm 248 [H])
.A
Henderson, J. H.
.K
capacitated network, linear programming, minimum-cost
flow, network flow, out-of-kilter
.I 1689
.T
Calculation of a Polynomial and its Derivative
Values by Horner Scheme (Algorithm 337 [C1])
.A
Pankiewicz, W.
.K
function evaluation, polynomial evaluation,
Algol procedure, Horner's scheme
.I 1690
.T
Netflow (Algorithm 336 [H])
.A
Bray, T. A.
Witzgall, C.
.K
capacitated network, linear programming, minimum-cost
flow, network flow, out-of-kilter
.I 1691
.T
A Comparison of the Correlational Behavior
of Random Number Generators for the IBM 360
.W
Hutchinson states that the "new" (prime modulo)
multiplicative congruential pseudorandom generator,
attributed to D. H. Lehmer, has passed the usual statistical
tests for random number generators.  It
is here empirically shown that generators of this type
can produce sequences whose autocorrelation functions
up to lag 50 exhibit evidence of nonrandomness for many
multiplicative constants.  An alternative generator
proposed by Tausworthe, which uses irreducible polynomials
over the field of characteristic two, is shown
to be free from this defect.  The applicability of these
two generators to the IBM 360 is then discussed.
 Since computer word size can affect a generator's statistical
behavior the older mixed and simple congruential
generators, although extensively tested on computers
having 36 or more bits per word, may not be optimum
generators for the IBM 360.
.A
Whittlesey, J. R.
.K
random numbers, pseudorandom number generators, autocorrelation
function, serial correlation, digital
shift-register generators, linear recurrence modulo
two, irreducible polynomials, primitive trinomials
modulo two, congruential generators, prime numbers,
statistical tests for randomness, IBM 360, 32-bit
versus 36-bit word size
.I 1692
.T
Numerical Solution of a Thin Plate Heat Transfer Problem
.W
The numerical solution of a system of linear
equations resulting from a discrete approximation
to a thin plate heat transfer problem is considered.
 The slow convergence of point iterative methods
is analyzed and shown to be caused by one of the boundary
conditions. The difficulty may be removed by
a standard line iterative technique.
.A
Stewart III, G.W.
Lick, D. W.
.K
heat transfer problem, Poisson equation, boundary
value problem, thin domain, successive overrelaxation
(SOR), block SOR
.I 1693
.T
GPL, a Truly General Purpose Language
.W
A truly general purpose programming language,
GPL, is described which contains facilities for
constructing (within the language) new data types as
well as facilities for operations performed upon
them.  The basic language is minimal in the sense that
no basic element can be derived from the others
with high efficiency in the object programs.  Constructs
like the ALGOL 60 for-statements,and if-statements
are not basic; they are special types of procedures.
 New "symbols" (underlined words in ALGOL 60) are
implicitly defined by usage in other declarations.  As
part words are definable, packed words are handled
as easily as full words.  "Address" variables
(pointers) are included in full generality.
.A
Garwick, J. V.
.K
programming language, general purpose, self-extending, macro, ALGOL
.I 1694
.T
An Algorithm for the Probability of
the Union of a Large Number of Events
.W
An algorithm is presented which efficiently evaluates
the probability for the union of n independent
and not mutually exclusive events. The problem is that
of evaluating the sums of the products of all
possible combinations of n variables in minimum time and storage space.
.A
Miller, G. D.
.K
algorithm, probability, optimum, storage vs. time
compromise, set union, mutually exclusive events
.I 1695
.T
PLEXUS-An On-Line System for Modeling Neural Networks
.W
A description is presented of PLEXUS, a system
which enables a user to construct and specify
a neural network, to analyze the output data produced
by the network, and to store and retrieve networks
and data from a library.  The system, operated entirely
from a digital display unit, interacts directly
with the user and permits easy and rapid transitions
between the various phases of the modeling process.
 PLEXUS is designed to complement neurophysiological research
so that the systematic development of neural
models can be coordinated with experimental work.  PLEXUS
networks are built up from components representing
individual neurons, external stimuli, and interconnecting
fibers, each component being of a relatively
detailed nature.  Provision is also made for the use of
experimental data as input to a network.  Convenient
means for specification and modification of a network and
extensive error-checking capabilities are provided.
Data resulting from the simulation of a network may be
analyzed by a variety of techniques ranging from
examinations of the gross characteristics of the data to
the determination of detailed statistical properties.
.A
Dill, J. C.
Randall, D. L.
Richer, I.
.K
biological modeling, data analysis, discrete system
simulation, library systems, modeling, network
simulation, neural networks, neurophysiological
models, on-line simulation, simulation
.I 1696
.T
An Algorithm for Identifying the Ergodic Subchains
and Transient States of a Stochastic Matrix
.W
An algorithm for identifying the ergodic subchains
and transient states of a stochastic matrix
is presented.  Applications in Markov renewal programming
and in the construction of variable length
codes are reviewed, and an updating procedure for dealing
with certain sequences of stochastic matrices
is discussed.  Computation times are investigated experimentally
and compared with those of another recently
propose method.
.A
Fox, B. L.
Landi, D. M.
.K
stochastic matrix, ergodic, chain identification
.I 1697
.T
Graphical Input/Output of Nonstandard Characters
.W
A system developed at Harvard for graphically
inputting and outputting nonstandard characters
on a computer is printed.  In principle, the system
can deal with any orthography, although at present
it is limited to 4000 Chinese characters and some mathematical
symbols.  New characters can be added
to the repertoire of the system by graphical input on
a display scope.  Text inputting is accomplished
via a display scope or a Rand Tablet.  The organization
and operation of the current system are described,
and a discussion of the relative merits of such a system
is given.  Illustrations of the computer input
and output of Chinese characters are included.
.A
Hayashl, H.
Duncan, S.
Kuno, S.
.K
Chinese characters, input/output, orthography, Rand
Tablet, PDP-1, automatic typesetting, man-machine
communication, computer graphics, graphical input, on-line editing
.I 1698
.T
A Statistical Model for Console Behavior in Multiuser Computers
.W
The ability of a computer system to communicate
with the outside world efficiently is as important
as its ability to perform computations efficiently.
It is quite difficult to characterize a particular
user, but rather easy to characterize the entire user community.
 Based on the properties of this community
we have postulated a hypothetical "virtual console."
 No claim is made that a virtual console behaves
like any actual console, but the entire collection of
virtual consoles models the collection of actual
consoles.  Using the model we answer questions like:
How many processes are suspended waiting for console
input?  What is the maximum rate at which a process can
execute?  What bounds can be set on overall buffer
requirements?  Answers to these and similar questions
are needed in certain aspects of operating system
design.
.A
Denning, P. J.
.K
statistical models for input-output, operating
system design, input-output design
.I 1699
.T
Experimental Evaluation of Information
Retrieval Through a Teletypewriter
.W
Experiments designed to evaluate the capabilities
of mechanized information retrieval systems,
with emphasis on interactive (man-machine) language and on
some of the mechanical and psychological limitations
in their design, were conducted at the Moore School information
Systems Laboratory.  The basic assumption
of the research is that an information retrieval system
that provides for man-machine dialogue at a remote
inquiry terminal should provide a searcher with many
of the tools which would be available to him were
he actually performing his search at a library or repository
of documents.  Factors involved in evaluation
of such a system include ease of use, learning time, and
effectiveness of actual retrieval.  Three experiments
and the conclusions resulting from them are detailed.
.A
Rubinoff, M.
Bergman, S.
Franks, W.
Rubinoff, E.R.
.K
information retrieval testing,  information system
evaluation, experimental document retrieval,
document retrieval, document perusal, man-machine communication,
remote console communication, teletypewriter
communication, remote terminal communication, retrieval
command language, symbolic command language,
interactive systems, user learning factors, on-line searching
.I 1700
.T
PEEKABIT, Computer Offspring of Punched
Card PEEKABOO, for Natural Language Searching
.W
The "peekaboo" idea from punched card information
retrieval methods has been mated with the
idea of superimposed punching to produce a programming
technique which cuts computer run time in half
on a test search of 33,000 subject index entries.  A search
program using the device has been operational
since late 1963.  As an item is entered in the store,
an 18-byte mask is created from the item's meaningful
words using the inclusive OR operation.  If, at search
time, the logical product (using the AND operation)
of this mask and a similarly constructed question mask
is not equal to the question mask, then one or
more question words are not present in the store item.
 An equality is in conclusive; the words of the
store item must be unpacked and compared with question
words.  The present store is made up of over 600,000
subject index entries estimated to average 60 characters
each.  Longer texts, such as abstracts, could
be handled by multiple masks.
.A
Hutton, F. C.
.K
peekaboo, superimposed coding, natural language
searching text searching, information compaction,
computer search technique
.I 1701
.T
Synchronous Signaling Rates for Data
Transmission* (Proposed USA STandard)
.I 1702
.T
Commentary on Mr. Mooers' Paper
.A
Steel Jr., T. B.
.I 1703
.T
Accommodating Standards and Identification of Programming Languages
.W
The user public wants standardization and
reliable identification of programming languages
and related services.  One way of achieving these goals
illustrated by the methods adopted for TRAC T-64
interactive language, and its related family of languages.
 Oppressive rigidity usually associated with
standardization is avoided by a new accommodation technique
accessible to the user to allow local variations
with the language.  Explicit standardization of the language
is undertaken at the organizational source
of the language.  Use of the organizational trademark
(TRAC) on the published standards, and services
relying upon them, provides a reliable public identification.
 These methods can be usefully applied
to other programming languages and computer services.
.A
Mooers, C. N.
.K
standardization, programming languages, TRAC T-64
language, tranemark, public identification of
programming languages, standards which accommodate
.I 1704
.T
Minimum Excess Cost Curve (ALgorithm 217 [H])
.A
Muth, J. F.
.K
critical path scheduling, PERT, cost/time tradeoffs, network flows
.I 1705
.T
A Set of Basic Input-Output Procedures (Algorithm 335 [15])
.W
By means of the primitives in symbol, outsymbol
and length, as requested by this journal's
Algorithms Policy [Comm. ACM 10 (Nov. 67), 729] a basic
set of input-output procedures is defined aiming
at quality and flexibility.  Outreal, for instance, is
written as a derived procedure; it outputs using
the fixed point or the floating point representation,
and rounds properly.  Variants can easily be written
because of the explicit call of the procedures decompose
integer and decompose real.  The highly recommended
practice of echoing input is made easy with one subset
of derived procedures (ioi, ior, iob, ioa).  The
documentation of output in the form of equivalent ALGOL
statements is also provided when use is made
of the subset oti, otr, otb, ota.  The Berkeley style
of providing information on the form of output
using prior calls of procedures such as real format is
defined.  A use of the parameter outchannel to
provide information for simultaneous output to several
channels is suggested.  Interrelationship between
the declared procedures is furnished in tabular form.
.A
De Vogelaere, R.
.K
input output, transput, input output procedures,
input echo, quality output, decompose integer,
decompose real, style, Berkeley style, procedures relationship,
output documentation, equivalent ALGOL
statements, ALGOL, ALGOL 60, integer format, real format,out
integer, read real, input output Boolean,
input output array, fixed point representation, floating
point representation, output channel interpretation
.I 1706
.T
CHAMP-Character Manipulation Procedures
.W
A new programming language facility for symbol
manipulation is described.  String procedures
may be declared and called in a standard ALGOL context.
 ALGOL procedures can in turn be called by string
procedures so that numeric and symbolic processes may
conveniently be programmed together.  Concatenation
and a variant of SNOBOL's pattern matching make up
a set of primitive commands.  These are assembled
together into conditional expressions which are to be
used to provide alternative computational patterns.
 Arrays of strings are processed using quantifiers.
 The class of things which may be assigned to an
identifier can be restricted by a procedure expressed
in the notation.  The language facilities have
been implemented in the ALGOL compiler for the Burroughs B5500.
.A
Storm, E. F.
.K
symbol manipulation, string handling, character
manipulation, conditional expressions, procedures,
structure matching, recursive programming, quantifiers
.I 1707
.T
Generation of Positive Test Matrices with Known Positive Spectra
.W
Sufficient conditions are given for a real
matrix to be similar to a positive matrix.  This
result is used to construct a similarity transformation
which, when applied to a particular upper triangular
matrix, yields a positive matrix with a preassigned positive spectrum.
.A
Hall, C. A.
Porsching, T. A.
.K
test matrices, positive matrices, similarity
transformation, positive eigenvalues
.I 1708
.T
A Note on the Efficiency of a LISP Computation in a Paged Machine
.W
The problem of the use of two levels of storage
for programs is explored in the context of
a LISP system which uses core memory as a buffer for
a large virtual memory stored on a drum.  Details
of timing are given for one particular problem.
.A
Borrow, D. G.
Murphy, D. L.
.K
storage management, list processor implementation,
LISP, paging, secondary storage utilization,
efficiency of paged computation
.I 1709
.T
A Modification of Efroymson's Technique for Stepwise Regression Analysis
.W
The computational technique conventionally used
for stepwise multiple linear regression requires
the storage of an n X n matrix of data.  When the number
of variables, n, is large, this requirement
taxes the storage capacity of presently used machinery.
 The near symmetry of the matrices involved permits
a modification requiring only half the storage and computations
of the conventional algorithm and this
additional storage allows the analysis of problems containing
more variables.  Alternatively, it permits
the analysis of problems containing the same number
of variables but with all computations performed
in double precision.
.A
Breaux, H. J.
.K
multiple linear regression, statistical recurrence
formulas, correlation, linear statistical models,
statistical computer programs, curve fitting
.I 1710
.T
ASP-A Ring Implemented Associative Structure Package
.W
ASP is a general purpose Associative Data
Structure Package in which an arbitrary number of
data items and an arbitrary number of the relationships
between these data items may be represented.
 A special picture language is described which has proved
very useful for drawing ASP structures on paper.
 ASP structures are built and manipulated by means
of a series of macro calls, which are outlined in
the Appendix.  Emphasis is on the philosophy of the system
rather than a particular implementation, though
sufficient information is included to enable the
reader to produce his own implementation of ASP.
.A
Lang, C. A.
Gray, J. C.
.K
associative, data structure, ring structure lists,
list structure, set languages, modeling, graphics
.I 1711
.T
When Your Computer Needs a Lawyer
.W
Possible liability for negligence, for other
torts (such as slander of credit) and for liability
under theories of express or implied warranty (guarantees)
are discussed, and legal complications are
explained, so that users, operators, owners, and leasors
of computers may be alerted to potential legal
problems. Focus is also on trouble spots in contracting
for data processing services, in automating record
keeping operations, in deciding whether or not to automate
certain operations, and in complying with
statutes and regulation relating to record keeping.
 Information is given on patents, copyrights and
trade secret protection for programs, and the problem
of using copyrighted material in information storage
and retrieval systems, including the pending
copyright and patent revision bills.
.A
Banzhaf III, J. F.
.K
law, legal, lawyer, liability, torts, negligence,
contracts, warrantees, guarantees, accounting,
regulations, simulation, income tax, copyrights, patents,
trade secrets, standard of care, slander of
credit, crime, criminals, record keeping records, evidence, copying
.I 1712
.T
Recovery of Disk Contents After System Failure
.W
A method is discussed by which, after a system
malfunction, the contents of disk files can
be restored to their status at the time of the failure.
.A
Lockemann, P. C.
Knutsen, W. D.
.K
data acquisitition, disk file organization,
error recovery, file organization
.I 1713
.T
On Overcoming High-Priority Paralysis
in Multiprogramming Systems: A Case His tory
.W
High-priority paralysis is the degradation
that can occur in multiprogramming systems when
scheduling is based primarily on preassigned priorities.
 It can be alleviated by modifying the scheduling
algorithm to maximize the number of programs active
at one time.  The case his tory given in this paper
indicates two general methods by which simultaneity can
be increased.  Possible refinements in the scheduling
algorithm for future improvements are considered briefly.
.A
Stevens, D. F.
.K
multiprogram scheduling, dynamic priority assignment scheduling
.I 1714
.T
Procedure for the Normal Distribution (Algorithm 272 [S15])
.A
MacLaren, M. D.
.K
normal distribution function, error function,
normal function, normal curve integral
.I 1715
.T
Direct Search (Algorithm 178 [E4])
.A
De Vogelaere, R.
.K
function minimization, search, direct search
.I 1716
.T
Normal Random Deviates (Algorithm 334 [G5])
.A
Bell, J. R.
.K
normal deviates, normal distribution, random number,
random number generator, simulation, probability
distribution, frequency distribution, random
.I 1717
.T
Generating Prime Implicants Via Ternary Encoding and Decimal Arithmetic
.W
Decimal arithmetic, ternary encoding of cubes,
and topological considerations are used in an
algorithm to obtain the extremals and prime implicants
of Boolean functions. The algorithm, which has
been programmed in the FORTRAN language, generally requires
less memory than other minimization procedures,
and treats DON'T CARE terms in an efficient manner.
.A
Dietmeyer, D. L.
Duley, J. R.
.K
prime implicants, extremal, switching function,
minimization, cubical complexes, ternary encoding
.I 1718
.T
"Logical" Arithmetic on Computers
with Two's Complement Binary Arithmetic
.W
Algorithms are presented for multiplication
and division of unsigned integer operands in which
the digits normally reserved for signs participate as
significant arithmetic digits with positive weight.
.A
Ehrman, J. R.
.K
binary arithmetic, unsigned operand arithmetic,
maximum significance arithmetic, full-precision
arithmetic
.I 1719
.T
A Methodology for Calculating and
Optimizing Real-Time System Performance
.W
The continually increasing size, complexity,
number of types, and cost of data processing systems
are causing serious re-examination within government
and industry of the criteria for and methods of
calculating and optimizing data processing system cost
and performance.  Real-time data processing systems
as typified by the automated airline reservation system
are discussed in this paper.  Criteria for evaluating
performance are described; a methodology for calculating
and optimizing is outlined; and the method is
illustrated by carrying out a portion of the performance
calculation and the optimization of a drum-oriented
message switching system.
.A
Stimler, S.
Brons, K. A.
.K
real-time system analysis, real-time system design,
real-time system performance criteria, real-time
system cost performance ratio
.I 1720
.T
Master's Level Computer Science Curricula
.W
The results of a survey of the course work done
by master's degree candidates at 25 US universities
are presented, and some general comments concerning
the emphasis of these programs are given.
.A
Elliott, R. W.
.K
surveys, education, computer science curricula
.I 1721
.T
Determination of the Intersection Points of Two
Plane Curves by Means of Differential Equations
.W
A new method is proposed to calculate the intersection
points of two plane curves.  The theory
of singular points off a system of two differential equations
is used in developing the method. The intersection
point to be determined is identified with such a singular
point and appropriate modifications are applied
to the system to ensure that the singular point be stable,
i.e. all integrals which start in the neighborhood
of the singular point will always approach this point
if the integral parameter tends to infinity.  In
addition a method is described for systematically searching
for all intersection points in a prescribed
rectangular area.
.A
Kuiken, H. K.
.K
plane curves, intersection points, intersections
plane curves, integration, differential equations,
matrix iteration, singular points, nonlinear differential
equations, eigenvalues, complex roots, roots,
stationary points, Runge Kutta, stable singularity, unstable singularity
.I 1722
.T
Methods of Convergence Improvement for Some Improper Integrals
.W
In the numerical integration of an improper
integral of the first kind, it is customary to
truncate the integral when the change yielded by the last
iteration is less than some predetermined constant.
The efficiency of such integration schemes can often
be improved by use of recent advances in the theory
of nonlinear transformations; however, for several important
integrals, e.g. integrals whose integrands
are rational polynomials, these transformations fail
to yield much improvement.  In this paper, several
methods of convergence improvement are developed which greatly
improve convergence of some improper integrals,
including the integrals of rational polynomials.
.A
McWilliams, G. V.
Thompson, R. W.
.K
approximation, nonlinear, improper integral, convergence
improvement, numerical integration, rational
polynomials, truncation
.I 1723
.T
Computer Construction of Project Networks
.W
Project networks are used in PERT and CPM.
 An algorithm is given for constructing project
networks directly from the project precedence relations.
 The algorithm creates "dummy" activities and
topologically orders the arcs and nodes.  The number of
nodes created is minimal for the given precedence
relations.  It has been experimentally programmed
in FORTRAN II for the IBM 7094.
.A
Fisher, A. C.
Liebman, J. S.
Nemhauser, G. L.
.K
project networks, PERT, CPM, topological
ordering, network construction by computer
.I 1724
.T
A Generalized Partial Pass Block Sort
.W
The design of a partial pass block sort with
arbitrary range of key and number of work files
is described. The design is a generalization of the Partial
Pass Column Sort by Ashenhurst and the Amphisbaenic
Sort by Nagler. The power of the sort is tabulated for
various sizes of input file and number of work
files. consideration is given to the problem of combining
a block sort with internal sorts, and to the
best use of direct access storage devices.
.A
Bayes, A.
.K
block sort, partial pass sort, direct access devices,
column sort, chaining, reverse chaining,
sort, amphisbaenic
.I 1725
.T
A Simple Proof of Lewin's Ordered-Retrieval
Theorem for Associative Memories
.W
An efficient method of ordered retrieval of binary
words from an associative memory, as described
by Lewin, is based on the use of special readout circuits
which indicate the digit values present in
the individual digit columns of the memory.  Thus the
circuits indicate whether the individual digit
columns contain digits of both values, or of only one
value, or contain no digits at all (i.e. that the
memory is empty).  The use of these circuits, which
in this paper are termed column value indicators,
reduces considerably the number of memory accesses necessary
to retrieve in order a number of distinct
words from the memory.  Lewin proves that, for the readout
by the described method of m distinct binary
words, 2m - 1 memory accesses are necessary.  (Thus he
proves that the number of necessary memory accesses
of his method, unlike those of other methods, is independent
of the word length.)  In this paper a very
simple proof of this theorem derived from some elementary
aspects of the structure of sets of binary
numbers is presented.
.A
Wolinsky, A.
.K
associative memories, content-addressed memories,
ordered lists, ordered information retrieval,
ordered retrieval theorem, column digit values, digit
value variety, column sensing arrangement, digit
value readout, digit variety readout, memory access, memory
access frequency, ordered retrieval efficiency,
access frequency proof, retrieval theorem proof
.I 1726
.T
Preliminary Investigation of Techniques
for Automated Reading of Unformatted Text
.W
Methods for converting unstructured printed
material into computer code are experimentally
investigated.  An operator-controlled mode, depending
on human demarcation of the various regions of
the page for guiding the scanner, is implemented by
means of a joystick and a CRT display.  This mode,
for which some performance figures are obtained, is thought
to be suitable for processing very complicated
material, such as technical journals.  For simpler material,
for instance the "claims" sections of patents,
and in applications where the utmost accuracy is not necessary,
an unsupervised mode is advocated.  Here,
the textual portions of the page are located during
a rapid prescan by a rudimentary form of frequency
analysis.  These areas are then rescanned at a higher
resolution suitable for character recognition.
 Error rates of the order of 0.1 percent are obtained in
a simple problem involving photographs of telephone
company meter boards.  Other matters related to the
design of a general purpose page reader, such as
the segmentation of printed text, the possibility of
time-sharing the scanner, interactive man-machine
operation, and the facsimile reproduction of illustrations, are discussed.
.A
Nagy, G.
.K
pattern recognition, character recognition, text
reading, information retrieval, unformatted text
operator-controlled reader, online reader,
text-image discrimination, reading machine
.I 1727
.T
One Way of Estimating Frequencies of Jumps in a Program
.W
For the segmentation of a program it is useful
to have a reasonable estimation of the values
of S(ij), where S(ij) is the mean value of the number
of jumps from the i-th instruction on to the j-th
instruction in the run time.  In the cases where the
S(ij) are estimated directly, the structure of the
whole program must be generally taken into account;
therefore it is very difficult for the programmer
and/or the translator to obtain a good estimation of
the S(ij).  It is easier to estimate not S(ij) but
the quantities P(ij)=S(ij)*C(i)/SUM[S(ij), j=1,N], where
C(i) is an arbitrary positive constant for each
i.  Although the P(ij) are, for each i, proportional to
S(ij), the estimation of P(ij) is easier, because
we must estimate only the "probabilities" of events
where instruction i is executed after instruction
I(i).  This estimation can often be done without considering
the structure of the whole program.  In
the first part of the paper, using the theory of the
Markov chains, an algorithm for the computation
of the S(ij) from the P(ij) is found, and some ways
of obtaining estimates of the P(ij) are given.  In
the second part a variant of this algorithm is derived,
avoiding the necessity of computation involving
large matrices.
.A
Kral, J.
.K
object program reduction, supervisor calls decreasing,
jump frequencies estimation, control transfers
estimation, optimal program segmentation, Markov chain
program correspondence, program graph, one-entry
subgraph, locally estimated jump frequencies, supervisor
overhead decreasing, program segmentation algorithm,
jump frequencies, program segmentation problem
.I 1728
.T
Further Experimental Data on the Behavior
of Programs in a Paging Environment
.W
Results are summarized from an empirical study
directed at the measurement of program operating
behavior in those multiprogramming systems in which
programs are organized into fixed length pages.
The data collected from the interpretive execution of
a number of paged programs are used to describe
the frequency of page faults, i.e. the frequency of those
instants at which an executing program requires
a page of data or instructions not in main (core) memory.
 These data are used also for the evaluation
of page replacement algorithms and for assessing the
effects on performance of changes in the amount
of storage allocated to executing programs.
.A
Coffman, E. G.
Varian, L. C.
.K
paging systems, paging, dynamic program behavior, program
behavior, virtual memory systems, single-level
storage, one-level storage, operating system simulation,
operating systems, supervisor simulation, machine
language program interpretation
.I 1729
.T
Minit Algorithm for Linear Programming (Algorithm 333 [H])
.A
Salazar, R. C.
Sen, S.K.
.K
linear programming, dual simplex method, primal problem, dual problem
.I 1730
.T
Jacobi Polynomials (Algorithm 332 [S22])
.A
Witte, B. F. W.
.K
Jacobi polynomials, orthogonal polynomials,
three-term recurrences, special functions
.I 1731
.T
Gaussian Quadrature Formulas (Algorithm 331 [D1])
.A
Gautschi, W.
.K
quadrature, Gaussian quadrature, numerical integration,
weight function, orthogonal polynomials
.I 1732
.T
Factorial Analysis of Variance (Algorithm 330 [G1])
.A
Oliver,I.
.K
factorial variance analysis, variance, statistical analysis
.I 1733
.T
Distribution of Indistinguishable Objects
into Distinguishable slots (Algorithm [G6])
.A
Fenichel, R. R.
.K
object distributions, combinations, distribution numbers
.I 1734
.T
Chebyshev Solution to an Overdetermined
Linear System (Algorithm 328 [F4])
.A
Bartels, R. H.
Goulub, H. G.
.K
Chebyshev solutions, overdetermined linear
systems, linear equations, exchange algorithm
.I 1735
.T
A Futures Market in Computer time
.W
An auction method is described for allocating
computer time that allows the price of computer
time to fluctuate with the demand and the relative priority
of users to be controlled so that more important
projects get better access.  This auction is free of the
periodic fluctuation in computer use often associated
with monthly time allocation schemes.
.A
Sutherland, I. E.
.K
computer scheduling, auction, time allocation, operating efficiency
.I 1736
.T
Heading Format for Data Transmission (A USAAI Tutorial -- Standards)
.K
data transmission heading format, heading format,
message format, data transmission, message headings
.I 1737
.T
A Global Parser for Context-Free Phrase Structure Grammars
.A
Unger, S. H.
.I 1738
.T
Writing an Outline Debugging Program for the Experienced User
.W
Presently available online debugging routines
are often unsatisfactory for the experienced
user because they require unnecessarily rigid and complicated
typing formats, make it difficult for the
user to correct typing errors, and consume excessive
memory with intricate features.  In a debugging
program it is of prime importance that the program
be simple, flexible, and highly efficient to use.
 Communication between the user and the debugging program
can be improved by using certain techniques
applicable to most online debugging programs.  These
techniques are presented and are illustrated by
their use in OPAK (octal package), a debugging program coded
for the PDP-5/8 and the SDS-930.  The compromise
between economy of utility program core storage and incorporation
of elegant debugging features is discussed.
.A
Brady, P. T.
.K
debugging, utility program, programming languages
.I 1739
.T
Regular Expression Search Algorithm
.W
A method for locating specific character strings
embedded in character text is described and
an implementation of this method in the form of a compiler
is discussed.  The compiler accepts a regular
expression as source language and produces an IBM 7094
program as object language.  The object program
then accepts the text to be searched as input and produces
a signal every time an embedded string in
the text matches the given regular expression.  Examples,
problems, and solution are also presented.
.A
Thompson, K.
.K
search, match, regular expression
.I 1740
.T
An Inexpensive Braille Terminal Device
.W
The active use of time-shared facilities for
blind programmers requires a braille terminal
system.  Details are given for the construction of a
brailler from a model 33 teletype by modifying the
print head and increasing the resiliency of the platen.
 A description of the programming needed to drive
the brailler is presented.
.A
Anderson, G. B.
Rogers, D. W.
.K
blind communication, blind programming aid, braille,
braille computer communication, braille output,
braille teletype, braille terminal, braille type head,
embosser, tactile computer communication, tactile
teletype, tactile terminal
.I 1741
.T
BRAD: The Brookhaven Raster Display
.W
A multiconsole computer display system has
been designed that provides very rich displays at
low unit cost.  Each BRAD (Brookhaven Raster Display)
console can plot tens of thousands of points, or
up to 4000 characters at 30 frames per second.  After
an initial display system investment of $50,000
each display, with teletype, costs less than $3,000.
 The technique employed is that of programmatically
generating a binary image of the desired display in a
computer.  The image is written on a rotating drum
memory.  Independent read heads continuously display
the picture, which is generated by swept horizontal
lines.  A standard TV monitor serves as the display device.
 The technique has two drawbacks.  A computer
must compute any image to be displayed.  Also, the "pointing"
interaction is more difficult.  This is
because the pointing function gives only the coordinates
of the point on the screen.  The inverse of
the map generation process is required to calculate
the coordinates of the point on the screen.  The
inverse of the map generation process is required to
calculate the coordinates at the selected point
in the input space.
.A
Ophir, D.
Rankowitz, S.
Shepherd, B. J.
Spinrad, R. J.
.K
computer display, computer graphics, computer raster
display, TV display console, digital TV display,
swept raster computer display, swept raster TV computer
display, TV graphics terminal, multiconsole computer
graphics, inexpensive graphic terminal
.I 1742
.T
On the Design of Display Processors
.W
The flexibility and power needed in the data
channel for a computer display are considered.
 To work efficiently, such a channel must have a sufficient number
of instructions that it is best understood
as a small processor rather than a powerful channel.
 As it was found that successive improvements to
the display processor design lie on a circular path, by
making improvements one can return to the original
simple design plus one new general purpose computer for
each trip around.  The degree of physical separation
between display and parent computer is a key factor in display processor design.
.A
Myer, T. H.
.K
display processor design, display system, computer
graphics, graphic terminal, displays, graphics,
display generator, display channel, display programming,
graphical interaction, remote displays
.I 1743
.T
Reliable Full-Duplex file Transmission over Half-Duplex Telephone Lines
.W
A field-proven scheme for achieving reliable
duplex transmission over a half-duplex communication
line is presented, and to demonstrate the difficulty
of the problem, another similar scheme, which is
only slightly unreliable, is also presented.  A flowchart
for the reliable scheme and some interesting
examples are given.
.A
Lynch, W. C.
.K
telephone communication, half duplex, transmission,
error correction, full duplex, telephone errors
.I 1744
.T
Stable Numerical Methods for Obtaining the Chebyshev
Solution to an Overdetermined System of
Equations
.W
An implementation of Stiefel's exchange algorithm
for determining a Chebyshev solution to an
overdetermined system of linear equations is presented,
that uses Gaussian LU decomposition with row
interchanges.  The implementation is computationally more
stable than those usually given in the literature.
 A generalization of Stiefel's algorithm is developed which
permits the occasional exchange of two equations
simultaneously.
.A
Bartels, R. H.
Golub, G. H.
.K
Chebyshev solutions, overdetermined linear
systems, linear equations,exchange algorithm
.I 1745
.T
A Position Paper on Computing and Communications
.W
The effective operation of free enterprise in
creating the envisioned information service industry
is dependent upon three accomplishments: (1) the restructuring
of our information processing industry
so that a clear division of costs is made among computing,
communications, and the development of information
services; (2) the wide use of multiaccess system concepts
so that information services may share in the
use of computer installations and so that the cost of their
construction is reasonable; and (3) the development
of public, message-switched communications services so
that adequate provisions are made for information
security.
.A
Dennis, J. B.
.K
information networks, information systems, computing
and free enterprise, computing economics,
computer installation management, government regulation,
communications services, distributed data base,
program leasing
.I 1746
.T
Protection in an Information Processing Utility
.W
One of the critical problems in the design
of an information processing utility that permits
flexible sharing of user information is privacy.
 One solution for this problem is discussed.
.A
Graham, R.M.
.K
protection, privacy, information processing utility,
time-sharing, multi-user, multiprogramming,
multiprocessing, security, shared information, controlled
access, reliable operation, segmentation
.I 1747
.T
Three Criteria for Designing Computing Systems to Facilitate Debugging
.W
The designer of a computing system should adopt
explicit criteria for accepting or rejecting
proposed system features.  Three possible criteria of this
kind are input recordability, input specifiability,
and asynchronous reproducibility of output.  These criteria
imply that a user can, if he desires, either
know or control all the influences affecting the content
and extent of his computer's output.  To define
the scope of the criteria, the notion of an abstract
machine of a programming language and the notion
of a virtual computer are explained.  Examples of applications
of the criteria concern the reading of
a time-of-day clock,  the synchronization of parallel
processes, protection in multiprogrammed systems,
and the assignment of capability indexes.
.A
Van Horn, E. C.
.K
computer design, computer design criteria, computer
systems, computer systems design, input equipment,
input equipment design, operating systems, operating
systems design, multiprogramming, multiprogrammed
systems, multiprogrammed system design, virtual computers,
programming languages, programming language
design, program semantics, programming language semantics,
determinism, reproducibility, repeatability,
deterministic computers, protection, memory protection,
information security, information privacy, computing
reliability, debugging, program debugging, program testing,
parallel processing, parallel programming,
multiprocessing
.I 1748
.T
A Scheduling Philosophy for Multiprocessing Systems
.W
A collection of basic ideas is presented, which
have been evolved by various workers over the
past four years to provide a suitable framework for the
design and analysis of multiprocessing systems.
 The notions of process and state vector are discussed,
and the nature of basic operations on processes
is considered.  Some of the connections between processes
and protection are analyzed.  A very general
approach to priority-oriented scheduling is described,
and its relationship to conventional interrupt
systems is explained.  Some aspects of time-oriented
scheduling are considered. The implementation of
the scheduling mechanism is analyzed in detail and the
feasibility of embodying it in hardware established.
 Finally, several methods for interlocking the execution
of independent processes are presented and compared.
.A
Lampson, B. W.
.K
time-sharing, multiprocessing, process, scheduling,
interlocks, protection, priority, interrupt
systems
.I 1749
.T
The Structure of the "THE"-Multiprogramming System
.W
A multiprogramming system is described in
which all activities are divided over a number of
sequential processes.  These sequential processes are placed
at various hierarchical levels, in each
of which one or more independent abstractions have been
implemented.  The hierarchical structure proved
to be vital for the verification of the logical soundness
of the design and the correctness of its implementation.
.A
Dijkstra, E. W.
.K
operating system, multiprogramming system, system
hierarchy, system structure, real-time debugging,
program verification, synchronizing primitives, cooperating
sequential processes, system levels, input-output
buffering, multiprogramming, processor sharing, multiprocessing
.I 1750
.T
Considerations in the Design of a Multiple
Computer System with Extended Core Storage
.W
The use of large quantities of addressable
(but not executable) fast random access memory to
heighten the multiprogramming performance of a multicomputer system
is discussed.  The general design
of the hardware arrangement and the software components
and functions of such a system are based on a
planned configuration of dual CDC 6600's that share one
million words of extended core storage.  In the
generalization of such a design, special emphasis is
placed on estimating expected gains when compared
with the traditional configuration of separate and independent
computers without extended core storage.
 An observation is made on the use of conventional, slower
speed, random access storage devices in place
of the faster memory.
.A
Fuchel, K.
Heller, S.
.K
multiple computer systems, extended core storage,
multiprogrammed operating systems, multiprocessor
operating systems, control data corporation 6600, operating system with ECS
.I 1751
.T
The Working Set Model for Program Behavior
.W
Probably the most basic reason behind the absence
of a general treatment of resource allocation
in modern computer systems is an adequate model for
program behavior.  In this paper a new model, the
"working set model," is developed. The working set
of pages associated with a process, defined to be
the collection of its most recently used pages, provides
knowledge vital to the dynamic management of
paged memories.  "Process" and "working set" are shown to
be manifestations of the same ongoing computational
activity; then "processor demand" and "memory demand"
are defined; and resource allocation is formulated
as the problem of balancing demands against available equipment.
.A
Denning, P. J.
.K
general operating system concepts, multiprocessing,
multiprogramming, operating systems, program
behavior, program models, resource allocation, scheduling, storage allocation
.I 1752
.T
Resource Management for a Medium Scale Time-Sharing Operating system
.W
Task scheduling and resource balancing for
a medium size virtual memory paging machine are
discussed in relation to a combined batch processing
and time-sharing environment.  A synopsis is given
of the task scheduling and paging algorithms that were implemented,
and the results of comparative simulation
are given by tracing the development of the algorithms
through six predecessor versions.  Throughout
the discussion particular emphasis is placed on balancing
the system performance relative to the characteristics
of all the system resources.  Simulation results relative
to alternate hardware characteristics and the
effects of program mix and loading variations are also presented.
.A
Oppenheimer, G.
Weizer, N.
.K
time-sharing, operating systems, resource management,
task scheduling, paging, system simulation,
memory management, virtual memories
.I 1753
.T
Virtual Memory, Processes, and Sharing in MULTICS
.W
Some basic concepts involved in the design
of the MULTICS operating system are introduced.
 MULTICS concepts of processes, address space, and virtual
memory are defined and the use of paging and
segmentation is explained.  The means by which users
may share procedures and data is discussed and the
mechanism by which symbolic references are dynamically
transformed into virtual machine addresses is
described in detail.
.A
Daley, R. C.
Dennis, J. B.
.K
virtual memory, information sharing, shared procedures,
data sharing, dynamic linking, segmentation,
paging, multiprogramming, storage management,
storage hierarchies, file maintenance
.I 1754
.T
Dynamic Storage Allocation Systems
.W
In many recent computer system designs, hardware
facilities have been provided for easing the
problems of storage allocation.  A method of characterizing
dynamic storage allocation systems-according
to the functional capabilities provided and the underlying
techniques used-is presented.  The basic purpose
of the paper is to provide a useful perspective from
which the utility of various hardware facilities
may be assessed.  A brief survey of storage allocation
facilities in several representative computer
systems is included as an appendix.
.A
Randell, B.
Kuehner, C. J.
.K
segmentation, paging, multiprogramming, storage
allocation, storage management, virtual memories,
storage fragmentation, storage hierarchies, addressing mechanisms
.I 1755
.T
Proceedings of the ACM Symposium on Operating system Principles
.A
ACM Special Interest Committee
.I 1756
.T
Hollerith Punched Card Code* (Proposed USA Standard)
.K
USA Standard, card code, punched card, punched card
code, hole-patterns, hole-patterns assignment,
punched card systems
.I 1757
.T
Data Code for Calendar Date for Machine-to-Machine
Data Interchange* (Proposed USA Standard)
.K
USA Standard, data code, calendar date, machine-to-machine
data interchange, recording calendar
date, data group identifier
.I 1758
.T
Symmetric Polynomials, (Algorithm 305 [C1])
.A
McKay, S.
.K
symmetric polynomials, symmetric sum, unitary
symmetric functions, Schur functions
.I 1759
.T
Transportation Problem (Algorithm 293 [H])
.A
Bayer, G.
.K
transportation problem, linear programming
.I 1760
.T
Normal Curve Integral (Algorithm 304 [S15])
.A
Bergson, A.
.K
normal curve integral, probability, special functions
.I 1761
.T
Chi-Squared Integral (Algorithm 299 [S15])
.A
O'Brien, W. M.
Wood, J.
.K
chi-squared integral, probability, special functions
.I 1762
.T
Dilogarithm (Algorithm 327 [S22])
.A
Kolbig, K. S.
.K
dilogarithm function, special functions
.I 1763
.T
Roots of Low-Order Polynomial Equations (Algorithm 326 [C2])
.A
Nonweiler, T. F.
.K
root finders, polynomial equation roots, quadratic
equation roots, cubic equation roots, biquadratic
equation roots, polynomial zeros
.I 1764
.T
Panel Discussion on Computer Appreciation
.W
Session 19 of the ACM 20 th Anniversary Conference
on August 31, 1967, was entitled Education,
Design Experiments, and Computer Appreciation.  Its second
half consisted of a panel discussion on computer
appreciation, organized and chaired by Elliot I. Organick.
 The four panelists were Charles H. Davidson,
Bernard A. Galler, Richard, W. Hamming, and Alan J. Perlis.
 After making prepared statements, the panelists
were joined in discussion by Andries van Dam and Arthur
B.Kohn, who had presented papers in the first
half.  This is a transcript of the panel discussion,
condensed by Dr. Organick and edited by him and
the panelists.  Some remarks referred to papers by van
Dam and Kahn or to the discussion during the first
half of the session.  Pertinent papers are included in the references.
.A
Organick, E. I.
.K
computer appreciation, students' liberal arts courses,
survey courses, beginning programming, course
content, computer courses dropout rates, college versus
precollege, teaching and social responsibility
.I 1765
.T
Expenditures, Sources of Funds, and Utilization
of Digital Computers for Research and Instruction
in Higher Education: 1964-65 with Projections for 1968-69
.W
The Southern Regional Education Board published
a complete report on a survey it conducted
to determine the funding and characterize the utilization
of computers used for research and instruction
in institutions of higher education in the United States.
The sampling survey is described and the estimates
for this total population are presented.
.A
Hamblen, J. W.
.K
computing centers, research, instruction, utilization,
expenditures, support, sources of funds,
higher education, post secondary education, colleges, universities
.I 1766
.T
Quasilinearization and the Estimation
of Differential Operators from Eigenvalues
.W
Given a linear ordinary differential operator
containing several unknown constants and a number
of its eigenvalues, the values of the unknown constants
are estimated.  A precise formulation is provided,
and an effective numerical procedure for solution is indicated.
  The results of some computational experiments
are given.
.A
Bellman, R. E.
Kagiwada, H. H.
Kalaba, R. E.
Vasudenvan, R.
.K
quasilinearization, eigenvalues, differential operators,
nonlinear boundary-value problems, inverse
problems,differential equations, system identification
.I 1767
.T
A General Purpose Graphic Language
.W
Interactive use of computers with graphic terminals
will permit many new problems to be solved
using machines.  In order to handle a variety of applications,
it is expedient to develop a general purpose
graphic language that is useful on a number of graphic
devices.  A system has been designed to produce
such a language quickly and cheaply.  A model graphic
language which has been developed with the system
is presented.
.A
Kulsrud, H. E.
.K
graphic language, interactive, incremental compilation,
language design, metacompiler, syntax specified
language
.I 1768
.T
A Global Parser for Context-Free Phrase Structure Grammars
.W
An algorithm for analyzing any context-free phrase
structure grammar and for generating a program
which can then parse any sentence in the language (or
indicate that the given sentence is invalid) is
described. The parser is of the "top-to-bottom" type
and is recursive . A number of heuristic procedures
whose purpose is to shorten the basic algorithm by quickly
ascertaining that certain substrings of the
input sentence cannot correspond to the target nonterminal
symbols are included.  Both the generating
algorithm and the parser have been implemented in RCA
SNOBOL and have been tested successfully on a number
of artificial grammars and on a subset of ALGOL.  A
number of the routines for extracting data about
a grammar, such as minimum lengths of N-derivable strings
and possible prefixes, are given and may be
of interest apart from their application in this particular context.
.A
Unger, S. H.
.K
parser, syntax-directed compiler, context-free
grammars, syntactic analysis, translators
.I 1769
.T
The Expanding World of Computers
.W
The onward sweep of automatic processing of
information is impeded by nine principal barriers:
geography, cost, problem complexity, man-machine communication,
inadequate sensors, lack of understanding,
distance, time, and size.  The main incentive for breaching
these barriers is the universal need for
processing information, ever more urgent as the greater
part of human work activity changes from production
to service.  Computer developments in hardware, programming,
time-sharing, education, data communication,
and displays are judged by how effectively they remove these
barriers, and their barrier-smashing potentialities
indicate continued rapid expansion.  Problem-oriented
languages are particularly effective over the entire
front.  Online computers and time-sharing also rate high
by this measure.  Education and increased understanding
are basic to all progress with the computer.  This complex
but powerful tool is the most important one
available to governments and scientists to use in studying
the problems being created by the population
explosion, and in analyzing possible solutions.
.A
Harder, E. L.
.K
barriers, philosophy, developments, computer-aided design,
problem-oriented languages, data communication,
education, computer science, forecast, survey, introduction
.I 1770
.T
Rules of Ethics in Information Processing
.W
The background and motivation for the adoption
by the ACM Council on November 11, 1966, of
a set of Guidelines for Professional Conduct in Information
Processing are described.  A brief his tory
is given of ethical codes in other professions.  Some
reasons for and against adoption of ethical rules
are considered, and several sections of the ACM Guidelines
are analyzed.  The purpose is to inform about
this important aspect of our profession, as
well as to stimulate thought and interest.
.A
Parker, D. B.
.K
ethics, professional conduct, code of ethics, ACM
guidelines, professionalism, professional societies,
unethical conduct
.I 1771
.T
CURRICULUM 68 -- Recommendations for Academic
Programs in Computer Science -- A Report of the
ACM Curriculum Committee on Computer science
.W
This report contains recommendations on academic
programs in computer science which were developed
by the ACM Curriculum Committee on Computer Science.
 A classification of the subject areas contained
in computer science is presented and twenty-two courses
in these areas are described.  Prerequisites,
catalog descriptions, detailed outlines, and annotated
bibliographies for these courses are included.
 Specific recommendations which have evolved from the
Committee's 1965 Preliminary Recommendations are
given for undergraduate programs.  Graduate programs in computer
science are discussed and some recommendations
are presented for the development of master's degree programs.
 Ways of developing guidelines for doctoral
programs are discussed, but no specific recommendations
are made. The importance of service courses,
minors, and continuing education in computer science is
emphasized.  Attention is given to the organization,
staff requirements, computer resources, and other facilities
needed to implement computer science educational
programs.
.K
computer science courses, computer science curriculum,
computer science education, computer science
academic programs, computer science graduate programs,
computer science undergraduate programs, computer
science course bibliographies
.I 1772
.T
USASCSOCR Dual Case Keyboard Arrangement* (Proposed USA Standard)
.I 1773
.T
General Purpose Alphanumeric Keyboard Arrangement
for Information Interchange* (Proposed USA
Standard)
.I 1774
.T
Program Overlay Techniques
.W
The general features of program overlay systems
are described.  Three main types -- automatic,
semiautomatic and nonautomatic -- are classified, and the
programming techniques are explained as a function
of machine hardware and other system features.  The
implementation of semiautomatic overlay facility
in a multiprogrammed system on the CDC 6600 is described
in detail, with special reference to real time
applications.
.A
Pankhurst, R. J.
.K
loaders, multiprogramming, overlay techniques,
storage allocation and segmentation
.I 1775
.T
Adjustment of the Inverse of a Symmetric Matrix
when Two Symmetric Elements are Changed (Algorithm
325 [F1])
.A
Zielke, G.
.K
symmetric matrix, matrix inverse, matrix
perturbation, matrix modification
.I 1776
.T
Maxflow (Algorithm 324 [H])
.A
Bayer, G.
.K
network,liner programming, maximum flow
.I 1777
.T
Generation of Permutations in Lexicographic Order (Algorithm 323 [G6])
.A
Ord-Smith, R. J.
.K
permutations, lexicographic order, lexicographic
generation, permutation generation
.I 1778
.T
F-Distribution (Algorithm 322 [S14])
.A
Dorrer, E.
.K
Fisher's  F-distribution, Student's t-distribution
.I 1779
.T
t-Test Probabilities (Algorithm [S14])
.A
Morris, J.
.K
T-test, Student's t-statistic, distribution function
.I 1780
.T
Harmonic Analysis for Symmetrically
Distributed Data (Algorithm 320 [C6])
.A
Hunter, D. B.
.K
harmonic analysis, cosine series, sine series, function
approximation, curve fitting, trigonometric
series
.I 1781
.T
Translator Writing systems
.W
A critical review of recent efforts to automate
the writing of translators of programming languages
is presented.  The formal study of syntax and its application
to translator writing are discussed in
Section II.  Various approaches to automating the post syntactic
(semantic) aspects of translator writing
are discussed in Section III, and several related topics in Section IV.
.A
Feldman, J.
Gries, D.
.K
compiler, compiler-compiler, translator, translator
writing systems, metacompiler, syntax, semantics,
syntax-directed, meta-assembler, macroprocessor,
parser, syntactic analysis, generator
.I 1782
.T
A Numerical Integration Formula Useful in Fourier Analysis
.W
A numerical integration formula is presented which
uses unequal sampling intervals.  The intervals
are equally spaced on a log scale.  Such a formulation
is useful in Fourier analysis to improve accuracy
and ease of usage.  A complete set of formulas
for numerical Fourier analysis is given.
.A
Meisel, W. S.
.K
numerical integration, Fourier analysis, integration
.I 1783
.T
In-and-Out Conversions
.W
Byan in-and-out conversion we mean that a floating-point
number in one base is converted into
a floating-point number in another base and then converted
back to a floating-point number in the original
base.  For all combinations of rounding and truncation
conversions the question is considered of how
many significant digits are needed in the intermediate
base to allow such in-and-out conversions to return
the original number (when possible), or at least significant digit.
.A
Matula, D. W.
.K
floating-point numbers, significance,
base conversion, rounding, truncation
.I 1784
.T
Practical Error Coefficients for Estimating
Quadrature Errors for Analytic Functions
.W
All published error coefficients for estimating
quadrature errors for analytic functions were
computed on the assumption that the quadrature rule
was exact for polynomials up to a given degree.
Since these rules use rounded values for the abscissas and
weights and since the true values of the integrals
of some of the polynomials in question have an infinite
binary expression, the quadrature rule is not
exact.  Hence these errors must be taken into consideration
in computing practical error coefficients.
.A
Rabinowitz, P.
.K
numerical integration, quadrature, truncation
error, theoretical error coefficients, practical
error coefficients, integration analytical functions, roundoff error
.I 1785
.T
Scatter Storage Techniques
.W
Scatter storage techniques as a method for
implementing the symbol tables of assemblers and
compilers are reviewed and a number of ways of using
them more effectively are presented.  Many of the
most useful variants of the techniques are documented.
.A
Morris, R.
.K
scatter storage, hash addressing, searching,
file searching, file addressing, storage layout
.I 1786
.T
An Improved Hash Code for Scatter Storage
.W
Introduced is a hash coding method based on
fixed-point division rather than multiplication
or logical operations.  This new method allows the
hash table to have almost any length.  Also a new
method of handling collisions is discussed.  Known as
quadratic search, this method is faster than random
search and free from the "clusters" that build up with a linear search.
.A
Maurer, W. D.
.K
hash code, hash table, scatter storage, searching
.I 1787
.T
Use of Transition Matrices in Compiling
.W
An algorithms is described which constructs
from a suitable BNF grammar an efficient left-right
recognizer for sentences of the corresponding language.
 The type of recognizer, used in a number of
compilers, operates with a pushdown stack and with
a transition matrix.  Two examples illustrate how
such recognizers may be used effectively for other
purposes besides the usual syntax checking.
.A
Gries, D.
.K
transition matrices, compilation, translation,
grammar, context-free language, formal language,
parsing
.I 1788
.T
Toward a General Processor for Programming Languages
.W
Many efforts have been made to develop a better
way of implementing a higher level programming
language than by the construction of a whole new compiler,
but so far none has proved generally satisfactory.
 In this paper, it is contended that a programming
language is best described functionally as a body
of macro instructions, and that the macro call constitutes
a canonical form in terms of which a programming
notation may be described.  A supporting discussion of the
logical and his torical role of the macro instruction
is presented.  Also discussed are the conflict between
machine independence and object program efficiency,
and the question of where the greatest difficulties
lie in compiler construction.
.A
Halpern, M. J.
.K
programming language translator, programming language
processor, general translator, general processor,
macro instruction processor; meta processor, meta language
translator, meta language processor, compiler-compiler,
writing system, translator writing system
.I 1789
.T
Logarithm of Gamma Function (Algorithm 291 [S14])
.A
Hoare, M. R.
.I 1790
.T
Muller's Method for Finding roots of an
Arbitrary Function  (Algorithm 196 [C5])
.A
Whitley, V. W.
.K
equation roots, function zeros
.I 1791
.T
Triangular Factors of Modified Matrices (Algorithm 319 [F1])
.A
Green, D. R.
.K
matrix decomposition, matrix factors,
matrix modifier, matrix perturbation
.I 1792
.T
Exploratory Experimental Studies Comparing
Online and Off line Programming Performance
.W
Two exploratory experiments were conducted at
System Development Corporation to compare debugging
performance of programmers working under conditions
of on-line and off line access to a computer.  These
are the first known studies that measure programmers'
performance under controlled conditions for standard
tasks.  Statistically significant results of both experiments
indicated faster debugging under online
conditions, but perhaps the most important practical finding
involves the striking individual differences
in programmer performance.  Methodological problems encountered
in designing and conducting these experiments
are described; limitations of the findings are pointed
out; hypotheses are presented to account for results;
and suggestions are made for further research.
.A
Sackman, H.
Erikson, W. J.
Grant, E. E.
.K
online vs. off line performance, programmer/computer
communication, programming experimental-empirical
studies, programming cost effectiveness, programming
performance, debugging effectiveness, time sharing
vs. batch processing, factor analysis application,
programmer trainee performance, basic programming
knowledge test, experienced programmer study, analysis
of variance, programmer individual differences
.I 1793
.T
Presentation of Alphameric Characters for Information
Processing* (Proposed American National
Standard)
.K
alphameric, handwritten input, encoding transcription,
numerals, upper case, hand printed
.I 1794
.T
A Fast Random Number Generator for IBM 360
.A
Seraphin, D. S.
.K
pseudorandom number, modulus, period, float,
normalization, characteristic, chi-square test
.I 1795
.T
Optimal Code for Serial and Parallel Computation
.A
Fateman, R. J.
.K
code optimization, sequencing of operations,
detection of common subexpressions
.I 1796
.T
Index by Subject to Algorithms, 1969
.K
This 1969 index is the first supplement to the
Index by Subject to Algorithms, 1960 1968 (Comm.
ACM 11, 12 (Dec. 1968), 827 830).
.I 1797
.T
Solution of Linear programs in 0-1 (Algorithm 341 [H])
.A
Proll, L. G.
.K
linear programming, zero-one variables, partial enumeration
.I 1798
.T
Coulomb Wave Functions (Algorithm 300 [S22])
.A
Kolbig, K. S.
.K
Coulomb wave functions, wave functions,
special functions, function evaluation
.I 1799
.T
Elementary Functions by Continued Fractions (Algorithm 229 [B1])
.A
Bray, T. A.
.K
continued factions, Pade table
.I 1800
.T
PSIF (Algorithm 147 [S14])
.A
Parsons, R. G.
.K
gamma function, logarithmic derivative, factorial function, psi function
.I 1801
.T
Analysis of Variance for Balanced Experiments (Algorithm 367 [G2])
.A
Claringbold, P. J.
.K
analysis of variance, analysis of covariance, regression
analysis, experimental design, balanced
experiment, missing data, interblock estimate, intra block estimate
.I 1802
.T
Regression Using Certain Direct Product Matrices (Algorithm 366 [G2])
.A
Claringbold, P. J.
.K
analysis of variance, analysis of covariance,
regression analysis, experimental design, matrix
direct product, protection operator, orthogonal matrix
.I 1803
.T
Complex Root Finding (Algorithm 365 [C5])
.A
Bach, H.
.K
downhill method, complex relaxation method, complex
iteration, complex equation, transcendental
complex equation, algebraic complex equation
.I 1804
.T
Coloring Polygonal Regions (Algorithm 364 [Z])
.A
Herriot, R. G.
.K
coloring polygonal regions, coloring planar surfaces,
drawing pictures, shading enclosed regions
.I 1805
.T
Productivity of Multiprogrammed Computers-Progress
in Developing an Analytic Prediction Method
.W
Multiprogramming as it is discussed here is
a mode of computer operation in which two or more
programs are concurrently in processor memory and proceeding,
each using the same central processor unit
(CPU) and input-output (I/O) channels.  These programs
are actually proceeding intermittently and singly,
according to eligibility (readiness to proceed) and priority.
 It is useful to be able to represent them
as proceeding continuously and simultaneously, each
at an effective rate, which may be a fraction of
that which it would enjoy in the absence of the other
programs.  The effective progress rate of each
program is sensitive to many detailed characteristics
of itself and its co-residents and simulation has
been the best available method of predicting it.  This
paper presents the results of progress in developing
an alternative to simulation, a simulation-tested iterative
computation of these rates under certain
situations.  The algorithm is sensitive to most of the
factors that control the phenomenon, including
nonquantitative or topological features of the programs' structures.
.A
Lasser, D. J.
.K
productivity, prediction, multiprogramming, simulation,
equipment  evaluation, hardware, evaluation,
monitor, operating system, system software, supervisors,
performance, time sharing, time slicing
.I 1806
.T
On the Downhill Method
.W
The downhill method is a numerical method for
solving complex equations f(z) = 0 on which the
only restriction is that the function w = f(z) must
be analytical.  An introduction to this method is
given and a critical review of relating literature is
presented.  Although in theory the method always
converges, it is shown that a fundamental dilemma exists
which may cause a breakdown in practical applications.
 To avoid this difficulty and to improve the rate of
convergence toward a root, some modifications of
the original method are proposed and a program (FORTRAN)
based on the modified method is given in Algorithm
365.  Some numerical examples are included.
.A
Bach, H.
.K
downhill method, complex relaxation method, complex
iteration, complex equation, transcendental
complex equation, algebraic complex equation
.I 1807
.T
Optimization of Expressions in Fortran
.W
A method of optimizing the computation of
arithmetic and indexing expressions of a Fortran
program is presented.  The method is based on a linear
analysis of the definition points of the variables
and the branching and DO loop structure of the program.
 The objectives of the processing are (1) to
eliminate redundant calculations when references are
made to common subexpression values, (2) to remove
invariant calculations from DO loops, (3) to efficiently
compute subscripts containing DO iteration variables,
and (4) to provide efficient index register usage.  The
method presented requires at least a three-pass
compiler, the second of which is scanned backward.  It
has been used in the development of several FORTRAN
compilers that have proved to produce excellent object
code without significantly reducing the compilation
speed.
.A
Busam, V. A.
England, D. E.
.K
FORTRAN, optimization, expressions, compilers,
compilation, subscripts, register allocation, DO
loops, common subexpressions, invariant calculations
.I 1808
.T
Advanced Cryptographic Techniques for Computers
.W
Cryptographic techniques which can be used to
maintain the confidentiality of information processed
by computers are dealt with.  Special emphasis is paid
to the unique characteristics of computer files
that make many cryptographic methods of little use.
 Relative security, costs, and preferred methods
are included in this paper.
.A
Van Tassel, D.
.K
cryptographic, cryptanalysis, ciphers secrecy systems,
security systems, confidential information
processing
.I 1809
.T
Numerical Analysis in a Ph.D. Computer Science Program
.W
Numerical Analysis is the study of methods and
procedures used to obtain "approximate solutions"
to mathematical problems.  Much of the emphasis is on scientific
calculation.  The difficulties of education
in such a broad area center around the question of background
and emphasis.  The Numerical Analysis program
in the Computer Science Department should emphasize an
awareness of the problems of computer implementation
and experimental procedures.  Nevertheless, there is a
need for a solid background in applied mathematics.
.A
Parter, S. V.
.K
Ph.D. program, numerical analysis, course separation, education
.I 1810
.T
Is Automatic "Folding" of Programs Efficient Enough To Displace Manual?
.W
The operation of "folding" a program into
the available memory is discussed.  Measurements
by Brown et al. and by Nelson on an automatic folding
mechanism of simple design, a demand paging unit
built at the IBM Research Center by Belady, Nelson,
O'Neil, and others, permitting its quality to be
compared with that of manual folding, are discussed,
and it is shown that given some care in use the
unit performs satisfactorily under the conditions tested,
even though it is operating across a memory-to-storage
interface with a very large speed difference.  The disadvantages
of prefolding, which is required when
the folding is manual, are examined, and a number of
the important troubles which beset computing today
are shown to arise from, or be aggravated by, this
source.  It is concluded that a folding mechanism
will probably become a normal part of most computing systems.
.A
Sayre, D.
.K
paging, automatic paging, demand paging, folding,
automatic folding, storage hierarchies, memory
hierarchies, replacement algorithms, performance, measurement
.I 1811
.T
A Case Study in Programming for Parallel-Processors
.W
An affirmative partial answer is provided to
the question of whether it is possible to program
parallel-processor computing systems to efficiently decrease
execution time for useful problems.  Parallel-processor
systems are multiprocessor systems in which several of
the processors can simultaneously execute separate
tasks of a single job, thus cooperating to decrease
the solution time of a computational problem. The
processors have independent instruction counters, meaning
that each processor executes its own task program
relatively independently of the other processors.  Communication
between cooperating processors is by
means of data in storage shared by all processors.  A
program for the determination of the distribution
of current in an electrical network was written for a
parallel-processor computing system, and execution
of this program was simulated.  The data gathered from
simulation runs demonstrate the efficient solution
of this problem, typical of a large class of important
problems.  It is shown that, with proper programming,
solution time when N processors are applied approaches
1/N times the solution time for a single processor,
while improper programming can actually lead to an increase
of solution time with the number of processors.
 Stability of the method of solution was also investigated.
.A
Rosenfeld, J. L.
.K
parallel-processor, parallelism, parallel programming,
multiprocessor, multiprogramming, tasking,
storage interference, electrical network, simulation,
relaxation, Jacobi, Gauss-Seidel, convergence
.I 1812
.T
More on Fortran Random Number Generators
.A
Grosenbaugh, L. R.
.K
random number generation, Monte Carlo, simulation
.I 1813
.T
Generation of Permutations in Pseudo-Lexicographic
Order (Algorithm 308 [G6])
.A
Ord-Smith, R. J.
.K
permutations, lexicographic order, lexicographic
generation, permutation generation
.I 1814
.T
Direct Search (Algorithm 178 [E4])
.A
Smith, L. B.
.K
function minimization, search, direct search
.I 1815
.T
Direct Search (Algorithm 178 [E4])
.A
Tomlin, F. K.
Smith, L. B.
.K
function minimization, search direct search
.I 1816
.T
Generalized Least Squares Fit By Orthogonal
Polynomials (Algorithm 296 [E2])
.A
Watson, W. T.
.K
least squares, curve fitting, orthogonal polynomials,
three-term recurrence, polynomial regression,
approximation, Forsythe's method
.I 1817
.T
Computation of Fourier Coefficients (Algorithm 255 [C6])
.A
Hall, G.
Ray, V. A.
.K
numerical integration, Fourier coefficients, Filon's method
.I 1818
.T
Associated Legendre Functions of the First Kind
for Real or Imaginary Arguments (Algorithm 47
[S16])
.A
Cobb, S. M.
.K
Legendre function, associated Legendre
function, real or imaginary arguments
.I 1819
.T
Complex Error Function (Algorithm 363 [S15])
.A
Gautschi, W.
.K
error function for complex argument, Voigt function,
Laplace continued fraction, Gauss-Hermite
quadrature, recursive computation
.I 1820
.T
Generation of Random Permutations (Algorithm 362 [G6])
.A
Robson, J. M.
.K
permutation, random permutation, transposition
.I 1821
.T
Permanent Function of a Square Matrix I and II (Algorithm 361 [G6])
.A
Shriver, B.
Eberlein, P. J.
Dixon, R. D.
.K
matrix, permanent, determinant
.I 1822
.T
Shortest-Path Forest with Topological Ordering (Algorithm [H])
.A
Dial, R. B.
.K
shortest path, tree, network, directed graph
.I 1823
.T
Factorial Analysis of Variance (Algorithm [G1])
.A
Howell, J. R.
.K
factorial variance analysis, variance, statistical analysis
.I 1824
.T
APAREL-A Parse-Request Language
.W
APAREL is described: this language is an extension
to an algorithmic language (PL/I) that provides
the pattern-matching capabilities normally found only
in special purpose languages such as SNOBOL4 and
TMG.  This capability is provided through parse-requests
stated in a BNF-like format.  These parse-requests
form their own programming language with special sequencing
rules.  Upon successfully completing a parse-request,
an associated piece of PL/I code is executed.  This
code has available for use, as normal PL/I strings
the various pieces (at all levels) of the parse.  It
also has available as normal PL/I variables, the
information concerning which of the various alternatives
were successful.  Convenient facilities for
multiple input-output streams, the initiation of sequences
of parse-requests as a subroutine, and parse-time
semantic checks are also included.  APAREL has proven convenient
 in building a powerful SYNTAX and FUNCTION
macro system, an algebraic language preprocessor debugging
system, an on-line command parser, a translator
for Dataless Programming, and as a general string manipulator.
.A
Balzer, R. M.
Farber, D. J.
.K
text processing, string processing, symbol manipulation,
PL/I, BNF, syntax, parser, translator,
pattern matching
.I 1825
.T
A Practical Method for Constructing LR(k) Processors
.W
A practical method for constructing LR(k) processors
is developed.  These processors are capable
of recognizing and parsing an input during a single
no-backup scan in a number of steps equal to the
length of the input plus the number of steps in its
derivation.  The technique presented here is based
on the original method described by Knuth, but decreases
both the effort required to construct the processor
and the size of the processor produced.  This procedure
involves partitioning the given grammar into
a number of smaller parts.  If an LR(k) processor can be
constructed for each part (using Knuth's algorithm)
and if certain conditions relating these individual
processors are satisfied, then an LR(k) processor
for the entire grammar can be constructed for them.
 Using this procedure, an LR(1) parser for ALGOL
has been obtained.
.A
Korenjak, A. J.
.K
LR(k) grammar, syntactic analysis, parser, deterministic
language, syntax-directed compiler, language
processor, context-free language ALGOL
.I 1826
.T
A LISP Garbage-Collector for Virtual-Memory Computer Systems
.W
In this paper a garbage-collection algorithm
for list-processing systems which operate within
very large virtual memories is described.  The object
of the algorithm is more the compaction of active
storage than the discovery of free storage.  Because free
storage is never really exhausted, the decision
to garbage collect is not easily made; therefore,
various criteria of this decision are discussed.
.A
Fenichel, R. R.
Yochelson, J. C.
.K
garbage-collector, virtual memory, list-processing, storage-allocation
.I 1827
.T
Performance Monitoring in a Time-Sharing System
.W
A software measurement facility which is part of
a general purpose time-sharing system is described.
 The Date Collection Facility (DCF) has been implemented
in the Michigan Terminal System (MTS) for the
System/360 model 67.  It exists for the purpose of monitoring
operating system and user program behavior
and performance.  The overall structure of MTS is outlined
in order to explain the implementation of
the DCF.  Events in the system are identified and recorded
from within the supervisor, and dumped to
magnetic tape by an auxiliary program for off-line processing.
 Events in user programs which are unrelated
to system actions are recorded with a supervisor call.
 The time of occurrence of each event is accurately
recorded, and data items are further identified by job and
type.  The overhead associated with data collection
and its interference with normal jobs is carefully analyzed,
and both are shown to be minimal.  Several
examples are given of information obtained with the
facility and of applications in which it has been
useful.  Some general guidelines are offered for
the construction of future monitoring programs.
.A
Pinkerton, T. B.
.K
performance monitoring, performance measurement,
program behavior, performance data, multiprogramming
performance, software measurement, time-sharing performance,
system evaluation, software monitor, software
instrumentation
.I 1828
.T
Synchronization in a Parallel-Accessed Data Base
.W
The following problem is considered:  Given
a data base which can be manipulated simultaneously
by more than one process, what are the rules for synchronization
which will maximize the amount of parallel
activity allowed.  It is assumed that the data base
can be represented as a graph.  An example of such
a data base is a hierarchy of directories for an on-line
file system.  Methods for synchronization of
processes are examined; their validity is
discussed and their performance compared.
.A
Shoshani, A.
Bernstein, A. J.
.K
parallel accessing, parallel search, file search,
data base, synchronization, locking, deadlock
.I 1829
.T
An Interactive Graphical Display Monitor in
a Batch-Processing Environment with Remote Entry
.W
A graphic monitor program is described.  It
was developed at Carnegie-Mellon University for
the CDC G21 computer, which is a general purpose, batch-processing
system with remote entry.  The existing
G21 system and the graphics hardware are described.
The graphic monitor is a resident auxiliary monitor
which provides comprehensive managerial capability
over the graphical system in response to commands
from the human user.  It also will respond to commands
from a user program through a similar interface,
where routine calls take the place of manual actions.  Thus
the human and program can interact on a symmetrical
and equal basis through the medium of the graphic monitor.
 The choice made in designing the graphic
monitor, given the constraints of the existing hardware
and computer system, are discussed.  The structure
of the monitor program and the human and program interfaces
are described.  There is also a transient
swapping version with a small resident part,
and provision for swapped used submonitors.
.A
Bond, A. H.
Rightnour, J.
.K
graphic monitor, man/machine interaction, graphic
interface, graphic in batch environment, design
of graphical system
.I 1830
.T
Retrieval Times for a Packed Direct Access Inverted File
.A
Bayes, A. J.
.K
information retrieval, direct access memory, data base, inverted list
.I 1831
.T
A Comment on Optimal Tree Structures
.A
Stanfel, L. E.
.K
information retrieval, file searching, tree structures, double chaining
.I 1832
.T
Minimax Logarithmic Error
.A
Dunham, C. B.
.K
logarithmic error, transformed rational approximation, square root
.I 1833
.T
An Ambiguity in the Description of ALGOL 60
.A
Herriot, J. G.
.K
Ising problem, zero-one sequences
.I 1834
.T
An Axiomatic Basis for Computer Programming
.W
In this paper an attempt is made to explore
the logical foundations of computer programming
by use of techniques which were first applied in the
study of geometry and have later been extended to
other branches of mathematics.  This involves the elucidation
of sets of axioms and rules of inference
which can be used in proofs of the properties of computer
programs.  Examples are given of such axioms
and rules, and a formal proof of a simple theorem is
displayed.  Finally, it is argued that important
advantages, both theoretical and practical, may
follow from a pursuance of these topics.
.A
Hoare, C. A. R.
.K
axiomatic method, theory of programming, proofs of
programs, formal language definition, programming
language design, machine-independent programming, program documentation
.I 1835
.T
The IITRAN Programming Language
.W
The IITRAN language, developed to be used
by students, and its important important features
are described. IITRAN is a procedure-oriented language
with a one-level block structure and a variety
of data types.  Several novel and powerful features
are included.  A discussion of design principles
to be followed in a student language is given.
.A
Dewar, R. B. K.
Hochsprung, R. R.
.K
languages programming languages, student programming
systems, language design, high school programs,
college courses
.I 1836
.T
A New Method for Determining Linear Precedence
Functions for Precedence Grammars
.W
The precedence relations of a precedence grammar can
be precisely described by a two-dimensional
precedence matrix.  Often the information in the matrix
can be represented more concisely by a pair of
vectors, called linear precedence functions.  A new algorithm
is presented for obtaining the linear precedence
functions when given the precedence matrix; this algorithm
is shown to possess several computational
advantages.
.A
Bell, J. R.
.K
Boolean matrices, syntax, precedence grammar context-free
parsing, transition matrix, precedence
functions
.I 1837
.T
An Algol Convolution Procedure Based on the
Fast Fourier Transform (Algorithm 345 [C6])
.A
Singleton, R. C.
.K
fast Fourier transform, complex Fourier transform,
multivariate Fourier transform, Fourier series,
harmonic analysis, spectral analysis, orthogonal polynomials,
orthogonal transformation, convolution,
auto covariance, autocorrelation, cross-correlation,
digital filtering, permutation
.I 1838
.T
Normal Curve Integral (Algorithm 304 [S15])
.A
Adams, A. G.
.K
normal curve integral, probability, special functions
.I 1839
.T
Singular Value Decomposition of a Complex
Matrix (Algorithm 358 [F1, 4,5])
.A
Businger, P. A.
Goulub, G. H.
.K
singular values, matrix decomposition,
least squares solution, pseudoinverse
.I 1840
.T
An Efficient Prime Number Generator (Algorithm 357 [A1])
.A
Singleton, R. C.
.K
prime numbers, factoring, number theory
.I 1841
.T
A Prime Number Generator Using The
Treesort Principle (Algorithm 356 [A1])
.A
Singleton, R. C.
.K
prime numbers, number theory, sorting
.I 1842
.T
An Algorithm for Generating Ising Configurations (Algorithm 355 [Z])
.A
Simoes, J. M. S.
.K
Ising problem, zero-one sequences
.I 1843
.T
The Choice of Base
.W
A digital computer is considered, whose memory
words are composed on N r-state devices plus
two sign bits (two state devices).  The choice of base
B for the internal representation of floating-point
numbers on such a computer is discussed.  It is
shown that in a certain sense B= r is best.
.A
Brown, W. S.
Richman, P. L.
.K
floating-point, accuracy, base choice, number representations
.I 1844
.T
A Modular Computer Sharing System
.W
An alternative approach to the design and organization
of a general purpose interactive multiterminal
computing system is presented.  The system organization described
is a conceptually simple arrangement
of a bank of interchangeable computers, each of which
is a memory/processor pair, that are assigned to
process terminal jobs as they arrive.  One of the computers
serves as the master or control computer
and supervises the collection and distribution of messages
from and to the remote terminals.  In the
simplest form there is a disk drive for each connected
terminal.  A crosspoint switching network allows
any such disk drive to be connected to any computer.
 Thus, while each active terminal user "occupies"
a dedicated disk drive, he may share the computer with
many other terminal users in a simple manner.
 The ratio of users to computers is dependent on both
the size and power of the machines used and the
computation requirements of the particular mix of users.
 This system organization is inherently a simpler
and therefore more reliable approach to time-sharing computers
and has the potential of a highly available
system at relatively low cost.  Economic configurations
are possible for a range of systems sizes that
span at least one order of magnitude.  Finally, problem
programs developed by remote terminal users can
be run on a dedicated batch system if compatible computers are used.
.A
Baskin, H. B.
Horowitz, E. B.
Tennison, R. D.
Rittenhouse, L. E.
.K
multiple terminal systems, terminal oriented systems,
multiple processor systems, high availability,
conversational systems, general purpose time-sharing systems,
real-time response system, modular constructed
systems, modular computer-sharing systems, graphics,
file switch, intercomputer communications, control
computer, problem computer, roll-in, roll-out
.I 1845
.T
Loader Standardization for Overlay Programs
.W
The overlay capability is described for four
of the third generation computer systems: CDC-6000,
GE-635, IBM-360, and UNIVAC-1108.  A critique of the
first three systems is based on actual experience
with a large overlaid trajectory simulation program;
a short history and description of this program
is presented.  A standardization of minimum capabilities
for loaders is recommended so that programs
which must operate under more than one computer system
may be easily converted and maintained.  A proposal
that overlay software incorporates a memory occupation
specification concept instead of the conditional
tree structure is delineated.  This concept provides
more efficient and cost-effective utilization of
the memory as well as increased flexibility in program structure.
.A
Lanzano, B. C.
.K
loader, overlay, partition, region, segmentation,
linkage, linkage editor, standardization, memory
utilization, memory occupation, tree structure,
CDC-6000, GE-635, IBM-360, UNIVAC-1108
.I 1846
.T
On Simulating Networks of Parallel Processes
in Which Simultaneous Events May Occur
.W
Some of the problems of simulating discrete
event systems, particularly computer systems, on
a conventional digital computer are dealt with.  The
systems are assumed to be described as a network
of interconnected sequential processes.  Briefly reviewed
are the common techniques used to handle such
simulations when simultaneous events do not occur, can
be ignored, or can be handled by simple priority
rules.  Following this, the problem of dealing with simultaneous
events in separate processes is introduced.
 An abstraction of this problem is developed which admits
solution for a majority of commonly encountered
problems.  The technique will either find a method of
simulating the parallel events or report that none
can be found.  In some of the latter cases it is shown
to be possible to find a solution by extending
the information available to the solution technique, but
in many cases the technique becomes computationally
unfeasible when the additional information is provided.
.A
Parnas, D. L.
.K
simulation, parallel processes, simultaneous events,
picture processing, computer system simulation
.I 1847
.T
An Algorithm for Finding a Fundamental Set of Cycles of a Graph
.W
A fast method is presented for finding a fundamental
set of cycles for an undirected finite
graph.  A spanning tree is grown and the vertices examined
in turn, unexamined vertices being stored
in a pushdown list to await examination.  One stage
in the process is to take the top element v of the
pushdown list and examine it, i.e. inspect all those
edges (v,z) of the graph for which z has not yet
been examined.  If z is already in the tree, a fundamental
cycle is added; if not, the edge (v,z) is
placed in the tree.  There is exactly one such stage
for each of the n vertices of the graph.  For large
n, the store required in creases as n^2 and the time as
n^g where g depends on the type of graph involved.
 g is bounded below by 2 and above by 3, and it is shown
that both bounds are attained.  In terms of
storage our algorithm is similar to that of Gotlieb and
Corneil and superior to that of Welch; in terms
of speed it is similar to that of Welch and superior
to that of Gotlieb and Corneil.  Testsshow our
algorithm to be remarkably efficient (g=2) on random graphs.
.A
Paton, K.
.K
fundamental cycle set, graph, algorithm, cycle, spanning tree
.I 1848
.T
The Damped Taylor's Series Method for Minimizing
a Sum of Squares and for Solving Systems of
Nonlinear Equations (Algorithm 315 [E4, C5])
.A
Silverman, G.
.K
solution of equations, least squares approximation, Newton's method
.I 1849
.T
Function Minimization (Algorithm 251 [E4])
.A
Hamilton, P. A.
Boothroyd, J.
.K
function minimization
.I 1850
.T
Generation of Permutations in Lexicographic Order (Algorithm 323 [G6])
.A
Leitch, I. M.
.K
permutations, direct lexicographic order, reverse
lexicographic order, lexicographic generation
.I 1851
.T
Generator of Spanning Trees (Algorithms 354 [H])
.A
McIlroy, M. D.
.K
spanning trees, trees, graphs
.I 1852
.T
A Base for a Mobile Programming System
.W
An algorithm for a macro processor which has
been used as the base of an implementation, by
bootstrapping, of processors for programming languages is
described.  This algorithm can be easily implemented
on contemporary computing machines.  Experience with
programming languages whose implementation is based
on this algorithm indicates that such a language can
be transferred to a new machine in less than one
man-week without using the old machine.
.A
Orgass, R. J.
Waite, W. M.
.K
bootstrapping, macro processing, machine independence,
programming languages, implementation techniques
.I 1853
.T
Compact List Representation: Definition,
Garbage Collection, and System Implementation
.W
Compact lists are stored sequentially in memory,
rather than chained with pointers.  Since
this is not always convenient, the Swym system permits
a list to be chained, compact, or any combination
of the two.  A description is given of that list representation
and the operators implemented (most are
similar to those of LISP 1.5).  The system garbage collector
attempts to make all lists compact; it relocates
and rearranges all of list storage using temporary storage.
 This unique list-compacting garbage collection
algorithm is presented in detail.  Several classes of the
macros used to implement the system are described.
 Finally, consideration is given to those design factors
essential to the success of a plex processing
system implementation.
.A
Hansen, W. J.
.K
data structure, data representation, list structure,
list representation, list, compact list, garbage
collection, relocation, storage reclamation, macro,
primitive list operations, plex processing, plex,
pointer, list processing system, LISP, free storage
.I 1854
.T
On Multiprogramming, Machine Coding, and Computer Organization
.W
The author feels that the interrupt feature
which is available in most modern computers is
a potent source of programming pitfalls and errors, and
that it therefore may heavily contribute to the
unreliability of programs making use of it.  A programming
scheme is presented which avoids the concept
of the interrupt and permits the specification of concurrent
(or pseudoconcurrent) activities in a supposedly
more perspicuous manner.  It is intended to serve as
a basis for the construction of operating systems,
which are prime examples of programs with concurrent
activities.  The scheme includes a set of basic
instructions for the generation, termination, and synchronization
of parallel processes.  A set of routines
representing these instructions and thereby simulating a
hypothetical machine organization has been implemented
and test on the IBM System/360.  Two programs using these
instructions, written in PL360, are presented.
.A
Wirth, N.
.K
multiprogramming, parallelism, interrupt, input-output,
computer organization, file handling, PL360
.I 1855
.T
A Program for the Syntactic Analysis of English Sentences
.W
A program is described which produces syntactic
analyses of English sentences with respect
to a transformational grammar.  The main features of the
analyzer are that it uses only a limited dictionary
of English words and that it pursues all analysis paths
simultaneously while processing the sentence
from left to right.  The form of representation used
for the dictionary and the grammar is indicated
and an outline account is given of the analysis procedure.
 Techniques for keeping the size of the analysis
record within reasonable limits and for avoiding the need
for dynamic application of certain transformational
rules are described.   A number of examples of output
produced by the program are given.  The output
includes timing information.
.A
Dewar, H.
Bratley, P.
.K
syntactic analysis, language processing, language
analysis, parsing, analysis procedure, recognition
procedure, English sentences, linguistics, psycholinguistics,
transformational grammar, limited dictionary,
predictive analysis
.I 1856
.T
The Teachable Language Comprehender:
A Simulation Program and Theory of Language
.W
The Teachable Language Comprehender (TLC) is
a program designed to be capable of being taught
to "comprehend" English text.  When text which the program
has not seen before is input to it, it comprehends
that text by correctly relating each (explicit or implicit)
assertion of the new text to a large memory.
 This memory is a "semantic network" representing factual
assertions about the world.  The program also
creates copies of the parts of its memory which have
been found to relate to the new text, adapting and
combining these copies to represent the meaning of the
new text.  By this means, the meaning of all text
the program successfully comprehends is encoded into
the same format as that of the memory.  In this
form it can be added into the memory.  Both factual
assertions for the memory and the capabilities for
correctly relating text to the memory's prior content
are to be taught to the program as they are needed.
 TLC presently contains a relatively small number of
examples of such assertions and capabilities, but
within the system, notations for expressing either of these
are provided.  Thus the program now corresponds
to a general process for comprehending language, and
it provides a methodology for adding the additional
information this process requires to actually comprehend
text of any particular kind.  The memory structure
and comprehension process of TLC allow new factual assertions
and capabilities for relating text to such
stored assertions to generalize automatically.  That
is, once such an assertion or capability is put
into the system, it becomes available to help comprehend
a great many other sentences in the future.
 Thus the addition of a single factual assertion or
linguistic capability will often provide a large
increment in TLC's effective knowledge of the world and
in its overall ability to comprehend text.  The
program's strategy is presented as a general theory of language comprehension.
.A
Quillian, M. R.
.K
natural language processing, natural language comprehension,
teachable computer program, psychological
simulation, human memory simulation, computer
linguistics, linguistic performance theory
.I 1857
.T
Filon Quadrature (Algorithm [D1])
.A
Chase, S. M.
Fosdick, L. D.
.K
quadrature, Filon quadrature, integration, Filon
integration, Fourier coefficients, Fourier series
.I 1858
.T
An Algorithm for Filon Quadrature
.W
An algorithm for Filon quadrature is described.
 Considerable attention has been devoted to
an analysis of the round-off and truncation errors.
 The algorithm includes an automatic error control
feature.
.A
Chase, S. M.
Fosdick, L. D.
.K
quadrature, Filon quadrature, integration, Filon
integration, Fourier coefficients, Fourier series
.I 1859
.T
Error Bounds for Periodic Quintic Splines
.W
Explicit error bounds for periodic quintic spline
interpolation are developed.  The first (third)
derivative of the periodic spline is shown to be a sixth
(fourth) order approximation at the mesh points
to the first (third) derivative of the function being interpolated.
.A
Hall, C. A.
.K
spline, interpolation, error bounds
.I 1860
.T
An Algol-Based Associative Language
.W
A high level programming language for large,
complex associative structures has been designed
and implemented.  The underlying data structure has
been implemented using a hash-coding technique.
The discussion includes a comparison with other work
and examples of applications of the language.
.A
Feldman, J. A.
.K
ALGOL, associative, programming language, data structure
.I 1861
.T
The MAD Definition Facility
.W
One of the first definition facilities for
higher level languages is described.  Users of the
language can define new operators and/or data types
into the MAD language, so that their use appears
as if they were predefined.  Information is given on
how one writes definitions, as well as on much of
the motivation behind the form in which definitions are
written. Some conclusions are drawn about future
definitional facilities.
.A
Arden, B. W.
Galler, B. A.
Graham, R. M.
.K
MAD, definitions, operators, macros, higher level language
.I 1862
.T
Computing Capabilities at Argentine and Chilean Universities
.W
The author reports on a trip to universities in
Argentina and Chile during November 1968, describing
university conditions and computing activities.  As elsewhere,
these universities are experiencing student
discontent with the status quo and the solutions they
are attempting contrast: Argentina is excluding
students from participating in university government;
Chile is allowing such participation.  University
computing service and academic activities are limited.
 The number of computers is small and so is the
capacity, none larger than an IBM 360/40; with some
exception, computing science academic programs are
rare. This situation is by no means attributable to
those responsible for computing developments, who
strive for excellence; rather the "system" is hard to
over-come.  Universities, especially those with
strong European traditions, adapt slowly to new academic
resources and disciplines; superimposed are
the severe technological and economic constraints of the
developing nation.  Consequently, in the absence
of conscious government emphasis on strengthening computing
capabilities, future progress may be retarded.
.A
Finerman, A.
.K
university education, computing science academic
programs, university computing centers, surveys
of computing centers, university computing capabilities, university-student
relationship, Argentine universities,
Chilean universities, South American universities, developing nations
.I 1863
.T
Minit Algorithm for Linear Programming (Algorithm 333 [H])
.A
Messham, D. K.
.K
linear programming, dual simplex method, primal problem, dual problem
.I 1864
.T
Generation of Hilbert Derived Test Matrix (Algorithm 274 [F1])
.A
Boothroyd, J.
.K
test matrix, Hilbert matrix
.I 1865
.T
Algol 60 Reference Language Editor (Algorithm 268 [R2])
.A
Sauer, G.
.K
symbol manipulation
.I 1866
.T
Characteristic Values and Associated Solutions
of Mathieu's Differential Equation (Algorithm
352 [S22])
.A
Clemm, D. S.
.K
Mathieu's differential equation, Mathieu function,
characteristic value, periodic solution, radial
solution
.I 1867
.T
On the Expected Lengths of Sequences Generated
in Sorting by Replacement Selecting
.W
In the replacement-selecting technique of sorting,
one is interested in the ratio L(j) of the
expected length of the j-th sequence generated by the
technique to the number of memory cells used.
Using complex-variable theory, it is shown that L(j)
-> 2 and that, asymptotically, the average interval
between sign changes of L(j)-2 is 2.6662.
.A
Hooker, W. W.
.K
replacement selecting, sorting, sequence lengths,
asymptotic expected length, recursion relation,
generating function, meromorphic function
.I 1868
.T
On Obtaining Correct Input:A New Approach
.W
Most information put into machine readable
form, whether from scientific or business origins,
is still keypunched.  This paper is addressed toward
the difficulty of obtaining correctly keypunched
and key verified data and an alternative method is suggested
in which the computer itself is used to rule
out the possibility of errors in input.  This technique
is explained and illustrated by reference to
a working program which involves essentially two phases:
in the first phase errors are detected by the
machine, and subsequently, in the second phase, they are corrected by it.
.A
Kennedy, M.
.K
correct data, correct input, data correction,
keypunch, key verifier, verifier
.I 1869
.T
Block Structures, Indirect Addressing, and Garbage Collection
.W
Programming languages have included explicit
or implicit block structures to provide a naming
convenience for the programmer.  However, when indirect
addressing is used, as in SNOBOL, naming constraints
may be introduced.  Two modifications to SNOBOL are described,
resulting in two desirable consequences:
(1) naming constraints disappear even when there is
indirect addressing within function definitions;
and (2) there is a significant saving in the number of
calls to the garbage collector, because some garbage
is collected, at little expense, each time a function
returns to its calling program.  These modifications
have been implemented as an extension to a SNOBOL dialect.
.A
Kain, R. Y.
.K
block structures, indirect addressing,
garbage collection, local names, SNOBOL
.I 1870
.T
Some Techniques for Using Pseudorandom Numbers in Computer Simulation
.W
An algorithm is described by which uniform pseudorandom
integers may be used to construct binary
"numbers" in which the probability that each bit in the
word is a 1-bit and can assume any desired parameter
value.  Techniques for making use of such "numbers"
in simulation programming are described.
.A
Donnelly, T.
.K
random numbers,  simulation, Boolean algebra, bit manipulation
.I 1871
.T
Automatic Contour Map
.W
Some methods for contour mapping by means of
a digital plotter are discussed, and a new method
is presented that is simple enough to be implemented by
programs with a rather small number of instructions
(about 120 FORTRAN IV instructions are required).  Comparisons
with some methods proposed by other authors
are also performed,  A FORTRAN IV program implementing
the proposed method is available at the Istituto
di Elettrotecnica ed Elettronica, Politencnico di Milano.
.A
Cottafava, G.
LeMoli, G.
.K
contour map, level lines, digital plotting, function scanning
.I 1872
.T
Chebyshev Interpolation and Quadrature
Formulas of Very High Degree (Errata)
.A
Salzer, H. E.
.I 1873
.T
Accelerating LP Algorithms
.W
It is shown how a novel method for computing
(related) inner products can accelerate the pricing
phase of LP algorithms.  Other LP applications are indicated.
.A
Fox, B. L.
.K
linear programming, revised simplex
method, multiple pricing, inner product
.I 1874
.T
Generating Pseudorandom Numbers on a Two's
Complement Machine such as the IBM 360
.W
The familiar multiplicative congruential generator
is examined in the context of the type of
two's complement arithmetic used in the IBM 360 series.
 Different sequences of residues are considered
and relationships established among them.  It is shown
that a sequence of positive and negative residues
may be produced more simply and economically than with
the conventional approach and yet have twice the
period of the latter without loss of desirable statistical
properties.  Another easily generated sequence
involving absolute values is also shown to have twice
the period but with less attractive statistical
properties.  The statistical properties of these sequences
are given and related to previously established
criteria.
.A
Hemmerle, W. J.
.K
random number, uniform distribution, pseudo-random
number, random number generator, multiplicative
congruential generator, power residue, two's
complement arithmetic, IBM 360 arithmetic
.I 1875
.T
Polynomial and Spline Approximation by Quadratic Programming
.W
The problem of approximation to a given function,
or of fitting a given set of data, where
the approximating function is required to have certain
of its derivations of specified sign over the
whole range of approximation, is studied.  Two approaches
are presented, in each of which quadratic programming
is used to provide both the constraints on the derivatives
and the selection of the function which yields
the best fit.  The first is a modified Bernstein polynomial
scheme, and the second is a spline fit.
.A
Amos, D. E.
Slater, M. L.
.K
constant sign derivatives, Bernstein polynomials,
linear concavity constraints, quadratic programming
splines
.I 1876
.T
Generation of Test Matrices Having Certain
Sign Patterns and Prescribed Positive Spectra
.W
A class of orthogonal transformations is presented
whose members transform a given positive
diagonal matrix into a matrix having one of four special sign patterns.
.A
Schneider, A. J.
.K
test matrices, positive matrices, sign patterns,
orthogonal transformations, positive eigenvalues
.I 1877
.T
Prevention of System Deadlocks
.W
A well-known problem in the design of operating
systems is the selection of a resource allocation
policy that will prevent deadlock.  Deadlock is the
situation in which resources have been allocated
to various tasks in such a way that none of the tasks
can continue.  The various published solutions
have been somewhat restrictive: either they do not handle
the problem in sufficient generality or they
suggest policies which will on occasion refuse a request
which could have been safely granted.  Algorithms
are presented which examine a request in the light of
the current allocation of resources and determine
whether or not the granting of the request will introduce
the possibility of a deadlock.  Proofs given
in the appendixes show that the conditions imposed by
the algorithms are both necessary and sufficient
to prevent deadlock.  The algorithms have been successfully used in the THE system.
.A
Habermann, A. N.
.K
multiprogramming, time-sharing, scheduling, resource allocation
.I 1878
.T
Recovery of Reentrant List Structures in SLIP
.W
One consequence of the reference-count-based
space-recovery system employed by SLIP is that
reentrant list structures are not recovered even when
explicitly erased.  LISP-like garbage-collection
schemes are free of this impediment.  They however,
depend on being able to find and mark nodes that
are reachable from program variables.  By tracing all
descendants from program variables may then be
identified and collected.  The list-creating function
LIST of SLIP may be amended to mark those lists
for which the programmer wishes to assume responsibility.
 Given this modification, a LISP-like garbage
collector that recovers abandoned reentrant list structures
may then be appended to the SLIP system.
.A
Weizenbaum, J.
.K
list processing, SLIP, garbage-collection
.I 1879
.T
A Note on Storage Fragmentation and Program Segmentation
.W
The main purpose of this paper is the presentation
of some of the results of a series of simulation
experiments investigating the phenomenon of storage fragmentation.
 Two different types of storage fragmentation
are distinguished: (1) external fragmentation, namely the
loss in storage utilization caused by the inability
to make use of all available storage after it has been
fragmented into a large number of separate blocks;
and (2) internal fragmentation, the loss of utilization
caused by rounding up a request for storage,
rather than allocating only the exact number of words required.
 The most striking result is the apparently
general rule that rounding up requests for storage,
to reduce the number of different sizes of blocks
coexisting in storage, causes more loss of storage
by increased internal fragmentation than is saved
by decreased external fragmentation.  Described also are
a method of segment allocation and an accompanying
technique for segment addressing which take advantage
of the above result.  Evidence is presented of
possible advantages of the method over conventional paging techniques.
.A
Randell, B.
.K
storage allocation, storage fragmentation,
paging, segmentation, addressing
.I 1880
.T
Chebyshev Solution to an Overdetermined
Linear System (Algorithm 328 [F4])
.A
Golub, G. H.
.K
Chebyshev solutions, over-determined linear
systems, linear equations, exchange algorithm
.I 1881
.T
Transpose Vector Stored Array (Algorithm 302 [K2])
.A
MacLeod, I. D. G.
.K
matrix transposition, array transposition, vector stored array
.I 1882
.T
Determination of the Square Root of a Positive
Definite Matrix (Algorithm 298 [F1])
.A
Duke, B. J.
.K
matrix, symmetric matrix, positive definite matrix, matrix square root
.I 1883
.T
Modified Romberg Quadrature(Algorithm [D1])
.A
Fair weather, G.
.K
numerical integration, Romberg quadrature,
trapezoid values, rectangle values, error bound
.I 1884
.T
An Anomaly in Space-Time Characteristics of
Certain Programs Running in a Paging Machine
.W
The running time of programs in a paging machine
generally increases as the store in which
programs are constrained to run decreases.  Experiments,
however, have revealed cases in which the reverse
is true: a decrease in the size of the store is accompanied
by a decrease in running time.  An informal
discussion of the anomalous behavior is given, and for
the case of the FIFO replacement algorithm a formal
treatment is presented.
.A
Belady, L. A.
Nelson, R. A.
Shedler, G. S.
.K
paging machines, demand paging, replacement algorithm
.I 1885
.T
A Computer System for Transformational Grammar
.W
A comprehensive system for transformational
grammar has been designed and implemented on the
IBM 360/67 computer.  The system deals with the transformational
model of syntax, along the lines of
Chomsky's Aspects of the Theory of Syntax. The major
innovations include a full,formal description of
the syntax of a transformational grammar, a directed random
phrase structure generator, a lexical insertion
algorithm, an extended definition of analysis, and
a simple problem-oriented programming language in
which the algorithm for application of transformations
can be expressed.  In this paper we present the
system as a whole, first discussing the general attitudes underlying
the development of the system, then
outlining the system and discussing its more important
special features.  References are given to papers
which consider some particular aspect of the system in detail.
.A
Friedman, J.
.K
transformational grammar, natural language syntax,
language processing, language analysis, sentence
generation, lexical insertion, computational linguistics, syntax
.I 1886
.T
Generation of Optimal Code for Expressions via Factorization
.W
Given a set of expressions which are to be
compiled, methods are presented for increasing the
efficiency of the object code produced by first factoring
the expressions, i.e. finding a set of subexpressions
each of which occurs in two or more other expressions
or subexpressions.  Once all the factors have been
ascertained, a sequencing procedure is applied which
orders the factors and expressions such that all
information is computed in the correct sequence and factors
need be retained in memory a minimal amount
of time.  An assignment algorithm is then executed in
order to minimize the total number of temporary
storage cells required to hold the results of evaluating
the factors.  In order to make these techniques
computationally feasible, heuristic procedures are
applied, and hence global optimal results are not
necessarily generated.  The factorization algorithms
are also applicable to the problem of factoring
Boolean switching expressions and of factoring polynomials
encountered in symbol manipulating systems.
.A
Breuer, M. A.
.K
factorization algorithms, code optimization, sequencing
of operations, detection of common subexpressions,
factorization of Boolean expressions
.I 1887
.T
A Recursive Relation for the Determinant of a Pentadiagonal Matrix
.W
A recursive relation, relating leading principal
minors, is developed for the determinant of
a pentadiagonal matrix.  A numerical example is included
to indicate its use in calculating eigenvalues.
.A
Sweet, R. A.
.K
pentadiagonal matrix, quindiagonal matrix, quindiagonal
matrix, band matrix, determinant, characteristic
polynomial, eigenvalues
.I 1888
.T
Spline Function Methods for Nonlinear Boundary-Value Problems
.W
The solution of the nonlinear differential equation
Y"=F(x,Y,Y') with two-point boundary conditions
is approximated by a quintic or cubic spline function
y(x).  The method is well suited to nonuniform
mesh size and dynamic mesh size allocation.  For uniform
mesh size h, the error in the quintic spline
y(x) is O(h^4), with typical error one-third that from
Numerov's method.  Requiring the differential
equation to be satisfied at the mesh points results
in a set of difference equations, which are block
tridiagonal and so are easily solved by relaxation or other standard methods.
.A
Blue, J. L.
.K
boundary value problems, differential equations,
finite differences, functional approximation,
iterative methods, nonlinear equations, spline functions
.I 1889
.T
Introducing Computing to Smaller Colleges
and Universities -- A Progress Report
.W
By technical means that are now routine, computer
service for smaller colleges and universities
can be provided by remote terminals of a central facility.
 Access, however, is not enough-effective
organizational and educational methodology for introducing
computing at such institutions must also be
developed.  The experience of two years with a statewide
network involving-41 institutions is discussed.
 Lessons include the importance of a separate organization
representing the small colleges, the necessity
for on-campus training for the institutions, the need
for some special programming and documentation
to support such users,and the development of curriculum by evolutionary means.
.A
Parker Jr., L. T.
Gallie, T. M.
Brooks Jr., F. P.
Ferrel, J. K.
.K
regional network, introducing computing, under-graduate
education, instructional usage, academic
applications, curriculum development, orientation project,
regional center, consortium, remote computing
.I 1890
.T
Simulation of Traffic Flows in a Network
.W
A computer simulation program which deals
with traffic flows in the network of a large area
is described.  Each road is segmented into blocks of
several ten-meter lengths and is represented by
a bidirectional list in computer memory.  The movement
of cars, i.e. the transfer of cars from one block
to the next, is expressed by a proper formula.  This
formula is based on the supposition that the speed
of cars in a block is determined only by the density of
cars in the block, and this speed-versus-density
curve is empirically given the numerical values.  This
simulation scheme has its excellent point in that
it makes it possible to trace the dynamic behavior
of traffic flows in a variety of situations, some
examples of which are given for an actual area of the city of Kyoto, Japan.
.A
Sakai, T.
Nagao, M.
.K
traffic simulation, traffic flow, traffic network
traffic control, traffic density, intersection,
signal setting, vehicle, road network, list structure, computer simulation
.I 1891
.T
Three-Dimensional Computer Display
.W
A stereographic display terminal has been
produced using the raster display (BRAD) recently
developed at Brookhaven.  The system uses a rotating refresh
memory to feed standard television monitors.
 To produce a stereographic display the computer calculates
the projected video images of an object,
viewed from two separate points.  The resulting video
maps are stored on separate refresh bands of the
rotating memory.  The two output signals are connected
to separate color guns of a color television monitor,
thus creating a superimposed image on the screen.  Optical
separation is achieved by viewing the image
through color filters.  The display is interactive and
can be viewed by a large group of people at the
same time.
.A
Ophir, D.
Shepherd, B. J.
Spinrad, R. J.
.K
computer graphics, three-dimensional display, swept
raster display, interactive stereographic terminal,
video map, color separation
.I 1892
.T
Degree of Multiprogramming in Page-on-Demand Systems
.W
A simple stochastic model is described which
offers a base for understanding the relationship
between the number of programs permitted to share memory
(the degree of multiprogramming), drum traffic
rates, and central processing unit utilization in page-on-demand,
multiprogrammed, time-shared computer
systems.  The model preserves, as a key feature, the
property of page-demand statistics which implies
a "burst" of page demands at the beginning of any job
or quantum execution.  The model, a Markov chain,
is analyzed numerically and the results are presented graphically
for a wide range of key environment-descriptive
parameters.  Implications of the results to time-shared
system design and programming are discussed,
and a calculation of the optimal degree of multiprogramming
for a wide range of parameters is presented
graphically.
.A
Wallace, V. L.
Mason, D. L.
.K
page-on-demand, demand paging, time-sharing multiprogramming,
Markovian computer models, scheduling
strategies, operating systems, memory management
.I 1893
.T
Roots of Polynomials by a Root-Squaring
and Resultant routine (Algorithm 340 [C2])
.A
Noltemeier, A.
.K
root finders, roots of polynomial equations, polynomial
zeros, root-squaring operations, Graeffe
method, resultant procedure, subresultant procedure,
testing of roots, acceptance criteria
.I 1894
.T
Normal Random Deviates (Algorithm 334 [G5])
.A
Knop, R.
.K
normal deviates, normal distribution, random number,
random number generator, simulation, probability
distribution, frequency distribution, random
.I 1895
.T
Gaussian Quadrature Formulas (Algorithm 331 [D1])
.A
Hill, I. D.
.K
quadrature, Gaussian quadrature, numerical integration,
weight function, orthogonal polynomials
.I 1896
.T
Regular Coulomb Wave Functions (Algorithm 292 S22])
.A
Gautschi, W.
.K
Coulomb wave functions, wave functions, regular Coulomb wave functions
.I 1897
.T
Coulomb Wave Functions (Algorithm 300 [S22])
.A
Kolbig, K. S.
.K
Coulomb wave functions, wave functions
.I 1898
.T
Regular Coulomb Wave Functions (Algorithm 292 [S22])
.A
Kolbig, K. S.
.K
Coulomb wave functions, wave functions, regular Coulomb wave functions
.I 1899
.T
Simplex Method Procedure Employing Lu Decomposition (Algorithm 350 [H])
.A
Bartels, R. H.
Golub, G. H.
.K
simplex method, linear programming, LU decomposition,
round-off errors, computational stability
.I 1900
.T
Clarification of Fortran Standards-Initial Progress
.W
In 1966 after four years of effort, FORTRAN
became the first programming language standardized
in the United States.  Since that initial achievement,
study and application of the standard specifications
have revealed the need for maintenance of the standards.
 As the result of work initiated in 1967, an
initial set of clarifying interpretations has been prepared.
 The nature of the maintenance, corrections
to the standard specifications, and completed interpretations are reported.
.K
USA Standard, FORTRAN, Basic FORTRAN, programming
language, standardization, language standard
specification, language standard maintenance, language standard
clarification, language standard interpretation,
standardization committee
.I 1901
.T
Dynamic Space-Sharing in Computer Systems
.W
A formalization of relationships between space-shading
program behavior, and processor efficiency
in computer systems is presented.  Concepts of value and
cost of space allocation per task are defined
and then value and cost are combined to develop a single
parameter termed value per unit cost.  The intent
is to illustrate a possible analytic approach to the
investigation of the problems of space-sharing and
to demonstrate the method on sample problems.
.A
Belady, L. A.
Kuehner, C. J.
.K
space-sharing, storage allocation, memory allocation,
storage management, memory management, program
behavior, multiprogramming, computer system design, allocation
strategies, replacement strategies, demand-paging,
time-sharing
.I 1902
.T
An Automatic Grading Scheme for Simple Programming Exercises
.W
A discussion is given of alterations that were
made to a typical university operating system
to record the results of programming exercises in three
different languages, including assembly language.
 In this computer-controlled grading scheme provision
is made for testing with programmer-supplied data
and for final runs with system-supplied data.  Exercises
run under the scheme may be mixed with other
programs, and no special recognition of exercises by the operators is necessary.
.A
Hext, J. B.
Winings, J. W.
.K
automatic grading program, programming exercises
.I 1903
.T
Chebyshev Interpolation and Quadrature Formulas of Very High Degree
.A
Salzer, H. E.
.K
Chebyshev polynomials, Chebyshev interpolation,
Chebyshev quadrature, Chebyshev points, Chebyshev
zeros, interpolation, quadrature, definite integrals
.I 1904
.T
Rough and Ready Error Estimates in Gaussian
Integration of Analytic Functions
.A
Rabinowitz, P.
.K
numerical integration, analytic functions, error
estimates, Gaussian integration, tabulated error
coefficients, computable error coefficients, Cauchy
integral formula, Chebyshev polynomials
.I 1905
.T
The Simplex Method of Linear Programming Using LU Decomposition
.W
Standard computer implementations of Dantzig's
simplex method for linear programming are based
upon forming the inverse of the basic matrix and updating
the inverse after every step of the method.
 These implementations have bad round-off error properties.
 This paper gives the theoretical background
for an implementation which is based upon the LU decomposition,
computed with row interchanges, of the
basic matrix.  The implementation is slow, but has good
round-off error behavior.  The implementation
appears as CACM Algorithm 350.
.A
Bartels, R. H.
Goulub, G. H.
.K
simplex method, linear programming, LU decomposition,
round-off errors, computational stability
.I 1906
.T
Automated Printed Circuit Routing with a Stepping Aperture
.W
A computer program for routing interconnections
on a two-sided printed circuit board with a
regular pattern of lines, pins (terminals), and vias
(feed-through holes) is described.  In this program,
each interconnection is given a planned routing-typically,
down from the upper pin, through a via, and
horizontally to the lower pin.  From the top, a virtual
aperture (i.e. a long horizontal slit) is stepped
down the board.  The planned routing is the basis for
rerouting interconnections within the aperture
to resolve conflicts for lines and vias below the aperture
and to maximize the effective line usage.
 If a conflict has not been resolved before the aperture
arrives at the lower pin,interconnections are
deleted to resolve the conflict.  Extensions of this technique
to the control of crosstalk between routed
interconnections and to the problem of obtaining
100 percent interconnect are also discussed.
.A
Lass, S.E.
.K
routing, printed circuit, interconnections, aperture,
stepping aperture, computer program, circuit
board, lines, vias, pins
.I 1907
.T
A Note on Reliable Full-Duplex Transmission over Half-Duplex Links
.W
A simple procedure for achieving reliable full-duplex
transmission over half-duplex links is
proposed. The scheme is compared with another of the
same type, which has recently been described in
the literature.  Finally, some comments are made on
another group of related transmission procedures
which have been shown to be unreliable under some circumstances.
.A
Bartlett, K. A.
Scantlebury, R. A.
.K
data transmission, error correction, full-duplex,
half-duplex, transmission control, communications
.I 1908
.T
Time-Sharing and Batch-Processing:  An Experimental
Comparison of Their Values in a Problem -
Solving Situation
.W
An experimental comparison of problem-solving
using time-sharing and batch-processing computer
systems conducted at MIT is described in this paper.
 This study is the first known attempt to evaluate
two such systems for what may well be the predominant user
population within the next decade-the professionals
who, as nonprogrammers, are using the computer as an
aid in decision-making and problem-solving rather
than as a programming end in itself.  Statistically
and logically significant results indicate equal
cost for usage of the two computer systems; however,
a much higher level of performance is attained by
time-sharing users.  There are indications that significantly
lower costs would have resulted if the
time-sharing users had stopped work when they reached
a performance level equal to that of the batch
users.  The users' speed of problem-solving and their
attitudes made time-sharing the more favorable
system.
.A
Gold, M. M.
.K
time-sharing vs batch-processing, user performance,
man/machine communications, cost effectiveness,
on-line vs off-line performance, decision-making performance,
user/programmer behavior, programming experimental
empirical studies, problem-solving, research in man/machine
communications, man/machine symbiosis
.I 1909
.T
Computation of Jn(x) by Numerical Integration
.W
It is shown to be practical to compute Jn(x) by
numerical integration of its integral representation
using the trapezoidal rule. The error in this
approximation was studied empirically.
.A
Stroud, A. H.
Kohli, J. P.
.K
Bessel Function, numerical integration, trapezoidal rule
.I 1910
.T
An Algorithm for Solving a Special Class
of Tridiagonal Systems of Linear Equations
.W
An algorithm is presented for solving a system
of linear equation Bu=k where B is tridiagonal
and of a special form.  It is shown that this algorithm
is almost twice as fast as the Gaussian elimination
method usually suggested for solving such systems.
In addition, explicit formulas for the inverse and
determinant of the matrix B are given.
.A
Rose, D. J.
.K
tridiagonal, Gaussian elimination, central difference
.I 1911
.T
On Coordination Reduction and Sentence Analysis
.W
A class of coordination phenomena in natural
languages is considered within the frame work
of transformational theory.  To account for these phenomena
it is proposed that certain machinery be
added to the syntactic component of a transformational
grammar. This machinery includes certain rule
schemata, the conditions under which they are to be
applied, and conditions determining the sequence
of subtrees on which they are to be performed.  A solution
to the syntactic analysis problem for this
class of grammars is outlined.  Precise specification
of both the generative procedure of this paper
and its inverse is given in the form of LISP function definitions.
.A
Petrick, S. R.
Postal, P. M.
Rosenbaum, P. S.
.K
natural languages, generative grammar, transformational
theory, syntax, coordination, sentence
coordination, sentence coordination, coordination reduction,
syntactic analysis, grammar testing program,
rule testing
.I 1912
.T
Simulation of Outpatient Appointment Systems
.W
An experimental computer program is described
which simulates appointment systems employed
by outpatient departments of hospitals.  Both major kinds
of appointment systems-individual and block-can
be simulated.  The purpose of the Simulator is to enable
the user to evaluate the effectiveness of alternative
appointment systems in a given clinical environment.
.A
Katz, J. H.
.K
simulation, scheduling, appointment system, outpatient
department, medicine, health, management
science, operations research
.I 1913
.T
Polygamma Functions with Arbitrary Precision (Algorithm 349 [S14])
.A
Schwachheim, G.
.K
polygamma function, psi function, digamma function,
trigamma function, tetragamma function, pentagamma
function, special functions
.I 1914
.T
Matrix Scaling by Integer Programming (Algorithm 348 [F1])
.A
Klimpel, R. R.
.K
integer programming, linear algebra, mathematical
programming, matrix condition, matrix scaling
.I 1915
.T
An Algorithm for Hidden Line Elimination
.W
The algorithm presented causes the elimination of
hidden lines in the representation of a perspective
view of concave and convex plane-faced objects on the
picture plane.  All the edges of the objects are
considered sequentially, and all planes which hide every
point of an edge are found.  The computing time
increases roughly as the square of the number of edges.
 The algorithm takes advantage of a reduced number
of concave points and automatically recognizes if only
one object with no concave points is considered.
In this last case, the result is obtained in a much simpler way.
.A
Galimberti, R.
Montanari, U.
.K
hidden line elimination, back line recognition, three-dimensional
representation, plane-faced objects,
perspective view, machine rendering of solids, automatic
drawing, displaying techniques, computer graphics,
man/machine interaction, man/machine communication, computer-aided design
.I 1916
.T
Analysis of Boolean Program Models for Time-Shared, Paged Environments
.W
Directed graphs or their associated matrices are
frequently used to represent the logical structure
of sequences of computer instructions.  Such techniques
are used and, in addition, data references are
represented in a nondirected model. The complete structural
specification of a program is represented
by a combined model.  A transformation of the combined
model yields a new model in which additional timing
information is also contained.  Analysis of these models
prior to execution yields information valuable
in determining segmentation of instructions and data for
a time-shared environment, as well as for initial
page loading; during execution, the analysis may be
used for "look ahead" control of page turning.
.A
Lowe, T. C.
.K
time-sharing, paging, segmentation, executive,
compiler, monitor, program model
.I 1917
.T
An Algol Procedure for the Fast Fourier Transform
with Arbitrary Factors (Algorithm 339 [C6])
.A
Singleton, R. C.
.K
fast Fourier transform, complex Fourier transform,
multivariate Fourier transform, Fourier series,
harmonic analysis, spectral analysis, orthogonal polynomials,
orthogonal transformation, virtual core
memory, permutation
.I 1918
.T
Distribution of Indistinguishable Objects
into Distinguishable Slots (Algorithm 329 [G6])
.A
Gray, M.
.I 1919
.T
An Efficient Algorithm for Sorting with
Minimal Storage (Algorithm 347 [M1])
.A
Singleton, R. C.
.K
sorting, minimal storage sorting, digital computer sorting
.I 1920
.T
F-Test Probabilities (Algorithm 346 [S14])
.A
Morris, J.
.K
F-test, Snedecor F-statistic, Fisher Test, distribution function
.I 1921
.T
An Algol Convolution Procedure Based on the
Fast Fourier Transform (Algorithm 345 [C6])
.A
Singleton, R. C.
.K
fast Fourier transform, complex Fourier transform,
multivariate Fourier transform, Fourier series,
harmonic analysis, spectral analysis, orthogonal polynomials,
orthogonal transformation, convolution,
auto covariance, autocorrelation, cross-correlation,
digital filtering, permutation
.I 1922
.T
Proposed USA Standard (Data Communication Control
Procedures for the USA Standarad Code for Information
Interchange)
.K
data communication, data communication control procedures,
data communication establishment/termination
procedures, data communication message transfer procedures,
data communication error control procedures,
data communication polling/selection procedures, communication,
communication control procedures, communication
establishment/termination procedures, communication
message transfer procedures, communication error
control procedures, communication polling/selection procedures,
link, link control procedures, link establishment/termination
procedures, link message transfer procedures, link error
control procedures, link polling/selection procedures,
data link, data link control procedures, data link  establishment/termination
procedures, data link message
transfer procedures, data link error control procedures,
data link polling/selection procedures
.I 1923
.T
Pseudofiles
.W
An approach to system interfaces for high
level languages using basic input/output support
facilities is described.  It is shown that this technique
can provide potentially inexpensive methods
for programs to communicate with deeply embedded
facilities such as command language processors.
.A
Rosin, R. F.
.K
operating systems, interfaces input-output,
high level languages, command language
.I 1924
.T
Organizing Matrices and Matrix Operations for Paged Memory Systems
.W
Matrix representations and operations are examined
for the purpose of minimizing the page faulting
occurring in a paged memory system.  It is shown that
carefully designed matrix algorithms can lead to
enormous savings in the number of page faults occurring
when only a small part of the total matrix can
be in main memory at one time.  Examination of addition,
multiplication, and inversion algorithms shows
that a partitioned matrix representation (i.e. one submatrix
or partition per page) in most cases induced
fewer page faults than a row-by-row representation.
 The number of page-pulls required by these matrix
manipulation algorithms is also studied as a function
of the number of pages of main memory available
to the algorithm.
.A
McKellar, A. C.
Coffman Jr., E. G.
.K
matrix algorithms, array processing, paging algorithms,
paged memory systems, virtual memory systems,
array storage allocation, storage allocation
.I 1925
.T
Concepts of Use in Contour Map Processing
.W
Generalized techniques whose use can simplify
the solution of problems relating to contour
maps.  One of these techniques makes use of the topological
properties of contour maps.  The topology
is represented by a graphical structure in which adjacent
contour lines appear as connected nodes.  Another
generalized technique consists of utilizing geometrical
properties to determine the characteristics of
straight lines drawn on the contour map.  Both of these
techniques have been applied to the problem of
locating the ground track of an aircraft from
elevation readings obtained during a flight.
.A
Morse, S. P.
.K
map, contour map, contour lines, topological properties,
geometrical properties, graph of contour
map, navigation
.I 1926
.T
Description of FORMAT, a Text-Processing Program
.W
FORMAT is a production program which facilitates
the editing and printing of "finished" documents
directly on the printer of a relatively small (64k) computer
system.  It features good performance, totally
free-form input, very flexible formatting capabilities
including up to eight columns per page, automatic
capitalization, aids for index construction, and a
minimum of nontext items.  It is written entirely
in FORTRAN IV.
.A
Berns, G. M.
.K
text processing, indexing, printing, documentation,
text editing, formatting, frequency dictionary,
right justification, vocabulary
.I 1927
.T
Information Science in a Ph.D. Computer Science Program
.W
This report contains recommendations on a sample course
curriculum in the general area of information
organization and information system design in a Ph.D.
Computer Science Program.  The subject area is
first briefly described, followed by a listing of some desirable
graduate-level courses.  Suitable bibliographies
are appended.
.A
Salton, G.
.K
course curriculum, graduate courses, university
courses,computer science curriculum, information
science, information organization, information retrieval,
data retrieval, language analysis, information
processing
.I 1928
.T
Exclusive Simulation of Activity in Digital Networks
.W
A technique for simulating the detailed logic
networks of large and active digital systems
is described.  Essential objectives sought are improved
ease and economy in model generation, economy
in execution time and space, and a facility for handling
simultaneous activities.  The main results obtained
are a clear and useful separation of structural and behavioral
model description, a reduction of manual
tasks in converting Boolean logic into a structural model,
the elimination of manual processes in achieving
exclusive simulation of activity, an event-scheduling
technique which does not deteriorate in economy
as the event queue grows in length, and a simulation
procedure which deals effectively with any mixture
of serial and simultaneous activities.  The passage of
time is simulated in a precise, quantitative fashion
and systems to be simulated may be combinations of synchronous
and asynchronous logic.  Certain aspects
of the techniques described may be used for the simulation
of network structures other than digital networks.
.A
Ulrich, E. G.
.K
simulation, logical simulation, digital simulation,
large systems simulation, network structures,
scheduling, queuing, simultaneous activities, parallel events
.I 1929
.T
Images from Computers and Microfilm Plotters
.W
Digital computers are widely used for the
processing of information and data of all kinds,
including the pictorial information contained in photographs
and other graphical representations.  Efficient
conversion facilities for putting graphical information
into the computer and retrieving it in graphical
form are therefore much needed.  One of the most commonly
employed devices for obtaining permanent graphical
output from digital computers is the microfilm plotter.
 Regrettably, present models have no provision
for producing images with a continuous gray scale or "half tones."
 In this note several programming techniques
are described for obtaining half tone pictures from a
microfilm plotter under the control of a digital
computer.  Illustrative examples of several methods are given.
.A
Schroeder, M. R.
.K
computer images, half tone pictures, microfilm plotters; processing
.I 1930
.T
Extremely Portable Random Number Generator
.W
Extremely portable subroutines are sometimes
needed for which moderate quality and efficiency
suffice.  Typically, this occurs for library functions
(like random number generation and in core sorting)
which are not entirely universal or are not used in a
standardized way.  The literature on random number
generators does not seem to contain an algorithm that
meets requirements of this sort.  An extremely
portable 8-line FORTRAN program is provided which based
on an important paper by Coveyou and MacPherson
(1967).Using their methods, Fourier analysis is applied
to the probability function for the consecutive
n-tuples provided by our generator (with n less than
or equal to 4).  While the small modulus which must
be used to maintain portability prevents the quality
of the generator from being high, the generator
compares well with the bounds established in the above mentioned paper.
.A
Kruskal, J. B.
.K
random number generators, random numbers, random
number analysis, random generators, linear sequential
generators, random number program, pseudo random numbers
.I 1931
.T
Interval Arithmetic Determinant Evaluation
and Its Use in Testing for a Chebyshev System
.W
Two recent papers, one by Hansen and one by
Hansen and R. R. Smith, have shown how Interval
Arithmetic (I.A.) can be used effectively to bound errors
in matrix computations.  In the present paper
a method proposed by Hasen and R. R. Smith is compared
with straightforward use of I.A. in determinant
evaluation.  Computational results show the accuracy
and running times that can be expected when using
I.A. for determinant evaluation.  An application using
I.A. determinants in a program to test a set of
functions to see if they form a Chebyshev system is then presented.
.A
Smith, L. B.
.K
interval arithmetic, range arithmetic, error bounds,
determinant evaluation, Chebyshev system,
mathematical proof by computer
.I 1932
.T
The Logarithmic Error and Newton's Method for the Square Root
.W
The problem of obtaining optimal starting values
for the calculation of the square root using
Newton's method is considered.  It has been pointed out
elsewhere that if relative error is used as the
measure of goodness of fit, optimal results are not
obtained when the initial approximation is a best
fit.  It is shown here that if, instead, the so-called
logarithmic error is used, then a best initial
fit is optimal for both types of error.  Moreover, use
of the logarithmic error appears to simplify the
problem of determining the optimal initial approximation.
.A
King, R. F.
Phillips, D. L.
.K
square root, Newton's method, relative error, logarithmic
error, best fit, optimal approximation,
maximal error, recurrence relation, integer root, error curve
.I 1933
.T
Coding the Lehmer Pseudo-random Number Generator
.W
An algorithm and coding technique is presented
for quick evaluation of the Lehmer pseudo-random
number generator modulo 2**31 - 1, a prime Mersenne
number with produces 2**31 - 2 numbers, on a p-bit
(greater than 31) computer.  The computation method is
extendible to limited problems in modular arithmetic.
 Prime factorization for 2**61 - 2 and a primitive root
for 2**61 - 1, the next largest prime Mersenne
number, are given for possible construction of a pseudo-random
number generator of increased cycle length.
.A
Payne, W. H.
Rabung, J. R.
Bogyo, T. P.
.K
pseudo-random number, random number, modular arithmetic,
uniform probability density, uniform frequency
function, simulation, prime factorization, primitive roots
.I 1934
.T
On Arithmetic Expressions and Trees
.W
A description is given of how a tree representing the
evaluation of an arithmetic expression
can be drawn in such a way that the number of accumulators
needed for the computation can be represented
in a straightforward manner.  This representation reduces
the choice of the best order of computation
to a specific problem under the theory of graphs.
 An algorithm to solve this problem is presented.
.A
Redziejowski, R. R.
.K
arithmetic expression, compiler design, graph theory,
programming, storage minimization, topological
ordering,tree
.I 1935
.T
Randomized Binary Search Technique
.W
A mathematical model is developed for the mean
and variance of the number of trials to recover
a given document in a randomly received list of files.
 The search method described is binary in nature
and offers new potential for information retrieval systems.
.A
Arora, S. R.
Dent, W. T.
.K
binary pattern, file examination, graph theory, information
retrieval, mathematical model, partitioning,
probabilistic method, random sequencing, search techniques, tree structures
.I 1936
.T
Variable Length Tree Structures Having Minimum Average Search Time
.W
Sussenguth suggests in a paper (1963) that a
file should be organized as a doubly-chained tree
structure if it is necessary both to search and to update
frequently.  Such a structure provides a compromise
between the fast search/slow update characteristics of
binary searching and the slow search/fast update
characteristics of serial searching.  His method, however,
contains the limiting restriction that all
terminal nodes lie on the same level of the tree.  This paper
considers the effect of relaxing this restriction.
 First, trees which have the property that a priori the
filial set of each node is well defined are studied.
 It is proved that coding the nodes within each filial
set with respect to the number of terminal nodes
reachable from each is necessary and sufficient to guarantee
minimum average search time.  Then the more
general case (that is, where the entire structure of
the tree is changeable) is treated.  A procedure
is developed for constructing a tree with a minimum
average search time.  A simple closed expression
for this minimum average search time is obtained as
a function of the number of terminal nodes.  The
storage capacity required to implement the doubly-chained
tree structure on a digital computer is also
determined.  Finally, the total cost of the structure,
using Sussenguth's cost criterion, is computed.
 It is shown that significant improvements in both
the average search time and the total cost can be
obtained by relaxing Sussenguth's restriction that all
terminal nodes lie on the same level of the tree.
.A
Patt, Y. N.
.K
information retrieval, file searching, tree structures, double chaining
.I 1937
.T
CODAS: A Data Display System
.W
CODAS, a Customer Oriented Data System, is
a user-oriented data retrieval and display system.
 The command language of the system provides the user
with an easy means for specifying data retrieval
and display requests.  Data is displayed as tables and
graphs produced in a format ready for publication.
 In this paper the statements of the request language
and the general system design are described.
.A
Day, R. H.
Mansfield, M. K.
Ellis, M. E.
.K
data display, information retrieval, graphic display,
command languages, report program generation,
management data processing
.I 1938
.T
Some Criteria for Time-Sharing System Performance
.W
Time-sharing systems, as defined in this article,
are those multiaccess systems which permit
a terminal user to utilize essentially the full resources
of the system while sharing its time with other
terminal users.  It is each terminal user's ability
to utilize the full resources of the system that
makes quantitative evaluation of time-sharing systems
particularly difficult.  Six criteria are described
which have been successfully used to perform first-level
quantitative time-sharing system performance
evaluation.
.A
Stimler, S.
.K
time-sharing performance criteria, time-sharing
system operation, time-sharing performance analysis
.I 1939
.T
Directed Random Generation of Sentences
.W
The problem of producing sentences of a transformational
grammar by using a random generator
to create phrase structure trees for input to the lexical
insertion and transformational phases is discussed.
 A purely random generator will produce base trees
which will be blocked by the transformations, and
which are frequently too long to be of practical interest.
 A solution is offered in the form of a computer
program which allows the user to constrain and direct
the generation by the simple but powerful device
of restricted subtrees.  The program is a directed
random generator which accepts as input a subtree
with restrictions and produces around it a tree which
satisfies the restrictions and is ready for the
next phase of the grammar.  The underlying linguistic
model is that at Noam Chomsky, as presented in
Aspects of the Theory of Syntax.  The program is written
in FORTRAN IV for the IBM 360/67 and is part
of a unified computer system for transformational grammar.
 It is currently being used with several partial
grammars of English.
.A
Friedman, J.
.K
transformational grammar, natural language syntax, language
processing, sentence generation, computational
linguistics, syntax
.I 1940
.T
Calculation of a Polynomial and its Derivative
Values by Horner Scheme (Algorithm 337 [C1])
.A
Smith, O. K.
.K
function, evaluation, polynomial evaluation,
ALGOL procedure, Horner's scheme
.I 1941
.T
F-Distribution (Algorithm 322 [S14])
.A
Field, J. B. F.
.K
Fisher's F-distribution, Students's t-distribution
.I 1942
.T
Finding a Solution of N Functional Equations
in N Unknowns (Algorithm 314 [C5])
.A
Vandergraft, J.
Mesztenyi, C.
.K
functional equations, interpolation, nonlinear equations, secant method
.I 1943
.T
Complete Elliptic Integrals (Algorithm 165 [S21])
.A
Farkas, I.
.K
special functions, complete elliptic integral
of the first kind, complete elliptic integral of
the second kind
.I 1944
.T
Student's t-Distribution (Algorithm 344 [S14])
.A
Levine, D. A.
.K
Student's t-Distribution, t-test, small-sample
statistics, distribution function
.I 1945
.T
The Role of Programming in a Ph.D. Computer Science Program
.W
In this general paper the role of programming
in advanced graduate training is discussed.
Subject matter related to programming as well as programming
per se is considered.  The  importance and
application of formalism are considered and also the
need for good empirical experimentation.  A brief
outline for a sequence of courses is included, and subject
headings that have been obtained from an extensive
bibliography are given.  A bibliography of programming references is included.
.A
Arden, B. W.
.K
graduate-level programming, graduate programs, course
content, course sequence, graduate curriculum,
programming research topics, programming bibliography
.I 1946
.T
Computing Polynomial Resultants: Bezout's Determinant
vs. Collins' Reduced P.R.S. Algorithm
.W
Algorithms for computing the resultant of two
polynomials in several variables, a key repetitive
step of computation in solving systems of polynomial
equations by elimination, are studied.  Determining
the best algorithm for computer implementation depends
upon the extent to which extraneous factors are
introduced, the extent of propagation of errors caused by
truncation of real coefficients, memory requirements,
and computing speed.  Preliminary considerations narrow
the choice of the best algorithm to Bezout's
determinant and Collins' reduced polynomial remainder sequence
(p.r.s.) algorithm.  Detailed tests performed
on sample problems conclusively show that Bezout's determinant
is superior in all respects except for
univariate polynomials, in which case Collins' reduced
p.r.s. algorithm is somewhat faster.  In particular
Bezout's determinant proves to be strikingly superior in
numerical accuracy, displaying excellent stability
with regard to round-off errors. Results of tests are reported in detail.
.A
Ku, S. Y.
Adler, R. J.
.K
resultant algorithm, g.c.d. algorithm, polynomial
resultant, elimination, Bezout's determinant,
Sylvester's determinant, reduced p.r.s. algorithm, Euclidean
algorithm, multivariate polynomial equations
.I 1947
.T
Object code Optimization
.W
Methods of analyzing the control flow and data
flow of programs during compilation are applied
to transforming the program to improve object time efficiency.
 Dominance relationships, indicating which
statements are necessarily executed before others, are
used to do global common expression elimination
and loop identification.  Implementation of these and other
optimizations in OS/360 FORTRAN H are described.
.A
Lowry, E. S.
Medlock, C. W.
.K
compilers, data flow analysis, dominance, efficiency,
FORTRAN,  graph theory, loop structure, machine
instructions, object code, optimization, redundancy
elimination, register assignment, System/360
.I 1948
.T
Computers in Group Theory: a Survey
.W
Computers are being applied to an increasingly
diverse range of problems in group theory.
The most important areas of application at present are
coset enumeration, subgroup lattices, automorphism
groups of finite groups, character tables, and commutator
calculus.  Group theory programs range from
simple combinatorial or numerical programs to large
symbol manipulation systems.  In this survey the
more important algorithms in use are described and contrasted,
and results which have been obtained using
existing programs are indicated.  An extensive bibliography is included.
.A
Cannon, J. J.
.K
group theory, coset enumeration, subgroup lattices,
automorphism groups, character tables, commutator
calculus, topology, crystallography, permutation groups,
Abelian groups, discrete mathematics, non-numerical
programming, symbol manipulation, survey
.I 1949
.T
Finiteness Assumptions and Intellectual Isolation of Computer Scientists
.A
Wagner, R. A.
.K
Algol vs. Fortran, finiteness assumptions, intellectual isolation,
integer variable range, memory finiteness, finite word size
.I 1950
.T
Efficient Handling of Binary Data
.A
Raduchel, W. J.
.K
binary variables, dummy variables, bit strings, cross-tabulations
.I 1951
.T
Estimates of Distributions of Random Variables
for Certain Computer Communications Traffic Models
.W
A study of multiaccess computer communications has
characterized the distributions underlying an elementary
 model of the user-computer interactive process.  The model used is
elementary in the sense that many of the random variables that
generally are of interest in computer communications studies can be
decomposed into the elements of this model.  Data were examined
from four operational multiaccess systems, and the model is shown to
be robust; that is each of the variables of the model has the
same distribution independent of which of the four systems is being examined.
It is shown that the gamma distribution can be used to
describe the discrete variables.  Approximations to the gamma distribution
by the exponential distribution are discussed for the systems studied.
.A
Fuchs, E.
Jackson, P. E.
.K
computer communications, time-sharing,
operating systems, optimization models
.I 1952
.T
Index by Subject to Algorithms, 1970
.I 1953
.T
Exponential Integral Ei(x) (Algorithms 385 $S13))
.A
Redish, K. A.
.K
ANSI Fortran standard
.I 1954
.T
Eigenvalues and Eigenvectors of a Real
Symmetric Matrix (Algorithm 384 $F2))
.A
Stewart, G. W.
.K
real symmetric matrix, eigenvalues, eigenvectors, QR algorithm
.I 1955
.T
Characteristic Values and Associated Solutions of
Mathieu's Differential Equation (Algorithm 352 $S22))
.A
Sale, A. H. J.
.K
Mathieu's differential equation, Mathieu function, characteristic
value, periodic solution, radial solution
.I 1956
.T
Optimum Merging from Mass Storage
.W
An algorithm is displayed which yields the merge orders such that the total
read time, defined to be the sum of seek time plus data-transfer
time, is minimized for a sort using mass storage. The analysis is
parameterized in terms of the ratio of seek time to the time it takes
to fill available core with records, and the file size in units
of core lengths; and thus it can be applied to any conventional
CPU/mass storage combination.  An explicit formula for total read
time is derived, in terms of the parameters, which correlates very
well with the total read time calculated using the optimum merge
orders yielded by the algorithm.  The formula involves the roots of a simple
transcendental equation.  A short table of these roots
is included.  Numerical results are graphically displayed for a wide
range of the parameters.  It is found that the normalized read
time for optimum merging on a given hardware configuration is proportional
to the file length times the logarithm of the file length.
.A
Black, N. A.
.K
sorting, merging, optimum merging, mass storage,
sort timing, drum-merging, access time
.I 1957
.T
The List Set Generator: A Construct for Evaluating Set Expressions
.W
The list set generator is defined and algorithms
for its use are given.  The list set generator is
a construct which may be added to a list processing system or any
system that handles sets.  It efficiently generates the set which
results from any expression involving sets and set operators.  The
efficiency derives from evaluating the expression as a whole and
in parallel, rather than evaluating subexpressions and
then using those sets to arrive at the final result.
.A
Shapiro, S. C.
.K
set manipulating, list processing, set
generation, sets, lists, file processing
.I 1958
.T
Improving Round-off in Runge-Kutta Computations with Gill's Method
.W
A Runge-Kutta-Gill scheme in common use is based on an incomplete
adaptation for floating point operations of Gill's method.  An
improved version reduces round-off error significantly.  In this note
the heart of the scheme is presented in Fortran language.  It is
then shown how an improved version of the method can be obtained with
the addition of two Fortran statements.  The two version is a
significant improvement.  A numerical example comparing the two is included.
.A
Thompson, R. J.
.K
Runge-Kutta methods, ordinary differential
equations, round-off error, error analysis
.I 1959
.T
An Interrupt Based Organization for Management Information Systems
.W
A programming structure, language constructs, and a supervisory system
organization are proposed
for the design and coding of large shared data base systems.  The
bases for this organization are a generalized interrupt structure
and the newly introduced concept of "file tagging," which is the
process of associating program structures and interrupt generating
conditions with items in the data base.  An algorithm for resolving
conflicts which arise in scheduling the interrupt processing routines
is presented.  DPL, a programming language and supervisory
system in which these concepts are implemented, is used to illustrated
the new organization which is proposed for management information systems.
.A
Morgan, H. L.
.K
management information systems, integrated data processing,
supervisors, interrupts monitoring systems, supervisory
systems, interrupt scheduling, parallel processing
.I 1960
.T
Process Management and Resource Sharing in the Multiaccess System ESOPE
.W
The main design principles of the multiaccess system ESOPE are described.
Emphasis is placed on basic ideas underlying the design rather
than on implementation details.  The main features of the system
include the ability given to any user to schedule his own parallel
processes using system primitive operations, the file-memory relationship,
and the allocation-scheduling policy, which dynamically
takes into account recent information about user behavior.
.A
Betourne, C.
Boulenger, J.
Ferrie, J.
Kaiser, C.
Krakowiak, S.
Mossiere, J.
.K
time-sharing, multiprogramming, process scheduling, resource allocation
.I 1961
.T
An Efficient Search Algorithm to Find the Elementary Circuits of a Graph
.W
A theoretically most efficient search algorithm is presented
which uses an exhaustive search to find all of the elementary
circuits of a graph.  The algorithm can be easily modified to find all
of the elementary circuits with a particular attribute such as
length.  A rigorous proof of the algorithm is given as well as an example
of its application.  Empirical bounds are presented relating
the speed of the algorithm to the number of vertices and the number
of arcs.  The speed is also related to the number of circuits
in the graph to give a relation between speed and complexity.
Extensions to undirected and s-graphs are discussed.
.A
Tiernan, J. C.
.K
algorithm, graph theory, circuit search
algorithm, path search algorithm, searching
.I 1962
.T
GROOVE-A Program to Compose, Store, and Edit Functions of Time
.W
A program which makes possible creating, storing, reproducing,
and editing functions of time is described.  The functions are typical
of those generated by human beings.  Multiple functions (up to 14)
are produced for long periods of time (up to several hours) at
sufficiently high sampling rates to describe fast human reactions
(up to 200 samples per second).  The functions can be used for a
variety of purposes such as the control of machine tools or sound
synthesizers or anything a person normally controls.  The program
operates on a small computer (DDP-224).  Functions are stored on a
disk file.  Functions may be created by real-time human inputs to
the computer which can interact with already stored functions and
computed functions.  Real-time feedback from the process being
controlled is an important link in the system.  The environment for
effective man-machine interaction has been carefully nurtured.
.A
Mathews, M. V.
Moore, F. R.
.K
computer music, music, real-time control, digital control, time
functions, interactive software, hybrid systems, conductor program
.I 1963
.T
Condition Numbers of PEI Matrices
.A
Rokne, J.
.K
matrices, condition numbers, Pei matrices, eigenvectors, eigenvalues
.I 1964
.T
Comment on the Working Set Model for Program Behavior
.A
Bernstein, A.
.K
demand paging, working set, paging rate, multiprogramming
.I 1965
.T
Correction to "Logical" Arithmetic on Computers
with Two's Complement Binary Arithmetic
.A
Ehrman, J. R.
.K
binary arithmetic, unsigned operand arithmetic, maximum
significance arithmetic, full-precision arithmetic
.I 1966
.T
A Generalized Method for Generating Argument/Function Values
.A
Wilson, W. J.
.K
mapping function, decision hierarchy, table look-up
.I 1967
.T
An Improved Algorithm to Produce Complex Primes (Algorithm 401 $A1))
.A
Bratley, P.
.K
number theory, prime numbers, complex numbers
.I 1968
.T
Eigenvalues and Eigenvectors of a Real
General Matrix (Algorithm 343 $F1))
.A
Knight, W.
Mersereau, W.
.K
eigenvalues, eigenvectors, latent roots, Householder's
method, QR algorithm, inverse iteration
.I 1969
.T
Increasing the Efficiency of Quicksort (Algorithm 402 $M1))
.A
Van Emden, M. H.
.K
sorting, quicksort
.I 1970
.T
Unrecorded Magnetic Tape for Information Interchange (9 Track-200 and
800 CPI, NRZI and 1600 CPI, PE)* (Proposed American National Standard)
.K
input-output, magnetic tape, information interchange,
measurement, instrumentation, phase encoded recording
.I 1971
.T
Recorded Magnetic Tape for Information Interchange (1600
CPI, Phase Encoded)* (Proposed American National Standard)
.K
input-output, magnetic tape, information interchange,
measurement, instrumentation, phase encoded recording
.I 1972
.T
A  Nonrecursive List Compacting Algorithm
.W
A simple nonrecursive list structure compacting scheme or garbage
collector suitable for both compact and LISP-like list structures is presented.
The algorithm avoids the need for recursion by using the partial structure as
it is built up to keep track of those lists that have been copied.
.A
Cheney, C. J.
.K
list compacting, garbage collection, compact list, LISP
.I 1973
.T
The Linear Quotient Hash Code
.W
A new method of hash coding is presented and
is shown to possess desirable attributes.  Specifically, the algorithm
is simple, efficient, and exhaustive, while needing little
time per probe and using few probes per lookup.  Performance
data and implementation hints are also given.
.A
Bell, J. R.
Kaman, C. H.
.K
hashing, hash code, scatter storage, calculated
address, search, table, lookup, symbol table, keys
.I 1974
.T
NEATER2: A PL/I Source Statement Reformatter
.W
NEATER2 accepts a PL/I source program and operates on it to produce
a reformatted version.  When in the LOGICAL mode, NEATER2 indicates
the logical structure of the source program in the indentation
pattern of its output.  Logic errors discovered through NEATER2
logical analysis are discovered much more economically than is possible
through compilation and trial runs.  A number of options are
available to give the user full control over the output format and
to maximize the utility of NEATER2 as an aid during the early
stages of development of a PL/I source deck.  One option, USAGE, causes
NEATER2 to insert into each logical unit of coding a statement
which will case the number of times each one is executed to be recorded
during execution.  This feature is expected to provide a
major aid in optimization of PL/I programs.
.A
Conrow, K.
Smith, R. G.
.K
logical analysis of PL/I source, reformatting of PL/I
source, documentation aid, execution time usage data
.I 1975
.T
A Multiple-Precision Division Algorithm
.W
A generalized division algorithm for use with positive integral operands is
presented.  Depending upon the algebraic relationship of the first
two ciphers of the divisor, one or at most two adjustments to the original
divisor and dividend must be performed before the division operation can be
initiated. The uniqueness of this method will cause each trial cipher in the
quotient to be either equal to or one greater than its final replacement.
.A
Mifsud, C. J.
.K
multiple-precision, division, adjustment, generalize
.I 1976
.T
Multi-attribute Retrieval with Combined Indexes
.W
In this paper a file organization scheme designed to
replace the use of the popular secondary index filing scheme
(or inverted files on secondary key fields) is described.
Through the use of redundancy and storing
keys (or access numbers of the records) that satisfy different combinations
of secondary index values in "buckets," it is possible to retrieve
all keys satisfying any input query derived from a subset of
fields by a single access to an index file, although each bucket may
be used for many combinations of values and a combination of
buckets may be required for a given query.  The method which, in its
degenerate case, becomes the conventional secondary index filing
scheme works similarly but has the following advantages: (1) the elimination
of multiple accesses in many cases; (2) the elimination
of false drops; (3) the elimination of computer time to perform intersection
of key sets each qualified for one secondary index field
only; and (4) the avoidance of long strings of keys when an index
field appearing in a query has very few possible values.  Redundancy, in some
cases, is the same as the secondary indexing method. In the general case,
trade-off between the number of accesses for query and redundancy exists.
.A
Lum, V. Y.
.K
file organization, secondary index files, inverted files, information
retrieval, data management, access method, secondary
keys, storage with buckets, rapid retrieval, balanced filing scheme, elimination
of false drops, combining indexes, query, multi-attribute retrieval
.I 1977
.T
An Interactive Display for Approximation by Linear Programming
.W
An interactive program
with a graphical display has been developed for the approximation of
data by means of a linear combination of functions (including
splines) selected by the user.  The coefficients of the approximation
are determined by linear programming so as to minimize the error
in either the L1 or L-infinity norm.  Auxiliary conditions such as
monotonicity or convexity of the approximation can also be imposed. This
interactive system is described and several examples of its use are given.
.A
LaFata, P.
Rosen, J. B.
.K
approximation, data fitting, functional approximation, linear
programming, interactive graphical display, spline functions
.I 1978
.T
The Use of Interactive Graphics To Solve Numerical Problems
.W
With the advent of on-line (time-sharing) computer systems
and graphic terminals, we have available a new dimension
in numerical problem solving capabilities.  Rather than simply use
the new power to achieve fast turnaround, we can develop interactive
routines which are easy to use and also take advantage of the
insight and visual capabilities of the human problem solver.  Several
on-line systems for general purpose mathematical problem solving
have already been implemented as well as some special purpose
systems for solving problems in a particular area such as ordinary
differential equations.  The advantage of restricting the problem
area is that the interface with a user can be greatly simplified.
In this paper we discuss some of the advantages accrued by such
systems and design considerations for interactive routines.  Furthermore,
an implementation of an on-line least squares data-fitting
program, PEG, is presented with results obtained from empirical
data.  In conclusion, area for future work in this field are discussed.
.A
Smith, L. B.
.K
interactive graphics, computer graphics, graphics, least squares,
data-fitting, interactive computing, on-line mathematics
.I 1979
.T
Numerical Inversion of Laplace Transforms (Algorithm 368 $D5))
.A
Stehfest, H.
.K
Laplace transform inversion, integral transformations, integral equations
.I 1980
.T
An Efficient Algorithm for Sorting with
Minimal Storage (Algorithm 347 $M1))
.A
Peto, R.
.K
sorting, ranking, minimal storage sorting, digital computer sorting
.I 1981
.T
Normal Curve Integral (Algorithm 304 $S15))
.A
Holmgren, B.
.K
normal curve integral, probability, special functions
.I 1982
.T
Modified Havie Integration (Algorithm 400 $D1))
.A
Wallick, G. C.
.K
numerical integration, Havie integration, Romberg quadrature,
modified Romberg-quadrature, trapezoid values, rectangle values
.I 1983
.T
Spanning Tree $H) (Algorithm 399)
.A
Seppanen, J. J.
.K
graph, tree, spanning tree
.I 1984
.T
Tableless Date Conversion $Z) (Algorithm 398)
.A
Stone, R. A.
.K
date, calendar
.I 1985
.T
An Integer Programming Problem $H) (Algorithm 397)
.A
Chang, S. K.
Gill, A.
.K
integer programming, change making problem
.I 1986
.T
Student's t-Quantiles $S14) (Algorithm 396)
.A
Hill, G. W.
.K
Student's t-statistic, quantile, asymptotic approximation
.I 1987
.T
Student's t-Distribution $S14) (Algorithm 395)
.A
Hill, G. W.
.K
Student's t-statistic, distribution function,
approximation, asymptotic expansion
.I 1988
.T
A Formalism for Translator Interactions
.W
A formalism is presented for describing the actions
of processors for programming languages-compilers,
interpreters, assemblers-and their interactions in complex systems
such as compiler-compilers or extendible languages.
The formalism here might be used to define and answer such a
question as "Can one do bootstrapping using a meta-compiler
whose metaphase is interpretive?"  In addition an algorithm
is presented for deciding whether or not a given system can
be produced from a given set of component processors.
.A
Earley, J.
.K
translator, compiler, interpreter, bootstrapping,
language processor, compiler-compiler
.I 1989
.T
Transition Network Grammars for Natural Language Analysis
.W
The use of augmented transition network grammars for the analysis
of natural language sentences is described.  Structure-building
actions associated with the arcs of the grammar network allow for the reordering,
restructuring, and copying of constituents necessary to produce
deep-structure representations of the type normally obtained from a
transformational analysis, and conditions on the arcs allow for a
powerful selectivity which can rule out meaningless analyses and take
advantage of semantic information to guide the parsing.  The
advantage of this model for natural language analysis are discussed
in detail and illustrated by examples.  An implementation of an
experimental parsing system for transition network grammars is briefly
described.
.A
Woods, W. A.
.K
computational linguistics, grammars, grammar models, linguistics,
natural language analysis, parsing, semantic interpretation,
transition network grammars, transformational grammars
.I 1990
.T
Numerical Constants (Algorithm)
.A
Dunham, C. B.
.K
numerical algorithm, numerical constants
.I 1991
.T
On the Number of Automorphisms of a Singly Generated Automaton
.A
Bavel, Z.
.K
automata, finite automata, singly generated automata, automorphisms,
generators, length of state, minimal-length generators, orbit
.I 1992
.T
Comment on Bell's Quadratic Quotient Method for Hash Code Searching
.A
Lamport, L.
.K
hashing, hash code, scatter storage, calculated address,
clustering, search, symbol table, keys, table look-up
.I 1993
.T
Regular Coulomb Wave Functions (Algorithm 292 $S22))
.A
 Cody, W. J.
Paciorek, K. A.
.K
Coulomb wave functions, wave functions, regular Coulomb wave functions
.I 1994
.T
Decision Table Translation $H) (Algorithm 394)
.A
Dial, R. B.
.K
Decision table, decision table translation
.I 1995
.T
Special Series Summation with Arbitrary Precision $C6) (Algorithm 393)
.A
Abdali, S. K.
.K
function evaluation, series summation, approximation
.I 1996
.T
Systems of Hyperbolic PDE $D3) (Algorithm 392)
.A
Smith, R. R.
McCall, D.
.K
hyperbolic p.d.e., characteristic, extrapolation,
second order p.d.e., quasilinear p. d. e.
.I 1997
.T
Increasing the Efficiency of Quicksort
.W
A method is presented for the analysis of various generalizations of
quicksort.  The average asymptotic number of comparisons needed is shown
 to be an log^2(n).  A formula is derived expressing a in terms of
the probability distribution of the "bound" of a partition.  This
 formula assumes a particularly simple form for a generalization already
considered by Hoare, namely, choice of the bound as median
of a random sample. The main contribution of this paper is another
generalization of quicksort, which uses a bounding interval instead
of a single element as bound.  This generalization turns out to
be easy to implement in a computer program.  A numerical approximation
shows that a = 1.140 for this version of quicksort compared with
1.386 for the original.  This implies a decrease in number of comparisons of
18 percent; actual tests showed about 15 percent saving in computing time.
.A
van Emden, M. H.
.K
sorting, quicksort, information content, entropy, distribution of median
.I 1998
.T
Complex Matrix Inversion Versus Real
.W
A comparison of complex matrix with real matrix inversion
is made.  It is shown that the complex inversion can be up to
twice as fast as the real inversion.  Further, the rounding error
bound for complex inversion is about one-eighth that of real,
for Gaussian elimination.  Using extended inner product
accumulation the bound is half of the real system.
.A
Ehrlich, L. W.
.K
complex matrix inversion, matrix inversion, inversion, rounding errors,
rounding error bound, error bounds, complex rounding error bounds
.I 1999
.T
Optimal Starting Approximations for Generating
Square Root for Slow or No Divide
.W
On machine with slow or no division, it is preferable to
use an iterative scheme for the square root different from
the classical Heron scheme.  The problem of optimal initial
approximants is considered, and some optimal polynomial initial
approximations are tabulated.
.A
Wilson, M. W.
.K
square root, Newton-Raphson iteration, optimal approximants
.I 2000
.T
A Variation of the Goodman-Lance Method for
the Solution of Two-Point Boundary Value Problems
.W
A recently published method for the interpolative
solution of nonlinear equations is improved,
and applied to give a significant variation of the Goodman-Lance
method for the solution of two-point boundary value problems.
The resulting method applies in particular to the numerical solution
of optimal control problems in the Euler-Lagrange formulation.
Quantitative estimates are presented which indicate that the variation
is nearly twice as fast on some problems in the latter context.
.A
Kimble, G. W.
.K
Goodman-Lance, boundary-value problems,
Newton's method, nonlinear equations,
optimal control, optimization, ordinary differential equations,
secant method, interpolative solution, orthogonal matrices
.I 2001
.T
Integrating Square Roots
.W
Differential equation of the (y')^2 = f(y) are difficult to integrate
numerically because of the singularity at points where f(y) vanishes.  A
simple trick removes the singularity.
.A
Moler, C. B.
Solomon, L. P.
.K
quadrature, differential equations
.I 2002
.T
AMESPLOT-A Higher Level Data Plotting Software System
.W
AMESPLOT is an extensible software system designed to make the display of
data as simple, painless, and neat as possible.  The system described is
hardware-independent and has been implemented on a variety of installations,
of different manufacturers, having diverse configurations.  The elements
common to all types of data plots are outlined and the way in which these
elements may be combined into a system based on simple modules is demonstrated.
These modules are specified independently and are independent of the axis
systems or other attributes of the plot.  This enables plots of any
complexity to be constructed by adding or replacing modules.  The
basic syntax of AMESPLOT is outlined, and a brief description is given
of its current utility software, consisting of "macros" to produce
self-scaled plots, formal tablets of text-interspersed with subplots,
map coastlines, and 3-D plots.  The system was formulate
d in a way such that the user could supply the minimum of information,
and it should be fully integrable with user's program written
in most conventional higher languages.  The functions of positioning,
locating, and scaling (in the layout of multiple subplots) of
axes, labels, and all other elements of the plot are handled automatically
by the software system unless the user specifies otherwise.  The structuring
of plots from multiple, independent, self-contained subplots is described.
Transformation, projection, scaling, rotation, or shifting of entire plots or
subplots by the action of one or more simple modules is possible.  The user
may interact freely with AMESPLOT at three levels, enabling him to construct
his own data markers, alphabetic characters, and transformations, and
to produce a variety of artistic and other effects.
.A
Hirschsoln, I.
.K
computer graphics, data potting, data display
syntax, hardware independent software,
display device independent software, plot elements, self-scaled plots,
user interaction, tablet organization, map display, projection
.I 2003
.T
An Interactive Software System for Computers-Aided
Design:  An Application to Circuit Project
.W
The characteristics of an interactive software system, intended to constitute
an interface between designer and computer during various steps of
the design process, are presented.  The main emphasis is given to the
description of the features of the two high level user oriented
languages, operating at different levels, on which the interaction
is based.  The first one is IMOL, an interactive monitor language,
which is designed to perform the overall and control functions
of the software system; its design criteria provide the user with
commands which are both simple and efficient in order to perform all
the functions needed in computer-aided circuit design.  The second one is
COIF, a circuit oriented graphic language, which is designed
to describe, generate, and manipulate graphic problem specifications;
it is an  extension of Fortran with graphic-type variables,
so that the designer who is familiar with Fortran need not learn a new
language.  The application to computer-aided circuit design
is in particular examined; on the other hand, the adopted design
criteria provide sufficient generality to extend the use of the two languages
to different computer-assisted applications.
.A
Bracchi, G.
Somalvico, M.
.K
interaction, graphics, computer graphics, computer-aided design, circuit
design, software system, software organization, language,
monitor language, graphic language, extended Fortran
.I 2004
.T
A Procedure for Generation of Three-dimensional
Half-toned Computer Graphics Presentations
.W
A description is given of an algorithm for producing computer generated
half-tone presentations of three-dimensional polygonal surface structures.
This algorithm achieves a significant increase in speed of computation over
the Warnock algorithm developed at the University of Utah and implemented
also on the Coordinated Science Laboratory CDC 1604 computer
system at the University of Illinois.  The history leading to the algorithm
development and then the algorithm itself are described.
Results are presented and are compared with computer runs achieved
by the Warnock approach.  An extension of the procedure to variable position
illumination sources is also given.
.A
Bouknight, W. J.
.K
half-tone computer graphics, line-scan image processing,
hidden surface, polygonal surface structure presentations
.I 2005
.T
Proposed Revision of American National Standard X3.21-1967,
"Rectangular Holes in Twelve-Row Punched Cards"*
.K
tabulating-card, Hollerith card, keypunch, information processing
.I 2006
.T
Proposed American National Standard
.A
Kerpelman, C.
.K
State identifiers, State abbreviation, States of the United States, data
elements, data codes, numeric codes, geopolitical subdivisions, geographic codes
.I 2007
.T
Algorithms Policy/Revised August 1970
.I 2008
.T
Gaussian Quadrature Formulas (Algorithm 331 $D1))
.A
Wise Jr., W. R.
.K
quadrature, Gaussian quadrature, numerical integration, weight function,
orthogonal polynomials, Newton's method, successive deflation
.I 2009
.T
Simpson's Rule for Multiple Integration (Algorithm 233 $D1))
.A
Proll, L. G.
.K
numerical integration, multiple integration, Simpson's rule
.I 2010
.T
Unitary Symmetric Polynomials $Z) (Algorithm 391)
.A
McKay, J.
.K
symmetric polynomials, unitary symmetric polynomials
.I 2011
.T
Sequency Ordered Walsh Functions $S22) (Algorithm 390)
.A
Hubner, H.
.K
Walsh functions, sequency ordered Walsh functions
.I 2012
.T
Binary Ordered Walsh Functions $S22) (Algorithm 389)
.A
Hubner, H.
.K
Walsh functions, binary ordered Walsh functions
.I 2013
.T
Rademacher Function $S22) (Algorithm 388)
.A
Hubner, H.
.K
Rademacher function
.I 2014
.T
Function Minimization and Linear Search $E4) (Algorithm 387)
.A
Fielding, K.
.K
function minimization, relative minimum, quasi-Newton method
.I 2015
.T
A Technique for Generating Almost Optimal
Floyd-Evans Productions for Precedence Grammars
.W
A technique is developed for generating almost optimal Floyd-Evans productions
given a precedence grammar. A graph formulation is used for the problem of
merging productions.  The productions generated correspond to the minimum cost
inverse-arborescence of that graph.  The validity of the technique is
demonstrated for weak precedence grammars defined here, but the productions
mechanically generated for any precedence grammar can often be modified in
such a way that correct, almost optimal parsers are obtained.
.A
Ichbiah, J. D.
Morse, S. P.
.K
translator writing systems, syntactic analysis, Floyd-Evans
productions, precedence grammars, translator optimization,
merger algorithm, minimum cost inverse-arborescence, graph theory
.I 2016
.T
The Instrumentation of Multics
.W
An array of measuring tools devised to aid in the implementation of a prototype
computer utility is discussed.  These tools include special hardware
clocks and data channels, general purpose programmed probing
and recording tools, and specialized measurement facilities.  Some
particular measurements of interest in a system which combines demand
paging with multiprogramming are described in detail.  Where appropriate,
insight into effectiveness (or lack there of) of individual tools is provided.
.A
Gintell, J. W.
Saltzer, J. H.
.K
instrumentation, performance measurement,
multiprogramming systems, measuring tools, system analysis, Multics,
metering, event tracing, demand paging, script driven
measurement
.I 2017
.T
Sorting in a Paging Environment
.W
This sorting study was part of an extensive measurement project
undertaken on the M44/44X, an experimental paging system which was
conceived and implemented at IBM Research in order to explore the
virtual machine concept.  The study was concerned with the implementation
of sorting procedures in the context of the dynamic paging
environment characteristic of virtual memory machines.  Descriptions of
the experimental sort programs and analysis of the performance
measurement results obtained for them are presented. The insight gained
from the experimental effort is used to arrive at a set of
broad guidelines for writing sort programs for a paging environment.
.A
Brawn, B. S.
Gustavson, G.
Mankin, E. S.
.K
sorting, merging, virtual machines, paging systems, dynamic
storage allocation, measurement of systems program behavior,
performance evaluation, memory management
.I 2018
.T
Full Table Quadratic Searching for Scatter Storage
.W
The quadratic residue search method for hash tables avoids much
of the clustering experienced with a linear search method.  The simple
quadratic search only accesses half the table.  It has been shown
that when the length of the table is a prime of the form 4n+3, where n
is an integer, the whole table may be accessed by two quadratic
searches plus a separate access for the original entry point. A search
method is presented which is computationally simple, has all the advantages
of the quadratic search, and yet accesses all the table in one sweep.
.A
Day, A. C.
.K
quadratic residue, search method, hash tables, scatter storage,
dictionary look-up, quadratic search, searching, hashing,
hash code, clustering, collisions
.I 2019
.T
Normalization Techniques for Hand printed Numerals
.W
Family of pattern standardization
techniques based on geometrical projection is applied to a file of
digitized hand printed numerals obtained from sales clerks. The
principle involves transforming a quadrilateral specified in terms
of the convex hull of each pattern into a square. The amount of
overlap within each class of characters versus the amount between classes
is used to evaluate the degree of normalization achieved with respect to other
published methods including size and shear normalization through moments.
.A
Nagy, G.
Tuong, N.
.K
pattern recognition, character recognition, normalization,
projective transformation, central projection, hand
printed characters, handwriting, linear transformation,
size normalization, mapping, pattern preprocessor
.I 2020
.T
The Allocation of Computer Resources-Is Pricing the Answer?
.W
The widespread use of complex third generation computing systems has led to a
much broader concern about the means by which the resources of these systems
are allocated among the user community.  One means that is suggested
more and more frequently is a pricing procedure.  In this
paper the manner in which one would like to allocate computing resources
is considered, and then the extent to which a pricing mechanism fits this mold
is discussed.  Inasmuch as pricing must serve as a rationing mechanism at
times, consideration is given to the means by which prices can be adjusted
flexibly in order to make a dynamic allocation of resources.  Consideration is
also given to the means by which users can be insulated from the harmful
effects of frequent price fluctuations.  Although the subject of pricing has
been given a lot of attention recently, a number of misconceptions
persist about its purpose and its operation.  An attempt is made to clarify
some of these misunderstandings and to highlight the advantages and
disadvantages and to highlight the advantages and disadvantages of pricing. Two
illustrative pricing systems are also discussed in order to demonstrate the
applicability of pricing in quite different environments.
.A
Nielsen, N. R.
.K
allocation mechanisms, charging, computer pricing,
costing, flexible pricing, pricing, priority charges,
resource allocation, user motivation
.I 2021
.T
A Comment on Axiomatic Approaches to Programming
.A
Hunt, B.R.
.K
axiomatic method, proofs of programs,
homomorphic structure in programming
.I 2022
.T
Note on an Anomaly in Paging
.A
Pomeranz,J. E.
.K
paging machines, demand paging, replacement algorithm
.I 2023
.T
A Note on Data Base Deadlocks
.A
Baecker, H. D.
.K
data base, synchronization, locking, deadlock, reference count
.I 2024
.T
Comments on a Paper by Lowe
.A
Sattley, K.
Millstein, R.
.K
automatic segmentation, program connectivity
.I 2025
.T
Student's t-Distribution; Jacobi Polynomials;
Modified Romberg Quadrature;
Factorial Analysis of Variance; (Algorithms 332,344,351,359)
.A
Sale, A. H. J.
.K
Fortran standards
.I 2026
.T
Exponential Integral (Algorithm 385 $S13))
.A
Ng, E. W.
.I 2027
.T
Ricatti-Bessel Functions of First and Second Kind (Algorithm 22 $S17))
.A
Bray, T.
.K
Ricatti-Bessel functions, Bessel functions
of fractional order, spherical Bessel functions
.I 2028
.T
Greatest Common Divisor of n Integers
and Multipliers $A1) (Algorithm 386)
.A
Bradley, G. H.
.K
greatest common divisor, Euclidean algorithm,
number theory, diophantine equations
.I 2029
.T
Exponential Integral $S13) (Algorithm 385)
.A
Paciorek, K. A.
.K
exponential integral, special functions, rational Chebyshev approximation
.I 2030
.T
Context-Sensitive Parsing
.W
This paper presents a canonical form for context-sensitive
derivations and a parsing algorithm which finds
each context-sensitive analysis once and only once.  The amount of memory
required by the algorithm is essentially no more than the required to
store a single complete derivation.  In addition, a modified
version of the basic algorithm is presented which blocks infinite analyses
for grammars which contain loops.  The algorithm is
also compared with several previous parsers for context-sensitive
grammars and general rewriting systems, and the difference between
the two types of analyses is discussed.  The algorithm appears to
be complementary to an algorithm by S. Kuno in several respects, including
the space-time trade-off and the degree of context dependence involved.
.A
Woods, W. A.
.K
context-sensitive grammars, context-sensitive parsing, formal grammars,
formal language theory, parsing, parsing algorithms, recognition algorithms
.I 2031
.T
Algorithm and Bound for the Greatest Common Divisor of n Integers
.W
A new version of the Euclidean
algorithm for finding the greatest common divisor of n integers a(i)
and multipliers x(i) such that gcd = x(1)a(1) + ... + x(n)a(n)
is presented.  The number of arithmetic operations and the number
of storage locations are linear in n.  A theorem of Lame that gives a bound
for the number of iterations of the Euclidean algorithm for two integers
is extended to the case of n integers.  An algorithm to construct a minimal
set of multipliers is presented.  A Fortran program for the algorithm appears
as Comm. ACM Algorithm 386.
.A
Bradley, G. H.
.K
greatest common divisor, Euclidean algorithm,
number theory, diophantine equations
.I 2032
.T
File Structures Using Hashing Functions
.W
A general method of file structuring is proposed which uses a hashing
function to define tree structure.  Two types of such trees are examined,
and their relation to trees studied in the past is explained.Results for the
probability distributions of path lengths are derived and illustrated.
.A
Coffman Jr., E. G.
Eve, J.
.K
Data structures, tree structures, file structures, scatter
tables, hashing functions, information retrieval
.I 2033
.T
Space/Time Trade-offs in Hash Coding with Allowable Errors
.W
In this paper trade-offs among certain computational factors
a given set of messages.  Two new hash-coding methods are examined
and compared with a particular conventional hash-coding method.
The computational factors considered are the size of the hash area
(space), the time required to identify a message as a nonmember of the
given set (reject time), and an allowable error frequency.  The new methods
are intended to reduce the amount of space required to contain the hash-coded
information from that associated with conventional methods.  The reduction in
space is accomplished by exploiting the possibility that a small fraction of
errors of commission may be tolerable in some applications, in particular,
applications in which a large amount of data is involved and a core resident
hash area is consequently not feasible using conventional methods.  In such
applications, it is envisaged that overall performance
could be improved by using a smaller core resident hash area in
conjunction with the new methods and, when necessary, by using some
secondary and perhaps time-consuming test to "catch" the small
fraction of errors associated with new methods.  An example is discussed
which illustrates possible areas of application for the new
methods.  Analysis of the paradigm problem demonstrates that allowing
a small number of test messages to be falsely identified as
members of the given set will permit a much smaller hash
area to be used without increasing reject time.
.A
Bloom, B. H.
.K
hash coding, hash addressing, scatter storage, searching, storage
layout, retrieval trade-offs, retrieval efficiency, storage efficiency
.I 2034
.T
The Mobile Programming System: STAGE2
.W
STAGE2 is the second level of a bootstrap sequence which
is easily implemented on any computer.  It is a flexible,
provided by STAGE2 are summarized, and the implementation techniques
which have made it possible to have STAGE2 running on a new
machine with less than one man-week of effort are discussed.  The approach
has been successful on over 15 machines of widely varying
characteristics.
.A
Waite, W. M.
.K
bootstrapping, macro processing, machine independence,
programming languages, implementation techniques
.I 2035
.T
Conversational Access to a 2048-Word Machine
.W
LAP6 is an on-line system running on a 2048-word LINC which provides full
facilities for text editing, automatic filing and file maintenance, and
program preparation and assembly.  It focuses on the preparation and editing
of continuously displayed 23,040-character text strings (manuscripts) which
can be positioned anywhere by the user and edited by simply adding
and deleting lines as though working directly on an elastic scroll.
Other features are available through a uniform command set which itself can
be augmented by the user.  The machine, although small,
aids program design by providing display scope and premarked
randomly addressable LINC tapes as standard items, in an environment
similar to that of a sophisticated terminal.  The tapes are logically
similar to a disk.  Priority was given to the design of efficient
tape algorithms to minimize the limitations of the small memory.  Techniques
developed for handling scroll editing, filing, and the layered system
structure are outlined.  LAP6 is used by about 2000 people in 11 countries.
Its design was strongly influenced by performance criteria established in
interviews held with LINC users themselves during the specification period.
.A
Wilkes, M. A.
.K
conversational computer access,
display editing, display oriented system, filing algorithms, LAP6,
layering, LINC, man-machine communication, on-line editing, on-line efficiency,
on-line environment, scroll editing, small machine system, tape filing, tape
oriented system, text editing
.I 2036
.T
An Interactive Command Generating Facility
.W
A facility to permit conversationally controlled tasks
to be executed in a noninteractive environment is proposed.
A means by which programs can generate interactive time-sharing commands
and receive the corresponding output response is presented.  The commands
will be invoked as if they had been typed at a console keyboard.  It is
argued that this facility will help overcome some of the current limitations
in man-computer communication. A set of functions to accomplish the above
which could be embedded into any string processing language is suggested,
and necessary information pertinent to implementation of the facility on
existing time-sharing systems is given.
.A
Grant, C. A.
.K
time-sharing, command languages, pseudo-teletype, interaction,
conditional job control, operating systems
.I 2037
.T
Permutations of a Set with Repetitions (Algorithm 383 $G6))
.A
Chase, P. J.
.K
permutations and combinations, permutations
.I 2038
.T
Combinations of M Out of N Objects (Algorithm 382 $G6))
.A
Chase, P. J.
.K
permutations and combinations, permutations
.I 2039
.T
Permanent Function of a Square Matrix I and II (Algorithm 361 $G6))
.A
Shriver, B.
Eberlein, P. J.
Dixon, R. D.
.K
matrix, permanent, determinant
.I 2040
.T
Modified Romberg Quadrature (Algorithm 351 $D1))
.A
Wallick, G. C.
.K
numerical integration, Romberg quadrature, modified Romberg quadrature,
trapezoid values, rectangle values
.I 2041
.T
Shellsort (Algorithm 201 $M1))
.A
Chandler, J. P.
Harrison, W. C.
.K
sorting, minimal storage sorting, digital computer sorting
.I 2042
.T
Treesort 3 (Algorithm 245 $M1))
.W
The certification of an algorithm can take
the form of a proof that the algorithm is correct.  As an illustrative
but practical example, Algorithm 245, TREESORT 3 for sorting
an array, is proved correct.
.A
London, R. L.
.K
proof of algorithms, debugging, certification,
metatheory, sorting, in-place sorting
.I 2043
.T
Eigenvalues and Eigenvectors of a Real
Symmetric Matrix $F2) (Algorithm 384)
.A
Stewart, G. W.
.K
real symmetric matrix, eigenvalues, eigenvectors, QR algorithm
.I 2044
.T
Permutations of a Set with Repetitions (Algorithm 383 $G6))
.A
Chase, P. J.
.K
permutations and combinations, permutations
.I 2045
.T
Combinations of M Out of N Objects (Algorithm 382 $G6))
.A
Chase, P. J.
.K
permutations and combinations, permutations
.I 2046
.T
A Relational Model of Data for Large Shared Data Banks
.W
Future users of large data banks must be protected from having to know how the
data is organized in the machine (the internal representation).  A prompting
service which supplies such information is not a satisfactory
solution.  Activities of users at terminals and most application
programs should remain unaffected when the internal representation
of data is changed and even when some aspects of the external representation
are changed.  Change in data representation will often be needed as a result
of changes in query, update, and report traffic and natural growth in the
types of stored information.  Existing noninferential, formatted data systems
provide users with tree-structured files or slightly more general network
models of the data.  In Section 1, inadequacies of these models are discussed.
A model based on n-ary relations, a normal form for data base relations,
and the concept of a universal form for data base relations,
and the concept of a universal data sublanguage are introduced.  In
Section 2, certain operations on relations (other than logical
inference) are discussed and applied to the problems
of redundancy and consistency in the user's model.
.A
Codd, E. F.
.K
data bank, data base, data structure, data organization,
hierarchies of data, networks of data, relations, derivability,
redundancy, consistency, composition, join, retrieval
language, predicate calculus, security, data integrity
.I 2047
.T
Incorporating Origin Shifts into the QR
Algorithm for Symmetric Tridiagonal Matrices
.W
The QR iteration for the eigenvalues of a symmetric tridiagonal matrix can
be accelerated by incorporating a sequence of origin shifts.  The origin shift
may be either subtracted directly from the diagonal elements of
the matrix or incorporated by means of an implicit algorithm.  Both
methods have drawbacks: the direct method can unnecessarily degrade small
eigenvalues, while the implicit method can effectively loose the shift and
thereby retard the convergence.  This paper presents a new method which has
neither drawback.
.A
Stewart, G. W.
.K
eigenvalues, eigenvectors, QR method, origin
shifts, symmetric tridiagonal matrix
.I 2048
.T
Comparison of Several Adaptive Newton-Cotes Quadrature Routines
in Evaluating Definite Integrals with Peaked Integrands
.W
This report compares the performance of five different adaptive quadrature
schemes, based on Newton-Cotes (2N + 1) point rules (N = 1, 2, 3, 4, 5), in
approximating the set of definite integrals INTEGRAL$1/(x^2 + p^2)) dx with
relative accuracy e.
.A
Hillstrom, K. E.
.K
adaptive Newton-Cotes quadrature, quadrature scheme comparison,
definite integral evaluation, adaptive numerical in tegration, Newton-Cotes
integration, peaked integrand integration, quadrature efficiently
plot, New-Cotes rules applications, Newton-Cotes rules modifications
.I 2049
.T
Accurate Floating-Point Summation
.W
This paper describes an alternate method for summing a set
of floating-point numbers.  Comparison of the error bound for
this method with that of the standard summation method shows that it
is considerably less sensitive to propagation of round-off error.
.A
Linz, P.
.K
summation, floating-point addition,
round-off error, round-off propagation
.I 2050
.T
Automatic Parsing for Content Analysis
.W
Although automatic syntactic and semantic analysis is not yet possible for
all of an unrestricted natural language text, some applications, of which
content analysis is one, do not have such a stringent coverage requirement.
Preliminary studies show that the Harvard Syntactic Analyzer can
produce correct and unambiguous identification of the subject and
object of certain verbs for approximately half of the relevant occurrences.
This provides a degree of coverage for content analysis variables which
compares favorably to manual methods, in variables which compares favorably
to manual methods, in which only a sample of the total available text is
normally processed.
.A
Damerau, F. J.
.K
Content analysis, parsing, syntactic analysis, natural language processing,
information retrieval, language analysis, text processing
.I 2051
.T
A PL/I Program to Assist the Comparative Linguist
.W
A practical PL/I program is described which
can assist comparative linguists to determine
the regular sound correspondences between genetically related languages.
The investigator must arrange data for input by aligning pairs
of suspected cognates.  The program tabulates the correspondences,
and uses list processing techniques to sort and count them.
Each pair of words is then assigned a relative value that is a function
of the total frequency in the data of each correspondence found
in that pair of words.  The output is a list of all correspondence
types with their frequency of occurrence in the data, and a
separate listing of each correspondence with all word-pairs showing
that correspondence (unless their relative value is below an arbitrarily
chosen cutoff point).  The article explains the usefulness,
as well as the limitations, of the programs, and illustrates its
use with a small portion of hypothetical data.
.A
Frantz, D. G.
.K
comparative linguistics, natural
language processing, comparative method, historical linguistics, diachronic
linguistics, genetic relationship, sound change, sound
correspondence, regular correspondence, list processing
.I 2052
.T
Scheduling to Reduce Conflict in Meetings
.W
Conflicts in scheduling can be treated as defining an undirected linear graph
independently of the relation of the activities in conflict to additional
constraints of time and space.  Each connected component of such a graph,
which can be found by an algorithm described by Gotlieb and Corneil,
corresponds to a set of events that must be scheduled at different times.
.A
Grimes, J. E.
.K
allocation, conflict matrix, connected component, scheduling, spanning
tree, undirected linear graph
.I 2053
.T
On the Conversion of Decision Tables to Computer Programs
.W
The use of execution time diagnostics in pinpointing ambiguities in decision
tables is discussed.  It is pointed out that any attempt at resolving
ambiguities at compile time will, in general, be impossible.  It
is shown that, as a consequence, tree methods of converting decision
tables to programs are inadequate in regard to ambiguity detection.
Two algorithms for programming decision tables whose merits
are simplicity of implementation and detection of ambiguities at
execution time are presented. The first algorithm is for limited entry
decision tables and clarifies the importance of proper coding
of the information in the decision table.  The second algorithm programs
a mixed entry decision table directly without going through
the intermediate step of conversion to a limited entry form, thereby
resulting in storage economy.  A comparison of the algorithms and others
proposed in the literature is made.  Some features of a decision table
to Fortran IV translator for the IBM 7044 developed by the authors are given.
.A
Muthukrishnan, C. R.
Rajaraman, V.
.K
decision tables, diagnostic aids, system analysis, business applications
.I 2054
.T
On the Feasibility of Voice Input to
an On-line Computer Processing System
.W
An on-line digital computer processing system is considered in which an
ordinary telephone is the complete terminal device, input to the computer
being provided as a sequence of spoken words, and output to the user being
audio responses from the machine.  The feasibility of implementing such a
system with a FORTRAN-like algebraic compiler as the object processor is
considered.  Details of a specific word recognition program are given.  This
technique depends on three simplifying restrictions, namely, a "small"
vocabulary set, "known" speakers, and a "moment of silence"
between each input word.  Experimental results are presented giving
error rates for different experimental conditions as well as the machine
resources required to accommodate several users at a time. The results show
that at this time it is both economically and logically feasible to handle at
least 40 users at a time with an IBM 360/65 computer.
.A
Elder, H. A.
.K
speech recognition, word recognition, pattern-matching, pattern
recognition, time-sharing, remote access, voice input, speech input,
telephone input/output, acoustic signal, spoken-word input, talking to
computers, man-machine interaction
.I 2055
.T
Subroutine to Perform In-Situ Transposition
of a Rectangular Matrix (Algorithm 380)
.A
Lachenmaier, R.
.K
rectangular matrix, transpose
.I 2056
.T
Gomory (Algorithm 263A $H))
.A
Proll, L. G.
.K
linear programming, integer variables, dual method
.I 2057
.T
Random Vectors Uniform in Solid Angle (Algorithm 381 $G5))
.A
Knop, R. E.
.K
random number, random vector, random number generator, probability
distribution, frequency distribution, simulation, Monte Carlo
.I 2058
.T
In-Situ Transposition of a Rectangular Matrix (Algorithm 380 $F1))
.A
Laflin, S.
Brebner, M. A.
.K
rectangular matrix, transpose
.I 2059
.T
A Language for Treating Graphs
.W
A language for the representation of graph is described, and the formulation of
graph operations such as node and/or link deletion or insertion, union,
intersection, comparison, and traversal of graphs is given.  Graphs
are represented by linked lists.  The language is syntactically defined
as an extension to ALGOL 60, and it is translated into ALGOL
by means of a syntax-driven compiler.  Application areas for this language are
operation research, network problems, control theory, traffic problems, etc.
.A
Crespi-Reghizzi, S.
Morpurgo, R.
.K
graphs, oriented, nonoriented, multiple,
colored graph, language extended ALGOL,
operator-precedence, syntax-driven compiler,
operation research, network, traffic
.I 2060
.T
GEDANKEN-A Simple Typeless Language Based on the
Principle of Completeness and the Reference Concept
.W
GEDANKEN is an experimental programming language with the following
characteristics.  (1) Any value which is permitted in some context of the
language is permissible in any other meaningful context.  In particular,
functions and labels are permissible  results of functions and values
of variables.  (2) Assignment and indirect addressing are formalized
by introducing values, called reference, which in turn possess
other values.  The assignment operation always affects the relation
between some reference and its value,  (3) All compound data
structures are treated as functions.  (4) Type declarations are
not permitted.  The functional approach to data structures and the
use of references insure that any process which accepts some data
structure will accept any logically equivalent structure, regardless
of its internal representation.  More generally, any data structure
may be implicit; i.e. it may be specified by giving an arbitrary
algorithm for computing or accessing its components.  The existence of
label variables permits the construction of coroutines,
quasi-parallel processes, and other unorthodox control mechanisms.
A variety of programming examples illustrates the generality of the language.
Limitations and possible extensions are discussed briefly.
.A
Reynolds, J. C.
.K
programming language, data structure, reference, assignment, coroutine,
quasi-parallel process, typeless language, applicative language,
lambda calculus, list processing, nondeterministic algorithm
.I 2061
.T
An Algorithm for the Construction Of Bounded-Context Parsers
.W
An algorithm is described which accepts an arbitrary context-free
grammar and constructs a bounded-context parser for
it whenever such a parser exists.  In the first part of the paper
the definition of a context-free grammar and the working of a
bounded-context parser are recalled.  The notion of reduction class for
a context-free grammar is then introduced and its connection with
the structure of a bounded-context parser is indicated.  Next,
pushdown automata which generate the different reduction classes
of a context-free grammar are defined.  Finally, the algorithm is described;
it essentially carries out an exhaustive study of all possible
runs of the pushdown automata generating the reduction classes.
In the second part, the utility of the algorithm is discuss
ed in the light of the experience gained from its use in compiler design.
The algorithm is claimed to be particularly useful in the
simultaneous design of a language and a compiler for it.
.A
Loeckx, J.
.K
bounded-context parsing, bounded-context syntactic analysis, parser
construction, syntactical analyzer construction, generators, compiler
compilers, compiler writing systems, translator writing systems metacompilers,
context-free grammars, formal languages, pushdown automata
.I 2062
.T
The Application of Sequential Sampling
to Simulation: An Example Inventory Model
.W
Four different sequential sampling procedures are applied
to the analysis of data generated by a computer simulation
experiment with a multi-item inventory model.  For each procedure
the cost of computer time required to achieve given levels of
statistical precision is calculated.  Also the cost of computer time
using comparable fixed sample size methods is calculated.  The
computer costs of fixed sample size procedures versus
sequential sampling procedures are compared.
.A
Sasser, W. E.
Burdick, D. S.
Graham, D. A.
Naylor, T. H.
.K
simulation, inventory models, sequential
sampling, models, experimental design
.I 2063
.T
Translation Equations (Errata)
.A
Vere, S.
.I 2064
.T
Operations on Generalized Arrays with the Genie Compiler
.W
Operations on vectors, matrices, and higher dimensional storage arrays are
standard features of most compilers today.  The elements of such structures are
usually restricted to be scalars.  For many sophisticated applications
this restriction can impose cumbersome data representations.
An efficient system has been devised and implemented which allows
the elements of multidimensional arrays to themselves be multidimensional
arrays.  This system was developed from a storage structure
in which the location, length, and content of each array is described
by a codeword which can be interpreted by the system.  Code words may describe
arrays containing more codewords, thus providing
all needed descriptive information for hyperstructures of any form.
.A
Sitton, G. A.
.K
multidimensional arrays, matrix operations,
storage control, subscripting, compilers
.I 2065
.T
A Programming System for the On-line Analysis of Biomedical Images
.W
A preliminary description of the software for a computer-display
system is given with special emphasis on the  man-machine interaction. This
system is intended for a wide variety of biomedical applications.
As an example, the methods are applied to the karyotyping of chromosomes.  The
system is separated into four programming tasks: picture transformations, file
maintenance, picture structuring, and display management.  Picture structuring
is considered as the vehicle for man-machine communication.
A prototype data format for pictures, called a picture-form, is developed.
Structure operators are defined which manipulate picture-forms to produce
new pictures-forms.  Many of the ideas are taken from the symbolic mathematical
laboratory at MIT conceived by Marvin Minsky.
.A
Hodes, L.
.K
image processing, biomedical image processing, on-line image processing,
semiautomatic image processing, data structure, structure operators,
picture processing, biomedical picture processing, on-line picture
processing, semiautomatic picture processing, semiautomatic
karyotyping, karyotyping, list processing picture processing
.I 2066
.T
An Algol Construction for Procedures as Parameters of Procedures
.A
Knight, K. R.
.K
Algol, procedures, parameters, side effects
.I 2067
.T
Comment on Lawler's Multilevel Boolean Minimization
.A
DeVries, R. C.
.K
multilevel logic design, generalized prime implicants,
minimal forms, minimization, incompletely
specified functions
.I 2068
.T
Comment on Multiprogramming Under a Page on Demand Strategy
.A
Smith, J. L.
.K
multiprogramming, paging, modeling
.I 2069
.T
Comments on a Paper by Wallace and Mason
.A
Heess Jr., W. F.
.K
page-on-demand, demand paging, time-sharing multiprogramming,
Markovian computer models, scheduling strategies,
operating systems, memory management
.I 2070
.T
A Formal System for Information Retrieval from Files
.A
Hsiao, D.
Harary, F.
.I 2071
.T
Filon Quadrature (Algorithm 353 $D1))
.A
Fosdick, L. D.
Einarsson, Bo
.K
quadrature, Filon quadrature, integration, Filon
integration, Fourier coefficients, Fourier series
.I 2072
.T
Modified Romberg Quadrature (Algorithm 351 $D1))
.A
Cook, N. D.
.K
numerical integration, Romberg quadrature,
trapezoid values, rectangle values, error bound
.I 2073
.T
Solution of Linear Programs in 0-1 Variables
by Implicit Enumeration (Algorithm 341 $H))
.A
Guignard, M. M.
.K
linear programming, zero-one variables, partial enumeration
.I 2074
.T
Sqank (Algorithm 379 $D1))
.A
Lyness, J. N.
.K
numerical integration, integration rule, adaptive integration,
automatic integration, Simpson's rule, numerical quadrature, quadrature,
quadrature rule, adaptive quadrature,
automatic quadrature, round-off error control
.I 2075
.T
Discretized Newton-Like Method for Solving a System
of Simultaneous Nonlinear Equations (Algorithm 378 $C5))
.A
Pankiewicz, W.
.K
Newton's method, nonlinear equations, interpolating polynomials
.I 2076
.T
Cubic Splines on Uniform Meshes
.W
A very simple procedure is presented for constructing cubic splines,
periodic or nonperiodic, on uniform meshes.  Arcs of two cubics suffice
to construct a basis of cardinal splines.  An algorithm is given which
requires only minimal storage and computation and permits easy trade-off
of one against the other.
.A
Nilson, E. N.
.K
simple spline representation, cardinal splines, uniform mesh splines
.I 2077
.T
The Cyclical Majority Problem
.W
The problem of the cyclical majority is presented and some new, simulated
results for 3, 4, 5, ..., 40 issues ad 3, 5, 7, ..., 37 judges are reported.
.A
Pomeranz, J. E.
Weil Jr., R. L.
.K
Arrow's paradox, cyclical majority, simulation,
voter's paradox, voting paradox
.I 2078
.T
Representations for Space Planning
.W
Problems involving the arrangement of objects in two-
or three-space where the objective function primarily consists
of derivatives of the distance between objects or their arrangement
are called space planning problems.  The representational
requirements for this problem area are defined and compared with current
computer graphic languages.  Four alternative data structures
that allow automated space planning are described and compared.
.A
Eastman, C. M.
.K
automated design, data structures, computer graphics, computer-aided
design, engineering design, architectural design, robots
.I 2079
.T
On Multiprogramming, Machine Coding, and Computer Organization
.A
Wirth, N.
.I 2080
.T
The Nucleus of a Multiprogramming System
.W
This paper describes the philosophy and structure of a multiprogramming system
that can be extended with a hierarchy of operating systems to suit diverse
requirements of program scheduling and resource allocation.  The system
nucleus simulates an environment in which program execution and input/output
are handled uniformly as parallel, cooperating process
es.  A fundamental set of primitives allows the dynamic creation and control
of a hierarchy of processes as well as the communication among them.
.A
Hansen, P. B.
.K
multiprogramming, operating systems, parallel processes, process concept,
process communication, message buffering, process
hierarchy, process creation, process removal
.I 2081
.T
Some Complete Calculi for Matrices
.W
A matrix calculus is introduced with the intention of developing data structures
suitable for a high level algorithmic language for mathematical programming.
The paper investigates how the special structure of matrices can be described
and utilized for efficient computing by saving memory space and
superfluous operations.  Sequences of Matrices (and sequences of sequences
of matrices) are considered, and matrix operators areext
ended to sequence operators and cumulative operators.  Algorithms
are given which use symbol manipulation of matrix expressions so
as to find the forms best suited for computation.  These forms are
called normal forms.  Several completeness results are obtained
in the sense that for each expression an equivalent expression
in normal form can be found within a specified calculus.
.A
Bayer, R.
Witzgall, C.
.K
complete calculus, data structures, linear
programming, matrix, matrix concatenation,
matrix sequences, programming languages,
sequence operations, symbol manipulation
.I 2082
.T
Syntax-Directed Documentation For PL 360
.W
The language PL 360, together with its phrase structure grammar, is used as a
concrete basis for illustrating an idea called syntax-directed documentation.
This idea is (1) to use the phrase structure of a program to define the
structure of a formal documentation for that program; (2) to use the syntactic
types and identifiers in the resulting structure to trigger the automatic
formation of questions to the programmer, whose answers will
become part of that documentation; and (3) to provide automatic storage
and retrieval facilities so that other programmers who want
to understand or modify the program can access the resulting documentation,
which is cross-indexed in various ways by syntactic types
and objects.  A small PL 360 program, already found
in the literature, is worked out as an example.
.A
Mills, H. D.
.K
documentation, syntax analysis, PL 360, enforced documentation,
indexed documentation, automatic interrogation,
phase structured grammar, syntax-directed documentation, syntax processing
.I 2083
.T
Creation and Control of Internal Data Bases
Under a Fortran Programming Environment
.W
A method is described for the definition of a user's COMMON structure
and the automatic generation of the necessary COMMON, DIMENSION, EQUIVALENCE,
and type declarations for each of the user's routines.  The definition
for the COMMON is contained in an easy to modify form, thus
allowing the control of general communications of data between routines.
The described system has been implemented on the IBM 7094,
CDC 6000 series, and the IBM 360.  The method has proved to be invaluable
for the definition and control of COMMON in many large-scale programs.
.A
DeSalvio, A. J.
Purdy, J. G.
Rau, J.
.K
data base, Fortran, common, common equivalencing,
subroutine communication, data communication
.I 2084
.T
A Note on the Complement of Inherently Ambiguous Context-Free Languages
.A
Maurer, H. A.
.K
ambiguity, inherent ambiguity, complement, context-free language,
Chomsky-language, phrase structure language, production system,
type 2 language, bounded language
.I 2085
.T
Comment on a Paging Anomaly
.A
Dempster, J. R. H.
.K
paging machines, demand paging, replacement algorithm
.I 2086
.T
Another Method of Converting from Hexadecimal to Decimal
.A
Kailas, M. V.
.K
binary-decimal conversion, computer arithmetic categories
.I 2087
.T
A Number System for the Permutations
.A
Pager, D.
.K
permutation, ordering, number, number system, p-number, combinatorial
.I 2088
.T
Netflow (ALgorithm 336 $H))
.A
Bray, T. A.
Witzgall, C.
.K
capacitated network, linear programming, minimum-cost
flow, network flow, out-of-kilter
.I 2089
.T
Prime Number (Algorithm 310 $A1))
.A
Rapp, D. G.
Scott, L. D.
.K
prime numbers, generator
.I 2090
.T
Symbolic Expansion of Algebraic Expressions (Algorithm 377 $R2))
.A
Levine, M. J.
.K
algebra, symbolic algebra, symbolic
multiplication, algebraic distribution,
algebraic multiplication, distribution algorithm,
multiplication algorithm, product
algorithm, polynomial distribution, polynomial expansion
.I 2091
.T
PDEL-A Language for Partial Differential Equations
.W
Conventional computer methods available to solve
continuous system problems characterized by partial
differential equations are very time-consuming and cumbersome.  A
convenient, easy to learn and to use, high level problem oriented
language to solve and study partial differential equation problems
has been designed; a practical translator for the language has also
been designed, and a working version of it has been constructed
for a significant portion of the language.  This Partial Differential
Equation Language, PDEL, is outlined, and the highlights
of the translator are briefly summarized.
.A
Cardenas, A. F.
Karplus, W. J.
.K
problem oriented or digital simulation language,
partial differential equations, translator,
PL/1, preprocessor PL/1, finite difference algorithms
.I 2092
.T
A Deductive Question-Answer for Natural Language Inference
.W
The question-answering aspects of the Protosynthex III pro
totype language processing system are described and exemplified in
detail.  The system is written in LISP 1.5 and operates on the Q-32
time-sharing system.  The system's data structures and their semantic
organization, the deductive question-answering formalism of
relational properties and complex-relation-forming operators, and
the question-answering procedures which employ these features in
their operation are all described and illustrated.  Examples of the
system's performance and of the limitations of its question-answering
capability are presented and discussed.  It is shown that the
use of semantic information in deductive question answering greatly
facilitates the process, and that a top-down procedure which works
from question to answer enables effective use to be made of this
information.  It is concluded that the development of Protosynthex
III into a practically useful system to work with large data
bases is possible but will require changes in both the data
structures and the algorithms used for question answering.
.A
Schwarcz, R. M.
Burger, J. F.
Simmons, R. F.
.K
question answering, natural language, Protosynthex III, LISP,
semantics, artificial intelligence, computational
linguistics, language processing, fact retrieval
.I 2093
.T
A Comparison of Error Improvement Estimates
for Adaptive Trapezoid Integration
.W
Various simple choices of error improvement estimates for the trapezoid
rule are studied to demonstrate a comparison procedure which is
relatively independent of the profusion of adaptive search and stopping
strategies.  Comparisons are based on x^r, `; the inclusion
of the noninteger powers makes this more realistic than the usual polynomial
based comparison.  Behavior near the singularity was found
to be the dominant factor, and a new estimate, based on a constant
curvature assumption and parametric differences, was considered
slightly better than the other choices considered.
.A
Schweikert, D. G.
.K
adaptive integration, error improvement estimate,
trapezoid rule, nonpolynomial error criteria
.I 2094
.T
On an Algorithm for Nonlinear Minimax Approximation
.W
Certain nonlinear minimax approximation problems are characterize
d by properties which permit the application of special algorithms,
mainly based on the exchange algorithms of Remes (1934, 1935), for
their solution.  In this paper the application to problems of this
type of a general nonlinear algorithm due to Osborne and Watson
(1969) is considered.  Examples are given to illustrate that this
algorithm can give satisfactory results and, in particular, can
successfully solve problems which lead to difficulties
with the more conventional specialist method.
.A
Watson, G. A.
.K
minimax approximation, nonlinear approximation, linear programming
.I 2095
.T
Measurements of Segment Size
.W
Distributions of segment sizes measured under routine operating con
ditions on a computer system which utilizes variable sized segments
(the Burroughs B5500) are discussed.  The most striking feature
of the measurements is the large number of small segments-about 60
percent of the segments in use contain less than 40 words.  Although
the results are certainly not installation independent, and although they
are particularly influenced by features of the B5500 ALGOL system, they
should be relevant to the design of new computer systems,
especially with respect to the organization of paging schemes.
.A
Batson, A.
Ju, S.
Wood, D. C.
.K
storage allocation, segmentation, segment sizes, page sizes,
paging, resource allocation, memory allocation, core utilization
.I 2096
.T
Experiments with the M & N Tree-Searching Program
.W
The M & N procedure is an improvement to the mini-max
backing-up procedure widely used in computer program for game-playing
and other purposes.  It is based on the principle that it is
desirable to have many options when making decisions in the face of
uncertainty.  The mini-max procedure assigns to a MAX (MIN) node
the value of the highest (lowest) valued successor to that node.
The M & N procedure assigns to a MAX (MIN) node some function of
the M (N) highest (lowest) valued successors.  An M & N procedure was
written in LISP to play the game of kalah, and it was demonstrated that
the M & N procedure is significantly superior to the mini-max
procedure.  The statistical significance of important conclusions is given.
Since information on statistical significance has often been lacking in papers
on computer experiments in the artificial intelligence field, these experiments
can perhaps serve as a model for future work.
.A
Slagle, J. R.
Dixon, J. K.
.K
artificial intelligence, heuristic program, tree searching,
LISP, kalah, game playing, decision theory,
mini-max backing-up procedure, backing-up procedures
.I 2097
.T
A Program to Teach Programming
.W
The TEACH system was developed at MIT to ease the cost and improve the results
of elementary instruction in programming.  To the student, TEACH offers loosely
guided experience with a  conversational language which was designed with
teaching in mind.  Faculty involvement is minimal.  A term of experience
with TEACH is discussed.  Pedagogically, the system appears to be successful;
straightforward reimplementation will make it economically successful as well.
Similar programs of profound tutorial skill will appear only as the results of
extended research.  The outlines of his research are beginning to become clear.
.A
Fenichel, R. R.
Weizenbaum, J.
Yochelson, J. C.
.K
elementary programming, computer-assisted learning, UNCL, TEACH
.I 2098
.T
t-Test Probabilities (Algorithm 321);
Student's t-Distribution (Algorithm 344)
.A
Hill, G. W.
Loughhead, M.
.K
t-test, Student's t-statistic, distribution function, approximation
.I 2099
.T
Eigenvalues and Eigen vectors of a
Real General Matrix (Algorithm 343 $F))
.A
Knoble, H. D.
.K
norm, characteristic equation, degenerate eigen-system,
diagonalizable matrix, defective matrix
.I 2100
.T
Ortho (Algorithm 127 $F5))
.A
Barrodale, I.
.K
orthogonalization, approximation
.I 2101
.T
Least Squares Fit By f(x) = Acos(Bx+C) (Algorithm 376 $E2))
.A
Spath, H.
.K
nonlinear least squares fit
.I 2102
.T
Fitting Data To One Exponential (Algorithm 375 $E2))
.A
Spath, H.
.K
nonlinear least squares fit
.I 2103
.T
Restricted Partition Generator (Algorithm 374 $A1))
.A
White, J. S.
.K
partitions, restricted partitions, sums of integers, restricted sums
.I 2104
.T
Number of Doubly Restricted Partitions (Algorithm 373 $A1))
.A
White, J. S.
.K
partitions, restricted partitions, sums of integers, restricted sums
.I 2105
.T
An Interactive Computer System Using Graphical Flowchart Input
.W
An interactive computer system operational on a graphical computer terminal is
described.  This system was designed to demonstrate a method of programming by
computer interpretation of a flowchart.  The user draws a description of a
sampled-data system and specifies description is transmitted to a large
scale computer.  The design is simulated, and a graphic representation of the
processed signal is returned to the scope.  A successful design may require
numerous modifications of the original design.  A graphical interactive system
provides an environment to perform this iterative process efficiently and
effectively.
.A
Robins, M. F.
Beyer, J. D.
.K
simulation program, graphical input-output sampled data systems
.I 2106
.T
Computer Education in a Graduate School of Management
.W
Several years of experience have led to the belief that the creative
design and evaluation of management information systems requires
a thorough understanding of the related computer technology.  Concepts
such as paging and priority interrupt systems can best be explained at the
machine language level.  Any machine used for exposition
should fulfill several criteria.  It should: (1) raise as few
spurious issues as possible; (2) allow, without undue effort, the
solution of interesting problems; (3) be capable of exposing all
outstanding issues of significance, capable of exposing all outstanding
issues of significance, within the chosen machine; (4) be
seful for pursuing issues in great depth when appropriate; (5) not
be committed to the equipment provided by any manufacturer; (6) be able to
provide the student with diagnostic aids to a great depth;
(7) allow the student ready access to the machine; (8) be capable
of extension to expose new issues as they come along.  We have
constructed a simulated machine and its associated software which
meets these criteria.  This system, called the PRISM system,
is documented by a primer and a reference manual.
.A
Ness, D. N.
Green, R. S.
Martin, W. A.
Moulton, G. A.
.K
education, simulation, machine language,
management information systems, interpreters
.I 2107
.T
The Quadratic Quotient Method: A Hash
Code Eliminating Secondary Clustering
.W
Secondary clustering as a cause of hash code inefficiency is discussed, and a
new hashing method based on its elimination is presented.  Comparisons with
previous methods are made both analytically and empirically.
.A
Bell, J. R.
.K
hashing, hash code, scatter storage, calculated address, clustering,
search, symbol table, collisions, keys, table look-up
.I 2108
.T
A Variation on Sorting by Address Calculation
.W
The principles of address calculation and merging are combined to yield an
efficient sorting technique. Detailed flowcharts of the most important program
steps are included. The characteristics of the proposed sort are discussed.
.A
Jones, B.
.K
sorting, address calculation, merging, order, sequence creation
.I 2109
.T
The Use of Quadratic Residue Research
.W
A quadratic residue search method has previously been suggested
to avoid the clustering usually encountered when hash address collisions
occur and linear search methods are used.  The search size, because
of the property of quadratic residues, is limited to one half of
the storage table.  It is shown that for some classes of prime numbers
the complement of the set of quadratic residues can easily be determined and
hence the entire table of size p, where p is that prime number, can be searched.
.A
Radke, C. E.
.K
quadratic residue, search method, hash addressing, address
clustering, scatter storage, file searching, file
addressing, hash coding, quadratic search,
random search, storage layout, searching
.I 2110
.T
An Efficient Context-free Parsing Algorithm
.W
A parsing algorithm which seems to be the most efficient general context-free
algorithm known is described.  It is similar to both Knuth's LR(k) algorithm
and the familiar top-down algorithm.  It has a time bound proportional to
n^3 (where n is the length of the string being parsed) in general; it has a
n^2 bound for unambiguous grammars; and it runs in linear time on a large
class of grammars, which seems to include most practical context-free
programming language grammars.  In an empirical comparison it appears
to be superior to the top-down and bottom-up algorithms studied by Griffiths
and Petrick.
.A
Earley, J.
.K
syntax analysis, parsing, context-free grammar,
compilers, computational complexity
.I 2111
.T
Spelling Correction in Systems Programs
.W
Several specialized techniques are shown for efficiently
incorporating spelling correction algorithms in
to compilers and operating systems.  These include the use of syntax
and semantics information, the organization of restricted keyword
and symbol tables, and the consideration of a limited class of spelling
errors.  Sample 360 coding for performing spelling correction
is presented.  By using systems which perform spelling correction,
the number of debugging runs per program has been decreased,
saving both programmer and machine time.
.A
Morgan, H. L.
.K
spelling correction, error correction, debugging, compilers,
operating systems, diagnostics, error detection,
misspelling, lexical analysis systems programming
.I 2112
.T
Translation Equations
.W
Input limited transduction expressions, or translation equations,
are used to describe the syntax and left-context sensitive semantics for
context-free languages.  A formal procedure is given for deriving from
a set of translation equations the specifications for a pushdown translator.
The translator consists of Mealy form finite-state automata interacting
by means of a pushdown stack.  Within the framework described string
recognition and parsing may be treated as special cases of the translation
problem.
.A
Vere, S.
.K
automata, Turing machines, regular expression, transduction
expression, context-free languages, translation, recognizers,
parsing, meta-compilers, pushdown transducer, syntax
directed compilers, finite state automata
.I 2113
.T
The Multistore Parser for Hierarchical Syntactic Structures
.W
A syntactic parser is described for hierarchical concatenation patterns
that are presented to the analyzer in the form of linear strings.  Particular
emphasis is given to the system of "significant addresses" by means
of which processing times for large-scale matching procedures
can be substantially reduced.  The description makes frequent use
of examples taken from the fully operational implementation of the
parser in an experimental English sentence analyzer.  By structuring
an area of the computer's central core storage in such a way
that the individual locations of bytes and bits come to represent the
data involved in the matching procedure, the shifting of information
is reduced to a minimum, and the searching of lists is eliminated
altogether.  The matches are traced by means of binary masks
and the state of single bits determines the operational flow of the
procedure.  The method could be implemented with any interpretive
grammar, provided it can be expressed by the functional classification
of the items composing the input hierarchical structures.
.A
von Glasersfeld, E.
.K
parsing, syntactic analysis, natural-language analysis, linguistic data
processing, computational linguistics, correlational grammar, structure
recognition, pattern recognition, matching procedures, tree-structure
interpretation, machine translation, automatic abstracting
.I 2114
.T
A Formal System for Information Retrieval from Files
.W
A generalized file structure is provided
by which the concepts of keyword, index, record, file, directory,
file structure, directory decoding, and record retrieval are defined
and from which some of the frequently used file structures such
as inverted files, index-sequential files, and multilist files are
derived.  Two algorithms which retrieve records from the generalized file
structure are presented.
.A
Hsiao, D.
.K
attribute-value pair, index, keyword, record, record address,
K-pointer, K-list, file, directory, generalized file
structure, inverted file, index-sequential-file, multilist file,
description, file search, directory search, serial processing of
lists, prime keyword, parallel processing of lists
.I 2115
.T
Fortran Tausworthe Pseudorandom Number Generator
.A
Payne, W. H.
.K
random numbers, pseudorandom numbers, shift register sequences
.I 2116
.T
 Interchange Rolls of Perforated Tape for Information
Interchange* (Proposed American National Standard)
.K
interchange, rolls, perforated tape, tape, information
interchange, directional markers, leaders,
trailers, roll-up tape, 9-track paper tape, dimensions
.I 2117
.T
Representation for Calen
dar Date for Machine-to-Machine Data Interchange*
(Proposed American National Standard)
.K
calendar date, machine-to-machine interchange,
month, year, day, representation coded
.I 2118
.T
An Efficient Algorithm for Sorting with
Minimal Storage (Algorithm 347 $M1))
.A
Griffin, R.
Redish, K. A.
.K
sorting,minimal storage sorting, digital computer sorting
.I 2119
.T
Derivatives (Algorithm 282 $S22))
.A
Gautschi, W.
Klein, B. J.
.K
recursive computation, successive derivatives, error control
.I 2120
.T
An Algorithm to Produce Complex Primes, Csieve (Algorithm 372 $A1))
.A
Dunham, K. B.
.K
primes, complex numbers
.I 2121
.T
Partitions in Natural Order (Algorithm 371 $A1))
.A
McKay, J. K. S.
.K
partitions,number theory
.I 2122
.T
General Random Number Generator (Algorithm 370 $G5))
.A
Butler, E. L.
.K
random number generator, probability density function,
transformation, cumulative density function
.I 2123
.T
Generator of Random Numbers Satisfying the
Poisson Distribution (Algorithm 369 $G5))
.A
Schaffer, H. E.
.K
Poisson distribution, random number generator
.I 2124
.T
Numerical Inversion of Laplace Transforms (Algorithm 368 $D5))
.A
Stehfest, H.
.K
Laplace transform inversion, integral transformations, integral equations
.I 2125
.T
A Note on Minimal Length Polygonal Approximation to a Digitized Contour
.W
A method for extracting a smooth polygonal
contour from a digitized image is illustrated.
The ordered sequence of contour points and the connection graph of
the image are first obtained by a modified Ledley algorithm in one
image scan.  A minimal perimeter polygon subjected to specified constraints
is then chosen as the approximating contour.  The determination of the minimal
polygon can be reduced to a nonlinear programming
problem, solved by an algorithm which takes into account
the weak bonds between variables.  Some examples are presented,
and the corresponding computing times are listed.
.A
Montanari, U.
.K
digitized image, connection tree, minimal polygon,
optimal approximation, nonlinear programming
.I 2126
.T
Experience with an Extensible Language
.W
An operational extensible language system is described.
The system and its base language are appraised with
respect to efficiency, flexibility, and utility
for different categories of users.
.A
Irons, E. T.
.K
programming languages, extensible, compiler, bootstrapping, ambiguity
.I 2127
.T
Natural Language Question-Answering Systems: 1969
.W
Recent experiments in programming natural
language question-answering systems are reviewed
to summarize the methods that have been developed for syntactic, semantic,
and logical analysis of English strings.  It is concluded
that at least minimally effective techniques have been devised for
answering questions from natural language subsets in small scale
experimental systems and that a useful paradigm has evolved to guide
research efforts in the field.  Current approaches to semantic
analysis and logical inference are seen to be effective beginnings
but of questionable generality with respect either to subtle aspects of
meaning or to applications over large subsets of English.
Generalizing from current small-scale experiments to language-processing
systems based on dictionaries with thousands of entries-with
correspondingly large grammars and semantic systems-may entail
a new order of complexity and require the invention and development
of entirely different approaches to semantic analysis and questions answering.
.A
Simmons, R. F.
.K
question-answering, natural language, artificial intelligence,language
processing, fact retrieval, semantics
.I 2128
.T
A Processor Allocation Method for Time-Sharing
.W
A scheduling algorithm is proposed which is intended to minimize changes of
tasks on processors and thereby reduce over-head.  The algorithm also has
application to more general resource allocation problems.  It is implemented
by means of a method for efficiently handling dynamically changing segmented
lists.
.A
Mullery, A. P.
Driscoll, G. C.
.K
time sharing, resource allocation, scheduling algorithms,
monitors, dynamic allocation, processor
allocation, multiprogramming, multiprocessing, time
slicing, scheduling, conversational systems,
interactive systems
.I 2129
.T
Recursive Computation of Certain Derivatives-A
Study of Error Propagation
.W
A brief study is made of the propagation of errors
in linear first-order difference equations.  The
recursive computation of successive derivatives of (e^x)/x
and (cos x)/x is considered as an illustration.
.A
Gautschi, W.
.K
recursive computation, successive derivatives, error propagation
.I 2130
.T
Automatic Segmentation of Cyclic Program Structures
Based on Connectivity and Processor Timing
.W
Time-shared, multiprogrammed, and overlayed batch systems frequently
require segmentation of computer programs into discrete portions.
These program portions are transferred between executable and
peripheral storage whenever necessary; segmentation of program
s in a manner that  reduces the frequency of such transfers is the
subject of this paper.  Segmentation techniques proposed by C. V.
Ramamoorthy are subject to limitations that arise when the preferred
segment size is not compatible with the physical restrictions
imposed by the available computing equipment.  A generalization of
Ramamoorthy's suggestions is made in order to allow their application
when circumstances are other than ideal.
.A
Lowe, T. C.
.K
automatic segmentation, cyclic program structures, loops, paging,
multiprogramming, loaders, assemblers, compilers, time-sharing, program
connectivity
.I 2131
.T
Rapid Computation of Weights of Interpolatory
Quadrature Rules [D1] (Algorithm 417)
.A
Gustafson, S.
.K
divided differences
.I 2132
.T
Rapid Computation of Coefficients of Interpolation
Formulas [E1] (Algorithm 416)
.A
Gustafson, S.
.K
divided differences, Newton's interpolation formula
.I 2133
.T
Algorithm for the Assignment Problem
(Rectangular Matrices) [H] (Algorithm 415)
.A
Bourgeois, F.
Lassalle, J. C.
.K
operations research, optimization theory,
assignment problem, rectangular matrices
.I 2134
.T
An Extension of the Munkres Algorithm for
the Assignment Problem to Rectangular Matrices
.W
The assignment problem, together with Munkres
proposed algorithm for its solution in square
matrices, is presented first.  Then the authors develop
an extension of this algorithm which permits
a solution for rectangular matrices.  Timing results
obtained by using an adapted version of Silver's
Algol procedure are discussed, and a relation between
solution time and problem size is given.
.A
Bourgeois, F.
Lassalle, J.
.K
operations research, optimization theory, assignment
problem, rectangular matrices, algorithm
.I 2135
.T
Rapid Computation of General Interpolation
Formulas and Mechanical Quadrature Rules
.W
Let f have n continuous on a closed interval
[a,b] and let L be a linear functional.  The attempt
is made to approximate L (f) with L (Q) where Q is a polynomial,
approximating f.  Algorithms are developed
for rapid computation of L (Q) for a wide class of
selections of Q which includes the Lagrangian and
Hermitian rules as special cases.
.A
Gustafson, S.
.K
linear functionals, divided differences, Newton's interpolation formula
.I 2136
.T
A Note on "A Modification of Nordsieck's
Method Using an 'Off-Step' Point"
.A
Blumberg, J. W.
Foulk, C. R.
.K
ordinary differential equations, multi-step methods,
predictor, corrector, round-off error, Nordsieck's
method, Gragg-Stetter modification
.I 2137
.T
New LISP Techniques for a Paging Environment
.W
The system described herein employs the block
concept, and that of global and local variables,
in addition to the methods applied in most LISP systems.
 Also, a new means of list representation is
used: "local sequential" for lists created during compilation,
and "block level sequential" for those
created dynamically.  A new garbage collection algorithm
has been introduced to make lists as compact
as possible; partial garbage collection is performed after
each block exit instead of total garbage collection
when storage is exhausted.  The algorithm does not use
the customary flagging procedure.  This combination
of features has eliminated the need for a free list,
and effectively minimizes the number of pages used
at any moment.
.A
Rochfeld, A.
.K
LISP, list processing, paging, virtual memory,
garbage collection, core fragmentation, compact
list structures, block, segment
.I 2138
.T
BLISS: A Language for Systems Programming
.W
A language, BLISS, is described.  This language
is designed so as to be especially suitable
for use in writing production software systems for a
specific machine (the PDP-10): compilers, operating
systems, etc.  Prime design goals of the design are the
ability to produce highly efficient object code,
to allow access to all relevant hardware features of
the host machine, and to provide a rational means
by which to cope with the evolutionary nature of systems
programs.  A major feature which contributes
to the realization of these goals is a mechanism permitting
the definition of the representation of all
data structures in terms of the access algorithm for elements of the structure.
.A
Wulf, W. A.
Russell, D. B.
.K
programming languages, implementation language,
systems programming, data structures
.I 2139
.T
Implementation of the Substring Test by Hashing
.W
A technique is described for implementing the
test which determines if one string is a substring
of another.  When there is low probability that the test
will be satisfied, it is shown how the operation
can be speeded up considerably if it is preceded by
a test on appropriately chosen hash codes of the
strings.
.A
Harrison, M. C.
.K
substring, hashing, subset, signature, information
compression, information retrieval, searching
.I 2140
.T
Retrieval-Update Speed Tradeoffs Using Combined Indices
.W
In a paper in the November 1970 Communications
of the ACM, V. Y. Lum introduced a technique
of file indexing named combined indices.  This technique
permitted decreased retrieval time at the cost
of increased storage space.  This paper examines combined
indices under conditions of file usage with
different fractions of retrieval and update.  Tradeoff
curves are developed to show minimal cost of file
usage by grouping various partially combined indices.
.A
Mullin, J. K.
.K
file organization, combined index files, inverted
files, information retrieval, query, multi-attribute
retrieval, file update
.I 2141
.T
Algorithmic Selection of the Best
Method for Compressing Map Data Strings
.W
The best of a dozen different methods for
compressing map data is illustrated.  The choices
are generated by encoding data strings-sequence of like
codes-by three methods and in four directions.
 Relationships are developed between compression alternatives
to avoid comparing all of them.  The technique
has been used to compress data from forest resource maps,
but is widely applicable to map and photographic
data reduction.
.A
Amidon, E. L.
Akin, G. S.
.K
data compression, map storage, information retrieval,
input/output, run coding, data reduction
.I 2142
.T
Reconstruction of Pictures from Their Projections
.W
There are situations in the natural sciences
and medicine (e.g. in electron microscopy and
X-ray photography) in which it is desirable to estimate the
gray levels of a digital picture at the individual
points from the sums of the gray levels along straight
lines (projections) at a few angles.  Usually,
in such situations, the picture is far from determined
and the problem is to find the "most representative"
picture.  Three algorithms are described (all using
Monte Carlo methods) which were designed to solve
this problem.  The algorithms are applicable in a large
and varied number of fields.  The most important
uses may be the reconstruction of possibly asymmetric particles
from electron micrographs and three-dimensional
X-ray analysis.
.A
Gordon,R.
Herman, G. T.
.K
approximation, biomedical image processing, efficient
encoding, image processing, linear programming,
mathematical programming, Monte Carlo techniques, optimization,
picture compression, picture description,
picture processing, stereology, X-ray analysis
.I 2143
.T
Chebyshev Approximation of Continuous Functions
by a Chebyshev System of Functions [E2] (Algorithm 414)
.A
Bolub, G. H.
Smith, L. B.
.K
approximation, Chebyshev approximation, Remex algorithm
.I 2144
.T
On Accurate Floating-Point Summation
.W
The accumulation of floating-point sums is
considered on a computer which performs t-digit
base B floating-point addition with exponents in the range
-m to M.  An algorithm is given for accurately
summing N t-digit floating-point numbers.  Each of
these N numbers is split into q parts, forming qN
t-digit floating-point numbers.  Each of these is then
added to the appropriate one of n auxiliary t-digit
accumulators.  Finally, the accumulators are added together
to yield the computed sum.  In all, qN+n-1
t-digit floating-point additions are performed.  Under
usual conditions, the relative error in the computed
sum is at most [(t+1)/v]B^(1-t) for some v.  Further,
with an additional q+n-1 t-digit additions, the
computed sum can be corrected to full t-digit accuracy.
 For example, for the IBM/360 (B=16, t=14, M=63,
m=64), typical values for q and n are q=2 and n=32.
In this case, (*) becomes N <= 32,768, and we have
[(t+1)/v]B^(1-t) = 4x16^-13.
.A
Malcolm, M. A.
.K
floating-point summation, error analysis
.I 2145
.T
Automation of Etching-Pattern Layout
.W
HELP (Heuristic Etching-Pattern Layout Program)
is an application program developed to computerize
the tedious and error-prone although vitally important
wiring design of printed circuit boards.  HELP
helps automate a design stage one step closer to production
than logical design.  It can be used to design
wiring patterns of two-layer circuit boards on which
ICs in dual-in-line packages as well as discrete
components such as transistors and resistors have been
placed.  HELP employs two methods of wiring.
One is the heuristic method, which simulates human
approaches to wiring design, and the other is the
theoretically interesting but time-consuming method of
maze-running, based on the Lee's algorithm.  HELP
performs more than 90 percent of required wiring by
the heuristic path with respect to a performance
function for each point-to-point, and point-to-line
connection.  It can bring the number of successful
wiring connections very close to 100 percent.
.A
Aramaki, I.
Kawabata, T.
Kazuhiko, A.
.K
heuristic etching-pattern layout, wiring design of
printed circuit board, maze-running, Lee's algorithm
.I 2146
.T
Optimizing the Polyphase Sort
.W
Various dispersion algorithms for the polyphase
sorting procedure are examined.The optimum
algorithm based on minimizing the total number of unit
strings read is displayed.  The logic of this
algorithm is rather complicated; hence, several other
new dispersion algorithms with more straightforward
logic are presented.  Of the simple dispersion algorithms
discussed, the  Horizontal is best.  It does
approximately one-fourth to one and one-half percent
less reading and writing than most algorithms in
use today.  An additional two and one-fourth to three
percent improvement can be achieved by utilizing
the Modified Optimum Algorithm.  This algorithm is relatively
straightforward, but it requires a fairly
close estimate of the total number of unit strings before the dispersion begins.
.A
Shell, D. L.
.K
sorting, polyphase sorting, dispersion algorithms,
optimum dispersion algorithm, repetition operator
.I 2147
.T
Using Computers in Higher Education:
Past Recommendations, Status, and Needs
.W
Data from a survey conducted with National
Science foundation support, which was published
in December 1970, is reviewed, and it is pointed out
that, with regard to computers in higher education,
national goals stated in the Rosser and Pierce Reports
have not been attained.  Quality was lacking in
hardware or courses in nearly half of the associate
and bachelor's degree programs in data processing,
computer science, etc., offered in 1966-67.  A plea
is made for continuing studies on status and goals
for computing in higher education, improvement of degree
programs, and a national testing laboratory
for educational technology.
.A
Hamblen, J. W.
.K
higher education, computers, degree programs, national
goals, testing laboratory, educational technology
.I 2148
.T
The Composition of Semantics in Algol 68
.W
The main features of Algol 68 are explained
from a semantic point of view.  It is shown how
the language permits the composition of values and actions,
i.e. ultimately programs, from a minimum
set of primitives with a few fundamental recursive rules
of composition.  The associated syntax is briefly
reviewed.  An attempt has been made to obtain a structured
and simple introduction to both Algol 68 and
its orthogonal design.
.A
Branquart, P.
Lewi, J.
Sintzoff, M.
Wodon, P. L.
.K
programming primitives, programming languages,
Algol, semantics, recursive composition, design
of programming languages, data structures
.I 2149
.T
ENTCAF and ENTCRE: Evaluation of Normalized
Taylor Coefficients of an Analytic Function [C5]
(Algorithm 413)
.A
Lyness, J. N.
.K
Taylor coefficients, Taylor series, Cauchy integral,
numerical integration, numerical differentiation,
interpolation, complex variable, complex arithmetic, fast Fourier transform
.I 2150
.T
Concurrent Control with "Readers" and "Writers"
.W
The problem of the mutual exclusion of several
independent processes from simultaneous access
to a "critical section" is discussed for the case where
there are two distinct classes of processes known
as "readers" and "writers."  The "readers" may share
the section with each other, but the "writers" must
have exclusive access.  Two solutions are presented:
one of the case where we wish minimum delay for
the readers; the other for the case where we wish
writing to take place as early as possible.
.A
Courois, P. J.
Heymans, F.
Parnas, D. L.
.K
mutual exclusion, critical section, shared access to resources
.I 2151
.T
User Program Measurement in a Time-Shared Environment
.W
A general discussion of the measurement of
software systems is followed by a description of
a hardware and software scheme for measuring user programs
in a time-shared environment.  The TX-2 computer
at MIT Lincoln Laboratory was used for the implementation
of such a system and the characteristics of
this implementation are reported.  A scenario showing
the system in use is presented.  Finally, it is
shown how other time-sharing systems may provide similar measuring facilities.
.A
Nemeth, A. G.
Rovner, P. D.
.K
operating systems, multiprogramming systems, time-sharing
systems, software measurement, user program
measurement, measurement technology, TX-2 computer,
virtual computers, performance improvement
.I 2152
.T
Display Procedures
.W
Although the use of structured display files
is widespread in interactive computer graphics,
these structures present a number of problems which
tend to restrict their generality and usefulness.
 This paper discusses some of these problems, and suggests an
alternative approach to display system
design which avoids the use of structured display files.
 This technique employs display procedures to
generate information for display.  By including transformations
within calls to these procedures it is
possible both to simplify the specification of pictures
and to speed up their generation.  Display procedures
permit picture elements to be defined conditionally
and also facilitate the processing of inputs from
pointing devices.  The paper is illustrated by examples
from aversion of the EULER language in which
display procedures were implemented.
.A
Newman, W. M.
.K
computer graphics, programming languages, display files
.I 2153
.T
Experiments with an Automated Instructional System for Numerical Methods
.W
A computer system was developed at Purdue
University to teach portions of an undergraduate
course in numerical methods.  Each instructional unit
or lesson is divided into three modes of instruction
which allow the student to press from a computer-controlled
presentation to a student-controlled investigation.
The system is designed as a classroom-independent course
of study, and has been used for two semesters
by students in lieu of conventional classroom instruction.
 Initial measures of effectiveness, student
acceptance, and operational cost are the result of testing
the system independent of instructor intervention.
 The system is operational on a CDC 6500 with teletype terminals.
.A
Oldehoeft, A. E.
Conte, S. D.
.K
computer-assisted instruction, numerical
methods, CAI, instructional systems
.I 2154
.T
Clarification of Fortran Standards-Second Report
.W
In 1966, after four years of effort, Fortran
became the first programming language standardized
in the United States.  Since that initial achievement
study and application of the standard specifications
have revealed the need for maintenance of the standards.
 As the result of work initiated in 1967, an
initial set of clarifying interpretations was prepared and
this clarification was published in Communications
of the ACM in May 1969.  That work has continued and
has resulted in the preparation of this second set
of clarifying interpretations.  The nature of the maintenance
and the new set of corrections to and interpretations
of the standard specifications are reported.
.A
ANSI Subcommittee X3J3
.K
American National Standard, Fortran, Basic Fortran,
programming language, standardization, language
standard specification, language standard maintenance,
language standard clarification, language standard
interpretation, standardization committee
.I 2155
.T
Toward an Understanding of Data Structures
.W
This paper presents a notation and formalism
for describing the semantics of data structures.
 This is based on directed graphs with named edges and
transformations on these graphs.  In addition,
an implementation facility is described which could
be part of a programming language, which allows a
programmer who has expressed the semantics of an algorithm
in terms of the graphs to then specify the
implementation of some of his data structures in order to gain efficiency.
.A
Earley, J.
.K
data structures, graph, implementation,
semantic formalism, programming language
.I 2156
.T
Comment on Cheney's List-Compaction Algorithm
.A
Fenichel, R. R.
.K
LISP, garbage collector, virtual memory,
list processing, storage allocation
.I 2157
.T
Average Binary Search Length for Dense Ordered Lists
.A
Flores, I.
Madpis, G.
.K
searching, binary searching, record retrieval
.I 2158
.T
A Stopping Criterion for the Newton-Raphson Method
in Implicit Multistep Integration Algorithms
for Nonlinear Systems of Ordinary Differential Equations
.A
Liniger, W.
.K
ordinary differential equations, linear multistep
formulas, Newton-Raphson method, stopping criterion
.I 2159
.T
A Note on Best One-Sided Approximations
.A
Phillips, D. L.
.K
best approximation, one-sided approximation,
logarithmic, error, relative error
.I 2160
.T
Canonical Structure in Attribute Based File Organization
.W
A new file structure for attribute based retrieval
is proposed in this paper.  It allows queries
involving arbitrary Boolean functions of the attribute-value
pairs to be processed without taking intersections
of lists.  The structure is highly dependent on the
way in which the file is to be used and is uniquely
determined by the specification of the allowed queries.
 Thus, for example, the structure for retrieval
on the basis of ranges of values of a given attribute would
be very different from one where only retrieval
on the basis of a single value is permitted.  The file
organization being proposed is based on the atoms
of a Boolean algebra generated by the queries.  The desirable
properties claimed for this structure are
proved, and file maintenance questions are discussed.
.A
Wong, E.
Chiang, T. C.
.K
address calculation, atoms of Boolean algebra,
attributes, Boolean functions, Boolean queries,
file organization, information retrieval, inverted
file, key words, multilist, queries, searches
.I 2161
.T
An Algorithm for the Blocks and Cutnodes of a Graph (Corrigendum)
.A
Paton, K.
.I 2162
.T
An Efficient Bit Table Technique for Dynamic
Storage Allocation of 2^n-word Blocks
.W
An efficient bit table technique for dynamic storage
allocation of 2^n-word blocks, which requires
a minimized amount of memory for bookkeeping purposes,
is described. The technique has been tested in
an implementation of the list processing language L^6.
 A number of ideas incorporated in the processor
are also described.
.A
Isoda, S.
Goto, E.
.K
bit table, dynamic storage allocation, buddy
system, L^6, list processing, free storage
.I 2163
.T
Education Related to the Use of Computers in Organizations
.W
The ACM Curriculum Committee on Computer Education
for Management has been carrying out a study
on "Curriculum Development in Management Information
Systems Education in Colleges and Universities"
under a grant from the National Science Foundation.
 This position paper provides a framework for the
study.  Preliminary conclusions are presented on the
need for education in administrative information
systems, and appropriate college curricula and courses
are suggested.  Also, the role of professional
societies and organizations using computers is discussed,
and the plans of the Committee are outlined.
 The initial approach of the Committee has been to describe
the education necessary for the effective
use of computers in organizations, to classify the
positions for which education is required, and to
survey educational programs now available.
.A
Teichroew, D.
.K
education, information analysis, systems design, business data processing
.I 2164
.T
Symbolic Integration: The Stormy Decade
.W
Three approaches to symbolic integration in the
1960's are described.  The first, from artificial
intelligence, led to Slagle's SAINT and to a large
degree to Moses' SIN.  The second, from algebraic
manipulation, led to Manove's implementation and to
Horowitz' and Tobey's reexamination of the Hermite
algorithm for integrating rational functions.  The third,
from mathematics, led to Richardson's proof
of the unsolvability of the problem for a class of functions
and for Risch's decision procedure for the
elementary functions.Generalizations of Risch's algorithm
to a class of special functions and programs
for solving differential equations and for finding
the definite integral are also described.
.A
Moses, J.
.K
integration, symbolic integration, definite integrals, rational functions
.I 2165
.T
General Relativity and the Application of Algebraic Manipulative Systems
.W
The paper describes some applications of symbolic
algebra systems to problems of general relativity
including the derivation of the field equations, the
Petrov classification of a metric, and the solution
of the field equations in the presence of matter in
a simple case.  Attention is drawn to the strictly
algebraic difficulties encountered in this work.
.A
Barton, D.
Fitch, J. P.
.K
symbolic mathematics,nonnumerical mathematics, general
relativity, algebraic manipulation, equation
manipulation
.I 2166
.T
Automated Algebraic Manipulation in Celestial Mechanics
.W
In this paper we consider some of the applications
of automated algebraic manipulation which
have been made in celestial mechanics.  Particular attention
is paid to the use of Poisson series, and
a typical problem in perturbation theory is described.
 The requirements of processors for use in celestial
mechanics are considered and compared with those for general
manipulation packages.  Some future directions
for research using these systems are briefly outlined.
 To illustrate the relative simplicity of the
algorithm required in celestial mechanics, a typical
integration problem is considered in an appendix.
.A
Jefferys, W. H.
.K
series manipulation, automated algebra, celestial mechanics
.I 2167
.T
Algebraic Simplification: A Guide for the Perplexed
.W
Algebraic simplification is examined first from
the point of view of a user who needs to comprehend
a large expression, and second from the point of view
of a designer who wants to construct a useful and
efficient system.  First we describe various techniques
akin to substitution.  These techniques can be
used to decrease thesize of an expression and make it
more intelligible to a user.  Then we delineate
the spectrum of approaches to the design of automatic simplification
capabilities in an algebraic manipulation
system.  Systems are divided into five types.  Each type
provides different facilities for the manipulation
and simplification of expressions. Finally we discuss
some of the theoretical results related to algebraic
simplification.  We describe several positive results
about the existence of powerful simplification
algorithms and the number-theoretic conjectures on which
they rely.  Results about the nonexistence of
algorithms for certain classes of expressions are included.
.A
Moses, J.
.K
algebraic manipulation, algebraic simplification,
canonical simplification
.I 2168
.T
List Tracing in Systems Allowing Multiple Cell-Types
.W
List-processing systems have each allowed the
use of only a single size and configuration of
list cell.  In this paper a system is described which
allows the use of arbitrarily many different sizes
and configurations of list cells, possibly not specified until run time.
.A
Fenichel, R. R.
.K
list-processing, storage allocation, LISP, SLIP, based storage, pointers
.I 2169
.T
The Altran System for Rational Function Manipulation-A Survey
.W
Altran is a complete system for symbolic computation
with rational functions in several variables
with integer coefficients.  It has been designed and
implemented to handle large problems with ease and
efficiency.  Considerable effort has been spent to ensure
a minimum amount of machine dependence in the
implementation, thus permitting the system to be installed
quickly and easily on a variety of computing
machines.  In this paper a brief description of the language,
run time data structures, and implementation
is given.
.A
Hall Jr., A. D.
.K
symbolic algebra, rational function manipulation,
polynomial manipulation, interpreters, translators
.I 2170
.T
Applications of Symbol Manipulation in Theoretical Physics
.W
This paper surveys the applications of symbolic
computation techniques to problems in theoretical
physics.  Particular emphasis is placed on applications
in quantum electrodynamics where the most activity
has occurred.
.A
Hearn, A. C.
.K
symbol manipulation, algebraic simplification,
computational physics, quantum electrodynamics
.I 2171
.T
Solution of Simultaneous Nonlinear Equations
.A
Raduchel, W. J.
.K
nonlinear equations
.I 2172
.T
Graph Plotter [J6] (Algorithm 412)
.A
Cermak, J.
.K
plot, graph, line printer plot
.I 2173
.T
Three Procedures for the Stable Marriage Problem [H] (Algorithm 411)
.A
McVitie, D. G.
Wilson, L. B.
.K
assignment problems, assignment procedures, combinatorics,
discrete mathematics, operations research,
stable marriage problem, university entrance
.I 2174
.T
The Stable Marriage Problem
.W
The original work of Gale and Shapley on an assignment
method using the stable marriage criterion
has been extended to find all the stable marriage assignments.
 The algorithm derived for finding all
the stable marriage assignments is proved to satisfy
all the conditions of the problem.  Algorithm 411
applies to this paper.
.A
McVitie, D. G.
Wilson,L. B.
.K
assignment problems, assignment procedures, combinatorics,
discrete mathematics, operational research,
stable marriage problem, university entrance
.I 2175
.T
Subexpression Ordering in the Execution of Arithmetic Expressions
.W
An arithmetic expression can often be broken
down into its component subexpressions.  Depending
on the hardware environment in which the expression is
to be executed, these subexpressions can be evaluated
in serials, in parallel, or in a combination of these
modes.  This paper shows that expression execution
time can be minimized only if consideration is given to
the ordering of the subexpressions.  In particular,
subexpressions should be executed in order of decreasing
memory and processor time requirements.  This
observation is valid for configurations ranging from
a uniprocessor with an unbuffered main memory to
multiprocessor with a "cache" buffer memory.  If the
number of subexpressions which can be executed in
parallel exceeds the number of available processors,
then execution of some of these subexpressions must
be postponed.  A procedure is given which combines this
requirement with the earlier ordering considerations
to provide an optimal execution sequence.
.A
Ramamoorthy, C. V.
Gonzalez, M. J.
.K
parallel processing, cache, arithmetic expressions,
subexpression ordering, computational trees,
compilers
.I 2176
.T
Buffer Allocation in Merge-Sorting
.W
A fixed buffer allocation for merge-sorting
is presented here which minimizes the number of
input-output operations for a given order of merge.
 When sorting on movable arm disks, the number of
seeks is equal to the number of input-output operations,
and the seek time usually controls the sort
time.  First some standard terminology is introduced.
Then the input buffer allocation method is described,
followed by an analysis of the improvement to be expected
over more conventional allocation.  This analysis
makes use of a particular distribution function.  An
analysis of a completely different distribution
is given which yields similar results.  This suggests
that the results do not depend on a particular
distribution function.  An optimum output buffer size
is also determined.  It is concluded that this
buffering allocation can significantly reduce the time
of merge sorting on movable arm disks when the
input data are not random, and that this output buffer
allocation should be used whether the data is
random or not.
.A
Ferguson, D. E.
.K
file, item, string, merge sort, seek time, gamma distribution function
.I 2177
.T
An Algorithm for the Blocks and Cutnodes of a Graph
.W
An efficient method is presented for finding
blocks and cutnodes of an arbitrary undirected
graph.  The graph may be represented either (i) as an
ordered list of edges or (ii) as a packed adjacency
matrix.  If w denotes the word length of the machine
employed, the storage (in machine words) required
for a graph with n nodes and m edges increases essentially
as 2(m+n) in case (i), or (n^2)/win case
(ii).  A spanning tree with labeled edges is grown,
two edges finally bearing different labels if and
only if they belong to different blocks.  For both representations
the time required to analyze a graph
on n nodes increases as n^G where G depends on the type
of graph, 1 <= G <= 2, and both bounds are attained.
 Values of G are derived for each of several suitable
families of test graphs, generated by an extension
of the web grammar approach.  The algorithm is compared
in detail with that proposed by Read for which
1 <= G <= 3.
.A
Paton, K.
.K
algorithm, block, block-cutpoint-tree, cutnode, fundamental
cycle set, graph, lobe, lobe decomposition
graph, separable, spanning tree, web grammar
.I 2178
.T
A Language Extension for Graph Processing and Its Formal Semantics
.W
A simple programming language "extension,"
Graspe, for processing directed graphs is defined.
 Graspe consists of a type of directed graph data structure
and a set of primitive operations for manipulating
these structures.  Graspe may be most easily implemented
by embedding it in a host language.  Emphasis
is placed both on Graspe itself and on its method of
definition.  Commonly, the definition of a language
involves definition of the syntactic elements and explanation
of the meaning to be assigned them (the
semantics).  The definition of Graspe here is solely in
terms of its semantics; that is, the data structures
and operations are defined precisely but without assignment
of a particular syntactic representation.
 Only when the language is implemented is assignment
of an explicit syntax necessary.  An example of
an implementation of Graspe embedded in Lisp is given as
an illustration.  The advantages and disadvantages
of the definition of a language in terms of its semantics are discussed.
.A
Pratt, T. W.
Friedman, D. P.
.K
graph processing, programming language, formal semantics,
directed graph, Lisp, network, data structure,
flowchart, syntax, language definition
.I 2179
.T
Simple LR(k) Grammars
.W
A class of context-free grammars, called the
"Simple LR(k)" or SLR(k) grammars is defined.
 This class has been shown to include weak precedence
and simple precedence grammars as proper subsets.
 How to construct parsers for the SLR(k) grammars is
also shown.  These parser-construction techniques
are extendible to cover all of the LR(k) grammars of
Knuth; they have been implemented and by direct
comparison proved to be superior to precedence techniques,
not only in the range of grammars covered,
but also in the speed of parser construction and
in the size and speed of the resulting parsers.
.A
DeRemer, F. L.
.K
context-free grammar, LR(k) grammar, precedence
grammar, syntactic analysis, parsing algorithm,
parser, finite-state machine, deterministic pushdown automaton
.I 2180
.T
A Programmer Training Project
.W
A project is described whose purpose is to train
selected black residents of the Albany-Schenectady
area in computer programming and arrange for jobs for
them in the computer field. Both the organization
and curriculum of the course are discussed.
.A
Bernstein, A. J.
.K
programmer training, job opportunities, Fortran
.I 2181
.T
The State of Computer Oriented Curricula in Business Schools 1970
.W
The ACM Committee on Computer Education for Management,
supported by a National Science Foundation
Grant, is established to appraise the state of the art
and to develop a series of recommendations for
improving computer education for management.  To provide
the Committee with material for its study of
curricular needs, five regional meetings in the United
States were held in 1970, at each of which a broad
cross section of invited academicians and practitioners
considered the state of curricula in business
schools.  Three topics were covered: curricula for
the general manager; computer-related material in
required and functional courses; and curricula for students
concentrating on computer-based information
systems.  An analysis of the minutes of the meetings
revealed a common set of experiences which raised
similar pedagogic and economic issues.  This presentation
gives a summary of the discussions; a condensation
of the pedagogic and substantive concerns raised; and
consideration of the resource allocation issues
involved.  Preliminary to the Committee's recommendations
for improving computer education for management,
this report has been prepared to provide the participants
and the administrators of their institutions
with background information for the ongoing task of course
development.  Chairman of the ten-man Committee
is Daniel Teichroew (The University of Michigan).
.A
McKenney, J. L.
Tonge, F. M.
.K
university programs, management education, curriculum
design, business administration curricula,
graduate business school resource planning
.I 2182
.T
Interrupt Driven Programming
.A
Zelkowitz, M.
.K
interrupts, supervisors, monitors, debugging, parallel
processing, associative memories, microprogramming
.I 2183
.T
Binary Summation
.A
Walker, R. J.
.K
summation, binary summation, floating-point addition, round-off errors
.I 2184
.T
On the Meaning of Names in Programming Systems
.W
It is assumed that there is a similarity of
function between the data names of a programming
language and the file names of an operating system.
 The two functions are discussed in terms of the
same basic concepts in order to identify the extent
to which they overlap. It is suggested that there
is some similarity between the idea of a file directory
and a storable object of type context.  Manipulations
with contexts are then discussed at length.  It is noted
that there is a simple extension of Church's
Lambda notation that deals nicely with these ideas of
context manipulation.  Whereas a function can be
regarded as the abstraction based upon the first two terms of
the expression Lambda(name list)(expression)(value list),
it is found that a context can be viewed as an abstraction
based upon the first two terms in the equivalent
expression Mu(name list)(value list)(expression).
.A
Fraser, A. G.
.K
file, operating system, programming language, functions,
names, context, file directory, file dictionary,
lambda calculus, theory of programming
.I 2185
.T
A Note on Compiling Fixed Point Binary Multiplications
.W
An algorithm is developed for compiling, as
a sequence of shifts, additions,and subtractions,
many fixed point binary multiplications involving a
constant.  The most significant characteristics of
the algorithm are the simplicity of the test which
determines if the algorithm should be applied and
the degree to which it "suggests" efficient object code.
.A
Glaswin, H. T.
.K
compiling multiplications, fixed point arithmetic
.I 2186
.T
Numerical Properties of the Ritz-Trefftz Algorithm for Optimal Control
.W
In this paper the Ritz-Trefftz algorithm is applied
to the computer solution of the state regulator
problem.  The algorithm represents a modification of
the Ritz direct method and is designed to improve
the speed of solution and the storage requirements to
the point where real-time implementation becomes
feasible.  The modification is shown to be more stable
computationally than the traditional Ritz approach.
 The first concern of the paper is to describe the
algorithm and establish its properties as a valid
and useful numerical technique.  In particular such useful
properties as definiteness and reasonableness
of condition are established for the method.  The second
part of the paper is devoted to a comparison
of the new techniques with the standard procedure of
numerically integrating a matrix Riccati equation
to determine a feedback matrix.  The new technique is
shown to be significantly faster for comparable
accuracy.
.A
Bosarge Jr., W. E.
Johnson, O. G.
.K
splines, regulator problem, control theory, numerical analysis
.I 2187
.T
Computer Science: A Conceptual Framework for Curriculum Planning
.W
Two views of computer science are considered:
a global view which attempts to capture broad
characteristics of the field and its relationships to
other fields, and a local view which focuses on
the inner structure of the field.  This structure is presented
in terms of the kinds of knowledge, problems,
and activities that exist within the discipline, as
well as the relations between them.  An approach
to curriculum planning in computer science is presented
which is guided by the structure of the field,
by the fact that change is an important feature of the
situation, and by the expectation that computer
science will continue to increase its working contacts with other disciplines.
.A
Amarel, S.
.K
computer science, curriculum planning, education
.I 2188
.T
An Approach to the Optimum Design of Computer Graphics Systems
.W
Display system designers are faced with the
difficult task of selecting major subsystems in
an intelligent way.  Each subsystem is chosen from large
numbers of alternatives; the selection is based
on considerations such as system response time, system
cost, and the distribution of data storage and
processing between the graphics processor and its supporting
data processing system.  The work reported
here develops an objective, quantitative design procedure
and helps give a better understanding of now
to  configure display systems.  This is accomplished by
means of a mathematical model of a computer driven
graphics system.  The parameters of the model are functions
of the capabilities of the graphics hardware
and of the computational requirements of the graphics application.
 The model can be analyzed using numerical
queueing analysis or simulation to obtain an average
response time prediction.  By combining the model
with an optimization, the best graphics system configuration,
subject to a cost constraint, is found
for several applications.  The optimum configurations
are in turn used to find general display system
design guidelines.
.A
Foley, J. D.
.K
design guidelines, graphic display systems, mathematical
model, optimum system design, queueing
model
.I 2189
.T
Generation of Rosary Permutations Expressed in Hamiltonian Circuits
.W
Systematic generation of a specific class
of permutations fundamental to scheduling problems
is described.  In a nonoriented complete graph with
n vertices, Hamitonian circuits equivalent to .5(n
- 1)! specific permutations of n elements, termed rosary
permutations, can be defined.  Each of them
corresponds to two circular permutations which mirror-image
each other, and is generated successively
by a number system covering 3*4*...*(n-1) sets of edges.
 Every set of edges {E[k]}, 1 <= E[k] <= k,
3 <= k <= (n-1) is determined recursively by constructing
a Hamiltonian circuit with k vertices from
a Hamiltonian circuit with k-1 vertices, starting with
the Hamiltonian circuit of 3 vertices.  The basic
operation consists of transposition of a pair of adjacent
vertices where the position of the pair in
the permutation is determined by {E[k]}.  Two algorithms
treating the same example for five vertices
are presented.  It is very easy to derive all possible n!
permutations  from the .5(n - 1 )! rosary permutations
be cycling the permutations and by taking them in the
reverse order-procedures which can be performed
fairly efficiently by computer.
.A
Harada, K.
.K
permutation, graph theory, scheduling, combinatorial algebra
.I 2190
.T
Function Minimization
.A
House, F. R.
.I 2191
.T
ALGORITHM 410 Partial Sorting [M1]
.A
Chambers, J. M.
.K
sorting, partial sorting order statistics
.I 2192
.T
Another Recursion Induction Principle
.W
An inductive method for proving things about
recursively defined functions is described.  It
is shown to be useful for proving partial functions equivalent
and thus applicable in proofs about interpreters
for programming languages.
.A
Morris Jr., J. H.
.K
recursion, induction, correctness, proofs, compiler correctness
.I 2193
.T
On Implementation of Label Variables
.W
Variables of label mode are conventionally
implemented with a technique which fails to trap
certain programming errors.  Fine-grained calendar clocks
have recently become available; these allow
implementation of label variables via a new technique
which traps all programming errors of this variety.
.A
Fenichel, R. R.
.K
labels, compiler, interpreter, go to, transfer
.I 2194
.T
How To Keep the Addresses Short
.W
An algorithm is presented for minimizing the
sum of the lengths of the blocks of coding produced
by an assembler or compiler when (1) the length of
each computer instruction is assumed to be either
"long" or "short" ("long," if the memory location addressed
is more than a predetermined distance from
the current location; "short," otherwise), and (2)
there are blocks of instructions whose beginnings
(origins) are separated by prespecified amounts. For example,
some computers permit either 8-bit addressing
(interpreted relative to the location counter) or full
16-bit addressing of all of memory.  When assembling
or compiling two or more blocks of instructions which
have many mutual references in such a computer,
there is no simple iterative procedure for keeping
as many of the addresses short as possible.  This
paper demonstrates that a wide class of problems of
this type can be formulated as covering problems
solvable by means of elementary arithmetic operations
on the column vectors of a ternary matrix.
.A
Richards, D. L.
.K
addressing, assembler, covering problem, integer
programming, variable-length addressing
.I 2195
.T
On the Optimal Detection of Curves in Noisy Pictures
.W
A technique for recognizing systems of lines
is presented.  In this technique the heuristic
of the problem is not embedded in the recognition algorithm
but is expressed in a figure of merit.
A multistage decision process is then able to recognize
in the input picture the optimal system of lines
according to the given figure of merit.  Due to the
global approach, greater flexibility and adequacy
in the particular problem is achieved.  The relation
between the structure of the figure of merit and
the complexity of the optimization process is then discussed.
 The method described is suitable for parallel
processing because the operations relative to each
state can be computed in parallel, and the number
of stages is equal to the length N of the curves (or
to log2 N if the approximate method is used).
.A
Montanari, U.
.K
picture processing, picture recognition, picture
description, curve detection, line detection,
edge detection,optimal detection, heuristic methods,
global recognition, parallel processing, dynamic
programming, interaction graph, secondary optimization problem
.I 2196
.T
A Man-Machine Approach Toward Solving the Traveling Salesman Problem
.W
The traveling salesman problem belongs to an
important class of scheduling and routing problems.
 It is also a subproblem in solving others, such as
the warehouse distribution problem.  It has been
attacked by many mathematical methods with but meager
success.  Only for special forms of the problem
or for problems with a moderate number of points can
it be solved exactly, even if very large amounts
of computer time are used.  Heuristic procedures have
been proposed and tested with only slightly better
results.  This paper describes a computer aided heuristic
technique which uses only a modest amount of
computer time in real-time to solve large (100-200)
point problems.  This technique takes advantage of
both the computer's and the human's problem-solving
abilities.  The computer is not asked to solve the
problem in a brute force way as in many of today's heuristics,
but it is asked to organize the data for
the human so that the human can solve the problem easily.
 The technique used in this paper seems to
point to new directions in the field of man-machine interaction
and in the field of artificial intelligence.
.A
Krolak, P.
Felts, W.
Marble, G.
.K
heuristic procedures, computer-aided heuristic technique,
man-machine interaction, artificial intelligence,
assignment problem, mask of the assignment, rubber band
tour generator, interaction process, traveling
salesman problem
.I 2197
.T
The Merit of Regional Computing Networks
.W
One of the suggested means for stimulating the
spread of computing capabilities in institutions
of higher learning is through the construction of regional
computing networks.  One such network has
been constructed in the San Francisco Bay Area by Stanford
University.  This paper reports upon the lessons
learned from the operation of the network over the past
two years.  A major impact of the network was
not so much the computer power delivered to the schools
as the awakening of computing awareness and the
fostering of capability development at these schools. The
expertise and assistance from the central facility
as well as the sharing of ideas among the participants
were other important benefits.  Both the quality
and variety of services provided by the central facility
were found to play a key role in the effectiveness
of the network.  A regional network brings many benefits
and should not be judged as a purveyor of raw
computer power alone.
.A
Nielsen, N. R.
.K
computer sharing, computer utility, cooperative networks,
curriculum development, educational computing,
network computing, regional computing networks,
remote computing, shared computing
.I 2198
.T
Introduction to "Feature Analysis of
Generalized Data Base Management Systems"
.W
This paper is a separately published introduction
to a main report which analyzes the features
of generalized data base management systems.  This introduction
gives a review of the current state of
the art in these systems and discusses the differences
and similarities between capabilities found in
host language systems and those found in self-contained
systems.  After some discussion of the problems
of data independence and binding,the four user levels
are identified and described.  Technical problems
facing future designers are described.  The first of
these is that of handling existing stored data and
the next is that of providing more complex data structures
than those already available in conventional
programming languages.  The problem of high level interrogation
and update functions acting on network
structures is mentioned, followed by a discussion of the
problem of catering to a high volume of transactions
initiated from terminals by parametric users-the lowest
level of user.  The use of Cobol as a basis for
further development work is considered at some length
with respect to data structures, host language
capabilities, and self-contained capabilities.  This
section also assesses the effect of the Data Base
Task Group proposals.  The final section outlines the
ten major topics in the main body of the full report.
.A
Codasyl Systems Committee
.K
data base management systems, programming languages,
data structures, storage structures, information
retrieval, transaction processing
.I 2199
.T
A Sparse Matrix Package (Part I) [F4] (Algorithm 408)
.A
McNamee, J. M.
.K
matrix, sparse matrix, matrix manipulation
.I 2200
.T
On Complement Division
.W
The division algorithm theorem is expressed
in a form that permits it to serve as the basis
for devising division operations that produce both quotient
and remainder in complement form.  Algorithms
for division yielding complement results are derived
for numbers represented in any base greater than
one.  Both radix and radix-less-one complementation schemes
are considered.  The binary form of the algorithms
thus includes both two's and one's complement implementation.
 The problem of quotient overflow for complement
results is dealt with as is that of selecting an appropriate
form of the remainder condition for complement
division.
.A
Stein, M. L.
Munro, W. D.
.K
division algorithm, complement arithmetic, complement
division, one's complement arithmetic, two's
complement arithmetic
.I 2201
.T
Animator: An On-Line Two-dimensional Film Animation System
.W
Animator is a computer animation system which
was designed to overcome some of the inherent
disadvantages associated with conventional computer animation
techniques.The DEC-338 serves as an input
terminal for movie making, allowing the trial and error
design of picture sequences in a conversational
mode.  During all stages on the system input elements
(light pen, pushbuttons, and teletype) is maintained.
 At the user's request, this record is sent to the IBM
360/75 where the S-D 4020 instructions necessary
to produce the same sequence of pictures can be generated.
 It is anticipated that one of the primary
contributions of Animator will be the provision of a
facility which will allow any professor to produce
his own expository film strips.
.A
Talbot, P. A.
Carr III, J. W.
Coulter Jr., R. R.
Hwang, R. C.
.K
computer graphics, computer animation, on-line
systems, two-dimensional languages, CRT, microfilm
recorder
.I 2202
.T
Dynamic Microprogramming: Processor Organization and Programming
.W
A dynamically microprogrammed processor is characterized
by a small (4^k 64-bit word) read-write
"micro" storage.  The access time of this storage is
similar to the cycle time of the machine (50-100
nsec).  This microstorage is used to contain both data
and subroutines.  The (micro) instructions in
such a processor differ from the conventional in that
they perform only purely combinatorial operations;
sequencing is under the control of the microinstruction.
The presence of the read-write microstorage
permits a more flexible assignment of resources than the
read-only storage.  In particular, the processor
developed in this paper stresses the simultaneous operation
(within the microinstruction) of the adder,
shifter, masker, and testing facilities of the processor.
 A microassembly language is developed and
the overhead involved in subroutine linkages is analyzed.
 The efficiency of a flexible software linkage
scheme is examined as to its overhead for various subroutine
characteristics.  Finally, three examples
of problem-oriented programming are considered and the
resulting coding is compared against a System/360
assembly language version, with the technology normalized.
.A
Tucker, A. B.
Flynn, M. J.
.K
microprogramming,read-write microstorage,
subroutine linkage, execution speed
.I 2203
.T
Key-to-Address Transform Techniques: A Fundamental
Performance Study on Large Existing Formatted
Files
.W
The results of a study of eight different
key-to-address transformation methods applied to
a set of existing files are presented.  As each method
is applied to a particular file, load factor and
bucket size are varied over a wide range.  In addition,
appropriate variables pertinent only to a specific
method take on different values.  The performance of
each method is summarized in terms of the number
of accesses required to get to a record and the number
of overflow records created by a transformation.
 Peculiarities of each method are discussed.  Practical
guidelines obtained from the results are stated.
 Finally, a proposal for further quantitative fundamental study is outlined.
.A
Lum, V. Y.
Yuen, P. S. T.
Dodd, M.
.K
hashing, hashing techniques, hashing methods, hash
coding, keys, key transformation, key-to-address
transformation, direct addressing, direct access method,
randomizing, random access,file addressing,
file organizations, file structures, scatter storage,
search, collisions, clusters, information retrieval
.I 2204
.T
Program Development by Stepwise Refinement
.W
The creative activity of programming-to be distinguished
from coding-is usually taught by examples
serving to exhibit certain techniques.  It is here considered
as a sequence of design decisions concerning
the decomposition of tasks into subtasks and of data
into data structures.  The process of successive
refinement of specifications is illustrated by a short
but nontrivial example, from which a number of
conclusions are drawn regarding the art and the instruction of programming.
.A
Wirth, N.
.K
education in programming, programming
techniques, stepwise program construction
.I 2205
.T
DIFSUB for Solution of Ordinary Differential
Equations [D2] (Algorithm 407)
.A
Gear, C. W.
.K
differential equations, stiff differential equations
.I 2206
.T
Exact Solution of Linear Equations Using
Residue Arithmetic [F4] (Algorithm 406)
.A
Howell, J.
.K
residue arithmetic, symmetric residue, modulus,
mixed-radix representation, symmetric mixed-radix
representation, mixed-radix conversion, prime number,
linear equations, Gaussian elimination, matrix
inversion, determinant, adjoint matrix, ill-condition
.I 2207
.T
The Automatic Integration of Ordinary Differential Equations
.W
An integration technique for the automatic
solution of an initial value problem for a set of
ordinary differential equations is described.  A criterion
for the selection of the order of approximation
is proposed.  The objective of the criterion is to increase
the step size so as to reduce solution time.
An option permits the solution of "stiff" differential
equations.  A program embodying the techniques
discussed appears in Algorithm 407.
.A
Gear, C. W.
.K
differential equations, stiff equations,
integration, step control, order control
.I 2208
.T
Storage Utilization in a Memory Hierarchy When Storage
Assignment Is Performed by a Hashing Algorithm
.W
The utilization of storage is studied in a two-level
memory hierarchy.  The first storage level,
which is the fast store, is divided into a number of
storage areas.  When an entry is to be filed in
the hierarchy, a hashing algorithm will attempt to
place the entry into one of these areas.  If this
particular area is full, then the entry will be placed
into the slower second-level store, even though
other areas in the first-level store may have space
available.  Given the N entries have been filed in
the entire hierarchy, an expression is derived for the
expected number of entries filed in the first-level
store.This expression gives a measure of how effectively
the first-level store is being used.  By means
of examples, storage utilization is then studied as a
function of the hashing algorithm, the number of
storage areas into which the first-level store is divided
and the total size of the first-level store.
.A
Williams, J. G.
.K
hashing algorithms, memory allocation, memory hierarchy,
memory utilization, storage allocation,
storage hierarchy, storage utilization
.I 2209
.T
A Scheduling Algorithm for a Computer Assisted Registration System
.W
This paper presents the scheduling algorithm
used in the Computer Assisted Registration System
at the University of Tennessee.  Notation is defined and
the logic of the algorithm necessary to implement
educational policy is described.  Results from
the first term's implementation are presented.
.A
Winters, W. K.
.K
computer assisted registration, scheduling algorithm, timetable
.I 2210
.T
Toward Automatic Program Synthesis
.W
An elementary outline of the theorem-proving
approach to automatic program synthesis is given,
without dwelling on technical details.  The method is
illustrated by the automatic construction of both
recursive and iterative programs operating on natural
numbers,lists, and trees,  In order to construct
a program satisfying certain specifications a theorem
induced by those specifications is proved, and
the desired program is extracted from the proof.  The
same technique is applied to transform recursively
defined functions into iterative programs, frequently
with a major gain inefficiency.  It is emphasized
that in order to construct a program with loops or with
recursion, the principle of mathematical induction
must be applied. The relation between the version of
the induction rule used and the form of the program
constructed is explored in some detail.
.A
Manna, Z.
Waldinger, R. J.
.K
artificial intelligence, answer extraction, automatic
program synthesis, mathematical induction
principle, problem solving, theorem proving
.I 2211
.T
Scanned-Display Computer Graphics
.W
A television-like scanned-display system has
been successfully implemented on a Honeywell DDP-224
computer installation.  The scanned image is stored
in the core memory of the computer, and software
scan conversion is used to convert the rectangular coordinates
of a point to the appropriate word and
bit in an output display array in core storage.  Results
thus far indicate that flicker-free displays
of large amounts of data are possible with reasonably
fast graphical interaction.  A scanned image of
size 240 X 254 points is displayed at a 30 frame-per-second rate.
.A
Noll, A. M.
.K
computer graphics, scanned-display, scan conversion, raster displays
.I 2212
.T
F-DISTRIBUTION
.A
Tolman, H.
.K
Fisher's F-distribution, Student's t-distribution
.I 2213
.T
Roots of Matrix Pencils: The Generalized
Eigenvalue Problem [F2] (Algorithm 405)
.A
Dell, A. M.
Weil, R. L.
Thompson, G. L.
.K
eigenvalues, matrix roots, pencil roots
.I 2214
.T
Complex Interval Arithmetic
.W
Complex interval arithmetic is defined using
real interval arithmetic.  Complex interval division
is defined so as to assure smallest possible resulting intervals.
.A
Rokne, J.
Lancaster, P.
.K
real intervals, real interval arithmetic,
complex intervals, complex interval arithmetic
.I 2215
.T
Application of Game Tree Searching Techniques
to Sequential Pattern Recognition
.W
A sequential pattern recognition (SPR) procedure
does not test all the features of a pattern
at once.  Instead, it selects a feature to be tested.  After
receiving the result of that test, the procedure
either classifies the unknown pattern or selects another
feature to be tested, etc.  Medical diagnosis
is an example of SPR.  In this paper the authors suggest
that SPR be viewed as a one-person game played
against nature (chance).  Virtually all the powerful techniques
developed for searching two-person, strictly
competitive game trees can easily be incorporated either
directly or by analogy into SPR procedures.
 In particular, one can incorporate the "mini average
backing-up procedure" and the "gamma procedure,"
which are the analogues of the "minimax backing-up procedure"
and the "alpha-beta procedure," respectively.
 Some computer simulated experiments in character recognition
are presented.  The results indicate that
the approach is promising.
.A
Slagle, J. R.
Lee, R. C. T.
.K
sequential pattern recognition, game tree searching,
game against nature, gamma procedure, mini average
backing-up procedure, dynamic programming, branch-and-bound
approach, optimal solution
.I 2216
.T
On the Probability Distribution of the Values of Binary Trees
.W
An integral equation is derived for the generating
function for binary tree values, the values
reflecting sorting effort. The analysis does not assume
uniformly distributed branching ratios, and
therefore is applicable to a family of sorting algorithms
discussed by Hoare, Singleton, and van Emden.
 The solution to the integral equation indicates that
using more advanced algorithms in the family makes
only minor reductions in the expected sorting effort,
but substantially reduces the variance in sorting
effort.  Statistical tests of the values of several
thousand trees containing up to 10,000 points have
given first, second, and third moments of the value distribution
function in satisfactory agreement with
the moments computed from the generating function.  The
empirical tests, as well as the analytical results,
are in agreement with previously published results for the
first moment in the cases of uniform and nonuniform
distribution of branching ratio, and for the second moment
in the case of uniform distribution of branching
ratio.
.A
Hurwitz Jr., H.
.K
binary trees, sorting, statistical analysis
.I 2217
.T
Experiments in Automatic Learning for a Multipurpose Heuristic Program
.W
An automatic learning capability has been developed
and implemented for use with the MULTIPLE
(MULTIpurpose Program that LEarns) heuristic tree-searching
program, which is presently being applied
to resolution theorem-proving in predicate calculus.
MULTIPLE's proving program (PP) uses two evaluation
functions to guide its search for a proof of whether
or not a particular goal is achievable.  Thirteen
general features of predicate calculus clauses were created
for use in the automatic learning of better
evaluation functions for PP.  A multiple regression
program was used to produce optimal coefficients
for linear polynomial functions in terms of the features.
 Also, automatic data-handling routines were
written for passing data between the learning program
and the proving program, and for analyzing and
summarizing results.  Data was generally collected for
learning (regression analysis) from the experience
of PP.  A number of experiments were performed to test
the effectiveness and generality of the learning
program. Results showed that the learning produced dramatic
improvements in the solutions to problems
which were in the same domain as those used for collection
learning data.  Learning was also shown to
generalize successfully to domains other than those used
for data collection.  Another experiment demonstrated
that the learning program could simultaneously improve
performance on problems in a specific domain and
on problems in a variety of domains.  Some variations
of the learning program were also tested.
.A
Slagle, J. R.
Farrell, C. D.
.K
learning, theorem-providing, heuristic, automatic
learning, self-modifying,tree-searching, artificial
intelligence, problem-solving, adaptive, LISP, multiple regression, resolution
.I 2218
.T
An Analysis of Some Time-Sharing Techniques
.W
The effectiveness of certain time-sharing techniques
such as program, relocation, disk rotational
delay minimization, and swap volume minimization is
investigated.  Summary data is presented, and the
findings are discussed.  The vehicle for this investigation
was a SIMULA based simulation model reflecting
an early framework for a planned Burroughs B6500 time-sharing
system.  Inasmuch as the B6500 system is
based upon the use of variable sized segments and a
dynamic overlay procedure, data is also presented
which provides some indication of the effectiveness of this
type of organization in a time-sharing environment.
 The design characteristics and operational capabilities
of the simulation model are also described.
.A
Nielsen, N. R.
.K
B6500, bulk core usage, operating system model, relocation,
rotational delay minimization, simulation,
swap volume minimization, system simulation, time-sharing
.I 2219
.T
A Policy-Driven Scheduler for a Time-Sharing System
.W
The service received by a process from a time-sharing
operating system can be characterized
by a resource count SUM{w[i]R[ij]} where R[ij] is the
number of units of service received by process
i from resource i and w[i] is the cost per unit of the
service.  Each class of users can be characterized
by a policy function which specifies the amount of service
a user who belongs to this class should receive
as a function of time.  Priority changes dynamically
as a function of the difference between the service
promised to the user by the policy function and the service
he actually receives.  A scheduling and swapping
algorithm which keeps the resource count of each process
above its policy function will provide the specified
level of service.  Overhead can be reduced by avoiding
swaps of process which have received at least
his level of service.  The algorithm has been implemented
in a general purpose operating system, and
it has provided significantly better service to interactive
and to batch jobs than the previous scheduler.
.A
Bernstein, A. J.
Sharp, J. C.
.K
scheduler, time-sharing, operating system,
resource allocation and swapping
.I 2220
.T
Conversion of Limited-Entry Decision Tables to Computer
Programs-A Proposed Modification to Pollack's
Algorithm
.W
Pollack has proposed an algorithm for converting
decision tables into flowcharts which minimize
subsequent execution time when compiled into a computer
program.  Two modifications of this algorithm
are proposed.  The first relies on Shannon's noiseless
coding theorem and the communications concept
of entropy but does not completely test the ELSE Rule.
 The second modification completely tests the
ELSE Rule but results in more executions than the first modification.
 Both modifications result in modification
guarantees a globally optimal solution.
.A
Shwayder, K.
.K
coding, decision table, entropy, information
theory, noiseless channel, sorting
.I 2221
.T
Comment on the Conversion of Decision Tables to Computer Programs
.A
Pollack, S. L.
.K
decision tables, diagnostic aids, system analysis, business applications
.I 2222
.T
Comment on London's Certification of Algorithm 245
.A
Redish, K. A.
.K
proof of algorithms, debugging, certification,
metatheory,  sorting, in-place sorting
.I 2223
.T
Minit Algorithm For Linear Programming (Algorithm 222 [H])
.A
Kolm, A.
Dahlstrand, T.
.K
linear programming, dual simplex method, primal problem, dual problem
.I 2224
.T
Complex Gamma Function [S14] (Algorithm 404)
.A
Lucas Jr., C. W.
Terrill, C. W.
.K
gamma function, poles of gamma function, Stirling's
asymptotic series, recursion formula, reflection
formula
.I 2225
.T
Circular Integer Partitioning [A1] (Algorithm 403)
.A
Coleman, M. W.
Taylor, M. S.
.K
partitions, combinatorics, statistical design of experiments
.I 2226
.T
Further Evidence for the Analysis of Algorithms
for the Zero-One Programming Problem
.W
The purpose of this note is to report computational
experience additional to that recently
summarized by Gue et al, with two algorithms for the
zero-one linear programming problem.  An error in
Gue's paper is corrected.  The utility of one of
the algorithms as a suboptimizer is indicated.
.A
Proll, L. G.
.K
operations research, integer programming, zero-one variables, algorithms
.I 2227
.T
Proof of a Program: FIND
.W
A proof is given of the correctness of the
algorithm "Find."  First, a informal description
is given of the purpose of the program and the method
used.  A systematic technique is described for
constructing the program proof during the process of coding
it, in such a way as to prevent the intrusion
of logical errors.  The proof of termination is treated
as a separate exercise.  Finally, some conclusions
relating to general programming methodology are drawn.
.A
Hoare, C. A. R.
.K
proofs of programs, programming methodology, program
documentation, program correctness, theory
of programming
.I 2228
.T
Comments on Prevention of System Deadlocks
.W
Habermann's method of deadlock prevention is
discussed, where deadlock is defined as a system
state from which resource allocations to certain processes
are not possible.  It is shown that the scheduler
may introduce "artificial" deadlocks which Habermann's
method does not prevent.  Permanent blocking is
the situation where certain processes never receive their
resource requests.  It is shown that deadlock
prevention does not necessarily eliminate permanent blocking.
 A method of preventing permanent blocking
is given.
.A
Holt, R. C.
.K
multiprogramming, time-sharing, scheduling, resource
allocation, deadlock, lockout, deadly embrace,
knotting
.I 2229
.T
Construction of Rational and Negative Powers of a Formal Series
.W
Some methods are described for the generation
of fractional and negative powers of any formal
series, such as Poisson series or Chebyshev series.  It
is shown that, with the use of the three elementary
operations of addition, subtraction, and multiplication,
all rational (positive and negative) powers
of a series can be constructed.  There are basically two
approaches: the binomial theorem and the iteration
methods.  Both methods are described here, and the relationship
between them is pointed out.  Some well-known
classical formulas are obtained as particular cases,
and it is shown how the convergence properties of
these formulas can be improved with very little additional
computations.  Finally, at the end of the
article, some numerical experiments are described
with Chebyshev series and with Fourier series.
.A
Brucke, R. A.
.K
series expansion, series inversion, root extraction,
binomial theorem, Newton iterations, Chebyshev
series, Poisson series, Fourier series
.I 2230
.T
A Language for Treating Geometric Patterns in a Two-dimensional space
.W
In this paper CADEP, a problem-oriented language
for positioning geometric patterns in a two-dimensional
space, is presented.  Although the language has been
specifically designed for the automatic generation
of integrated circuit masks, it turns out to be well
suited also for such other placement problems as
architecture design, urban planning, logical and block
diagram representation.  The design criteria,
the structure, and the specific features of CADEP are illustrated.
.A
Bracchi, G.
Ferrari, D.
.K
graphic language, problem-oriented language, two-dimensional
patterns, graphic display, Fortran
extension, layout problems, integrated circuit,
architecture design, urban planning
.I 2231
.T
The Reconstruction of Binary Patterns from Their Projections
.W
Given the horizontal and vertical projections
of a finite binary pattern f, can we construct
the original pattern f?  In this paper we give a characterization
of patterns that are reconstructable
from their projection.  Three algorithms are developed
to reconstruct both unambiguous and ambiguous
patterns.  It is shown that an unambiguous pattern can
be perfectly reconstructed in time m X n and that
a pattern similar to an ambiguous pattern can also be constructed
in time m X n, where m, n are the dimensions
of the pattern frame.
.A
Chang, S.
.K
pattern reconstruction, image reconstruction, data
compression, pattern recognition, integral geometry
.I 2232
.T
Pattern Width at a Given Angle
.W
That the pattern feature "width as a function
of angle" possesses several possible interpretations
is demonstrated in this paper, which is a review of
the width concept in pattern recognition and the
geometrical concept itself.  The object of the work
is to clarify how the word description can be made
precise so that computer algorithms for feature extraction
may be obtained; the focus is on the theoretical
subject matter.  The results consist of a set-theoretic
definition of width-at-angle, a theorem relating
it to the pattern boundary radius vector, and descriptions
of alternate widths.  All widths are calculated
for an illustrative example; graphical and tabular comparisons
are given.  Substantial variation in width-at-angle
magnitude is found.  The principal conclusion is that
the set-theoretic width-at-angle is a useful pattern
feature when it can be easily computed.  Further investigation
of the information contained in only part
of a width function is recommended for cases where
computation of width-at-angle is difficult.
.A
Klinger, A.
.K
feature extraction, pattern recognition,figure
properties, picture processing, integral geometry,
width-at-angle, extent, integral projections,
linear pattern measures, width functions
.I 2233
.T
Signature Simulation and Certain Cryptographic Codes
.W
Three cyphers allegedly authored by Thomas
Jefferson Beale in 1822 have been the subject of
intensive study for over 100 years.  Generations of
cryptanalysts have expended untold man-years, thus
far without success, attempting tode code them; vast armies
of fortune hunters and treasure seekers have
devoted Herculean labors to digging up the rolling hills
of Virginia trying to locate the promised bonanza.
 The history of pertinent activities would fill volumes,
yet serious students of cryptography have always
had nagging doubts about the cyphers' authenticity.
 It has been alleged that the "known solution" to
Cypher Number Two: 115, 73, 24, 818, 37, 52, 49,...("I
have deposited in the County of Bedford about
four miles from Buford's in an excavation or vault...")
with the aid of an unsanitized version of the
Declaration of Independence was merely a superb, imaginative,
and grandiose hoax perpetrated ages ago
for whatever reasons.  Modern computer technology could
obviously perform signature analyses the process
of encoding itself so as to yield new clues and deeper
insights into their construction.  For the benefit
of the uninitiated, the encoding method used in the
second cypher employs a specified document whose
words are simply numbered consecutively, and first letters
of these words are sought out at random to
match the letters of these words are sought out at random
to match the letters of the clear text or message.
 The sequence of numbers corresponding to these matches
is then written down as the final code.  While
primitive, the process has the advantage of relative
security until the source document becomes known;
at that moment the cypher can be decoded even by second
graders.  The work now completed with the help
of our UNIVAC 1108 includes numerous analytical studies
of the Beale cyphers and various types of simulations.
 For example, we have turned the entire process of
simulated encoding by various schemes over to the
machine and analyzed the signatures of these synthetic
codes; we have also encoded various messages by
hand, using different texts and a variety of methods to
obtain their signatures. These simulations provide
convincing evidence that the signatures are both process
and data dependent; they indicate also very
strongly that Mr. Beale's cyphers are for real and that
it is merely a matter of time before someone
finds the correct source document and locates the
right vault in the common-wealth of Virginia.
.A
Hammer, C.
.K
Thomas Jefferson Beale, codes, cryptanalysis, cyphers,
decoding, Declaration of Independence, encoding,
Magna Carta, pseudotext, signature, simulation
.I 2234
.T
Roots of Matrix Pencils (Algorithm R405)
.A
Heiberger, R. M.
.K
eigenvalues, matrix roots, pencil roots
.I 2235
.T
Decision Table Translation (Algorithm R394)
.A
Marshall, D. R. T.
.K
decision table, decision table translation
.I 2236
.T
Remarks on Characteristic Values and Associated
Solutions of Mathieus Differential Equation,
Exponential Integral, and Systems of Hyperbolic
P.D.E. (Algorithms R352, R385, R392)
.A
Frisch, M. J.
.K
ANSI Fortran standard
.I 2237
.T
BANDSOLVE (Algorithm R195)
.A
Schuegraf, E.
.I 2238
.T
Least Squares Surface Fit (Algorithm R176)
.A
Schuegraf, E.
.I 2239
.T
Squank (Algorithm C379)
.A
Hallet, P.
Mund, E.
.K
numerical integration, integration rule, adaptive
integration, automatic integration, Simpson's
rule, numerical quadrature, quadrature rule, adaptive
quadrature, automatic quadrature, round-off error
control
.I 2240
.T
Pseudo-Random Numbers [G5] (Algorithm C266)
.A
Sullins, W. L.
.K
pseudo-random numbers, testing random number generators
.I 2241
.T
Product Type Three-point Gauss-Legendre-Simpson's
Integration [D1] (Algorithm A439)
.A
Boland, W. R.
.K
numerical integration, product type quadrature,
Gaussian quadrature, Simpson's rule
.I 2242
.T
Product Type Two-Point Gauss-Legendre-Simpson's
Integration [D1] (Algorithm A438)
.A
Boland, W. R.
.K
numerical integration, product type quadrature,
Gaussian quadrature, Simpson's rule
.I 2243
.T
Product Type Simpson's Integration [D1] (Algorithm A437)
.A
Boland, W. R.
.K
numerical integration, product type quadrature, Simpson's rule
.I 2244
.T
Product Type Trapezoidal Integration (Algorithm A436)
.A
Boland, W. R.
.K
numerical integration, product type quadrature, trapezoidal integration
.I 2245
.T
Trace-Driven Modeling and Analysis of
CPU Scheduling in Multiprogramming System
.W
Microscopic level job stream data obtained in
a production environment by an event-driven software
probe is used to drive a model of a multiprogramming
computer system.  The CPU scheduling algorithm of
the model is systematically varied.  This technique,
called trace-driven modeling, provides an accurate
replica of a production environment for the testing of variations
in the system.  At the same time alterations
in scheduling methods can be easily carried out in a
controlled way with cause and effects relationships
being isolated.  The scheduling methods tested included
the best possible and worst possible methods,
the traditional methods of multiprogramming theory, round-robin,
first-come-first-served, etc., and dynamic
predictors.  The relative and absolute performances of
these scheduling methods are given.  It is concluded
that a successful CPU scheduling method must be preemptive
and must prevent a given job from holding
the CPU for too long a period.
.A
Sherman, S.
Baskett III, F.
Browne, J. C.
.K
scheduling, CPU scheduling,multiprogramming,
performance measurement, trace driven models
.I 2246
.T
Levels of Language for Portable Software
.W
An increasing amount of software is being
implemented in a portable form.  A popular way of
accomplishing this is to encode the software in a specially
designed machine-independent language and
then to map this language, often using a macro processor,
into the assembly language of each desired
object machine.  The design of the machine-independent
language is the key factor in this operation.
 This paper discusses the relative merits of pitching
this language at a high level or a low level, and
presents some comparative results.
.A
Brown, P. J.
.K
portable software, level of language, machine
independent, macro processor, efficiency
.I 2247
.T
On the Criteria To Be Used in Decomposing Systems into Modules
.W
This paper discusses modularization as a mechanism
for improving the flexibility ad comprehensibility
of a system while allowing the shortening of its development
time.  The effectiveness of a "modularization"
is dependent upon the criteria used in dividing the
system into modules.  A system design problem is
presented and both a conventional and unconventional
decomposition are described.  It is shown that the
unconventional decompositions have distinct advantages
for the goals outlined.  The criteria used in
arriving at the decompositions are discussed.  The
unconventional decomposition, if implemented with
the conventional assumption that a module consists of
one or more subroutines, will be less efficient
in most cases.  An alternative approach to implementation
which does not have this effect is sketched.
.A
Parnas, D. L.
.K
software, modules, modularity, software
engineering, KWIC index, software design
.I 2248
.T
A New Method for the Solution of the
Cauchy Problem for Parabolic Equations
.W
An integral equation representation is given
for parabolic partial differential equations.
 When the equations are defined in unbounded domains, as
in the initial value (Cauchy) problem, the solution
of the integral equation by the method of successive
approximation has inherent advantages over other
methods.  Error bounds for the methods are of order h^(3/2)
and h^(7/2) (his the increment size) depending
on the finite difference approximations involved.
.A
Moore, J.
Robinson, P.
.K
parabolic equations, the Cauchy problem,
method of successive approximations
.I 2249
.T
A Comparison of Multivariate Normal Generators
.W
Three methods for generating outcomes on multivariate
normal random vectors with a specified
variance-covariance matrix are presented.  A comparison
is made to determine which method requires the
least computer execution time and memory space when utilizing
the IBM 360/67.  All methods use as a basis
a standard Gaussian random number generator.  Results
of the comparison indicate that the method based
on triangular factorization of the covariance matrix
generally requires less memory space and computer
time than the other two methods.
.A
Barr, D. R.
Sezak, N. L.
.K
random number generator, normal distribution, multivariate
normal distribution, multivariate normal
generator
.I 2250
.T
Computer Methods for Sampling from the Exponential
and Normal Distributions (Corrigendum)
.A
Ahrens, J. H.
Dieter, U.
.I 2251
.T
Weighted Increment Linear Search for Scatter Tables
.W
A new linear search for hash tables whose increment
step is a function of the key being addressed
is presented.  Comparisons with known methods are given,
in terms of efficiency and computation complexity.
 In particular, the new method applies to tables of
size n = 2^r.  It allows full table searching, and
practically eliminates primary clustering at a very low cost.
.A
Luccio, F.
.K
linear search, weighted increment search, scatter
storage, hash table, key, hash address, clustering,
search length
.I 2252
.T
A Method for Incrementally Compiling
Languages with Nested Statement Structure
.W
A method of incremental compilation is presented
which applies especially to programming languages
in which statements can be nested (such as Algol and
PL/I).  The method permits editing of the source
language using a general purpose text editor, and incremental
processing of changes without frequent
recompilation of entire routines.  The essential points
of the method are: (1) the syntax of the language
is restricted insof ar as which constructs may occur
on lines; (2) an internal data structure (called
the skeleton) is maintained to represent the statement
structure; (3) the recompilation is partially
batched in the sense that recompilation of modified lines
does not occur until the last of a set of editing
commands has been received; and (4) the parsing and
compilation are factored into two parts, that done
on individual lines and that done globally to
handle the relationships between the lines.
.A
Earley, J.
Caizergues, P.
.K
incremental compiler, interactive programming language
.I 2253
.T
Index Ranges for Matrix Calculi
.W
The paper describes a scheme for symbolic
manipulation of index expressions which arise as
a by-product of the symbolic manipulation of expressions
in the matrix calculi described by the authors
in a previous paper.  This scheme attempts program optimization
by transforming the original algorithm
rather than the machine code.  The goal is to automatically
generate code for handling the tedious address
calculations necessitated by complicated data structures.
 The paper is therefore preoccupied with "indexing
by position."  The relationship of "indexing by
name" and "indexing by position" is discussed.
.A
Bayer, R.
Witzgall, C.
.K
address calculations, algorithm transformation,
compilation, data structures, indexing by name,
indexing by position, index domain, index map, index
range, matrix expressions, normal form, programming
languages, program optimization, range operations, symbolic
manipulation, syntactic analysis, well-formed
expressions
.I 2254
.T
Dynamic Partitioning for Array Languages
.W
The classical process of partitioning an array
into subarrays is extended to a more useful
array language operation.  Various modes of partitioning
are defined for different types of arrays, so
that subarrays may vary over the original array in
a nearly arbitrary manner.  These definitions are
motivated with several realistic examples to illustrate
the value of partitioning for array languages.
 Of general interest is the data structure for partitioning.
 This consists of dynamic tree structures
which are used to derive and maintain the array control
information.  These are described in sufficient
detail to be of value in the design of other array languages.
 The description presented in this paper
is implemented in a new array language, OL/2, currently
under development at the University of Illinois.
.A
Phillips, J. R.
Adams, H. C.
.K
dynamic partitioning, array partitioning array language,
data structure, tree structure, programming
language design, array control blocks, partition control blocks
.I 2255
.T
Comments on Moorer's Music and Computer Composition
.A
Smoliar, S. W.
.K
artificial intelligence, heuristic programming,
models of cognitive processes, computer music,
computer composition, music theory
.I 2256
.T
Further Comments on Dijkstra's Concurrent Programming Control Problem
.A
Eisenberg, M. A.
McGuire, M. R.
.K
critical section, concurrent programming control, multiprocessing
.I 2257
.T
A Note on Optimal Doubly-Chained Trees
.A
Kennedy, S.
.K
file searching, doubly-chained tree, binary search tree
.I 2258
.T
Additional Results on Key-to-Address Transform
Techniques: A Fundamental Performance Study on
Large Existing Formatted Files
.A
Lum, V. Y.
Yuen, P. S. T.
.K
hashing, hashing techniques, hashing methods, hash
coding, keys, key transformation, key-to-address
transformation, direct addressing, direct access method,
randomizing, random access file organization,
file search, scatter storage, information retrieval
.I 2259
.T
Modified Incomplete Gamma Function [S14] (Algorithm A435)
.A
Fullerton, W.
.K
modified incomplete Gamma function, incomplete
Gamma function, chi-square distribution function,
Poisson distribution function
.I 2260
.T
Exact Probabilities for R x C Contingency Tables [G2] (Algorithm A434)
.A
March, D. L.
.K
probability, contingency table, test of significance
.I 2261
.T
An Approximate Method for Generating Symmetric Random Variables
.W
A method for generating values of continuous
symmetric random variables that is relatively
fast, requires essentially no computer memory, and is
easy to use is developed.  The method, which uses
a uniform zero-one random number source, is based on
the inverse function of the lambda distribution
of Turkey.  Since it approximates many of the continuous
theoretical distributions and empirical distributions
frequently used in simulations, the method should
be useful to simulation practitioners.
.A
Ramberg, J. S.
Schmeiser, B. W.
.K
simulation, Monte Carlo, probability, statistics,
approximations, random variables, random numbers,
moments, distribution
.I 2262
.T
Garbage Collection for Virtual Memory Computer Systems
.W
In list processing there is typically a growing
demand for space during program execution.
 This paper examines the practical implications of this
growth within a virtual memory computer system,
proposes two new garbage collection techniques for virtual
memory systems, and compares them with traditional
methods by discussion and by simulation.
.A
Baecker, H. D.
.K
garbage collection, virtual memory, list
processing, paging, segmentation, page tables
.I 2263
.T
The Conversion of Limited-Entry Decision Tables
to Optimal and Near-Optimal Flowcharts: Two New
Algorithms
.W
Two new algorithms for deriving optimal and
near-optimal flowcharts from limited entry decision
tables are presented.  Both take into account rule frequencies
and the time needed to test conditions.
 One of the algorithms, called the optimum-finding algorithm,
leads to a flowchart which truly minimizes
execution time for a decision table in which simple rules
are already contracted to complex rules.  The
other one, called the optimum-approaching algorithm, requires
many fewer calculations but does not necessarily
produce the optimum flowchart.  The algorithms are first
derived for treating decision tables not containing
an ELSE-rule, but the optimum-approaching algorithm
is shown to be equally valid for tables including
such a rule.  Both algorithms are compared with existing
ones and are applied to a somewhat large decision
table derived from a real case.  From this comparison two
conclusions are drawn.  (1) The optimum-approaching
algorithm will usually lead to better results than comparable
existing ones and will not require more,
but usually less, computation time.(2) In general, the
greater computation effort needed for applying
the optimum-finding algorithm will not be justified
by the small reduction in execution time obtained.
.A
Verhelst, M.
.K
decision table, flowcharting, preprocessor, optimal programs, search
.I 2264
.T
Derived Semantics for Some Programming Language Constructs
.W
The constructs of a simple programming language
are introduced and described informally in
terms of values and side-effects.  A translator is defined
which translates the language into flowcharts
for a simple machine.  The action of the machine in executing
a flowchart is defined.  A proof is constructed
that the effect of translating and executing any program
can be expressed solely in terms of the value
and side-effect of the program.  During the course of
constructing the proof, formal definitions of the
concepts of value and side-effect are derived in order
to make the proof rigorous.  Correctness of the
implementation involves checking that the definitions derived
in the step above are an acceptable formalization
of the informal description given in the first step.
.A
Henderson, P.
.K
lambda calculus, formal description, program
correctness, programming languages, semantics
.I 2265
.T
A Model for Type Checking
.W
Most current programming languages treat computation
over different classes of objects (e.g.
numbers, strings, labels and functions).  For correct
compilation and execution, the following question
then arises: is a program properly constructed so that
its operations and operands are compatible?  The
activity of answering this question is usually called
type checking.  This paper attempts to isolate
the notion of type checking and presents a partial
solution to the type checking problem based on the
notions of abstraction and application of functions.
In particular, a program is mapped into an expression
within a decidable subset of the Lambda calculus, which
characterizes the type relations within the program
and eliminates all other information.  The determination
of the type-wise correctness or incorrectness
of the program is resolved by reducing its corresponding
Lambda calculus expression to one of two normal
forms, the constant "correct" for a type-wise correct
program or the constant "error".  An application
to type checking in Algol 60 is made, and the attendant
problems faced for any notion of type checking
are discussed.
.A
Ledgard, H. F.
.K
type checking, types, Lambda calculus, models for
programming languages, syntax, semantics, compiler
writing, language implementation, formal definition
.I 2266
.T
A Highly Parallel Algorithm for Approximating
All Zeros of a Polynomial with Only Real Zeros
.W
An algorithm is described based on Newton's
method which simultaneously approximates all zeros
of a polynomial with only real zeros.  The algorithm, which
is conceptually suitable for parallel computation,
determines its own starting values so that convergence
to the zeros is guaranteed.  Multiple zeros and
their multiplicity are readily determined.  At no
point in the method is polynomial deflation used.
.A
Patrick, M. L.
.K
parallel numerical algorithms, real polynomials,
real zeros, Newton's method, starting values,
guaranteed convergence
.I 2267
.T
Algorithms To Reveal Properties of Floating-Point Arithmetic
.W
Two algorithms are presented in the form of
Fortran subroutines.  Each subroutine computes
the radix and number of digits of the floating-point
numbers and whether rounding or chopping is done
by the machine on which it is run.  The methods are
shown to work on any "reasonable" floating-point
computer.
.A
Malcolm, M. A.
.K
floating-point arithmetic, high-level
languages, philosophy of language design
.I 2268
.T
A Comparative Study of Computer Programs
for Integrating Differential Equations
.W
A study comparing the performance of several computer
programs for integrating systems of ordinary
differential equations is reported.  The integration methods represented
include multistep methods (predictor-correctors),
single-step methods (Runge-Kutta) and extrapolation methods
(both polynomial and rational).  The testing
procedure is described together with the evaluation
criteria applied.  A set of test problems on which
the programs were tested is included in an appendix.
 For the particular problems and criteria used in
the investigation it was found that a program based on
rational extrapolation showed the best performance.
.A
Fox, P.
.K
ordinary differential equations, integration,
program comparison, certification, validation
.I 2269
.T
Tableless Date Conversion (Algorithm R398)
.A
Robertson, J. D.
.K
date, calendar, Fortran statement function, arithmetic statement function
.I 2270
.T
Interpolation and Smooth Curve Fitting Based
on Local Procedures [E2] (Algorithm A433)
.A
Akima, H.
.K
interpolation, polynomial, slope of curve, smooth curve fitting
.I 2271
.T
Aesthetics and the Human Factor in Programming (Corrigendum)
.A
Ershov,A. P.
.I 2272
.T
Sorting by Natural Selection
.W
A family of sorting algorithms is proposed,
the members of which make fuller use of the memory
space and thus yield longer sorted strings.  Extensive
simulation results are presented, and various
implications and further applications are discussed.
.A
Frazer, W. D.
Wong, C. K.
.K
algorithms, sorting by replacement selection, expected string length
.I 2273
.T
Conversion of Decision Tables By Rule Mask Method Without Rule Mask
.W
Two algorithms for generating computer programs
from decision tables are described.  The algorithms
allow handling limited entry, extended entry, and mixed
entry tables.  The algorithms are based on the
rule mask method but need not have the masks at execution
time.  They perform the logical operations
immediately rather than at the end of the interpreting
process.  Execution time can be considerably reduced
by instantly marking rules which are not applicable (Algorithms
1 and 2) or conditions which are already
tested (Algorithm 2).  The new algorithms combine to a
certain degree the advantages of mask methods with
those of tree methods.
.A
Dathe, G.
.K
decision tables, rule mask, rule mask method,
rule mask technique, program generator
.I 2274
.T
Generating English Discourse from Semantic Networks
.W
A system is described for generating English
sentences from a form of semantic nets in which
the nodes are word-sense meanings and the paths are
primarily deep case relations.  The grammar used
by the system is in the form of a network that imposes
an ordering on a set of syntactic transformations
that are expressed as LISP functions.  The generation
algorithm uses the information in the semantic
network to select appropriate generation paths through
the grammar.  The system is designed for use as
a computational tool that allows a linguist to develop
and study methods for generating surface strings
from an underlying semantic structure.  Initial finding
with regard to form determiners such as voice,
form, tense, and mood, some rules for embedding sentences,
and some attention to pronominal substitution
are reported.  The system is programmed in LISP
1.5 and is available from the authors.
.A
Simmons, R.
Slocum, J.
.K
semantic nets, grammars, deep case relations,
semantic generation, discourse generation
.I 2275
.T
Integral Equations of Immunology
.W
The inversion of a particular integral equation
of the first (Fredholm) kind is the basic problem
considered.  The strategy which yielded success consisted
of three essential points: (1) fit the known
experimental data by a curve with properties which derive
from properties of the (as yet unknown) function;
(2) stabilize the computation for the unknown function
by using singular value decomposition; (3) constrain
the unknown function approximation (since it represents
a probability distribution) to be nonnegative.
 A number of test cases are presented. One set of actual
experimental data is analyzed with the procedures
presented.
.A
Hanson, R. J.
.K
integral equations of the first kind, nonnegative
constraints, singular value analysis
.I 2276
.T
Computer Methods for Sampling from
the Exponential and Normal Distributions
.W
Various methods are known for transforming uniformly
distributed random numbers into exponentially
and normally distributed quantities.  The most efficient
ones are compared, in terms of memory requirements
and speed, with some new algorithms.  A number of procedures
convert Taylor series expansions directly
into sampling steps, an approach which may be used for
sampling from any continuous distribution.  For
the exponential distribution a definite recommendation
can be made, whereas in the case of the normal
distribution there remains a choice between slower and
shorter algorithms and faster but space consuming
methods.
.A
Ahrens, J. H.
Dieter, U.
.K
random numbers, pseudorandom, normal distribution,
exponential distribution, exponential distribution,
simulation, numerical analysis
.I 2277
.T
Demand Paging Through Utilization of Working Sets on the MANIAC II
.W
A hardware implementation on the Maniac II computer
of the working set model for demand paging,
as introduced by Denning, is discussed.  Characteristics
of the Maniac II are given, along with a description
of the basic demand paging scheme and the associate memory
which has been added to the Maniac II hardware.
 Finally, a description of the hardware design for implementation
of the working set model is discussed
and a specification of the actions taken under various
conditions which may arise during the operation
of the full working set model, demand paging system is given.
.A
Morris, J. B.
.K
demand paging, dynamic storage allocation, Maniac
II, memory allocation, one-level store, paging,
paging associative memory, storage allocation,
thrashing, virtual memory, working set model
.I 2278
.T
On Foster's Information Storage and Retrieval Using AVL Trees
.A
Tan, K. C.
.K
binary trees, search trees, information storage, information retrieval
.I 2279
.T
A Controller for a Braille Terminal
.A
Rubinstein, R.
Feldman, J.
.K
blind programming aid, braille, braille character
set, braille character translation, braille computer
communication, braille computer terminal, braille terminal,
tactile computer communication, tactile terminal
.I 2280
.T
Comment on Deadlock Prevention Method
.A
Parnas, D. L.
Habermann, A. N.
.K
multiprogramming, time-sharing, scheduling, resource
allocation, deadlock, interlock, lockout,
deadly embrace, knotting
.I 2281
.T
The Eigen problem of Block Tridiagonal Matrices
.A
Khalil, H. M.
.K
linear algebra, eigenvalues and eigenvectors,
partial differential equations
.I 2282
.T
A Comparison of Floating Point Summation Methods
.A
Gregory, J.
.K
summation, floating-point addition, truncation error, error propagation
.I 2283
.T
Thinning Algorithms on Rectangular, Hexagonal, and Triangular Arrays
.W
In this report three thinning algorithms are
developed: one each for use with rectangular,
hexagonal, and triangular arrays.  The approach to the
development of each algorithm is the same.  Pictorial
results produced by each of the algorithms are presented
and the relative performances of the algorithms
are compared.  It is found that the algorithm operating
with the triangular array is the most sensitive
to image irregularities and noise, yet it will yield
a thinned image with an overall reduced number of
points.  It is concluded that the algorithm operating in
conjunction with the hexagonal array has features
which strike a balance between those of the other two arrays.
.A
Deutsch, E. S.
.K
thinning algorithms, rectangular, hexagonal,
triangular arrays, image processing, skeleton
.I 2284
.T
Solution of the Matrix Equation AX+XB=C [F4] (Algorithm A432)
.A
Bartels, R. H.
Stewart, G. W.
.K
linear algebra, matrices, linear equations
.I 2285
.T
Computer Routine for Quadratic and Linear
Programming Problems [H] (Algorithm A431)
.W
A computer program based on Lemke's complementary
pivot algorithm is presented.  This can be
used to solve linear and quadratic programming problems.
 The program has been extensively tested on
a wide range of problems and the results have been extremely satisfactory.
.A
Ravindran, A.
.K
linear program, quadratic program, complementary
problem, Lemke's algorithm, simplex method
.I 2286
.T
Automatic Error Analysis for Determining Precision
.W
The problem considered is that of evaluating a
rational expression to within any desired tolerance
on a computer which performs variable-precision floating-point
arithmetic operations.    An automatic
error analysis technique is given for determining, directly
from the results of a trial low-precision
interval arithmetic calculation, just how much precision
and data accuracy are required to achieve a
desired final accuracy.  The technique given generalize
easily to the evaluation of many nonrational
expressions.
.A
Richman, P. L.
.K
error analysis, interval arithmetic, precision control
.I 2287
.T
A New Approach to Automatic Scanning of Contour Maps
.W
The problem of automatic digitizing of contour
maps is discussed.  The structure of a general
contour map is analyzed, and its topological properties
are utilized in developing a new scanning algorithm.
 The problem of detection and recognition of contour
lines is solved by a two color labeling method.
 It is shown that for maps containing normal contour lines
only, it suffices to distinguish between so-called
"even" and "odd" lines.  The "tangency problem" involved
in practical scanning is discussed, and a solution
based on minimizing computer memory space and
simplifying control program is suggested.
.A
Mor, M.
Lamdan, T.
.K
automatic scanning, contour maps, digitizing,
contour lines, topology, detection and recognition
.I 2288
.T
File Organization: The Consecutive Retrieval Property
.W
The consecutive retrieval property is an important
relation between a query set and record
set.  Its existence enables the design of an information
retrieval system with a minimal search time
and no redundant storage.  Some important theorems on
the consecutive retrieval property are proved in
this paper.  Conditions under which the consecutive retrieval
property exists and remain invariant have
been established.  An outline for designing an information
retrieval system based on the consecutive
retrieval property is also discussed.
.A
Ghosh, S. P.
.K
file organization, consecutive storage, consecutive
retrieval, information retrieval, record organization,
query structure, record structure, storage on
tapes, storage space, minimum access time
.I 2289
.T
Cellular Arrays for the Solution of Graph Problems
.W
A cellular array is a two-dimensional, checkerboard
type interconnection of identical modules
(or cells), where each cell contains a few bits of
memory and a small amount of combinational logic,
and communicates mainly with its immediate neighbors
in the array.  The chief computational advantage
offered by cellular arrays is the improvement in speed
achieved by virtue of the possibilities for parallel
processing.  In this paper it is shown that cellular
arrays are inherently well suited for the solution
of many graph problems.  For example, the adjacency
matrix of a graph is easily mapped onto an array;
each matrix element is stored in one cell of the array,
and typical row and column operations are readily
implemented by simple cell logic.  A major challenge
in the effective use of cellular arrays for the
solution of graph problems is the determination of algorithms
that exploit the possibilities for parallelism,
especially for problems whose solutions appear to be inherently
serial.  In particular, several parallelized
algorithms are presented for the solution of certain
spanning tree, distance, and path problems, with
direct applications to wire routing, PERT chart analysis,
and the analysis of many types of networks.
 These algorithms exhibit a computation time that in
many cases grows at a rate not exceeding log2 n,
where n is the number of nodes in the graph.  Straightforward
cellular implementations of the well-known
serial algorithms for these problems require about n
steps, and noncellular implementations require from
n^2 to n^3 steps.
.A
Levitt, K. N.
Kautz, W. H.
.K
graph theory, cellular logic-in-memory arrays,
parallel processing, special purpose computers,
algorithms for distance and spanning tree problems
.I 2290
.T
Immediate Predominators in a Directed Graph [H] (Algorithm A430)
.A
Purdom Jr., P. W.
Moore, E. F.
.K
predominator, immediate predominator, graph theory,
directed graph, shortest path, articulation,
connectivity, program optimization, optimizing compiler
.I 2291
.T
Localization of the Roots of a Polynomial [C2] (Algorithm A429)
.A
Squire, W.
.K
polynomials, roots of polynomials,theory
of equations, Routh-Hurwitz criterion
.I 2292
.T
A Note on the Generation of Rosary Permutations
.A
Read, R. C.
.K
permutation, permutation generation
.I 2293
.T
Comment on Average Binary Search Length
.A
Jones, P. R.
.K
searching, binary searching, record retrieval
.I 2294
.T
A Bonus from van Wijngaarden's Device
.A
Morris Jr., J. H.
.K
non-local transfers, procedure returns
.I 2295
.T
Comment on the Composition of Semantics in Algol 68
.A
van der Poel, W. L.
.K
programming primitives, programming languages,
Algol, semantics, recursive composition, design
of programming languages, data structures
.I 2296
.T
Compiling Fixed-Point Multiplications
.A
Bernstein, H. J.
.K
compiling multiplications, fixed-point arithmetic
.I 2297
.T
A Model of Memory Contention in a Paging Machine
.W
This paper is concerned with certain aspects of contention
for main memory resources in a multiprogrammed
computer system operating under demand paging.  In
the model presented, the number of page-frames of
main memory allocated to a problem program varies in
time.  These changes in memory configuration are
represented explicitly in the model, CPU requirements and
page exception characteristics of program material
being described statistically.  Expressions for the distribution
of the number of page-frames allocated
to an executing program, the long run expected fraction
of a program's execution time in a given number
of page-frames, and the average execution interval of the
multiprogrammed load are obtained.  It is pointed
out heuristically and demonstrated numerically that
an increase is obtain able in the average execution
interval of the multiprogrammed load over that resulting
from equal fixed partitioning of main memory.
.A
Oden, P. H.
Shedler, G. S.
.K
paging machines, demand paging, operating systems
studies, queuing analysis, memory contention,
memory management
.I 2298
.T
An Environment for Research in Microprogramming and Emulation
.W
The development of the research project in
microprogramming and emulation at State University
of New York at Buffalo consisted of three phases: the
evaluation of various possible machines to support
this research; the decision to purchase one such machine,
which appears to be superior to the others
considered; and the organization and definition of goals
for each group in the project.  Each of these
phases is reported, with emphasis placed on the
early results achieved in this research.
.A
Rosin, R. F.
Frieder, G.
Eckhouse Jr., R. H.
.K
microprogramming, emulation, computer systems, language
processors, input-output systems, nano-program,
project management, hardware evaluation
.I 2299
.T
An Extensible Editor for a Small Machine with Disk Storage
.W
A design philosophy for developing a sophisticated
utility program is illustrated by the actual
design and implementation of a text editor.  A versatile
data structure is employed so that only a small
number of programmed subroutines are necessary for all
types of data manipulation.  Such a data structure
is described, and its merits are illustrated by the ease
with which powerful extensions can be implemented
in terms of a few basic editing function.
.A
Benjamin, A. J.
.K
command processing, context searching, executive
program, garbage collection, interpreter, list
processing, macro language, paging, parameter substitution,
recursion, state table, storage allocation,
string manipulation, text editing, virtual memory
.I 2300
.T
Political Redistricting by Computer
.W
The problems of political redistricting are
considered and a computer method for redistricting
is presented.  Criteria for acceptable redistricting are
discussed, including population equality, compactness,
contiguity, and preservation of natural and/or political
boundaries.  Only nonpartisan criteria are considered.
 Using 1970 Bureau of Census population data, specific
results are given for the ten Congressional Districts
in the state of Missouri and for the seven St. Louis
County Council seats.  Results from the use of the
algorithm indicate the feasibility of political
redistricting with the aid of a computer.
.A
Helbig, R. E.
Orr, P. K.
Roediger, R. R.
.K
political redistricting, reapportionment, compactness,
equal population, contiguity, transportation
algorithm, legislative districts, population units
.I 2301
.T
Generating Parsers for Affix Grammars
.W
Affix grammars are two-level grammars which
are similar to van Wijngaarden's two-level grammars
used in the definition of Algol 68.  Affix grammars are shown
by Koster to be equal in power to van Wijngaarden
grammars.  They are much more suited to parsing than
are the latter, however.  Koster, the inventor of
affix based on recursive procedures.  This paper presents
a bottom-up scheme for parsing them, based
on an extension of Floyd Production Language (FPL).  Included
is an algorithm, similar to that of DeRemer's,
for converting a large class of affix grammars into FPL.
 The paper concludes by discussing briefly the
applicabilities of the conversion algorithm and affix
grammars in general, and some possible extensions
to Koster's definition of affix grammars.
.A
Crowe, D.
.K
algorithmic language processing,bottom-up parsing,
Floyd Production Language, parsing, syntax
directed compiling, translator writing systems, two-level grammars
.I 2302
.T
Computers and Employment
.W
The relationship of computers and automation
to employment is part of the more general relation
of technological change to employment.  The most obvious
effect is that increase in productivity due
to technology can eliminate jobs.  Technology affects
the individual worker, in the nature and amount
of his work, and in his attitudes toward that work.  Technological
change affects the occupational structure
of the entire labor force.  Because of the central importance
of these effects, the impact of technology
has been the subject of extensive study by economists, sociologists,
political scientists, and psychologists.
 Even within a single discipline, studies are often contradictory,
and conclusions are colored by political
overtones.  We wish to delineate some of the issues,
and present arguments given to support different
viewpoints.
.A
Borodin, A.
Gotlieb, C. C.
.K
employment, unemployment, social implications, attitudes,
skills, obsolescence, technology, unions,
displacement
.I 2303
.T
Archaeology of Computers - Reminiscences, 1945-1947
.W
The period preceding the founding of ACM was
dominated by the first large computer ENIAC.
Its characteristics, described here, foreshadow later developments.
.A
Alt, F. L.
.K
history of computers
.I 2304
.T
A Western View of Computer History
.W
Many U.S. histories of the digital computer
field have tended to be impersonal, with heavy
emphasis on eastern universities and commercial developments.
 This article records the events of the
early years in a personal way.  The people, organizations,
technologies, and computers of the 1945-55
period in the western part of the United Statesare described as they happened.
.A
Sprague, R. E.
.K
history, computer history
.I 2305
.T
The "Plankalkul" of Konrad Zuse: A Forerunner
of Today's Programming Languages
.W
Plankalkul was an attempt by Korrad Zuse in
the 1940's to devise a notational and conceptual
system for writing what today is termed a program.  Although
this early approach to a programming language
did not lead to practical use, the plan is described
here because it contains features that are standard
in today's programming languages.  The investigation
is of historical interest; also, it may provide
insights that would lead to advancements in the state
of the art.  Using modern programming terminology,
the Plankalkul is presented to the extent it has possible
to reconstruct it from the published literature.
.A
Bauer, F. L.
Wossner, H.
.K
higher programming languages, programming,
theory of programming, history of programming
.I 2306
.T
Ancient Babylonian Algorithms
.W
The early origins of mathematics are discussed,
emphasizing those aspects which seem to be
of greatest interest from the standpoint of computer
science.  A number of old Babylonian tablets, many
of which have never before been translated into English, are quoted.
.A
Knuth, D. E.
.K
history of computation, Babylonian tablets,
sexagesimal number system, sorting
.I 2307
.T
Dynamic Document Processing
.W
The current role of computers in automatic
document processing is briefly outlined, and some
reasons are given why the early promise of library automation
and of the mechanization of documentation
processes has not been fulfilled.  A new dynamic document
environment is then outlined in which clustered
files are searched and information is retrieved following
an interactive user-controlled search process.
 Methods are described for an automatic query modification
based on user needs, and for a continuous
reorganization of the stored information as a function of
earlier file processing and of normal collection
growth.  The proposed procedures provide powerful tools
for information retrieval and for the control
of dynamic library collections in which new items
are continually added and old ones are retired.
.A
Salton, G.
.K
automatic indexing, automatic search and retrieval,
iterative searching, mechanized library processing,
collection growth, collection retirement, feedback search
.I 2308
.T
Computers and Urban Society
.W
This brief survey of the use of computers in
urban society covers the broad range of activities
found in any city.  The future scope of applications is
limited only by the imagination and inventiveness
of future system designers, programmers, analysts, and
decision makers.  The computer can be, if properly
used, with respect for human dignity and civil liberty,
a significant factor in improving the efficiency
of the urban process.  It is expected that the benefits
of such computer usage will outweigh the costs
and that we may look forward to an expansion of such usage.
.A
Sturman, G. M.
.K
urban systems, urban applications, data acquisition,
data management, engineering analysis, information
systems
.I 2309
.T
Computers in the Instructional Process:
Directions for Research and Development
.W
A survey is given of computer applications
to the instructional process which suggests how
the computer professional can contribute to effective educational systems.
.A
Zinn, K. L.
.K
education
.I 2310
.T
Language Analysis in the Humanities
.W
The use of the computer in the language-oriented
humanities for exhaustive listing of detail
(as in indices and concordances) is widespread and accepted
as desirable.  The implications of the computer
for a "science" of the humanities-a science entailing
gathering data for the construction and testing
of models-are neither widely recognized nor accepted.
 This paper argues that the computer's  major role
as to language analysis in the humanities will be the
establishing of such a science.Thus, for those
areas of the humanities for which rigor and precision
are necessary (e.g. analyzing literature or teaching
a student to write a composition) the computer
can be a critically important facilitator.
.A
Sedelow, S. Y.
.K
language analysis, humanities, science of the humanities,
pattern recognition, pattern generation,
interdisciplinary cooperation
.I 2311
.T
A Generational Perspective of Information System Development
.W
System development is categorized from a generational
point of view that parallels the commonly
described computing system generations.  For each generation,
the scope of development projects and the
technological world view of the system developer are examined.
.A
Benjamin, R. I.
.K
computing milieu, management data processing, hardware
systems, software systems, systems development
process, functional systems, management systems
.I 2312
.T
On the Present and Future of Scientific Computation
.W
A pessimistic forecast is given of what can be
expected to happen in the application of computers
to the physical sciences.
.A
Rice, J. R.
.K
scientific computation
.I 2313
.T
The Evolution of Storage Structures
.W
Data base management systems have grown rapidly
in their power and complexity over the 15-year
history of data processing on commercially available
computers.  The original concepts have split, and
new terms have been adopted to name and refer to these
concepts.  The Data Structure Diagram graphic
technique is used to illustrate the splitting of the
concepts and the structural relations which exist
between these concepts at each point in the evolution.
.A
Bachman, C. W.
.K
block, cylinder, device, field, extent file, page,
record, physical record, logical record, track,
volume, entity, set, entity class, set class, data structure
diagram, storage structure, physical storage
structure, logical storage structure, storage allocation
structure, Integrated Data Store, index sequential,
hash, randomize, item
.I 2314
.T
Requirements for Advanced Programming Systems for List Processing
.W
List processing systems should be designed to
facilitate production of large programs to manipulate
large complex symbolic data stores.  This paper presents
an overview of a number of system features which
the author feels are important to improve the productivity
of programmers working in such domains.  A
system view it taken, rather than focusing just on language
features, since algorithms must be not only
coded in a language form, but debugged, modified, made
efficient, and run on data.  Because of this general
framework,the requirements specified are applicable
to the design of advanced programming systems for
a wide range of applications.  Three aspects of programming
systems are highlighted: good interactive
facilities, programmable control structures, and sophisticated
data communication mechanisms.  Interactive
features are described to facilitate program composition,
entry, testing, debugging, editing, optimization,
and packaging.  Implementation of a generalized environment
structure model specified would allow programming
of various control regimes including multiprocesses,
coroutines and backtracking.  Alternative methods
of procedure invocation required include invocation
by pattern and by monitoring condition.  The  need
for extended data forms, storage management, and extensibility
are stressed, as is the duality of data
retrieval and function evaluation.  Syntax directed
input and output of data would facilitate use of
complex data stores.
.A
Bobrow, D. G.
.K
list processing, programming languages, design of
programming languages, interactive systems, control
structures, data structures, programming primitives,
semantics, advanced programming systems
.I 2315
.T
The Production of Better Mathematical Software
.W
Some observations are made on steps to be
taken toward the creation of better mathematical
software.  These steps suggest the need for a coordinated
effort and the creation of a center to focus
activities in this area.
.A
Fosdick, L. D.
.K
mathematical software, programming
.I 2316
.T
Programming Languages: History and Future
.W
This paper discusses both the history and future
of programming languages (= higher level languages).
 Some of the difficulties in writing such a history
are indicated.  A key part of the paper is a tree
showing the chronological development of languages and their
interrelationships.  Reasons for the proliferation
of languages are given.  The major languages are listed
with the reasons for their importance.  A section
on chronology indicates the happenings of the significant
previous time periods and the major topics
of 1972.  Key concepts other than specific languages are discussed.
.A
Sammet, J. E.
.K
programming languages, higher level languages,
languages, history, future directions, language
interrelationships, programming language tree, programming
language history, programming language future
.I 2317
.T
Programming Systems and Languages 1965-1975
.W
In spite of impressive gains by PL/I, Fortran
and Cobol remain the languages in which most
of the world's production programs are written and will
remain so into the foreseeable future.  There
is a great deal of theoretical interest in Algol 68
and in extensible languages, but so far at least
they have had little practical impact.  Problem-oriented
languages may very well become the most important
language development area in the next five to ten years.
 In the operating system area all major computer
manufacturers set out to produce very ambitious multiprogramming
systems, and they all ran into similar
problems.  A number of university projects,though not
directly comparable to those of the manufacturers,
have contributed greatly to a better understanding
of operating system principles.  Important trends
include the increased interest in the development of
system measurement and evaluation techniques,and
increased use of microprogramming for some programming system functions.
.A
Rosen, S.
.K
languages, operating systems, programming
systems, multiprogramming, history
.I 2318
.T
The Role of Computer System Models in Performance Evaluation
.W
Models constitute a useful means of investigating
computer system performance.  This paper
examines the interrelationships between models and other
methods for evaluating the performance of computer
systems and establishes circumstances under
which the use of a model is appropriate.
.A
Kimbleton, S. R.
.K
modeling, evaluation, performance, analytic-models,
simulation-models, system-models
.I 2319
.T
Operating System Performance
.W
An overview of the current and future positions
with respect to operating system performance
is given.  While a great deal of information and a large
number of models for subsystems have been developed,
gaps still exist in out knowledge.  Because of the
severe interactions between the various subsystems
of an operating system, an overall model of the total
system must be developed to be able to analyze
and design the performance aspects of an operating system
although such total system designs are exceptional
today, it is projected that they will become increasingly
more common and necessary in the near future.
 Such a design philosophy will clearly have a severe impact
on the way we go about modularizing operating
and computer systems.
.A
Lynch, W. C.
.K
computer system, operating system, performance
evaluation, performance measurement, measurement,
techniques, modularity, layering, structured programming,
paging, virtual memory, input/output, disk
storage facility, drum storage facility, sector queueing
.I 2320
.T
Structured Multiprogramming
.W
This paper presents a proposal for structured
representation of multiprogramming in a high
level language.  The notation used explicitly associates
a data structure shared by concurrent processes
with operations defined on it.  This clarifies the meaning
of programs and permits a large class of time-dependent
errors to be caught at compile time.  A combination of
critical regions and event variables enables the
programmer to control scheduling of resources among
competing processes to any degree desired.  These
concepts are sufficiently safe to use not only within
operating systems but also within user programs.
.A
Hansen, P. B.
.K
structured multiprogramming, programming languages,
operating systems, concurrent processes, shared
data, mutual exclusion, critical regions, process
communication, synchronizing events.
.I 2321
.T
On the Interface Between Computers and Data Communications Systems
.W
Future systems that combine computers, digital
terminals, and communications equipment present
design optimization problems that require reconsideration
of the traditional functional responsibilities
of the respective subsystems.  Several "standard" interfaces,
by means of which computers and digital
terminals connect to the communications systems will
be required.  When specifying these interfaces,
consideration must be given to problems of coordination,
synchronization, error control, signaling, stream
multiplexing, and switch control, in addition to minimizing
the technological interdependence of specific
subsystem designs.  A focus on some of the problems is
obtained in a discussion of a detailed specification
for a particular computer-communications system interface.
.A
Fraser, A. G.
.K
communications, standard interface communications
protocol, virtual channel, multiplexed input/output,
coordination of input/output
.I 2322
.T
A View of computer Architecture
.W
An attempt is made to predict the developments
of the next 25 years in the field of computer
architecture.  Standardized, inexpensive microcomputers
on a single chip are predicted.  These will be
used extensively to provide logical functions for noncomputational
devices and incidentally for the design
of superscale computers.
.A
Foster, C. C.
.K
computer architecture, projection, microcomputers,
computer design, computer organization
.I 2323
.T
Toward a General Theory of Special Functions
.W
A list of a number of natural developments
for the field of algebraic manipulation is given.
 Then the prospects for a general theory of functions
defined by ordinary differential equations are
discussed.  The claim is made that recent developments
in mathematics indicate that it should be possible
to algorithmically generate many properties of solutions
to differential equations.  Such a theory is
preferable to a less general effort to make algebraic
manipulation systems knowledgeable about the usual
special functions (e.g. exponential, hypergeometric).
.A
Moses, J.
.K
algebraic manipulation, special functions, algebraic
simplification, symbolic integration, algebraic
geometry, differential algebra
.I 2324
.T
Management Science: A View from Nonlinear Programming
.W
A brief history of integer and continuous
nonlinear programming is presented as well as the
current obstacles to practical use of these mathematical
programming techniques.  It is forecast that
the useful contributions to nonlinear programming actually
made in the next few years are more likely
to be consolidations than theoretical breakthroughs.  These
contributions are likely to be the documentation
of standard test problems, construction of user oriented
software, and comparisons of currently known
algorithms to demonstrate which techniques are best for specific problems.
.A
Shanno, D. F.
Weil, R. L.
.K
integer programming, linear programming, mathematical
programming, nonlinear programming, quadratic
programming, management science, operations research, algorithms
.I 2325
.T
Numerical Mathematics and Computer Science
.W
Numerical mathematics is viewed as the analysis
of continuous algorithms.  Four of the components
of numerical mathematics are discussed.  These are: foundations
(finite precision number systems, computational
complexity), synthesis and analysis of algorithms,
analysis of error, programs and program libraries.
.A
Traub, J. F.
.K
numerical mathematics, computer science, mathematics
of computation, algorithms, continuous algorithms
.I 2326
.T
Fix point Approach to the Theory of Computation
.W
Following the fix point theory of Scott, the
semantics of computer programs are defined in terms
of the least fix points of recursive programs.  This
allows not only the justification of all existing
verification techniques, but also their extension to the
handling, in a uniform manner of various properties
of computer programs, including correctness, termination, and equivalence.
.A
Manna, Z.
Vuillemin, J.
.K
verification techniques, semantics of programming
languages, least fix points, recursive programs,
computational induction
.I 2327
.T
Toward an Automata Theory of Brains
.W
A source of ideas for automata theory-the study
of the brain-has been pushed aside in mathematical
development of the theory.  This paper suggests the ways
in which automata theory might evolve over the
next 25 years if it is to contribute to an understanding
of how the brain processes information.
.A
Arbib, M. A.
.K
automata theory, brain theory, network complexity,
resolution of redundancy of potential command,
frog visual system, reticular formation mode selection
.I 2328
.T
Individualizing Instruction in a Generative CAI Tutor
.A
Koffman, E. B.
.K
computer-assisted instruction, generative CAL, adaptive instruction
.I 2329
.T
Computer Science-A Vicious Circle
.A
Kandel, A.
.K
education, computer engineering, computer
science curriculum, systems design
.I 2330
.T
Calculation of Fourier Integrals (Algorithm R418)
.A
Einarsson, B.
.K
quadrature, Filon quadrature, integration, Filon integration,
Fourier coefficients, Fourier integrals,
Fourier series, spline,spline approximation, spline
quadrature, extrapolation, Richardson extrapolation
.I 2331
.T
An Integer Programming Problem (Algorithm R397)
.A
Johnson, S. C.
Kernighan, B. W.
.K
integer programming, change-making problem
.I 2332
.T
Special Series Summation with Arbitrary Precision (Algorithm R393)
.A
Sale, A. H. J.
.K
function evaluation, series summation, approximation
.I 2333
.T
Random Vectors Uniform is Solid Angle (Algorithm R381)
.A
Schrack, G. F.
.K
random vector generator, points uniform on sphere,
spherically symmetric probability distribution
.I 2334
.T
General Random Number Generator (Algorithm R370)
.A
Proll, L. G.
.K
random number generator, probability density function,
transformation, cumulative distribution
function
.I 2335
.T
Eigenvalues and Eigenvectors of a Real General matrix (Algorithm R343)
.A
Niessner, H.
.K
eigenvalues, eigenvectors, QR-algorithm,
nonsymmetric matrices, general matrices
.I 2336
.T
Complex Error Function (Algorithm C363)
.A
Kolbig, K. S.
.K
error function for complex argument, Voigt function,
special functions, function evaluation
.I 2337
.T
A Sorting Problem and Its Complexity
.W
A technique for proving min-max norms of sorting
algorithms is given.  One new algorithm for
finding the minimum and maximum elements of a set with
fewest comparisons is proved optimal with this
technique.
.A
Pohl, I.
.K
sorting, computational complexity, computational combinatorics
.I 2338
.T
A Starting Method for Solving Nonlinear Volterra
Integral Equations of the Second Kind
.W
A fourth-order starting method is given for
Volterra integral equations of the second kind
and numerical examples are presented.
.A
Iguchi, K.
.K
algorithm, Volterra integral equations, starting method
.I 2339
.T
Computer-Assigned Codes from Verbal Responses
.W
It is often desirable to convert verbal responses
to multidigit codes. This conversion is generally
accomplished by clerk-coders.  A study was conducted to test
the feasibility of translating verbal descriptions
to numerical codes in a computer program.  Primary emphasis
was placed on computerized construction of
a reference file of verbal descriptions for use by the
program.  The results of the study clearly show
that such procedures are feasible.
.A
O'Reagan, R. T.
.K
verbal responses, computer coding, reference list,
historical response patterns, word strings,
concept translation, word coding
.I 2340
.T
A Boolean Matrix Method for the Computation
of Linear Precedence Functions
.W
A modified version of Bell's Boolean matrix
method for the computation of linear precedence
functions associated with a conflict-free matrix of
precedence relations is given.  This algorithm not
only detects when the precedence functions do not  exist,
but also provides an indication of why they
do not exist, so that corrective action can be taken
if possible.  Necessary and sufficient conditions
for the existence of precedence functions are given.
 The use of Boolean matrices to prove the existence
of precedence functions associated with classes of conflict-free
grammars is illustrated through an example.
.A
Martin, D. F.
.K
precedence grammars, context-free parsing
.I 2341
.T
Blocks-A New Data type for SNOBOL4
.W
A new data type, called a block, has been implemented
for SNOBOL4.  A block is a three-dimensional
aggregate of characters in the form of a right parallelepiped,
best thought of as a three-dimensional
extension to a string.  (The third dimension is used for
overstriking.)  Blocks may be printed, concatenated
in any of three dimensions, and merged on the basis
of program-defined connection points.  Some blocks
adapt in size and shape to their environment.  Blocks
and their operations are mainly used for composing
printable output.  A variety of graphical problems (including
flowcharting, bargraphs, logic diagrams,
mathematical-equation formation, and text justification
and preparation) have been programmed on a printer
in what appears to be an easy and natural way.  In addition
to these somewhat specialized applications,
blocks appear to be a good general purpose device-independent
output formation mechanism especially suitable
for nonnumerical work.  The concept of a block is largely
language independent.That is, blocks require
little in the way of specialized syntax and could readily
be absorbed into the external structure of
most programming languages.
.A
Gimpel, J. F.
.K
character manipulation, output formatting, string
processing, graphics, nonnumerical programming,
SNOBOL4, data types, two-dimensional mathematics, test processing, flowcharting
.I 2342
.T
Interference Between Communicating Parallel Processes
.W
Various kinds of interference between communicating
parallel processes have been examined by
Dijkstra, Knuth, and others.  Solutions have been given
for the mutual exclusion problem and associated
subproblems, in the form of parallel programs, and informal
proofs of correctness have been given for
these solutions.  In this paper a system of parallel
processes is regarded as a machine which proceeds
from one state S (i.e. a collection of pertinent data
values and process configurations) to a next state
S' in accordance with a transition rule S --> S'.  A
set of such rules yields sequences of states, which
dictate the system's behavior.  The mutual exclusion problem
and the associated subproblems are formulated
as questions of inclusion between sets of states, or
of the existence of certain sequences.  A mechanical
proof procedure is shown, which will either verify (prove
the correctness of ) or discredit (prove the
incorrectness of) an attempted solution, with respect
to any of the interference properties.  It is shown
how to calculate transition rules from the "partial
rules" by which the individual processes operate.
 The formation of partial rules and the calculation of
transition rules are both applicable to hardware
processes as well as to software processes, and
symmetry between processes is not required.
.A
Gilbert, P.
Chandler, W. J.
.K
concurrent programming control, cooperating processes,
formal programs, interference, mutual exclusion,
operating systems, parallel processes
.I 2343
.T
A Proposal To Establish a Pseudo Virtual Memory via Writable Overlays
.W
Many computer systems solve executable storage
size problems for large programs by using overlays.
 However, it appears that no one overlay scheme contains
a well-balanced combination of the most useful
capabilities which are found in various existing techniques.
 A proposal is presented which utilizes
several of the best capabilities from existing schemes
and is complemented by several additional features,
e.g. writable overlays.  The writable overlay capability
provides a virtual memory effect, although the
programmer may still be required to design the overlay
configuration.  Since overlay structuring is a
complex task, several tools (including a graphic display)
are included in the proposal in order to aid
the programmer in the design.  The content of overlays
is briefly discussed, and it is noted that many
of the details of the final overlay configuration may be decided after the fact.
.A
Spacek, T. R.
.K
overlay, overlay structure, segment, segmentation,
folding, paging, linkage editor, collector,
loader, virtual memory
.I 2344
.T
On the Optimization of Performance of Time-Sharing Systems by Simulation
.W
A simulation model of a time-sharing system
with a finite noncontiguous store and an infinite
auxiliary store is used to study the variation of system
parameters such as store size, number of jobs
allowed to execute simultaneously, job-scheduling algorithm,
etc.  The effects of these variations on
a measure of system performance is used to ascertain which
of the parameters controllable by the job-scheduling
algorithm, including the scheduling itself, require optimization,
and which of the parameters not normally
controllable by the scheduling algorithm have a marked
effect on system performance.  System performance
is based upon the mean cost of delay to all jobs processed.
 It is shown that significant improvements
in the measure of system performance can be obtained by
using variable time-slice techniques and by selecting
the optimum round-robin cycle time.  It appears that these
features would benefit from optimization whereas
other parameters controllable by the scheduling algorithm
affect system performance in a predictable
manner and would not benefit from optimization.  Features
not normally under the control of the scheduling
algorithm can also have a marked effect on the measure
of performance; in particular, supervisor overheads,
the size of the store, and the speed of the CPU.  A comparison
is made between the results of the simulation
model and two analytical equations for quantum-oriented
nonpreemptive time-sharing systems.  The comparison
is found to be very favorable.
.A
Blatny, J.
Clark, S. R.
Rourke, T. A.
.K
time-sharing, simulation studies, optimization,
measure of performance, scheduling algorithms
.I 2345
.T
Curriculum Recommendations for Graduate
Professional Programs in Information Systems
.W
The need for education related to information
systems in organizations is discussed, and a
curriculum is proposed for graduate professional programs
in universities, at the Master's level.  Material
necessary for such programs is identified, and courses
incorporating it are specified.  Detailed course
descriptions are presented, program organization discussed,
and implementation questions considered.
.A
Ashenhurst, R. L.
.K
education, management systems, systems analysis,
management information systems, information systems
development, information analysis, system design
.I 2346
.T
Hu-Tucker Minimum Redundancy Alphabetic
Coding Method [Z] (Algorithm A428)
.A
Yohe, J. M.
.K
information theory, coding theory, Hu-Tucker
method, minimum redundancy coding
.I 2347
.T
Fourier Cosine Integral [D1] (Algorithm A427)
.A
Linz, P.
.K
numerical integration, quadrature, adaptive quadrature,
Filon quadrature, Fourier coefficients,
Fourier integrals
.I 2348
.T
Merge Sort Algorithm [M1] (Algorithm A426)
.A
Bron, C.
.K
sort, merge
.I 2349
.T
Generation of Random Correlated Normal Variables [G5] (Algorithm A425)
.A
Hurst, R. L.
Knop, R. E.
.K
random number, normal density, normal distribution,
Gaussian density, Gaussian distribution, simulation,
Monte Carlo
.I 2350
.T
Clenshaw-Curtis Quadrature [D1] (Algorithm A424)
.A
Gentleman, W.M.
.K
quadrature, Chebyshev series, cosine transform, fast Fourier transform
.I 2351
.T
The Optimality of Winograd's Formula
.A
Harter, R.
.K
inner product, Winograd's formula
.I 2352
.T
Minimax Nonlinear Approximation by Approximation on Subsets
.A
Dunham, C. B.
.K
minimax approximation, nonlinear approximation, subset
.I 2353
.T
Fast Finite-Difference Solution of Biharmonic Problems
.W
Setting the Reynolds number equal to zero, in
a method for solving the Navier-Strokes equations
numerically, results in a fast numerical method for
biharmonic problems.  The equation is treated as
a system of two second order equations and a simple
smoothing process is essential for convergence.
An application is made to a crack-type problem.
.A
Greenspan, D.
Schultz, D.
.K
numerical analysis, partial differential equations,
biharmonic equation, boundary value problem
.I 2354
.T
Implementing Clenshaw-Curtis Quadrature,
II Computing the Cosine Transformation
.W
In a companion paper to this, "I Methodology
and Experiences," the automatic Clenshaw-Curtis
quadrature scheme was described and how each quadrature
formula used in the scheme requires a cosine
transformation of the integrand values was shown.
The high cost of these cosine transformations has
been a serious drawback in using Clenshaw-Curtis quadrature.
 Two other problems related to the cosine
transformation have also been trouble some.  First, the
conventional computation of the cosine transformation
by recurrence relation is numerically unstable, particularly
at the low frequencies which have the largest
effect upon the integral.  Second, in case the automatic
scheme should require refinement of the sampling,
storage is required to save the integrand values after
the cosine transformation is computed.  This second
part of the paper shows how the cosine transformation can
be computed by a modification of the fast Fourier
transform and all three problems overcome.  The modification
is also applicable in other circumstances
requiring cosine or sine transformations, such as polynomial
interpolation through the Chebyshev points.
.A
Gentleman, W. M.
.K
fast Fourier transformation, cosine transformation,
Clenshaw-Curtis quadrature, Chebyshev series
.I 2355
.T
Implementing Clenshaw-Curtis quadrature, I Methodology and Experience
.W
Clenshaw-Curtis quadrature is a particularly
important automatic quadrature scheme for a variety
of reasons, especially the high accuracy obtained from
relatively few integrand values.  However, it
has received little use because it requires the computation
of a cosine transformation and the arithmetic
cost of this has been prohibitive.  This paper is in
two parts; a companion paper, "II Computing the
Cosine Transformation," shows that this objection can
be overcome by computing the cosine transformation
by a modification of the fast Fourier transform algorithm.
 This first part discusses the strategy and
various error estimates, and summarizes experience
with a particular implementation of the scheme.
.A
Gentleman, W. M.
.K
Clenshaw Curtis, numerical integration, automatic
quadrature, error estimates, Chebyshev series
.I 2356
.T
A Technique for Software Module Specification with Examples
.W
This paper presents an approach to writing
specifications for parts of software systems.  The
main goal is to provide specifications sufficiently
precise and complete that other pieces of software
can be written to interact with the piece specified without
additional information.  The secondary goal
is to include in the specification no more information
than necessary to meet the first goal.  The technique
is illustrated by means of a variety of examples from a tutorial system.
.A
Parnas, D. L.
.K
software, specification, modules, software engineering, software design
.I 2357
.T
MUX, a Simple Approach to On-Line Computing
.W
An on-line system operating as part of a normal
batch system for the CDC 6600 computer is described.
 The system, which required one man-year for initial
software implementation, although basically simple,
provides the necessary elements to input and modify files,
submit them for batch execution, and provide
results at the user's terminal.  A multiplexer designed
and developed as part of the project cost one
man-year for design and checkout, and $16,000 for parts
and fabrication.  All aspects of the system are
described, including design criteria, implementation,
cost, overhead, and user reactions.
.A
Christman, R. D.
.K
time-sharing, remote computing, on-line access,
on-line computing, remote file manager, real time,
multiplexer, implementation effort, operating overhead,
user reactions, remote terminals, operating system
.I 2358
.T
The Multics Virtual Memory: Concepts and Design
.W
As experience with use of on-line operating
systems has grown, the need to share information
among system users has become increasingly apparent.
 Many contemporary systems permit some degree of
sharing.  Usually, sharing is accomplished by allowing
several users to share data via input and output
of information stored in files kept in secondary storage.
 Through the use of segmentation, however,
Multics provides direct hardware addressing by user and
system programs of all information, independent
of its physical storage location.  Information is stored
in segments each of which is potentially sharable
and carries its own independent attributes of size and access
privilege.  Here, the design and implementation
considerations of segmentation and sharing in Multics
are first discussed under the assumption that all
information resides in large, segmented main memory.
Since the size of main memory on contemporary systems
is rather limited, it is then shown how the Multics
software achieves the effect of a large segmented
main memory through the use of the Honeywell
645 segmentation and paging hardware.
.A
Bensoussan, A.
Clingen, C. T.
Daley, R. C.
.K
operating system, Multics, virtual memory, segmentation,
information sharing, paging, memory management,
memory hierarchy
.I 2359
.T
An Improved Index Sequential Access Method Using Hashed Overflow
.W
The Index Sequential Access Method (ISAM) is
one of the most important file management systems
used with moveable head disk devices.  This study investigates
the use of an unconventional method of
treating overflow records.  The method is to use hashing
techniques to allocate space for such records.
 If certain conditions are satisfied, this is superior
to the conventional ISAM method of chaining the
overflow records via linked list techniques.  These conditions are:
long overflow chains with significant
overflow; lack of tight disk space constraints; record
keys which are small compared to the total record
size; and significant use of the file in the index as opposed
to the sequential mode.  Using hashed overflow,
the time to locate a record is dependent not on the total
volume of overflow records as in conventional
ISAM, but on the percentage use of space dedicated to overflow records.
.A
Mullin, J. K.
.K
ISAM, index sequential, hashing, scatter
storage, disk, cylinder, overflow
.I 2360
.T
A Comment on the Double-Chained Tree
.A
Hu, T. C.
.K
file searching, double-chained tree, binary search tree
.I 2361
.T
A Note on Cheney's Nonrecursive List-Compacting Algorithm
.A
Walden, D. C.
.K
list compacting, garbage collection
.I 2362
.T
Linear Equation Solver [F4] (Algorithm A423)
.A
Moler, C. B.
.K
matrix algorithms, linear equations, Fortran,
paged memory, virtual memory, array processing
.I 2363
.T
Minimal Spanning Tree [H] (Algorithm A422)
.A
Whitney, V. K. M.
.K
spanning tree, minimal spanning tree, maximal spanning tree
.I 2364
.T
Complex Gamma Function with Error Control [S14] (Algorithm A421)
.A
Kuki, H.
.K
complex gamma function, gamma function, complex
log gamma function, loggamma function, round-off
error control, inherent error control, run-time error
estimates, error estimates, special functions
.I 2365
.T
Matrix Computations with Fortran and Paging
.W
The efficiency of conventional Fortran programs
for matrix computations can often be improved
by reversing the order of nested loops.  Such modifications
produce modest savings in many common situations
and very significant savings for large problems run
under an operating system which uses paging.
.A
Moler, C. B.
.K
matrix algorithms, linear equations, Fortran,
paged memory, virtual memory, array processing
.I 2366
.T
Complex Gamma Function with Error Control
.W
An algorithm to compute the gamma function and
log gamma function of a complex variable is presented.
 The standard algorithm is modified in several respects
to insure the continuity of the function value
and to reduce accumulation of round-off errors.  In
addition to computation of function values, this
algorithm includes an object-time estimation of round-off
errors.  Experimental data with regard to the
effectiveness of this error control are presented.
A Fortran program for the algorithm appears in the
algorithms section of this issue.
.A
Kuki, H.
.K
complex gamma function, gamma function, complex
log gamma function, loggamma function, round-off
error control, inherent error control, run-time error estimates, error estimates
.I 2367
.T
Computers and Society: A Proposed Course for Computer Scientists
.W
The purpose of this paper is to describe a course
concerned with both the effects of computers
on society and the responsibilities of computer scientists
to society.  The impact of computers is divided
into five components: political, economic, cultural, social,
and moral; the main part of the paper defines
each component and presents examples of the relevant
issues.  In the remaining portions the possible
formats for such a course are discussed, a topic by topic
outline is given, and a selected set of references
is listed.  It is hoped that the proposal will make
it easier to initiate courses on this subject.
.A
Horowitz, E.
Morgan, H. L.
Shaw, A. C.
.K
computers and society, social implications, course proposal
.I 2368
.T
An Implemented Graph Algorithm for Winning Shannon Switching games
.W
In this tutorial paper a computer program
which wins Shannon Switching Games is described.
 Since these games are played on graphs, the program
is a good example of the implementation of graph
algorithms.  The two players in a Shannon Switching Game,
CONNECT and CUT, have nonsimilar goals.  Either
CONNECT, CUT, or the player moving first is guaranteed
the existence of a winning strategy.  The simple
strategy explained in this paper is valid in all three
cases.  In fact, the major routines never need
to know whether the computer is CONNECT or CUT.
.A
Chase, S. M.
.K
graph algorithms, graph processing, Shannon Switching
Games, game playing, graph theory, positional
games, demonstration programs, game theory, spinning trees
.I 2369
.T
Hidden Lines Elimination for a Rotating Object
.W
A method is presented of determining which
parts of three-dimensional objects are visible and
which are invisible when the objects are rotated about
some axis.  This paper describes a polygon comparison
scheme in which the relationships of two polygons can
be classified into tree types, and also discusses
how the relationship is changed for each pair of polygons
under rotation about some axis.  A rotation
table is defined for each pair of polygons, which remains
fixed as long as rotation is about one axis
and provides a means of rapidly determining the visible
and hidden line relationship between two polygons.
 Additional work must be done to extend this approach
to simultaneous rotation about several axes.
.A
Matsushita, Y.
.K
hidden line problem, display programming, computer
graphics, displays, graphics, computer drawn
picture
.I 2370
.T
An Experimental Laboratory for Pattern Recognition and Signal Processing
.W
An interactive computer-controlled scanning
and display system has been in operation at the
IBM Thomas J. Watson Research Center for three years.
 The system includes two flying-spot scanners and
a TV camera specially interfaced to a process control
digital computer, dot-mode and vector displays,
analog input and output facilities, and a variety of
other experimental equipment.  The system design
and programming support are described and typical applications
in scanner control, optical character
recognition,and image processing are presented.
.A
Herbst, N. M.
Will, P. M.
.K
scanners, pseudorandom displays, interactive
terminal, image processing, pattern recognition
.I 2371
.T
A System for Interprocess Communication
in a Resource Sharing Computer Network
.W
A system of communication between processes in a
time-sharing system is described and the communication
system is extended so that it may be used between processes
distributed throughout a computer network.
 The hypothetical application of the system to an existing network is discussed.
.A
Walden, D. C.
.K
interprocess communication, time-sharing,
computer networks, resource sharing
.I 2372
.T
On the Implementation of Security Measures in Information Systems
.W
The security of an information system may be
represented by a model matrix whose elements are
decision rules and whose row and column indices are
users and data items respectively.  A set of four
functions is used to access this matrix at translation
and execution time.  Distinguishing between data
dependent and data independent decision rules enables
one to perform much of the checking of security
only once at translation time rather than repeatedly
at execution time.  The model is used to explain
security features of several existing systems, and serves
as a framework for a proposal for general security
system implementation within today's languages and operating systems.
.A
Conway, R. W.
Maxwell, W. L.
Morgan, H. L.
.K
security, privacy, access control confidentiality,
operating systems, access management, data banks,
management information systems
.I 2373
.T
Properties of the Working-Set Model
.W
A program's working set W(t,T) at time t is
the set of distinct pages among the T most recently
referenced pages.  Relations between the average working-set size,
the missing-page rate, and the interreference-interval
distribution may be derived both from time-average definitions
and from ensemble-average (statistical)
definitions. An efficient algorithm for estimating these
quantities is given.  The relation to LRU (least
recently used) paging is characterized.  The independent-reference
model, in which page references are
statistically independent, is used to assess the effects
to interpage dependencies on working-set size
observations. Under general assumptions, working-set
size is shown to be normally distributed.
.A
Denning, P. J.
Schwartz, S. C.
.K
working-set model, paging, paging algorithms,
program behavior, program modeling
.I 2374
.T
A Study of Storage Partitioning Using a Mathematical Model of Locality
.W
Both fixed and dynamic storage partitioning
procedures are examined for use in multiprogramming
systems.  The storage requirement of programs is modeled
as a stationary Gaussian process.  Experiments
justifying this model are described.  By means of this
model dynamic storage partitioning is shown to
provide substantial increases in storage utilization
and operating efficiency over fixed partitioning.
.A
Coffman Jr., E. G.
Ryan Jr., T. A.
.K
storage partitioning, memory management, dynamic
storage allocation, space sharing, multiprogrammed
storage, working-sets, program behavior models, mathematical modeling
.I 2375
.T
A Comparative Analysis of Disk Scheduling Policies
.W
Five well-known scheduling policies for movable
head disks are compared using the performance
criteria of expected seek time (system oriented)and expected
waiting time (individual I/O request oriented).
 Both analytical and simulation results are obtained.
 The variance of waiting time is introduced as
another meaningful measure of performance, showing possible
discrimination against individual requests.
 Then the choice of a utility function to measure total
performance including system oriented and individual
request oriented measures is described.  Such a function
allows one to differentiate among the scheduling
policies over a wide range of input loading conditions.
 The selection and implementation of a maximum
performance two-policy algorithm are discussed.
.A
Teorey, T. J.
Pinkerton, T. B.
.K
access time, analytical models, auxiliary storage,
direct access storage, disk analysis, disk scheduling,
performance criteria, peripheral memory devices, real-time
systems, response time, rotational delay,
scheduling policies, seek time, simulation, storage
units, time-sharing systems, waiting time
.I 2376
.T
Synchronization of Communicating Processes
.W
Formalization of a well-defined synchronization
mechanism can be used to prove that concurrently
running processes of a system communicate correctly.
 This is demonstrated for a system consisting of
many sending processes which deposit messages in a buffer
and many receiving processes which remove messages
from that buffer.  The formal description of the synchronization
mechanism makes it very easy to prove
that the buffer will neither overflow nor underflow,
that senders and receivers will never operate on
the same message frame in the buffer nor will they run into a deadlock.
.A
Habermann, A. N.
.K
parallel programming, multiprogramming, program correctness,
process communication, process scheduling
.I 2377
.T
A Hardware Architecture for Implementing Protection Rings
.W
Protection of computations and information
is an important aspect of a computer utility.  In
a system which uses segmentation as a memory addressing
scheme, protection can be achieved in part by
associating concentric rings of decreasing access privilege
with a computation.  This paper describes
hardware processor mechanisms for implementing these rings
of protection.  The mechanisms for implementing
these rings of protection. The mechanisms allow cross-ring
calls and subsequent returns to occur without
trapping to the supervisor.  Automatic hardware validation
of references across ring boundaries is also
performed.  Thus, a call by a user procedure to a protected
subsystem (including the supervisor) is identical
to a call to a companion user procedure.  The mechanisms
of passing and referencing arguments are the
same in both cases as well.
.A
Schroeder, M. D.
Saltzer, J. H.
.K
protection, protection rings, protection hardware,
access control, hardware access control, computer
utility, time-sharing, shared information, segmentation, virtual memory, Multics
.I 2378
.T
An Operating System Based on the Concept of a Supervisory Computer
.W
An operating system which is organized as a
small supervisor and a set of independent processes
are described.  The supervisor handles I/O with external
devices-the file and directory system-schedules
active processes and manages memory, handle errors, and
provides a small set of primitive functions which
it will execute for a process.  A process is able to
specify a request for a complicated action on the
part of the supervisor (usually a wait on the occurrence
of a compound event in the system) by combining
these primitives into a "supervisory computer program."
 The part of the supervisor which executes these
programs may be viewed as a software implemented "supervisory
computer."  The paper develops these concepts
in detail, outlines the remainder of the supervisor, and
discusses some of the advantages of this approach.
.A
Gaines, R. S.
.K
operating systems, supervisors, multiprogramming,
time-sharing, cooperating processes
.I 2379
.T
The Design of the Venus Operating System
.W
The Venus Operating System is an experimental
multiprogramming system which supports five or
six concurrent users on a small computer.  The system was
produced to test the effect of machine architecture
on complexity of software.  The system is defined by
a combination of microprograms and software.  The
microprogram defines a machine with some unusual architectural
feature; the software exploits these features
to define the operating system as simply as possible.
 In this paper the development of the system is
described, with particular emphasis on the principles which guided the design.
.A
Liskov, B. H.
.K
operating systems, system design, levels of abstraction,
machine architecture, microprogramming,
segments, semaphores, multiprogramming, virtual machines,
processes, process communication, virtual devices,
data sharing, resource management, deadlock
.I 2380
.T
TENEX, a Paged Time Sharing System for the PDP-10
.W
TENEX is a new time sharing system implemented
on DEC PDP-10 augmented by special paging hardware
developed at BBN.  This report specifies a set of goals
which are important for any time sharing system.
 It describes how the TENEX design and implementation
achieve these goals.  These include specifications
for a powerful multiprocess large memory virtual machine,
intimate terminal interaction, comprehensive
uniform file and I/O capabilities, and clean flexible
system structure.  Although the implementation
described here required some compromise to achieve a
system operational within six months of hardware
checkout, TENEX has met its major goals and provided
reliable service at several sites and through the
ARPA network.
.A
Bobrow, D. G.
Burchfiel, J. D.
Murphy, D. L.
Tomlinson, R. S.
Beranek, B.
.K
TENEX, paging, virtual machines, time sharing
system, scheduling algorithm, process structure,
PDP-10
.I 2381
.T
Average Binary Search Length for Dense Ordered Lists (Corrigendum)
.A
Flores, I.
Madpis, G.
.I 2382
.T
Reconstruction of Pictures from Their Projections (Corrigendum)
.A
Gordon, R.
Herman, G. T.
.I 2383
.T
Music and Computer Composition
.W
The problem discussed is that of simulating human
composition of Western popular music by computer
and some relevant theories of music and harmony are given.
 Problems with this kind of program and several
schemes that are known not to work are discussed.  Several
previous computer compositions are discussed,
including the ILLIAC Suite.  A program to generate short
melody fragments was written to simulate some
of the aspects of human composition.  Five samples of
its output are presented and discussed.  It was
discovered that although the fragments show many of
the characteristics of popular melodies, they have
a strangely alien sound.  It is theorized that this
is because the relevant probabilities which would
discriminate against unfamiliar sequences were not used.
.A
Moorer, J. A.
.K
artificial intelligence, heuristic programming,
models of cognitive processes, computer music,
computer composition, music theory
.I 2384
.T
Hidden-Line Plotting Program [J6] (Algorithm A420)
.A
Williamson, H.
.K
hidden-line plot, surface plot
.I 2385
.T
Zeros of a Complex Polynomial [C2] (Algorithm A419)
.A
Jenkins, M. A.
Traub, J. F.
.K
roots, roots of a polynomial, zeros of a polynomial
.I 2386
.T
Dynamic Microprogramming: Processor Organization
and Programming (Corrigendum)
.A
Tucker, A. B.
.I 2387
.T
Maximum Computing Power and Cost Factors in the Centralization Problem
.W
A simple analysis of some computer-economic factors
involved in comparing multimachine installations
versus large single machine installations is given, and
a mathematical model is derived to assist policy
decisions.
.A
Oldehoeft, A. E.
Halstead, M. H.
.K
centralization, decentralization, economics of
computers, computer management, economies of scale
.I 2388
.T
Optimizing Binary Trees Grown With a Sorting Algorithm
.W
Items can be retrieved from binary trees grown
with a form of the Algorithm Quicksort in an
average time proportional to log n, where n is the number
of items in the tree.  The binary trees grown
by this algorithm sometimes have some branches longer
than others; therefore, it is possible to reduce
the average retrieval time by restructuring the tree to
make the branches as uniform in length as possible.
 An algorithm to do this is presented.  The use of this
algorithm is discussed, and it is compared with
another which restructures the tree after each new item is added.
.A
Martin, W. A.
Ness, D. N.
.K
retrieving information from binary trees, global
and local optimization, sorting, recursion
.I 2389
.T
Preliminary Report on a System for General Space Planning
.W
A computer language and a set of programs within
that language are described which allow the
formulating and solving of a class of space planning
problems.  The language is an extension of Algol
and includes means to represent spaces and objects, to manipulate
them, and to test the resulting arrangements
according to a variety of constraints.  The algorithms
used to solve problems expressed in this language
rely on heuristic programming.  Both the language
and the search algorithms are detailed.
.A
Eastman, C. M.
.K
automated design, architecture, heuristic programs, space planning
.I 2390
.T
A Proposal for a Computer-Based Interactive Scientific Community
.W
Because of the problems created by the explosion
of papers in the mathematical sciences and
the drawbacks that this places on research, it is suggested
that a tree of all mathematical results and
terminology be maintained in a multiterminal computer system.
 Users of the system can store in the computer
an updated file of their current knowledge, and on selecting
a paper to read, they can obtain from the
computer the minimum subtree of theorems required to bring
them from what they already know to the background
knowledge which the paper assumes.  Under certain conditions,
means are also provided for the contribution
of useful comments by the readers of a work and for interaction
between commentators and with the author.
 This paper describes how the system can be organized
and the role required of readers, writers, and
commentators.
.A
Pager, D.
.K
interactive system, organization of scientific community,
readers, writers, commentators, computer
utility, information retrieval, trees, data structures
.I 2391
.T
Unitary Symmetric Polynomials [Z] (Algorithm R391)
.A
Schrack, G. F.
.K
symmetric polynomials, elementary symmetric polynomials,
unitary symmetric polynomials, polynomial
synthesis, reverse Horner scheme, reverse
synthetic division, binomial coefficients
.I 2392
.T
In-Situ Transposition of a Rectangular Matrix [F1] (Algorithm C380)
.A
Macleod, I. D. G.
.K
rectangular matrix, transpose
.I 2393
.T
Calculation of Fourier Integrals [D1] (Algorithm A418)
.A
Einarsson, B.
.K
quadrature, Filon quadrature, integration, Filon integration,
Fourier coefficients, Fourier integrals,
Fourier series, spline, spline approximation, spline
quadrature, extrapolation, Richardson extrapolation
.I 2394
.T
Ordering +-f(+-f(+-f(...+-f(x)..))) When f(x) Is Positive Monotonic
.A
Salzer, H. E.
.K
ordering, storage, retrieval, positive functions,
monotonic functions, increasing functions, decreasing
function, binary system, Chebyshev zeros, square rots, continued fractions
.I 2395
.T
Quadratic Programming for Nonlinear Regression
.W
A quadratic programming algorithm is described
for use with the magnified diagonal method of
nonlinear regression with linear constraints.  The
regression method is published in JACM, July 1970.
.A
Shrager, R. I.
.K
nonlinear equations, nonlinear regression, nonlinear
programming, quadratic programming, least
squares, inequality, constraints, iteration
.I 2396
.T
MUSE: A Model To Understand Simple English
.W
MUSE is a computer model for natural language
processing, based on a semantic memory network
like that of Quillian's TLC.  MUSE, from a Model to Understand
Simple English, processes English sentences
of unrestricted content but somewhat restricted format.
 The model first applies syntactic analysis to
eliminate some interpretations and then employs a simplified
semantic intersection procedure to find
a valid interpretation of the input.  While the semantic
processing is similar to TLC's, the syntactic
component includes the early use of parse trees and special
purpose rules.  The "relational triple" notation
used during interpretation of input is compatible with MUSE's
memory structures, allowing direct verification
of familiar concepts and the addition of new ones.
MUSE also has a repertoire of actions, which range
from editing and reporting the contents of its own
memory to an indirect form of question answering.
 Examples are presented to demonstrate how the model interprets
text, resolves ambiguities, adds information
to memory, generalizes from examples and performs various actions.
.A
McCalla, G. I.
Sampson, J. R.
.K
natural language processing, semantic memory, text
comprehension, question answering, artificial
intelligence, human memory simulation
.I 2397
.T
Optimizing the Polyphase Sort (Corrigendum)
.A
Shell, D. L.
.I 2398
.T
Teacher/Student Authored CAI Using the NEWBASIC System
.W
The pedagogical advantages of a general purpose
interactive system called NEWBASIC/CATALYST
are discussed.  NEWBASIC/CATALYSTincorporates an advanced
implementation of BASIC, system-level interactive
features, and a general capability for extension through
user oriented function attachment,  Application
of this last feature to provide a flexible CAI scan capability
is illustrated.  An example of interaction
at the system level shows how students can mix the advantages
of independent or "solo" mode computing
with those of guided or "dual" mode interaction.  Preliminary
experience with the system in an urban
secondary school setting is discussed.
.A
Dwyer, T. A.
.K
CAI, BASIC, CATALYST, NEWBASIC, education, computers
in education, extended languages, interactive
systems
.I 2399
.T
A CRT Editing System
.W
A test-editing and manipulation program is described.
 The program operates from low-cost cathode-ray
tube entry and display stations with keyboard and 13
function buttons. Applications, potential economy
of operation, and some aspects of implementation are discussed.
.A
Irons, E. T.
Djorup, F. M.
.K
editing, text, cathode-ray tube entry display, time-sharing
.I 2400
.T
Use of the Hough Transformation ToDetect Lines and Curves in Pictures
.W
Hough has proposed an interesting and computationally
efficient procedure for detecting lines
in pictures.  This paper points out that the use of angle-radius
rather than slope-intercept parameters
simplifies the computation further.  It also shows
how the method can be used for more general curve
fitting, and gives alternative interpretations
that explain the source of its efficiency.
.A
Duda, R. O.
Hart, P. E.
.K
picture processing, pattern recognition, line detection,
curve detection, colinear points, point-line
transformation, Hough transformation
.I 2401
.T
On Shrinking Binary Picture Patterns
.W
A parallel processing algorithm for shrinking
binary patterns to obtain single isolated elements,
one for each pattern, is presented.  This procedure
may be used for counting patterns on a matrix, and
a hardware implementation of the algorithm using large
scale integrated technology is envisioned.  The
principal features of this method are the very small
window employed (two-by-two elements), the parallel
nature of the process, and the possibility of shrinking
any pattern, regardless of the complexity of
its configuration.  Problems regarding merging and disconnection
of patterns during the process as well
as the determination of the maximum number of steps
necessary to obtain a single isolated element from
a pattern, are reviewed and discussed.  An analogy with a
neural network description, in terms of McCulloch-Pitts
"neurons" is presented.
.A
Levialdi, S.
.K
counting binary patterns, shrinking, parallel
processing, multiple connected pictures
.I 2402
.T
Pictorial Pattern Recognition and the
Phase Problem of X-ray Crystallography
.W
The availability of interactive, three-dimensional,
computer graphics systems coupled to powerful
digital computers encourages the development of algorithms
adapted to this environment.  Pictorial pattern
recognition techniques make possible a number of approaches
to X-ray structure determination based on
molecular model building, i.e. the use of chemical information
to frame "structural hypotheses" which
can computationally be tested and refined by reference
to the experimental data.  Application of standard
pattern recognition algorithms is hindered by the fact
that the cross-correlation between a model and
the correct structure cannot be computed because of
a fundamental incompleteness in the measured data.
 However, it is possible to compute an upper bound to such
a cross-correlation.  A simple example demonstrates
that this information can be the basis of a technique
for structure determination that can make effective
use of an interactive graphics system. Model building
by cross-correlations has intrinsic advantages
over usual crystallographic techniques based on the
autocorrelation or Patterson function, especially
for large structures.  This is significant, for crystallography
of biological macromolecules hasbeen
and will continue to be a field of intense interest.
.A
Lesk, A. M.
.K
pictorial pattern recognition, phase problem,
X-ray crystallography, interactive graphics
.I 2403
.T
Procedures for Natural Spline Interpolation [E1] (Algorithm A472)
.A
Herriot, J. G.
.K
approximation, interpolation, spline, natural
spline, spline approximation, cubic natural spline
.I 2404
.T
Exponential Integrals [S13] (Algorithm A471)
.A
Gautschi, W.
.K
exponential integral, recurrence relations,
recursive computation, continued fractions
.I 2405
.T
Linear Systems with Almost Tridiagonal Matrix [F4] (Algorithm A470)
.A
Kubicek, M.
.K
system of linear equations, almost tridiagonal matrix, sparse matrix
.I 2406
.T
A Data Definition and Mapping Language
.W
A data definition language i sa declarative
computer language for specifying data structures.
 Most data definition languages concentrate on the declaration
of logical data structures with little
concern for how these structures are physically realized
on a computer system.  However, the need for
data definition languages which describe both the logical
and physical aspects of data is increasingly
apparent.  Such languages will be a key systems, as well
as in advanced data management systems and distributed
data bases.  This paper reviews past work in the data
definition language for describing both logical
and physical aspects of data.  Applications of these
"generalized" data definition languages are also
discussed.
.A
Sibley, E. H.
Taylor, R. W.
.K
data definition language, data and storage structure,
data translation, data base management systems,
file translation
.I 2407
.T
Curriculum Recommendations for Undergraduate
Programs in Information Systems
.W
The need for education related to information
systems in organizations is discussed, and a
curriculum is proposed for an undergraduate program.
Material necessary for such programs is identified,
and courses incorporating it are specified.Detailed course
descriptions are presented.  Program organization
and a problems of implementation are discussed.
.A
Couger, J. D.
.K
education, undergraduate curricula, management systems,
information systems, information analysis,
system design, systems analysis
.I 2408
.T
Solving the Biharmonic Equation in a Square:
A Direct Versus a Semidirect Method
.W
Two methods for solving the biharmonic equation
are compared.  One method is direct, using
eigenvalue-eigenvector decomposition.  The other method
is iterative, solving a Poisson equation directly
at each iteration.
.A
Ehrlich, L. W.
.K
biharmonic, direct method, block iterative,
eigenvector-eigenvalue decomposition
.I 2409
.T
An Algorithm for the Approximate Solution
of Wiener-Hopf Integral Equations
.W
An explicit approximate solution is given for
an equation.  Where it is assumed that the classical
Wiener-Hopf technique may be applied.  It is furthermore
assumed that Fourier transforms are known explicitly.
 The approximate solution depends on two positive parameters.
.A
Stenger, F.
.K
integral equations, Wiener-Hopf, convolution, approximate solution
.I 2410
.T
A Recurrence Scheme for Converting from
One Orthogonal Expansion into Another
.W
A generalization of a scheme of Hamming for
converting a polynomial Pn(x) into a Chebyshev
series is combined with a recurrence scheme of Clenshaw
for summing any finite series whose terms satisfy
a three-term recurrence formula.
.A
Salzer, H. E.
.K
orthogonal expansions, series interconversion,
recurrence schemes, Hamming recurrence, Clenshaw
recurrence, three-term recurrence, five-term recurrence, Chebyshev series
.I 2411
.T
Tree-Structured Programs
.A
Wegner, E.
.K
control structures, flowcharts, goto statements,
inductive assertion, least fix points, optimization
in compilers, program documentation, program flow graphs,
programming language design, proof of programs,
semantics of programming languages, structured programming.
.I 2412
.T
Comment on Brent's Scatter Storage Algorithm
.A
Feldman, J. A.
Low, J. R.
.K
Hashing, information storage and retrieval,
scatter storage, searching, symbol table
.I 2413
.T
A Note on Subexpression Ordering in
the Execution of Arithmetic Expressions
.W
A counterexample to the supposed optimality
of an algorithm for generating schedules for trees
of tasks with unequal execution times is presented.
 A comparison with the "critical path" heuristic
is discussed.
.A
Denning, P. J.
Graham, G. S.
.K
scheduling, tree scheduling, task scheduling, multiprocessor scheduling
.I 2414
.T
Arithmetic Overa Finite Field [A1] (Algorithm A469)
.A
Lam, C.
McKay, J.
.K
algebra
.I 2415
.T
Algorithm for Automatic Numerical Integration
Over a Finite Interval [D1] (Algorithm A468)
.A
Patterson, T. N. L.
.K
automatic integration, numerical integration,
automatic quadrature, numerical quadrature
.I 2416
.T
Matrix Transposition in Place [F1] (Algorithm A467)
.A
Brenner, N.
.K
transposition, matrix operations, permutations,
primitive roots, number theory
.I 2417
.T
Four Combinatorial Algorithms [G6] (Algorithm A466)
.A
Ehrlich, G.
.K
permutations and combinations
.I 2418
.T
Student's t Frequency [S14] (Algorithm A465)
.A
Hill, G. W.
.K
Student's t statistic, density function, series approximation
.I 2419
.T
Eigenvalues of a Real, Symmetric, Tridiagonal
Matrix [F2] (Algorithm A464)
.A
Reinsch, C. H.
.K
eigenvalues, QR Algorithm
.I 2420
.T
Experiments with an Automatic Theorem-Prover
HavingPartial Ordering Inference Rules
.W
Automatic theorem-provers need to be made much
more efficient.  With this in mind, Slagle has
shown how the axioms for partial ordering can be replaced
by built-in inference rules when using a particular
theorem-proving algorithm based upon hyper-resolution and
paramodulation.  The new rules embody the transitivity
of partial orderings and the close relationship between
 predicates.  A program has been developed using
a modified version of these rules.  This new theorem-prover
has been found to be very powerful for solving
problems involving partial orderings.  This paper presents
a detailed description of the program and
a comprehensive account of the experiments that have been performed with it.
.A
Slagle, J. R.
Norton, L. M.
.K
theorem-proving, partial ordering, resolution,
hyper-resolution, P1-resolution, paramodulation,
inference rules, heuristics
.I 2421
.T
A Scan Conversion Algorithm with Reduced Storage Requirements
.W
Most graphics systems using a raster scan output
device (CRT or hardcopy) maintain a display
file in the XY or random scan format.  Scan converters,
hardware or software, must be provided to translate
the picture description from the XY format to the raster
format.  Published scan conversion algorithms
which are fast will reserve a buffer area large enough
to accommodate the entire screen.  On the other
hand, those which use a small buffer area are slow because
they require multiple passes through the XY
display file.  The scan conversion algorithm described
here uses a linked list data structure to process
the lines of the drawing in strips corresponding to
groups of scan lines.  A relatively small primary
memory buffer area is used to accumulate the binary image
for a group of scan lines.  When this portion
of the drawing has been plotted, the buffer is reused for
the next portion.  Because of the list processing
procedures used, only a single pass through the XY display
file is required when generating the binary
image and only a slight increase in execution time over
the fully buffered core results.  Results slow
that storage requirements can be reduced by more than
80 percent while causing less than a 10 percent
increase in execution time.
.A
Jordan, B. W. Jr.
Barrett, R. C.
.K
graphics, scan conversion, raster plotter,
line drawing, discrete image, dot generation
.I 2422
.T
Adaptive Correction of Program Statements (Corrigendum)
.A
James, E. B.
Partridge, D. P.
.I 2423
.T
A Parser-Generating System for Constructing Compressed Compilers
.W
This paper describes a parser-generating system
(PGS) currently in use on the CDC-6500 computer
at Purdue University.  The PGS is a Fortran-coded compiler.
 In the input translation grammar, each BNF
syntactic rule corresponds to a (possibly empty) "code
generator" realizable as an assembly language,
Fortran or Algol, subroutine that is called whenever
that syntactic rule is applied in the parse of a
program.  Typical one-pass compilers constructed by the
PGS translate source programs at speeds approaching
14,000 cards per minute.  For an XPL compiler, the parser
program and its tables currently occupy 288
words of 60-bit core memory of which 140 words are parsing
table entries and 82 words are links to code
generators.
.A
Mickunas, M. D.
Schneider, V. B.
.K
parser generators, translator writing systems,
syntactic analysis, normal-form grammars, pushdown
automata, translation grammars, translator optimization, compression algorithm
.I 2424
.T
Dynamic Verification of Operating System Decisions
.W
Dynamic verification of a decision implies
that every time the decision is made there is a
consistency check performed on the decision using independent
hardware and software.  The dynamic verification
of operating system decisions is used on the PRIME system
being designed and constructed at the University
of California, Berkeley.  PRIME is an experimental time-sharing
which is to have the properties of continuous
availability, data privacy, and cost effectiveness.
 The technique of dynamic verification allows the
construction of an operating system which does not make certain
decisions improperly even in the presence
of a single hardware or software fault.  Furthermore,
multiple faults lead to unreliable operation only
if the faults happen to reinforce each other.  On PRIME,
dynamic verification is used to ensure that
one user's information cannot become available to another
user gratuitously even in the presence of a
single hardware or software fault.the amount of additional
hardware and software required for dynamic
verification can be modest.
.A
Fabry, R. S.
.K
operating systems, data security, fault tolerance,
software reliability, data privacy, program
verification, modular computer systems
.I 2425
.T
The Programmer as Navigator
.A
Bachman, C. W.
.I 2426
.T
Algorithms SCALE1, SCALE2, and SCALE3 for Determination
of Scales on Computer Generated Plots
[J6] (Algorithm A463)
.A
Lewart, C. R.
.K
plotting, scaling for plotting
.I 2427
.T
Bivariate Normal Distribution [S15] (Algorithm A462)
.A
Donnelly,T. G.
.K
bivariate, normal Gaussian, frequency distribution
.I 2428
.T
Cubic Spline Solutions to a Class of Functional
Differential Equations [D2] (Algorithm A461)
.A
Burkowski, F. J.
Hoskins, W. D.
.K
differential equation, spline approximation
.I 2429
.T
Calculation of Optimum Parameters for Alternating
Direction Implicit Procedures [D3] (Algorithm
A460)
.A
Saylor, P. E.
Sebastian, J. D.
.K
elliptic difference equations, Peaceman-Rachford,
Douglas-Rachford, W. B. Jordan, optimum parameters,
alternating-direction-implicit, ADI
.I 2430
.T
The Elementary Circuits of a Graph [H] (Algorithm A459)
.A
Syslo,M. M.
.K
algorithm, graph theory, circuit search
algorithm, path search algorithm, searching
.I 2431
.T
Discrete Linear L1 Approximation by interval
Linear Programming [E2] (Algorithm A458)
.A
Robers, P. D.
Robers, S. S.
.K
discrete approximation, L1 approximation
.I 2432
.T
Addendum to a Multiple-Precision Division Algorithm
.A
Mifsud, C. J.
Bohlen, M. J.
.K
multiple-precision, division, overflow
.I 2433
.T
Control Structures in Illiac IV Fortran
.W
As part of an effort to design and implement
a Fortran compiler on the ILLIAC IV, an extended
Fortran, called IVTRAN, has been developed.  This language
provides a means of expressing data and control
structures suitable for exploiting ILLIAC IV parallelism.
 This paper reviews the hardware characteristics
of the ILLIAC and singles out unconventional features
which could be expected to influence language (and
compiler) design.  The implications of these features for
data layout and algorithm structure are discussed,
and the conclusion is drawn that data allocation rather than
code structuring is the crucial ILLIAC optimization
problem.  A satisfactory method of data allocation is
then presented.  Language structures to utilize
this storage method and express parallel algorithms are described.
.A
Millstein, R. E.
.K
array processing, parallelism detection, explicit
parallelism, array allocation, parallel control
structures, ILLIAC IV Fortran
.I 2434
.T
Using Page Residency To Select the Working Set Parameter
.W
Denning's method for selecting the working set
parameter, which uses interreference intervals,
is examined.  Several omissions in his model are noted,
and new assumptions are introduced to overcome
these omissions.  Using this modified model, Dening's results
on page residency are rederived and reconsidered
for selecting the working set parameter.
.A
Prieve, B. G.
.K
working set model, paging, program behavior,program modeling
.I 2435
.T
A Class of Dynamic Memory Allocation Algorithms
.W
Anew dynamic memory allocation algorithm, the
Fibonacci system, is introduced.  This algorithm
is similar to, but seems to have certain advantages over,
the "buddy" system.  A generalization is mentioned
which includes both of these systems as special cases.
.A
Hirschberg, D. S.
.K
dynamic storage allocation, buddy system,
simulation, Fibonacci, fragmentation
.I 2436
.T
A Note on the Confinement Problem
.W
This note explores the problem of confining
a program during its execution so that it cannot
transmit information to any other program except its
caller.  A set of examples attempts to stake out
the boundaries of the problem.  Necessary conditions
for a solution are stated and informally justified.
.A
Lampson, B. W.
.K
protection, confinement, proprietary program,
privacy, security, leakage of data
.I 2437
.T
General Performance Analysis of Key-to-Address
Transformation Methods Using an Abstract File
Concept
.W
This paper presents a new approach to the analysis
of performance of the various key-to-address
transformation methods.  In this approach the keys in
a file are assumed to have been selected from the
key space according to a certain probabilistic selection
algorithm.  All files with the same number of
keys selected from this key space will be suitably weighted
in accordance with the algorithm, and the
average performance of the transformation methods on
these files will be used as the potential of these
methods.  Using this analysis, methods with the same overall
performance can be classified and key distributions
partial to certain transformations can be identified.
 All this can be done analytically.  The approach
is applied to a group of transformation methods
using files whose keys are selected randomly.
.A
Lum, V. Y.
.K
hashing, hashing techniques, hashing methods, hash coding,
key transformation, key-to-address transformation,
direct addressing, randomizing, random access, scatter
storage, information retrieval, hashing analysis,
randomization performance analysis
.I 2438
.T
A Model and Stack Implementation of Multiple Environments
.W
Many control and access environment structures
require that storage for a procedure activation
exist at times when control is not nested within the
procedure activated.  This is straightforward to
implement by dynamic storage allocation with linked
blocks for each activation, but rather expensive
in both time and space.  This paper presents an implementation
technique using a single stack to hold
procedure activation storage which allows retention
of that storage for durations not necessarily tied
to control flow.  The technique has the property that,
in the simple case,it runs identically to the
usual automatic stack allocation and deallocation procedure.
 Applications of this technique to multitasking,
coroutines, backtracking, label-valued variables, and
functional arguments are discussed.  In the initial
model, a single real processor is assumed, and the implementation
assumes multiple-processes coordinate
by passing control explicitly to one another.  A multiprocessor
implementation requires only a few changes
to the basic technique, as described.
.A
Bobrow, D. G.
Wegbreit, B.
.K
control structures, environments, stack allocation,
dendrarchy, retention, dynamic storage allocation,
access environments, FUNARG problem, multitasking,
coroutines, backtracking, label-valued variables,
functional arguments, multiprocessor systems, extensible control structures
.I 2439
.T
Multiple Terminals Under User Program
Control in a Time-Sharing Environment
.W
User-written programs on the Dartmouth Time-Sharing
system can communicate with many remote
terminals simultaneously and can control the interactions
between these terminals.  Such programs can
be written using standard input and output instructions
in any language available on the system.  This
paper describes how this multiple-terminal facility
was implemented without requiring any changes in
the system executive or in any of the system's compilers or interpreters.
.A
McGeachie, J. S.
.K
DTSS, multiple terminals, remote terminals, remote
consoles, time-sharing, on-line interaction,
on-line games
.I 2440
.T
Localization of the Roots of a Polynomial (Algorithm R429)
.A
Driessen, H. B.
Hunt, E. W. LeM.
.I 2441
.T
Hidden-Line Plotting Program (Algorithm R420)
.A
Williamson, H.
.I 2442
.T
A Sparse Matrix Package (Algorithm R408)
.A
Lawrence, E. E.
.I 2443
.T
Generation of Permutations in Lexicographic Order (Algorithm R323)
.A
Roy, M. K.
.I 2444
.T
Finding All Cliques of an Undirected Graph (Algorithm A457)
.A
Bron, C.
Kerbosch, J.
.K
cliques, maximal complete subgraphs, clusters, backtracking
algorithm, branch and bound technique,
recursion
.I 2445
.T
Routing Problem (Algorithm A456)
.A
Fencl, Z.
.K
routing problem, shortest path, traveling
salesman problem, Hamiltonian circuit
.I 2446
.T
Analysis of Skew Representations of the Symmetric Group (Algorithm A455)
.A
Hunter, D. B.
Williams, J. M.
.K
symmetric group, skew representation, partition,
Young diagram, lattice permutation, binary model,
outer product
.I 2447
.T
Sard Kernels for Certain Bivariate Cubatures
.W
An error analysis for some bivariate cubatures
is given.  The remainders are obtained by the
use of Sard kernels.  Numerical results and computer
graphs are given for some of the kernel functions.
.A
Barnhill, R. E.
Pilcher, D. T.
.K
cubatures, Sard kernels, numerical integration, remainder formulas
.I 2448
.T
Reversible Execution
.A
Zelkowitz, M. V.
.K
debugging, PL/I, reversible execution, backtracking
.I 2449
.T
A Simple Technique for Structured Variable Lookup
.W
A simple technique for the symbol-table lookup
of structured variables based on simple automata
theory is presented. The technique offers a deterministic
solution to a problem which is currently handled
in a nondeterministic manner in PL/I and COBOL compilers.
.A
Gates, G. W.
Poplawski, D. A.
.K
symbol table organization, PL/I and COBOL structured variables
.I 2450
.T
Empirical Working Set Behavior
.W
The working set model for program behavior
has been proposed in recent years as a basis for
the design of scheduling and paging algorithms.  Although
the words "working set" are now commonly encountered
in the literature dealing with resource allocation, there
is a dearth of published data on program measurements,
in the hope that workers in the field might find experimental
evidence upon which to substantiate and
base theoretical work.
.A
Rodriguez-Rosell, J.
.K
virtual memory, paging, working set,
software measurement, program behavior
.I 2451
.T
Design of Tree Structures for Efficient Querying
.W
A standard information retrieval operation is
to determine which records in a data collection
satisfy a given query expressed in terms of data values.
 The process of locating the desired responses
can be represented by a tree search model.  This paper
poses an optimization problem in the design of
such trees to serve a well-specified application. The
problem is academic in the sense that ordinarily
the optimal tree cannot be implemented by means of practical
techniques.  On the other hand, it is potentially
useful for the comparison it affords between observed
performance and that of an intuitively attractive
ideal search procedure.  As a practical application
of such a model this paper considers the design of
a novel tree search scheme based on a bit vector representation
of data and shows that essentially the
same algorithm can be used to design either an ideal
search tree or a bit-vector tree.  An experimental
study of a small formatted file illustrates the concepts.
.A
Casey, R. G.
.K
tree file, information storage and retrieval, clustering,
search, data structure, data management,
query answering
.I 2452
.T
Evaluation and Selection of File Organization-A Model and System
.W
This work first discusses the factors that
affect file (data base) organization performance,
an elusive subject, and then presents a methodology, a
model and a programmed system to estimate primarily
total storage costs and average access time of several
file organizations, given a specific data base,
query characterization and device-related specifications.
 Based on these estimates, an appropriate file
structure may be selected for the specific situation.
 The system is a convenient tool to study file
structures and to facilitate as much as possible the process
of data base structure design and evaluation.
.A
Cardenas, A. F.
.K
file organization, file structures, file management,
file organization performance, file organization
model, file structure design, secondary index organization,
simulation, data base, access time, storage
requirement, data base analysis, data management
.I 2453
.T
Information Theory Applied to the Conversion
of Decision Tables to Computer Programs
.W
Using ideas from information theory, this paper
develops a heuristic algorithm that converts
a limited entry decision table to a tree structured computer
program with near minimum average processing
time.  The method is applicable to any limited entry
decision table and does not require that actions
have single rules or that the cost of testing conditions
be equal.  It is thus more general than the
previously published heuristic algorithms.  Compared
to the optimal algorithm of Reinwald and Soland,
this algorithm is easy to code and takes a much smaller
translation time; it is thus felt that it is
more useful in practice.  The algorithm is well suited for
manual conversion of decision tables to flowcharts.
.A
Ganapathy, S.
Rajaraman, V.
.K
decision tables, optimum computer programs, information measure
.I 2454
.T
Computational Algorithms for Closed Queueing
Networks with Exponential Servers
.W
Methods are presented for computing the equilibrium
distribution of customers in closed queueing
networks with exponential servers.  Expressions for
various marginal distributions are also derived.
 The computational algorithms are based on two-dimensional
iterative techniques which are highly efficient
and quite simple to implement.  Implementation considerations
such as storage allocation strategies and
order of evaluation are examined in some detail.
.A
Buzen, J. P.
.K
queueing theory, queueing networks, equilibrium
distributions, steady state distributions
.I 2455
.T
A Generalization of AVL Trees
.W
A generalization of AVL trees is proposed in
which imbalances up to (triangle shape) is a small
integer.  An experiment is performed to compare these
trees with standard AVL trees and with balanced
trees on the basis of mean retrieval time, of amount
of restructuring expected, and on the worst case
of retrieval time.  It is shown that, by permitting
imbalances of up to five units, the retrieval time
is increased a small amount while the amount of restructuring
required is decreased by a factor of ten.
 A few theoretical results are derived, including the correction
of an earlier paper, and are duly compared
with the experimental data.  Reasonably good correspondence is found.
.A
Foster, C. C.
.K
AVL trees, balanced trees, information storage and retrieval
.I 2456
.T
On the Capabilities of While, Repeat, and Exit Statements
.W
A well-formed program is defined as a program
in which loops and if statements are properly
nested and can be entered only at their beginning.  A
corresponding definition is given for a well-formed
flowchart.  It is shown that a program is well formed if
and only if it can be written with if, repeat,
and multi-level exit statements for sequence control.
It is also shown that if,while, and repeat statements
with single-level exit do not suffice.  It is also shown
that any flowcharts can be converted to a well-formed
flowchart by node splitting.  Practical implications are discussed.
.A
Peterson, W. W.
Kasami, T.
Tokura, N.
.K
well-formed program, while statement, repeat statement,
exit statement, go to statement, flowchart,
node splitting, software reliability
.I 2457
.T
Inductive Methodsfor Proving Properties of Programs
.W
There are two main purposes in this paper:
first, clarification and extension of known results
about computation of recursive programs, with emphasis
on the difference between the theoretical and
practical approaches; second, presentation and examination
of various known methods for proving properties
of recursive programs.  Discussed in detail are two
powerful inductive methods computational induction
and structural induction, including examples of their applications.
.A
Manna, Z.
Nes, S.
Vuillemin, J.
.K
recursive programs, least fixed point, computational
induction, structural induction
.I 2458
.T
Localization of the Roots of a Polynomial (Algorithm R429)
.A
Williams, E. J.
.I 2459
.T
Hu-Tucker Minimum Redundancy Alphabetic Coding Method (Algorithm R428)
.A
Byrne, J. G.
.I 2460
.T
Clenshaw-Curtis Quadrature (Algorithm R424)
.A
Good, A. J.
.I 2461
.T
Graph Plotter (Algorithm R412)
.A
Watkins, R. P.
.I 2462
.T
An Efficient Prime Number Generator (Algorithm R357)
.A
DeMorgan, R. M.
.I 2463
.T
Complex Gamma Function (Algorithm R404,C404)
.A
Andrejkova, G.
Vinar, J.
.I 2464
.T
The Complex Method for Constrained Optimization [E4] (Algorithm A454)
.A
Richardson, J. A.
Kuester, J. L.
.K
optimization, constrained optimization, Box's algorithm
.I 2465
.T
Gaussian Quadrature formulas for Bromwich's
Integral [D1] (Algorithm A453)
.A
Piessens, R.
.K
Gaussian quadrature, Bromwich's integral, complex
integration, numerical inversion of the Laplace
transform
.I 2466
.T
Enumerating Combinations of m Out of n Objects [G6] (Algorithm A452)
.A
Liu, C. N
Tang, D. T.
.K
permutations, combination
.I 2467
.T
Chi-Square quantiles [G1] (Algorithm A451)
.A
Goldstein, R. B.
.K
Chi-square, asymptotic approximation, normal
deviate, chi-square deviate, degrees of freedom
.I 2468
.T
Rosenbrock Function Minimization [E4] (Algorithm A450)
.A
Machura, M.
Mulawa, A.
.K
function minimization, Rosenbrock's method
.I 2469
.T
Petri Nets and Speed Independent design
.W
Petri nets are investigated as one method of
modeling speed independent asynchronous circuits.
 A study of circuit realizations of Petri nets leads
to a demonstration of their usefulness in modeling
speed independent operation.  This usefulness is emphasized
by the design of a speed independent processor
from modules developed in the investigation of Petri net implementation.
.A
Misunas, D.
.K
speed independent asynchronous, Petri net
.I 2470
.T
Fen-An Axiomatic Basis for Program Semantics
.W
A formal system is presented which abstracts
the notions of data item, function, and relation.
 It is argued that the system is more suitable than set
theory (or its derivatives) for the concise and
accurate description of program semantics.  It is shown
how the system can be used to build composite
data types out of simper ones with the operations of rowing,
structuring, and uniting.  It is also demonstrated
that completely new primitive types can be introduced
into languages through the mechanism of singleton
data types.  Both deterministic and nondeterministic
functions are shown to be definable in the system.
 It is described how the local environment can be modeled
as a data item and how imperative statements
can be considered functions on the environment.  The
nature of recursive functions is briefly discussed,
and a technique is presented by which they can be introduced
into the system.  The technique is contrasted
with the use of the paradoxical combinator, Y.  The
questions of local and global environments and of
various modes of function calling and parameter passing
are touched upon. The theory is applied to the
proof of several elementary theorems concerning the semantics
of the assignment, conditional, and iterative
statements.  An appendix is included which presents in
detail the formal system governing webs and fen,
the abstractions used informally in the body of the paper.
.A
MacLennan, B. J.
.K
semantics, formal systems, lambda-calculus, extensible
languages, data types, modes, axioms, correctness,
formal language definition, formal description, data structures,
description languages, models of computation
.I 2471
.T
A Learning Program Which Plays Partnership Dominoes
.W
A learning program has been written is BASIC
to play four-player partnership dominoes.  Because
dominoes is a game of incomplete information, the program
uses somewhat different principles of artificial
intelligence from those used in programs for games
of complete information, such as checkers, chess,
and go.  The program was constructed to use a "strategy
signature table" which classifies board situations
through the interactions of game parameters. Each entry
in the table contains adaptively determined
weights indicating the advi sability of various strategies.
 Once chosen, a strategy then employs probability
analysis and linear polynomial evaluation to choose
a move.  Our program wins approximately two-thirds
of its games in tournament situations, and has defeated championship players.
.A
Smith, M. H.
.K
artificial intelligence, intelligence learning,
heuristic procedures, heuristic programming, game
playing, problem solving,dominoes, incomplete information,
machine learning, signature table, learning
programs, strategy learning
.I 2472
.T
Minimal spanning Tree (Algorithm R422)
.A
Kernighan, B. W.
.K
spanning tree, minimal spanning tree, Prim algorithm
.I 2473
.T
Hidden-Line Plotting Program (Algorithm R420)
.A
Macleod, I. D. G.
Collins, A. M.
.K
hidden-line plot, surface plot
.I 2474
.T
DIFSUB for Solution of Ordinary Differential Equations (Algorithm C407)
.A
Nikolai, P. J.
.K
differential equations, stiff differential
equations, boundary value problems
.I 2475
.T
Solution of Linear Programming Problems
in 0-1 Variables [H1] (Algorithm A449)
.A
Fiala, F.
.K
linear programming, zero-one variable
.I 2476
.T
Equivalence Between AND/OR Graphs and Context-Free Grammars
.A
Hall, P. A. V.
.K
artificial intelligence, AND/OR graphs,
language theory, context-free grammars
.I 2477
.T
Multiple Exits from a Loop Without the GOTO
.A
Bochmann, G. V.
.K
control structures, goto free programming,
multiple exits from loops, exit statement
.I 2478
.T
Computer Science-Seminars for Undergraduates
.A
Kandel, A.
.K
education, computer science, curriculum, imprecise
synthesis, fuzzy educational structure
.I 2479
.T
Curriculum Recommendations for Graduate Professional
Programs in Information Systems: Recommended
Addendum on Information Systems Administration
.W
An addendum to the Report of the ACM Curriculum
Committee on Computer Education for Management
is proposed. The proposed addendum is to include in the curriculum
a course on Information Systems administration.
It is important for two reasons: (1) the systems designer
must understand the administrative framework
in which he must operate to work effectively, and (2) an
important objective of the curriculum recommendations
is to prepare the future manager of the computer activity.
 It is felt that the importance of these two
reasons justifies the addition of the recommended course.
 The course is outlined in the format of the
original report.
.A
McFarlan, F. W.
Nolan, R. L.
.K
education, management information systems, information
systems administration, information systems
management, computer management
.I 2480
.T
Teaching "About Programming"
.W
This paper presents the goals and organization
of a course about programming designed to provide
entering students in a graduate program with a cultural
enrichment in their professional lives.  The
students are expected to have taken at least two programming
courses prior to this one and, therefore,
to be familiar with at least two programming languages,
both as students and users.  Teaching someone
how to program is similar to teaching him to play a musical
instrument: neither skill can be taught-they
must be learned.  However, the teacher still serves
several vital purposes: to present a set of rules
for producing well-formed utterances; to offer numerous
demonstrations of his own skill; and to function
as an involved critic.  Finally, the teacher is the
source of information about the process in which
the student is involved.
.A
Rosin, R. F.
.K
education, programming concepts, professionalism
.I 2481
.T
The Distribution of a Program in Primary and Fast Buffer Storage
.W
A virtual memory computer system with a fast
buffer (cache) memory between primary memory and
the central processing unit is considered.  The optimal
distribution of a program between the buffer
and primary memory is studied using the program's lifetime
function.  Expressions for the distribution
of a program which maximizes the useful fraction of
the cost-time integral of primary and fast buffer
storage are obtained for swapping and nonswapping buffer management policies.
.A
Gelenbe, E.
.K
cache, virtual memory, lifetime function, cost-time integral, fast buffer
.I 2482
.T
Mixed Solutions for the Deadlock Problem
.W
Mixtures of detection, avoidance, and prevention
provide more effective and practical solutions
to the deadlock problem than any one of these alone.  The
individual techniques can be tailored for subproblems
of resource allocation and still operate together to
prevent deadlocks.  This paper presents a method,
based on the concept of the hierarchical operating
system, for constructing appropriate mixtures and
suggests appropriate subsystems for the most frequently
occurring resource allocation problems
.A
Howard, J. H. Jr.
.K
deadlocks, resource allocation, operating systems,
multiprogramming, hierarchical systems
.I 2483
.T
COKO III: The Cooper-Koz Chess Program
.W
COKO III is a chess player written entirely
in Fortran.  On the IBM 360-65, COKO III plays
a minimal chess game at the rate of .2 sec cpu time
per move, with a level close to lower chess club
play.  A selective tree searching procedure controlled
by tactical chess logistics allows a deployment
of multiple minimal game calculations to achieve some optimal
move selection.  The tree searching algorithms
are the heart of COKO's effectiveness, yet they are
conceptually simple.  In addition, an interesting
phenomenon called a tree searching catastrophe has plagued
COKO's entire development just as it troubles
a human player.  Standard exponential growth is curbed
to a large extent by the definition and trimming
of the Fischer set.  A clear distinction between tree
pruning and selective tree searching is also made.
 Representation of the chess environment is described
along with a strategical preanalysis procedure
that maps the Lasker regions.  Specific chess algorithms
are described which could be used as a command
structure by anyone desiring to do some chess program
experimentation.  A comparison is made of some
mysterious actions of human players and COKO III.
.A
Kozdrowicki, E. W.
Cooper, D. W.
.K
artificial intelligence, selective searching, tree
searching, tree searching catastrophe, heuristic
programming,chess algorithms, Lasker regions, Fischer
set, minimal chess game, strategical, tactical,
tactical control mode, game playing, alpha beta, machine
learning, concept formation, command structure,
minimax, computer chess tournament, auxiliary minimal game
.I 2484
.T
A Note on Information Organization and Storage
.W
Since the logical structure of a data base
can be represented by a tree or graph, it is quite
natural for us to view the process of designing a data
base as that of constructing a tree or a graph.
 A general method for constructing such a tree or a graph
is provided.  There are three important elements
in this general construction method; namely, a set of
binary relations, an algorithm for constructing
subsets of a set, and an algorithm for selecting an
element from the given set of objects.  The use of
different relations and algorithms results in different
information structures, as list, tree, ring,
etc.  Thus the problem of information organization and
storage is reduced to that of defining relations
and formulating algorithms under a given set of constraints.
 The results presented may be valuable to
designers as useful design concepts, and may serve as
a basis for developing a formal theory on the subject.
.A
Huang, J. C.
.K
data base, data-base management, information retrieval,
information structure, file organization,
storage allocation, tree, graph
.I 2485
.T
Managing the Computer Resource: A Stage Hypothesis
.W
Based on the study of expenditures for data processing,
a descriptive stage hypothesis is presented.
 It is suggested that the planning, organizing, and controlling
activities associated with managing the
computer resource will change in character over a period
of time, and will evolve in patterns roughly
correlated to four stages of the computer budget: Stage
I (computer acquisition), Stage II (intense system
development), Stage III (proliferation of controls), and
Stage IV (user/service orientation).  Each stage
is described and related to individual tasks for managing the computer resource.
.A
Nolan, R. L.
.K
computer management, computer budget, computer expenditures,
stage hypothesis, planning, organizing,
control, computer resource
.I 2486
.T
Computer Photocomposition of Technical Text
.W
In computer assisted typesetting by means of
photocomposition, special problems arise in highly
technical material such as mathematical formulas.  New
solutions to several of these problems have been
devised in the information system of the American Institute
of Physics.  They include: the representation
of special characters (foreign alphabets, mathematical
symbols, etc.) not available on input keyboards
or on the photocomposer; the generation of such symbols,
e.g. by overprinting; the precise positioning
of accent marks (floating diacritics); line breaks,
i.e. words or formulas placed partly at the end of
one line and partly at the beginning of the next;
and certain aspects of error correction.
.A
Alt, F. L.
Yuni Kirk, J.
.K
photocomposition, typesetting, printing, graphics, text processing
.I 2487
.T
Cubic Spline solutions to Fourth-order Boundary Value Problems
.W
The cubic spline approximation to the fourth-order
differential equation y''''+p(x)y''+q(x)y'+r(x)y=t(x)
is shown to reduce to the solution of a five-term recurrence
relationship.  For some special cases the
approximation is shown to be simply related to a finite
difference representation with a local truncation
error of order (y/720)delta^8.
.A
Hoskins, W. D.
.K
cubic spline, differential equations, boundary value problem
.I 2488
.T
Least Squares Piecewise Cubic Curve Fitting
.W
The matrices involved in a linear least squares
formulation are determined for the problem
of fitting piecewise cubic functions, those possessing
a continuous derivative, to arrays of planar data.
.A
Ferguson, J.
Staley, P. A.
.K
curve fitting, data reduction, function
approximation, approximation splines
.I 2489
.T
Number of Multiply-Restricted Partitions [A1] (Algorithm A448)
.A
Beyer, T.
Swinehart, D. F.
.K
partitions, enumeration, change making, energy-level
degeneracies, molecular vibrational energy-levels
.I 2490
.T
Efficient Algorithms for Graph Manipulation [H] (Algorithm A447)
.W
Efficient algorithms are presented for partitioning
a graph into connected components, biconnected
components and simple paths.  The algorithm for partitioning
of a graph into simple paths is iterative
and each iteration produces a new path between two
vertices already on paths.  (The start vertex can
be specified dynamically.)  If V is the number of vertices
and E is the number of edges, each algorithm
requires time and space proportional to max (V,E)
when executed on a random access computer.
.A
Hopcroft, J.
Tarjan, R.
.K
graphs,analysis of algorithms, graph manipulation
.I 2491
.T
Threaded Code
.W
The concept of "threaded code" is presented as
an alternative to machine language code.  Hardware
and software realizations of it are given.  In software
it is realized as interpretive code not needing
an interpreter.  Extensions and optimizations are mentioned.
.A
Bell, J. R.
.K
interpreter, machine code, time tradeoff, space
tradeoff, compiled code, subroutine calls, threaded
code
.I 2492
.T
The Development of Decision Tables via
Parsing of Complex Decision Situations
.W
A new parsing technique is proposed which allows
parsing based only on syntactical characteristics
of the decision problem.  It requires a description
of the problem in decision grid chart format and
allows the development of decision tables within defined
limits by avoiding, or at least minimizing,
repetition of conditions and actions in the resulting tables.
.A
Strunz, H.
.K
decision tables, parsing, decision grid chart,problem analysis
.I 2493
.T
Optimum Data Base Reorganization Points
.W
In certain data base organization schemes the
cost per access may increase due to structural
inefficiencies caused by updates.  By reorganizing
the data base the cost per access may be reduced.
 However, the high cost of a reorganization prohibits
frequent reorganizations.  This paper examines
strategies for selecting the optimum reorganization points.
.A
Shneiderman, B.
.K
data base, reorganization, files, information retrieval
.I 2494
.T
A Computer Generated Aid for Cluster Analysis
.W
A computer generated graphic method, which
can be used in conjunction with any hierarchical
scheme of cluster analysis, is described and illustrated.
 The graphic principle used is the representation
of the elements of a data matrix of similarities or dissimilarities
by computer printed symbols (of character
overstrikes) of various shades of darkness, where a
dark symbol corresponds to a small dissimilarity.
 The plots, applied to a data matrix before clustering
and to the rearranged matrix after clustering,
show at a glance whether clustering brought forth any
distinctive clusters.  A well-known set of data
consisting of the correlations of 24 psychological tests
is used to illustrate the comparison of groupings
by four methods of factor analysis and two methods of cluster analysis.
.A
Ling, R. F.
.K
computer graphics, cluster analysis, numerical
taxonomy, hierarchical clustering, factor analysis
.I 2495
.T
Adapting Optimal Code Generation for Arithmetic
Expressions to the Instruction Sets Available
on Present-Day Computers
.A
Stockhausen, P. F.
.K
arithmetic expressions, code generation, compilers,
object-code optimization, register assignment,
trees
.I 2496
.T
On the Near-Optimality of the Shortest-Latency-Time-First
Drum Scheduling Discipline
.W
For computer systems in which it is practical
to determine the instantaneous drum position,
a popular discipline for determining the sequence in which
the records are to be accessed is the so-called
shortest-latency-time-first, SLTF, discipline.  When
a collection of varying-length records is to be
accessed from specified drum positions, it is known that
the SLTF discipline does not necessarily minimize
the drum latency time.  However, we show that the total
time to access the entire collection for any
SLTF schedule is never as much as a drum revolution
longer than a minimum latency schedule.
.A
Stone, H. S.
Fuller, S.  H.
.K
drum scheduling, shortest-access-time-first, minimal
latency scheduling, shortest-latency-time-first
.I 2497
.T
Synchronizing Processors with Memory-Content-Generated Interrupts
.W
Implementations of the "Lock-Unlock" method
of synchronizing processors in a multiprocessor
system usually require uninterruptable, memory-pause type instructions.
 An interlock scheme called read-interlock,
which does not require memory-pause instructions, has
been developed for a dual DEC PDP-10 system with
real-time requirements.  The read-interlock method does
require a special"read-interlock" instruction
in the repertoire of the processors and a special "read-interlock"
cycle in the repertoire of the memory
modules.  When a processor examines a "lock" (a memory
location) with a read-interlock instruction, it
will be interrupted if the lock was already set; examining
a lock immediately sets it if it was not already
set (this event sequence is a read-interlock cycle).
Writing into a lock clears it.  Having the processor
interrupted upon encountering a set lock instead of
branching is advantageous if the branch would have
resulted in an effective interrupt.
.A
Hill, J. C.
.K
interrupts,supervisors, monitors, debugging, parallel
processing, associative memories, microprogramming
.I 2498
.T
Minimizing Wasted Space in Partitioned Segmentation
.W
A paged virtual memory system using a finite
number of page sizes is considered.  Two algorithms
for assigning pages to segments are discussed.  Both
of these algorithm are simple to implement.  The
problem of choosing the page sizes to minimize the expected
value of total wasted space in internal fragmentation
and in a page table, per segment, is then solved for a
probability density function of segment size which
may be expressed as a convex combination of Erlang densities.
.A
Gelenbe, E.
.K
dynamic storage allocation, virtual memory, paging,
multiple page sizes, fragmentation, segmentation
.I 2499
.T
Efficient Multiprogramming Resource Allocation and Accounting
.W
Although sometimes thought of as only a component
of time-sharing operation, multiprogramming
can involve broader questions of resource allocation,
since fairness is not required to meet a response
criterion.  In a multiprogrammed system, it may serve
maximal resource use to be unfair, for example
by holding an input/output channel idle for a program
while it completes a small amount of processor
usage, enabling further use of the channel.  Several
applications of this principle are given, and it
is suggested that a multiprogramming executive might
dynamically adjust its allocation algorithms to
gain efficiency.  Allocation of resources is closely connected
to accounting for those resources, raising
the problems of repeatability, minimal uncharged overhead,
and relative weighting of charges for dependent
resources.  Since weightings may depend on allocation
algorithms, these are not arbitrary accounting
parameters.  Often the only repeatable accounting is
one which omits an extensive overhead will be paid,
and should multiprogramming prove efficient, overcharges
will result.  Multiprogramming turns on allocation
of the memory resource essential to control of other
resources.  The general suggestions for allocation
and accounting are applied to this question, and some
details provided for the case of a monitor which
controls a virtual-memory machine.
.A
Hamlet, R. G.
.K
monitor, executive, multiprogramming, efficiency,
resource allocation, resource accounting
.I 2500
.T
A Practical Approach to Managing Resources and Avoiding Deadlocks
.W
Resource scheduling and allocation can be expensive
with regard to time and space in multiprogramming
or time-sharing environments involving large numbers of
tasks and resources with conflicting requirements.
 Detection and/or prevention of deadlocks can require
massive amounts of additional overhead if efficient
usage of resources is to be maintained.  A resource
management program is described which uses linked
lists along with other techniques to overcome a large
portion of this overhead.  The program, which is
currently running as part of a large scale general purpose
operating system, keeps resources relatively
active but does not detect or prevent all deadlocks
in its implemented state.  Certain changes, which
would permit more comprehensive levels of deadlock
prevention/detection at additional cost, have not
been incorporated in the running system due
to the infrequency of deadlock situations.
.A
Frailey, D. J.
.K
deadlock, resource allocation, scheduling, resource
management, multiprogramming, time-sharing,
multiprocessing, deadly embrace
.I 2501
.T
WYLBUR: An Interactive Text Editing and Remote Job Entry System
.W
WYLBUR is a comprehensive system for manipulating
all kinds of text, such as computer programs,
letters, and manuscripts, using typewriter terminals
connected to a computer.  It has facilities for
remote job entry and retrieval as well as facilities
for text alignment and justification.  A powerful
method for addressing text by content is provided.  This
paper describes the external appearance of WYLBUR
as well as its internal structure.  A short description
of the major features of ORVYL, a general purpose
time-sharing system which operates in conjunction with WYLBUR, is also included.
.A
Fajman, R.
Borgelt, J.
.K
text editing, time-sharing, on-line text editing,
interactive text editing, terminal, remote terminal,
terminal system, interactive terminal, remote job entry,
remote job retrieval, program preparation, document
preparation, data entry, content addressing
.I 2502
.T
A Comment on the Practical Aspects of Computer Science Education
.A
Estell, R. G.
.K
education, computer engineering, computer
sciences curriculum, systems design
.I 2503
.T
Another Comment on Computer Music
.A
Wexelblat, R. L.
.I 2504
.T
Concerning Music and Computer Composition in Computational Linguistics
.A
McMorrow, C. H.
.K
artificial intelligence, heuristic programming,
models of cognitive processes, computer music,
computer composition,music theory
.I 2505
.T
Reflection-Free Permutations, Rosary Permutations,
and Adjacent Transposition Algorithms
.A
Roy, M. K.
.K
permutation, permutation generation, scheduling, combinatorial analysis
.I 2506
.T
A Sparse Matrix Package (Algorithm R408)
.A
Sale, R. H. J.
.K
matrix, sparse matrix, matrix manipulation, Fortran standards
.I 2507
.T
Exact Solution of Linear Equations Using
Residue Arithmetic (Algorithm R406)
.A
Howell, J.
.K
residue arithmetic, symmetric residue, modulus,
mixed-radix representation, symmetric mixed-radix
representation, mixed radix conversion, prime number,
linear equations, Gaussian elimination, matrix
inversion, determinant, adjoint matrix, ill-condition
.I 2508
.T
Increasing the Efficiency of Quicksort (Algorithm R402)
.A
Wheeler, R. E.
.K
sorting, quicksort
.I 2509
.T
Minit Algorithm for Linear Programming (Algorithm R333)
.A
Obradovic, D.
.I 2510
.T
Minit Algorithm for Linear Programming (Algorithm R333)
.A
Holmgren, B.
Obradovic, D.
Kolm, A.
.I 2511
.T
Maxflow (Algorithm R324)
.A
Bayer, G.
.I 2512
.T
Coulomb Wave Functions (Algorithm R300)
.A
Vos, H.
.K
Coulomb wave functions, wave functions,
special functions, function evaluation
.I 2513
.T
A Nonrecursive List Moving Algorithm
.W
An efficient, nonrecursive algorithm is given
for moving any LISP-type list.  In particular,
the algorithm requires no storage other than the new
nodes into which the list is to be moved, and no
additional bits per node for marking; the algorithm
runs in time proportional to the number of nodes
in the list.  The original list structure is destroyed as it is moved.
.A
Reingold, E. M.
.K
list moving, list copying, list traversal, garbage collection LISP
.I 2514
.T
An Array Grammar Programming System
.W
A package of Fortran programs has been developed
that permits a user to interactively design
and test array grammars.  The user can control the rule
selection procedure in a derivation or parse,
using weighted programming matrices; he also has a choice
of instance selection schemes (raster,random,
parallel).  Examples are given involving array languages
consisting of simple geometrical patterns, as
well as a language of "neuron pictures."
.A
Mercer, A.
Rosenfeld, A.
.K
picture grammars, array grammars
.I 2515
.T
Minimal Event-Node Network of Project Precedence Relations
.W
A procedure for constructing a minimal event-node
network to represent a set of precedence
relations without parallel activities is presented.  A
minimal event-node network is an event-node network
in which both the number of nodes and the number of arcs
are the minima to preserve the given precedence
relations Counterexamples are given to show that the
algorithm presented by A. C. Fisher, J. S. Liebman,
and G. L. Nemhauser (1968) produces event-node networks
which are not minimal.  Since our procedure includes
the set-covering problem, the time required may grow
exponentially with the number of given activities.
.A
Corneil, D. G.
Gotlieb, C. C.
Lee, Y. M.
.K
network, project, event-node network, activity-node
network, minimal event-node network, dummy
activity, project precedence relations
.I 2516
.T
Hierarchical Storage in Information Retrieval
.W
A probabilistic analysis is employed to determine
the effect of hierarchical storage organizations
on information retrieval operations.  The data storage
hardware is assumed to consist on n-levels of
linearly connected memory hardware with increasing data
access times and increasing data storage capabilities.
 A system might, for example, consist of fast semiconductor
memory, computer core memory, extended core
storage, disk memory, and data cells.  Equations are derived
to predict the effect of such a system on
data access times using sequential files, random access files,
and structured files employing multiple-hierarchical
linked lists.
.A
Salasin, J.
.K
information retrieval, hierarchical storage
.I 2517
.T
Some Comments on the Use of Ambiguous Decision
Tables and Their Conversion to Computer Programs
.W
This paper comments upon recently published
work on decision table translation using methods
similar to the rule-mask technique.  The applicability
of these methods under various possible conventions
on overall table meaning is discussed, and it is argued
that there is a place both for the multi-rule
and the single-rule (or action set) convention in decision tale usage.
.A
King, P. J. H.
Johnson, R. G.
.K
decision tables, systems analysis, programming
.I 2518
.T
Programming by Questionnaire: An Effective Way To Use Decision Tables
.W
Programming by questionnaire combines aspects
of decision table programming and general purpose
programming by using decision tables to construct an application
program through the selection of certain
source statements from a predefined file.  It is proposed
that programming by questionnairies a useful
compromise between general and special purpose programming
for a significant class of large scale problems.
 The elements of the approach are discussed
an existing application is described.
.A
Low, D. W.
.K
customizing, modeling, applications development,
programmer productivity, simulator generation,
automatic program generation, no reprogramming
.I 2519
.T
On the Problem of Communicating Complex Information
.W
The nature of the difficulty involved in communicating
mathematical results between scientists
using a computer based information retrieval system
is examined.  The problem is analyzed in terms of
psychological and information-processing processes, and
what turns out to be a vicious circle of effects
is described.  These include ways of augmenting written
natural language by various notational and linguistic
devices, the exhibition of the structure inherent in the
information we are communicating, and a sophisticated
interactive system controlled by computer.
.A
Pager, D.
.K
complex information, information, communication,
mathematics, proof, interactive system, language
.I 2520
.T
Greatest Common Divisor of n Integers and Multipliers (Algorithm C386)
.A
Ragland, L. C.
Good, D. I.
.K
proof of algorithms, greatest common divisor,
Euclidean algorithm, inductive assertion method
.I 2521
.T
Ten Subroutines for the Manipulation
of Chebyshev Series [C1] (Algorithm A446)
.A
Broucke, R.
.K
Chebyshev series, differentiation, integration,
curve fitting,approximations, negative powers
.I 2522
.T
The Design, Implementation, and Evaluation of a Working Set Dispatcher
.W
The behavior of a computer system is largely
dependent upon the algorithms employed to allocate
the system resources to the processes competing for them.
 Recent research in time-sharing paging systems
has developed the working set model for program behavior,
and are source allocation strategy based on
this model has been proposed.  Two implementations
along these principles have been reported, but it
seems that in neither case have further results been
announced.  This report discusses the design and
implementation of a dispatcher based on the working set
principle, presents data to permit analysis of
its behavior, and indicates future directions of research
on methods of controlling a computer system.
.A
Rodriguez-Rosell, J.
Dupuy, J. P.
.K
working set, dispatcher, scheduler, time-sharing
systems, resource allocation, software evaluation,
operating systems, supervisory systems
.I 2523
.T
A Region Coloring Technique for Scene Analysis
.W
A method of converting a picture into a "cartoon"
or "map" whose regions correspond to differently
textured regions is described.  Texture edges in the
picture are detected, and solid regions surrounded
by these (usually broken) edges are "colored in" using
a propagation process.  The resulting map is cleaned
by comparing the region colors with the textures of
the corresponding regions in the picture, and also
by merging some regions with others according to criteria
based on topology and size.  The method has
been applied to the construction of cloud cover maps
from cloud cover pictures obtained by satellites.
.A
Strong III, J. P.
Rosenfeld, A.
.K
picture processing, scene analysis, edge detection
.I 2524
.T
Some Approaches to Best-Match File Searching
.W
The problem of searching the set of keys in
a file to find a key which is closest to a given
query key is discussed.  After "closest," in terms of
a metric on the the key space, is suitably defined,
three file structures are presented together with their
corresponding search algorithms, which are intended
to reduce the number of comparisons required to achieve
the desired result. These methods are derived
using certain inequalities satisfied by metrics and by
graph-theoretic concepts.  Some empirical results
are presented which compare the efficiency of the methods.
.A
Burkhard, W. A.
Keller, R. M.
.K
matching, file structuring, file searching, heuristics, best match
.I 2525
.T
A Statistical Study of the Accuracy of Floating Point Number Systems
.W
This paper presents the statistical results
of tests of the accuracy of certain arithmetic
systems in evaluating sums, products and inner products,
and analytic error estimates for some of the
computations.  The arithmetic systems studied are 6-digit
hexadecimal and 22-digit binary floating point
number representations combined with the usual chop
and round modes of arithmetic with various numbers
of guard digits, and with a modified round mode with guard
digits.  In a certain sense, arithmetic systems
differing only in their use of binary or hexadecimal number
representations are shown to be approximately
statistically equivalent inaccuracy.  Further, the
usual round mode with guard digits is shown to be
statistically superior in accuracy to the usual chop
mode in all cases save one.  The modified round
mode is found to be superior to the chop mode in all cases.
.A
Kuki, H.
Cody, W. J.
.K
error analysis, floating point arithmetic,
rounding, guard digits, number representation
.I 2526
.T
Asymmetric Memory Hierarchies
.W
 A study is presented of some of the system
implications of memory hierarchies in which the
backing or secondary store has a very small read time,
relative of both the time required for writing
and to the read time of conventional backing storage
devices. Several analytic models are introduced,
and it is shown that such hierarchies may operate in
ways which differ from those of more conventional
hierarchies.  In particular, it is shown that it may not
be necessary to multiprogram in such a situation.
 In the past, backing storage devices have been roughly
symmetric with respect to their read and write
times.  This situation may not continue, as several
devices are currently under development which may
have a very small read-time/write-time ratio.  This study
places particular emphasis on one such system-the
RCA read/write holographic optical memory.
.A
Williams, J.G.
.K
asymmetric memory hierarchy, demand paging, holographic
optical memory, memory device, memory hierarchy,
paging, storage device, storage hierarchy, virtual memory
.I 2527
.T
Implementation of High Level Language Machine
.W
Computing machines which directly execute
the statements of a high level language have been
proposed in the past.  This report describes the actual
implementation of such a machine: it is a computer
whose "machine language" is APL.  The machine is fully
operational and correctly executes almost all
of the APL operations on scalars, vectors, and arrays.
 The machine automatically allocates memory, executes
statements, calls functions, converts numbers from one
type to another, checks subscripts, and automatically
detects many types of programmer errors.
.A
Hassitt, A.
Lageschulte, J. W.
Lyon, L. E.
.K
computer architecture, high level language machine,
emulators, microprogramming, interpreters,
execution speed, APL
.I 2528
.T
Binary Pattern Reconstruction from Projections [Z] (Algorithm R445)
.A
Lau, J.
.K
pattern reconstruction, image reconstruction,
data compression, picture processing
.I 2529
.T
Binary Pattern Reconstruction from Projections [Z] (Algorithm A445)
.A
Chang, S.
.K
pattern reconstruction, image reconstruction,
data compression, picture processing
.I 2530
.T
An Algorithm for Extracting Phrases in
a Space-Optimal Fashion [Z] (Algorithm A444)
.A
Wagner, R. A.
.K
information retrieval, coding, text compression
.I 2531
.T
Graduate Education: The Ph.D. Glut
.A
Payne, W. H.
.K
graduate education, Ph.D. production, accreditation
.I 2532
.T
On Harrison's Substring Testing Technique
.A
Bookstein, A.
.K
string, substring, hashing, information storage and retrieval
.I 2533
.T
Gray Code and the +- Sign Sequence when
+-f (+-f(+-f(...+-f(x)...))) Is Ordered
.A
Salzer, H. E.
.K
Gray code, sign sequences, ordering, positive
monotonic functions, binary system, Galois sum
.I 2534
.T
Design and Implementation of a Diagnostic Compiler for PL/I
.W
PL/C is a compiler for a dialect for PL/I.  The
design objective was to provide a maximum degree
of diagnostic assistance in a batch processing environment.
 For the most part this assistance is implicit
and is provided automatically by the compiler. The most remarkable
characteristic of PL/C is its perseverance-it
completes translation of every program submitted and
continues execution until a user-established error
limit is reached. This requires that the compiler repair
errors encountered during both translation
and execution, and the design of PL/C is dominated by
this consideration.  PL/C also introduces several
explicit user-controlled facilities for program testing.
 To accommodate these extensions to PL/I without
abandoning compatibility with IBM compiler PL/C permits
"pseudo comments"-constructions whose contents
can optionally be considered either source test or comment.
 In spite of the diagnostic effort PL/C is
a fast and efficient processor.  It effectively demonstrates
that compilers can provide better diagnostic
assistance than is customarily offered, even when a sophisticated
source language is employed, and that
this assistance need not be prohibitively costly.
.A
Conway, R. W.
Wilcox, T. R.
.K
compilers, debugging, PL/I, programming languages
.I 2535
.T
The Effects of Multiplexing on a Computer-Communications System
.W
A study is made of the way in which asynchronous
time division multiplexing changes the stochastic
nature of the arrival process from a user to the computer
and, consequently, affects the performance
of a time-shared computer-communications system.  It is
concluded that while, for certain values of system
parameters, there is noticeable improvement in the
performance of the computer (model), in the sense
that time-shared scheduling delays are reduced, these
improvements are offset by the transmission delays
imposed by multiplexing so that there may be little or
no change in the computer-communications system
performance.  Analytical and simulation results are
based on the model of the computer-communications
system being an M/D/1 queue (the multiplexor) in tandem
with a single exponential server (the computer).
 Analytical results include a general description of the
output process of an M/D/1 queue and the conditions
under which this output process is approximately Poisson.
.A
Pack, C. D.
.K
computer communications, time-sharing, multiplexing,
scheduling algorithms, operating systems
.I 2536
.T
Telecommunications Using a Front-End Minicomputer
.W
The use of a front-end minicomputer to provide
varied remote terminal access to a large scale
computer is considered.  The problems of embedding
telecommunications I/O within an operating system
are discussed, and it is shown how the decentralization
of intelligence acquired by front-end processing
vastly simplifies the problem.  A specific implementation is
discussed with emphasis on the main processor-minicomputer
link, the hardware-software implementation, the effect
of the main processor operating system, and an
assessment of the advantages over a hard wired line controller.
.A
Feinroth, Y.
Franceschini, E.
Goldstein, M.
.K
telecommunications, minicomputer, front-end
processor, remote job entry, remote terminals
.I 2537
.T
Common Phrases and Minimum-Space Text Storage
.W
A method for saving storage space for text
strings, such as compiler diagnostic messages, is
described.  The method relies on hand selection of a
set of text strings which are common to one or more
messages.  These phrases are then stored only once.
The storage technique gives rise to a mathematical
optimization problem: determine how each message should
use the available phrases to minimize its storage
requirement.  This problem is nontrivial when phrases
which overlap exist.  However, a dynamic programming
algorithm is presented which solves the problem in time
which grows linearly with the number of characters
in the text.  Algorithm 444 applies to this paper.
.A
Wagner, R. A.
.K
diagnostic messages, error messages, common phrases,
minimum space, text storage, optimization,
dynamic programming
.I 2538
.T
A Computer Science Course Program for Small Colleges
.W
The ACM Subcommittee on Small College Programs
of the Committee on Curriculum in Computer Science
(CCCS) was appointed in 1969 to consider the unique
problems of small colleges and universities, and
to make recommendations regarding computer science programs
at such schools.  This report, authorized
by both the subcommittee and (CCCS), supplies a set of
recommendations for courses and necessary resources.
 Implementation problems are discussed, specifically
within the constraints of limited faculty and for
the purposes of satisfying a wide variety of objectives.
 Detailed description of four courses are given;
suggestions are made for more advanced work;
and an extensive library list is included.
.A
Austing, R. H.
Engel, G. L.
.K
computer science education, course proposals, small
colleges, programming course, social implications
course, computer organization course, file organization course, bibliographies
.I 2539
.T
Solution of the Transcendental Equation w*exp(w)=x [C5] (Algorithm A443)
.A
Fritsch, F. N.
Shafer, R. E.
Crowley,W. P.
.K
transcendental function evaluation, solution of transcendental equation
.I 2540
.T
Properties of the Working Set Model (Corrigendum)
.A
Denning, P. J.
Schwartz, S. C.
.I 2541
.T
An Overview of the ISPL Computer System Design
.W
This paper explores the advantages of the concurrent
design of the language, operating system,
and machine (via microcode) to create an interactive programming
laboratory.  It describes the synergistic
effect that the freedom to move and alter features from
one of these domains to another has had on the
design of this system (which has not been implemented).
 This freedom simplified both incremental compilation
and the system's addressing structure, and centralized the
communication mechanisms enabling the construction
of hierarchical subsystems.  It also suggested an important
new concept for operating systems: separation
of the scheduling from the maintenance functions in resource
allocation. This separation enables incorporation
of new scheduling algorithms (decision of what to do) without
endangering the system integration (correctly
performing the scheduling decisions).
.A
Balzer, R. M.
.K
concurrent design, operating-system, scheduling,
interprogram communication, incremental compilation,
virtual addressing, debugging, hierarchical subsystems
.I 2542
.T
A Software Design and Evaluation System
.W
A critical failure of current software system
design and implementation methodology is that
the performance of a proposed design is not evaluated
before it is actually implemented.  In this paper
the reasons for this failure are explored, and a new methodology
which overcomes many of the difficulties
is proposed.  A system which integrates performance evaluation
with design and implementation is described.
 This system is based on a simple, high level language
which is used to describe the evolving system
at all stages of its development.  The source language
description is used as direct input to performance
analysis and simulation routines.  Using the performance
information obtained from these routines as
feedback, the problems which adversely affect performance
are detected early enough so that they can
be corrected without costly major reimplementation of the proposed system.
.A
Graham, R. M.
Clancy, G. J. Jr.
DeVaney, D. B.
.K
operating system development, language processing
software evaluation, compilers, system programming,
supervisory systems, debugging, program maintenance,
modeling, system integration, simulation
.I 2543
.T
Reducing the Retrieval Time of Scatter Storage Techniques
.W
A new method for entering and retrieving information
in a hash table is described.  The method
is intended to be efficient if most entries are looked
up several times.  The expected number of probes
to look up an entry, predicted theoretically and verified
by Monte Carlo experiments, is considerably
less than for other comparable methods if the table
is nearly full.  An example of a possible Fortran
implementation is given.
.A
Brent, R. P.
.K
address calculation, content addressing, file searching,
hash addressing, hash code, linear probing,
linear quotient method, scatter storage, searching, symbol table
.I 2544
.T
Automatic Error bounds for Simple Zeros of Analytic Functions
.W
The Cauchy-Ostrowski theorem on convergence
of Newton iterates for an analytic function in
one variable is extended to include computational errors
using complex interval arithmetic. Several numerical
examples are given for polynomials with real and complex
roots and one example for the Bessel function
of the first kind.
.A
Rokne, J.
.K
real intervals, complex intervals, real interval
arithmetic, complex interval arithmetic, Newton's
method, Cauchy-Ostrowski theorem, zeros of
polynomials, zeros of Bessel functions
.I 2545
.T
A Theory of Discrete Patterns and Their Implementation in SNOBOL4
.W
The notion of a discrete pattern is formalized
and certain properties deduced.  A pattern is
shown to be a generalization of a formal language.
Algorithms for implementing the kinds of patterns
in SNOBOL4 are given.  The general approach is to create,
in-so-far as possible, a bottom-up parse from
a top-down specification.
.A
Gimpel, J. F.
.K
patterns, SNOBOL4, pattern theory, parsing, pattern matching,
string processing, pattern implementation
.I 2546
.T
The Use of Grammatical Inference for Designing Programming Languages
.W
Both in designing a new programming language
and in extending an existing language, the designer
is faced with the problem of deriving a "natural" grammar
for the language.  We are proposing an interactive
approach to the grammar design problem wherein the designer
presents a sample of sentences and structures
as input to a grammatical inference algorithm.  The algorithm
then constructs a grammar which is a reasonable
generalization of the examples submitted by the designer.
 The implementation is presently restricted
to a subclass of operator precedence grammars, but
a second algorithm is outlined which applies to a
larger class of context-free grammars.
.A
Crespi-Reghizzi, S.
Melkanoff, M. A.
Lichten, L.
.K
grammar design, language definition, inference,
identification in the limit, extensible languages
.I 2547
.T
Representation of Contours ad Regions for Efficient Computer Search
.W
A novel computer-searchable representation
for the three basic pictorial features, contour
maps, region coverage, and line structures, is described.
 The representation, which has practical storage
requirements, provides a rapid mean of searching large
files for data associated with geometric position
as well as with attribute value.  An application of this
representation to handling terrain information
illustrates its utility.  The algebraic properties
of the data structure make it computationally easy
to determine whether a point lies within a closed boundary;
compute the area contained by a closed boundary;
generate the closed boundary representing the union or
intersection of two closed boundaries; and determine
the neighboring boundaries to a point and the
minimum distances between them and the point.
.A
Merrill, R. D.
.K
contour map representation, region boundary representation,
computer-search-able structure, graphic
data retrieval, graphic language, two-dimensional
patterns, computer graphics, graphic display
.I 2548
.T
Normal Deviate [S14] (Algorithm A442)
.A
Hill, G. W.
Davis, A. W.
.K
normal distribution inverse, probit
transform, Taylor series approximation
.I 2549
.T
Random Deviates from the Dipole Distribution [G5] (Algorithm A441)
.A
Knop, R. E.
.K
random number, probability density, probability distribution,
Dipole distribution, Cauchy distribution,
simulation, Monte Carlo
.I 2550
.T
A Multidimensional Monte Carlo Quadrature with
Adaptive Stratified Sampling [D1] (Algorithm A440)
.A
Gallaher, L. J.
.K
Monte Carloquadrature, stratified sampling,
adaptive quadrature, sequential stratification
.I 2551
.T
Mutual Recursion in Algol 60 Using Restricted Compilers
.A
Atkins,M. S.
.K
Algol 60, mutual recursion, compiler restrictions
.I 2552
.T
A Note on When To Chain Overflow Items Within a Direct-Access Table
.A
Bays, C.
.K
hash code, open hash, chaining, information retrieval, collision
.I 2553
.T
The Practical Aspect of Computer Science Education-Discussion
.A
Blount, S. E.
.K
education, computer engineering, computer
science curriculum, systems design
.I 2554
.T
Reduction of a Band-Symmetric Generalized Eigenvalue Problem
.W
An algorithm is described for reducing the
generalized eigenvalue problem Ax = lambda Bx to
an ordinary problem, in case A and B are symmetric band
matrices with B positive definite.  If n is the
order of the matrix and m the bandwidth, the matrices
A and B are partitioned into m-by-m blocks; and
the algorithm is described in terms of these blocks.
 The algorithm reduces the generalized problem to
an ordinary eigenvalue problem for a symmetric band
matrix C whose bandwidth is the same as A and B.
 The algorithm is similar to those of Rutishauser and
Schwartz for the reduction of symmetric matrices
to band form.  The calculation C requires order mn^2
operation.  The round-off error in the calculation
of C is of the same order as the sum of the errors at
each of the n/m steps of the algorithm, the latter
errors being largely determined by the condition of B with respect to inversion.
.A
Crawford, C. R.
.K
generalized eigenvalues, symmetric band matrices
.I 2555
.T
Variable-Precision Exponentiation
.W
A previous paper presented an efficient algorithm,
called the Recomputation Algorithm, for
evaluating a rational expression to within any desired tolerance
on a computer which performs variable-precision
arithmetic operations.  The Recomputation Algorithm can be
applied to expressions involving any variable-precision
operations having O(10^(-p) + SUM{|Ei|}) error bounds,
where p denotes the operation's precision and
Ei denotes the error in the operation's ith argument.
 This paper presents an efficient variable-precision
exponential operation with an error bound of the above
order.  Other operations such as log, sin, and
cos, which have simple series expansions, can be handled similarly.
.A
Richman, P. L.
.K
variable-precision, exponential function,
error analysis, interval arithmetic
.I 2556
.T
Adaptive Correction of Program Statements
.W
A method of analyzing statements in a programming
language which can tolerate a considerable
inaccuracy in their specification is proposed. This method
involves principles at present mainly confined
to studies in the area of artificial intelligence such
as feature extraction, approximate tree matching,
and strategy improvement by feedback from the matching process.
 A pilot program incorporating the principles
is described and preliminary operating results are presented.
 A final section surveys further principles
which are currently being investigated.
.A
James, E. B.
Partridge, D. P.
.K
adaptive, linguistic pattern matching, automatic
parsing, approximate match, compiler, program
statement analysis, syntax analysis
.I 2557
.T
On the Time Required for a Sequence of Matrix Products
.W
This paper discusses the multiplication of conformable
sequences of row vectors, column vectors,
and square matrices.  The minimum time required to evaluate
such products on ordinary serial computers
as well as parallel computers is discussed.  Algorithms
are presented which properly parse such matrix
sequences subject to the constraints of the machine organization.
.A
Muraoka, Y.
Kuck, D. J.
.K
matrix expressions, matrix multiplication, operation
minimization, parallel machine, time minimization
.I 2558
.T
Protection in Programming Languages
.W
Linguistic mechanisms which can be used to protect
one subprogram from another's malfunctioning
are described.  Function-producing functions and various
type-tagging schemes are considered.  An attempt
is made to distinguish between access limitation and authentication.
.A
Morris, J. H. Jr.
.K
protection, types, environments,trademarks, seals,
access keys, access control authentication,
secrecy
.I 2559
.T
The Reallocation of Hash-Coded Tables
.W
When the space allocation for a hash-coded table
is altered, the table entries must be rescattered
over the new space.  A technique for accomplishing
this rescattering is presented.  The technique is
independent of both the length of the table and the hashing
function used, and can be utilized in conjunction
with a linear reallocation of the table being rescattered.
 Moreover, it can be used to eliminate previously
flagged deletions from any hash-coded table, or to change
from one hashing method to another.  The efficiency
of the technique is discussed and theoretical statistics are given.
.A
Bays, C.
.K
reallocation, dynamic storage, hash code, scatter storage, deletions
.I 2560
.T
A Queuing Model of a Multiprogrammed
Computer with a Two-Level Storage System
.W
The results are presented of an analysis of
a probabilistic model of a multiprogrammed computer
system with a two-level storage system in which there
is sequential dependency of accesses between the
devices.  Expressions are obtained for the long-run probability
that both the CPU and each of the storage
devices are busy.  Some numerical results are given which
quantify the gains in CPU utilization obtainable
by multiprogramming in the presence of this type of storage system.
.A
Shedler, G. S.
.K
multiprogrammed computer system, storage system, hierarchical index sets
.I 2561
.T
A Heuristic Approach to Inductive Inference in Fact Retrieval Systems
.W
Heuristic procedures are presented which have
been developed to perform inferences by generalizing
from available information.  The procedures make use
of a similarity structure which is imposed on the
data base using nonnumerical clustering algorithms.  They
are implemented in a model fact retrieval system
which uses a formal query language and a property-list data
structure.  A program of experiments is described
wherein the procedures are used with test data bases
which are altered by deleting part of the data and
by purposely introducing false data.  It is found that
the system can infer the correct response under
a variety of conditions involving incomplete and inconsistent data.
.A
Skinner, C. W.
.K
inference, inductive inference, clustering, fact retrieval, heuristics
.I 2562
.T
Routing Problem (Algorithm R456)
.A
Tesch, G.
.I 2563
.T
Merge Sort Algorithm (R426)
.A
Bron, C.
.I 2564
.T
Hidden-Line Plotting Program (Algorithm R420)
.A
Ellis, T. M. R.
.I 2565
.T
A Gaussian Pseudo-Random Number Generator (Algorithm 488)
.A
Brent, R. P.
.K
random numbers, pseudo-random numbers,
Gaussian distribution, normal distribution
.I 2566
.T
Exact Cumulative Distribution of the Kolmogorov-Smirnov
Statistic for Small Samples (Algorithm
A487)
.A
Pomeranz, J.
.K
Kolmogorov-Smirnov test, K-S statistic, goodness-of-fit testing
.I 2567
.T
An Exponential Method for the Solution of
Systems of Ordinary Differential Equations
.W
An explicit, coupled, single-step method for
the numerical solution of initial value problems
for systems of ordinary differential equations is presented.
 The method was designed to be general purpose
in nature but to be especially efficient when dealing
with stiff systems of differential equations.
It is, in general, second order except for the case
of a linear system with constant coefficients and
linear forcing terms; in that case, the method is third
order.  It has been implemented and put to routine
usage in biological applications-where stiffness frequently
appears-with favorable results.  When compared
to a standard fourth order Runge-Kutta implementation,
computation time required by this method has ranged
from comparable for certain nonstiff problems to better
than two orders of magnitude faster for some
highly stiff systems.
.A
Chu, S. C.
Berman, M.
.K
numerical solution, ordinary differential equations,
initial value problems, stiff systems
.I 2568
.T
A Graph Formulation of a School Scheduling Algorithm
.W
The problem classically titled "The Examination
Schedule Problem" takes various forms in the
literature.  Most of these formulations can be presented
in the terminology of classical Network Theory.
 One such formulation is:  Given a nondirected network,
partition its nodes into a minimal number of
subsets such that no two members of the same subset
are connected by anarc.  An obvious lower limit
to this number is the size of the largest strongly connected
subgraph.  Kirchgassner proved that an upper
limit is this size plus one.  One logical extension of
the previous work is the introduction of variable
length examinations where W(I) is the number of periods
for exam I.  The object of this paper is to generalize
the definition of largest strongly connected subgraph
to include the weighting of nodes, to present an
approximate algorithm which usually finds the largest
strongly connected subgraph, and to discuss the
application of this algorithm to the solution of
school scheduling and exam scheduling problems.
.A
Salazar, A.
Oakford, R. V.
.K
scheduling, school scheduling, examination scheduling,
nondirected network, graph, subgraph, strongly
connected subgraph
.I 2569
.T
Computer Generation of Gamma Random Variates
with Non-integral Shape Parameters
.W
When the shape parameter, a, is integral,
generating gamma random variables with a digital
computer is straightforward.  There is no simple method
for generating gamma random variates with non-integral
shape parameters.  A common procedure is to approximately
generate such random variables by use of the
so-called probability switch method.  Another procedure,
which is exact, is due to Johnk.  This paper
presents a rejection method for exactly generating
gamma random variables when a is greater than 1.
The efficiency of the rejection method is shown to
be better than the efficiency of Johnk's method.
The paper concludes that when a is non-integral the following
mix of procedures yields the best combination
of accuracy and efficiency: (1) when a is less than
1, use Johnk's method; (2) when 1 is less than a
and a is less than 5, use the rejection method; (3) when
a is greater than 5, use the probability switch
method.
.A
Wallace, N. D.
.K
simulation, gamma random variables,
probability distribution, random numbers
.I 2570
.T
A Comparison of List Schedules for Parallel Processing Systems
.W
The problem of scheduling two or more processors
to minimize the execution time of a program
which consists of a set of partially ordered tasks
is studied.  Cases where task execution times are
deterministic and others in which execution times are
random variables are analyzed.  It is shown that
different algorithms suggested in the literature vary significantly
in execution time and that the B-schedule
of Coffman and Graham is near-optimal.  A dynamic programming
solution for the case in which execution
times are random variables is presented.
.A
Adam, T. L.
Chandy, K. M.
Dickson, J. R.
.K
parallel processing, precedence graphs, scheduling,
list scheduling, optimization, dynamic programming
.I 2571
.T
An Analytic Model of the Hasp Execution Task Monitor
.W
The HASP Execution Task Monitor periodically
rearranges the OS/360 dispatching chain to give
tasks preemptive execution priority in inverse order to
that of their cpu utilization history.  The effect
is to keep the I/O bound tasks active and to prevent
cpu bound tasks from locking out other tasks.  This
paper develops a simple model of the Execution Task
Monitor and employs it to study the effectiveness
of the monitor in improving system performance.  A
modified strategy monitor control is investigated
for the case of task execution in a memory hierarchy of varying speeds.
.A
Strauss, J. C.
.K
Hasp, OS/360, dispatching, scheduling, modeling, performance evaluation
.I 2572
.T
Arguments for a Moratorium on the Construction
of a Community Information Utility
.W
In this article the author urges a prudent
and decentralized approach to the question of the
design and desirability of computerized community information
utilities.  Before accepting the inevitability
and desirability of this or any technology, we should:
(1) be sure of the feasibility (internally and
externally) of what is proposed; (2) project and perhaps
wait for changes in complementary techniques;
(3) evaluate current and projected supplementary techniques;
(4) establish the existence of demand for
what is proposed; (5) take steps to involve a representative
group of ultimate users in systems design,
and (6) carefully think through possible side effects
on man and his world view.  Current proposals for
community information utilities are examined in this
framework, and the conclusion is drawn that society
is not yet in a position to justify either the construction
of an information utility in a prototype
community or the acceptance of a policy in
favor of its widespread implementation.
.A
Press, L. I.
.K
community information utilities, social implications, public policy
.I 2573
.T
Computer Programming as an Art
.A
Knuth, D. E.
.I 2574
.T
Multiple Exists from a Loop Using Neither GO TO nor Labels
.A
Evans, R. V.
.K
goto free programming, control structures,
multiple exists from loops, exit statement
.I 2575
.T
The Best-Match Problem in Document Retrieval
.A
Van Rijsbergen, C. J.
.K
document retrieval, best match, clustering, file
searching, matching, dissimilarity, hierarchy,
classification
.I 2576
.T
A Simple Technique for Representing Strings in Fortran IV
.A
Hanson, D. R.
.K
string processing, Fortran IV, string representation,structured
programming, data structures
.I 2577
.T
An On-Site Data Management System Application in Field Archaeology
.A
Brown, J. A.
Werner, B.
.K
APL-PLUS, archaeology, Koster prehistoric
site data management, retrieval systems
.I 2578
.T
Self-stabilizing Systems in Spite of Distributed Control
.A
Dijkstra, E. W.
.K
multiprocessing, networks, self-stabilization, synchronization,
mutual exclusion, robustness, sharing,
error recovery, distributed control, harmonious cooperation, self-repair
.I 2579
.T
Register Allocation Via Usage Counts
.W
This paper introduces the notion of usage counts,
shows how usage counts can be developed by
algorithms that eliminate redundant computations, and
describes how usage counts can provide the basis
for register allocation.  The paper compares register
allocation based on usage counts to other commonly
used register allocation techniques, and presents evidence
which shows that the usage count technique
is significantly better than these other techniques.
.A
Freiburghouse, R. A.
.K
optimization, redundant computations, common subexpressions,
register allocation, compilers, programming
languages, virtual memory, demand paging
.I 2580
.T
A Method for Composing Simple Traditional Music by Computer
.W
A method is described for composing musical
rounds by computer.  This method uses some music
theory plus additional heuristics.  Fundamental to the
method is a set of productions together with sets
of applicability rules and weight rules which operate
on the productions deciding when and to what extent
they are available for use.  Several rounds generated
by the computer implementation of the method are
presented.  Generally, the resultant music sounds mediocre
to the professional although usually pleasing
to the layman.  It appears that full-blown music theory
is not needed for rounds--all the hardware required
for structural levels is not necessary for these pieces.
 The author has tried to address both musicians
and computer scientists.
.A
Rader, G. M.
.K
artificial intelligence, heuristic programming,
models of cognitive processes, computer music,
computer composition, music theory, formal languages, probabilistic grammars
.I 2581
.T
A Locally-Organized Parser for Spoken Input
.W
This paper describes LPARS, a locally-organized
parsing system, designed for use in a continuous
speech recognizer.  LPARS processes a string of phonemes
which contains ambiguity and error. The system
is locally-organized in the sense that it builds local
parse structures from reliable word candidates
recognized anywhere in an input utterance.  These local
structures are used as "islands of reliability"
to guide the search for more highly garbled
words which might complete the utterance.
.A
Miller, P. L.
.K
parsing, speech recognition, speech understanding,
augmented transition network, local parsing
.I 2582
.T
Improving Locality by Critical Working Sets
.W
A new approach to program locality improvement
via restructuring is described.  The method
is particularly suited to those systems where primary memory
is managed according to a working set strategy.
 It is based on the concept of critical working set, a
working set which does not contain the next memory
reference.  The data the method operates upon are extracted from
a trace of the program to be restructured.
 It is shown that, except in some special cases, the
method is not optimum.  However, the experimental
results obtained by using the method to restructure an
interactive text editor and the file system module
of an operating system have shown its substantial superiority
over the other methods proposed in the
literature.
.A
Ferrari, D.
.K
program restructuring, program segmentation, locality
improvement, memory hierarchies, virtual
memory, multiprogramming, restructuring techniques, static
restructuring, dynamic restructuring, working
set strategy, critical working set
.I 2583
.T
Guidelines for Humanizing Computerized Information
Systems: A Report from Stanley House
.A
Sterling, T. D.
.K
humanization, social implication, management, information
systems, regulations, social and behavioral
sciences, philosophy
.I 2584
.T
Enumerating Full-Time Programmers
.W
Data from the 1970 Census and the Department
of Labor's Area Wage Surveys are used to derive
estimates of the number of full-time programmers employed
during the years 1969 through 1973.  The 1973
figure of 180,000 is considerably less than suggested in
earlier reports.  It is recommended that educational
administrators consider whether the many courses aimed
at training programmers are justified on a vocational
basis.
.A
Gilchrist, B.
Weber, R. E.
.K
programmer, employment, 1970 Census, Area Wage Survey
.I 2585
.T
Efficient Implementation of a Variable Projection
Algorithm for Nonlinear Least Squares Problems
(Errata)
.A
Krogh, F. T.
.I 2586
.T
Adapting Optimal Code Generation for Arithmetic
Expressions to the Instruction Sets Available
on Present-Day Computers (Errata)
.A
Stockhausen, P. F.
.I 2587
.T
On the Construction of a Representative Synthetic Workload (Errata)
.A
Sreenivarsan, K.
Kleinman, A. J.
.I 2588
.T
Rosenbrock Function Minimization (Algorithm R450)
.A
Klemes, J.
Klemsa, J.
.I 2589
.T
A Computer Routine for Quadratic and Linear
Programming Problems (Algorithm R431)
.A
Proll, L. G.
.I 2590
.T
Hypergeometric (Algorithm C191)
.A
Kopelaar, H.
.I 2591
.T
Numerical Inversion of Laplace Transform (Algorithm A486)
.A
Veillon, F.
.K
Laplace transform inversion
.I 2592
.T
On Generation of Test Problems for Linear Programming Codes
.W
Users of linear programming computer codes have
realized the necessity of evaluating the capacity,
effectiveness, and accuracy of the solutions provided
by such codes.  Large scale linear programming
codes at most installations are assumed to be generating correct
solutions without ever having been "bench-marked"
by test problems with known solutions.  The reason for
this failure to adequately test the codes is that
rarely are there large problems with known solutions readily
available.  This paper presents a theoretical
justification and an illustrative implementation of a method
for generating linear programming test problems
with known solutions.  The method permits the generation
of test problems that are of arbitrary size
and have a wide range of numerical characteristics.
.A
Charnes, A.
Raike, W. M.
Stutz, J. D.
Walters, A. S.
.K
linear programming, test problem generation,
LP program evaluation, LP program validation
.I 2593
.T
A Back-end Computer for Data Base Management
.W
It is proposed that the data base management
function be placed on a dedicated back-end computer
which accepts commands (in a relatively high level language
such as the CODASYL Data Base Task Group,
April 1971 Report) from a host computer, accesses the
data base on secondary storage, and returns results.
 The advantages of such a configuration are discussed.  An
experimental implementation, called the experimental
Data Management System, XDMS, is described and certain
conclusions about the back-end approach are drawn
from this implementation.
.A
Canaday, R. H.
Harrison, R. D.
Ivie, E. L.
Ryder, J. L.
Wehr, L. A.
.K
data base management, information retrieval, computer
configurations, computer networks, Data Base
Task Group Language, data base protection,
data base portability, back-end computer
.I 2594
.T
Structured Data Structures
.W
Programming systems which permit arbitrary
linked list structures enable the user to create
complicated structures without sufficient protection.
 Deletions can result in unreachable data elements,
and there is no guarantee that additions will be performed
properly.  To remedy this situation, this
paper proposes a gauge which provides for the creation
of a restricted class of data structures but ensures
the correctness of the program.  This is accomplished
by an explicit structure declaration facility,
a restriction on the permissible operations, and execution-time checks.
.A
Shneiderman, B.
Scheuermann, P.
.K
structured programming, data structures, data base management system
.I 2595
.T
A Note on the Calculation Working Set Size
.W
Finite-length reference string of arbitrary
structure are considered, and an exact expression
for average working set size in terms of "corrected"
interreference interval statistics is derived.
An example is discussed; upper and lower bounds are obtained;
and the average working set size function
is shown to be efficiently obtained for a set of page
sizes, in a single pass of the reference string.
 This work follows the developments of a paper by Denning
and Schwartz, who consider infinite-length
reference strings which satisfy certain statistical
properties and who derive an expression relating
the asymptotic average working set size to the asymptotic
missing page rate function under working set
replacement.
.A
Slutz, D. R.
Traiger, I. L.
.K
working-set model, paging, program behavior
.I 2596
.T
A Weighted Buddy Method for Dynamic Storage Allocation
.W
An extension of the buddy method, called the weighted
buddy method, for dynamic storage allocation
is presented.  The weighted buddy method allows block
sizes of 2^k and 3(2^k), whereas the original buddy
method allowed only block sizes of 2^k. This extension
is achieved at an additional cost of only two
bits per block.  Simulation results are presented which
compare this method with the buddy method.  These
results indicate that for a uniform request distribution,
the buddy system has less total memory fragmentation
than the weighted buddy algorithm.  However, the total
fragmentation is smaller for the weighted buddy
method when the requests are for exponentially distributed block sizes.
.A
Shen, K. K.
Peterson, J. L.
.K
weighted buddy algorithm, buddy systems,
memory allocation, dynamic storage allocation
.I 2597
.T
Monitors: An Operating System Structuring Concept
.W
This paper develops Brinch-Hansen's concept of
a monitor as a method of structuring an operating
system.  It introduces a form of synchronization, describes
a possible method of implementation in terms
of semaphores and gives a suitable proof rule.  Illustrative
examples include a single resource scheduler,
a bounded buffer, an alarm clock, a buffer pool, a
disk head optimizer, and a version of the problem
of readers and writers.
.A
Hoare, C. A. R.
.K
monitors, operating systems, scheduling, mutual
exclusion, synchronization, system implementation
languages, structured multiprogramming
.I 2598
.T
Extending the Information Theory Approach to Converting
Limited-Entry Decision Tables to Computer
Programs
.W
This paper modifies an earlier algorithm for
converting decision tables into flowcharts which
minimize subsequent execution time when compiled into
a computer program.  The algorithms considered
in this paper perform limited search and, accordingly,
do not necessarily result in globally optimal
solutions.  However, the greater search effort needed
to obtain a globally optimal solution for complex
decision tables is usually not justified by sufficient
savings in execution time.  There is an analogy
between the problem of converting decision tables into
efficient flowcharts and the well-understood problem
in information theory of noiseless coding.  The results
of the noiseless coding literature are used to
explore the limitations of algorithms used to solve
the decision table problem.  The analogy between
the two problems is also used to develop improvements
to the information algorithm in extending the depth
of search under certain conditions and in proposing
additional conditions to be added to the decision
table.  Finally, the information algorithm is compared
with an algorithm proposed in a recent paper by
Verhelst.
.A
Shwayder, K.
.K
coding, decision tables, flowcharting, information
theory, noiseless channel, sorting
.I 2599
.T
 First Order Approximation to the Optimum Checkpoint Interval
.A
Young, J. W.
.K
checkpoint, job failure, operations, programming
checkpoint, random failure, operations, programming
.I 2600
.T
Computation of g-Splines via a Factorization
Method [E2] (Algorithm A485)
.A
Eidson, H. D.
Schumaker, L. L.
.K
approximation, spline approximation
.I 2601
.T
Evaluation of the Modified Bessel Functions K0(Z)
and K1(Z) for Complex Arguments [S17] (Algorithm
A484)
.A
Burrell, K. H.
.K
Bessel functions, Hankel functions, modified
Bessel functions, Gauss-Hermite quadrature
.I 2602
.T
Masked Three-Dimensional Plot Program
with Rotations [J6] (Algorithm A483)
.A
Watkins, S. L.
.K
plotting, three-dimensional plotting
.I 2603
.T
The Equivalence of Reducing Transition
Languages and Deterministic Languages
.W
The class of reducing transition languages
introduced by Eickel, Paul, Bauer, and Samelson
was shown by Morris to be a proper superclass of the
simple precedence languages.  In this paper this
result is extended, showing that, in fact, the first class
is equivalent to the class of deterministic
context free languages.
.A
Schkolnick, M.
.K
reducing transition languages, syntax controlled
generators, deterministic context-free grammars
.I 2604
.T
An Interactive Graphic Display for Region
Partitioning by Linear Programming
.W
Using linear programming, an interactive graphic
display system has been implemented to solve
the region design problem of partitioning a region into
N nonoverlapping subregions in such a way that
their areas are in specified proportions and that the
total cost of servicing them is a minimum.  In
a conversational manner, a user can easily obtain different
partitionings by specifying and modifying
the boundary, the service centers' locations, the area
proportions, and the cost functions.  Examples
are included.
.A
Cheung, T.
.K
interactive graphic display, region partitioning,
area specification, linear programming
.I 2605
.T
A Precise Numerical Analysis Program
.W
A description is given of a program for computing
the solution to a small number of standard
numerical analysis problems to any specified accuracy,
up to a limit of 2000 correct decimal places.
 Each computed number is bounded in an interval with a
multiple precision midpoint.  Arithmetic operations
involving these numbers are executed according to interval
arithmetic concepts, with non-significant
digits automatically discarded.  Details are supplied
of problem specification and problem computation.
.A
Aberth, O.
.K
interval arithmetic, multiple precision, list structure, error control
.I 2606
.T
A New Integration Algorithm for Ordinary Differential
Equations Based on Continued Fraction Approximations
.W
A new integration algorithm is found, and an
implementation is compared with other programmed
algorithms.  The new algorithm is a step-by-step procedure
for solving the initial value problem in ordinary
differential equations.  It is designed to approximate
poles of small integer order in the solutions
of the differential equations by continued fractions obtained
by manipulating the sums of truncated Taylor
series expansions.  The new method is compared with
Gragg-Bulirsh-Stoer, and the Taylor series method.
 The Taylor series method and the new method are shown
to be superior in speed and accuracy, while the
new method is shown to be most superior when the solution
is required near a singularity.  The new method
can finally be seen to pass automatically through singularities
where all the other methods which are
discussed will have failed.
.A
Willers, I. M.
.K
ordinary differential equations, initial value problem,
integration, Taylor series, singularities,
continued fractions, program comparison
.I 2607
.T
A Problem-List of Issues Concerning Computers and Public Policy
.A
ACM Committee
.K
economic and sociological effects, the public and computers
.I 2608
.T
Recurrence Relations for the Fresnel Integral and Similar Integrals
.A
Acton, F. S.
.K
recurrence relations, Fresnel integral, exponential integral
.I 2609
.T
Interpolation with Rounded Ramp Functions
.W
A new interpolation function is introduced.
 It has infinitely many continuous derivatives
and is a composition of ramp functions with smoothed bends
called Rounded Ramp Functions.  How the interpolation
function can be extended to more than one variable is
shown.  An efficient Fortran program is given by
which the interpolation function can be obtained for a given point set.
.A
Lagerlof, R. O. E.
.K
interpolation, approximation, smooth interpolation,
multi variable interpolation, interpolation
function, approximation function, spline-like function
.I 2610
.T
Gauss Harmonic Interpolation Formulas
.W
Let R be an open, bounded, simply connected
region in the (x,y)-plane and let (x*,y*) be a
point in R.  Assuming R is starlike with respect to
(x*,y*), we discuss a method for computing Gauss
harmonic interpolation formulas for R and the point (x*,y*).
 Such formulas approximate a harmonic function
at (x*,y*) in terms of a linear combination of its
values at certain selected points on the boundary
of R.  Such formulas are useful for approximating
the solution of the Dirichlet problem for R.
.A
Stroud, A. H.
.K
interpolation, quadrature, harmonic interpolation,
harmonic quadrature, Dirichlet problem
.I 2611
.T
The Complex Method for Constrained Optimization (Algorithm R454)
.A
Shere, K. D.
.I 2612
.T
Rosenbrock Function Minimization (Algorithm R450)
.A
Bultheel, A.
.I 2613
.T
Transitivity Sets [G7] (Algorithm A482)
.A
McKay, J.
Regener, E.
.K
transitivity, sets
.I 2614
.T
Arrow to Precedence Network Transformation [H] (Algorithm A481)
.A
Crandall, K. C.
.K
critical path, networks, precedence networks
.I 2615
.T
Procedures for computing Smoothing and Interpolating
Natural Splines [E1] (Algorithm A480)
.A
Lyche, T.
Schumaker, L. L.
.K
approximation, interpolation, spline, natural spline, spline smoothing
.I 2616
.T
On the Conversion of Programs to Decision Tables: Method and Objectives
.W
The problems of converting programs to decision
tables are investigated.  Objectives of these
conversions are mainly program debugging and optimization
in practice.  Extensions to the theory of computation
and computability are suggested.
.A
Cavouras, J. C.
.K
decision tables, program optimization, debugging,
semantics, theory of programming, systems analysis
.I 2617
.T
A Note on Subexpression Ordering in
the Evaluation of Arithmetic Expressions
.A
Denning, P. J.
Graham, G. S.
.I 2618
.T
A New Solution of Dijkstra's Concurrent Programming Problem
.W
A simple solution to the mutual exclusion problem
is presented which allows the system to continue
to operate despite the failure of any individual component.
.A
Lamport, L.
.K
critical section, concurrent programming, multiprocessing, semaphores
.I 2619
.T
Graph Coloring Conditions for the Existence
of Solutions to the Timetable Problem
.W
A necessary and sufficient condition is presented
for the existence of a solution to the Gotlieb
class-teacher timetable problem.  Several relationships
are established between the class-teacher timetable
problem and graphs with preconditions.  These preconditions
place additional restrictions on the coloration
of a graph.  The preconditions correspond to the unavailability
constraints and preassigned meetings
in the class-teacher timetable problem.  Using some recent
results that convert graphs with preconditions
to graphs without them, it is shown that the existence
of a coloration of a graph is the required necessary
and sufficient condition.
.A
Neufeld, G. A.
Tartar, J.
.K
graphs, coloration, preassignment, prevention
of assignment, class-teacher timetables
.I 2620
.T
Execution Time Requirements for Encipherment Programs
.W
Although encipherment has often been discussed
as a means to protect computer data, its costs
are not well established.  Five experiments were conducted
to measure the cpu time on a CDC 6400 required
by additive ciphers programmed both in assembly language
and in Fortran: a "null transformation" to measure
the time to move data without encipherment; encipherment
with one-word key; encipherment with a 125-word
key; double key encipherment; and encipherment using
a pseudo random key.  The results were analyzed
for consistency over 100 runs, and the effects of constant
and intermittent errors were considered.
Timing rates for assembly language encipherment ranged
from 498,800 characters per second for a pseudo
random key cipher to 2,092,000 characters per second
for a constant one-word key cipher.  The latter
is almost equivalent to the rate required simply to move
data without encipherment.  Fortran tests required
over four times as much cpu time.  This paper introduces
the idea on enciphering time coefficient the
ratio of enciphering time to the time taken to
fetch and store data without encipherment.
.A
Friedman, T. D.
offman, L. J.
.K
encipherment, ciphers, security, privacy transformations,
protection, cryptography, cryptology
.I 2621
.T
A High Security Log-in Procedure
.W
The protection of time sharing systems from
unauthorized users is often achieved by the use
of passwords.  By using one-way ciphers to code the passwords,
the risks involved with storing the passwords
in the computer can be avoided.  We discuss the selection
of a suitable one-way cipher and suggest that
for this purpose polynomials over a prime modulus are
superior to one-way ciphers derived from Sannon
codes.
.A
Purdy, G. B.
.K
operating systems, time sharing systems, security, cryptography
.I 2622
.T
A User Authentication Scheme Not Requiring Secrecy in the Computer
.W
In many computer operating systems a user authenticates
himself by entering a secret password
known solely to himself and the system.  The system compares
this password with one recorded in a Password
Table which is available to only the authentication
program.  The integrity of the system depends on
keeping the table secret.  In this paper a password
scheme is presented which does not require secrecy
in the computer.    All aspects of the system, including
all relevant code and data bases, may be known
by anyone attempting to intrude.  The scheme is based
on using a function H which the would-be intruder
is unable to invert.  This function is applied to the
user's password and the result compared to a table
entry, a match being interpreted as authentication of
the user.  The intruder may know all about H and
have access to the table, but he can penetrate the system
only if he can invert H to determine an input
that produces a given output.  This paper discusses
issues surrounding selection of a suitable H.  Two
different plausible arguments are given that penetration
would be exceedingly difficult, and it is then
argued that more rigorous results are unlikely.  Finally,
some human engineering problems relating to
the scheme are discussed.
.A
Evans, A. Jr.
Kantrowitz, W.
Weiss, E.
.K
operating system security, security, authentication,
passwords, one-way encryption, cryptology
.I 2623
.T
A New Technique for Compression and Storage of Data
.W
The widespread tendency toward storage of
large programs and blocks off text has produced a
need for efficient methods of compressing and storing
data.  This paper describes techniques that can,
in most cases, decrease storage size by a factor of
from two to four.  The techniques involve special
handling of leading and trailing blanks, and the encoding
of other symbols in groups of fixed size as
unique fixed point numbers.  The efficiency of the
system is considered and pertinent statistics are
given and compared with statistics for other information coding techniques.
.A
Hahn, B.
.K
file maintenance, information retrieval, utility
programs, text compression, coding techniques,
data storage, data management
.I 2624
.T
Formal Requirements for Virtualizable Third Generation Architectures
.W
Virtual machine systems have been implemented
on a limited number of third generation computer
systems, e.g. CP-67 on the IBM 360/67.  From previous
empirical studies, it is known that certain third
generation computer systems, e.g. the DEC PDP-10, cannot
support a virtual machine system.  In this paper,
model of a third-generation-like computer system is
developed.  Formal techniques are used to derive
precise sufficient conditions to test whether such
an architecture can support virtual machines.
.A
Popek, G. J.
Goldberg, R. P.
.K
operating system, third generation architecture,
sensitive instruction, formal requirements, abstract
model, proof, virtual machine, virtual memory,
hypervisor, virtual machine monitor
.I 2625
.T
Capability-Based Addressing
.W
Various addressing schemes making use of segment
tables are examined.  The inadequacies of
these schemes when dealing with shared addresses are
explained. These inadequacies are traced to the
lack of an efficient absolute address for objects in
these systems.  The direct use of a capability as
an address is shown to overcome these difficulties
because it provides the needed absolute address.
Implementation of capability-based addressing is discussed.
 It is predicted that the use of tags to
identify capabilities will dominate.  A hardware address
translation scheme which never requires the
modification of the representation of capabilities is
suggested. The scheme uses a main memory hash table
for obtaining a segment's location in main memory given
its unique code.  The hash table is avoided for
recently accessed segments by means of a set of associative
registers.  A computer using capability-based
addressing may be substantially superior to present
systems on the basis of protection, simplicity of
programming conventions, and efficient implementation.
.A
Fabry, R. S.
.K
addressing, capabilities, addressing hardware,
protection, protection hardware, shared addresses,
information sharing, operating systems, computer
utility, segmentation, tagged architecture
.I 2626
.T
Protection and the Control of Information Sharing in Multics
.W
The design of mechanisms to control the sharing
of information in the Multics system is described.
 Five design principles help provide insight into the
tradeoffs among different possible designs.  The
key mechanisms described include access control lists,
hierarchical control of access specifications,
identification and authentication of users, and primary
memory protection.  The paper ends with a discussion
of several known weaknesses in the current protection mechanism design.
.A
Saltzer, J. H.
.K
Multics, protection, security, privacy, access control,
authentication, computer utilities, time-sharing
systems, proprietary programs, protected subsystems, virtual memory, descriptors
.I 2627
.T
Scheduling Independent Tasks to Reduce Mean Finishing Time
.W
Sequencing to minimize mean finishing time
(or mean time in system) is not only desirable to
the user, but it also tends to minimize at each point
in time the storage required to hold incomplete
tasks.  In this paper a deterministic model of independent
tasks is introduced and new results are derived
which extend and generalize the algorithms known for
minimizing mean finishing time.  In addition to
presenting and analyzing new algorithms it is shown
that the most general mean-finishing-time problem
for independent tasks is polynomial complete, and hence unlikely
to admit of a non-enumerative solution
.A
Bruno, J.
Coffman, E. G. Jr.
Sethi, R.
.K
minimizing mean finishing time, minimizing mean flow
time, sequencing algorithms, optimal scheduling
algorithms, deterministic scheduling models
.I 2628
.T
Minimal-Total-Processing Time Drum and Disk Scheduling Disciplines
.W
This article investigates the application of
minimal-total-processing-time (MTPT) scheduling
disciplines to rotating storage units when random arrival
of requests is allowed.  Fixed-head drum and
moving-head drum and moving-head disk storage units are
considered, and emphasis is placed on the relative
merits of the MTPT scheduling discipline with respect
to the shortest-latency-time-first (SLTF) scheduling
discipline.  The results of the simulation studies
presented show that neither scheduling discipline
is unconditionally superior to the other.  For most
fixed-head drum applications, the SLTF discipline
is preferable to MTPT, but for intra-cylinder disk scheduling
the MTPT discipline offers a distinct advantage
over the SLTF discipline.  The computational requirements
of an algorithm that implements the MTPT scheduling
discipline are shown to be comparable to SLTF algorithms.
In both cases, the sorting procedure is the
most time-consuming phase of the algorithm.
.A
Fuller, S. H.
.K
drum scheduling, disk scheduling, shortest-latency-time-first
(SLTF), minimal-total-processing-time
(MTPT), rotating storage units
.I 2629
.T
The UNIX Time-Sharing system
.W
UNIX is a general-purpose, multi-user, interactive
operating system for the Digital Equipment
Corporation PDP-11/40 and 11/45 computers.  It offers
a number of features seldom found even in larger
operating systems, including: (1) a hierarchical file system
incorporating demountable volumes; (2) compatible
file, device, and inter-process I/O; (3) the ability to
initiate asynchronous processes; (4) system command
language selectable on a per-user basis; and (5) over
100 subsystems including a dozen languages.This
paper discusses the nature and implementation of the
file system and of the user command interface.
.A
Ritchie, D. M.
Thompson, K.
.K
time-sharing, operating system, file system, command language, PDP-11
.I 2630
.T
On Computing Sets of Shortest Paths in a Graph
.W
Two algorithms are presented that construct
the k shortest paths between every pair of vertices
in a directed graph.  These algorithms generalize the Floyd
algorithm and the Dantzig algorithm for finding
the shortest path between every pair of vertices in a directed graph.
.A
Minieka, E.
.K
graph, network, shortest path, algorithm
.I 2631
.T
An Information-Theoretic Approach to
Text Searching in Direct Access Systems
.W
Using direct access computer files of bibliographic
information, an attempt is made to overcome
one of the problems often associated with information
retrieval, namely, the maintenance and use of large
dictionaries, the greater part of which is used only
infrequently.  A novel method is presented, which
maps the hyperbolic frequency distribution.  This is
more suited to implementation on storage devices.
 This method treats text as a string of characters rather
than words bounded by spaces, and chooses subsets
of strings such that their frequencies of occurrence are
more even than those of word types.  The members
of this subset are then used as index keys for retrieval.
The rectangular distribution of key frequencies
results in a much simplified file organization
and promises considerable cost advantages.
.A
Barton, I. J.
Creasey, S. E.
Lynch, M. F.
Snell, M. J.
.K
text searching, information theory, file organization,
direct access, information retrieval, character
string, bit vector
.I 2632
.T
HYDRA: The Kernel of a Multiprocessor Operating System
.W
This paper describes the design philosophy of
HYDRA-the kernel of an operating system for C.mmp,
the Carnegie-Mellon Multi-Mini-Processor.  This philosophy
is realized through the introduction of a
generalized notion of "resource", both physical and virtual,
called an "object".  Mechanisms are presented
for dealing with objects, including the creation of new
types, specification of new operations applicable
to a given type, sharing, and protection of any reference
to a given object against improper application
of any of the operations defined with respect to that
type of object.  The mechanisms provide a coherent
basis for extension of the system in two directions: the
introduction of new facilities, and the creation
of highly secure systems.
.A
Wulf, W.
Cohen, E.
Corwin, W.
Jones, A.
Levin, R.
Pierson, C.
Pollack, F.
.K
operating system, kernel, nucleus, protection, security
.I 2633
.T
Compact Representation of Contour Plots for Phone Line Transmission
.W
Methods for the compact representation of contour
plots are described and tested.  These are
intended to reduce the cost of transmitting contour plots
over phone lines.  We feel some of these methods
could be used to transmit contour plots over voice grade phone lines.
.A
Adams, J.
Gary, J.
.K
contour plotting, data transmission, remote terminal, data compaction
.I 2634
.T
An Evaluation of Statistical Software in the Social Sciences
.W
Several hundred college and university computer
installations now offer various types of statistical
packages for general use.  Among those most widely available
are OSIRIS, SPSS, BMD, DATA-TEXT, and TSAR.
 In order to provide users with a basis for selection
and use, tests were made for each of these systems,
and the results are summarized as to cost and performance.
.A
Slysz, W. D.
.K
statistical computation, statistical software,
descriptive statistics, bivariate tables, Pearson
correlation, regression, factor analysis, one-way analysis of variance
.I 2635
.T
Exact Probabilities for R X C Contingency Tables (Algorithm R434)
.A
Boulton, D. M.
.I 2636
.T
Generation of Random Correlated Normal Variables (Algorithm R425)
.A
Page, R. L.
.I 2637
.T
Hidden-Line Plotting Program (Algorithm R420)
.A
Ellis, T. M. R.
.I 2638
.T
Hidden-Line Plotting Program (Algorithm R420)
.A
Gaither, B.
.I 2639
.T
Calculation of Fourier Integrals (Algorithm R418)
.A
Piessens, R.
.I 2640
.T
Modified Havie Integration (Algorithm R400)
.A
Piessens, R.
.I 2641
.T
A Minimal Spanning Tree clustering Method [Z] (Algorithm A479)
.A
Page, R. L.
.K
clustering, pattern recognition, feature
selection, minimal spanning trees
.I 2642
.T
Solution of an Overdetermined System of Equations
in the L1 Norm [F4] (Algorithm A478)
.A
Barrodale, I.
Roberts, F. D. K.
.K
L1 approximation, L1 norm, overdetermined system
of equations, linear programming, simplex method
.I 2643
.T
The Minimization of Spatially-Multiplexed Character Sets
.W
The paper describes a technique for compacting
character sets in a digital computer while retaining
fast access to individual bits.  It considers the problem
of minimizing the storage needed to contain
such tables.  Reduction techniques are developed, and
the problem is shown to reduce to a covering problem.
.A
Gimpel, J. F.
.K
parsing, lexical analysis,scanning,
string processing, spatial multiplexing
.I 2644
.T
A Theorem-Proving Language for Experimentation
.W
Because of the large number of strategies
and inference rules presently under consideration
in automated theorem proving, there is a need for developing
a language especially oriented toward automated
theorem proving.  This paper discusses some of the features
and instructions of this language.  The use
of this language permits easy extension of automated
theorem-proving programs to include new strategies
and/or new inference rules.  Such extend ability will
permit general experimentation with the various
alternative systems.
.A
Henschen, L.
Overbeek, R.
Wos, L.
.K
theorem proving, resolution, factoring,
paramodulation, programming languages
.I 2645
.T
Two Languages for Estimating Program Efficiency
.W
Two languages enabling their users to estimate
the efficiency of computer programs are presented.
 The program whose efficiency one wishes to estimate is written
in the first language, a go-to-less programming
language which includes most of the features of Algol
60.  The second language consists of interactive
commands enabling its users to provide additional information
about the program written in the first
language and to output results estimating its efficiency.
 Processors for the two languages are also
described.  The first processor is a syntax-directed
translator which compiles a program into a symbolic
formula representing the execution time for that program.
 The sound processor is a set of procedures
for that program.  The second processor is a set of
procedures for algebraic manipulation which can be
called by the user to operate on the formula produced
by the first processor.  Examples of the usage
of the two languages are included.  The limitations of
the present system, its relation to Knuth's work
on the analysis of algorithms, and some of the directions
for further research are also discussed.
.A
CCohen, J.
Zuckerman, C.
.K
programming languages, syntax-directed translation,
symbolic manipulation, program efficiency,
analysis of algorithms
.I 2646
.T
A Model for Masking Rotational Latency by Dynamic Disk Allocation
.W
This paper presents the background and algorithms
for masking the rotational latency of a disk
or drum.  It discusses the anticipatory input and output
of blocks of data to buffer and primary memories
for a mono-programmed computer system.  A basic permutation
algorithm and several variations are given.
  Because of the anticipatory nature of the I/O scheduling,
these algorithms are restricted to classes
of programs with predictable behavior.  While the methods
are not restricted to numerical computations,
matrix and partial differential equation methods are
typical examples of their use.  It is shown that
latency may be masked using a small amount of buffer
memory.  The methods discussed are independent of
the overall size of the data base being considered.
.A
Gold, D. E.
Kuck, D. J.
.K
buffer memory, memory hierarchy, permutation algorithm,
rotational latency, staging, storage allocation
.I 2647
.T
More on Algorithms that Reveal Properties
of Floating Point Arithmetic Units
.A
Gentleman, W. M.
Marovich, S. B.
.K
floating-point arithmetic, high-level
languages, philosophy of language design
.I 2648
.T
A Design for a Number Theory Package
with an Optimized Trial Division routine
.W
A number theory package is described which uses
doubly linked list structures for storing multiprecise
integers.  The package has been coded in IBM's Basic
Assembly Language and makes heavy use of the macro
language and conditional assembly.  An optimally coded
trial division routine is also described which
can be used to determine the unique factorization of large integers.
.A
Wunderlich, M. C.
Selfridge, J. L.
.K
number theory package, trial division, multiprecise
arithmetic, factorization, doubly linked lists,
pseudoprime
.I 2649
.T
On the Distributions of Significant Digits and Roundoff Errors
.W
Generalized logarithmic law is derived for
the distribution of the first t significant digits
of a random digital integer.  This result is then used
to determine the distribution of the roundoff
errors in floating-point operations, which is a mixture
of uniform and reciprocal distributions.
.A
Tsao, N.
.K
significant digits, floating-point operations,
roundoff errors, uniform distribution, reciprocal
distribution, variance, mean valve
.I 2650
.T
Order-n Correction for Regular Languages
.W
A method is presented for calculating a string
B, belonging to a given regular language L,
which is "nearest" (in number of edit operations) to a
given input string a.  B is viewed as a reasonable
"correction" for the possibly erroneous string a, where
a was originally intended to be a string of L.
 The calculation of B by the method presented requires
time proportional to |a|, the number of characters
in a.  The method should find applications in information
retrieval, artificial intelligence, and spelling
correction systems.
.A
Wagner, R. A.
.K
error correction, regular languages, regular events,
finite state automata, compiler error recovery,
spelling correction, string best match problem, correction,
corrector, errors, nondeterministic finite-state
automata
.I 2651
.T
The Treatment of Data Types in EL1
.W
In constructing a general purpose programming
language, a key issue is providing a sufficient
set of data types and associated operations in a manner
that permits both natural problem-oriented notation
and efficient implementation.  The EL1 language contains
a number of features specifically designed to
simultaneously satisfy both requirements.  The resulting
treatment of data types includes provision for
programmer-defined data types data types and generic
routines, programmer control over type conversion,
and very flexible data type behavior, in a context that
allows efficient compiled code and compact data
representation.
.A
Wegbreit, B.
.K
data types, modes, mode unions, type conversion,
coercion, generic functions, extensible languages,
data type definition, data description language, compilation
.I 2652
.T
Reduction of Compilation Costs Through Language Contraction
.W
Programming languages tailored to particular
groups of users can often be constructed by removing
unwanted features from a general purpose language.  This
paper describes the use of simulation techniques
to predict the savings in compilation cost achievable
by such an approach.  The results suggest a function
which describes the effect of changes in the power of
a language on the compilation cost of an algorithm
expressed in that language: when features not actually
used by the algorithm are removed from the language,
the cost of compiling the algorithm decreases moderately,
but when features that are needed are removed,
the compilation cost increases sharply.
.A
Shaw, M.
.K
design of programming languages, language contraction,
compiler design, compilation cost, Algol
.I 2653
.T
Solution of the Transcendental Equation w*exp(x)=x (Algorithm R443)
.A
Einarsson, B.
.I 2654
.T
Generator of Set-Partitions to Exactly R Subsets [G7] (Algorithm A477)
.A
Ehrich, G.
.K
partitions, subset generation, permutations
.I 2655
.T
Six Subprograms for Curve Fitting Using
Splines Under Tension [E2] (Algorithm A476)
.A
Cline, A. K.
.K
interpolation, splines, contouring, curve fitting
.I 2656
.T
Scalar- and Planar- Valued Curve Fitting Using Splines Under Tension
.W
The spline under tension was introduced by
Schweikert in an attempt to imitate cubic splines
but avoid the spurious critical points they induce.
The defining equations are presented here, together
with an efficient method for determining the necessary
parameters and computing the resultant spline.
 The standard scalar-valued curve fitting problem is discussed,
as well as the fitting of open and closed
curves in the plane.  The use of these curves and the
importance of the tension in the fitting of contour
lines are mentioned as application.
.A
Cline, A. K.
.K
interpolation, splines, contouring, curve fitting
.I 2657
.T
An Improved Program-Synthesizing Algorithm and Its Correctness
.W
An improved program-synthesizing algorithm
based on the algorithm proposed by Waldinger and
Lee in 1969 is given.  In the old algorithm, the program-synthesizing
problem is translated into a theorem-proving
problem, and a program is obtained by analyzing a proof.
 For the improved algorithm, the analysis is
not necessary, and a program is obtained as soon as
the proof is completed.  This is achieved by using
a modified variable tracing mechanism invented by Green
in 1969.  The correctness of the improved algorithm
is also proved; i.e. the program thus obtained
always satisfies the specification.
.A
Lee, R. C. T.
Chang, C. L.
Waldinger, R. J.
.K
program-synthesizing algorithms, theorem proving,
consequence finding, primitive resolutions
.I 2658
.T
An Alternative Approach to Mutual Recursion
in Algol 60 Using Restricted Compilers
.A
Balfour, A.
.K
Algol 60, mutual recursion, compiler restrictions
.I 2659
.T
Some Remarks on Lookup of Structured Variables
.A
Abrahams, P. W.
.K
PL/1, symbol table, structured variables,
qualified references, compilers
.I 2660
.T
Addendum to M. L. Patrick Paper
.A
Simmons, G. C.
.K
parallelism, polynomial root finding, real zeros
.I 2661
.T
Ideal Teaching Machines-A Solution to the Pedagogic Language Problem
.A
Sterling, T. D.
Pollack, S. V.
.K
education, programming languages, simulators
.I 2662
.T
Graduate Education: The Ph.D. Glut: Response and Rebuttal
.A
Freeman, P.
Malcolm, M. A.
Payne, W. H.
.K
graduate education, Ph.D. production, accreditation
.I 2663
.T
A Study of Computer Use in a Graduate School of Business
.A
Lucas, H. C. Jr.
Montgomery, D. B.
Larreche, J. C.
.K
education, management, business schools
.I 2664
.T
Parallelism in Tape-Sorting
.W
Two methods for employing parallelism in tape-sorting
are presented.  Method A is the natural
way to use parallelism. Method B is new.  Both approximately
achieve the goal of reducing the processing
time by a divisor which is the number of processors.
.A
Even, S.
.K
tape sorting, parallelism, external sorting, queues, stacks
.I 2665
.T
Copying List Structures Using Bounded Workspace
.W
Two new algorithms are presented for list structure
copying using bounded workspace.  The first,
of primarily theoretical interest, shows that without
cell tag bits the task can be performed in time
n^2.  The second algorithm, assuming one tag bit in
each cell, delivers attractive practical speed.
Any noncyclic structure is copied in linear speed, while
cyclic structures are copied in average time
less than nlogn.  No foreknowledge of cycle absence
is necessary to achieve linear speed.  A variation
of the second algorithm solves an open problem concerning
list structure marking.  That result demonstrates
that marking can be done in average time nlogn without
the aid of supplemental tag bits or stacks.
.A
Lindstrom, G.
.K
list processing, copying, marking, space complexity
.I 2666
.T
On Lions' Counter Example for Gotlieb's Method
for the Construction of School Timetables
.W
The timetable problem is an essentially discrete
problem. Although the discrete problem may
have no feasible solution, there may exist a solution
to the equivalent continuous problem.  An example
is given, for which the nondiscrete solution can be
interpreted as a set of timetables, differing from
week to week, which together satisfy the long-term
requirements of the timetable problem.
.A
Smith, G.
Sefton, I. M.
.K
combinatorial, multi-index problem, necessary
conditions, schedule, school timetable, timetable
.I 2667
.T
Execution Characteristics of Programs in a Page-on-Demand System
.W
Data are presented which show the execution characteristics
of two types of commonly used programs
in a large-scale, time-shared computer system.  A software
monitoring facility built into the supervisor
was used for data collection during normal system operation.
 These data were analyzed, and results of
this analysis are presented for a Fortran compiler
and an interactive line file editor.  Probability
distribution functions and other data are given for
such things as CPU intervals, I/O intervals, and
the number of such intervals during execution.  Empirical
distributions are compared with simple theoretical
distributions (exponential, hyperexponential, and geometric).
 Other data show paging characteristics
of tasks as a function of the number of pages those tasks have in core.
.A
Boyse, J. W.
.K
program behavior, virtual memory, paging, demand paging,
software monitor, program execution characteristics,
compiler execution behavior, editor execution behavior
.I 2668
.T
Computation of Page Fault Probability from Program Transition Diagram
.W
An algorithm is given for calculating page fault
probability in a virtual memory system operating
under demand paging with various memory sizes and replacement
rules.  A first order Markov model of program
behavior is assumed, and a representation of the system
based on memory states, control states, and memory
substates is presented.  The algorithm is general in
the sense that the page fault probabilities can
be calculated for nonpredictive replacement rules applied
to any program represented by a one-step Markov
chain.  A detailed example is given to illustrate the
algorithm for Random and Least Recently Used (LRU)
replacement rules.
.A
Franklin, M. A.
Gupta, R. K.
.K
virtual memory, demand paging, replacement rule,
program model, program behavior, Markov model,
page fault, page fault probability
.I 2669
.T
A Simple Linear Model of Demand Paging Performance
.W
Predicting the performance of a proposed automatically
managed multilevel memory system requires
a model of the patterns by which programs refer to the
information stored in the memory.  Some recent
experimental measurements on the Multics virtual memory
suggest that, for rough approximations, a remarkably
simple program reference model will suffice.  The simple
model combines the effect of the information
reference pattern with the effect of the automatic management
algorithm to produce a single, composite
statement: the mean number of memory references between
paging exceptions increases linearly with the
size of the paging memory.  The resulting model is easy
to manipulate, and is applicable to such diverse
problems as choosing an optimum size for a paging memory,
arranging for reproducible memory usage charges,
and estimating the amount of core memory sharing.
.A
Saltzer, J. H.
.K
paging, demand paging, memory models, program models,
performance measurement, multilevel memory
systems, virtual memory, associative memory, memory usage accounting, Multics
.I 2670
.T
Efficient Implementation of a Variable Projection
Algorithm for Nonlinear Least Squares Problems
.W
Nonlinear least squares frequently arise for which
the variables to be solved for can be separated
into a linear and a nonlinear part.  A variable projection
algorithm has been developed recently which
is designed to take advantage of the structure of a problem
whose variables separate in this way.  This
paper gives a slightly more efficient and slightly more
general version of this algorithm than has appeared
earlier.
.A
Krogh, F. T.
.K
nonlinear least squares, parameter estimation, variable projection
.I 2671
.T
A Note on a Combinatorial Problem of Burnett and Coffman
.A
Stone, H. S.
.K
memories, interleaving, derangements, rencontres, combinatorial analysis
.I 2672
.T
Emotional Content Considered Dangerous
.A
Smoliar, S. W.
.K
artificial intelligence, heuristic programming, models
of cognitive processes, computer music, computer
composition, music theory
.I 2673
.T
Quadratic Search for Hash Tables of Size p^n
.A
Ackerman, A. F.
.K
hashing, quadratic search
.I 2674
.T
Scan Conversion Algorithms for a Cell Organized Raster Display
.W
Raster scan computer graphics with "real time"
character generators have previously been limited
to alphanumeric characters.  A display has been described
which extends the capabilities of this organization
to include general graphics.  Two fundamentally different
scan conversion algorithms which have been
developed to support this display are presented.  One
is most suitable to non-interactive applications
and the other to interactive applications.  The algorithms
were implemented in Fortran on the CDC 6400
computer.  Results obtained from the implementations show
that the noninteractive algorithms can significantly
reduce display file storage requirements at little cost
in execution time over that of a conventional
raster display.  The interactive algorithm can improve
response time and reduce storage requirements.
.A
Barrett, R. C.
Fordan, B. W. Jr.
.K
graphics, scan conversion, raster display, line
drawing, discrete image, dot generation, matrix
displays
.I 2675
.T
A Computer Routine for Quadratic and Linear
Programming Problems (Algorithm R431)
.A
Ravindran, A.
.I 2676
.T
Zeros of a Complex Polynomial (Algorithm R419)
.A
Withers, D. H.
.I 2677
.T
Incomplete Beta Ratio (Algorithm R179)
.A
Bosten, N. E.
Battiste, E. L.
.I 2678
.T
Visible Surface Plotting Program [J6] (Algorithm A475)
.A
Wright, T.
.K
hidden line problem, computer graphics, contour surface
.I 2679
.T
Some Performance Tests of "quicksort" and Descendants
.W
Detailed performance evaluations are presented
for six ACM algorithms: quicksort (No. 64),
Shellsort (No. 201), stringsort (No. 207), "TREESORT3"
(No. 245), quickersort (No. 271), and qsort (No.
402).  Algorithms 271 and 402 are refinements of algorithm
64, and all three are discussed in some detail.
 The evidence given here demonstrates that qsort (No.
402) requires many more comparisons than its author
claims.  Of all these algorithms, quickersort requires
the fewest comparisons to sort random arrays.
.A
Loeser, R.
.K
sorting, in-place sorting, sorting efficiency,
sorting performance tests, quicksort, quickersort,
qsort, Shellsort, stringsort, TREESORT3,utility sort
algorithm, general-purpose sort algorithm, sorting
algorithm documentation
.I 2680
.T
Optimal Space Allocation on Disk Storage Devices
.W
When the amount of space required for file storage
exceeds the amount which can be kept on-line,
decisions must be made as to which files are to be permanently
resident and which mountable.  These decisions
will affect the number of mount requests issued to the
operators.  This is often a bottleneck in a computing
facility, and reducing the number of mounts thus decreases
turnaround time.  An optimization model for
the assignment of files to disk packs, and packs to either
resident or nonresident status is presented.
 Heuristics are suggested for those cases in which
it is inefficient to compute the actual optimum.
.A
Morgan, H. L.
.K
disk analysis, disk optimization, disk files,file
systems, file scheduling, space allocation,
memory hierarchy
.I 2681
.T
Dynamic Memory Repacking
.W
A probabilistic model of a multiprogramming system
is exercised in order to determine the conditions
under which the dynamic repacking of main memory is beneficial.
 An expression is derived for the maximum
interference that a repacking process may introduce
before the original performance of the system is
degraded.  Alternative approaches to repacking are discussed,
and the operating conditions that lead
to improved system throughput through repacking are delineated.
.A
Balkovich, E.
Chiu, W.
Presser, L.
Wood, R.
.K
dynamic memory repacking, memory compaction,storage
fragmentation, multiprogramming system model,
probabilistic model, central processor productivity,
resource utilization, system throughput
.I 2682
.T
On the Construction of a Representative Synthetic Workload
.W
A general method of constructing a drive workload
representative of a real workload is described.
The real workload is characterized by its demands on the
various system resources.  These characteristics
of the real workload are obtained from the system accounting
data. The characteristics of the drive workload
are determined by matching the joint probability density
of the real workload with that of the drive
workload.  The drive workload is realized by using a
synthetic program in which the characteristics can
be varied by varying the appropriate parameters. Calibration
experiments are conducted to determine expressions
relating the synthetic program parameters with the workload
characteristics.  The general method is applied
to the case of two variables, cpu seconds and number
of I/O activities; and synthetic workload with 88
jobs is constructed to represent a month's
workload consisting of about 6000 jobs.
.A
Sreenivasan, K.
Kleinman, A. J.
.K
benchmarks, calibration, drive workload, input to
simulation, probability distribution, representative
workload, synthetic workload, workload characteristics
.I 2683
.T
The Synthesis of Loop Predicates
.W
Current methods for mechanical program verification
require a complete predicate specification
on each loop.  Because this is tedious and error prone,
producing a program with complete, correct predicates
is reasonably difficult and would be facilitated by machine
assistance.  This paper discusses techniques
for mechanically synthesizing loop predicates.  Two classes
of techniques are considered: (1) heuristic
methods which derive loop predicates from boundary conditions
and/or partially specified inductive assertions:
(2) extraction methods which use input predicates and
appropriate weak interpretations to obtain certain
classes of loop predicates by an evaluation on the weak interpretation.
.A
Wegbreit, B.
.K
program verification, loop predicates, inductive
assertions, synthesis of loop predicates, weak
interpretations, well-founded sets, property extraction, theorem proving
.I 2684
.T
Production Systems: or Can We Do Better than BNF?
.W
Since the development of BNF, the definition
of the syntax of programming languages has been
almost universally associated with context-free requirements.
 Yet numerous interesting and difficult
issues in syntax stem from the context-sensitive requirements,
notably the compatibility between the
declaration of an identifier and its uses, the correspondence
between actual and formal parameters, and
issues arising from block structure.  This paper explores
the use of a formal notation called Production
Systems in providing a readable and complete formal definition
of syntax.  As a practical illustration,
a small but significant subset of PL/I is considered.  A
more detailed presentation, as well as the application
to define abstract syntax and translations between languages,
is given in a previous paper by the author.
.A
Ledgard, H. F.
.K
syntax, translation, context-sensitive grammars,
compilers, formal definition, PL/I standards
.I 2685
.T
The Parallel Execution of DO Loops
.W
Methods are developed for the parallel execution
of different iterations of a DO loop.  Both
asynchronous multiprocessor computers and array computers
are considered.  Practical application to the
design of compilers for such computers is discussed.
.A
Lamport, L.
.K
parallel computing, multiprocessor computers,
array computers, vector computers, loops
.I 2686
.T
An Approximate Method for Generating Asymmetric Random Variables
.W
Tukey's lambda distribution is generalized
to provide an algorithm for generating values of
unimodal asymmetric random variables.  This algorithm
has the same advantages as the symmetric random
variable generator previously given by the authors, except
that the addition of another parameter complicates
the problem of finding the parameter values to fit a distribution.
.A
Ramberg, J. S.
Schmeiser,B. W.
.K
simulation, Monte Carlo, probability, statistics,
approximations, random variables, random numbers,
moments, distribution
.I 2687
.T
A Cell Organized Raster Display for Line Drawings
.W
Raster scan computer graphics displays with
"real time" character generators have previously
been limited to alphanumeric characters.  A display is
described which extends the capabilities of this
organization to include general graphics.  The feasibility
of such a display is shown by deriving the
minimum number of patterns required in the read only
memory of the character generator to synthesize
an arbitrary line.  The synthesis process does not compromise
picture quality since the resulting dot
patterns are identical with those of a conventional
raster display.  Furthermore, the time constraints
of a raster display are shown to be satisfied for
a typical design for very complex line drawings.
.A
Jordan, B. W. Jr.
Barrett, R. C.
.K
graphics, raster display, line drawing, discrete
image, dot generation, matrix displays
.I 2688
.T
Attribute Based File Organization in a Paged Memory Environment
.W
The high cost of page accessing implies a need
for more careful data organization in a paged
memory than is typical of most inverted file and similar
approaches to multi-key retrieval.  This article
analyses that cost and proposes a method called multiple
key hashing which attempts to minimize it.
Since this approach is not always preferable to inversion,
a combined method is described.  The exact
specifications of this combination for a file with given
data and traffic characteristics is formulated
as a mathematical program.  The proposed heuristic solution
to this program can often improve on a simple
inversion technique by a factor of 2 or 3.
.A
Rothnie, J. B. Jr.
Lozano, T.
.K
file organization, paging, retrieval algorithm,
inverted file, multiple key hashing
.I 2689
.T
A CRT Report Generating System
.A
Lucas, H. C. Jr.
.K
report generation, automated systems design, data processing, management
.I 2690
.T
A Numbering Systems for Combinations
.A
Knott, G. D.
.K
combinatorics, coding system, storage mapping function
.I 2691
.T
Comments on the Algorithms of Verhelst for the
Conversion of Limited-Entry Decision Tables to
Flowcharts
.A
King, P. J. H.
Johnson, R. G.
.K
decision table, flowcharting, preprocessor, optimal programs, search
.I 2692
.T
Reentrant Polygon Clipping
.W
A new family of clipping algorithms is described.
 These algorithms are able to clip polygons
against irregular convex plane-faced volumes in three
dimensions, removing the parts of the polygon which
lie outside the volume.  In two dimensions the algorithms
permit clipping against irregular convex windows.
 Polygons to be clipped are represented as an ordered
sequence of vertices without repetition of first
and last, in marked contrast to representation as a
collection of edges as was heretofore the common
procedure.  Output polygons have an identical format,
with new vertices introduced in sequence to describe
any newly-cut edge or edges.  The algorithms easily handle
the particularly difficult problem of detecting
that a new vertex may be required at a corner of the
clipping window.  The algorithms described achieve
considerable simplicity by clipping separately against
each clipping plane or window boundary.  Code
capable of clipping the polygon against a single boundary
is reentered to clip against subsequent boundaries.
 Each such reentrant stage of clipping need store only
two vertex values and may begin its processing
as soon as the first output vertex from the proceeding
stage is ready.  Because the same code is reentered
for clipping against subsequent boundaries, clipping
against very complex window shapes is practical.
 For perspective applications in three dimentions, a six-plane
truncated pyramid is chosen as the clipping
volume.  The two additional planes parallel to the projection
screen serve to limit the range of depth
preserved through the projection.  A perspective projection
method which provides for arbitrary view
angles and depth of field in spite of simple fixed clipping
planes is described.  This method is ideal
for subsequent hidden-surface computations.
.A
Sutherland, I. E.
Hodgman, G. W.
.K
computer graphics, hidden-surface, clipping
.I 2693
.T
Bivariate Interpolation and Smooth Surface Fitting
Based on Local Procedures [E2] (Algorithm
A474)
.A
Akima, H.
.K
bivariate interpolation, interpolation, partial
derivative, polynomial, smooth surface fitting
.I 2694
.T
Computation of Legendre Series Coefficients [C6] (Algorithm A473)
.A
Piessens, R.
.K
Legendre series, Chebyshev series
.I 2695
.T
Tridiagonalization by Permutations
.W
Tridiagonalizing a matrix by similarity transformations
is an important computational tool
in numerical linear algebra. Consider the class of sparse
matrices which can be tridiagonalized using
only row and corresponding column permutations.  The
advantages of using such a transformation include
the absence of round-off errors and improved computation time
when compared with standard transformations.
 A graph theoretic algorithm which examines an arbitrary
n x n matrix and determines whether or not it
can be permuted into tridiagonal form is given.  The
algorithm requires no arithmetic while the number
of comparisons, the number of assignments, and the number
of increments are linear in n.  This compares
very favorably with standard transformation methods.
 If the matrix is permutable into tridiagonal form,
the algorithm gives the explicit tridiagonal form.
 Otherwise, early rejection will occur.
.A
Gibbs, N. E.
Poole, W. G. Jr.
.K
tridiagonal matrix, permutation, algorithm,
eigenvalues, graph, bandwidth, sparse matrix
.I 2696
.T
A Method of Bivariate Interpolation and Smooth
Surface Fitting Based on Local Procedures
.W
A method is designed for interpolating values
given at points of a rectangular grid in a plane
by a smooth bivariate function z=z(x,Y).  The interpolating
function is a bicubic polynomial in each
cell of the rectangular grid.  Emphasis is an avoiding
excessive undulation between given grid points.
The proposed method is an extension of the method of
univariate interpolation developed earlier by the
author and is likewise based on local procedures.
.A
Akima, H.
.K
bivariate interpolation, interpolation, partial
derivative, polynomial, smooth surface fitting
.I 2697
.T
A Fast Method for Solving a Class of Tridiagonal Linear Systems
.W
The solution of linear systems having real, symmetric,
diagonally dominant,tridiagonal coefficient
matrices with constant diagonals is considered.  It is
proved that the diagonals of the LU decomposition
converges when floating-point precision.  It is also
proved that the computed LU decomposition converges
when floating-point arithmetic is used and that the limits
of the LU diagonals using floating point are
roughly within machine precision of the limits using
real arithmetic.  This fact is exploited to reduce
the number of floating-point operations required to
solve a linear system from 8n-7 to 5n+2k-3, where
k is much less than n, the order of the matrix.  If the
elements of the subdiagonals and superdiagonals
are 1, then only 4n+2k-3 operations are needed.  The
entire LU decomposition takes k words of storage,
and considerable savings in array subscripting are achieved.
 Upper and lower bounds on k are obtained
in terms of the ratio of the coefficient matrix diagonal
constants and parameters of the floating-point
number system.  Various generalizations of these results are discussed.
.A
Malcolm, M. A.
Palmer, J.
.K
numerical linear algebra, linear systems,
Toeplitz matrices, tridiagonal matrices
.I 2698
.T
Syntax-Directed Least-Errors Analysis for
Context-Free Languages: A Practical Approach
.W
A least-errors recognizer is developed informally
using the well-known recognizer of Earley,
along with elements of Bellman's dynamic programming.
 The analyzer takes a general class of context-free
grammars as drivers, and any finite string as input.
 Recognition consists of a least-errors count for
a corrected version of the input relative to the driver
grammar. The algorithm design emphasizes practical
aspects which help in programming it.
.A
Lyon, G.
.K
arbitrary input strings, context-free grammars,
parsing, dynamic programming, stored subanalyses,
separability, state merging, least-errors correction
.I 2699
.T
Automatic Data Structure Choice in a Language of Very High Level
.W
SETL is a set-theoretically oriented language
of very high level whose repertoire of semantic
objects includes finite sets, ordered n-tuples, and
sets of ordered n-tuples usable as mappings.  This
paper describes the structure of an optimizer for this
language.  Among other methods of interest, the
optimizer uses techniques which allow relations of inclusion
and membership to be established, the domains
and ranges of (tabulated) mappings to be estimated from
above and below, and the single-valuedness of
(tabulated) mappings to be proved.  Once facts of this
kind have been established, automatic choice of
data structures becomes possible. The methods employed
are based upon, and extend, known techniques of
data flow analysis.
.A
Schwartz, J. T.
.K
program optimization, automatic programming, high-level
languages, set-theoretic languages, data
structure choice
.I 2700
.T
Reduction: A Method of Proving Properties of Parallel Programs
.W
When proving that a parallel program has a
given property it is often convenient to assume
that a statement is indivisible, i.e. that the statement
cannot be interleaved with the rest of the program.
 Here sufficient conditions are obtained to show that
the assumption that a statement is indivisible
can be relaxed and still preserve properties such as
halting.  Thus correctness proofs of a parallel
system can often be greatly simplified.
.A
Lipton, R. J.
.K
deadlock free, reduction, interruptible, indivisible,
parallel program, semaphore, verification
method, process, computation sequence
.I 2701
.T
A Fast and Usually Linear Algorithm for Global
Flow Analysis (Abstract only--Complete paper JACM
23,1 January, 1976)
.W
A new algorithm for global flow analysis on
reducible graphs is presented. The algorithm is
shown to treat a very general class of function spaces.
 For a graph of e edges, the algorithm has a
worst case time bound of O(e log e) function operations.
 It is also shown that in programming terms,
the number of operations is proportional to e plus the
number of exits from program loops.  Consequently
a restriction to one-entry one-exit control structures
linearity.  The algorithm can be extended to yet
larger classes of function spaces and graphs by relaxing
the time bound.  Examples are given of code
improvement problems which can be solved using the algorithm.
.A
Graham, S. L.
Wegman, M.
.K
global flow analysis, data flow, code optimization,
common subexpression elimination, live-dead
analysis, information propagation, flow graph, reducibility,
go-to-less programming, depth-first search,
path compression
.I 2702
.T
On the Complexity of LR(k) Testing
.W
The problem of determining whether an arbitrary
context-free grammar is a member of some easily
parsed subclass of grammars such as the LR(k) grammars
is considered.  The time complexity of this problem
is analyzed both when k is considered to be a fixed
integer and when k is considered to be a parameter
of the test.  In the first case, it is shown that for
every k there exists an O(n(k+2)) algorithm for
testing the LR(k) property, where n is the size of the
grammar in question.  On the other hand, if both
k and the subject grammar are problem parameters, then
the complexity of the problem depends very strongly
on the representation chosen for k.  More specifically,
it is shown that this problem is NP-complete
when k is expressed in unary.  When k is expressed in
binary the problem is complete for nondeterministic
exponential time.  These results carry over to many
other parameterized classes of grammars, such as
the LL(k), strong LL(k), SLR(k), LC(k), and strong LC(k) grammars.
.A
Hunt, H. B. III
Szymanski, T. G.
Ullman, J. D.
.K
computational complexity, context-free grammars,
parsing, LR(k) grammars, NP-complete problems
.I 2703
.T
The Intrinsically Exponential Complexity of
the Circularity Problem for Attribute Grammars
.W
Attribute grammars are an extension of context-free
grammars devised by Knuth as a mechanism
for including the semantics of a context-free language
with the syntax of the language.  The circularity
problem for a grammar is to determine whether the semantics
for all possible sentences (programs) in
fact will be well defined.  It is proved that this problem
is, in general, computationally intractable.
 Specifically, it is shown that any deterministic algorithm
which solves the problem must for infinitely
many cases use an exponential amount of time.An improved
version of Knuth's circularity testing algorithm
is also given, which actually solves the problem within exponential time.
.A
Jazayeri, M.
Ogden, W. F.
Rounds, W. C.
.K
attribute grammars, circularity problem, context-free
grammars, computational complexity, exponential
time, semantics
.I 2704
.T
Exception Handling: Issues and a Proposed Notation
.W
This paper defines exception conditions, discusses
the requirements exception handling language
features must satisfy, and proposes some new language
features for dealing with exceptions in an orderly
and reliable way.  The proposed language features serve
to highlight exception handling issues by showing
how deficiencies in current approaches can be remedied.
.A
Goodenough, J. B.
.K
multilevel exit, goto statement, error conditions,
structured programming, ON conditions, programming
languages
.I 2705
.T
Programming Languages, Natural Languages, and Mathematics
.W
Some social aspects of programming are illuminated
through analogies with similar aspects of
mathematics and natural languages.  The split between
pure and applied mathematics is found similarly
in programming. The development of natural languages toward
flexion less, word-order based language types
speaks for programming language design based on general,
abstract constructs.  By analogy with incidents
of the history of artificial, auxiliary languages it
is suggested that Fortran and Cobol will remain
dominant for a long time to come.  The most promising
avenues for further work of wide influence are
seen to be high quality program literature (i.e. programs)
of general utility and studies of questions
related to program style.
.A
Naur, P.
.K
analogies related to social aspects,pure and applied
mathematics, language quality, language development,
artificial auxiliary languages, literature, style,
descriptive and prescriptive attitudes
.I 2706
.T
A Note on the Set Basis Problem Related
to the Compaction of Character Sets
.W
This note discusses the reduction of the
set basis problem to the clique cover problem.
.A
Kou, L. T.
Wong, C. K.
.K
compaction of character sets, set basis, set covering,
computational complexity, polynomial completeness,
clique cover
.I 2707
.T
Backtrack Programming Techniques
.W
The purpose of this paper is twofold.  First,
a brief exposition of the general backtrack technique
and its history is given.  Second, it is shown how the use
of macros can considerably shorten the computation
time in many cases.  In particular, this technique has allowed
the solution of two previously open combinatorial
problems, the computation of new terms in a well-known
series, and the substantial reduction in computation
time for the solution to another combinatorial problem.
.A
Bitner, J. R.
Reingold, E. M.
.K
backtrack, depth-first search, exhaustive search,
macros, combinatorial computing, non-attacking
queen's problem, difference-preserving codes, pentominoes,
tiling problems, squaring the square
.I 2708
.T
Practical Syntactic Error Recovery
.W
This paper describes a recovery scheme for syntax
errors which provides automatically-generated
high quality recovery with good diagnostic information
at relatively low cost. Previous recovery techniques
are summarized and empirical comparisons are made.  Suggestions
for further research on this topic conclude
the paper.
.A
Graham, S. L.
Rhodes, S. P.
.K
syntax errors, error recovery, error correction,
parsing, simple precedence, compilers, debugging
.I 2709
.T
A Genealogy of Control Structures
.W
The issue of program control structures has
had a history of heated controversy.  To put this
issue on a solid footing, this paper reviews numerous theoretical
results on control structures and explores
their practical implications.  The classic result of
Bohm and Jacopini on the theoretical completeness
of if-then-else and while-do is discussed. Several recent
ideas on control structures are then explored.
 These include a review of various other control structures,
results on time/space limitations, and theorems
relating the relative power of control structures under
notions of equivalence.  In conclusion, the impact
of theoretical results on the practicing programmer and
the importance of one-in, one-out control structures
as operational abstractions are discussed.  It is argued
further that there is insufficient evidence
to warrant more than if-then-else, while-do, and their variants.
.A
Ledgard, H. F.
Marcotty, M.
.K
structured programming, control structures,
goto statements, language design, PASCAL
.I 2710
.T
Specifying Queries as Relational Expressions:
The SQUARE Data Sublanguage
.W
This paper presents a data sublanguage called
SQUARE, intended for use in ad hoc, interactive
problem solving by non-computer specialists. SQUARE
is based on the relational model of data, and is
shown to be relationally complete; however, it avoids
the quantifiers and bound variables required by
languages based on the relational calculus.  Facilities
for query, insertion, deletion, and update on
tabular data bases are described.  A syntax is given,
and suggestions are made for alternative syntaxes,
including a syntax based on English key words for
users with limited mathematical background.
.A
Boyce, R. F
Chamberlin, D. D.
King, W. F. III
.K
database, data sublanguages, relations, query languages,
casual user, relational data model, tabular
data, interactive problem solving, nonprocedural
languages, relational completeness
.I 2711
.T
A Vector Space Model for Automatic Indexing
.W
In a document retrieval, or other pattern matching
environment where stored entities (documents)
are compared with each other or with incoming patterns
(search requests), it appears that the best indexing
(property) space is one where each entity lies as far away
from the others as possible; in these circumstances
the value of an indexing system may be expressible
as a function of the density of the object space;
in particular, retrieval performance may correlate inversely
with space density.  An approach based on
space density computations is used to choose an optimum
indexing vocabulary for a collection of documents.
 Typical evaluation results are shown, demonstrating
the usefulness of the model.
.A
Salton, G.
Wong, A.
Yang, C. S.
.K
automatic information retrieval, automatic
indexing, content analysis, document space
.I 2712
.T
Horner's Rule for the Evaluation of General Closed Queueing Networks
.W
The solution of separable closed queueing networks
requires the evaluation of homogeneous multinomial
expressions.  The number of terms in those expressions
grows combinatorially with the size of the network
such that a direct summation may become impractical.  An
algorithm is given which does not show a combinatorial
operation count.  The algorithm is based on a generalization
of Horner's rule for polynomials.  It is
also shown how mean queue size and throughput an be obtained
at negligible extra cost once the normalization
constant is evaluated.
.A
Reiser, M.
Kobayashi, H.
.K
Queueing networks, queueing theory Horner's rule,
evaluation of multinomial sums, load-dependent
service rate
.I 2713
.T
Remark on Stably Updating Mean and
Standard Deviation of Data (Corrigendum)
.A
Cotton, I.
.I 2714
.T
Merging with Parallel Processors
.W
Consider two linearly ordered sets A, B, |A|=m,
|B|=n, m<=n, and p, p<=m, parallel processors
working synchronously.  The paper presents an algorithm
for merging A and B with the p parallel processors,
which requires at most 2[log2 (2m+1)]+[3m/p] + [m/p][log2
(n/m)] steps.  If n = (2^B)m (B an integer),
the algorithm requires at most 2[log2 (m+1)] + [m/p](2+B)
steps.  In the case where m and n are of the
same order of magnitude, i.e. n=km with k being a constant,
the algorithm requires 2[log2 (m+1)] + [m/p](3+k)
steps.  These performances compare very favorably with
the previous best parallel merging algorithm,
Batcher's algorithm, which requires n/p + ((m+n)/2p)log2 m
steps in the general case and km/p + ((k+1)/2)(m/p)log2
m in the special case where n=km.
.A
Gavril, F.
.K
parallel processing, parallel merging, parallel binary insertion
.I 2715
.T
Implementation of a Structured English Query Language
.W
The relational model of data, the XRM Relational
Memory System, and the SEQUEL language have
been covered in previous papers and are reviewed.
SEQUEL is a relational data sublanguages intended
for the ad hoc interactive problem solving by non-computer
specialists.  A version of SEQUEL that has
been implemented in a prototype interpreter is described.
 The interpreter is designed to minimize the
data accessing operations required to respond to an arbitrary
query.  The optimization algorithms designed
for this purpose are described.
.A
Astrahan, M. M.
Chamberlin,D. D.
.K
relational model, query language, nonprocedural language,
database, data structure, data organization
.I 2716
.T
Optimizing the Performance of a Relational Algebra Database Interface
.W
An approach for implementing a "smart" interface
to support a relational view of data is proposed.
 The basic idea is to employ automatic programming techniques
so that the interface analyzes and efficiently
refines the high level query specification supplied by
the user.  A relational algebra interface, called
SQUIRAL, which was designed using this approach, is described
in detail. SQUIRAL seeks to minimize query
response time and space utilization by: (1) performing
global query optimization, (2) exploiting disjoint
and pipelined concurrency, (3) coordinating sort orders
in temporary relations, (4) employing directory
analysis, and (5) maintaining locality in page references.
 Algorithms for implementing the operators
of E. F. Codd's relational algebra are presented, and
a methodology for composing them to optimize the
performance of a particular user query is described.
.A
Smith, J. M.
Yen-Tang Chang, P.
.K
relational database, database optimization, inverted
file, automatic programming, query language,
data manipulation language, very high level language
.I 2717
.T
CONVERT: A High Level Translation
Definition Language for Data Conversion
.W
This paper describes a high level and nonprocedural
translation definition language, CONVERT,
which provides very powerful and highly flexible data
restructuring capabilities. Its design is based
on the simple underlying concept of a form which enables
the users to visualize the translation processes,
and thus makes data translation a much simpler task.
"CONVERT" has been chosen for conveying the purpose
of the language and should not be confused with any
other language or program bearing the same name.
.A
Shu, N. C.
Housel, B. C.
Lum, V. Y.
.K
data conversion, data restructuring, data translation,
database reorganization, translation definition,
utility program, programming languages, nonprocedural languages
.I 2718
.T
A Preliminary System for the Design of DBTG Data Structures
.W
The functional approach to database design is
introduced.  In this approach the goal of design
is to derive a data structure which is capable of supporting
a set of anticipated queries rather than
a structure which "models the business" in some other
way. An operational computer program is described
which utilizers the functional approach to design data
structures conforming to the Data Base Task Group
specifications.  The automatic programming technology
utilized by this program, although typically used
to generate procedure, is here used to generate declaratives.
.A
Gerritsen, R.
.K
network model of databases, Data Base Task Group, database
design, data structure, automatic programming,
translation, nonprocedural languages
.I 2719
.T
Mechanical Program Analysis
.W
One means of analyzing program performance
is by deriving closed-form expressions for their
execution behavior.  This paper discusses the mechanization
of such analysis, and describes a system,
Metric, which is able to analyze simple Lisp programs
and produce, for example, closed-form expressions
for their running time expressed in terms of size of input.
 This paper presents the reasons for mechanizing
program analysis, describes the operation of Metric, explains
its implementation, and discusses its limitations.
.A
Wegbreit, B.
.K
analysis of programs, performance analysis, execution
time, execution behavior, difference equations,
generating functions, list processing, Lisp, algebraic
manipulation, programming languages, analysis
of algorithms
.I 2720
.T
Optimal Balancing of I/O Requests to Disks
.W
Determining a policy for efficient allocation
and utilization of a set of disk drives with
differing operational characteristics is examined using
analytical techniques.  Using standard queueing
theory, each disk drive is characterized by a queueing
model with service time of a disk drive represented
by the probability density function of the sum of two
uniform distributions. Total response time of the
set of disk models is then minimized under varying
load conditions. The results indicate that faster
devices should have higher utilization factors and that
the number of different device types utilized
tends to decrease with decreasing load.  Specific examples
using 2314 and 3330 combinations are examined.
.A
Piepmeier, W. F.
.K
disk drive hierarchies, system evaluation, input/output,
modeling, queueing theory, balancing,
scheduling, device assignment
.I 2721
.T
The Digital Simulation of River Plankton Population Dynamics
.W
This paper deals with the development of a
mathematical model for and the digital simulation
in Fortran IV of phytoplankton and zooplankton population
densities in a river using previously developed
rate expressions.  In order to study the relationships
between the ecological mechanisms involved, the
simulation parameters were varied illustrating the
response of the ecosystem to different conditions,
including those corresponding to certain types of chemical
and thermal pollution.  As an investigation
of the accuracy of the simulation methods, a simulation
of the actual population dynamics of Asterionella
in the Columbia River was made based on approximations
of conditions in that river. Although not totally
accurate, the simulation was found to predict the general
annual pattern of plankton growth fairly well
and, specifically, revealed the importance of the annual
velocity cycle in determining such patterns.
 In addition, the study demonstrates the usefulness of
digital simulations in the examinations of certain
aquatic ecosystems, as well as in environmental
planning involving such examinations.
.A
Claudson, R. M.
.K
digital simulation, mathematical modeling, plankton
population dynamics, phytoplankton, zooplankton,
river ecosystems, ecological mechanisms, environmental simulation,
modeling ecosystems, pollution, environmental
impact, environmental planning
.I 2722
.T
Multidimensional Binary Search Trees Used for Associative Searching
.W
This paper develops the multidimensional binary
search tree (or k-d tree, where k is the dimensionality
of the search space) as a data structure for storage of
information to be retrieved by associative searches.
The k-d tree is defined and examples are given. It
is shown to be quite in its storage requirements.
 A significant advantage of this structure is that a single
data structure can handle many types of queries
very efficiently.  Various utility algorithms are developed;
their proven average running times in an
n record file are: insertion, O (log n); deletion of
the root, O (n^(k-1)/k); deletion of a random node,
O (log n); and optimization (guarantees logarithmic performance
of searches), O (n log n).  Search algorithms
are given for partial match queries with t keys specified
[proven maximum running time of O (n^(k-t)/k)]
and for nearest neighbor queries [empirically observed average
running time of O (log n).]  These performances
far surpass the best currently known algorithms for
these tasks.  An algorithm is presented to handle
any general intersection query. The main focus of this
paper theoretical.  It is felt, however, that
k-d trees could be quite useful in many applications,
and examples of potential uses are given.
.A
Bently, J. L.
.K
associative retrieval, binary search trees, key,
attribute, information retrieval system, nearest
neighbor queries, partial match queries, intersection
queries, binary tree insertion
.I 2723
.T
Multiprocessing Compactifying Garbage Collection
.W
Algorithms for a multiprocessing compactifying
garbage collector are presented and discussed.
 The simple case of two processors, one performing LISP-like
list operations and the other performing
garbage collection continuously, is thoroughly examined.
The necessary capabilities of each processor
are defined, as well as interprocessor communication
and interlocks. Complete procedures for garbage
collection and for standard list processing primitives
are presented and thoroughly explained.  Particular
attention is given to the problems of marking and relocating
list cells while another processor may be
operating on them.  The primary aim throughout is to
allow the list processor to run unimpeded while
the other processor reclaims list storage.  The more
complex cases involving several list processors
and one or more garbage collection processors are also briefly discussed.
.A
Steele, G. L. Jr.
.K
garbage collection, storage reclamation, reclaimer,
storage allocation, multiprocessing, synchronization,
semaphores, parallel processing, compactification, relocation,
LISP, list processing, free storage, pointers,
data structures, gc processor
.I 2724
.T
The Lemniscate Constants (Corrigendum)
.A
Todd, J.
.I 2725
.T
A Comparison of Simulation Event List Algorithms (Corrigendum)
.A
Vaucher, J. C.
Duval, P.
.I 2726
.T
Combining Decision Rules in a Decision Table
.W
The techniques for minimizing logic circuits
are applied to the simplification of decision
tables by the combining of decision rules. This method
is logically equivalent to the Quien-McCluskey
method for finding prime implicants.  If some of the
decision rules implied in the ELSE Rule occur with
low frequency, then the ELSE Rule can be used to further
simplify the decision table.  Several objectives
merit consideration in optimizing a decision table:(1)
reducing machine execution time; (2) reducing
preprocessing time; (3) reducing required machine memory;
(4) reducing the number of decision rules.
 (This often improves the clarity of the decision table
to a human reader.)  It will be shown that objectives
(3) and (4) can be furthered with the above methods.
 Objective (1) is also attained if overspecified
decision rules are not combined.  Objective (2) must be
compared against the potential benefits of objectives
(1), (3), and (4) in deciding whether to use the above methods.
.A
Shwayder, K.
.K
the Quine-McCluskey method, prime implicants, minimization,
maximization, logic circuit, boolean
method, coding, decision tables, flowcharting, sorting
.I 2727
.T
Multiple Byte Processing with Full-Word Instructions
.W
A method is described which allows parallel
processing of packed data items using only ordinary
full-word computer instructions, even though the processing
requires operations whose execution is contingent
upon the value of a datum.  It provides a useful technique
for processing small data items such as alphanumeric
characters.
.A
Lamport, L.
.K
byte processing, character processing, packed data
.I 2728
.T
Consecutive Storage of Relevant Records with Redundancy
.W
This paper studies the properties of a new
class of file organizations (CRWR) where records
relevant to every query are stored in consecutive storage
locations but the organizations contain redundancy.
Some theorems which provide tools for reducing redundancy
in CRWR organizations have been also developed.
Redundancies obtained by the application of these theorems
are compared with that of query-inverted file
organizations.  Some CRWR organization with minimum redundancy
have also been developed for queries which
specify sets of keys.
.A
Ghosh, S. P.
.K
consecutive, retrieval, storage, file, records, query, redundancy, key
.I 2729
.T
Comments on a Paper by T. C. Chen and I. T. Ho
.A
Smith, A. J.
.K
binary coded decimal digits, decimal data storage,
data compression, Huffman codes, variable length
codes
.I 2730
.T
Interactive Consulting via Natural Language
.W
Interactive programming systems often contain
help commands to give the programmer on-line
instruction regarding the use of the various systems
commands.  It is argued that it would be relatively
easy to make these help commands significantly more
helpful by having them accept requests in natural
language.  As a demonstration, Weizenbaum's ELIZA program
has been provided with a script that turns
it into a natural language system consultant.
.A
Sharo, S. C.
Kwasny, S. C.
.K
interactive programming, time-sharing systems, natural
language processing, computer assisted instruction
.I 2731
.T
Remark on Stably Updating Mean and Standard Deviation of Data
.A
Cotton, I. W.
.K
mean, standard deviation
.I 2732
.T
Guarded Commands, Nondeterminacy and Formal Derivation of Programs
.W
So-called "guarded commands" are introduced
as a building block for alternative and repetitive
constructs that allow nondeterministic program components
for which at least the activity evoked, but
possible even the final state, is not necessarily uniquely
determined by the initial state.  For the
formal derivation of programs expressed in terms
of these constructs, a calculus will be shown.
.A
Dijkstra, E. W.
.K
programming languages, sequencing primitives, program
semantics, programming language semantics,
nondeterminacy, case-construction, repetition, termination,
correctness proof, derivation of programs,
programming methodology
.I 2733
.T
Deterministic Parsing of Ambiguous Grammars
.W
Methods of describing the syntax of programming
languages in ways that are more flexible and
natural than conventional BNF descriptions are considered.
 These methods involve the use of ambiguous
context-free grammars together with rules to resolve
syntactic ambiguities.  It is shown how efficient
LR and LL parsers can be constructed directly from
certain classes of these specifications.
.A
Aho, A. V.
Johnson, S. C.
Ullman, J. D.
.K
programming language specification, parser generation,
translator writing systems, syntax analysis,
LR parsing, LL parsing, ambiguous grammars
.I 2734
.T
On the External Storage Fragmentation Produced
by First-Fit and Best-Fit Allocation Strategies
.W
Published comparisons of the external fragmentation
produced by first-fit and best-fit memory
allocation have not been consistent.  Through simulation,
a series of experiments were performed in order
to obtain better data on the relative performance of
first-fit and best-fit and a better understanding
of the reasons underlying observed differences. The
time-memory-product efficiencies of first-fit and
best-fit were generally within 1 to 3 percent of each
other.  Except for small populations, the size
of the request population had little effect on allocation
efficiency.  For exponential and hyperexponential
distributions of requests, first-fit outperformed best-fit;
but for normal and uniform distributions,
and for exponential distributions distorted in various
ways, best-fit outperformed first-fit.  It is
hypothesized that when first-fit outperforms best-fit,
it does so because first-fit, by preferentially
allocating toward one end of memory, encourages large blocks
to grow at the other end.  Sufficient contiguous
space is thereby more likely to be available for relatively
large requests.  Results of simulation experiments
supported this hypothesis and showed that the relative
performance of first-fit and best-fit depends
on the frequency of request.  When the coefficient of
variation of the request distribution is greater
than or approximately equal to unity, first-fit outperformed best-fit.
.A
Shore, J. E.
.K
storage fragmentation, dynamic memory allocation, first-fit, best-fit
.I 2735
.T
Discrimination in the Employment of Women in the Computer Industry
.A
Weber, R. E.
Gilchrist, B.
.K
discrimination against women, salaries, employment,
programmers, systems analysis, keypunch operators,
machine operators
.I 2736
.T
A Note on Hash Linking
.A
Bobrow, D. G.
.K
hash search, address space extension,
implicit pointers, monitor conditions
.I 2737
.T
Determining the Minimum-Area Encasing
Rectangle for an Arbitrary Closed Curve
.W
This paper describes a method for finding the
rectangle of minimum area in which a given arbitrary
plane curve can be contained.  The method is of interest
in certain packing and optimum layout problems.
 It consists of first determining the minimal-perimeter
convex polygon that encloses the given curve
and then selecting the rectangle of minimum area capable
of containing this polygon.  Three theorems
are introduced to show that one side of the minimum-area
rectangle must be colinear with an edge of the
enclosed polygon and that the minimum-area encasing rectangle
for the convex polygon is also the minimum-area
rectangle for the curve.
.A
Freeman, H.
Shapira, R.
.K
enclosed curve, optimum layout, optimum
packing, minimum-area encasing rectangle
.I 2738
.T
Use of the Concept of Transparency in the
Design of Hierarchically Structured Systems
.W
This paper deals with the design of hierarchically
structured programming systems.  It develops
a method for evaluating the cost of requiring programmers
to work with an abstraction of a real machine.
 A number of examples from hardware and software
are given as illustrations of the method.
.A
Parnas, D. L.
Siewiorek, D. P.
.K
hierarchical systems, bottom up design, levels
of abstraction, synchronization primitives
.I 2739
.T
The Restriction Language for Computer Grammars of Natural Language
.W
Over the past few years, a number of systems
for the computer analysis of natural language
sentences have been based on augmented context-free
grammars: a context-free grammar which defines a
set of parse trees for a sentence, plus a group of restrictions
to which a tree must conform in order
to be a valid sentence analysis.  As the coverage of the
grammar is increased, an efficient representation
becomes essential for further development.  This paper
presents a programming language designed specifically
for the compact and perspicuous statement of restrictions
of a natural language grammar.  It is based
on ten years' experience parsing text sentences with
the comprehensive English grammar of the N.Y.U.
Linguistic String Project, and embodies in its syntax
and routines the relations which were found to
be useful and adequate for computerized natural language
analysis.  The language is used in the current
implementation of the Linguistic String Parser.
.A
Sager, N.
Grishman, R.
.K
natural language, parsing, grammar, programming languages
.I 2740
.T
A Large Semaphore Based Operating System
.W
The paper describes the internal structure of
a large operating system as a set of cooperating
sequential processes.  The processes synchronize by
means of semaphores and extended semaphores (queue
semaphores).  The number of parallel processes is carefully
justified, and the various semaphore constructions
are explained.  The system is proved to be free of "deadly
embrace" (deadlock).  The design principle
is an alternative to Dijkstra's hierarchical structuring
of operating systems.  The project management
and the performance are discussed, too.  The operating
system is the first large one using the RC 4000
multiprogramming system.
.A
Lauesen, S.
.K
cooperating processes, operating system, semaphores,
semaphore applications, queue semaphores,
deadlock, deadly embrace, hierarchical structuring, multiprogramming,
operating system structure, asynchronous
structuring, buffering, parallel processes, synchronizing
primitives, reentrant code, RC 4000, project
management, time schedule, debugging, project planning,
project scheduling, reliability, program proving,
coroutines, correctness, program maintenance, software paging
.I 2741
.T
Decomposability, Instabilities, and
Saturation in Multiprogramming Systems
.W
A step-by-step approach to model the dynamic
behavior and evaluate the performance of computing
systems is proposed.  It is based on a technique of variable
aggregation and the concept of nearly decomposable
system, both borrowed from Econometrics.  This approach
is taken in order to identify in multiprogramming
paging systems (i) unstable regimes of operations and (ii)
critical computing loads which bring the system
into states of saturation.  This analysis leads to a
more complete definition of the circumstances in
which "thrashing" can set in.
.A
Courtois, P. J.
.K
multiprogramming, paging, performance evaluation,
saturation, instabilities, thrashing, aggregation,
system levels, hierarchy,networks of queues
.I 2742
.T
Improved Event-Scanning Mechanisms for Discrete Event Simulation
.W
Simulation models of large, complex "real-world"
applications have occasionally earned the
reputation of eating up hours of computer time.  This
problem may be attributed in part to difficulties
such as slow stochastic convergence.  However, an additional
problem lies in the fact that a significant
amount of bookkeeping time is required to keep future events
in their proper sequence.  This paper presents
a method for significantly reducing the time spent scanning
future event lists in discrete event simulations.
 There models are presented, all of which improve in effectiveness
as the events-list scan problem becomes
more burdensome.
.A
Wyman, F. P.
.K
discrete event simulation, simulation, event scanning mechanisms
.I 2743
.T
Sorting X + Y
.A
Harper, L. H.
Payne, T. H.
Savage, J. E.
Straus, E.
.K
merge sorting, computational complexity, data
modeling, computing models, binary comparisons
.I 2744
.T
Addition in an Arbitrary Base Without Radix Conversion
.W
This paper presents a generalization of an
old programming technique; using it,one may add
and subtract numbers represented in any radix, including
a mixed radix, and stored one digit per byte
in bytes of sufficient size.  Radix conversion is unnecessary,
no looping is required, and numbers may
even be stored in a display (I/O) format.  Applications
to Cobol, MIX, and hexadecimal sums are discussed.
.A
Soule, S.
.K
addition, subtraction, decimal arithmetic, arbitrary
radix arithmetic, radix conversion, MIX arithmetic,
Cobol display arithmetic, mixed radix arithmetic
.I 2745
.T
A Linear Space Algorithm for Computing Maximal Common Subsequences
.W
The problem of finding a longest common subsequence
of two strings has been solved in quadratic
time and space.  An algorithm is presented which will
solve this problem in quadratic time and in linear
space.
.A
Hirschberg, D. S.
.K
subsequence, longest common subsequence, string correction, editing
.I 2746
.T
Efficient String Matching: An Aid to Bibliographic Search
.W
This paper describes a simple, efficient algorithm
to locate all occurrences of any of a finite
number of keywords in a string of text.  The algorithm
consists of constructing a finite state pattern
matching machine from the keywords and then using the
pattern matching machine to process the text string
in a single pass.  Construction of the pattern matching
machine takes time proportional to the sum of
the lengths of the keywords.  The number of state transitions
made by the pattern matching machine in
processing the text string is independent of the number
of keywords.  The algorithm has been used to
improve the speed of a library bibliographic
search program by a factor of 5 to 10.
.A
Aho, A. V.
Corasick, M. J.
.K
keywords and phrases, string pattern matching, bibliographic
search, information retrieval, text-editing,
finite state machines, computational complexity.
.I 2747
.T
A Simplified Recombination Scheme for the Fibonacci Buddy System
.W
A simplified recombination scheme for the Fibonacci
buddy system which requires neither tables
nor repetitive calculations and uses only two
additional bits per buffer is presented.
.A
Cranston, B.
Thomas, R.
.K
Fibonacci buddy system, dynamic storage allocation, buddy system
.I 2748
.T
Indirect Threaded Code
.W
An efficient arrangement for interpretive code
is described.  It is related to Bell's notion
of threaded code but requires less space and is more
amenable to machine independent implementations.
.A
Dewar, R. B. K.
.K
threaded code, SNOBOL4, interpretors, code generation
.I 2749
.T
Significant Event Simulation
.W
This paper compares a new method of simulation
organization, called the significant event method,
with an old one, called the clock pulse method, using
as examples two automobile traffic models.  The
significant event method is found to be more efficient
than the clock pulse method at low levels of system
interaction and less efficient at high levels.  A simple
mathematical model for the trade-off in the
relative running time of the two methods is developed.
The model aids in choosing between the two simulation
methods for a particular experiment.  It is concluded
that the significant event method can be of value
in the simulation of some systems when computational
efficiency is of sufficient importance.
.A
Babich, A. F.
Grason, J.
Parnas, D. L.
.K
simulation organization, event simulation, clock
pulse simulation, significant event simulation.
.I 2750
.T
A Cost Oriented Algorithm for Data Set Allocation in Storage Hierarchies
.W
Data set allocation in today's multilevel
storage systems is usually based on qualitative,
ad hoc decisions.  While it would be desirable to obtain
an optimal solution to this allocation problem,
it is clear that the number of parameters involved makes
it intractable to straight-forward solution.
 In such a situation, we must find a set of assumptions
which simplify the problem greatly, but which
still provide a basis for considering all significant
cost elements. This paper presents such a first,
quantitative allocation step.  It considers many of the
significant detailed costs of system utilization,
data storage, data staging, and data migration.  Although
many avenues of further improvement are available,
the present algorithm seems to be usefully accurate.
As such, it can aid in quantifying the problems
of data set allocation, storage system configuration, and new device designs.
.A
Lum, V. Y.
Senko, M. E
Wang, C. P.
Ling, H.
.K
data set allocation, hierarchical storage, storage
system configuration, data staging, data migration,
storage allocation analysis
.I 2751
.T
Illumination for Computer Generated Pictures
.W
The quality of computer generated images of
three-dimensional scenes depends on the shading
technique used to paint the objects on the cathode-ray
tube screen.  The shading algorithm itself depends
in part on the method for modeling the object, which
also determines the hidden surface algorithm.  The
various methods of object modeling, shading, and hidden
surface removal are thus strongly interconnected.
 Several shading techniques corresponding to different
methods of object modeling and the related hidden
surface algorithms are presented here.  Human visual
perception and the fundamental laws of optics are
considered in the development of a shading rule that
provides better quality and increased realism in
generated images.
.A
Phong, B. T.
.K
computer graphics, graphic display, hidden surface removal.
.I 2752
.T
Generation of All the Cycles of a Graph from
a Set of Basic Cycles [H] (Algorithm 492)
.A
Gibbs, N. E.
.K
basic cycle, cycle, graph
.I 2753
.T
A Heuristic Problem Solving Design System
for Equipment or Furniture Layouts
.W
The Designer Problem Solver (DPS) demonstrates
that the computer can perform simple design
tasks.  In particular, it designs furniture and equipment
layouts.  This task was chosen because it is
simple, well defined, and characteristic of many design
tasks in architecture, engineering, urban planning,
and natural resource management.  These space planning
tasks usually involve manipulating two-dimensional
representations of objects to create feasible or optimal
solutions for problems involving topological
and metric spatial constraints.  The paper describes
extensive tests performed on the program.  DPS is
a heuristic problem solver with a planning phase prefixed
to it.  It uses the planning process to give
it a sense of direction, diagnostic procedures to locate
difficulties, and remedial actions to recover
from difficulties.  It uses a convex polygon representation
to accurately describe the objects and the
layout.  This representation allows topological and
metric constraints to be tested and the design to
be easily updated.  DPS has been applied to 50 problems.
 While it is slow and limited in scope, the
ideas behind it are general.  It demonstrates the need
for selectivity in controlling search and the
methods used to achieve it: task-specific information,
planning, diagnostic procedures, remedial actions,
and selective alternative generators.
.A
Pfefferkorn, C. E.
.K
artificial intelligence, computer-aided design,
design synthesis, diagnostic search, heuristics,
planning, problem solving, representations, search strategies,
space planning, spatial representations
.I 2754
.T
A Syntactic Algorithm for Peak Detection
in Waveforms with Applications to Cardiography
.W
Peaks in a digitized waveform are detected by an
algorithm incorporating piecewise linear approximation
and tabular parsing techniques.  Several parameters serve
to identify the waveform context enabling accurate
measurement of peak amplitude, duration, and shape.  The
algorithm is of sufficient speed to allow on-line
real-time processing.  An example of its application
is demonstrated on an electrocardiogram.
.A
Horowitz, S. L.
.K
peak detection, digitized waveform, piecewise linear
approximation, context-free grammar, bottom-up
parsing, electrocardiogram.
.I 2755
.T
The New Math of Computer Programming (Corrigendum)
.A
Mills, H. D.
.I 2756
.T
A Problem-List of Public Policy Issues
Concerning Computers and Health Care
.A
Wasserman, A. I.
.K
economic and social implications, the public
and computing, medicine and health care
.I 2757
.T
More on kth Shortest Paths
.A
Fox, B.L.
.K
networks, kth shortest paths
.I 2758
.T
A Note on the LU Factorization of a Symmetric Matrix
.A
Evans, D. J.
Hatzopoulos, M.
.K
symmetric matrices, factorization, test matrices,
matrix inversion, separable systems
.I 2759
.T
Solution of an Overdetermined System of
Equations in the L1 Norm (Algorithm R478)
.A
Fritsch, F. N.
Hindmarsh, A. C.
.I 2760
.T
Visible Surface Plotting Program (Algorithm R475)
.A
Doran, C. J.
.I 2761
.T
Visible Surface Plotting Program (Algorithm R475)
.A
Mashburn, R. G.
.I 2762
.T
Ten Subroutines for the Manipulation
of Chebyshev Series (Algorithm R446, C446)
.A
Piessens, R.
Mertens, I.
.I 2763
.T
Basic Cycle Generation [H] (Algorithm 491)
.A
Gibbs, N. E.
.K
Graph, basic cycles,fundamental cycle,
spanning tree, vertex adjacency matrix
.I 2764
.T
An Intelligent Analyzer and Understander of English
.W
The paper describes a working analysis and generation
program for natural language, which handles
paragraph length input.  Its core is a system of preferential
choice between deep semantic patterns,
based on what we call "semantic density."  The system
is contrasted: (1) with syntax oriented linguistic
approaches, and (2) with theorem proving
approaches to the understanding problem.
.A
Wilks, Y.
.K
artificial intelligence, computational linguistics,
template, paraplate, stereotype, machine translation,
understanding, natural language processing,
semantic preference, semantic density
.I 2765
.T
Analysis and performance of Inverted Data Base Structures
.W
The need to envision and architecture data base
systems in a hierarchical level by level framework
is stressed. The inverted data base (file) organization
is then analyzed, considering implementation
oriented aspects.  The inverted directory is viewed realistically
as another large data base which itself
is subjected to inversion.  Formulations are derived
to estimate average access time (read only) and
storage requirements, formalizing the interaction of data
base content characteristics, logical complexity
of queries, and machine timing and blocking specifications
identified as having a first-order effect
on performance.  The formulations presented are necessary
to be used in conjunction with any index selection
criteria to determine the optimum set of index keys.
.A
Cardenas, A. F.
.K
data base architecture, inverted file organization,
data base performance and measurement, secondary
index organization, information storage and retrieval, query answering
.I 2766
.T
Copying Cyclic List Structures in Linear Time Using Bounded Workspace
.W
A bounded workspace copying algorithm for arbitrary
list structures is given.  This algorithm
operates in linear time and does not require tag bits.
The best previous bounded workspace copying algorithms
achieved n^2 time without tag bits and n log n time with
one tag.  The only restriction on the algorithm
given here is that the copy must be placed into a contiguous
section of memory.  The method is applicable
to fixed or variable size nodes.
.A
Fisher, D. A.
.K
list processing, copying, linear time, space complexity
.I 2767
.T
A Comparison of Simulation Event List Algorithms
.W
Four algorithms are considered which can be used
to schedule events in a general purpose discrete
simulation system.  Two of the algorithms are new, one
is based on an end-order tree structure for event
notices, and another uses an indexed linear list. The algorithms
are tested with a set of typical stochastic
scheduling distributions especially chosen to show
the advantages and limitations of the algorithms.
 The end-order tree algorithm is shown to be an advantageous,
immediate replacement for the algorithm
in use with current simulation languages.  The most
promising algorithm uses the indexed list concept.
 It will require an adaptive routine before it can
be employed in general purpose simulators,but its
performance is such that further study would be fruitful.
.A
Vaucher, J. G.
Duval, P.
.K
simulation, time flow mechanisms, event list algorithm,
simulation, time flow mechanisms, event
list algorithm, simulation executive, event scheduling
routine, discrete system simulation, sorting
.I 2768
.T
An Algorithm for Locating Adjacent Storage Blocks in the Buddy System
.W
A simple scheme for the determination of the
location of a block of storage relative to other
blocks is described.  This scheme is applicable
to the buddy type storage allocation systems.
.A
Hinds, J. A.
.K
dynamic storage allocation, buddy system, generalized Fibonacci sequences
.I 2769
.T
A Modification of Warshall's Algorithm for
the Transitive Closure of Binary Relations
.W
An algorithm is given for computing the transitive
closure of a binary relation that is represented
by a Boolean matrix. The algorithm is similar to Warshall's
although it executes faster for sparse matrices
on most computers, particularly in a paging environment.
.A
Warren, H. S. Jr.
.K
Warshall's algorithm, transitive closure, reachability
matrix, directed graph, digraph, Boolean
matrix, binary relation
.I 2770
.T
The Quadratic Hash Method When the Table Size Is Not a Prime Number
.W
Previous work on quadratic hash methods is
limited mainly to the case where the table size
is a prime number.  Here, certain results are derived for
composite numbers.  It is shown that all composite
numbers containing at least the square of one of the component
primes have full-period integer-coefficient
quadratic hash functions.
.A
Batagelj, V.
.K
quadratic search, hash code, scatter storage, table size
.I 2771
.T
The Synthesis of Solids Bounded by Many Faces
.W
A technique is presented which allows a class
of solid objects to be synthesized and stored
using a computer.  Synthesis begins with primitive solids
like a cube, wedge, or cylinder.  Any solid
can be moved, scaled, or rotated.  Solids may also be
added together or subtracted.  Two algorithms to
perform addition are described.  For practical designers,
the technique has the advantage that operations
are concise, readily composed, and are given in terms
of easily imagined solids.Quite short sequences
of operations suffice to build up complex solids bounded by many faces.
.A
Braid, I. C.
.K
computational geometry, computer-aided design,
graphics, machined components, polyhedra, shape
synthesis, three-dimensional modeling
.I 2772
.T
On Maintenance of the Opportunity List
for Class-Teacher Timetable Problems
.W
One of the principal components of procedures
for the solution of class-teacher timetable problems
is that for maintenance of the opportunity list.  Opportunity
list maintenance methods are based on necessary
conditions for the existence of a solution. A general
framework for necessary conditions, together with
four specific sets of necessary conditions, is given.
.A
Smith, G.
.K
combinatorial, necessary conditions, opportunity
list, schedule,school timetable, timetable
.I 2773
.T
A Weighted Buddy Method for Dynamic Storage Allocation (Corrigendum)
.A
Shen, K. K.
Peterson, J. L.
.I 2774
.T
Remark on Algorithm 475
.A
Frederick, L. W.
.I 2775
.T
The Dilogarithm Function of a Real Argument [S22] (Algorithm 490)
.A
Ginsberg, E. S.
Zaborowski, D.
.K
dilogarithm
.I 2776
.T
Computer Networks in Higher Education: Socio-Economic-Political Factors
.W
This study presents the results of a nationwide
survey of computer networks in higher education
conducted during 1971-73.  Five major and 18 minor networks
were identified.  The five major networks
included: the ARPA Net, the California State College network,
the University of Iowa/Iowa State University
network, the Michigan Educational Research Information Triad,
Inc., and the Triangle Universities Computation
Center network in North Carolina. In-depth studies were
conducted of the latter two nets.  Based on the
experiences of these operating networks, a number of factors
are identified for consideration in developing
networks.  Finally, recommendations are advanced regarding
the development of networks in higher education
in the future.
.A
Chambers, J. A.
Poore, R. V.
.K
networks, higher education
.I 2777
.T
On a Solution to the Cigarette Smoker's
Problem (Without Conditional Statements)
.W
This report discusses a problem first introduced
by Patil, who has claimed that the cigarette
smoker's problem cannot be solved using the P and V operations
introduced by Dijkstra unless conditional
statements are used.  An examination of Patil's proof
shows that he has established this claim only under
strong restrictions on the use of P and V.  These restrictions
eliminate programming techniques used
by Dijkstra and others since the first introduction
of the semaphore concept.  This paper contains a
solution to the problem.  It also discusses the need
for the generalized operators suggested by Patil.
.A
Parnas, D. L.
.K
operating systems, co-operating processes,process
synchronization primitives
.I 2778
.T
Perturbations of Eigenvalues of Non-normal Matrices (Corrigendum)
.A
Sluis, A.
.I 2779
.T
Discrete Least Squares Polynomial Fits
.W
The recurrence relation between orthogonal polynomials
is widely used for discrete least squares
data fitting.  A variant of the classical algorithm
which has better numerical properties is presented
and the reason for its improved performance is explained.
.A
Shampine, L. F.
.K
orthogonal polynomials, data fitting, least squares,
recurrence relation between orthogonal polynomials,
residual
.I 2780
.T
On Computing Certain Elements of the Inverse of a Sparse Matrix
.W
A recursive algorithm for computing the inverse
of a matrix from the LU factors based on relationships
in Takahashi, et al., is examined.  The formulas for the
algorithm are given; the dependency relationships
are derived; the computational costs are developed; and some
general comments on application and stability
are made.
.A
Erisman, E. M.
Tinney, W. F.
.K
sparse matrices, triangular factorization, elements
of inverse, tridiagonal matrix, sensitivities
.I 2781
.T
The Algorithm Sequential Access Method:
An Alternative to Index Sequential
.A
Whitt, J. D.
Sullenberger, A. G.
.K
keys, direct access method, sequential access
method, randomizing information retrieval
.I 2782
.T
A Reply to Gentleman and Marovich
.A
Karp, R. A.
.K
high-level languages, philosophy of language design
.I 2783
.T
The Algorithm SELECT-for Finding the ith
Smallest of n Elements [M1] (Algorithm 489)
.A
Floyd, R. W.
Rivest, R. L.
.K
selection, medians, quantiles
.I 2784
.T
Expected Time Bounds for Selection
.W
A new selection algorithm is presented which
is shown to be very efficient on the average,
both theoretically and practically.  The number of comparisons
used to select the ith smallest of n numbers
is n+min(i,n-i)+o(n).  A lower bound within 9
percent of the above formula is also derived.
.A
Floyd, R. W.
Rivest, R. L.
.K
selection, computational complexity, medians, tournaments, quantiles
.I 2785
.T
Glypnir-A Programming Language for Illiac IV
.W
GLYPNIR is one of the earliest existing languages
designed for programming the Illiac IV computer.
The syntax of the language is based on ALGOL 60, but has
been extended to allow the programmer explicitly
to specify the parallelism of his algorithm in terms of 64-word
vectors.  This paper describes the characteristics,
goals and philosophy of the language, and discusses some
of the problems associated with parallel computer
architectures.
.A
Lawrie, D. H.
Layman, T.
Baer, D.
Randal, J. M.
.K
GLYPNIR, Illiac IV, Programming language,
parallel computation, parallel architecture
.I 2786
.T
A System for Typesetting Mathematics
.W
This paper describes the design and implementation
of a system for typesetting mathematics.
 The language has been designed to be easy to learn
and to use by people (for example, secretaries and
mathematical typists) who know neither mathematics nor
typesetting.  Experience indicates that the language
can be learned in an hour or so, for it has few rules
and fewer exceptions.  For typical expressions,
the size and font changes, positioning, line drawing, and
the like necessary to print according to mathematical
conventions are all done automatically.  For example,
the input sum from i=o to infinity x sub i=pi over
2 produces (formula).  The syntax of the language is specified
by a small context-free grammar; a compiler-compiler
is used to make a compiler that translates this language
into typesetting commands.  Output maybe produced
on either a phototypesetter or on a terminal with forward
and reverse half-line motions.  The system
interfaces directly with text formatting programs, so
mixtures of text and mathematics may be handled
simply.  This paper was typeset by the authors using the system described
.A
Kernighan, B. W.
Cherry, L. L.
.K
typesetting, photocomposition,compiler-compiler,
graphics, printing, text processing.
.I 2787
.T
Matrix Reduction-An Efficient Method
.W
The paper describes an efficient method for
reduction of the binary matrices which arise in
some school time-tabling problems.  It is a development
of that described by John Lions.  It has been
generalized and adapted to fit into the complete timetabling
process; to use a more compact data representation
and more efficient processing techniques; to take fuller
advantage of possible available previous knowledge
about the matrix.  And it is designed as a structured
program, which can readily be coded by the reader
in the high level or low level programming language
of his choice.  Practical tests of the method have
shown it to be a good basis for a realistic timetabling algorithm.
.A
Johnston, H. C.
Hoare, C. A. R.
.K
binary matrices, matrix reduction, tight set, school
timetable construction, structured programming
.I 2788
.T
Finding Circles by an Array of Accumulators
.A
Kimme, C.
Balard, D.
Sklansky, J.
.K
picture processing, pattern recognition, curve detection,line fitting
.I 2789
.T
A Minimal Spanning Tree Clustering Method (Algorithm R479)
.A
Magnuski, H. S.
.I 2790
.T
The Elementary Circuits of a Graph (Algorithm R459)
.A
Syslo, M. M.
.I 2791
.T
Exact Probabilities for R x C Contingency Tables (Algorithm R434)
.A
Hancock, T. W.
.I 2792
.T
Jacobi Polynomials (Algorithm R332)
.A
Skovgaard, O.
.I 2793
.T
Chi-Square Quantiles (Algorithm C451)
.A
Knight,W.
.I 2794
.T
State-Space, Problem-Reduction, and Theorem Proving-Some Relationships
.W
This paper suggests a bidirectional relationship
between state-space and problem-reduction
representations. It presents a formalism based on multiple-input
and multiple-output operators which
provides a basis for viewing the two types of representations
in this manner.  A representation of the
language recognition problem which is based on the Cocke
parsing algorithm is used as an illustration.
 A method for representing problems in first-order logic
in such a way that the inference system employed
by a resolution-based theorem prover determines whether
the set of clauses is interpreted in the state-spacer
mode or in the problem-reduction mode is presented.
 The analogous concepts in problem-reduction and
theorem proving, and the terminology used to refer to them,
are noted.  The relationship between problem-reduction,
input resolution, and linear resolution is discussed.
.A
VanderBrug, G. J.
Minker, J.
.K
artificial intelligence, state-space representation,
problem-reduction representation, theorem
proving, language recognition
.I 2795
.T
Sentence Paraphrasing from a Conceptual Base
.W
A model of natural language based on an underlying
language-free representation of meaning
is described.  A program based on this model is able
to produce sentence paraphrases which demonstrate
understanding with respect to a given context.  This
generator operates in conjunction with a natural
language analyzer and a combined memory and inference model.
 In generating sentences from meaning structures,
the program employs both the information retrieval and
deduction capabilities of the memory model.  The
model encompasses several diverse classes of linguistic
knowledge, which include: (1) executable tests
of conceptual properties stored in discrimination nets;
(2) information relating conceptual to syntactic
roles, stored in a word-sense dictionary, and (3) surface
grammatical knowledge, stored in a formal grammar.
.A
Goldman, N. M.
.K
artificial intelligence, natural language processing,
language generation, models of cognitive
processes, semantic representation
.I 2796
.T
Monitors: An Operating System Structuring Concept (Corrigendum)
.A
Hoare, C. A. R.
.I 2797
.T
A First Order Approximation to the Optimal
Checkpoint Interval (Corrigendum)
.A
Young, J. W.
.I 2798
.T
Analysis of Interleaved Memory Systems Using Blockage Buffers
.W
A model of interleaved memory systems is presented,
and the analysis of the model by Monte
Carlo simulation is discussed.  The simulations investigate
the performance of various system structures,
i.e. schemes for sending instruction and data requests
to the memory system.  Performance is measured
by determining the distribution of the number of memory
modules in operation during a memory cycle.
An important observation from these investigations is that
separately grouping instruction and data requests
for memory can substantially increase the average number
of memory modules in operation during a memory
cycle.  Results of the simulations and an analytical
study are displayed for various system structures.
.A
Burnett, G. J.
Coffman, E. G. Jr.
.K
interleaved memory systems, modular memory systems,
memory performance analysis, blockage buffer,
conflict buffer, simulation, Monte Carolo simulation
.I 2799
.T
Stably Updating Mean and Standard Deviation of Data
.W
By considering the (sample) mean of a set of
data as a fit to this data by a constant function,
a computational method is given based on a matrix formulation
and Givens transformations. The (sample)
mean and standard deviation can be updated as data
accumulates.  The procedure is numerically stable
and does not require storage of the data.  Methods for
dealing with weighted data and data removal are
presented.  When updating the mean and square of the
standard deviation, the process requires no square
roots.
.A
Hanson, R. J.
.K
mean, standard deviation, least squares, Givens
transformation, updating estimates, removing data
.I 2800
.T
Connections Between Accuracy and Stability
Properties of Linear Multistep Formulas
.W
This paper is concerned with stability and accuracy
of families of linear k-step formulas depending
on parameters, with particular emphasis on the numerical
solution of stiff ordinary differential equations.
 An upper bound, p=k, is derived for the order of accuracy
of A(inf)-stable formulas.  Three criteria
are given for A(0)-stability.  It is shown that (1) for
p=k, k arbitrary, A(inf)-stability implies certain
necessary conditions for A(0)-stability and for strict
stability (meaning that the extraneous roots of
p(psi) satisfy |psi|<1); (2) for p=k=2,3,4,and 5, A(inf)-stability
(for k=5 together with another constraint)
implies strict stability; and (3) for certain one-parameter
classes of formulas with p=k=3,4,and/or 5,
A(inf)-stability implies A(0)-stability.
.A
Liniger, W.
.K
stiff equations, parametrized linear multistep formulas,
order of accuracy, A(0)-stability, A(inf)-stability,
strict stability
.I 2801
.T
Storage-Efficient Representation of Decimal Data
.W
Usually n decimal digits are represented by
4n bits in computers.  Actually, two BCD digits
can be compressed optimally and reversibly into 7 bits,
and three digits into 10 bits, by a very simple
algorithm based on the fixed-length combination of two
variable field-length encodings.  In over half
of the cases the compressed code results from the conventional
BCD code by simple removal of redundant
0 bits.  A long decimal message can be subdivided into
three-digit blocks, and separately compressed;
the result differs from the asymptotic minimum length
by only 0.34 percent.  The hardware requirement
is small, and the mappings can be done manually.
.A
Chi Chen, T.
Ho, I. T.
.K
binary-coded decimal digits, decimal data storage
.I 2802
.T
The New Math of Computer Programming
.W
Structured programming has proved to be an important
methodology for systematic program design
and development.  Structured programs are identified
as compound function expressions in the algebra
of functions. The algebraic properties of these function
expressions permit the reformulation (expansion
as well as reduction) of a nested subexpression independently
of its environment, thus modeling what
is known as stepwise program refinement as well as program
execution.  Finally, structured programming
is characterized in terms of the selection and solution
of certain elementary equations defined in the
algebra of functions.  These solutions can be given in
general formulas, each involving a single parameter,
which display the entire freedom available
in creating correct structured programs.
.A
Mills, H. D.
.K
structured programming, algebra of functions,
stepwise refinement, program correctness
.I 2803
.T
Pseudoinverses and Conjugate Gradients
.W
This paper is devoted to the study of connections
between pseudoinverses of matrices and conjugate
gradients and conjugate direction routines.
.A
Hestenes, M. R.
.K
pseudoinverse, conjugate gradients, hermitian matrix, minimization
.I 2804
.T
Elementary Divisors of Tensor Products
.W
The elementary divisors of a tensor product
of linear transformations have been known for 40
years.  This paper provides a short, easily accessible
proof of these results, and points out an interesting
combinatorial consequence of the proof.
.A
Marcus, M.
Robinson, H.
.K
elementary divisors, tensor products, linear transformations
.I 2805
.T
Perturbations of Eigenvalues of Non-normal Matrices
.W
The problem considered is to give bounds for finite
perturbations of simple and multiple eigenvalues
of nonnormal matrices, where these bounds are in terms
of the eigenvalues, the departure from normality,
and the Frobenius norm of the perturbation matrix, but
not in terms of the eigen system.  The bounds which
are derived are shown to be almost attainable for any set of matrices.
.A
van der Sluis, A.
.K
perturbation of eigenvalues, non-normal matrices,
departure from normality, Gershgorin circles
.I 2806
.T
Two Hadamard Numbers for Matrices
.W
A discussion is given of two functions of the entries
of a square matrix, both related to Hadamard's
determinant theorem, which have some merits as alternatives
to norm-bound "condition numbers."  One (for
linear systems) is known; the other (for eigen systems) seems to be new.
.A
Birkhoff, G.
.K
matrices, eigenvalues, norms, condition numbers,
error analysis, Gram-Schmidt orthogonalization
.I 2807
.T
On the Stability of Gauss-Jordan Elimination with Pivoting
.W
The stability of the Gauss-Jordan algorithm
with partial pivoting for the solution of general
systems of linear equations is commonly regarded as suspect.
 It is shown that in many respects suspicions
are unfounded, and in general the absolute error in the solution
is strictly comparable with that corresponding
to Gaussian elimination with partial pivoting plus back
substitution.  However, when A is ill conditioned,
the residual corresponding to the Gauss-Jordan solution
will often be much greater than that corresponding
to the Gaussian elimination solution.
.A
Peters, G.
Wilkinson, J. H.
.K
Gauss-Jordan algorithm, Gaussian elimination, back-substitution,
backward error analysis, bounds
for error in solution, bound for residual
.I 2808
.T
The Lemniscate Constants
.W
The lemniscate constants, and indeed some
of the methods used for actually computing them,
have played an enormous part in the development of
mathematics.  An account is given here of some of
the methods used-most of the derivations can be made
by elementary methods.  This material can be used
for teaching purposes, and there is much relevant and
interesting historical material.  The acceleration
methods developed for the purpose of evaluating
these constants are useful in other problems.
.A
Todd, J.
.K
lemniscate, acceleration, elliptic functions, Euler transformation
.I 2809
.T
Positivity and Norms
.W
Following some lines of joint work with A.
S. Householder, the character and use of algebraic
methods in the theory of norms is demonstrated.  New results
concerning norms with values in an Archimedian
vector lattice (not necessarily being totally ordered)
are given, in particular for the generalization
of order unit norms, L-norms and M-norms.  An example
of application to operator norms is given concerning
contraction properties of positive operators.
.A
Bauer, F. L.
.K
matrices, norms, positivity, numerical range, positivity
cones, vector lattice,absolute, monotonic
.I 2810
.T
Professionalism in the Computing Field
.W
The term professional means different things
to different people; nevertheless, there are certain
general technical and social standards normally associated
with a professional.  Further, the term is
more generally applied to the practitioner rather than
to the researcher.  But within the rather broad
definition specified, the computing practitioner is,
as yet, not regarded as a professional.  Each of
the four types of institutions-academic, industry, government,
and the professional society- that educate,
employ, regulate, and mold the practitioner contributes
to the "nonprofessional" status of the computing
practitioner.  The roles of these institutions are examined,
various shortcomings are noted, and recommended
changes are suggested.  In the last analysis, professional
status is not bestowed; it is earned.  However,
universities and industry, specifically, can make certain
 improvements to help the computing practitioner
achieve professional status.
.A
Finerman, A.
.K
professional aspects, educational programs, industry
attitudes, professional societies, licensing
and certification
.I 2811
.T
Structural Pattern Recognition Of Carotid Pulse
Waves Using A General Waveform Parsing System
.W
A general waveform parsing system with application
to structural pattern recognition of carotid
pulse waves is described.  The carotid arterial pulse
wave is of medical importance because of variation
in its structure induced by arterial aging and cardiovascular
disease.  The syntax-driven waveform analysis
system has been applied with good results to these pulse
waves to detect and measure structural variations.
 The waveform parsing system is modeled on a compiler-compiler
system and allows the user to enter application
specific information as data.  It is thus general
enough to be applicable to other waveforms.
.A
Stockman, G.
Kanal, L.
Kyle, M. C.
.K
structural pattern recognition, parsing, waveform analysis, pulse waves
.I 2812
.T
Computer-Aided Analysis and Design of Information Systems
.W
This paper describes the use of computer-aided
analysis for the design and development of an
integrated financial management system by the Navy Material
Command Support Activity (NMCSA).  Computer-aided
analysis consists of a set of procedures and computer
programs specifically designed to aid in the process
of applications software design, computer selection
and performance evaluation.  There are four major
components: Problem Statement Language, Problem Statement
Analyzer, Generator of Alternative Designs,
and Performance Evaluator. The statement of requirements
was written in ADS (Accurately Defined Systems)
and analyzed by a Problem Statement Analyzer for ADS.
 The ADS problem definition was supplemented with
additional information in order to create a complete
problem definition.  The analyzed problem statement
was translated to the form necessary for use by the
SODA (Systems Optimization and Design Algorithm)
program for the generation of alternative specifications
of program modules and logical database structures.
.A
Nunamaker, J. F. Jr.
Konsynski, B. R. Jr.
Ho, T.
Singer, C.
.K
computer-aided analysis, information systems, logical
system design, problem statement language,
problem statement analyzer, physical system design,
accurately defined systems, systems optimization
and design algorithm
.I 2813
.T
The Computer Science and Engineering Research Study (COSERS)
.W
The Computer Science and Engineering Research
Study (COSERS) is briefly described.  The motivation,
organization, and schedule for this NSF supported study
are given.  For possible further reference, the
subject area panel chairmen and the members
of the Steering Committee are identified.
.A
Arden, B.
.K
computer science research, computer engineering
research, national research study
.I 2814
.T
Roster of Programming Languages for 1974-75
.A
Sammet, J. E.
.I 2815
.T
High-Level Binding with Low-Level Linkers
.W
An easy to implement scheme is described by
which a compiler can enforce agreement between
complex data types in separately compiled modules.
 The scheme is designed to work with any existing
link editor or linking loader, no matter how deficient.
 Obscure run-time errors caused by inconsistent
usages are forestalled by static errors detected at linking time.
.A
Hamlet, R. G.
.K
separate compilation, binding, linking, strong typing
.I 2816
.T
Optimal Reorganization of Distributed Space Disk Files
.W
In most database organizations, the cost of accessing
the database will increase due to structural
changes caused by updates and insertions.  By reorganizing
the database,the access costs can be reduced.
 A basic problem is to establish the proper tradeoff between
performance, storage costs, and reorganization
costs.  This paper considers the optimum points at which
to reorganize a database.  A disk file organization
which allows for distributed free space is described.
 A cost function describing the excess costs due
to physical disorganization is defined, and this function
is minimized to obtain the optimum reorganization
points.  Numerical examples based on the characteristics
of existing disk storage devices are given.
.A
Maruyama, K.
Smith, S. E.
.K
disk file, free space,retrieval, insertion, deterioration, reorganization
.I 2817
.T
The Notions of Consistency and Predicate Locks in a Database System
.W
In database systems, users access shared data
under the assumption that the data satisfies
certain consistency constraints.  This paper defines the
concepts of transaction, consistency and schedule
and shows that consistency requires that a transaction
cannot request new locks after releasing a lock.
 Then it is argued that a transaction needs to lock a logical
rather than a physical subset of the database.
 These subsets may be specified by predicates.  An
implementation of predicate locks which satisfies
the consistency condition is suggested.
.A
Eswarran, K..
Gray, J..
Lorie, R..
Traiger, I. L.
.K
consistency, lock, database, concurrency, transaction
.I 2818
.T
Interference in Multiprocessor Computer
Systems with Interleaved Memory (Corrigendum)
.A
Baskett, F.
Smith, A. J.
.I 2819
.T
Experiments in Text File Compression
.W
A system for the compression of data files,
viewed as strings of characters, is presented.
 The method is general, and applies equally well to
English, to PL/I, or to digital data.  The system
consists of an encoder, an analysis program, and a decoder.
  Two algorithms for encoding a string differ
slightly from earlier proposals.  The analysis program attempts
to find an optimal set of codes for representing
substrings of the file.  Four new algorithms for this
operation are described and compared.  Various
parameters in the algorithms are optimized to obtain
a high degree of compression for sample texts.
.A
Rubin, F.
.K
text compression, data file compaction, Huffman
codes, N-gram encoding, comparison of algorithms
.I 2820
.T
The Design and Implementation of a Table Driven,
Interactive Diagnostic Programming System
.W
CAPS is a highly interactive diagnostic compiler/interpreter
that allows beginning programmers
to prepare, debug, and execute fairly simple programs
at a graphics display terminal.  Complete syntax
checking and most semantic analysis is performed as
the program is entered and as it is subsequently
edited.  Analysis is performed character by character.
 The most remarkable feature of CAPS is its ability
to automatically diagnose errors both at compile time
and at run time.  Errors are not automatically
corrected.  Instead, CAPS interacts with the student to help
him find the cause of his error.  Most components
of CAPS are table driven, both to reduce the space needed
for implementation and to increase the flexibility
of the multilingual system.  Over 500 students have used
CAPS to learn Fortran, PL/I, or Cobolin conjunction
with a computer assisted course on introductory computer science.
.A
Wilcox, T. R.
Davis, A. M.
Tindall, M. H.
.K
interactive programming, table driven compilers,
error correction, interpreters, debugging, computer
assisted instruction, computer science education
.I 2821
.T
Cobol Under Control
.W
A sample set of Cobol programming standards
is offered.  These standards constrain code to
be developed in a "structured" form for both data and
control structures.  They do not require syntax
beyond the existing Cobol language and in fact utilize
a typical limited subset of the 1974 ANS Cobol
standard.  These standards have proved extremely valuable
in practice and have reduced the cost and time
to produce and maintain large software systems that have
been deployed in live multiple customer environments.
.A
Ledgard, H. F.
Cave, W. C.
.K
Cobol, structured programming,software development, program standards
.I 2822
.T
Homilies for Humble Standards
.W
Copyright 1976, Association for Computing
Machinery, Inc. General permission to republish,
but not for profit, all or part of this material is granted
provided that ACM's copyright notice is given
and that reference is made to the publication, to its
data of issue, and to the fact that reprinting
privileges were granted by permission of
the Association for Computing Machinery.
.A
Ross, D. T.
.K
standards, CASE Standards criteria for standards, standardization
.I 2823
.T
The Status of Women and Minorities in Academic Computer Science
.W
The results of a survey concerning women and
minority students and faculty in computer science
during the years 1971 to 1975 are presented.  Analysis
of the data indicated that effective affirmative
action programs for recruitment into graduate degree
programs are needed to enlarge the number of women
and minorities qualified for later employment in computer
science.  Also, possible discrimination in
employment of women and minority graduate students was revealed.
.A
Montanelli, R. G. Jr.
Mamrak, S. A.
.K
discrimination against women, discrimination against
minorities, graduate students, undergraduate
students, academic employment, faculty, computer science
degree programs, affirmative action, Title VII,
Title IX
.I 2824
.T
An Improvement to Martin's Algorithm for
Computation of Linear Precedence Functions
.A
Duong-Kien, C.
Hoffmann, H. J.
Muth, D.
.K
syntax analysis, precedence functions, Boolean matrices
.I 2825
.T
The BMD and BMDP Series of Statistical Computer Programs
.A
Frane, J. W.
.K
analysis of variance, cluster analysis, contingency
tables, data analysis, discriminant analysis,
factor analysis, graphics, outliers, regression, time series, transformations
.I 2826
.T
Interactive Skeleton Techniques for Enhancing
Motion Dynamics in Key Frame Animation
.W
A significant increase in the capability for
controlling motion dynamics in key frame animation
is achieved through skeleton control.  This technique
allows an animator to develop a complex motion
sequence by animating a stick figure representation
of an image.  This control sequence is then used
to drive an image sequence through the same movement.
 The simplicity of the stick figure image encourages
a high level of interaction during the design stage.
Its compatibility with the basic key frame animation
technique permits skeleton control to be applied selectively
to only those components of a composite
image sequence that require enhancement.
.A
Burtnyk, N.
Wein, M.
.K
interactive graphics, computer generated animation,
key frame animation, interactive skeleton control,
stick figure animation
.I 2827
.T
A Parametric Algorithm for Drawing Pictures
of Solid Objects Composed of Quadric Surfaces
.W
An algorithm for drawing pictures of three-dimensional
objects, with surfaces made up of patches
of quadric surfaces, is described.  The emphasis of
this algorithm is on calculating the intersections
of quadric surfaces. A parameterization scheme is used.
 Each quadric surface intersection curve (QSIC)
is represented as a set of coefficients and parameter
limits.  Each value of the parameter represents
at most two points, and these may easily be distinguished.
 This scheme can find the coordinates of points
of even quartic (fourth-order) intersection curves, using
equations of no more than second order.  Methods
of parameterization for each type of OSIC are discussed,
as well as surface bounding and hidden surface
removal.
.A
Levin, J.
.K
computer graphics, hidden surface removal,
quadric surface intersection curves
.I 2828
.T
Hierarchical Geometric Models for Visible Surface Algorithms
.W
The geometric structure inherent in the definition
of the shapes of three-dimensional objects
and environments is used not just to define their relative
motion and placement, but also to assist in
solving many other problems of systems for producing
pictures by computer.  By using an extension of
traditional structure information, or a geometric hierarchy,
five significant improvements to current
techniques are possible.  First, the range of complexity
of an environment is greatly increased while
the visible complexity of any given scene is kept within
a fixed upper limit.  Second, a meaningful way
is provided to vary the amount of detail presented in
a scene.  Third, "clipping" becomes a very fast
logarithmic search for the resolvable parts of the environment
within the field of view.  Fourth, frame
to frame coherence and clipping define a graphical
"working set," or fraction of the total structure
that should be present in primary store for immediate
access by the visible surface algorithm.  Finally,
the geometric structure suggests a recursive descent,
visible surface algorithm in which the computation
time potentially grows linearly with the visible complexity of the scene.
.A
Clark, J. H.
.K
visible surface algorithms, hidden surface algorithms,
hierarchical data structures, geometric
models
.I 2829
.T
Texture and Reflection in Computer Generated Images
.W
In 1974 Catmull developed a new algorithm
for rendering images of bivariate surface patches.
 This paper describes extensions of this algorithm in
the areas of texture simulation and lighting models.
 The parameterization of a patch defines a coordinate
system which is used as a key for mapping patterns
onto the surface.  The intensity of the pattern at each
picture element is computed as a weighted average
of regions of the pattern definition function. The shape
and size of this weighting function are chosen
using digital signal processing theory.  The patch rendering
algorithm allows accurate computation of
the surface normal to the patch at each picture element,
permitting the simulation of the mirror reflections.
 The amount of light coming from a given direction is
modeled in a similar manner to the texture mapping
and then added to the intensity obtained from the texture
mapping.  Several examples of images synthesized
using these new techniques are included.
.A
Blinn, J. F.
Newell, M. E.
.K
computer graphics, graphic display, shading, hidden surface removal
.I 2830
.T
A Practitioner's Guide to Addressing Algorithms (Corrigendum)
.A
Severance, D. G.
Duhne, R. A.
.I 2831
.T
Analysis of the PFF Replacement Algorithm
via a Semi-Markov Model (Corrigendum)
.A
Chu, W. W.
Opderbeck, H.
.I 2832
.T
Faster Retrieval from Context Trees (Corrigendum)
.W
Context trees provide a convenient way of
storing data which is to be viewed as a hierarchy
of contexts.  This note presents an algorithm which improves
on previous context tree retrieval algorithms.
It is based on the observation that in typical uses context
changes are infrequent relative to retrievals,
so that data can be cached to speed up retrieval.  A retrieval
is started from the position of the previous
retrieval and auxiliary structures are built up to make
the search rapid.  Algorithms for addition and
deletion of data and for garbage collection are outlined.
.A
Wegbreit, B.
.K
context trees, frame problem, variable bindings, data structures
.I 2833
.T
An Efficient, Incremental, Automatic Garbage Collector
.W
This paper describes a new way of solving
the storage reclamation problem for a system such
as Lisp that allocates storage automatically from a
heap, and does not require the programmer to give
any indication that particular items are no longer useful
or accessible.  A reference count scheme for
reclaiming non-self-referential structures, and a linearizing,
compacting, copying scheme to reorganize
all storage at the users discretion are proposed.  The
algorithms are designed to work well in systems
which use multiple levels of storage, and large virtual
address space.  They depend on the fact that
most cells are referenced exactly once, and that reference
counts need only be accurate when storage
is about to be reclaimed.  A transaction file stores changes
to reference counts, and a multiple reference
table stores the count for items which are referenced more than once.
.A
Deutsch, L. P.
Bobrow, D. G.
.K
storage management, garbage collection, Lisp
.I 2834
.T
Efficient Generation of the Binary
Reflected Gray Code and Its Applications
.W
Algorithms are presented to generate the n-bit
binary reflected Gray code and codewords of
fixed weight in that code.  Both algorithms are efficient
in that the time required to generate the next
element from the current one is constant.  Applications
to the generation of the combinations of n things
taken k at a time, the compositions of integers, and
the permutations of a multiset are discussed.
.A
Bitner, J. R.
Ehrlich, G.
Reingold, E. M.
.K
Gray code, combinations, subsets, compositions, combinatorial computing
.I 2835
.T
Recursion Analysis for Compiler Optimization
.W
A relatively simple method for the detection
of recursive use of procedures is presented for
use in compiler optimization.  Implementation considerations
are discussed, and a modification of the
algorithm is given to further improve optimization.
 This analysis can also be used to determine what
possible subset of values could be assumed by variables
which can only take on a relatively small discrete
set of values.  The most common are parameters of variables
assuming values of label, procedure, or Pascal's
enumerated type.
.A
Walter, K. G.
.K
recursion, compiler optimization
.I 2836
.T
Weighted Derivation Trees
.W
The nodes of a weighted derivation tree are associated
with weighting functions over the vocabulary
of a context-free grammar.  An algorithm is presented
for constructing the optimal derivation tree having
the same structure as a given weighted derivation tree.
 In addition, the correctness of the algorithm
is established.  The method may be applied to problems
involving probabilistic parsing or combinatorial
optimization.
.A
Loui, M. C.
.K
derivation tree, parse tree, probabilistic grammar,
structural ambiguity, combinatorial optimization
.I 2837
.T
New Upper Bounds for Selection
.W
The worst-case minimum number of comparisons
complexity Vi(n) of the i-th selection problem
is considered.  A new upper bound for Vi(n) improves the
bound given by the standard Hadian-Sobel algorithm
by a generalization of the Kirkpatrick-Hadian-Sobel
algorithm, and extends Kirkpatrick's method to a
much wider range of application.  This generalization
compares favorably with a recent algorithm by Hyafil.
.A
Yap, C. K.
.K
selection problem, algorithms, comparison problems,
concrete computational complexity, upper bounds,
worst-case analysis
.I 2838
.T
Analysis of an Algorithm for Real Time Garbage Collection
.W
A real time garbage collection system avoids
suspending the operations of a list processor
for the long times that garbage collection normally requires
by performing garbage collection on a second
processor in parallel with list processing operations,
or on a single processor time-shared with them.
 Algorithms for recovering discarded list structures in
this manner are presented and analyzed to determine
sufficient conditions under which the list processor never
needs to wait on the collector.  These techniques
are shown to require at most twice as much processing
power as regular garbage collectors, if they are
used efficiently.  The average behavior of the program
is shown to be very nearly equal to the worst-case
performance, so that the sufficient conditions are also
suitable for measuring the typical behavior of
the algorithm.
.A
Wadler, P. L.
.K
garbage collection, storage reclamation, list
processing, Lisp, time-sharing, multiprocessing,
parallel processing, real time, data structures, analysis of algorithms
.I 2839
.T
An Insertion Technique for One-Sided Height-Balanced Trees
.W
A restriction on height-balanced binary trees
is presented.  It is seen that this restriction
reduces the extra memory requirements by half (from
two extra bits per node to one) and maintains fast
search capabilities at a cost of increased
time requirements for inserting new nodes.
.A
Hirschberg, D. S.
.K
balanced, binary, search, trees
.I 2840
.T
Protection in Operating Systems
.W
A model of protection mechanisms in computing
systems is presented and its appropriateness
is argued.  The "safety" problem for protection systems
under this model is to determine in a given situation
whether a subject can acquire a particular right to
an object.   In restricted cases, it can be shown
that this problem is decidable, i.e. there is an algorithm
to determine whether a system in a particular
configuration is safe.  In general, and under surprisingly
weak assumptions, it cannot be decided if
a situation is safe. Various implications of this fact are discussed.
.A
Harrison, M. A.
Ruzzo, W. L.
Ullman, J. D.
.K
protection, protection system, operating
system, decidability, Turing machine
.I 2841
.T
Designing Surfaces in 3-D
.W
An experimental system for computer-aided
design of free-form surfaces in three dimensions
is described. The surfaces are represented in the system
as parametric basis splines. The principal features
of the system are: (1) the surfaces are rendered as isoparametric
line drawings on a head-mounted display,
and they are designed with the aid of a three-dimensional
"wand," which allows 3-D movements of the points
controlling the shapes of the surfaces, (2) all of the
interactions with the surfaces are in real-time,
and (3) the mathematical formulations used assume no
knowledge of them by the user of the system.  Also
examined are some of the features that should be part
of a practical 3-D system for designing space-forms.
.A
Clark, J. H.
.K
real-time graphics, computer-aided design,
picture processing, B-splines, 3-D displays
.I 2842
.T
The Denotational Semantics of Programming Languages
.W
This paper is a tutorial introduction to the
theory of programming language semantics developed
by D. Scott and C. Strachey.  The application of the theory
to formal language specification is demonstrated
and other applications are surveyed. The first language
considered, LOOP, is very elementary and its
definition merely introduces the notation and methodology
of the approach.  Then the semantic concepts
of environments, stores, and continuations are introduced
to model classes of programming language features
and the underlying mathematical theory of computation
due to Scott is motivated and outlined.  Finally,
the paper presents a formal definition of the language GEDANKEN.
.A
Tennent, R. D.
.K
semantics, programming language, applicative, imperative,
environment, store, continuation, theory
of computation, higher-order function, recursive definition, LOOP, GEDANKEN
.I 2843
.T
Tools and Philosophy for Software Education
.W
This paper describes a set of tools and a philosophy
for teaching software that have been found
very useful in course at MIT over the past seven years.
 The tools include programs such as simulators,
graders, compilers, and monitor.  These allow the instructor
to augment the basic concepts with relevant,
exciting, and economical student project activities.
.A
Donovan, J. J.
.K
software education, simulators, grading programs, student assignments
.I 2844
.T
Heaps Applied to Event Driven Mechanisms
.A
Gonnet, G. H.
.K
discrete event simulation, event-scanning
mechanisms, priority queues, heaps
.I 2845
.T
A Buddy System Variation for Disk Storage Allocation
.W
A generalization of the buddy system for storage
allocation is described. The set of permitted
block sizes {SIZE(i)}, i=0,n, must satisfy the condition
SIZE(i)=SIZE(i-1)+SIZE(i-k(i)) where k may be
any meaningful integral-valued function.  This makes it
possible to force logical storage blocks to coincide
with physical storage blocks, such as tracks and cylinders.
.A
Burton, W.
.K
buddy system, dynamic storage allocation
.I 2846
.T
Compressed Tries
.W
This paper presents a new data structure,
called a compressed trie or C-trie, to be used in
information retrieval systems.  It has the same underlying
m-ary tree structure as a trie, where m is
a parameter of the trie, but whereas the fields of the
nodes in a trie have to be large enough to hold
a key or at least a pointer, the fields in a C-trie are
only one bit long.  In the analysis part of the
paper it will be shown that for a collection of n keys the
retrieval time, measured in terms of bit inspections
of one key, is of the order logm(n) and the storage
requirement of the order n*(m+log2 n) bits.  This
improvement in storage requirements and retrieval time
is achieved at the cost of decreasing the flexibility
of the structure, and therefore updating costs are increased.
 First the C-trie is analyzed as a data
structure, and then several methods of its use
for relatively static databases are discussed.
.A
Maly, K.
.K
data structure, database, m-ary tree, trie,
retrieval time, storage requirement, keys
.I 2847
.T
Sampling from the Gamma Distribution on a Computer
.W
This paper describes a method of generating
gamma variates that appears to be less costly than
Wallace's recently suggested method.  For large shape parameter
(a); the cost of computation is proportional
to (a), whereas Wallace's method is proportional to (a).
 Experimentation by Robinson and Lewis indicates
that for small (a) the method suggested here also dominates
methods recently suggested by Dieter and
Ahrens, albeit those methods dominate for large (a).  The
method suggested here uses the rejection technique.
.A
Fishman, G. S.
.K
gamma variates, reflection method, sampling
.I 2848
.T
Synthesis of Decision Rules
.W
Decision tables can be used as an effective
tool during an interview to record the logic of
processes to be automated.  The result of such an interview
is not a structure of complete decision tables
but rather sets of decision rules.  The purpose of this
paper is to provide a procedure for synthesizing
the decision rules and thus provide an aid in developing
a structure of complete decision tables.
.A
Cheng, C.
Rabin, J.
.K
decision rules, decision tables, logical tables,
logical design, system design, specification language
.I 2849
.T
Ethernet: Distributed Packet Switching for Local Computer Networks
.W
Ethernet is a branching broadcast communication
system for carrying digital data packets among
locally distributed computing stations. The packet
transport mechanism provided by Ethernet has been
used to build systems which can be viewed as either local
computer networks or loosely coupled multiprocessors.
 An Ethernet's shared communication facility, its Ether,
is a passive broadcast medium with no central
control.  Coordination of access to the Ether for packet
broadcasts is distributed among the contending
transmitting stations using controlled statistical arbitration.
 Switching of packets to their destinations
on the Ether is distributed among the receiving stations
using packet address recognition.  Design principles
and implementation are described, based on experience
with an operating Ethernet of 100 nodes along a
kilometer of coaxial cable.  A model for estimating performance
under heavy loads and a packet protocol
for error controlled communication are included for completeness.
.A
Metcalfe, R. M.
Boggs, D. R.
.K
computer networks, packet switching, multiprocessing,
distributed control, distributed computing,
broadcast communication, statistical arbitration
.I 2850
.T
Symbolic Execution and Program Testing
.W
This paper describes the symbolic execution of
programs.  Instead of supplying the normal inputs
to a program (e.g. numbers) one supplies symbols representing
arbitrary values.  The execution proceeds
as in a normal execution except that values may be symbolic
formulas over the input symbols.  The difficult,
yet interesting issues arise during the symbolic execution
of conditional branch type statements.  A
particular system called EFFIGY which provides symbolic
execution for program testing and debugging is
also described.  It interpretively executes programs written
in a simple PL/I style programming language.
 It includes many standard debugging features, the ability
to manage and to prove things about symbolic
expressions, a simple program testing manager, and a program
verifier.  A brief discussion of the relationship
between symbolic execution and program proving is also included.
.A
King, J. C.
.K
symbolic execution, program testing, program debugging,
program proving, program verification,
symbolic interpretation
.I 2851
.T
Formal Verification of Parallel Programs
.W
Two formal models for parallel computation
are presented: an abstract conceptual model and
a parallel-program model.  The former model does not
distinguish between control and data states.  The
latter model includes the capability for the representation
of an infinite set of control states by allowing
there to be arbitrarily many instruction pointers (or
processes) executing the program.  An induction
principle is presented which treats the control and
data state sets on the same ground.  Through the
use of "place variables," it is observed that certain
correctness conditions can be expressed without
enumeration of the set of all possible control states.
 Examples are presented in which the induction
principle is used to demonstrate proofs of mutual exclusion.
 It is shown that assertions-oriented proof
methods are special cases of the induction principle.
A special case of the assertions method, which
is called parallel place assertions, is shown to be
incomplete.  A formalization of "deadlock" is then
presented. The concept of a "norm" is introduced, which
yields an extension, to the deadlock problem,
of Floyd's technique for proving termination.  Also discussed
is an extension of the program model which
allows each process to have its own local variables
and permits shared global variables.  Correctness
of certain forms of implementation is also discussed.
 An Appendix is included which relates this work
to previous work on the satisfiability of certain logical formulas.
.A
Keller, R. M.
.K
parallel program, correctness, verification,
assertions, deadlock, mutual exclusion, Petrinet
.I 2852
.T
The Technology of Computer Center Management: A
Proposed Course for Graduate Professional Programs
in Computer Science or in Information Systems
.W
McFarlan and Nolan have made a strong case for
adding a course on information systems administration
to the 13 courses proposed by the ACM Curriculum Committee
on Computer Education for Management for Graduate
Professional Programs in Information Systems.  This paper
is a report on a course entitled, "The Technology
of Computer Center Management," which has been offered
at Purdue for the past four years.  The course
is suitable either for graduate professional programs
in information systems or for graduate professional
programs in computer science.
.A
Conte, S. D.
Halstead, M. H.
.K
education, information systems administration, computer
center management, computer system performance
.I 2853
.T
A Numbering System for Permutations of Combinations
.A
Knott, G. D.
.K
combinatorics,coding systems, storage mapping functions
.I 2854
.T
Multiprocessing Compactifying Garbage Collection (Corrigendum)
.A
Steele, G. L. Jr.
.I 2855
.T
An Efficient List-Moving Algorithm Using Constant Workspace
.W
An efficient algorithm is presented for moving
arbitrary list structures, using no storage
(apart from program variables) other than that required
to hold the original list and the copy.  The
original list is destroyed as it is moved.  No mark
bits are necessary, but pointers to the copy must
be distinguishable from pointers to the original.  The
algorithm is superior in execution speed to previous
algorithms for the same problem.  Some variations
and extensions of the algorithm are discussed.
.A
Clark, D. W.
.K
list moving, list copying, LISP, space complexity, constant workspace
.I 2856
.T
The Synthetic Approach to Decision Table Conversion
.W
Previous approaches to the problem of automatically
converting decision tables to computer
programs have been based on decomposition.  At any
stage, one condition is selected for testing, and
two smaller problems (decision tables with one less
condition) are created.  An optimal program (with
respect to average execution time or storage space, for
example) is located only through implicit enumeration
of all possible decision trees using a technique such
as branch-and-bound.  The new approach described
in this paper uses dynamic programming to synthesize
an optimal decision tree from which a program can
be created.  Using this approach, the efficiency of creating
an optimal program is increased substantially,
permitting generation of optimal programs for decision
tables with as many as ten to twelve conditions.
.A
Schumacher, H.
Sevcik, K. C.
.K
decision tables, decision trees, dynamic programming, optimal programs
.I 2857
.T
Referencing Lists by an Edge
.W
An edge reference into a list structure is a pair
of pointers to adjacent nodes.  Such a reference
often requires little additional space, but its use can
yield efficient algorithms. For instance, a circular
link between the ends of a list is redundant if the list
is always referenced by that edge, and list traversal
is easier when that link is null.  Edge references also
allow threading of nonrecursive lists, can replace
some header cells, and enhance the famous
exclusive-or-trick to double-link lists
.A
Wise, D. S.
.K
list processing, circular, doubly linked, overlapping
sublist, header cell, pointer, cursor
.I 2858
.T
A Process for the Determination of
Addresses in Variable Length Addressing
.W
An algorithm is presented for the assignment
of instruction addresses and formats under the
following conditions: (1) the length of the instruction varies
as a function of the distance of the instruction
from its target; (2) there exists an optimality criterion
which implies some preferential choices subject
to the addressing constraints.  This may be, for example,
achieving the smallest number of long instructions,
in which case the total code length is minimized, or
minimizing the assigned address of a specified point
in the program.  The algorithm is suitable for arbitrary
program structure and a choice of optimization
criteria.
.A
Frieder, G.
Saal, H. J.
.K
variable length addressing, assembler, paging
.I 2859
.T
Interference in Multiprocessor Computer Systems with Interleaved Memory
.W
This paper analyzes the memory interference
caused by several processors simultaneously using
several memory modules.  Exect results are computed for
a simple model of such a system.   The limiting
value is derived for the relative degree of memory interference
as the system size increases.  The model
of the limiting behavior of the system yields approximate
results for the simple model and also suggests
that the results are valid for a much larger class of models,
including those more nearly like real systems
that the simple model are tested against some measurements
of program behavior and simulations of systems
using memory references from real programs.  The model
results provide a good indication of the performance
that should be expected from real system of this type.
.A
Baskett, F.
Smith, A. J.
.K
memory, memory interference, multiprocessing,
interleaved memory, trace driven simulation
.I 2860
.T
A Practitioner's Guide To Addressing Algorithms
.W
This paper consolidates a number of popular
rules of thumb which have been suggested for the
design of record addressing algorithms, and discusses
the applicability of these rules to large commercial
databases.  Guidelines for selecting identifier transformations,
overflow techniques, loading factors,
bucket sizes, and loading order and considered.  Particular
attention is focused on the reasonableness
of common heuristics for determining primary or secondary
bucket sizes. A mathematical model which explicitly
considers storage device characteristics and time/space
cost tradeoffs is used to analyze the effect
of design parameters on overall system costs.  A
specific design example is presented and solved.
.A
Severance, D.
Duhne, R.
.K
data management, file retrieval, searching, addressing
techniques, hashing functions, synonym resolution,
loading factor, bucket size, heuristic design, rules of thumb
.I 2861
.T
Production and Employment of Ph.D.'s in Computer Science
.A
Taulbee, O. E.
Conte, S. D.
.I 2862
.T
Analysis of the PFF Replacement Algorithm via a Semi-Markov Model
.W
An analytical model is presented to estimate
the performance of the Page Fault Frequency (PFF)
replacement algorithm.  In this model, program behavior
is represented by the LRU stack distance model
and the PFF replacement algorithm is represented by a semi-Markov
model.  Using these models, such parameters
as the inter-page-fault interval distribution, the
probability of the number of distinct pages being
referenced during an inter-page-fault interval, etc. are
able to be analytically determined.  Using these
models to evaluate these parameter values permits study
of the performance of the replacement algorithm
by simulating the page fault events rather than every
page reference event.  This significantly reduces
the required computation time in estimating
the performance of the PFF algorithm.
.A
Chu, W. W.
Opderbeck, H.
.K
PFF replacement algorithm, semi-Markov
model, simulation of replacement algorithm
.I 2863
.T
VMIN-An Optimal Variable-Space Page Replacement Algorithm
.W
A criterion for comparing variable space page
replacement algorithms is presented.  An optimum
page replacement algorithm, called VMIN, is described and
shown to be optimum with respect to this criterion.
The results of simulating VMIN, Denning's working set,
and the page partitioning replacement algorithms
on five virtual memory programs are presented to demonstrate
the improvement possible over the known
realizable variable space algorithms.
.A
Prieve, B. G.
Fabry, R. S.
.K
demand paging, performance measurement, multilevel
memory systems, virtual memory, working set,
page replacement algorithms, optimal page replacement
.I 2864
.T
Characteristics of Program Localities
.W
The term "locality" has been used to denote that
subset of a program's segments which are referenced
during a particular phase of its execution.  A program's
behavior can be characterized in terms of its
residence in localities of various sizes and lifetimes,
and the transitions between these localities.
 In this paper the concept of a locality is made more explicit
through a formal definition of what constitutes
a phase of localized reference behavior, and by a corresponding
mechanism for the detection of localities
in actual reference strings.  This definition provides
for the existence of a hierarchy of localities
at any given time, and the reasonableness of the definition
is supported by examples taken from actual
programs.  Empirical data from a sample of production
Algol 60 programs is used to display distributions
of locality sizes and lifetimes, and these results are
discussed in terms of their implications for the
modeling of program behavior and memory management in virtual memory systems.
.A
Madison, A. W.
Batson, A. P.
.K
program behavior, memory management, locality
.I 2865
.T
Verifying Properties of Parallel Programs: An Axiomatic Approach
.W
An axiomatic method for proving a number
of properties of parallel programs is presented.
Hoare has given a set of axioms for partial correctness,
but they are not strong enough in most cases.
 This paper defines a more powerful deductive system which
is in some sense complete for partial correctness.
 A crucial axiom provides for the use of auxiliary variables,
which are added to a parallel program as
an aid to proving it correct.  The information in a partial
correctness proof can be used to prove such
properties as mutual exclusion, freedom from deadlock,
and program termination.  Techniques for verifying
these properties are presented and illustrated by
application to the dining philosophers problem.
.A
Owicki, S.
Gries, D.
.K
structured multiprogramming correctness proofs, program
verification, concurrent processes, synchronization,
mutual exclusion, deadlock
.I 2866
.T
Proving Monitors
.W
Interesting scheduling and sequential properties
of monitors can be proved by using state variables
which record the monitor's history and by defining extended
proof rules for their wait and signal operations.
 These two techniques are defined, discussed, and applied
to examples to prove properties such as freedom
from indefinitely repeated overtaking or unnecessary waiting
upper bounds on queue lengths, and historical
behavior.
.A
Howard, J.H.
.K
monitors, correctness, proof rules, historical variables,
concurrency, scheduling, bounded buffer,
semaphores, alarm clock, disk head
.I 2867
.T
Modularization and Hierarchy in a Family of Operating Systems
.W
This paper describes the design philosophy
used in the construction of a family of operating
systems. It is shown that the concepts of module and
level do not coincide in a hierarchy of functions.
 Family members can share much software as a result
of the implementation of run-time modules at the
lowest system level.
.A
Habermann,A. N.
Flon, L.
Cooprider, L.
.K
incremental machine design, module,
data type, address space, virtual memory
.I 2868
.T
Reflections on an Operating System Design
.W
The main features of a general purpose multiaccess
operating system developed for the CDC 6400
at Berkeley are presented, and its good and bad points are
discussed as they appear in retrospect.  Distinctive
features of the design were the use of capabilities
for protection, and the organization of the system
into a sequence of layers, each building on the facilities
provided by earlier ones and protecting itself
from the malfunctions of later ones. There were serious
problems in maintaining the protection between
layers when levels were added to the memory hierarchy;
these problems are discussed and a new solution
is described.
.A
Lampson, B. W.
Sturgis, H. E.
.K
operating system, protection, capabilities,
layering domains, memory hierarchy, faults
.I 2869
.T
Security Kernel Validation in Practice
.W
A security kernel is a software and hardware
mechanism that enforces access controls within
a computer system. The correctness of a security kernel
on a PDP-11/45 is being proved.  This paper describes
the technique used to carry out the first step of the
proof: validating a formal specification of the
program with respect to a axioms for a secure system.
.A
Millen, J. K.
.K
validation, verification, correctness, security
kernel, formal specification, protection
.I 2870
.T
A Lattice Model of Secure Information Flow
.W
This paper investigates mechanisms that guarantee
secure information flow in a computer system.
These mechanisms are examined within a mathematical framework
suitable for formulating the requirements
of secure information flow among security classes. The
central component of the model is a lattice structure
derived from the security classes and justified by the semantics
of information flow.  The lattice properties
permit concise formulations of the security requirements
of different existing systems and facilitate
the construction of mechanisms that enforce security.
 The model provides a unifying view of all systems
that restrict information flow, enables a classification
of them according to security objectives, and
suggests some new approaches.  It also leads to the construction
of automatic program certification mechanisms
for verifying the secure flow of information through a program.
.A
Denning, D. E.
.K
protection, security, information flow, security
class, lattice, program certification
.I 2871
.T
Logical Analysis of Programs
.W
Most present systems for verification of computer
programs are incomplete in that intermediate
inductive assertions must be provided manually by the
user, termination is not proven, and incorrect
programs are not treated.  As a unified solution to
these problems, this paper suggests conducting a
logical analysis of programs by using invariants which
express what is actually occurring in the program.
 The first part of the paper is devoted to techniques
for the automatic generation of invariants.  The
second part provides criteria for using the invariants
to check simultaneously for correctness (including
termination) or incorrectness.  A third part examines
the implications of the approach for the automatic
diagnosis and correction of logical errors.
.A
Katz, S.
Manna, Z.
.K
logical analysis, invariants, program verification,
correctness, incorrectness, termination, automatic
debugging
.I 2872
.T
A Counterintuitive Example of Computer Paging (Corrigendum)
.A
Fagin, R.
.I 2873
.T
LG: A Language for Analytic Geometry
.W
A conversational programming language for analytic
geometry is described, together with some
aspects of its implementation.  The language allows
the flexible definition of geometric objects and
elements, computes their parameters, and displays the results.
It also provides the capability of specifying
a geometric figure via a collection of parameters and
displaying various loci corresponding to these
parameters. A third characteristic consists of the possibility
of using this language to design other
user oriented languages.  LG has been specifically designed
for use by nonprogrammers; it is easy to
learn and very close to the natural language used in geometry.
.A
Raymond, J.
.K
interactive programming, problem oriented languages,
computer graphics, interpreters, analytic
geometry
.I 2874
.T
A Comparative Evaluation of Versions of BASIC
.W
From its inception, The BASIC language has
grown in terms of its usage, scope of usage, and
its features.  This article compares ten of the current
versions of BASIC with each other, with two earlier
versions, and with the proposed standard for minimal
BASIC. The comparison is arranged by the features
of the versions and by computational comparison
of computation and times and processing costs.
.A
Lientz, B. P.
.K
BASIC, interpretive language summary
.I 2875
.T
Development of an International System
for Legal Protection of Computer Programs
.A
Smoot, O. R.
.K
copyright of software, patenting of
software, legal protection of software
.I 2876
.T
Intentional Resolution of Privacy Protection in Database Systems
.W
Traditionally, privacy protection in database
systems is understood to be the control over
what information a given user can get from a database.
 This paper is concerned with another, independent,
dimension of privacy protection, the control over what
a user is allowed to do with a piece of information
supplied to him by the database.  The ability to condition
the supply of information on its intended
use is called here "intentional resolution" of privacy
protection.  The practical importance of intentional
resolution is demonstrated by several examples, and its realization
is discussed.  It is shown that intentional
resolution can be achieved, but that it involves a radical
change from the traditional approach to the
process of user-database interaction.  In particular,
it appears to be necessary for the database to
impose a certain amount of control over the internal
behavior of users' programs which interact with
it.  A model for user-database interaction
which admits such a control is developed.
.A
Minsky, N.
.K
protection in database, protection in programming
languages, privacy, security, intentional resolution
of privacy, interaction with databases
.I 2877
.T
A Program Data Flow Analysis Procedure
.W
The global data relationships in a program
can be exposed and codified by the static analysis
methods described in this paper.  A procedure is given
which determines all the definitions which can
possibly "reach" each node of the control flow graph
of the program and all the definitions that are
"live" on each edge of the graph.  The procedure uses
an "interval" ordered edge listing data structure
and handles reducible and irreducible graphs indistinguishably.
.A
Allen, J. E.
Cocke, J.
.K
program optimization, data flow analysis,
flow graphs, algorithms, compilers
.I 2878
.T
Joining Policies in a Multipriority Multiclass Batch Computer System
.W
Consider a multipriority batch computer system
which users from several different classes may
join, its toll, service, and waiting charges.  Such a
system is formulated here as a semi-Markov decision
process, in which the aim of arriving users is to minimize
their expected loss.  The optimal joining
policy is one of arriving users who may join the system
at some of its queues is a control limit policy,
with a single control number for any possible queue
and the user's class; a newly arriving user will
join a queue that is not filled up to the control number
corresponding to this queue and the user's class.
 In this paper control numbers, as well as lower and upper
bounds for the control numbers and the capacities
of the system's queues, are derived.
.A
Babad, J. M.
Modiano, M. M.
.K
priority queues, semi-Markov process, price scheduling, operating system
.I 2879
.T
Computer Science as Empirical Inquiry: Symbols and Search
.A
Newell, A.
Simon, H. A.
.K
symbols, search, science, computer science, empirical,
Turing, artificial intelligence, intelligence,
list processing, cognition, heuristics, problem solving
.I 2880
.T
A Fast Division Technique for Constant Divisors
.W
A fast algorithm for division by constant divisors
is presented.  The method has proved very
useful implemented as microcode ona binary machine,
and can be adapted directly into hardware.  The
mathematical foundations of the algorithm are presented
as well as some performance measures.
.A
Artzy, E.
Hinds, J. A.
Saal, H. J.
.K
constant divisors, division algorithms,
bit addressable memory, microprogram
.I 2881
.T
A Counterintuitive Example of Computer Paging
.W
A counterexample is exhibited to a natural conjecture
concerning the optimal way to group records
into pages in the independent reference model of computer
paging (an organization is said to be optimal
if the "least recently used" miss ratio is minimized).
.A
Fagin, R.
.K
least recently used, most likely together, independent
reference model, storage organization, record
allocation
.I 2882
.T
A Stochastic Evaluation Model for Database
Organization in Data Retrieval Systems
.W
Experimental work in the valuation of large
scale data retrieval systems has been scarce due
to its difficulty and prohibitive cost. This paper
discusses a simulation model of a data retrieval
system which has the effect of significantly reducing
the cost of experimentation and enabling research
never attempted before.  The model is designed to estimate
the retrieval workload of alternative data
retrieval systems.  These data retrieval systems can
be organized under several database organizations,
including inverted list, threaded list, and cellular
list organizations and hybrid combinations of these
systems.  Effectiveness of the methodology is demonstrated
by using the model to study the effect of
database organizations in data retrieval systems.  In particular,
the impact of query complexity is analyzed.
.A
Siler, K. F.
.K
database architecture, database performance and
evaluation, invented list, threaded list, cellular
list, information retrieval, database organizations,
query complexity, stochastic model, Monte Carlo
simulation
.I 2883
.T
An Application of Heuristic Search Methods to Edge and Contour Detection
.W
This paper presents a method for detecting edges
and contours in noisy pictures.  The properties
of an edge are embedded in a figure of merit and the edge
detection problem becomes the problem of minimizing
the given figure of merit.  This problem can be represented
as a shortest path problem on a graph and
can be solved using well-known graph search algorithms.
 The relations between this representation of
the minimization problem and a dynamic programming approach
are discussed, showing that the graph search
method can lead to substantial improvements in computing
time.  Moreover, if heuristic search methods
are used, the computing time will depend on the amount
of noise in the picture.  Some experimental results
are given; these show how various information about the
shape of the contour of an object can be embedded
in the figure of merit, thus allowing the extraction
of contours from noisy picture and the separation
of touching objects.
.A
Martelli, A.
.K
picture processing, pattern recognition, edge
detection, contour detection, contour following,
optimization problems, dynamic programming, shortest
path, heuristic search methods, problem solving
methods
.I 2884
.T
Permutation Enumeration: Four New Permutation Algorithms
.W
Classical permutation enumeration algorithms encounter
special cases requiring additional computation
every nth permutation when generating the n! permutations
on n marks.  Four new algorithms have the attribute
that special cases occur every n(n-1)permutations.
Two of the algorithms produce the next permutation
with a single exchange of two marks.  The other two algorithms
infrequently exchange more than two marks,
but the rules for generating the next permutation are
very simple.  Performance tests which have counted
execution of assignment statements, comparisons, arithmetic
operations, and subscripted array references
have shown superiority of the new algorithms compared to
Boothroyd's implementation of M. B. Well's algorithm
and Ehrlich's implementation of the Johnson-Trotter algorithm.
.A
Ives, F. M.
.K
permutations, loop-free algorithms
.I 2885
.T
On Self-Organizing Sequential Search Heuristics
.W
This paper examines a class of heuristics for
maintaining a sequential list in approximately
optimal order with respect to the average time required
to search for a specified element, assuming that
each element is searched for with a fixed probability
independent of previous searches performed.  The
"move to front" and "transposition" heuristics are shown
to be optimal to within a constant factor, and
the transposition rule is shown to be the more efficient
of the two. Empirical evidence suggests that
transposition is in fact optimal for any distribution of search probabilities.
.A
Rivest, R.
.K
searching, self-organizing, list-processing, heuristics
.I 2886
.T
Semantic Evaluation from Left to Right
.W
This paper describes attribute grammars and their
use for the definition of programming languages
and compilers; a formal definition of attribute grammars
and a discussion of some of its important aspects
are included. The paper concentrates on the evaluation
of semantic attributes in a few passes from left
to right over the derivation tree of a program.  A
condition for an attribute grammar is given which
assures that the semantics of any program can be evaluated
in a single pass over the derivation tree,
and an algorithm is discussed which decides how many
passes from left to right are in general necessary,
given the attribute grammar. These notions are explained
in terms of an example grammar which describes
the scope rules of Algol 60.  Practical questions, such
as the relative efficiency of different evaluation
schemes, and the ease of adapting the attribute grammar
of a given programming language to the left-to-right
evaluation scheme are discussed.
.A
Bochmann, G. V.
.K
attribute grammars, semantics of programming languages,
semantic attributes, left-to-right parsing,
multipass compilers, semantic evaluation, semantic conditions
.I 2887
.T
A Study of Errors, Error-Proneness, and Error Diagnosis in Cobol
.W
This paper provides data on Cobol error frequency
for correction of errors in student-oriented
compilers, improvement of teaching, and changes in programming
language.  Cobol was studied because of
economic importance, widespread usage, possible error-including
design, and lack of research.  The types
of errors were identified in a pilot study; then, using
the 132 error types found, 1,777 errors were
classified in 1,4000 runs of 73 Cobol students.  Error
density was high: 20 percent of the types contained
80 percent of the total frequency, which implies high
potential effectiveness for software based correction
of Cobol.  Surprisingly, only four high-frequency errors
were error-prone, which implies minimal error
inducing design. 80 percent of Cobol misspellings were classifiable
in the four error categories of previous
researchers, which implies that Cobol misspellings
are correctable by existent algorithms.  Reserved
word usage was not error-prone, which implies minimal
interference with usage of reserved words.  Over
80 percent of error diagnosis was found to be inaccurate.
 Such feedback is not optimal for users, particularly
for the learning user of Cobol.
.A
Litecky, C. R.
Davis, G. B.
.K
errors in programming, error correction, Cobol, programming
language errors, error analysis, diagnostics,
error-proneness, error frequency, spelling errors, syntactic
errors, learning of programming, teaching
of programming
.I 2888
.T
Information Reference Coding
.W
Items in business systems have to be identified
by reference codes, which can later be used
as data codes and file keys in an associated data processing
system.  In business systems associated
with large collections of integrated files (database)
it is vital to assign codes in a methodical way
so as to control future extension and changes while maintaining
correct program action. The principles
of methodical coding are discussed, and the way in
which logical connections between data items must
be reflected in the reference code framework is shown
through a set-theoretic information model.
.A
Florentin, J. J.
.K
data, file, reference code, systems
analysis, information modeling, database
.I 2889
.T
Performance of Height-Balanced Trees
.W
This paper presents the results of simulations
that investigate the performance of height-balanced
(HB[k]) trees.  It is shown that the only statistic
of HB[1] trees (AVL trees) that is a function of
the size of the tree is the time to search for an item
in the tree.  For sufficiently large trees, the
execution times of all procedures for maintaining HB[1]
trees are independent of the size of the tree.
 In particular, an average of .465 restructures are required
per insertion, with an average of 2.78 nodes
revisited to restore the HB[1] property; an average of
.A
Karlton, P. L.
Fuller, S. H.
Scroggs, R. E.
Kaehler, E. B.
.K
HB[k] trees, balanced trees, AVL trees,
information storage and retrieval, searching
.I 2890
.T
On Quadratic Adaptive Routing Algorithms
.W
Two analytic models of a store-and-forward communications
network are constructed, one to find
the optimal message routing and the other to illustrate
the equilibrium (stationary state) maintained
by an adaptive routing algorithm.  These models show that
adaptive routing does not satisfy the necessary
conditions for an optimal routing,  Adaptive routing tends
to overuse the direct path and underuse alternate
routes because it does not consider the impact of its
current routing decision on the future state of
the network.  The form of the optimality conditions suggests
that a modification of the adaptive algorithm
will result in optimality.  The modification requires
the substitution of a quadratic bias term instead
of a linear one in the routing table maintained at each
network node.  Simulation results are presented
which confirm the theoretical analysis for a simple network.
.A
Agnew, C. E.
.K
routing algorithms, adaptive routing, quadratic routing,
alternate routing, store-and-forward network,
distributed network, computer network, message switching
.I 2891
.T
An Anomaly in Disk Scheduling: A Comparison of
FCFS and SSTF Seek Scheduling Using an Empirical
Model for Disk Accesses
.W
A model for disk accesses based on published
measurements is developed.  The model is used
to show that under highly probable conditions, FCFS
seek scheduling is superior to SSTF scheduling in
the sense of having a lower mean queue length.  A simple
example of an arrival sequence illustration
this anomaly is presented.
.A
Wilhelm, N. C.
.K
disks, disk scheduling, seek scheduling
.I 2892
.T
A Study of Line Overhead in the Arpanet
.W
The form, extent, and effect of the communication line
overhead in the ARPANET are considered.
 The source of this over head is separated into various
levels of protocol hierarchy and the characteristics
of each level are summarized.  Then the line efficiency
for various models of system use is studied.
 Some measurements of line efficiency for the ARPANET are
presented and by extrapolation these measurements
are used to anticipate overhead in a heavily loaded network.
Similar results are derived for a recently
proposed network protocol and compared with those for the current system.
.A
Kleinrock, L.
Naylor, W. E.
Opderbeck, H.
.K
ARPANET, computer communication networks, interprocess
communication, measurement, packet switching,
performance evaluation and efficiency, resource sharing
.I 2893
.T
Computers as an Innovation in American Local Governments
.W
Computers and electronic data processing are
a major technological innovation in the operations
of American local government. This paper establishes that
there is substantial variation among the larger
local governments in the rate at which they adopt computer
technology, in the level of financial support
they provide for EDP, and in the extensiveness and sophistication
of their automated applications.  The
central question addressed is: What might explain the
differences between governments in the extent to
which they adopt and use computers?  Hypotheses are
tested for several streams of explanatory factors,
using data from more than 500 city and county governments.
 The findings identify certain local government
milieus which are particularly conducive to higher levels
of computer innovation.  Somewhat unexpected
findings reveal the significant impact of the distribution
of control over EDP decisions and the dominant
political values within the government. Other important
factors include the measured need for computer
applications and the presence of external funding support
for computing.  Finally, the paper suggests
a framework for identifying the key determinants
of other technological innovations.
.A
Danziger, J. N.
Dutton, W. H.
.K
innovation, technological innovation, computer utilization,
computer adoption, American local government,
city government computers, county government computers.
.I 2894
.T
A Methodology for Interactive Computer Service Measurement
.W
A measurement methodology applicable to in teractive
computer service is described.  Its primary
purpose is to enable external, user-oriented assessment
of computer performance, instead of the more
frequently used in ternal system measurement techniques.
 The NBS Network Measurement System is employed
as the external measurement tool.  Example data have
been collected and analyzed.  A demonstration of
the methodology, leading to a pragmatic figure-of-merit
evaluation of results, is included.
.A
Adrams, M. D.
.K
in teractive system, computer service, measurement,
performance, external measurement, methodology,
measurement model,network measurement system, measures, figure-of-merit.
.I 2895
.T
A Language for Formal Problem Specification
.W
A language for specifying the in tended behavior
of communicating parallel processes is described.
 The specifications are constrain ts on the order in which
events of a computation can occur.  The language
is used to write specifications of the readers/writers
problem and the writer priority of the second
readers/writers problem.
.A
Greif, I.
.K
formal specifications,program correctness, parallel
processing, synchronization, readers/writers
problem
.I 2896
.T
An Exercise in Proving Parallel Programs Correct
.W
A parallel program, Dijkstra's on-the-fly garbage
collector, is proved correct using a proof
method developed by Owicki.  The fine degree of in terleaving
in this program makes it especially difficult
to understand, and complicates the proof greatly.  Difficulties
with proving such parallel programs correct
are discussed.
.A
Gries, D.
.K
garbage collection, multiprocessing, program
correctness for multiprocessing tasks
.I 2897
.T
A Case Study of a New Code Generation Technique for Compilers
.W
Recent developments in optimizing techniques
have allowed a new design for compilers to emerge.
 Such a compiler translates the parsed source code into
lower level code by a sequence of steps.  Each
step expands higher level statements into blocks of
lower level code and then performs optimizations
on the result.  Each statement has only one possible
expansion-the task of tailoring this code to take
advantage of any special cases is done by the optimizations.
 This paper provides evidence that this
strategy can indeed result in good object code.  The
traditionally difficult PL/I concatenate statement
was investigated as a detailed example.  A set of fairly
simple optimizations was identified which allow
the compiler to produce good code. More elaborate optimizations
can further improve the object code.
 For most contexts of the concatenate statement, the code
produced by a compiler using the expansion-optimization
strategy described above compares favorably with the
code produced by a conventional PL/I optimizing
compiler.
.A
Carter, J. L.
.K
compiler structure, optimizing compiler, code
generation, PL/I compiler, concatenation, program
optimization, optimization techniques, data flow analysis
.I 2898
.T
A Conceptual Framework for a Nonprocedural Programming Language
.W
A sequential programming language forces the
programmer to prescribe explicitly the order in
which the operations in his program have to be executed,
even if the order is not relevant to the solution
of his problem.  The requirement to indicate irrelevant
sequencing can be removed if the language provides
facilities for specifying a task in a nonprocedural
manner.  In general, a program specified in this
way will allow concurrent evaluation.  This paper describes
a conceptual framework for a high level programming
language providing both nonprocedural and sequential
facilities.  Within a program, nonprocedural and
sequential program modules may be nested freely.
.A
Kessels, J. L. W.
.K
parallel programming, descriptive programming,
nonprocedural programming, definitional language,
data flow programming, applicative programming
.I 2899
.T
A Survey of Computer Science Offerings In Small Liberal Arts Colleges.
.W
Recent curricular development in computer science
together with student in terest in pursuing
topics in computer science beyond the usual programming
courses have encouraged small liberal arts colleges
to expand their offerings.  This paper summarizes the
results of a survey taken to determine the type
of computer science programs being offered in these
colleges.  The results indicate that over half of
these colleges either have no computer science
program or offer only programming courses.
.A
Lopez, A. A.
Raymond, R.
Tardiff, R.
.K
computer science, education, curricula, small colleges
.I 2900
.T
Some Theorems to Aid in Solving the File Allocation Problem
.W
The file allocation problem-i.e. the problem
of finding the optimal set of network sites at
which to locate copies of a file-is known to be, in general,
polynomial complete.  Heuristics and other
aids to finding optimal, or near-optimal, solutions are
therefore much needed.  In this paper we present
three theorems which can be applied a priori to indicate
that certain sites should (or should not) be
included in an optimal allocation.
.A
Grapa, E.
Belford, G. G.
.K
File allocation, computer networks, distributed data management
.I 2901
.T
An Encoding Method for Multifield Sorting and Indexing
.W
Sequences of character strings with an order
relation imposed between sequences are considered.
 An encoding scheme is described which produces a single,
order-preserving string from a sequence of
strings.  The original sequence can be recovered from
the encoded string, and one sequence of strings
precedes another if and only if the encoding of the first
precedes the encoding of the second.  The strings
may be variable length, without a maximum length restriction,
and no symbols need be reserved for control
purposes.  Hence any symbol may occur in any string.  The
scheme is useful for multifield sorting, multifield
indexing, and other applications where ordering
on more than one field is important.
.A
Blasgen, M. W.
Casey, R. G.
Eswaran, K. P.
.K
Sorting multifield indexes, lexicographic order, searching, encoding
.I 2902
.T
Dynamic Memory Allocation in Computer Simulation
.W
This paper investigates the performance of
35 dynamic memory allocation algorithms when used
to service simulation programs as represented by 18
test cases.  Algorithm performance was measured in
terms of processing time, memory usage, and external memory
fragmentation.  Algorithms main taining separate
free space lists for each size of memory block used
tended to perform quite well compared with other
algorithms.  Simple algorithms operating on memory ordered
lists (without any free list) performed surprisingly
well.  Algorithms employing power-of-two block sizes
had favorable processing requirements but generally
unfavorable memory usage.  Algorithms employing LIFO, FIFO,
or memory ordered free lists generally performed
poorly compared with others.
.A
Nielsen, N. R.
.K
algorithm performance,dynamic memory allocation, dynamic
memory management, dynamic storage allocation,
garbage collection, list processing, memory allocation,
memory management, programming techniques, simulation,
simulation memory management, simulation techniques,
space allocation, storage allocation
.I 2903
.T
Improving Programs by the Introduction of Recursion
.W
A new technique of program transformation,
called "recursion in troduction," is described and
applied to two algorithms which solve pattern matching problems.
 By using recursion in troduction, algorithms
which manipulate a stack are first translated into
recursive algorithms in which no stack operations
occur.  These algorithms are then subjected to a second
transformation, a method of recursion elimination
called "tabulation," to produce programs with a very
efficient running time.  In particular, it is shown
how the fast linear pattern matching algorithm of Knuth,
Morris, and Pratt can be derived in a few steps
from a simple nonlinear stack algorithm.
.A
Bird, R. S.
.K
program transformation, optimization of programs,
recursion elimination, pattern matching algorithms,
stacks, computational induction
.I 2904
.T
An Algorithm for Reduction of Operator Strength
.W
A simple algorithm which uses an indexed temporary
table to perform reduction of operator strength
in strongly connected regions is presented.  Several extensions,
including linear function test replacement,
are discussed.  These algorithms should fit well into an
integrated package of local optimization algorithms.
.A
Cocke, J.
.K
compilers, optimization of compiled code, program analysis,
operator strength reduction, test replacement,
strongly connected region
.I 2905
.T
Perfect Hashing Functions: A Single
Probe Retrieving Method for Static Sets
.W
A refinement of hashing which allows retrieval
of an item in a static table with a single probe
is considered.  Given a set I of identifiers, two methods
are presented for building, in a mechanical
way, perfect hashing functions, i.e. functions transforming
the elements of I into unique addresses.
 The first method, the "quotient reduction" method, is
shown to be complete in the sense that for every
set I the smallest table in which the elements of I
can be stored and from which they can be retrieved
by using a perfect hashing function constructed by this
method can be found.  However, for nonuniformly
distributed sets, this method can give rather sparse tables.
 The second method, the "remainder reduction"
method, is not complete in the above sense, but it seems
to give minimal (or almost minimal) tables for
every kind of set.  The two techniques are applicable
directly to small sets.  Some methods to extend
these results to larger sets are also presented.  A rough
comparison with ordinary hashing is given which
shows that this method can be used conveniently
in several practical applications.
.A
Sprugnoli, R.
.K
hashing, hashing methods, hash coding, direct addressing,
identifier-to-address transformations,
perfect hashing functions, perfect hash coding, reduction, scatter storage
.I 2906
.T
A Very High Level Programming Language for Data Processing Applications
.W
Application development today is too labor-in tensive.
 In recent years, very high-level languages
have been increasingly explored as a solution to this
problem.  The Business Definition Language (BDL)
is such a language, one aimed at business data processing
problems.  The concepts in BDL mimic those
which have evolved through the years in businesses using
manual methods.  This results in three different
sublanguages or components: one for defining the business
forms, one for describing the business organization,
and one for writing calculations.
.A
Hammer, M.
owe, W. G.
Kruskal, V. J.
Wladawsky, I.
.K
very high level language, nonprocedural language,
data flow language, business application, business
data processing, structured programming, modular programming,
format specification, and design methodology
.I 2907
.T
The Optimal Approach to Recursive Programs
.W
The classical fixed poin t approach toward recursive
programs suggests choosing the "least defined
fixed poin t" as the most appropriate solution to a recursive
program.  A new approach is described which
in troduction an " optimal fixed point," which, in contrast
to the least defined fixed poin t, embodies the
maximal amount of valuable information embedded in the
program.  The practical implications of this approach
are discussed and techniques for proving properties
of optimal fixed poin t are given.  The presentation
is informal, with emphasis on examples.
.A
Manna, Z.
Shamir, A.
.K
recursive programs, fixed poin ts, least fixedpoints,
optimal fixed poin ts, proof techniques
.I 2908
.T
A Note On Reflection-Free Permutation Enumeration
.A
Roy, M. K.
.K
permutations, reflection-free generation
.I 2909
.T
What Can We Do about the Unnecessary Diversity
of Notation for Syntactic Definitions?
.A
Wirth, N.
.K
syntactic description language, extended BNF
.I 2910
.T
Equivalence of Hough Curve Detection to Template Matching
.A
Stockman, G. C.
.K
picture processing, pattern recognition, curve
detection, Hough transformation, template matching
.I 2911
.T
Anomalous Behavior of the Fifty-Percent
Rule in Dynamic Memory Allocation
.W
This paper reports simulation data showing
that, in dynamic memory allocation, the average
free-to-allocated-block ratio can differ considerably
and in both directions from the predictions of
the 50 percent rule.  A new derivation is given, and it
is shown that previous derivations make an assumption
that may be violated frequently.  On the basis of the simulation
data and the derivation, it is hypothesized
that the anomalous behavior results from the combined
effects of systematic placement and the statistics
of the release process.  Additional simulations support
this hypothesis.  Systematic placement, which
refers to the natural convention of always allocating
storage requests against the same end of the free
block selected by the allocation strategy, tends to
order blocks within contiguous groups according to
their allocation time.  The degree of anomalous behavior
depends on the extent to which allocated blocks
are released in the order of their allocation.  For
non-Markovian release processes, the extent of the
correlation between allocation order and release order
varies approximately inversely with the coefficient
of variation of the memory residence time distribution.
 The simulations show that allocation efficiency
depends strongly on the residence time distribution; efficiency
decreases as the distribution's coefficient
of variation increases.  Some practical implications are briefly discussed.
.A
Shore, J. E.
.K
dynamic memory allocation, storage fragmentation,
fifty-percent rule, first-fit, simulation
.I 2912
.T
Concurrent Reading and Writing
.W
The problem of sharing data among asynchronous
process is considered.  It is assumed that only
one process at a time can modify the data, but concurrent
reading and writing is permitted.  Two general
theorems are proved, and some algorithms are presented
to illustrate their use.  These include a solution
to the general problem in which a read is repeated if
it might have obtained an incorrect result, and
two techniques for transmitting messages between processes.
 These solutions do not assume any synchronizing
mechanism other than data which can be written
by one process and read by other processes.
.A
Lamport, L.
.K
asynchronous multiprocessing, multiprocess synchronization,
readers/writers problem, shared data
.I 2913
.T
The Aliasing Problem in Computer-Generated Shaded Images
.W
Certain defects, such as jagged edges and
disappearing detail, have long been an annoyance
in digitally generated shaded images.  Although increasing
the resolution or defocusing the display can
attenuate them, an understanding of these defects leads
to more effective methods.  This paper explains
the observed defects in terms of the aliasing phenomenon
inherent in sampled signals and discusses prefiltering
as a recognized cure.  A method for evaluating filters
is presented, the application of prefiltering
to hidden-surface algorithms is discussed, and an implementation
of a filtering tiler is shown accompanied
by examples of its effectiveness.
.A
Crow, F. C.
.K
aliasing, computer graphics, convolutional
filtering, hidden-surface removal, sampling
.I 2914
.T
Use of the LRU Stack Depth Distribution
for Simulation of Paging Behavior
.W
Two families of probability distributions were
needed for use by a virtual memory simulation
model: headway between page fault distributions, and
working set size distributions.  All members of
both families can be derived from the LRU stack depth distribution.
 Simple expressions for the computation
of both kinds of distributions are given.  Finally, examples
are given of both families of distributions
as computed from a published stack depth distribution.
.A
Turner, R.
Strecker, B.
.K
virtual memory, paging, LRU stack, working set, headway
between page faults, computer system simulation
.I 2915
.T
Considerations for Future Programming Language Standards Activities
.W
This paper reviews the current state of programming
language standards activities with respect
to the anomalies which exist between the various published
and proposed standards for Fortran, Cobol,
PL/I, and Basic.  Proposals are made for the inclusion
of formalisms within future standards and the
extension of the standards to include additional items
such as error conditions and documentation.
.A
Lee, J. A. N.
.K
programming languages, standards, formalisms,
formal descriptions, Fortran, Cobol, PL/I, Basic,
Vienna Definition Language (VDL)
.I 2916
.T
A Fast String Searching Algorithm
.W
An algorithm is presented that searches for
the location, "i," of the first occurrence of a
character string, "pat," in another string, "string."
 During the search operation, the characters of
pat are matched starting with the last character of
pat.  The information gained by starting the match
at the end of the pattern often allows the algorithm
to proceed in large jumps through the text being
searched.  Thus the algorithm has the unusual property that,
in most cases, not all of the first i characters
of string are inspected.  The number of characters actually
inspected (on the average) decreases as a
function of the length of pat.  For a random English
pattern of length 5, the algorithm will typically
inspect i/4 characters of string before finding a match at
i.  Furthermore, the algorithm has been implemented
so that (on the average) fewer than i+patlen machine
instructions are executed.  These conclusions are
supported with empirical evidence and a theoretical
analysis of the average behavior of the algorithm.
 The worst case behavior of the algorithm is linear in
i+patlen, assuming the availability of array space
for tables linear in patlen plus the size of the alphabet.
.A
Boyer, R. S.
.K
bibliographic search, computational complexity,
information retrieval, linear time bound, pattern
matching, text editing
.I 2917
.T
SITAR: An Interactive Text Processing
System for Small Computers (Corrigendum)
.A
Schneider, B. R. Jr.
Watts, R. M.
.I 2918
.T
Multiprocessor Memory Organization and Memory Interference
.W
The structure of shared memory in a multiprocessor
computer system is examined with particular
attention to nonin terleaved memory.  Alternative memory
organizations are compared and it is shown that
a home memory organization, in which each processor
is associated with one or more memories in which
its address space is concentrated, is quite effective in
reducing memory in terference.  Home memory organization
is shown to be particularly suited to certain specialized
computation problems as well as to possess
advantages in terms of in terference and reliability for
general purpose computation.  Results for in terleaved
memory are drawn from previous work and are used for
comparison.  Trace-driven simulations are used to
verify the conclusions of the analysis.
.A
Smith, A. J.
.K
memory in terference, interleaving, multiprocessing,
trace-driven simulation, queueing theory, shared
memory
.I 2919
.T
The Programmer's Workbench-A Machine for Software Development
.W
On almost all software development projects the
assumption is made that the program development
function will be done on the same machine on which the
eventual system will run.  It is only when this
production machine is unavailable or when its programming
environment is totally inadequate that alternatives
are considered.  In this paper it is suggested that
there are many other situations where it would be
advantageous to separate the program development and
main tenance function onto a specialized computer
which is dedicated to that purpose.  Such a computer
is here called a Programmer's Workbench.  The four
basic sections of the paper in troduce the subject,outline
the general concept, discuss areas where such
an approach may prove beneficial, and describe
an operational system utilizing this concept.
.A
Ivie, E. L.
.K
computer configurations, computer networks, software
development, software engineering, software
main tenance, UNIX
.I 2920
.T
Game Interpretation of the Deadlock Avoidance Problem
.W
The deadlock avoidance problem may be defined
informally as the determination, from some a
priori information about the processes, resources, operating
system, etc., of the "safe situations" which
may be realized without endangering the smooth running
of the system.  When each process specifies its
future needs by a flowchart of need-defined steps, a global
approach to the phenomenon and its in terpretation
as a game between the operating system and the processes
allows formalization of risk and safety concepts.
 The bipartite graph representation of this game may
then be used to construct explicitly the set of safe
states and to study their properties.
.A
Devillers, R.
.K
operating system, multiprogramming, time-sharing,
resource allocation, deadlock, in terlock, deadly
embrace, deadlock avoidance, flowchart
.I 2921
.T
Regular Right Part Grammars and Their Parsers
.W
This paper in troduces an alternative to context-free
grammars called regular right part (RRP)
grammars, which resemble PASCAL syntax diagrams.  Formally,
RRP grammars have production right parts,
which are nondeterministic finite state machines (FSMs),
and, as a special case, regular expressions,
since these can be converted to FSMs.  RRP grammars
describe the syntax of programming languages more
concisely and more understandably than is possible with
CF grammars.  Also in troduced is a class of parsers,
RRP LR(m, k) parsers, which includes the CF LR(k) parsers
and provides the same advantages.  Informally,
an RRP LR(m, k) parser can determine the right end of
each handle by considering at most k symbols to
the right of the handle and the left end, after the
right end has been found, by considering at most
m symbols to the left of the handle.  A mechanism for
determining the left end is required because there
is no bound on the length of the handle.
.A
LaLonde, W. R.
.K
finite state machines (automata), regular expressions,
syntax diagrams,LR(k) grammars, parser construction,
parsing, programming languages, language generation,
formal definition, compilers, translators, scanners
.I 2922
.T
Two-Level Control Structure for Nondeterministic Programming
.W
The basic ideas of nondeterministic programming
are critically reconsidered to single out a
proper attitude and programming style for language allowing
direct control of nondeterministic features.
 The proposed attitude aims at retaining the purity of
the nondeterministic formulation of search processes
on one level (the attempt level), deferring the coordination
of problem solving efforts to another (the
choice level).  The feasibility of recognizing these two
levels is discussed, stressing that the structure
to be managed at the choice level is a free of contexts.
 The leaves are computational environments,
each holding an alternative under inspection, while
the other nodes are associated with choice poin ts.
 According to the proposed programming style, a generative
function is associated with each choice poin t,
which expresses the desired choice strategy. The main
advantage on this approach is the localization
of the search strategies: Each nonterminal node of the
tree keeps track of the state of the computation
as it was when the choice poin t was last interrogated,
holding at the same time the strategy to coordinate
the available alternatives.  Examples are given in
term of ND-Lisp, an extension of Lisp designed and
implemented according to these guidelines.
.A
Montangero, C.
Pacini, G.
Turini, F.
.K
nondeterministic programming, artificial in telligence,
control structures, backtracking, search
strategy planning, context tree
.I 2923
.T
High-Level Data Flow Analysis
.W
In contrast to the predominant use of low-level
in termediate text, high-level data flow analysis
deals with programs essentially at source level and
exploits the control flow information implicit in
the parse tree.  The need for high-level flow analysis
arises from several aspects of recent work on
advanced methods of program certification and optimization.
 This paper proposes a simple general method
of high-level data flow analysis that allows free use
of escape and jump statements, avoids large graphs
when compiling large programs, facilitates updating of
data flow information to reflect program changes,
and derives new global information helpful in solving
many familiar global flow analysis problems.  An
illustrative application to live variable analysis is presented.
 Many of the graphs involved are constructed
and analyzed before any programs are compiled, thus avoiding
certain costs that low-level methods incur
repeatedly at compile time.
.A
Rosen, B. K.
.K
data flow analysis, high-level language, control
flow graph, structured programming, escapes, exits,
jumps, goto statements
.I 2924
.T
An Interactive Computer Graphics Approach to Surface Representation
.W
An in teractive computer graphics method has been
developed for the rapid generation of arbitrary
shaped three-dimensional surfaces.  The method is a synthesis
of spline theory and algorithms, an in teractive
means for man-machine communication, and software for
static or dynamic graphics display.  The basic
technique employed is a modified lofting method on
which sectional curves are represented by uniform
B-splines and the surface is in terpolated between sections
by Cardinal splines.  Among the features of
this method are algorithms which enable in teractive
modification of the B-spline representation of the
sectional curves.  At all stages of the process, the
spatial information is graphically displayed to
the user.  Complex surfaces can be created by the combination
of a number of shapes that have been separately
generated and automatically joined.  The system has been
successfully in terfaced to a variety of analytical
routines for structural, medical and graphical applications.
.A
Wu, Sheng-Chuan
Abel, J. F.
Greenberg, D. P.
.K
computer graphics, three-dimensional surface representation,
splines, lofting,finite element input
methods
.I 2925
.T
Optimal Surface Reconstruction from Planar Contours
.W
In many scientific and technical endeavors,
a three-dimensional solid must be reconstructed
from serial sections, either to aid in the comprehension
of the object's structure or to facilitate its
automatic manipulation and analysis.  This paper presents
a general solution to the problem of constructing
a surface over a set of cross-sectional contours.
This surface, to be composed of triangular tiles,
is constructed by separately determining an optimal
surface between each pair of consecutive contours.
 Determining such a surface is reduced to the problem
of finding certain minimum cost cycles in a directed
toroidal graph.  A new fast algorithm for finding such
cycles is utilized.  Also developed is a closed-form
expression, in term of the number of contour poin ts, for
an upper bound on the number of operations required
to execute the algorithm.  An illustrated example which
involves the construction of a minimum area surface
describing a human head is included.
.A
Fuchs, H.
Kedem,Z. M.
Uselton, S. P.
.K
surface reconstruction, contour data, serial sections,
three-dimensional computer graphics, minimum
cost paths, continuous tone displays
.I 2926
.T
Pagination of B*-Trees with Variable-Length Records
.W
A strategy is presented for pagination of B*-trees
with variable-length records.  If records
of each length are uniformly distributed within the
file, and if a wide distribution of record lengths
exists within the file, then this strategy results in shallow
trees with fast access times.  The performance
of this strategy in an application is presented, compared
with that of another strategy, and analyzed.
.A
McCreight, E. M.
.K
B-tree, index, database, tree storage structure, searching
.I 2927
.T
Some New Upper Bounds on the Generation of Prime Numbers
.W
Given an integer N, what is the computational
complexity of finding all the primes less than
N?  A modified sieve of Eratosthenes using doubly linked
lists yields an algorithm of O(N) arithmetic
complexity.  This upper bound is shown to be equivalent
to the theoretical lower bound for sieve methods
without preprocessing.  Use of preprocessing techniques
involving space-time and additive-multiplicative
tradeoffs reduces this upper bound to O(N/log logN)
and the bit complexity to O(N logN log log logN).
 A storage requirement is described using O(N logN/log logN) bits as well.
.A
Mairson, H. G.
.K
computational complexity, sieve, prime number generation,
number theory, linked list, preprocessing,
balancing
.I 2928
.T
Hardware Estimation of a Process' Primary Memory Requirements
.W
A minor hardware extension to the Honeywell
6180 processor is demonstrated to allow the primary
memory requirements of a process in Multics to be approximated.
 The additional hardware required for
this estimate to be computed consists of a program accessible
register containing the miss rate of the
associative memory used for page table words.  This
primary memory requirement estimate was employed
in an experimental version of Multics to control the
level of multiprogramming in the system and to bill
for memory usage.  The resulting system's tuning parameters
display configuration insensitivity, and
it is conjectured that the system would also track shifts
in the referencing characteristics of its workload
and keep the system in tune.
.A
Giffor, D. K.
.K
primary memory requirement, virtual memory, level
of multiprogramming, associative memory, working
set, resource allocation, LRU stack model, referencing characteristics
.I 2929
.T
An Analysis of Inline Substitution for a Structured Programming Language
.W
An optimization technique known as inline substitution
is analyzed.  The optimization consists
of replacing a procedure invocation by a modified copy
of the procedure body.  The general problem of
using inline substitution to minimize execution time
subject to size constrain ts is formulated, and an
approximate algorithmic solution is proposed.  The algorithm
depends on run-time statistics about the
program to be optimized.  Preliminary results for the
CLU structured programming language indicate that,
in programs with a low degree of recursion, over 90
percent of all procedure calls can be eliminated,
with little increase in the size of compiled code and a
small savings in execution time.  Other conclusions
based on these results are also presented.
.A
Scheifler, R. W.
.K
inline substitution, open coding, open compilation,
program optimization, compilers, structured
programming languages, run-time statistics
.I 2930
.T
The GRE Advanced Test in Computer Science
.W
This report describes the Advanced Test in
Computer Science which was recently in troduced in
the Graduate Record Examination Program.  The GRE program
is described in general, and, the events leading
to the establishment of the Advanced Computer Science
Test are discussed.  Content specifications and
their rationale are given.  A set of sample questions is included.
.A
Austing, R. H.
.K
education, computer science, graduate school
admissions, test development examinations
.I 2931
.T
Logic and Programming Languages
.W
Logic has been long in terested in whether answers
to certain questions are computable in principle,
since the outcome puts bounds on the possibilities of
formalization.  More recently, precise comparisons
in the efficiency of decision methods have become available
through the developments in complexity theory.
 These, however, are applications to logic, and a big question
is whether methods of logic have significance
in the other direction for the more applied parts of
computability theory.  Programming languages offer
an obvious opportunity as their syntactic formalization
is well advanced; however, the semantical theory
can hardly be said to be complete.  Though we have
many examples, we have still to give wide-ranging
mathematical answers to these queries:  What is a machine?
 What is a computable process?  How (or how
well) does a machine simulate a process?  Programs naturally
enter in giving descriptions of processes.
 The definition of the precise meaning of a program
then requires us to explain what are the objects
of computation (in a way, the statics of the problem)
and how they are to be transformed (the dynamics).
 So far the theories of automata and of nets, though
most in teresting for dynamics, have formalized only
a portion of the field, and there has been perhaps too
much concentration on the finite-state and algebraic
aspects.  It would seem that the understanding of higher-level
program features involves us with infinite
objects and forces us to pass through several levels
of explanation to go from the conceptual ideas to
the final simulation on a real machine.  These levels
can be made mathematically exact if we can find
the right abstractions to represent the necessary structures.
 The experience of many independent workers
with the method of data types as lattices (or partial
orderings) under an information content ordering,
and with their continuous mappings, has demonstrated the
flexibility of this approach in providing definitions
and proofs, which are clean and without undue dependence
on implementations.  Nevertheless much remains
to be done in showing how abstract conceptualizations
can (or cannot) be actualized before we can say
we have a unified theory.
.A
Scott, D. S.
.K
logic, programming languages, automata, denotational
semantics, a-calculus models, computability,
partial functions, approximation, function spaces
.I 2932
.T
Complexity of Computations
.W
The framework for research in the theory of complexity
of computations is described, emphasizing
the in terrelation between seemingly diverse problems
and methods.  Illustrative examples of practical
and theoretical significance are given.  Directions
for new research are discussed.
.A
Rabin, M. O.
.K
complexity of computations, algebraic complexity,
in tractable problems, probabilistic algorithms
.I 2933
.T
Another Advantage of Keyword Notation for
Parameter Communication with Subprograms
.A
Francez, N.
.K
Keyword notation, positional notation, parameters,
transmission, subprograms, readability, call
by value, call by reference, call by name, compile-time errors
.I 2934
.T
Comment on Computing the k Shortest Paths in a Graph
.A
Lawler, E. L.
.K
graph, network, shortest path, algorithm, ranking
.I 2935
.T
Production and Employment of Ph.D.'s
in Computer Science-1976 (Corrigendum)
.A
Taulbee, O. E.
Conte, S. D.
.I 2936
.T
An Efficient Data Structure for the Simulation Event Set
.W
Recently algorithms have been presented for the
realization of event scheduling routines suitable
for general purpose discrete event simulation systems.
 Several exhibited a performance superior to that
of commonly used simple linked list algorithms.  In this
paper a new event scheduling algorithm is presented
which improves on two aspects of the best of the previously
published algorithms.  First, the new algorithm's
performance is quite insensitive to skewed distributions,
and second, its worst-case complexity is O(
n), where n is the number of events in the set.  Furthermore,
tests conducted to estimate the average
complexity showed it to be nearly independent of n.
.A
Franta, W. R.
Maly, K.
.K
simulation, time flow mechanisms, event
scanning mechanisms, multilinked lists
.I 2937
.T
An Experimental Evaluation of Data Type Conventions
.W
The language in which programs are written
can have a substantial effect on the reliability
of the resulting programs.  This paper discusses an experiment
that compares the programming reliability
of subjects using a statically typed language and a "typeless"
language.  Analysis of the number of errors
and the number of runs containing errors shows that, at
least in one environment, the use of a statically
typed language can increase programming reliability.
Detailed analysis of the errors made by the subjects
in programming solutions to reasonably small problems
shows that the subjects had difficulty manipulating
the representation of data.
.A
Gannon, J. D.
.K
data types, experimentation, language
design, redundancy, reliable software
.I 2938
.T
Toward a Discipline of Real-Time Programming
.W
Programming is divided into three major categories
with increasing complexity of reasoning
in program validation: sequential programming, multiprogramming,
and real-time programming.  By adhering
to a strict programming discipline and by using a suitable
high-level language molded after this discipline,
the complexity of reasoning about concurrency and execution
time constrain ts may be drastically reduced.
 This may be the only practical way to make real-time
systems analytically verifiable and ultimately
reliable.  A possible discipline is outlined and
expressed in terms of the language Modula.
.A
Wirth, N.
.K
multiprogramming, real-time programming, process synchronization,
processor sharing, program validation,
Modula
.I 2939
.T
Abstraction Mechanisms in CLU
.W
CLU is a new programming language designed to support
the use of abstractions in program construction.
 Work in programming methodology has led to the realization
that three kinds of abstractions-procedural,
control, and especially data abstractions-are useful
in the programming process.  Of these, only the
procedural abstraction is supported well by conventional
languages, through the procedure or subroutine.
 CLU provides, in addition to procedures, novel linguistic
mechanisms that support the use of data and
control abstractions.  This paper provides an in troduction
to the abstraction mechanisms in CLU.  By
means of programming examples, the utility of the three
kinds of abstractions in program construction
is illustrated, and it is shown how CLU programs may
be written to use and implement abstractions.  The
CLU library, which permits incremental program development
with complete type checking performed at compile
time, is also discussed.
.A
Liskov, B.
Snyder, A.
Atkinson, R.
Schaffert, C.
.K
programming languages, data types, data abstractions,
control abstractions, programming methodology,
separate compilation
.I 2940
.T
Abstraction and Verification in Alphard: Defining
and Specifying Iteration and Generators
.W
The Alphard "form" provides the programmer with
a great deal of control over the implementation
of abstract data types.  In this paper the abstraction techniques
are extended from simple data representation
and function definition to the iteration statement, the
most important poin t of interaction between data
and the control structure of the language itself.  A
means of specializing Alphard's loops to operate
on abstract entities without explicit dependence on the
representation of those entities is in troduced.
 Specification and verification techniques that allow
the properties of the generators for such iterations
to be expressed in the form of proof rules are developed.
 Results are obtained that for common special
cases of these loops are essentially identical to the
corresponding constructs in other languages.  A
means of showing that a generator will terminate is also provided.
.A
Shaw, M.
Wulf, W. A.
.K
abstraction and representation, abstract data types,
assertions, control specialization, correctness,
generators,invariants, iteration statements, modular
decomposition, program specifications, programming
languages, programming methodology, proofs of correctness, types, verification
.I 2941
.T
Early Experience with Mesa
.W
The experiences of Mesa's first users-primarily
its implementers-are discussed, and some implications
for Mesa and similar programming languages are suggested.
The specific topics addressed are: module structure
and its use in defining abstractions, data-structuring
facilities in Mesa, an equivalence algorithm for
types and type coercions, the benefits of the type system
and why it is breached occasionally, and the
difficulty of making the treatment of variant records safe.
.A
Geschke, C. M.
Morris, J. H. Jr.
Satterthwaite, E. H.
.K
programming languages, types, modules,
data structures, systems programming
.I 2942
.T
An Algol-Based Implementation of SNOBOL 4 Patterns
.A
Brownlee, J. N.
.K
patterns SNOBOL 4, pattern matching, string processing,
pattern implementation, algorithms in Pascal
.I 2943
.T
Lucid, a Nonprocedural Language with Iteration
.W
Lucid is a formal system in which programs
can be written and proofs of programs carried out.
 The proofs are particularly easy to follow and straightforward
to produce because the statements in
a Lucid program are simply axioms from which the proof
proceeds by (almost) conventional logical reasoning,
with the help of a few axioms and rules of inference
for the special Lucid functions.  As a programming
language, Lucid is unconventional because, among other
things, the order of statements is irrelevant
and assignment statements are equations.  Nevertheless,
Lucid programs need not look much different than
iterative programs in a conventional structured programming
language using assignment and conditional
statements and loops.
.A
Ashcrof, E. A.
Wadge, W. W.
.K
program proving, formal systems, semantics,
iteration, structured programming
.I 2944
.T
Shifting Garbage Collection Overhead to Compile Time
.W
This paper discusses techniques which enable automatic
storage reclamation overhead to be partially
shifted to compile time.  The paper assumes a transaction
oriented collection scheme, as proposed by
Deutsch and Bobrow, the necessary features of which are
summarized.  Implementing the described optimizations
requires global flow analysis to be performed on the
source program.  It is shown that at compile time
certain program actions that affect the reference counts
of cells can be deduced.  This information is
used to find actions that cancel when the code is executed
and those that can be grouped to achieve improved
efficiency.
.A
Barth, J. M.
.K
garbage collection, global flow analysis, list processing,
optimization, reference counts, storage
management
.I 2945
.T
Certification of Programs for Secure Information Flow
.W
This paper presents a certification mechanism
for verifying the secure flow of information
through a program.  Because it exploits the properties
of a lattice structure among security classes,
the procedure is sufficiently simple that it can easily
be included in the analysis phase of most existing
compilers.  Appropriate semantics are presented and
proved correct.  An important application is the
confinement problem: The mechanism can prove that a program
cannot cause supposedly nonconfidential results
to depend on confidential input data.
.A
Denning, D. E.
Denning, P. J.
.K
protection, security, information flow, program certification,
lattice, confinement, security classes
.I 2946
.T
An Alternative to Event Queues for Synchronization in Monitors
.W
In the monitor concept, as proposed by Brinch
Hansen and Hoare, event are used for synchronization.
  This paper describes another synchronizing primitive
which is nearly as expressive as the conditional
wait, but can be implemented more efficiently.  An implementation
of this primitive in terms of P and
V operations is given together with a correctness proof.
 Two examples are presented: the readers and
writers problem and the problem of information
streams sharing a finite buffer pool.
.A
Kessels, J. L. W.
.K
monitor, operating system, mutual exclusion, synchronization,
conditional critical region, structuring
concept
.I 2947
.T
SITAR: An Interactive Text Processing System for Small Computers
.W
SITAR, a low-cost in teractive text handling
and text analysis system for nontechnical users,
is in many ways comparable to in teractive bibliographical
search and retrieval systems, but has several
additional features. It is implemented on a PDP/11 time-sharing
computer invoked by a CRT with microprogrammed
editing functions.  It uses a simple command language designating
a function, a file, and a search template
consisting of the textual string desired and strings
delimiting the context in which the hit is to be
delivered.  Extensive experience with SITAR shows that
the combined powers of simple commands, string
orientation, circular file structure, a CRT with local
memory, and conversational computing produce a
system much more powerful than the sum of its parts.
.A
Schneider, B. R. Jr.
Watts, R. M.
.K
information retrieval, text editing, minicomputers,
CRTs,time sharing, bibliographic search and
retrieval, literary analysis, linguistic analysis, command languages
.I 2948
.T
A Terminal-Oriented Communication System
.W
This paper describes a system for full-duplex
communication between a time-shared computer
and its terminals.  The system consists of a communications
computer directly connected to the time-shared
system, a number of small remote computers to which
the terminals are attached, and connecting medium
speed telephone lines.  It can service a large number
of terminals of various types.  The overall system
design is presented along with the algorithms used to
solve three specific problems: local echoing, error
detection and correction on the telephone lines,
and multiplexing of character output.
.A
Heckel, P. G.
Lampson, B. W.
.K
terminal system, error correction, multiplexing,
local echoing, communication system, network
.I 2949
.T
A Correctness Proof of a Topology Information
Main tenance Protocol for a Distributed Computer
Network
.W
In order for the nodes of a distributed computer
network to communicate, each node must have
information about the network's topology.  Since nodes
and links sometimes crash, a scheme is needed
to update this information.  One of the major constrain ts
on such a topology information scheme is that
it may not involve a central controller.  The Topology
Information Protocol that was implemented on the
MERIT Computer Network is presented and explained; this
protocol is quite general and could be implemented
on any computer network.  It is based on Baran's "Hot
Potato Heuristic Routing Doctrine."  A correctness
proof of this Topology Information Protocol is also presented.
.A
Tajibnapis, W. D.
.K
distributed computer network, correctness proofs,
computer networks, distributed control, network
topology, routing problem in networks, distributed operating
system, store and forward packet switching,
store and forward message switching, traffic control
.I 2950
.T
A Unifying Approach to Scheduling
.W
This paper presents a scheme for classifying
scheduling algorithms based on an abstract model
of a scheduling system which formalizes the notion of
priority.  Various classes of scheduling algorithms
are defined and related to existing algorithms.  A
criterion for the implementation efficiency of an
algorithm is developed and results in the definition
of time-invariant algorithms, which include most
of the commonly implemented ones.  For time-invariant
algorithms, the dependence of processing rates
on priorities is derived.  The abstract model provides
a framework for implementing flexible schedulers
in real operating systems.  The policy-driven scheduler
of Bernstein and Sharp is discussed as an example
of such an implementation
.A
Ruschitzka, M.
Fabry, R. S.
.K
scheduling algorithms, scheduling models, priority,
operating systems,processor sharing, implementation
efficiency
.I 2951
.T
Dynamic Response Time Prediction for Computer Networks
.W
If the ultimate aim of a computing network
is resource sharing, then the human component as
well as the technical component of networking must
be fully investigated to achieve this goal.  This
research is a first step toward assisting the user in participating
in the vast store of resources available
on a network. Analytical, simulation, and statistical performance
evaluation tools are employed to investigate
the feasibility of a dynamic response time monitor
that is capable of providing comparative response
time information for users wishing to process various
computing applications at some network computing
node.  The research clearly reveals that sufficient
system data are currently obtainable, at least for
the five diverse ARPA network systems studied in detail,
to describe and predict the response time for
network time-sharing systems as it depends on some
measure of system activity or load level.
.A
Mamrak, S. A.
.K
response time monitor, computer networks, time-sharing
systems, comparative response time, ARPA
network, anlytic modeling, simulation, benchmark jobs, system measurement
.I 2952
.T
Functions Realizable with Word-Parallel Logical
and Two's-Complement Addition Instructions
.A
Warren, H. S. Jr.
.K
Boolean functions, two's-complement, sign propagation
.I 2953
.T
Notes on Recursion Elimination
.W
Various methods of recursion elimination are
applied to the schematic recursive procedure:
proc S(x); px then N(x); S(fx); S(gx); M(x) fi.  Procedures
with this general form arise in connection
with tree traversal and sorting algorithms.  Each method
of recursion removal involves the use of one
or more stacks, and the solutions are compared
on the basis of their running time.
.A
Bird, R. S.
.K
recursion elimination, optimization of programs,
stacks, trees, sorting algorithms, computational
induction
.I 2954
.T
A Bounded Storage Algorithm for Copying Cyclic Structures
.W
A new algorithm is presented which copies cyclic
list structures using bounded workspace and
linear time. Unlike a previous similar algorithm, this
one makes no assumptions about the storage allocation
system in use and uses only operations likely to be available
in a high-level language.  The distinctive
feature of this algorithm is a technique for traversing
the structure twice, using the same spanning
tree in each case, first from left to right and then from right to left.
.A
Robson J. M.
.K
copying, shared subtrees, cyclic structures
.I 2955
.T
Buddy Systems
.W
Two algorithms are presented for implementing
any of a class of buddy systems for dynamic storage
allocation.  Each buddy system corresponds to a set of
recurrence relations which relate the block sizes
provided to each other. Analyses of the in ternal fragmentation
of the binary buddy system, the Fibonacci
buddy system, and the weighted buddy system are given.
Comparative simulation results are also presented
for in ternal, external, and total fragmentation.
.A
Peterson, J. L.
Norman, T. A.
.K
dynamic storage allocation, buddy system, fragmentation,
Fibonacci buddy system, weighted buddy
system
.I 2956
.T
Some Ideas on Data Types in High-Level Languages
.W
A number of issues are explored concerning the
notion that a data type is a set of values together
with a set of primitive operations on those values.  Among
these are the need for a notation for iterating
over the elements of any finite set (instead of the
more narrow for i:= 1 to n notation), the use of
the domain of an array as a data type, the need for
a simple notation for allowing types of parameters
to be themselves parameters (but in a restrictive fashion),
and resulting problems with conversion of
values from one type to another.
.A
Gries, D.
Gehani, N.
.K
data types, generic procedures, programming languages
.I 2957
.T
Database Abstractions: Aggregation
.W
Aggregation is in troduced as an abstraction
which is important in conceptualizing the real
world.  Aggregation transforms a relationship between
objects into a higher-level object.  A new data
type, called aggregation, is developed which, under
certain criteria of "well-definedness," specifies
aggregation abstractions.  Relational databases defined
as collections of aggregates are structured as
a hierarchy on n-ary relations.  To main tain well-definedness,
update operations on such databases must
preserve two invariants.  Well-defined relations are
distinct from relations in third normal form.  It
is shown that these notions are complementary and both are
important in database design.  A top-down
methodology for database design is described which separates
decisions concerning aggregate structure
from decisions concerning key identification.  It is
suggested that aggregate types, and other types
which support real-world abstractions without in troducing
implementation detail, should be incorporated
into programming languages.
.A
Smith, J. M.
Smith, D. C. P.
.K
data abstraction, relational database, data type,
aggregation, database design, data structure,
knowledge representation, data definition language
.I 2958
.T
Abstract Data Types and the Development of Data Structures
.W
Abstract data types can play a significant role
in the development of software that is reliable,
efficient, and flexible.  This paper presents and discusses
the application of an algebraic technique
for the specification of abstract data types.  Among
the examples presented is a top-down development
of a symbol table for a block structured language; a discussion
of the proof of its correctness is given.
 The paper also contains a brief discussion of the problems
involved in constructing algebraic specifications
that are both consistent and complete.
.A
Guttag, J.
.K
abstract data type, correctness proof, data type,
data structure, specification, software specification
.I 2959
.T
The System for Business Automation (SBA): Programming Language
.W
The system for business automation (SBA) is a system
within which application experts-nonprogrammers-can
describe and execute their applications on a computer.
The user of SBA views his application as manipulation
of information in two-dimensional pictures of tables,
business forms, and reports on a display terminal.
 He can gradually automate this application by giving "examples"
to the system of how he manually manipulates
the information.  The Query-by-Example database language
is a subset of the SBA programming language.
.A
Zloof, M. M.
de Jong, S. P.
.K
programming language, graphics, user in terface,
data flow, forms flow, data abstraction, database,
query, data processing, business system specification, application programming
.I 2960
.T
Two Views of Data Abstraction
.A
Ledgard, H. F.
Taylor, R. W.
.I 2961
.T
Experimental Investigations of the Utility
of Detailed Flowcharts in Programming
.W
This paper describes previous research on
flowcharts and a series of controlled experiments
to test the utility of detailed flowcharts as an aid
to program composition, comprehension, debugging,
and modification.  No statistically significant difference
between flowchart and nonflowchart groups
has been shown, thereby calling into question the utility
of detailed flowcharting.  A program of further
research is suggested.
.A
Shneiderman, B.
Mayer, R.
McKay, D.
Heller, P.
.K
flowcharts, program composition, program comprehension,
debugging, modification, experimental testing,
human factors
.I 2962
.T
Production and Employment of Ph.D.'s in Computer Science-1976
.W
Statistics are presented on the production
and employment of Ph.D.'s in computer science for
the calendar year 1975-76.  Data include profiles of graduate
students and of faculty at 60 Ph.D.-producing
departments as well as a breakdown of degrees granted
by specialty areas.  Significant trends are noted
and comparisons with comparable data gathered
for the 1974-75 calendar year are made.
.A
Taulbee, O. E.
Conte, S. D.
.K
computer science, production of Ph.D.'s, employment, students
.I 2963
.T
A Fast Algorithm for Computing Longest Common Subsequences
.W
Previously published algorithms for finding
the longest common subsequence of two sequences
of length n have had a best-case running time of O(n^2).
 An algorithm for this problem is presented
which has a running time of O((r + n)log n), where r
is the total number of ordered pairs of positions
at which the two sequences match.  Thus in the worst
case the algorithm has a running time of O(n^2 log
n).  However, for those applications where most positions
of one sequence match relatively few positions
in the other sequence, a running time of O(n log n) can be expected.
.A
Hunt, J. W.
Szymanski, T. G.
.K
Longest common subsequence, efficient algorithms
.I 2964
.T
An Approach to Optimal Design of Storage Parameters in Databases
.A
Milman, Y.
.K
database organization, storage parameter
optimization, resident, overflow storage
.I 2965
.T
An Optimal Evaluation of Boolean Expressions in an Online Query System
.A
Hanani, M. Z.
.K
query, Boolean expression, information retrieval, file organization
.I 2966
.T
The Choice of Reference Poin ts in Best-Match File Searching
.W
Improvements to the exhaustive search method
of best-match file searching have previously been
achieved by doing a preprocessing step involving the
calculation of distances from a reference poin t.
  This paper discusses the proper choice of reference
poin ts and extends the previous algorithm to use
more than one reference poin t.  It is shown that reference
poin ts should be located outside of data clusters.
 The results of computer simulations are presented which
show that large improvements can be achieved
by the proper choice and location of multiple reference poin ts.
.A
Shapiro, M.
.K
matching, file searching, best match, nearest-neighbor classification
.I 2967
.T
A Comparison of Hardware and Software Associative
Memories in the Context of Computer Graphics
.W
The Associative Processing of Line Drawings (APLD)
System utilizes a hardware associative memory
and creates, modifies, deletes, stores, and retrieves
two-dimensional line drawings consisting of poin ts,
lines, rectangles, and triangles. The APLD functions
were duplicated on the TX-2 computer at M.I.T.'s
Lincoln Laboratory under the LEAP Language and Data
Structure,  A comparison of the hardware approach
with the software simulation illustrates the advantages
of the hardware associative memory in three areas:
(1) processing speed, (2) storage requirements, and (3)
flexibility.  The major problem areas of hardware
associative memory technology, namely input/output
and cost effectiveness, are also addressed.
.A
Stillman, N. J.
Berra, P. B.
.K
associative memory, associative processor, content-addressable
memory, graphics, information retrieval,
data structures, software evaluation, hardware evaluation,
parallel processing, database management
.I 2968
.T
A Comparison of Tree-Balancing Algorithms
.W
Several algorithms-height-balance (i.e. AVL
and extensions), weight-balance (i.e. BB and WB),
and total restructuring-for building balanced binary search
trees are compared.  The criteria for comparison
encompass theoretical aspects (e.g. path lengths) and implementation
independent and machine/algorithm-dependent
measures (e.g. run time).  A detailed analysis of code is
also presented at a level believed to be language-and
compiler-independent.  The quality of the resulting
trees and the overhead spent on building them are
analyzed, and some guidelines are given for an efficient
use of the methods.  If insertion and subsequent
queries are the only operations of in terest, then "pure"
AVL trees present the overall best qualities.
.A
Baer, J. L.
Schwab, B.
.K
binary search trees, AVL trees, weight-balanced trees,
path length, analysis of algorithms, information
storage and retrieval
.I 2969
.T
Optimal Program and Data Locations in Computer Networks
.W
An optimization procedure for the allocation
of program and data files in a computer network
is presented.  This algorithm takes into account the
dependencies between files and programs such as
occur in real heterogeneous computer networks.  Insights
into whether or not to convert programs from
one computer to another can also be gained from the
model.  A search procedure for the file location
problem is described, along with an example
and a possible application of the model.
.A
Morgan, H. L.
Levin, K. D.
.K
computer networks, databases, distributed
databases, optimal file location
.I 2970
.T
Achieving Specific Accuracy in Simulation Output Analysis
.W
This paper extends the use of the regenerative
property of queueing systems in the analysis
of simulation output.  In particular, it describes a
sequential estimation method which when used with
the regenerative property allows results to be obtained
with specified statistical accuracy.  This method
includes a test to check the normality assumption on
which the sequential procedure relies.  The paper
illustrates the method using the empty and idle state
as the regenerative state.  A second example then
describes how using the most frequently entered state
as the regenerative state reduces the chance of
making a costly error in a preliminary simulation run.
 The paper also described how a variance reduction
method due to Page [9] can be used to obtain a specified
accuracy with considerably fewer job completions
than are required when no variance reduction technique is applied.
.A
Fishman, G. S.
.K
confidence in terval, ratio estimator, regenerative
property, sequential estimator, simulation,
stopping rule, variance reduction
.I 2971
.T
SP/k: A System for Teaching Computer Programming
.W
SP/k is a compatible subset of the PL/I  language
that has been designed for teaching programming.
The features of the SP/k language were chosen to encourage
structured problem solving by computers, to
make the language easy to learn and use, to eliminate
confusing and redundant constructs, and to make
the language easy to compile.  The resulting language
is suitable for in troducing programming concepts
used in various applications, including business data
processing, scientific calculations and non-numeric
computation.  SP/k is actually a sequence of language
subsets called SP/1, SP/2,...SP/8.  Each subset
in troduces new programming language constructs while
retaining all the constructs of preceding subsets.
Each subset is precisely defined and can be learned
or implemented without the following subsets.
.A
Holt, R. C.
Wortman, D. B.
Barnard, D. T.
Cordy, J. R.
.K
programmer education, universities, community colleges,
high schools, PL/I, SP/k, minicomputers,
programming language design, teaching programming, in troductory computing
.I 2972
.T
Proof Techniques for Hierarchically Structured Programs
.W
A method for describing and structuring programs
that simplifies proofs of their correctness
is presented.  The method formally represents a program
in terms of levels of abstraction, each level
of which can be described by a self-contained nonprocedural
specification.  The proofs, like the programs,
are structured by levels.  Although only manual proofs
are described in the paper, the method is also
applicable to semi-automatic and automatic proofs.  Preliminary
results are encouraging, indicating that
the method can be applied to large programs, such as operating systems.
.A
Robinson, L.
Levitt, K. N.
.K
hierarchical structure, program verification, structured
programming, formal specification, abstraction,
and programming methodology
.I 2973
.T
Sorting on a Mesh-Connected Parallel Computer
.W
Two algorithms are presented for sorting n^2
elements on an n X n mesh-connected processor
array that require O(n) routing and comparison steps.
 The best previous algorithm takes time O(n log
n).  The algorithms of this paper are shown to be optimal
in time within small constant factors.  Extensions
to higher-dimensional arrays are also given.
.A
Thompson, C. D.
Kung, H. T.
.K
parallel computer, parallel sorting, parallel merge,
routing and comparison steps, perfect shuffle.
processor in terconnection pattern
.I 2974
.T
Comment on Weighted Increment Linear Search for Scatter Tables
.A
Bandyopadhyay, S. K.
.K
hash address, primary clustering, index,
sequence, complementary relation, search
.I 2975
.T
Remark on Uniform Insertion in Structured Data Structures
.A
Hollander, C.R.
.K
data structures, directed graphs, uniform insertion
.I 2976
.T
Approximating Block Accesses in Database Organizations
.A
Yao, S. B.
.K
database, inverted file organization, database performance
and measurement, information retrieval,
query answering
.I 2977
.T
The Stage Hypothesis and the S-Curve: Some Contradictory Evidence
.W
This paper presents the results of a study
testing the s-shaped budget curve of Nolan's stage
model of computer development in an organization.  Research
on the data processing budgets of California
counties fails to support the s-shaped curve or the use
of budgets as a basis for a stage model.  However,
the results do not invalidate the concept of a stage
model.  The analysis suggests an alternative model
of budget growth and a separation between models of budgeting
growth and growth stages in the development
of the computer resource.
.A
Lucac, H. C. Jr.
Sutton, J. A.
.K
budgets, stage theories, stage hypothesis
.I 2978
.T
Analysis of Design Alternatives for Virtual Memory Indexes
.W
A class of index structures for use in a virtual
memory environment is described.  Design alternatives
within this class of index structures are analyzed.  These
alternatives include a choice of search strategy,
whether or not pages in the index are structured, and
whether or not keys are compressed.  The average
cost of retrieving entries from these indexes is expressed
as a wieghted sum of the cost of a basic key
comparison and the cost of crossing a page boundary in
the index structure.  Formulas for the retrieval
costs for possible combinations of design alternatives
are given.  These are used in numerical case studies
which compare the retrieval costs of the alternatives.
 Qualitative comparisons of the main tenance costs
(insertion, deletion, reorganization) of the
design alternatives are also included.
.A
Maruyama, K.
Smith, S. E.
.K
index, index structure, pages, virtual memory,
files, retrieval, main tenance, search strategy,
key compression
.I 2979
.T
Studies in Machine Cognition Using The Game of Poker
.W
A progress report is presented of on-going
research efforts concerning human decision making
under uncertainly and risk and human problem solving
and learning processes on the one hand, and machine
learning, large scale programming systems, and novel
programming techniques on the other.  There has
also been in terest in how humans make deductive and inductive
inferences and form and optimize heuristic
rules, and how machines can reach similar results.
 Although the vehicle of these investigations has
been the game of poker, a conceptual framework has been
provided that should have a fairly wide range
of applicability.  The models of human judgment, choice,
and decision making are incorporated in a large
scale complex program.  They represent both descriptive
and normative theories of behavior. An in teractive
game environment has been recently established which,
besides its usefulness for experiments in game
playing, enables humans to construct machine strategies
"on-line" in a question answering, advice taking
mode.
.A
Findler, N. V.
.K
machine learning, game playing programs, decision
making under uncertain ty and risk, automatic
forming and optimizing of heuristic rules, automatic
inductive and deductive inference making, models
of game learning, poker, gambling and bluffing
.I 2980
.T
The Editing  of Picture Segmentations Using Local Analysis of Graphs
.W
A major problem in picture processing is the
elimination of the large number of spurious regions
that result from an initial segmentation by region growing
techniques.  Such regions have been eliminated
either on the basis of semantic information or on the
basis of size and contrast.  A scheme is presented
which performs eliminations on the basis of local properties
of the region adjacency graph.  The scheme
is based on definitions of graph properties which are
satisfied when a spurious region is present; then
editing is equivalent to fast graph operations.  A number of examples are shown.
.A
Tanimoto, S. L.
Pavlidis, T.
.K
picture processing, pattern recognition, segmentation, region editing
.I 2981
.T
Subgoal Induction
.W
A proof method, subgoal induction, is presented
as an alternative or supplement to the commonly
used inductive assertion method.  Its major virtue is that
it can often be used to prove a loop's correctness
directly from its input-output specification without the
use of an invariant.  The relation between subgoal
induction and other commonly used induction rules is explored
and, in particular, it is shown that subgoal
induction can be viewed as a specialized form of computation
induction.  A set of sufficient conditions
are presented which guarantee that an input-output specification
is strong enough for the induction steps
of a proof by subgoal induction to be valid.
.A
Morris, J. H. Jr.
Wegbreit, B.
.K
program verification, proving programs correct,
induction rule, computation induction, inductive
assertions, structural induction, proof rule,
recursive programs, iterative programs
.I 2982
.T
The Storage Requirement in Precedence Parsing
.A
Bertsch, E.
.K
precedence parsing, storage requirement, value table
.I 2983
.T
A Comparison of Next-fit, First-fit, and Best-fit
.A
Bays, C.
.K
memory allocation, first-fit, best-fit, next-fit
.I 2984
.T
Cost/Utilization: A Measure of System Performance
.W
A method is presented for evaluating computer
system performance in terms of a cost/utilization
factor and a measure of imbalance.  These coefficients
indicate the extent to which the total system
cost is effectively utilized.  The method includes a
technique for the visual representation of system
performance.
.A
Borovits, I.
Ein-Dor, P.
.K
computer system, performance evaluation, cost/utilization, system balance
.I 2985
.T
Effects of Chargeout on User/Manager Attitudes
.W
The relationship of in ternal pricing systems
for computer services (chargeout systems) and
user management attitudes about their computer-based
information systems is investigated. Evidence is
provided that the relationship conforms to a general
pattern that would be expected from the hypothesis
of the four stages of EDP growth [15].  The results also
indicate that the chargeout systems characteristic
of advanced EDP stage environments are associated with
relatively high levels of positive user attitudes
and marked increases in EDP training for users. Both factors
are important to the user/manager involvement
necessary for effective control of computer-based systems.
 Development and main tenance of computer-based
systems is asserted to be a category of organizational
change.  A "felt need" for the change on the part
of the user/manager is prerequisite to any change taking
place.  The research methods of behavioral science
are applied to investigate the user/manager
environment and the effects of chargeout.
.A
Nolan, R. L.
.K
computer management, computer budget,
chargeout, stage hypothesis, control
.I 2986
.T
Operations on Sparse Relations
.W
Various computations on relations, Boolean matrices,
or directed graphs, such as the computation
of precedence relations for a context-free grammar, can be
done by a practical algorithm that is asymptotically
faster than those in common use.  For example, how to compute
operator precedence or Wirth-Weber precedence
relations in O(n^2) steps is shown, as well as how to
compute linear precedence functions in O(n^2) steps
is shown, as well as how to compute linear precedence
functions in O(n) steps, where n is the size of
a grammer.  The heart of the algorithms is a general
theorem giving sufficient conditions under which
an expression whose operands are sparse relations and
whose operators are composition, transitive closure,
union, and inverse, can be computed efficiently.
.A
Hunt, H. B. III
Szymanski, T. G.
Ullman, J. D.
.K
computational complexity, sparse relation, Boolean
matrix, directed graph, Wirth-Weber precedence
relation, linear precedence function, SLR
grammar, T-canonical precedence relation
.I 2987
.T
Representation of Many-Sided Polygons
and Polygonal Lines for Rapid Processing
.W
A representation for polygons and polygonal
lines is described which allows sets of consecutive
sides to be collectively examined.  The set of sides are
arranged in a binary tree hierarchy by inclusion.
 A fast algorithm for testing the inclusion of a poin t
in a many-sided polygon is given.  The speed of
the algorithm is discussed for both ideal and practical
examples.  It is shown that the poin ts of intersection
of two polygonal lines can be located by what is essentially
a binary tree search.  The algorithm and
a practical example are discussed.  The representation
overcomes many of the disadvantages associated
with the various fixed-grid methods for representing curves and regions
.A
Burton W.
.K
boundary line representation, cartography, computer
graphics computer-searchable structures, contour
representation, geographic information processing, graphic
data retrieval, in tersection of curves, line-drawing
processing, poin ts in polygons, regional boundary
representation, spatial information
.I 2988
.T
Memory Management and Response Time
.W
This paper presents a computationally tractable
methodology for including accurately the effects
of finite memory size and workload memory requirements
in queueing network models of computer systems.
 Empirical analyses and analytic studies based on applying
this methodology to an actual multiaccess
in teractive system are reported.  Relations between workload
variables such as memory requirement distribution
and job swap time, and performance measures such as response
time and memory utilization are graphically
displayed. A multiphase, analytically soluble model is
proposed as being broadly applicable to the analysis
of in teractive computer systems which use nonpaged memories.
.A
Brown, R. M.
Browne, J. C.
Chandy, K. M.
.K
memory management, system performance, queueing
network models, in teractive computer systems
.I 2989
.T
Empirical Evaluation of Some Features
of Instruction Set Processor Architectures
.W
This paper presents methods for empirical evaluation
of features of Instruction Set Processors
(ISPs).  ISP features are evaluated in terms of the time
used or saved by having or not having the feature.
 The methods are based on analysis of traces of program
executions.  The concept of a register life is
in troduced, and used to answer questions like: How many
registers are used simultaneously? How many would
be sufficient all of the time? Most of the time? What
would the overhead be if the number of registers
were reduced? What are registers used for during their
lives? The paper also discusses the problem of
detecting desirable but non-existing instructions. Other
problems are briefly discussed.  Experimental
results are presented, obtained by analyzing 41
programs running on the DEC system 10 ISP.
.A
Lunde, A.
.K
computer architecture, program behavior, instruction
sets, op code utilization, register structures,
register utilization, simultaneous register
lives, instruction tracing, execution time
.I 2990
.T
Effective Information Retrieval Using Term Accuracy
.W
The performance of information retrieval systems
can be evaluated in a number of different
ways.  Much of the published evaluation work is based
on measuring the retrieval performance of an average
user query.  Unfortunately, formal proofs are difficult
to construct for the average case.  In the present
study, retrieval evaluation is based on optimizing the
performance of a specific user query.  The concept
of query term accuracy is in troduced as the probability
of occurrence of a query term in the documents
relevant to that query.  By relating term accuracy
to the frequency of occurrence of the term in the
documents of a collection it is possible to give formal
proofs of the effectiveness with respect to a
given user query of a number of automatic indexing systems
that have been used successfully in experimental
situations.  Among these are inverse document frequency
weighting, thesaurus construction, and phrase
generation.
.A
Yu, C. T.
Salton, G.
.K
information retrieval, automatic indexing, content
analysis, term accuracy, frequency weighting,
thesaurus and phrase transformations
.I 2991
.T
Improving the Access Time for Random Access Files
.W
Clustering in the key set is decreased by
smoothing the key-to-address transformation, and
by adding shadow buckets to an open chaining file.  The
keys are pre-hashed before the address division,
to remove the effect of sequential properties in the
key set.  Shadow buckets in the key search sequence
reduce the effect of nonuniformity in file loading,
and decrease the number of maximum probes needed
to locate a record.  The combined effects of these techniques
lead to improved file performance for secondary
storage devices, as shown by empirical studies.
.A
Clapson, P.
.K
hashing, hashing techniques, hashing methods, hash
coding, keys, key transformation, key-to-address
transformation, direct addressing, direct access, direct
access method, randomizing, random access, file
addressing, file organizations, file structures, scatter
storage, search method, collisions, synonyms,
clustering, information retrieval, open addressing, open
chaining, buckets, bucket size, shadow buckets,
combinatorics
.I 2992
.T
A Numbering System for Binary Trees
.A
Knott, G. D.
.K
binary trees, permutations, binary search trees, ranking function
.I 2993
.T
Occurrences of Cycling and Other Phenomena
Arising in a Class of Linear Programming Models
.W
An investigation into the average queue size
for a certain class of queues has resulted in
the formulation of linear programming problems which
are ill-conditioned in some cases.  In attempting
to solve these linear programming models, using IBM's
MPS package, instances of cycling were encountered.
 Small perturbations in the input data resulted in problems
which did not cycle.  This fact, plus several
other observed phenomena suggest that the primary reason
that cycling is not known to occur more frequently
is the round-off errors in the computations perturb
the problem sufficiently to prevent cycling (or at
least to prevent indefinite cycling).  In one case maximizing
and minimizing an objective function subject
to the same constrain t set was attempted, but MPS solved
only one of these while giving an indication
of infeasibility for the other.
.A
Kotiah, T. C. T.
Steinberg, D. I.
.K
linear programming, cycling, queueing models
.I 2994
.T
A Linear Algorithm for Incremental Digital Display of Circular Arcs
.W
Circular arcs can be drawn on an incremental
display device such as a cathode ray tube, digital
plotter, or matrix prin ter using only sign testing and
elementary addition and subtraction.  This paper
describes methodology for producing dot or
step patterns closet to the true circle.
.A
Bresenham, J.
.K
graphics, circle drawing, step generation, dot
generation, incremental digital plotting, raster
display, integer arithmetic, circle algorithm
.I 2995
.T
Decomposability, Instabilities, and Saturation
in Multiprogramming Systems (Corrigendum)
.A
Courtois, P. J.
.I 2996
.T
Transient-Free Working-Set Statistics
.W
Transient-free average working set size and transient-free
missing-page rate for a finite sample
of a reference string are defined.  Use of these statistics
is appropriate if the contents of the working
set at the start of the recorded string are unknown.
 If a certain stationarity condition holds, these
statistics provide unbiased estimates of expected working-set
sizes, missing-page probabilities, and
in terreference distance probabilities.  Two other pairs
of estimators are shown to be biased.  Expressions
for the transient-free statistics are obtained in terms
of in terval statistics. Several methods of computation
are discussed, the usefulness of each depending on length
of the sample, number of distinct references,
and the amount of main storage available to the computer
performing the calculations.  In particular,
methods are described for handling long strings
containing many distinct page names.
.A
Easton, M. C.
Bennett, B. T.
.K
working set, estimation program behavior
.I 2997
.T
Convex Hulls of Finite Sets of Poin ts in Two and Three Dimensions
.W
The convex hulls of sets of n poin ts in two
and three dimensions can be determined with O(n
log n) operations.  The presented algorithms use the "divide
and conquer" technique and recursively apply
a merge procedure for two nonin tersecting convex hulls.
 Since any convex hull algorithm requires at
least O(n log n) operations, the time complexity of the
proposed algorithms is optimal within a multiplicative
constant.
.A
Preparata, F. P.
Hong, S. J.
.K
computational complexity, convex hull, optimal algorithms,
planar set of poin ts, spatial set of
poin ts
.I 2998
.T
An Empirical Study of List Structure in Lisp
.W
Static measurements of the list structure of
five large Lisp programs are reported and analyzed
in this paper.  These measurements reveal substantial
regularity, or predictability, among poin ters to
atoms and especially among poin ters to lists.  Pointers
to atoms are found to obey, roughly, Zipf's law,
which governs word frequencies in natural languages; poin ters
to lists usually poin t to a location physically
nearby in memory.  The use of such regularities in the
space-efficient representation of list structure
is discussed.  Linearization of lists, whereby successive
cdrs (or cars) are placed in consecutive memory
locations whenever possible, greatly strengthens the
observed regularity of list structure.  It is shown
that under some reasonable assumptions, the entropy or
information content of a car-cdr pair in the programs
measured is about 10 to 15 bits before linearization,
and about 7 to 12 bits after.
.A
Clark, D. W.
Green, C. C.
.K
list structure measurement, Lisp, list structure
regularity, poin ter compression, Zipf's law, list
linearization, poin ter entropy
.I 2999
.T
An Approach to Multidimensional Data Array Processing by Computer
.W
Some recent work on the development of general-purpose
computer-based statistical and data
processing capabilities for handling multidimensional
arrays of data is presented. Attention is first
given to some of the general problems of multidimensional
table and array processing.  This is followed
by a summary of some recent developments in array processing
capabilities at the World Bank, in particular,
the system identified as WRAPS(World Bank
Retrieval and Array Processing System).
.A
Muller, M. E.
.K
array processing, table processing, statistical
analysis, data retrieval, data processing, syntax
for data structures, computing techniques, time series, cross tabulation
.I 3000
.T
Segment Sizes and Lifetimes in Algol 60 Programs
.W
The characteristics of the virtual memory requirements
of a sample of Algol 60 programs have
been measured.  Distributions are presented for thesizes
of memory requests and for their holding times
(lifetimes).  The results are presented in terms of Johnston's
contour model and a simple abstract machine.
 They provide new empirical evidence of certain aspects
of the construction and behavior of real programs,
and some of their implications for the design of virtual
memory systems are presented and discussed.
.A
Batson, A. P.
Brundage, R. E.
.K
virtual memory, program behavior, segmentation,
storage allocation, Algol 60, contour model
.I 3001
.T
Detection of Combined Occurrences
.W
In this paper it is supposed that the variables
X1,...,Xn each have finite range with the variable
Xi taking on Pi possible values and that the values of the
variables are changing with time.  It is supposed
further that it is desired to detect occurrences in which
some subset of the variables achieve particular
values.  Finally, it is supposed that the problem involves
the detection of a large number of combined
occurrences for a large number of changes of values of
variables.  Two efficient solutions for this problem
are described.  Both methods have the unusual property
of being faster for systems where the sum P1 + ...
+ Pn is larger. The first solution is error-free
and suitable for most cases.  The second solution
is slightly more elegant and allows negation as well
as conjunction, but is subject to the possibility
of errors.  An error analysis is given for the second
method and an empirical study is reported.
.A
Zobrist, A. L.
Carlson, F. R. Jr.
.K
coding, hash coding, retrieval, secondary keys, pattern
recognition, artificial in telligence, demons,
n-tuples, sorting, chess
.I 3002
.T
A Record and File Partitioning Model
.W
One of the main objectives in the design of
a file system is the reduction of storage and data
transfer costs.  This paper presents a model in which
several  requests access the file system, and each
request requires information from one or more variable
length data-items.  The probabilities of access
and the distribution of each data-item's length are assumed
to be known, and to be mutually independent.
The file system uses one or more storage devices, and
each record may be partitioned into subrecords
that are stored on different devices.  One of the subrecords
is designated as the primary record; when
a request for a record is made, the primary record is
first accessed, and other subrecords are accessed
only if the pertinent information is not stored in the
primary record.  The model that is presented in
this paper, both as a nonlinear programming model and
a mixed integer programming model, is a very general
one; several types of file systems may be derived from
it by an appropriate selection of its parameters.
 This model has already been used in the optimization of
library routines' storage at a large scale operating
system.
.A
Babad, J. M.
.K
file system, file design, file partitioning, record partitioning
.I 3003
.T
A Survey of the Literature in Computer
Science Education Since Curriculum '68
.W
A bibliography of approximately two hundred
references in computer science education appearing
in the literature since the publication of "Curriculum
'68" is presented.  The bibliography itself is
preceded by brief descriptive materials organizing the
references into the categories of survey reports,
activities of professional organizations, philosophy
of programs, description of  programs, description
of courses and other materials.
.A
Austing, R. H.
Barnes, B. H.
.K
education, computer science, curricula
.I 3004
.T
Structured Programming in Cobol: An Approach for Application Programmers
.W
Techniques for designing and writing Cobol programs
are presented.  Previous work in structured
programming is drawn upon and adapted.  The presentation
is informal: the terminology is nonmathematical
as far as possible, no theorems are proved, and examples
are used frequently.  Top-down program design
is implemented through the use of structured flowcharts,
disciplined specifications, and step by step
verification.  A well-formed Cobol program is defined.
 The proper use of the GO TO and other Cobol coding
practices are discussed.
.A
Van Gelder, A.
.K
structured programming, top-down, well-formed program,
GO TO statement, repeat statement, flowchart,
application programming, Cobol, software reliability, program verification
.I 3005
.T
Implications of Structured Programming for Machine Architecture
.W
Based on an empirical study of more than 10,000
lines of program text written in a GOTO-less
language, a machine architecture specifically designed for
structured programs is proposed.  Since assignment,
CALL, RETURN, and IF statements together account for
93 percent of all executable statements, special
care is given to ensure that these statements can be implemented
efficiently.  A highly compact instruction
encoding scheme is presented, which can reduce program
size by a factor of 3.  Unlike a Huffman code,
which utilizes variable length fields, this method uses
only fixed length (1-byte) op code and address
fields.  The most frequent instructions consist of a
single 1-byte field.  As a consequence, instruction
decoding time is minimized, and the machine is
efficient with respect to both space and time.
.A
Tanenbaum, A.S.
.K
machine architecture, computer architecture, computer
organization, instruction set design, program
characteristics
.I 3006
.T
Anomalies with Variable Partition Paging Algorithms
.W
Five types of anomalous behavior which may
occur in paged virtual memory operating systems
a redefined.  One type of anomaly, for example, concerns
the fact that, with certain reference strings
and paging algorithms, an increase in mean memory allocation
may result in an increase in fault rate.
 Two paging algorithms, are examined in terms of their
anomaly potential, and reference string examples
of various anomalies are presented.  Two paging algorithm
properties, the inclusion property and the
generalized inclusion property, are discussed and the
anomaly implications of these properties presented.
.A
Franklin, M.A.
Graham, G.S.
Gupta, R.K.
.K
anomaly, memory management, program behavior, stack
algorithms, virtual memory, working set, page
fault frequency, paging algorithms
.I 3007
.T
Complexity of Computations (Corrigendum)
.A
Rabin, M.O.
.I 3008
.T
Preserving Average Proximity in Arrays
.W
Programmers and data structure designers are often
forced to choose between alternative structures.
 In storing these structures, preserving logical adjacencies
or "proximity" is usually an important consideration.
 The combinatorial problem of storing arrays as various
kinds of list structures is examined.  Embeddings
of graphs are used to model the loss of proximity involved
in such storage schemes, and an elementary
proof that arrays cannot be stored as linear lists with
bounded loss of proximity is presented.  Average
loss of proximity is then considered, and it is shown
that arrays cannot be stored as linear lists with
only bounded loss of average proximity, but can be so
stored in binary trees.  The former result implies,
for instance, that row major order is an asymptotically
optimal storage strategy for arrays.
.A
DeMillo, R.A.
Eisenstat, S.C.
Lipton, R.J.
.K
arrays, graph embedding, linear lists,
proximity, average proximity, trees
.I 3009
.T
Insertions and Deletions In One-Sided Height-Balanced Trees
.W
Recently Hirschberg has established that insertions
into one-sided height-balanced trees can
be done in 0(log^2N) steps.  It is proved here that deletions
can also be performed in 0(log^2N) steps,
which answers the open problem posed by Hirschberg.
.A
Kosaraju, S.R.
.K
AVL trees, balanced trees, binary search, dynamic balancing
.I 3010
.T
Value Orientation of Computer Science Students
.W
Technological and nontechnological value orientations
are investigated with special attention
to the complexity of value structures.  Computer science
students, who are closely associated with technology,
contrast with social science students, who are often
technologically aloof.  This is confirmed by the
value ratings of 313 students at the University of Minnesota
in 1972.  Computer science majors were found
to have a more complex value structure than social science majors.
.A
Anderson, R.E.
.K
values, attitudes, students, public, social effects
.I 3011
.T
Management Utilization of Computers in American Local Governments
.W
Traditional concepts of management information
systems (MIS) bear little relation to the information
systems currently in use by top management in most US local
governments.  What exists is management-oriented
computing, involving the use of relatively unsophisticated
applications.  Despite the unsophisticated
nature of these systems, management use of computing is
surprisingly common, but also varied in its extent
among local governments.  Management computing is most
prevalent in those governments with professional
management practices where top management is supportive
of computing and tends to control computing decisions
and where department users have less control over design
and implementation activities.  Finally, management
computing clearly has impacts for top managers, mostly
involving improvements in decision information.
.A
Dutton, W.H.
Kraemer, K.L.
.K
computer utilization, management information system,
American local government, city government
computers, county government computers, computer impacts, management computing
.I 3012
.T
The Use of an Interactive Information Storage
and Retrieval System in Medical Research
.W
This paper presents the results of a study
of the use of an interactive computerized storage
and retrieval system.  A monitor built into the computer
system provided usage data for the study.  Additional
data on user reactions were gathe red from a questionnaire.
 The results show the important role played
by frequently chosen laboratory reference leaders in influencing
the use of this system.  The implications
of the study for the design of similar systems are discussed.
.A
Lucas, H.C.Jr.
.K
implementation, system use, information storage and retrieval system
.I 3013
.T
Some New Methods of Detecting Step Edges in Digital Pictures
.W
This note describes two operators that respond
to step edges, but not to ramps.  The first
is similar to the digital Laplacian, but uses the max, rather
than the sum, of the x and y second differences.
 The second uses the difference between the mean and
median gray levels in a neighborhood.  The outputs
obtained from these operators applied to a set of test
pictures are compared with each other and with
the standard digital Laplacian and gradient.  A third
operator, which uses the distance between the center
and centroid of a neighborhood as an edge value, is also
briefly considered; it turns out to be equivalent
to one of the standard digital approximations to the gradient.
.A
Schachter, B.J.
Rosenfeld, A.
.K
image processing, pattern recognition, edge detection
.I 3014
.T
Is "Sometime" Sometimes Better than "Always"? (Intermittent
Assertions in Proving Program Correctness)
.W
This paper explores a technique for proving the
correctness and termination of programs simultaneously.
 This approach, the intermittent-assertion method, involves
documenting the program with assertions that
must be true at some time when control passes through
the corresponding point, but that need not be true
every time.  The method, introduced by Burstall, promises
to provide a valuable complement to the more
conventional methods.  The intermittent-assertion method
is presented with a number of examples of correctness
and termination proofs.  Some of these proofs are markedly
simpler than their conventional counterparts.
 On the other hand, it is shown that a proof of correctness
or termination by any of the conventional
techniques can be rephrased directly as a proof using
intermittent assertions.  Finally, it is shown
how the intermittent-assertion method can be applied
to prove the validity of program transformations
and the correctness of continuously operating programs.
.A
Manna, Z.
Waldinger, R.
.K
intermittent assertions, correctness of programs,
termination of programs, program verification,
program transformation, continuously operating programs.
.I 3015
.T
Relaxation Methods for Image Reconstruction
.W
The problem of recovering an image (a function
of two variables) from experimentally available
integrals of its grayness over thin strips is of great
importance in a large number of scientific areas.
 An important version of the problem in medicine is
that of obtaining the exact density distribution
within the human body from X-ray projections.One approach
that has been taken to solve this problem
consists of translating the available information into
a system of linear inequalities.  The size and
the sparsity of the resulting system (typically, 25,000
inequalities with fewer than 1 percent of the
coefficients nonzero) makes methods using successive
relaxations computationally attractive, as compared
to other ways of solving systems of inequalities.
In this paper, it is shown that, for a consistent
system of linear inequalities, any sequence of relaxarion parameters
lying strictly between 0 and 2 generates
a sequence of vectors which converges to a solution.
 Under the same assumptions, for a system of linear
equations, the relaxation method converges to the minimum
norm solution.  Previously proposed techniques
are shown to be special cases of our procedure with
different choices of relaxation parameters.  The
practical consequences for image reconstruction of the
choice of the relaxation parameters are discussed.
.A
Herman, G.T.
Lent, A.
Lutz, P.H.
.K
biomedical image processing, image reconstruction,
X-ray tomography, mathematical programming,
linear inequalities, relaxation techniques
.I 3016
.T
A Comparison of Numerical Techniques in Markov Modeling
.W
This paper presents several numerical methods which
may be used to obtain the stationary probability
vectors of Markovian models.  An example of a nearly
decomposable system is considered, and the results
obtained by the different methods examined.  A post
mortem reveals why standard techniques often fail
to yield the correct results.  Finally, a means of estimating
the error inherent in the decomposition
of certain models is presented.
.A
Stewart, W.J.
.K
Markov models, numerical techniques, simultaneous
iteration, near-decomposability
.I 3017
.T
B-trees Re-examined
.W
The B-tree and its variants have, with increasing
frequency, been proposed as a basic storage
structure for multiuser database applications.  Here,
three potential problems which must be dealt with
in such a structure that do not arise in more traditional
static directory structures are indicated.
 One problem is a possible performance penalty.
.A
Held, G.
Stonebraker, M.
.K
B-tree, directory, static directory, dynamic
directory, index sequential access method
.I 3018
.T
Covering Edges by Cliques with Regard to
Keyword Conflicts and Intersection Graphs
.W
Kellerman has presented a method for determining
keyword conflicts and described a heuristic
algorithm which solves a certain combinatorial optimization
problem in connection with this method.
This optimization problem is here shown to be equivalent
to the problem of covering the edges of a graph
by complete subgraphs with the objective of minimizing
the number of complete subgraphs.  A relationship
between this edge-clique-cover problem and the graph coloring
problem is established which allows algorithms
for either one of these problems to be constructed
from algorithm for the other.  As consequences of
this relationship, the keyword conflict problem and the
edge-clique-cover problem are shown to be NP-complete,
and if P=/NP then they do not admit polynomial-time approximation
algorithms which always produce solutions
within a factor less than 2 from the optimum.
.A
Kou, L.T.
Stockmeyer, L.J.
Wong, C.K.
Watson, T.J.
.K
keyword conflicts, intersection graphs, node clique
cover, edge clique cover, computational complexity,
NP-complete problems, polynomial-time heuristics
.I 3019
.T
The GRE Advanced Test in Computer Science
.A
Austing, R.H.
.I 3020
.T
Systematic Recursion Removal
.W
The recursion removal algorithm presented
by Strong and Walker is amplified and applied to
a relatively complex PL/I program.  The aim is to demonstrate
systematic recursion-removal techniques
on something more complex than Knuth's "sturdy toddler"
and to obtain measurements of the cost of procedure
linkage in PL/I and the savings achievable via procedure
integration in the presence of recursion.  First,
the paper describes the recursion-removal process and the
example on which it will be illustrated.  Recursion
removal is then applied to the two major parts of this
example and the final result of the process is
displayed.  Our performance comparison results are presented
and our conclusions are briefly discussed.
.A
Auslander, M.A.
Strong, H.R.
.K
recursion removal, recursion elimination, optimization,
procedure linkage, procedure integration
.I 3021
.T
A Method for Obtaining Digital Signatures and Public-Key Cryptosystems
.W
An encryption method is presented with the novel
property that publicly revealing an encryption
key does not thereby reveal the corresponding decryption
key.  This has two important consequences: (1)
Couriers or other secure means are not needed to transmit
keys, since a message can be enciphered using
an encryption key publicly revealed by the intended recipient.
 Only he can decipher the message, since
only he knows the corresponding decryption key.  (2)
A message can be "signed" using a privately held
decryption key.  Anyone can verify this signature using
the corresponding publicly revealed encryption
key.  Signatures cannot be forged, and a signer cannot
later deny the validity of his signature.  This
has obvious applications in "electronic mail" and "electronic
funds transfer" systems.  A message is
encrypted by representing it as a number M, raising
M to a publicly specified power e, and then taking
the remainder when the result is divided by the publicly
specified product, n, of two large secret prime
numbers p and q.  Decryption is similar;only a different,
secret, power d is used, where e * d = 1 (mod(p-1)
* (q-1)).  the security of the system rests in part on
the difficulty of factoring the published divisor,
n.
.A
Rivest, R.L.
Shamir, A.
Adleman, L.
.K
digital signatures, public-key cryptosystems,
privacy, authentication, security, factorization,
prime number, electronic mail, message-passing,
electronic funds transfer, cryptography.
.I 3022
.T
Computer Science Faculties: The Current Status of Minorities and Women
.W
The results of a survey conducted in the fall
of 1975 to determine the status of women and
minority faculty members in academic computer science
are presented.  Faculty members were compared with
respect to professional background, salaries, teaching
load, publication records, and research grants.
 Analysis of the data indicated that the over-all verdict
is one of general equality among women, minorities,
and men.
.A
Mamrak, S.A.
Montanelli, R.G.Jr.
.K
discrimination against women, discrimination against
minorities, faculty, computer science degree
programs, affirmative action, teaching loads, salaries, publications
.I 3023
.T
Architecture of the IBM System/370
.W
This paper discusses the design considerations
for the architectural extensions that distinguish
System/370 from System/360.  It comments on some experiences
with the original objectives for System/360
and on the efforts to achieve them, and it describes the
reasons and objectives for extending the architecture.
It covers virtual storage, program control, data-manipulation
instructions, timing facilities, multiprocessing,
debugging and monitoring, error handling, and input/output
operations.  A final section tabulates some
of the important parameters of the various IBM
machines which implement the architecture.
.A
Case, R.P.
Padges, A.
.K
computer systems, architecture, instruction
sets, virtual storage, error handling
.I 3024
.T
The CRAY-1 Computer System
.W
This paper describes the CRAY-1, discusses
the evolution of its architecture, and gives an
account of some of the problems that were overcome during
its manufacture.  The CRAY-1 is the only computer
to have been built to date that satisfies ERDA's Class
VI requirement (a computer capable of processing
from 20 to 60 million floating point operations per
second) [1].  The CRAY-1's Fortran compiler (CFT)
is designed to give the scientific user immediate access
to the benefits of the CRAY-1's vector processing
architecture.  An optimizing compiler, CFT, "vectorizes"
innermost DO loops.  Compatible with the ANSI
1966 Fortran Standard and with many commonly supported
Fortran extensions, CFT does not require any source
program modifications or the use of additional nonstandard
Fortran statements to achieve vectorization.
 Thus the user's investment of hundreds of man months
of effort to develop Fortran programs for other
contemporary computers is protected.
.A
Russell, R.M.
.K
architecture, computer systems
.I 3025
.T
The Evolution of the DEC system 10
.W
The DEC system 10, also known as the PDP-10, evolved
from the PDP-6 (circa 1963) over five generations
of implementations to presently include systems covering
a price range of five to one.  The origin and
evolution of the hardware, operating system, and languages
are described in terms of technological change,
user requirements, and user developments. The PDP-10's
contributions to computing technology include:
accelerating the transition from batch oriented to time
sharing computing systems; transferring hardware
technology within DEC (and elsewhere) to minicomputer
design and manufacturing; supporting minicomputer
hardware and software development; and serving as a
model for single user and timeshared interactive
minicomputer/microcomputer systems.
.A
Bell, C.G.
Kotok, A.
Hastings, T.N.
Hill, R.
.K
computer structures, architecture, operating system, timesharing
.I 3026
.T
The Evolution of the Sperry Univac 1100
Series: A His tory, Analysis, and Projection
.W
The 1100 series systems are Sperry Univac's
large-scale main frame computer systems.  Beginning
with the 1107 in 1962, the 1100 series has progressed
through a succession of eight compatible computer
models to the latest system, the 1100/80, introduced
in 1977.  The 1100 series hardware architecture
is based on a 36-bit word, ones complement structure
which obtains one operand from storage and one from
a high-speed register, or two operands from high-speed
registers.  The 1100 Operating System is designed
to support a symmetrical multiprocessor configuration
simultaneously providing multiprogrammed batch,
timesharing, and transaction environments.
.A
Borgherson, B.R.
Hanson, M.L.
Hartley, P.A.
.K
1100 computer series, computer architecture, multiprocessing
languages, data management systems,
end user facilities, executive control software
.I 3027
.T
The Development of the MU5 Computer System
.W
Following a brief outline of the background
of the MU5 project, the aims and ideas for MU5
are discussed.  A description is then given of the instruction
set, which includes a number of features
conducive to the production of efficient compiled code
from high-level language source programs.  The
design of the processor is then traced from the initial
ideas for an associatively addressed "name store"
to the final multistage pipeline structure involving
a prediction mechanism for instruction prefetching
and a function queue for array element accessing.  An
overall view of the complete MU5 complex is presented
together with a brief indication of its performance.
.A
Ibbett, R.N.
Capon, P.C.
.K
architecture, naming, virtual storage, instruction
set, descriptor, pipeline, instruction buffering,
associative storage, function queue, computer complex
.I 3028
.T
The Manchester Mark I and Atlas: A His torical Perspective
.W
In 30 years of computer design at Manchester University
two systems stand out: the Mark I (developed
over the period 1946-49) and the Atlas (1955-62).
This paper places each computer in its his torical
context and then describes the architecture and system
software in present-day terminology.  Several
design concepts such as address-generation and store
management have evolved in the progression from
Mark I to Atlas.  The wider impact of Manchester innovations
in these and other areas is discussed, and
the contemporary performance of the Mark I and Atlas is evaluated.
.A
Lavington, S.H.
.K
architecture, index registers, paging, virtual
storage, extra codes, compilers, operating systems,
Ferranti, Manchester Mark I, Atlas, ICL
.I 3029
.T
Foreword to the Special Issue on Computer Architecture
.A
Fuller,S.H.
.I 3030
.T
An Example of Hierarchical Design and Proof
.W
Hierarchical programming is being increasingly
recognized as helpful in the construction of
large programs.  Users of hierarchical techniques claim
or predict substantial increases in productivity
and in the reliability of the programs produced.  In this
paper we describe a formal method for hierarchical
program specification, implementation, and proof.  We
apply this method to a significant list processing
problem and also discuss a number of extensions to current
programming languages that ease hierarchical
program design and proof.
.A
Spitzen, J.M.
Levitt, K.N.
Robinson, L.
.K
Program verification, specification, data abstraction,
software modules, hierarchical structures
.I 3031
.T
Abstract Data Types and Software Validation
.W
A data abstraction can be naturally specified
using algebraic axioms.  The virtue of these
axioms is that they permit a representation-independent
formal specification of a data type.  An example
is given which shows how to employ algebraic axioms at
successive levels of implementation.  The  major
thrust of the paper is twofold.  First, it is shown how
the use of algebraic axiomatizations can simplify
the process of proving the correctness of an implementation
of an abstract data type.  Second, semi-automatic
tools are described which can be used both to automate
such proofs of correctness and to derive an immediate
implementation from the axioms.  This implementation
allows for limited testing of programs at design
time, before a conventional implementation is accomplished.
.A
Guttag, J.V.
Horowitz, E.
Musser, D.R.
.K
Abstract data type, correctness proof,
data type, data structure, specification
.I 3032
.T
Reverse Path Forwarding of Broadcast Packets
.W
A broadcast packet is for delivery to all
nodes of a network.  Algorithms for accomplishing
this delivery through a store-and-forward packet switching
 computer network include (1) transmission
of separately addressed packets. (2) multidestination
addressing, (3) hot potato forwarding,(4) spanning
tree forwarding, and (5) source based forwarding.  To
this list of algorithms we add (6) reverse path
forwarding, a broadcast routing method which exploits
routing procedures and data structures already
available for packet switching.  Reverse path forwarding
is a practical algorithm for broadcast routing
 in store-and-forward packet switching computer networks.
 The algorithm is described as being practical
 because it is not optimal according to metrics developed
for its analysis in this paper, and also because
it can be implemented in existing networks with less complexity
than that required for the known alternatives.
.A
Dalal, Y.K.
Metcalfe, R.M.
.K
Reverse path forwarding, broadcast packets, routing,
computer networks, store-and-forward packet
switching, broadcast protocols
.I 3033
.T
Optimizing Decision Trees Through Heuristically Guided Search
.W
Optimal decision table conversion has been
tackled in the literature using two approaches,
dynamic programming and branch-and-bound.  The former
technique is quite effective, but its time and
space requirements are independent of how "easy" the
given table is.  Furthermore, it cannot be used
to produce good, quasi optimal solutions.  The branch-and-bound
technique uses a good heuristic to direct
the search, but is cluttered up by an enormous search
space, since the number of solutions increases
with the number of test variables according to a double
exponential.  In this paper we suggest a heuristically
guided top-down search algorithm which, like dynamic
programming, recognizes identical subproblems but
which can be used to find both optimal and quasi optimal
solutions.  The heuristic search method introduced
in this paper combines the positive aspects of the above
two techniques.  Compressed tables with a large
number of variables can be handled without deriving expanded tables first.
.A
Martelli, A.
Montanari, U.
.K
Decision table, optimal decision table conversion,
decision tree, heuristic search, AND/OR graphs,
dynamic programming, branch-and-bound
.I 3034
.T
Detection of Logical Errors in Decision Table Programs
.W
In this paper an algorithm to detect logical
errors in a limited-entry decision table and in
loop-free programs with embedded decision tables is developed.
 All the conditions in the decision tables
are assumed to be inequalities or equalities relating
linear expressions.  It is also assumed that actions
in a decision table are linear in variables which occur
in the condition stub of the decision table (or
tables) to which control is transferred from the table.
 The algorithm is based on determining whether
a set of linear inequalities has or does not have a
solution.  The algorithm described in the paper is
implemented in Fortran IV.
.A
Ibramsha, M.
Rajaraman, V.
.K
Error diagnostics, decision tables
.I 3035
.T
A Strategic Planning Methodology for the Computing
Effort in Higher Education: An Empirical Evaluation
.W
The findings of a study designed to address
the pressing problems associated with the strategic
planning of the computing effort in higher education
are presented here.  A planning methodology was
developed and tested through implementation at a university.
 Two years after the methodology was implemented,
the effectiveness of the planning methodology was assessed
in terms of the improvement of the delivery
of computing services to the major institutional roles
of instruction, research, and administration.
 Two control institutions were employed to contrast the
improvements at the test institution.  The results
of the research indicate the planning methodology significantly
enhanced the delivery of computing services.
.A
Wetherbe, J.C.
Dock, V.T.
.K
Computer management, computer budget,
university computing, computer planning
.I 3036
.T
The Selection of Optimal Tab Settings
.W
A new generation of computer terminals allows
tab settings to be selected and set by the computer.
 This feature can be used to reduce the number of characters
that are needed to represent a document
for transmission and printing.  In this note, an algorithm
is given for selecting the optimal set of
tab stops for minimizing the number of characters transmitted.
 An implementation of the algorithm has
reduced the number of characters transmitted by from
7 to 30 percent, but requires a prepass through
the document to compute a matrix used in determining
the optimal set tab stops.  The use of fixed tab
stops, as a heuristic alternative, can achieve
about 80 percent of optimal with no prepass.
.A
Peterson, J.L.
Bitner, J.R.
Howard, J.H.
.K
Tabs, word processing, dynamic programming
.I 3037
.T
A Linear Sieve Algorithm for Finding Prime Numbers
.W
A new algorithm is presented for finding all
primes between 2 and n.  The algorithm executes
in time proportional to n (assuming that multiplication
of integers not larger than n can be performed
in unit time).  The method has the same arithmetic complexity
as the algorithm presented by Mairson [6];
however, our version is perhaps simpler and more elegant.
 It is also easily extended to find the prime
factorization of all integers between 2 and n in time proportional to n.
.A
Gries, D.
Misra, J.
.K
Primes, algorithms, data structures
.I 3038
.T
Using Encryption for Authentication in Large Networks of Computers
.W
Use of encryption to achieve authenticated
communication in computer networks is discussed.
 Example protocols are presented for the establishment
of authenticated connections, for the management
of authenticated mail, and for signature verification
and document integrity guarantee.  Both conventional
and public-key encryption algorithms are considered as the basis for protocols.
.A
Needham, R.M.
Schroeder, M.D.
.K
Encryption, security, authentication, networks, protocols,
public-key cryptosystems, data encryption
standard
.I 3039
.T
On-the-Fly Garbage Collection: An Exercise in Cooperation
.W
As an example of cooperation between sequential
processes with very little mutual interference
despite frequent manipulations of a large shared data
space,  a technique is developed which allows nearly
all of the activity needed for garbage detection and collection
to be performed by an additional processor
operating con-currently with the processor devoted to the
computation proper.  Exclusion and synchronization
constraints have been kept as weak as could be achieved;
the severe complexities engendered by doing
so are illustrated.
.A
Dijkstra, E.W.
Lamport, L.
Martin, A.J.
Scholten, C.S.
Steffens, E.F.M.
.K
Multiprocessing, fine-grained interleaving, cooperation
between sequential processes with minimized
mutual exclusion, program correctness for multiprogramming
tasks, garbage collection
.I 3040
.T
Synthesizing Constraint Expressions
.W
A constraint network representation is presented
for a combinatorial search problem: finding
values for a set of variables subject to a set of constraints.
 A theory of consistency levels in such
networks is formulated, which is related to problems
of backtrack tree search efficiency.  An algorithm
is developed that can achieve any level of consistency
desired, in order to preprocess the problem for
subsequent backtrack search, or to function as an alternative
to backtrack search by explicitly determining
all solutions.
.A
Freuder, E.C.
.K
Backtrack, combinatorial algorithms, constraint
networks, constraint satisfaction, graph coloring,
network consistency, relaxation, scene labeling, search
.I 3041
.T
Median Split Trees: A Fast Lookup Technique for Frequently Occuring Keys
.W
Split trees are a new technique for searching sets
of keys with highly skewed frequency distributions.
 A split tree is a binary search tree each node of which
contains two key values-a node value which is
a maximally frequent key in that subtree, and a split
value which partitions the remaining keys (with
respect to their lexical ordering) between the left and
right subtrees.  A median split tree (MST) uses
the lexical median of a node's descendents as its split
value to force the search tree to be perfectly
balanced, achieving both a space efficient representation
of the tree and high search speed.  Unlike
frequency ordered binary search trees, the cost of a
successful search of an MST is log n bounded and
very stable around minimal values.  Further, an MST
can be built for a given key ordering and set of
frequencies in time n log n, as opposed to n2 for an
optimum binary search tree.  A discussion of the
application of MST's to dictionary lookup for English is
presented, and the performance obtained is contrasted
with that of other techniques.
.A
Sheil, B.A.
.K
Tree search, dictionary lookup, binary search, heaps,
balanced trees, Zipf's Law, information retrieval
.I 3042
.T
Power Trees
.W
The new class of Pk trees is presented, where
height balance is maintained for the nodes Iying
on particular paths.  The number of nodes of a Pk tree
asymptotically grows as a power of the height,
in the worst case.  A procedure for node insertion is given,
and the class of trees  considered is restricted
to IPk trees, which are buildable by such a procedure.
 The average behavior of such trees, studied by
an extensive set of simulation runs, is close to that
of AVL trees.  In particular, the family of IPO
trees whose main advantage is the reduced number of
restructurings required after node insertion, is
analyzed.
.A
Luccio, F.
Pagli, L.
.K
Binary search trees, Pk trees, IPk trees, search
length, node insertion, subtree rotation
.I 3043
.T
Distributed Processes: A Concurrent Programming Concept
.W
A language concept for concurrent processes
without common variables is introduced.  These
processes communicate and synchronize by means of procedure
calls and guarded regions.  This concept
is proposed for real-time applications controlled by
microcomputer networks with distributed storage.
 The paper gives several examples of distributed processes
and shows that they include procedures, coroutines,
classes, monitors, processes, semaphores, buffers, path
expressions, and input/output as special cases.
.A
Hansen, P.
.K
Concurrent programming, distributed processes,
microprocessor networks, nondeterminism, guarded
regions, programming languages, process communication
and scheduling, sorting arrays, coroutines, classes,
monitors, processes, semaphores, buffers, path expressions, input/output
.I 3044
.T
A Note on Conditional Expressions
.W
Evaluation of a conditional expression may succeed
even when the "deciding predicate" diverges
and the alternatives are records (or nodes) whose fields have different content.
.A
Friedman, D.P.
Wise, D.S.
.K
Parallel evaluation, suspending cons, Lisp, conditional
forms, if-then-else, ambiguous function,
infinite structures
.I 3045
.T
A Simple Recovery-Only Procedure For SImple Precedence Parsers
.W
A simple method is described enabling simple
precedence parsers to recover from syntax errors.
 No attempt to repair errors is made, yet parsing and
most semantic processing can continue.  The result
is a good "first approximation" to syntax error handling
with negligible increase in parsing time, space,
and complexity of both the parser and its table generator.
.A
Ripley, D.G.
.K
Syntax errors, error recovery, parsing,
simple precedence, compilers, debugging
.I 3046
.T
Computer Generation of Gamma Random Variables - II
.W
A rejection method is proposed for generating
gamma variates with nonintegral shape parameter
a, a > 1. This method is similar to other methods given
by Fishman, Wallace, and Tadikamalla and is faster
than these methods for a> 2.  The core storage requirements
and the programming effort for the proposed
method are similar to those of Wallace's or Tadikamalla's
methods.  The computational times for the proposed
method remain fairly constant for medium and large
values of a and are superior to times obtained by
Ahrens and Dieter's method for all values of a.  The
proposed method is simpler than Ahrens and Dieter's
method.
.A
Tadikamalla, P.R.
.K
Gamma variables, rejection method, computer methods
.I 3047
.T
Using Synthetic Images to Register Real Images with Surface Models
.W
A number of image analysis tasks can benefit
from registration of the image with a model of
the surface being imaged.  Automatic navigation using visible
light or radar images requires exact alignment
of such images with digital terrain models.  In addition,
automatic classification of terrain, using
satellite imagery, requires such alignment to deal correctly
with the effects of varying sun angle and
surface slope.  Even inspection techniques for certain
industrial parts may be improved by this means.
We achieve the required alignment by matching the real
image with a synthetic image obtained from a surface
model and known positions of the light sources.  The
synthetic image intensity is calculated using the
reflectance map, a convenient way of describing surface reflection
as a function of surface gradient.
 We illustrate the technique using LANDSAT images and digital terrain models.
.A
Horn, B.K.P.
Bachman, B.L.
.K
Image registration, synthetic images, surface models,
automatic hill shading, digital terrain models,
image transformation, image matching, shaded images
.I 3048
.T
Performance Evaluation of Highly Concurrent
Computers by Deterministic Simulation
.W
Simulation is presented as a practical technique
for performance evaluation of alternative
configurations of highly concurrent computers.  A technique
is described for constructing a detailed
deterministic simulation model of a system.  In the model
a control stream replaces the instruction and
data streams of the real system.  Simulation of the
system model yields the timing and resource usage
statistics needed for performance evaluation, without
the necessity of emulating the system.  As a case
study, the implementation of a simulator of a model
of the CPU-memory subsystem of the IBM 360/91 is
described.  The results of evaluating some alternative
system designs are discussed.  The experiments
reveal that, for the case study, the major bottlenecks
in the system are the memory unit and the fixed
point unit.  Further, it appears that many of the sophisticated
pipelining and buffering technique simplemented
in the architecture of the IBM 360/91 are of little
value when high-speed (cache) memory is used, as
in the IBM 360/195.
.A
Kumar, B.
Davidson, E.S.
.K
Performance evaluation, deterministic simulation,
control stream, concurrent computers
.I 3049
.T
A Simply Extended and Modified Batch
Environment Graphical System (SEMBEGS)
.W
SEMBEGS is a complete batch environment graphical
system containing components for handling
graphical data files, for displaying the contents of
these files on a variety of graphical hardware,
and for performing graphical batch input operations.
 SEMBEGS is easy to extend and modify to meet the
growing needs of a large batch environment, and is even
extendable to a fully interactive system.  The
paper presents the conceptual view of graphics leading
to the design of SEMBEGS and outlines the major
components of the system.  The design of SEMBEGS is founded
upon the basic assumption that the true aim
of computer graphics is to describe graphical entities,
rather than, as commonly held, to provide graphical
input and output functional capabilities.  SEMBEGS
is built around a Basic Graphical Data Management
System (BAGDAMS) which provides a common means of communicating
the descriptions of graphical entities
 between the various components of SEMBEGS.  BAGDAMS
provides facilities for storing, retrieving, and
manipulating the descriptions of graphical entities
provided by, and received by application programs,
graphics packages, and graphical devices.
.A
Wendorf, J.W.
.K
Computer graphics, data structures, graphic display,
graphic input, graphical database, device
independent graphics
.I 3050
.T
Systems Design Education: A Gaming Approach
.W
One of the problems facing managers of computer
installations is the problem of configuring
the computer system to meet the demands made by the
mix of jobs that the computer center must service.
 This paper presents a management game that allows
the player to configure a computer system to meet
a hypothetical job mix is under the control of a game administrator
and can be varied to simulate a variety
of real-world situations (I/O bound jobs, compute bound
jobs, etc.).  The player of the game receives
a set of detailed reports on the cost of his choices
and a simulated run of the center operating under
his choices.
.A
Lyons, N.R.
.K
System design, configuration, management game
.I 3051
.T
A Comparison of Heaps and the TL Structure for the SImulation Event Set
.W
None
.A
Franta, W.R.
Maly, K.
.K
Simulation,event set, heaps, TL structure
.I 3052
.T
Cold-Start vs. Warm-Start Miss Ratios
.W
In a two-level computer storage hierarchy, miss
ratio measurements are often made from a "cold
start," that is made with the first-level  store initially
empty.  For large capacities the effect on
the measured miss ratio of the misses incurred while
filling the first-level store can be significant,
even for long reference strings.  Use of "warm-start"
rather than "cold-start" miss ratios cast doubt
on the widespread belief that the observed "S-shape" of
lifetime (reciprocal of miss ratio) versus capacity
curve indicates a property of behavior of programs that
maintain a constant number of pages in main storage.
 On the other hand, if cold-start miss ratios are measured
as a function of capacity and measurement
length, then they are useful in studying systems in which
operation of a program is periodically interrupted
by task switches.  It is shown how to obtain, under simple
assumptions, the cache miss ratio for multiprogramming
from cold-start miss ratio values and how to obtain
approximate cold-start miss ratios from warm-start
miss ratios.
.A
Easton, M.C.
Fagin, R.
.K
Miss ratio, cold start, warm start, storage hierarchy,
lifetime function, multiprogramming, S-shape
.I 3053
.T
Packed Scatter Tables
.W
Scatter tables for open addressing benefit
from recursive entry displacements, cutoffs for
unsuccessful searches, and auxiliary cost functions.  Compared
with conventional methods, the new techniques
provide substantially improved tables that resemble exact-solution
optimal packings.  The displacements
are depth-limited approximations to an enumerative
(exhaustive) optimization, although packing costs
remain linear-O(n)-with table size n.  The techniques are
primarily suited for important fixed (but possibly
quite large) tables for which reference frequencies may
be known: op-code tables,spelling dictionaries,
access arrays.  Introduction of frequency weights further
improves retrievals, but the enhancement may
degrade cutoffs.
.A
Lyon, G.
.K
Assignment problem, backtrack programming, hashing, open
addressing, recursion, scatter table rearrangements
.I 3054
.T
Implementing Quicksort Programs
.W
This paper is a practical study of how to
implement the Quicksort sorting algorithm and its
best variants on real computers, including how to apply
various code optimization techniques.  A detailed
implementation combining the most effective improvements
to Quicksort is given, along with a discussion
of how to implement it in assembly language.  Analytic
results describing the performance of the programs
are summarized.  A variety of special situations are considered
from a practical standpoint to illustrate
Quicksort's wide applicability as an internal sorting
method which requires negligible extra storage.
.A
Sedgewick, R.
.K
Quicksort, analysis of algorithms, code optimization, sorting
.I 3055
.T
An Analysis of Algorithms for the Dutch National Flag Problem
.W
Solutions to the Dutch National Flag Problem
have been given by Dijkstra [1] and Meyer [3].
 Dijkstra starts with a simple program and arrives at
an improved program by refinement.  Both of the
algorithms given by Dijkstra are shown to have an expected number
of swaps which is 2/3N + 0(1) and that
these values differ at most by 1/3 of a swap and asymptotically
by 1/4 of a swap.  The algorithm of Meyer
is shown to have expected swap complexity 5/9N.
.A
McMaster, C.L.
.K
Algorithmic analysis, Dutch National Flag
Problem, refinement, structured programming
.I 3056
.T
Counting Large Numbers of Events in Small Registers
.W
It is possible to use a small counter to keep
approximate counts of large numbers.  The resulting
expected error can be rather precisely controlled.  An
example is given in which 8-bit counters (bytes)
are used to keep track of as many as 130,000 events with
a relative error which is substantially independent
of the number n of events.  This relative error can
be expected to be 24 percent or less 95 percent of
the time (i.e.o = n/8).  The techniques could be used
to advantage in multichannel counting hardware
or software used for the monitoring of experiments or processes.
.A
Morris, R.
.K
Counting
.I 3057
.T
Optimal His togram Matching by Monotone Gray Level Transformation
.W
This paper investigates the problem of optimal
his togram matching using monotone gray level
transformation, which always assigns all picture points
of a given gray level i to another gray level
T(i) such that if i > j, then T(i) > T(j).  The objective
is to find a transformed digital picture of
a given picture such that the sum of absolute errors
between the gray level his togram of the transformed
picture and that of a reference picture is minimized.
 This is equivalent to placing k1 linearly ordered
objects of different sized one by one into k2 linearly ordered
boxes of assorted sizes, such that the
accumulated error of space under packed or overpacked
in the boxes is minimized; the placement function
is monotonic, which ensures a polynomial time solution
to this problem.  A tree search algorithm for
optimal his togram matching is presented which has time
complexity O(k1 x k2).  If the monotone property
is dropped, then the problem becomes NP-complete,
even if it is restricted to k2 = 2.
.A
Chang, S.K.
Wong, Y.W.
.K
Optimal his togram matching, gray level transformation,
packing problem, tree searching algorithm,
picture processing
.I 3058
.T
Jump Searching: A Fast Sequential Search Technique
.W
When sequential file structures must be used
and binary searching is not feasible, jump searching
becomes an appealing alternative.  This paper explores
variants of the classic jump searching scheme
where the optimum jump size is the square root of the
number of records.  Multiple level and variable
size jump strategies are explored, appropriate applications
are discussed and performance is evaluated.
.A
Shneiderman, B.
.K
Jump searching, sequential files, file management,
search strategies, database structures, index
searching
.I 3059
.T
Models for Parallel Processing WIthin Programs:
Application to CPU:I/O and I/O:I/O Overlap
.W
Approximate queueing models for internal parallel
processing by individual programs in a multiprogrammed
system are developed in this paper.  The solution technique
is developed by network decomposition.  The
models are formulated in terms of CPU:I/O and I/O:I/O overlap
and applied to the analysis of these problems.
 The percentage performance improvement from CPU:I/O
overlap is found to be greatest for systems which
are in approximate CPU:I/O utilization balance and for
low degrees of multiprogramming.  The percentage
improvement from I/O:I/O overlap is found to be greatest
for systemtems in which the I/O system is more
utilized than the CPU.
.A
Towsley, D.
Chandy, K.M.
Browne, J.C.
.K
Multiprogramming, parallel processing, queueing
network models, multiprocessing of computation
and I/O
.I 3060
.T
Fortran 77
.W
There is a new standard Fortran.  The official
title is "American National Standard Programming
Language Fortran, X3.9-1978," but it is more commonly
referred to as "Fortran 77," since its development
was completed in 1977.  It replaces the Fortran standard
designated X3.9-1966.  This paper describes
many of the features of Fortran 77 and also provides
some information about how and why the standard
was developed.
.A
Brainerd, W.
.K
None
.I 3061
.T
Simulations of Dynamic Sequential Search Algorithms
.W
None
.A
Tenenbaum, A.
.K
Searching, list processing, sequential
searching, dynamic reordering, simulation
.I 3062
.T
Real Time Plotting of Approximate Contour Maps
.W
None
.A
Ward, S.A.
.K
Contour map, digital plotting, graphical characters
.I 3063
.T
A Note on Virtual Memory Indexes
.W
None
.A
Maly, K.
.K
Index, B-tree, pages, file organization,
linked representation, maintenance costs
.I 3064
.T
Event Manipulation for Discrete Simulations
Requiring Large Numbers of Events
.W
The event-manipulation system presented here consists of
two major parts.  The first part addresses
the familiar problem of event scheduling efficiency
when the number of scheduled events grows large.
 The second part deals with the less apparent problem
of providing efficiency and flexibility as scheduled
events are accessed to be executed.  Additional features
and problems dealt with include the proper handling
of simultaneous events; that certain events must be created,
scheduled, and executed at the same points
in simulated time; that infinite loops caused by the concatenation
of such "zero-time" events are possible
and must be diagnosed; that maintaining various event
counts is practical and economical; and that a
capability for handling  "time-displaceable" events is desirable and possible.
.A
Ulrich, E.G.
.K
Simulation, discrete systems simulation, discrete
event simulation, time-flow mechanisms
.I 3065
.T
Right Brother Trees
.W
Insertion and deletion are provided for the
class of right (or one-sided) brother trees which
have O (log n) performance.  The importance of these
results stems from the close relationship of right
brother trees which have an insertion algorithm operating
in O (log2 n).  Further, although both insertion
and deletion can be  carried out in O (log n) time for
right brother trees, it appears that the insertion
algorithm is inherently much more difficult than the
deletion algorithm-the reverse of what one usually
obtains.
.A
Ottmann, T.T.
Six, H.W.
Wood, D.
.K
Dictionary problem, search trees, AVL trees, brother
trees, right-balanced trees,one-sided height-balanced
trees, insertion and deletion algorithms
.I 3066
.T
A Controlled Experiment in Program Testing
and Code Walkthroughs/Inspections
.W
This paper describes an experiment in program
testing, employing 59 highly experienced data
processing professionals using seven methods to test
a small PL/I program.  The results show that the
popular code walk through/inspection method was as effective
as other computer-based methods in finding
errors and that the most effective methods (in terms of
errors found and cost) employed pairs of subjects
who tested the program independently and then pooled
their findings.  The study also shows that there
is a tremendous amount of variability among subjects
and that the ability to detect certain types of
errors varies from method to method.
.A
Myers, G.J.
.K
Software reliability, program verification, debugging,
testing, code walkthroughs, code inspections,
personnel selection
.I 3067
.T
Generalized Working Sets for Segment Reference Strings
.W
The working-set concept is extended for programs
that reference segments of different sizes.
 The generalized working-set policy (GWS) keeps as its
resident set those segments whose retention costs
do not exceed their retrieval costs.  The GWS is a model
for the entire class of demand-fetching memory
policies that satisfy a resident-set inclusion property.
 A generalized optimal policy (GOPT) is also
defined; at its operating points it minimizes aggregated
retention and swapping costs.  Special cases
of the cost structure allow GWS and GOPT to simulate
any known stack algorithm, the working set, and
VMIN.  Efficient procedures for computing demand curves
showing swapping load as a function of memory
usage are developed for GWS and GOPT policies.  Empirical
data from an actual system are included.
.A
Denning, P.J.
Slutz, D.R.
.K
Database referencing, memory management, optimal
memory policies, paging, program behavior, program
measurement, segmentation, working sets
.I 3068
.T
A Model for Verification of Data Security in Operating Systems
.W
Program verification applied to kernel architectures
forms a promising method for providing
uncircumventably secure, shared computer systems.  A
precise definition of data security is developed
here in terms of a general model for operating systems.
 This model is suitable as a basis for verifying
many of those properties of an operating system which
are necessary to assure reliable enforcement of
security.  The application of this approach to the
UCLA secure operating system is also discussed.
.A
Popek, G.J..
Farber, D.A.
.K
Operating systems, security, protection, program verification
.I 3069
.T
A Practical Interprocedural Data Flow Analysis Algorithm
.W
A new interprocedural  data flow analysis algorithm
is presented and analyzed.  The algorithm
associates with each procedure in a program information
about which variables may be modified, which
may be used, and which are possibly preserved by a call
on the procedure, and all of its subcalls.  The
algorithm is sufficiently powerful to be used on recursive
programs and to deal with the sharing of variables
which arises through reference parameters.  The algorithm
is unique in that it can compute all of this
information in a single pass, not requiring a prepass to
compute calling relationships or sharing patterns.
 The algorithm is asymptotically optimal in time complexity.
 It has been implemented and is practical
even on programs which are quite large.
.A
Barth, J.M.
.K
Data flow analysis, global flow analysis, optimization,
side effects, relations, reference parameters,
incarnations
.I 3070
.T
Hybrid Simulation Models of Computer Systems
.W
This paper describes the structure and operation
of a hybrid simulation model in which both
discrete-event simulation and analytic techniques are
combined to produce efficient yet accurate system
models.  In an example based on a simple hypothetical
computer system, discrete-event simulation is used
to model the arrival and activation of jobs, and a
central-server queueing network models the use of
system processors.  The accuracy and efficiency of the
hybrid technique are demonstrated by comparing
the result and computational costs of the hybrid model of
the example with those of an equivalent simulation-only
model.
.A
Schwetman, H.D.
.K
Performance evaluation, simulation, queueing
network models, central server model
.I 3071
.T
An Algorithm Using Symbolic Techniques for the
Bel-Petrov Classification of Gravitational Fields
.W
In this note, an algorithm is presented for the
symbolic calculation of certain algebraic invariants
of the Weyl tensor which permits the determination
of the Bel-Petrov types of a gravitational field.
 This algorithm, although more specialized than that
of D'Inverno and Russell-Clark, requires neither
the use of a special coordinate system nor the spin coefficient
formalism.  The algorithm has been implemented
in FORMAC and is designed to complete the classification
scheme proposed by Petrov in his book.  An appendix
contains examples illustrating the use of the algorithm.
.A
Harris, R.A.
Zund, J.D.
.K
General relativity, Bel-Petrov types,
FORMAC, symbolic manipulation, tensors
.I 3072
.T
Feedback Coupled Resource Allocation Policies
in the Multiprogramming- Multiprocessor Computer
System
.W
Model studies of some integrated, feedback-driven
scheduling systems for multiprogrammed- multiprocessor
computer systems are presented.  The basic control variables
used are the data-flow rates for the processes
executing on the CPU.  The model systems feature simulated
continuous-flow and preempt-resume scheduling
of input-output activity.  Attention is given to the
amount of memory resource required for effective
processing of the I/O activity (buffer space assignment).
 The model studies used both distribution-driven
and trace-driven techniques.  Even relatively simple dynamic
schedulers are shown to improve system performance
(as measured by user CPU time) over that given by optimal
or near-optimal static schedulers imbeded
in identical system structures and workload environments.
 The improvement is greatest under a heavy
I/O demand workload.
.A
Brice, R.S.
Browne, J.C.
.K
Integrated schedulers, feedback scheduling,
multiprogramming systems, I/O system scheduling
.I 3073
.T
Communicating Sequential Processes
.W
This paper suggests that input and output are
basic primitives of programming and that parallel
composition of communicating sequential processes is
a fundamental program structuring method.  When
combined with a development of Dijkstra's guarded command,
these concepts are surprisingly versatile.
 Their use is illustrated by sample solutions of
a variety of familiar programming exercises.
.A
Hoare, C.A.R.
.K
Programming, programming languages, programming primitives,
program structures, parallel programming,
concurrency, input, output, guarded commands, nondeterminacy,
coroutines, procedures, multiple entries,
multiple exits, classes, data representations, recursion,
conditional critical regions, monitors, iterative
arrays
.I 3074
.T
A Time- and Space- Efficient Garbage Compaction Algorithm
.W
Given an area of storage containing scattered,
marked nodes of differing sizes, one may wish
to rearrange them into a compact mass at one end of the
area while revising all pointers to marked nodes
to show their new locations.  An algorithm is described
here which accomplishes this task in linear time
relative to the size of the storage area, and in a space
of the order of one bit for each pointer.  The
algorithm operates by reversibly encoding the situation
(that a collection of locations point to a single
location) by a linear list, emanating from the pointed-to
location, passing through the pointing locations,
and terminating with the pointed-to location's transplanted contents.
.A
Morris, F.L.
.K
Garbage collection, compaction, compact ification,
storage reclamation, storage allocation, record
structures, relocation, list processing, free storage, pointers, data structures
.I 3075
.T
Fast Parallel Sorting Algorithms
.W
A parallel bucket-sort algorithm is presented
that requires time O(log n) and the use of n
processors.  The algorithm makes use of a technique that
requires more space than the product of processors
and time.  A realistic model is used model is used in which
no memory contention is permitted.  A procedure
is also presented to sort n numbers in time O(k log
n) using n 1 + 1/k processors, for k an arbitrary
integer.  The model of computation for this procedure
permits simultaneous fetches from the same memory
location.
.A
Hirschberg, D.S.
.K
Parallel processing, sorting, algorithms, bucket sort
.I 3076
.T
Value Conflicts and Social Choice in Electronic
Funds Transfer System Developments
.W
During the last few years, computer-based
systems which automate the transfer and recording
of debits and credits have begun to be implemented on
a large scale.  These systems promise both financial
benefits for the institutions that use them and potential
conveniences to their customers.  However,
they also raise significant social, legal, and technical
questions that must be resolved if full scale
systems for Electronic Funds Transfer (EFT) are not
to cause more problems for the larger public than
they solve.  This paper examines the incentives for EFT
developments and the social problems they raise
in the context of conflicts between five different value
positions that are often implicit in analyses
of proposed EFT arrangements.  These conflicts reflect
the relative importance of certain problems for
specific groups.  The value positions implicit in EFT proposals
help to organize analyses of market arrangements,
system reliability, and privacy of transactions.  These
topics are analyzed in this article and related
to the value positions held by concerned parties.  Last,
the ways in which the public can learn about
the social qualities of different EFT arrangements and
the pace of EFT developments are both discussed
in the context of social choice.
.A
Kling, R.
.K
Electronic funds transfer systems, social impacts
of computing, privacy, social choice, computer
networks, network reliability, security, social values
.I 3077
.T
Can Programming Be Liberated from the von Neumann
Style?  A Functional Style and Its Algebra
of Programs
.W
Conventional programming languages are growing
ever more enormous, but not stronger.  Inherent
defects at the most basic level cause them to be both
fat and weak: their primitive word-at-a-time style
of programming inherited from their common ancestor-the
von Neumann computer, their close coupling off
semantics to state transitions, their division of programming
into a world of expressions and a world
of statements, their inability to effectively use powerful
combining forms for building new programs
from existing ones, and their lack of useful mathematical
properties for reasoning about programs. An
alternative functional style of programming is founded
on the use of combining forms for creating programs.
 Functional programs deal with structured data, are often
nonrepetitive and nonrecursive, are hierarchically
constructed, do not name their arguments, and do not require
the complex machinery of procedure declarations
to become generally applicable.  Combining forms can
use high level programs to build still higher level
ones in a style not possible in conventional languages.
 Associated with the functional style of programming
is an algebra of programs whose variables range over
programs and whose operations are combining forms.
 This algebra can be used to transform programs and
to solve equations whose "unknowns" are programs
in much the same way one transforms equations in high
school algebra.  These transformations are given
by algebraic laws and are carried out in the same language
in which programs are written.  Combining
forms are chosen not only for their programming power
but also for the power of their associated algebraic
laws.  General theorems of of the algebra give the detailed
behavior and termination conditions for large
classes of programs.  A new class of computing systems
uses the functional programming style both in
its programming language and in its state transition
rules.  Unlike von Neumann languages, these systems
have semantics loosely coupled to states-only one
state transition occurs per major computation.
.A
Backus, J.
.K
Functional programming, algebra of programs, combining
forms, functional forms, programming languages,
von Neumann computers, von Neumann languages, models of
computing systems, applicative computing systems,
applicative state transition systems, program transformation,
program correctness, program termination,
metacomposition
.I 3078
.T
Analysis of the Availability of Computer
Systems Using Computer- Aided Algebra
.W
Analytical results, related to the availability
of a computer system constructed of unreliable
processors, are presented in this paper.  These results
are obtained by using various computer-aided
algebraic manipulation techniques.  A major purpose of
this paper is to demonstrate that the difficulties
of obtaining analytical solutions to Markov processes
can be considerably reduced by the application
of symbol manipulation programs.  Since many physical
systems can be modeled by Markov and semi-Markov
processes, the potential range of application of these techniques
is much wider than the problem of availability
analyzed here.
.A
Chattergy, R.
Pooch, U.W.
.K
Computer-aided algebra, symbol manipulation, Markov
process, reliability, redundant structures,
on-line computer system.
.I 3079
.T
An Algorithm for Reasoning About Equality
.W
A simple technique for reasoning about equalities
that is fast and complete for ground formulas
with function symbols and equality is presented.
 A proof of correctness is given as well.
.A
Shostak, R.E.
.K
Theorem proving, deduction, program verification, equality
.I 3080
.T
Proving the Correctness of Heuristically Optimized Code
.W
A system for proving that programs written
in a high level language are correctly translated
to a low level language is described.  A primary use of
the system is as a post optimization step in code
generation.  The low level language programs need not
be generated by a compiler and in fact could be
hand coded.  Examples of the usefulness of such a system
are given.  Some interesting results are the
ability to handle programs that implement recursion by
bypassing the start of the program, and the detection
and pinpointing of a wide class of errors in the low
level language programs.  The examples demonstrate
that optimization of the genre of this paper can result
in substantially faster operation and the saving
of memory in terms of program and stack sizes.
.A
Samet, H.
.K
Compilers, correctness, code optimization,
debugging, program verification, Lisp
.I 3081
.T
Shallow Binding in Lisp 1.5
.W
Shallow binding is a scheme which allows the
value of a variable to be accessed in a bounded
amount of computation.  An elegant model for shallow binding
in  Lisp 1.5 is presented in which context-switching
is an environment tree transformation called rerooting.
 Rerooting is completely general and reversible,
and is optional in the sense that a Lisp 1.5 interpreter
will operate correctly whether or not rerooting
is invoked one very context change.   Since rerooting
leaves assoc [v, a] invariant, for all variables
v and all environments a, the programmer can have access
to a rerooting primitive, shallow[], which gives
him dynamic control over whether accesses are shallow or
deep, and which affects only the speed of execution
of a program, not its semantics.  In addition, multiple
processes can be active in the same environment
structure, so long as rerooting is an indivisible operation.
 Finally, the concept of rerooting is shown
to combine the concept of shallow binding in Lisp with
Dijkstra's display for Algol and hence is a general
model for shallow binding.
.A
Baker, H.G. Jr.
.K
Lisp 1.5, environment trees, FUNARG'S, shallow binding,
deep binding, multiprogramming, Algol display
.I 3082
.T
Time, Clocks, and the Ordering of Events in a Distributed System
.W
The concept of one event happening before
another in a distributed system is examined, and
is shown to define a partial ordering of the events.
 A distributed algorithm is given for synchronizing
a system of logical clocks which can be used to totally
order the events.  The use of the total ordering
is illustrated with a method for solving synchronization
problems.  The algorithm is then specialized
for synchronizing physical clocks, and a bound is derived
on how far out of synchrony the clocks can
become.
.A
Lamport, L.
.K
Distributed systems, computer networks,
clock synchronization, multiprocess systems
.I 3083
.T
Pseudochaining in Hash Tables
.W
This paper presents pseudochaining as a new
collision-resolution method.  Pseudochaining is
half way between open addressing and chaining.  It owes
its name to the fact that link fields are present
in each cell of the hash table which permits "chaining"
of the first overflow items in the table.  The
efficiency of the method is derived and a tradeoff analysis is given.
.A
Halatsis, C.
Philokyprou, G.
.K
Hash code, scatter storage, open addressing, chaining,
pseudochaining, collision resolution, searching,
uniform probing.
.I 3084
.T
Interpolation Search -A Log LogN Search
.W
Interpolation search is a method of retrieving
a desired record by key in an ordered file by
using the value of the key and the statistical distribution
of the keys.  It is shown that on the average
log logN file accesses are required to retrieve a key,
assuming that the N keys are uniformly distributed.
 The number of extra accesses is also estimated and shown
to be very low.  The same holds if the cumulative
distribution function of the keys is known.  Computational
experiments confirm these results.
.A
Perl, Y.
Itai, A.
Avni, H.
.K
Average number of accesses, binary search, database,
interpolation search, retrieval, searching,
uniform distribution
.I 3085
.T
An O(n) Algorithm for Determining a Near-Optimal
Computation Order of Matrix Chain Products
.W
This paper discusses the computation of matrix
chain products of the form M1 x M2 x ... x Mn
where Mi's are matrices.  The order in which the matrices
are computed affects the number of operations.
 A sufficient condition about the association of the
matrices in the optimal order is presented.  An
O(n) algorithm to find an order of computation which
takes less than 25 percent longer than the optimal
time Topt is also presented.  In most cases, the algorithm
yields the optimal order or an order which
takes only a few percent longer than Topt (less than 1 percent on the average).
.A
Chin, F.Y.
.K
Approximate algorithm, heuristic algorithm,
matrix multiplication, matrix chain product
.I 3086
.T
On the Complexity of Computing the Measure of U[ai, bi]
.W
The decision tree complexity of computing the
measure of the union of n (possibly overlapping)
intervals is shown to be  (n log n), even if comparisons
between linear functions of the interval endpoints
are allowed.  The existence of an   (n log n) lower bound
to determine whether any two of n real numbers
are within   of each other is also demonstrated.  These
problems provide an excellent opportunity for
discussing the effects of the computational model on
the ease of analysis and on the results produced.
.A
Fredman, M.L.
Weide, B.
.K
Analysis of algorithms, combinatorial problems,
computational complexity, computational models,
decision tree programs, lower bounds
.I 3087
.T
An English Language Question Answering System
for a Large Relational Database
.W
By typing requests in English, casual users
will be able to obtain explicit answers from a
large relational database of aircraft flight and maintenance
data using a system called PLANES.  The
design and implementation of this system is described and
illustrated with detailed examples of the operation
of system components and examples of overall system
operation.  The language processing portion of the
system uses a number of augmented transition networks,
each of which matches phrases with a specific
meaning, along with context registers (his tory keepers)
and concept case frames; these are used for judging
meaningfulness of questions, generating dialogue for clarifying
partially understood questions, and resolving
ellipsis and pronoun reference problems.  Other system components
construct a formal query for the relational
database, and optimize the order of searching relations.
 Methods are discussed for handling vague or
complex questions and for providing browsing ability.
 Also included are discussions of important issues
in programming natural language systems for limited domains,
and the relationship of this system to others.
.A
Waltz, D.L.
.K
Question answering, relational database, natural language,
database front end, artificial intelligence,
dialogue, query generation, information retrieval, natural language programming
.I 3088
.T
General Equations for Idealized CPU-I/O Overlap Configurations
.W
General equations are derived for estimating
the maximum possible utilization of main storage
partitions, CPU and I/O devices under different conditions
in an idealized CPU-I/O overlap model of multiprogrammed
computer systems.  The equations are directly applicable
to any configuration consisting  of sets of
identical CPU's I/O processors, main storage partitions
and user tasks.  Examples are provided to illustrate
the use of the equations to compute effective processing
time per record and expected timesharing response
time under both balanced and unbalanced resource utilization conditions.
.A
Teory, T.J.
.K
Blocking, buffering, input/output, overlap, performance,
resource allocation, throughput, timesharing
.I 3089
.T
Performance of Rollback Recovery Systems under Intermittent Failures
.W
A mathematical model of a transaction-oriented
system under intermittent failures is proposed.
 The system is assumed to operate with a checkpointing
and rollback/recovery method to ensure reliable
information processing.  The model is used to derive the
principal performance measures, including availability,
response time, and the system saturation point.
.A
Gelenbe, E.
Derochette, D.
.K
Database reliability, file systems, checkpoints, recovery
procedures, checking techniques, reliability
and system performance evaluation
.I 3090
.T
Automated Welfare Client-Tracking and Service
Integration: The Political Economy of Computing
.W
The impacts of an automated client-tracking
system on the clients, caseworkers, administrators,
and operations of the welfare agencies that use it are
reported.  The major impact of this system was
to enhance the administrative  attractiveness of the
using agencies in the eyes of funders rather than
to increase their internal administrative efficiency.
This impact is a joint product of both the technical
features of the computer-based system and of the organizational
demands placed upon different agencies,
administrators, and caseworkers.  It illustrates the
way "successful" automated information systems fit
the political economies of the groups that use them.
.A
Kling, R.
.K
Social impacts of computing, organizational impacts
of computing, management information systems,
sociology of computing, information systems and
service integration, urban information systems
.I 3091
.T
Some Basic Determinants of Computer Programming Productivity
.W
The propose of this research was to examine
the relationship between processing characteristics
of programs and experience characteristics of programmers
and program development time.  The ultimate
objective was to develop a technique for predicting
the amount of time necessary to create a computer
program.  The fifteen program characteristics hypothesized
as being associated with an increase in programming
time required are objectively measurable from preprogramming
specifications.  The five programmer characteristics
are experience-related and are also measurable before a programming
task is begun.  Nine program characteristics
emerged as major influences on program development time,
each associated with increased program development
time.  All five programmer characteristics were found
to be related to reduced program development time.
 A multiple regression  equation which contained one programmer
characteristic and four program characteristics
gave evidence of good predictive power for
forecasting program development time.
.A
Chrysler, E.
.K
Programmer performance standards, predicting program
development time, program estimation techniques,
program development equation, value of programming experience,
programmer evaluation, programmer scheduling,
programmer productivity, programming management, Cobol programming
.I 3092
.T
Characteristics of Application Software Maintenance
.W
Maintenance and enhancement of application
software consume a major portion of the total life
cycle cost of a system.  Rough estimates of the total
systems and programming resources consumed range
as high as 75-80 percent in each category.  However,
the area has been given little attention in the
literature.  To analyze the problems in this area a
questionnaire was developed and pretested.  It was
then submitted to 120 organizations.  Respondents totaled
69.  Responses were analyzed with the SPSS
statistical package.  The results of the analysis indicate
that: (1) maintenance and enhancement do consume
much of the total resources of systems and programming
groups; (2) maintenance and enhancement tend to
be viewed by management as at least somewhat more important
than new application software development;
(3) in maintenance and enhancement, problems of a management
orientation tend to be more significant
than those of a technical orientation; and (4) user
demands for enhancements and extension constitute
the most important management problem area.
.A
Lientz, B.P.
Swanson, E.B.
Tompkins, G.E.
.K
Software maintenance, use of productivity
aids, management and technical issues
.I 3093
.T
Automatic Error Recovery for LR Parsers
.W
In this paper we present a scheme for detecting
and recovering from syntax errors in programs.
 The scheme, which is based on LR parsing, is driven
by information which is directly and automatically
obtainable from the information that is already present
in an LR parser.  The approach, which is patterned
after that of Levy and Graham and Rhodes, appears to
provide error recovery which is both simple and
powerful.
.A
Mickunas, M.D.
Modry, J.A.
.K
Programming languages, error correction, automatic
correction, parsing, LR, syntax errors, compilers
.I 3094
.T
Analyses of Deterministic Parsing Algorithms
.W
This paper describes an approach for determining
the minimum, maximum, and average times to
parse sentences acceptable by a deterministic parser.
 These quantities are presented in the form of
symbolic formulas, called time-formulas.  The variables
in these formulas represent not only the length
of the input string but also the time to perform elementary
operations such as pushing, popping, subscripting,
iterating, etc.  By binding to the  variables actual numerical
values corresponding to a given compiler-machine
configuration, one can determine the execution time
for that configuration.  Time-formulas are derived
by examining the grammar rules and the program representing
the algorithm one wishes to analyze.  The
approach is described by using a specific grammar that defines
simple arithmetic expressions.  Two deterministic
parsers are analyzed: a top-down recursive descent
LL(1) parser, and a bottom-up SLR(1) parser.  The
paper provides estimates for the relative efficiencies
of the two parsers.  The estimates applicable
to a specific machine, the PDP-10, are presented and
substantiated buy benchmarks.  Finally, the paper
illustrates the proposed approach by applying it to
the analyses of parsers for a simple programming
language.
.A
Cohen, J.
Roth, M.S.
.K
Syntactic analysis, analysis of algorithms,top-down
and bottom-up parsing, relative efficiencies.
.I 3095
.T
A Selective Traversal Algorithm for Binary Search Trees
.W
The problem of selecting data items from
a binary search tree according to a list of range
conditions is considered.  The process of visiting a
minimal number of nodes to retrieve data satisfying
the range conditions is called selective traversal.  Presented
in this paper is an algorithm for selective
traversal which uses a tag field for each node in the
tree.  The algorithm is particularly useful and
efficient when examination of data is more time
consuming than examination of a tag field.
.A
Driscoll, J.R.
Lien, Y.E.
.K
Data retrieval, range conditions, binary search
tree, tree traversal, selective traversal
.I 3096
.T
An Optimal Method for Deletion in One-Sided Height-Balanced Trees
.W
A one-sided height-balanced tree is a binary
tree in which every node's right subtree has a
height which is equal to or exactly one greater than the
height of its left subtree.  It has an advantage
over the more general AVL tree in that only one bit
of balancing information is required (two bits are
required for the ACL tree).  It is shown that deletion of
an arbitrary node of such a tree can be accomplished
in O(logn) operations, where n is the number of nodes
in the tree.  Moreover the method is optimal in
the sense that its complexity cannot be reduced in order
of magnitude.  This result, coupled with earlier
results by Hirschberg, indicates that, of the three basic
problems of insertion, deletion, and retrieval,
only insertion is adversely affected by this modification of an AVL tree.
.A
Zweben, S.H.
McDonald, M.A.
.K
Balanced, binary, search, trees
.I 3097
.T
Optimal Shift Strategy for a Block-Transfer CCD Memory
.W
For the purposes of this paper, a block-transfer
CCD memory is composed of serial shift registers
whose shift rate can vary, but which have a definite minimum
shift rate (the refresh rate) and a definite
maximum shift rate.  The bits iin the shift registers
are numbered 0 to N - 1, and blocks of N bits are
always transferred, always starting at bit 0.   What
is the best shift strategy so that a block transfer
request occurring at a random time will have to wait the
minimal amount of time before bit 0 can be reached?
 The minimum shift rate requirement does not allow one
to  simply "park" at bit 0 and wait for a transfer
request.  The optimal strategy involves shifting as slowly
as possible until bit 0 is passed, then shifting
as quickly as possible until a critical boundary is
reached, shortly before bit 0 comes around again.
 This is called the "hurry up and wait" strategy and is well
known outside the computer field.  The block-transfer
CCD memory can also be viewed as a paging drum
with a variable (bounded) rotation speed.
.A
Sites, R.L.
.K
Paging drum, charge coupled devices, shift register
memory, memory hierarchy, electronic drum,
latency
.I 3098
.T
Computer Generation of Gamma Random Variables
.W
A new method for generating random variables
from the gamma distribution with nonintegral shape
parameter a is proposed.  This method is similar to two
other methods recently given by Wallace and Fishman.
 It is compared with Fishman's and Ahrens and Dieter's methods.
 The core storage requirements and programming
effort for this method are similar to those of Fishman's
method.  The proposed method is the same as
Fishman's method for 1 < a < 2 and is faster than Fishman's
method for 3 < a < 19.  Also, the proposed
method is much simpler than Ahrens and Dieter's method and is faster for a < 8.
.A
Tadikamalla, P.R.
.K
Gamma variables, rejection method, computer methods
.I 3099
.T
New Sufficient Optimality Conditions for
Integer Programming and their Application
.W
The purpose of this report is to present a
new class of sufficient optimality conditions for
pure and mixed integer programming problems.  Some of
the sets of sufficient conditions presented can
be thought of as generalizations of optimality conditions
based on primal-dual complementarity in linear
programming.  These sufficient conditions are particularly
useful for the construction of difficult integer
programming problems with known optimal solutions.  These
problems may then be used to test and/or "benchmark"
integer programming codes.
.A
Fleisher, J.M.
Meyer, R.R.
.K
Integer programming, optimality conditions, test
problem construction, Kuhn-Tucker conditions,
greatest common divisor
.I 3100
.T
An Interference Matching Technique for Inducing Abstractions
.W
A method for inducing knowledge by abstraction
from a sequence of training examples is described.
 The proposed method, interference matching, induces abstractions
by finding relational properties common
to two or more exemplars.  Three tasks solved by a program
that uses an interference-matching algorithm
are presented.  Several problems concerning the description
of the training examples and the adequacy
of interference matching are discussed, and directions
for future research are considered.
.A
Hayes-Roth, F.
McDermott, J.
.K
Rule induction, knowledge acquisition, partial
matching, interference, graph matching, learning,
induction, knowledge representation, informal retrieval,
abstraction, generalization, language learning,
complexity, predicate discovery.
.I 3101
.T
The SL5 Procedure Mechanism
.W
This paper describes an integrated procedure
mechanism that permits procedures to be used as
recursive functions or as coroutines.  This integration
is accomplished by treating procedures and their
activation records (called environments) as data objects
and by decomposing procedure invocation into
three separate components at the source-language level.
 In addition, argument binding is under the control
of the programmer, permitting the definition of various
methods of argument transmission in the source
language itself.  The resulting procedure mechanism,which
is part of the SL5 programming language, is
well suited to goal-oriented problems and to other problems
that are more readily programmed by using
coroutines. Several examples are given.
.A
Hanson, D.
Griswold, R.E.
.K
Procedures, coroutines, programming languages,
interpreters, SNOBOL 4, backtracking
.I 3102
.T
Incorporation of Units into Programming Languages
.W
The issues of how a programming language might
aid in keeping track of physical units (feet,
sec, etc.) are discussed.  A method is given for the
introduction of relationships among units (a watt
is volts*amps, a yard is three feet) and subsequent automatic
conversion based upon these relationships.
 Various proposals for syntax are considered.
.A
Karr, M.
Loveman III, D.B.
.K
Units, language design, compiler construction, language syntax
.I 3103
.T
Automatic Data Structure Selection: An Example and Overview
.W
The use of several levels of abstraction has
proved to be very helpful in constructing and
maintaining programs.  When programs are designed with abstract
data types such as sets and lists, programmer
time can be saved by automating the process of filling
in low-level implementation details.  In the past,
programming systems have provided only a single general
purpose implementation for an abstract type.
 Thus the programs produced using abstract types were
then inefficient in space or time.  In this paper
a system for automatically choosing efficient implementations
for abstract types from a library of implementations
is discussed.  This process is discussed in detail for
an example program.  General issues in data structure
selection are also reviewed.
.A
Low, J.R.
.K
Abstract data types, automatic programming, data
structures, optimizing compilers, sets, lists
.I 3104
.T
Test Data as an Aid in Proving Program Correctness
.W
Proofs of program correctness tend to be long
and tedious, whereas testing, though useful in
detecting errors, usually does not guarantee correctness.
 This paper introduces a techniques whereby
test data can be used in proving program correctness.
 In addition to simplifying the process of proving
correctness, this method simplifies the process of providing
accurate specification for a program.  The
applicability of this technique to procedures
and recursive programs is demonstrated.
.A
Geller, M.
.K
Program verification, program testing, recursive programs
.I 3105
.T
A Language Extension for Expressing Constraints on Data Access
.W
Controlled sharing of information is needed and
desirable for many applications and is supported
in operating systems by access control mechanisms.  This
paper shows how to extend programming languages
to provide controlled sharing.  The extension permits
expression of access constraints on shared data.
 Access constraints can apply both to simple objects, and
to objects that are components of larger objects,
such as bank account records in a bank's data base.
 The constraints are stated declaratively, and can
be enforced by static checking similar to type checking.
 The approach can be used to extend any strongly-typed
language, but is particularly suitable for extending
languages that support the notion of abstract data
types.
.A
Jones, A.K.
Liskov,B.H.
.K
Programming languages, access control, data types,
abstract data types, type checking, capabilities
.I 3106
.T
A Fast Algorithm for Copying List Structures
.W
An algorithm is presented for copying an arbitrarily
linked list structure into a block of
contiguous storage locations without destroying  the original
list.  Apart from a fixed number of program
variables, no auxiliary storage, such as a stack, is used.
 The algorithm needs no mark bits and operates
in linear time.  It is shown to be significantly faster
than Fisher's algorithm, the fastest previous
linear-time algorithm for the same problem.  Its speed
comes mainly from its efficient list-traversal
technique, which folds the processing stack into the
structure being built, and from its classification
of list cells into nine types, which enables processing
operations to be optimized for each type.
.A
Clark, D.W.
.K
List copying, Lisp, space complexity, constant workspace
.I 3107
.T
Generating Beta Variates with Nonintegrel Shape Parameters
.W
A new rejection method is described for generating
beta variates.  The method is compared with
previously published methods both theoretically and through
computer timings.  It is suggested that the
method has advantages in both speed and programming
simplicity over previous methods, especially for
"difficult" combinations of parameter values.
.A
Cheng, R.C.H.
.K
Beta variates, random numbers, simulation
.I 3108
.T
Economical Encoding of Commas Between Strings
.W
A method for insertion of delimiters between
strings without using new symbols is presented.
 As the lengths of the strings increase, the extra cost,
in terms of prolongation, becomes vanishingly
small compared to the lengths of the strings.
.A
Even, S.
Rodeh, M.
.K
String transmission, delimiters, commas, encoding of the integers
.I 3109
.T
A Data Structure for Manipulating Priority Queues
.W
A data structure is described which can be used
for representing a collection of priority queues.
 The primitive operations are insertion, deletion,
union, update, and search for an item of earliest
priority.
.A
Vuillemin, J.
.K
Data structures, implementation of set operations,priority
queues, mergeable heaps, binary trees
.I 3110
.T
Assembling Code for Machines with Span-Dependent Instructions
.W
Many modern computers contain instructions
whose lengths depend on the distance from a given
instance of such an instruction to the operand of that
instruction.  This paper considers the problem
of minimizing the lengths of programs for such machines.
 An efficient solution is presented for the
case in which the operand of every such "span-dependent"
instruction is either a label or an assembly-time
expression of a certain restricted form.If this restriction
is relaxed by allowing these operands to
be more general assembly-time expressions, then
the problem is shown to be NP-complete.
.A
Szymanski, T.G.
.K
Span-dependent instructions, variable-length addressing,
code generation, assemblers, compilers,
NP-complete, computational complexity.
.I 3111
.T
Secure Communications Over Insecure Channels
.W
According to traditional conceptions of cryptographic
security, it is necessary to transmit
a key, by secret means, before encrypted messages can
be sent securely.  This paper shows that it is
possible to select a key over open communications channels
in such a fashion that communications security
can be maintained.  A method is described which forces
any enemy to expend an amount of work which increases
as the square of the work required of the two communicants
to select the key.  The method provides a
logically new kind of protection against the passive
eaves dropper.  It suggests that further research
on this topic will be highly rewarding, both
in a theoretical and a practical sense.
.A
Merkle, R.C.
.K
Security, cryptography, cryptology, communications
security, wiretap, computer network security,
passive eavesdropping, key distribution, public key cryptosystem
.I 3112
.T
List Processing in Real Time on a Serial Computer
.W
A real-time list processing system is one
in which the time required by the elementary list
operations (e.g. CONS, CAR, CDR, RPLACA, REPLACD, EQ,
and ATOM in LISP) is bounded by a (small) constant.
 Classical implementations of list processing systems
lack this property because allocating a list cell
from the heap may cause a garbage collection, which process
requires time proportional to the heap size
to finish.  A real-time list processing system is presented
which continuously reclaims garbage, including
directed cycles, while linearizing and compacting the
accessible cells into contiguous locations to avoid
fragmenting the free storage pool.  The program is small
and requires no time-sharing interrupts, making
it suitable for microcode.  Finally, the system requires
the same average time, and not more than twice
the space, of a classical implementation, and those
space requirements can be reduced to approximately
classical proportions by compact list representation.
 Arrays of different sizes, a program stack, and
hash linking are simple extensions to our system, and
reference counting is found to be inferior for
many applications.
.A
Baker, H.G.
.K
Real-time, compacting,garbage collection, list processing,
virtual memory, file or database management,
storage management, storage allocation, LISP, CDR-coding, reference counting.
.I 3113
.T
Optimal Conversion of Extended-Entry
Decision Tables with General Cost Criteria
.W
A general dynamic programming algorithm for converting
limited, extended, or mixed entry decision
tables to optimal decision trees is presented which can
take into account rule frequencies or probabilities,
minimum time and/or space cost criteria, common action
sets, compressed rules and ELSE rules, sequencing
constraints on condition tests, excludable combinations
of conditions, certain ambiguities, and interrupted
rule masking.
.A
Lew, A.
.K
Decision table, optimal programs, dynamic programming
.I 3114
.T
A Technique for Isolating Differences Between Files
.W
A simple algorithm is described for isolating
the differences between two files.  One application
is the comparing of two versions of a source program
or other file in order to display all differences.
 The algorithm isolates differences in a way that corresponds
closely to our intuitive notion of difference,
is easy to implement, and is computationally efficient,
with time linear in the file length.  For most
applications the algorithm isolates differences similar
to those isolated by the longest common subsequence.
 Another application of this algorithm merges files
containing independently generated changes into a
single file.  The algorithm can also be used to generate
efficient encodings of a file in the form of
the differences between itself and a given "datum" file,
permitting reconstruction of the original file
from the difference and datum files.
.A
Heckel, P.
.K
Difference isolation, word processing, text editing,
program maintenance, hash coding, file compression,
bandwidth compression, longest common subsequence,
file comparison, molecular evolution
.I 3115
.T
Orderly Enumeration of Nonsingular Binary
Matrices Applied to Text Encryption
.W
Nonsingular binary matrices of order N, i.e.,
nonsingular over the field {0, 1}, and an initial
segment of the natural numbers are placed in one-to-one
correspondence.  Each natural number corresponds
to two intermediate vectors.  These vectors are mapped into
a nonsingular binary matrix.  Examples of
complete enumeration of all 2 x 2 and 3 x 3 nonsingular
binary matrices were produced by mapping the
intermediate vectors to the matrices.  The mapping
has application to the Vernam encipherment method
using pseudorandom number sequences.  A bit string formed
form bytes of text of a data encryption key
can be used as a representation of a natural number.
This natural number is transformed to a nonsingular
binary matrix.  key leverage is obtained by using the
matrix as a"seed" in a shift register sequence
pseudorandom number generator.
.A
Payne, W.H.
McMillen, K.L.
.K
Binary matrices, combinatorics, combinations, nonsingular
matrices, encryption, Vernam, pseudorandom
numbers, feedback shiftregister sequences, random numbers.
.I 3116
.T
Interference Detection Among Solids and Surfaces
.W
In many industrial environments it is necessary to determine whether
r there is interference among components.  There are many potential
interference problems in products made up of assemblies of components
and in product manufacturing and testing.  Typically, drawings
are used in an attempt to detect such unwanted interferences,
but the two-dimensional, static drafting medium does not always show
interferences among three-dimensional, moving parts.  This paper
 presents a computer representation for solids and surfaces and algorithms
which carry out interference checking among objects so represented.
Objects are represented as polyhedra or as piecewise planar
surfaces.  Two types of interference checking are discussed:
detection of intersections among objects in fixed positions and detection
of collisions among objects moving along specified trajectories.
.A
Boyse, J.W.
.K
Interference checking, intersection detection, collision detection, solid
representation, polyhedral representation, graphics, polygons, surfaces
.I 3117
.T
The Impact and Use of Computer Technology by the Police
.W
Over the past decade there has been a significant growth
in the use of computer technology by U.S. police departments.  This
growth, however, has been at a slower rate than predicted in the
early 1970's.  Further, when computer applications extend
beyond "routine" uses to "nonroutine" efforts, such as resource allocation
or computer-aided-dispatch systems where the machine begins to become
a tool for decision making, strategic planning and person/machine
interaction, the results of the technology to date have been
mixed.  This paper reports on case studies and surveys which provinsights
on the implementation and impact of police computer technology
and the relationship of this technology to law enforcement and society.
.A
Colton, K.W.
.K
Computer technology, innovation, police resource allocation, police command
and control, computer aided dispatch,
law enforcement, technology transfer
.I 3118
.T
Permutation of Data Blocks in a Bubble Memory
.W
A common internal organization of bubble memories consists of a set of (minor)
loops, connected through another (major) loop.  The problem of obtaining any
give n permutation of the minor loop contents in minimum time is studied
in this paper.  A lower bound to the number of steps required buy
a permutation algorithm is derived, and the class of optimum algorithms is
identified.
.A
Bongiovanni, G.C.
Luccio, F.
.K
Bubble memory, memory loops, permutation algorithm, data block shift
.I 3119
.T
The Impact of Distributions and Disciplines
on Multiple Processor Systems
.W
Simple queueing models are used to study the performance tradeoffs of
multiple processor systems.  Issues considered include the impact of CPU
service disciplines and distributions, level of multiprogramming,
multitasking, and job priorities.
.A
Sauer, C.H.
Chandy, K.M.
.K
Multiprogramming, multiprocessing, scheduling disciplines,
performance evaluation, queueing models
.I 3120
.T
An Event-Driven Compiling Technique
.W
Due to the linear structure of source text, difficulties may arise in a
one-pass compilation process.  These difficulties occur when an entity
cannot be processed because of a forward reference to information
only obtainable from subsequent entities.  Classic solutions
ask for data structures appropriate for each case.  A technique is
presented here which uses instead control structures, namely events
and processes.  The work of the compiler-writer becomes easier both
conceptually and in practice because he can forget these problems
at the outset and he avoids special processing for each problem.
This technique has been applied to the construction of an Algol
68 compiler.  Three examples from that implementation
are described and discussed here.
.A
Banatre, J.P.
Routeau, J.P.
Trilling, L.
.K
Compiling technique, one-pass compilation, semantic
analysis, event, process, parallelism
categories--4.12
.I 3121
.T
Syntactic Source to Source Transforms and Program Manipulation
.W
Syntactic transforms are the source to source program transformations
which preserve the history of computation, and thus do not
modify the execution time.  Combined with a small number of primitive
semantic transforms, they provide a powerful tool for program
manipulation.  A catalogue of syntactic transforms, and its use for
solution of a system of program equations, is given.  Examples of
derivation of more complex source to source transformations are also
presented.  Two case studies illustrate the way in which syntactic
and semantic source to source transformations may be used for
development of clear, simple, and reasonably efficient programs.
.A
Arsac, J.J.
.K
Structured programming, program transforms, control structures
.I 3122
.T
Production and Employment of Ph.D.'s in Computer Science - 1977 and 1978
.A
Taulbee, O.E.
Conte, S.D.
.K
Computer science, production of Ph.D.'s, employment, students
.I 3123
.T
Employment Characteristics of Doctoral Level Computer Scientists
.A
Fairley, R.E.
.K
Employment characteristics, manpower utilization,occupational trends
.I 3124
.T
Recursive Data Structures in APL
.W
A mathematical study of three approaches for defining nested
arrays in APL is presented.  Theorems exhibiting the relationships
between the definitional systems are given and illustrated through graph
representations.  One of the approaches is used to define an
APL array to be a recursive data structure equivalent to a tree structure
in which all data is stored at the leaves as homogeneous
arrays of numbers and characters.  An extension of APL is proposed that
includes new primitive functions to manipulate the nesting
level of arrays and new operators to assist in the
construction of data-driven algorithms.
.A
Gull,W.E.
Jenkins, M.A.
.K
Nested arrays, APL arrays, recursive data structures,
trees, data-driven algorithms, theory of arrays
.I 3125
.T
Global Optimization by Suppression of Partial Redundancies
.W
The elimination of redundant computations and the moving of invariant
computations out of loops are often done separately, with invariants
moved outward loop by loop.  We propose to do both at once and
to move each expression directly to the entrance of the outermost
loop in which it is invariant.  This is done by solving a more
general problem, i.e. the elimination of computations performed
twice on a given execution path.  Such computations are termed partially
redundant.  Moreover, the algorithm does not require any graphical
information or restrictions on the shape of the program graph.
Testing this algorithm has shown that its execution cost is nearly
linear with the size of the program, and that it leads
to a smaller optimizer that requires less execution time.
.A
Morel, E.
Renvoise, C.
.K
Optimizer, optimization, compiler, compilation,
redundancy elimination, invariant
 computation elimination, partial redundancy,
data flow analysis, Boolean systems
.I 3126
.T
Comments on Perfect Hashing Functions: A Single
Probe Retrieving  Method for Static Sets
.A
Anderson, M.G.
.K
Hashing, hashing methods, hash coding, direct addressing, identifier-
to-address transformations, perfect hashing functions, perfect
hash coding, reduction, retrieving, scatter storage, searching
.I 3127
.T
Thoth, a Portable Real-Time Operating System
.W
Thoth isa real-time operating system which is designed to be portable
over a large set of machines.  It is currently running on two minicomputers
with quite different architectures.  Both the system and application
programs which use it are written in a high-level language.
Because the system is implemented by the same software on different
hardware, it has the same interface to user programs.  Hence,
application programs which use Thoth are  highly portable.  Thoth
encourages structuring programs as networks of communicating processes
by providing efficient interprocess communication primitives.
.A
Cheriton, D.R.
Malcolm, M.A.
Melen, L.A.
Sager, G.R.
.K
Portability, real time, operating systems, minicomputer
.I 3128
.T
Synchronization with Eventcounts and Sequencers
.W
Synchronization of concurrent processes requires controlling the relative
ordering of events in the processes.
A new synchronization mechanism is proposed, using
abstract objects called eventcounts and sequencers, that allows processes
to control the ordering of events directly, rather than using mutual
exclusion to protect manipulations of shared variables that control
ordering of events.  Direct control of ordering seems to simplify
correctness arguments and also simplifies implementation in distributed
systems.  The mechanism is defined formally, and then several
examples of its use are given.  The relationship of the mechanism
to protection mechanisms in the system is explained; in particular,
eventcounts are shown to be applicable to situations where confinement
of information matters.  An implementation of eventcount
s and sequencers in a system with shared memory is described.
.A
Reed, D.P.
Kanodia, R.K.
.K
Process synchronization, interprocess communication, distributed
systems, security models, mutual exclusion, semaphores
.I 3129
.T
Optimal Storage Allocation for Serial Files
.W
A computer system uses several serial files.  The files reside on a
direct-access storage device in which storage space is limited.  Records are
added to the files either by jobs in batch processing mode, or by on-line
transactions. Each transaction (or job) generates a demand vector which
designates the space required in each file for record addition. Whenever one
file runs out of space, the system must be reorganized.  This paper considers
several criteria for best allocating storage space to the files.
.A
Mendelson, H.
Pliskin, J.S.
Yechiali, U.
.K
Serial files, storage allocation, reorganization, partitioned dataset
.I 3130
.T
CURRICULUM '78 - Recommendations for the
Undergraduate Program in Computer Science
.W
Contained in this report are the recommendations for
the undergraduate degree program in Computer Science of the
Curriculum Committee on Computer Science (C3S) of the Association
for Computing Machinery (ACM).   The core curriculum common to all
computer science undergraduate programs is presented in terms of
elementary level topics and courses, and intermediate level courses.
Elective courses, used to round out an undergraduate program,
are then discussed, and the entire program including the computer
science component and other material is presented.  Issues related
to undergraduate computer science education, such as service
courses, supporting areas, continuing education, facilities,
staff, and articulation are presented.
.A
Austing, R.H.
Barnes, B.H.
Bonnette, D.T.
Engel, G.L.
Stokes, G.
.K
Computer sciences courses, computer science curriculum, computer
science education, computer science undergraduate degree
programs, service courses, continuing education
.I 3131
.T
FOCUS Microcomputer Number System
.W
FOCUS is a number system and supporting computational
algorithms especially useful for microcomputer control and other
signal processing applications.  FOCUS has the wide-ranging
character of floating-point numbers with a uniformity of state distributions
that give FOCUS better than a twofold accuracy advantage
over an equal word length floating-point system.  FOCUS computations
are typically five times faster than single precision fixed-point
or integer arithmetic for a mixture of operations, comparable in
speed with hardware arithmetic for many applications.  Algorithms
for 8-bit and 16-bit implementations of FOCUS are included.
.A
Edgar, A.D.
Lee, S.C.
.K
Number representation, logarithmic arithmetic, computational
speed, computational accuracy, microcomputer applications
.I 3132
.T
Experiments with Some Algorithms that Find
Central Solutions for Pattern Classification
.W
In two-class pattern recognition, it is a standard
technique to have an algorithm finding hyperplanes
which separates the two classes in a linearly separable training
set.  The traditional methods find a hyperplane which separates all
points in the other, but such a hyperplane is not necessarily centered
in the empty space between the two classes.  Since a central
hyperplane does not favor one class or the other, it should have
a lower error rate in classifying new points and is therefore better
than a noncentral hyperplane.  Six algorithms for finding central
hyperplanes are tested on three data sets.  Although frequently
used practice, the modified relaxation algorithm is very poor.
Three algorithms which are defined in the paper are found to be
quite good.
.A
Slagle, J.
.K
Pattern recognition, pattern classification, linear discriminants, central
hyperplanes, centering, centrality criteria, dead zone, hyperplane,
linearly separable, relaxation algorithm, accelerated relaxation
.I 3133
.T
Logic and Semantic Networks
.W
An extended form of semantic network is defined, which can
be regarded as a syntactic variant of the clausal form of logic.
By virtue of its relationship with logic, the extended
semantic network is provided with a precise semantics,
inference rules, and a procedural interpretation.  On
the other hand, by regarding semantic networks as an
abstract data structure for the representation of clauses, we provide a
theorem-prover with a potentially useful indexing scheme and path-following
strategy for guiding the search for a proof.
.A
Deliyanni, A.
Kowalski, R.A.
.K
Logic, semantic networks, theorem-proving, indexing, resolution, deduction,
logic programming
.I 3134
.T
The Use of Normal Multiplication Tables
for Information Storage and Retrieval
.W
This paper describes a method for the organization and retrieval of attribute
based information systems, using the normal multiplication table as a directory
for the information system.  Algorithms for the organization an
d retrieval of information are described.  This method is particularly
suitable for queries requesting a group of information items,
 all of which possess a particular set of attributes (and possibly
some other attributes as well).  Several examples are given; the
results with respect to the number of disk accesses and disk space
are compared to other common approaches.  Algorithms evaluating
the appropriateness of the above approach to a given information system
are described.  For a certain class of information systems,
the normal multiplication table method yields far more rapid retrieval
with a more economical space requirement than conventional systems.
Moreover this method incorporates an improved modification of the inverted
file technique.
.A
Motzkin, D.
.K
Information retrieval, inverted files, multiattribute retrieval,
multilist file, normal multiplication table, queries,
rapid retrieval, space economy
.I 3135
.T
Detection of Three-Dimensional Patterns of Atoms in Chemical Structures
.W
An algorithm for detecting occurrences of a three-dimensional pattern of
objects within a larger structure is presented.  The search technique
presented uses the geometric structure of the pattern to define
characteristics demanded of candidates for matching. This is useful
in cases where the properties of each atom, considered individually,
do not adequately limit the number of sets of possible matchings.
Several applications of this technique in the field of chemistry
are: (1) in pharmacology: searching for a common constellation
of atoms in molecules possessing similar biological activities;
(2) in X-ray crystallography: fitting a structure or a structural fragment
to a set of peaks in the electron-density distribution of
a Fourier map; (3) in chemical documentation; retrieving from
a file the structures containing specified substructures.
.A
Lesk, A.M.
.K
Three-dimensional pattern recognition, chemical
structure search, information retrieval, crystal
-structure analysis, drug analysis and design
.I 3136
.T
Price/Performance Patterns of U.S. Computer Systems
.W
Econometric models of the U.S. computer market have been developed to study
the relationships between system price and hardware performance.  Single
measures of price/performance such as "Grosch's Law" are shown to
be so over simplified as to be meaningless.  Multiple-regression models
predicting system cost as a function of several hardware
characteristics do, however, reveal a market dichotomy.  On one hand there
exists a stable, price predictable market for larger, general
purpose computer systems.  The other market is the developing one
for small business computer systems, a market which is relatively
unstable with low price predictability.
.A
Cale, E.G.
Gremillion, L.L.
McKenney, J.L.
.K
Price/performance, Grosch's law, U.S. computer market
.I 3137
.T
A Methodology for the Design of Distributed Information Systems
.W
A macro model of a distributed information system in presented.  The model
describes the major costs of using an information
system from the perspective of the end-user.  The making evident the effect of
various design and operating parameters on overall cost per transaction.
 The technique is illustrated by application to the design
of an interactive transaction processing system.
.A
Bucci, G.
Streeter, D.N.
.K
Distributed processing, system design, cost minimization, distributed
database, interactive computing, economic modeling, transaction processing
.I 3138
.T
A Mathematical Programming Updating Method Using Modified
Givens Transformations and Applied to LP Problems
.W
An efficient and numerically stable method is presented for the problem of
updating an orthogonal decomposition of a matrix of column (or row) vectors.
The fundamental idea is to add a column (or row) analogous
to adding an additional row of data in a linear least squares problem.
A column (or row) is dropped by a formal scaling with the
imaginary unit,  -1, followed by least squares addition of the column
(or row).  The elimination process for the procedure is successive
ssive application of the Givens transformation in modified (more efficient)
form.  These ideas are illustrated with an implementation
of the revised simplex method.  The algorithm is a general purpose
one that does not account for any particular structure or sparsity
in the equations.  Some suggested computational tests for determining
signs of various controlling parameters in the revised simplex
algorithm are mentioned.  A simple means of constructing
test cases and some sample computing times are presented.
.A
Hanson, R.J.
Wisniewski, J.A.
.K
Linear programming, numerical linear algebra, modified Givens transformations,
linear programming test cases
.I 3139
.T
New Methods to Color the Vertices of a Graph
.W
This paper describes efficient new heuristic
methods to color the vertices of a graph which rely
upon the comparison of the degrees and structure of a graph.  A method
is developed which is exact for bipartite graphs and is an
important part of heuristic procedures to find maximal cliques in general
graphs.  Finally an exact method is given which performs better
than the Randall-Brown algorithm and is able to color larger
graphs, and the new heuristic methods, the classical methods, and
the exact method are compared.
.A
Brelaz, D.
.K
NP-complete, graph structure, balancing, graph
coloring, scheduling, comparison of the methods
.I 3140
.T
Social Processes and Proofs of Theorems and Programs
.W
It is argued that formal verifications of
programs, no matter how obtained, will not play the
same key role in the development of computer science and software
engineering as proofs do in mathematics.  Furthermore the absence
of continuity, the inevitability of change, and the complexity of
specification of significantly many real programs make the form
al verification process difficult to justify and manage.  It is felt
that ease of formal verification should not dominate program
language design.
.A
De Millo, R.A.
Lipton, R.J.
Perlis, A.J.
.K
Formal mathematics, mathematical proofs,
program verification, program specification
.I 3141
.T
An Improved Algorithm for Decentralized Extrema-Finding
in Circular Configurations of Processes
.W
This note presents an improvement to LeLann's
algorithm for finding the largest (or smallest) of a set of uniquely
numbered processes arranged in a circle, in which no central
controller exists and the number of processes is not known a priori.
This decentralized algorithm uses a technique of selective
message extinction in order to achieve an average number of
message passes of order (n log n) rather than O(n2).
.A
Chang, E.
Roberts, R.
.K
Decentralized algorithms, distributed systems, operating systems
.I 3142
.T
Consumer Difficulties With Computerized Transactions:
An Empirical Investigation
.W
The prevalence with which errors may be encountered by the
end targets of a computerized process is assessed.  How many and
what type of errors occur?  How easily are they corrected?  What
is the reaction of consumers to errors-to a failure to correct
them?  What can be learned by designers of large management packages
from such data? Results show that with the present state of the
art, approximately 40 percent of individuals (or households) having
average contacts with different types of accounts experience one
or more errors per year.  Eighty percent relate to billing.  Attempts
to correct errors often turned out to be difficult and not always
successful. There appears to be some conflict between computer-using
organizations and their public.  Also the role of poor man
agement packages including poor software is indicated.  While most
management systems may be adequate, results of the survey raise
concerns about the timeliness and the number of designs of very
large linked program packages (as EFT for instance).
.A
Sterling, T.D.
.K
Errors, systems errors, billing errors, management systems, consumers
.I 3143
.T
Reasoning About Arrays
.W
A variety of concepts, laws, and notations are presented which facilitate
reasoning about arrays.  The basic concepts include intervals and their
partitions, functional restriction, images, pointwise extension of relations,
ordering, single-point variation of functions, various equivalence relations
for array values, and concatenation.  The effectiveness
of these ideas is illustrated by informal descriptions of
algorithms for binary search and merging, and by a short formal proof.
.A
Reynolds, J.C.
.K
Arrays, assertions, program proving, intervals, partitions, pointwise
extension, ordering, concatenation, binary search, merging
.I 3144
.T
A Model for and DIscussion of Multi-Interpreter Systems
.W
A multi-interpreter system is a system in which programs execute
by virtue of being interpreted by other programs, which themselves may
either be interpreted (i.e. nested interpreters) or run directly on
the host machine.  The model reveals the anatomy of interpreters
and how these differ from procedures, and exhibits links
to protection domains and multiprocessor architectures.
.A
Manthey, M.J.
.K
Interpreters, transfer-of-control, hierarchies
.I 3145
.T
An Implementation of Structured Walk-Throughs
in Teaching Cobol Programming
.W
The effectiveness of structured
walk-throughs in teaching introductory Cobol programming was empirically
assessed with a sample of 215 under-graduate business administration
majors.  Cobol proficiency was measured by a final examination
testing (a) knowledge of language rules, (b) ability to read
and debug a program, and (c) the ability to write a program.  Analysis
of multiple covariance was used to statistically adjust test
scores for age and conditional reasoning scores. The findings provide
empirical support for incorporating structured walk-throughs
into the programming learning process more effectively
develop student proficiency in writing Cobol programs.
.A
Lemos, R.S.
.K
Structured walk-throughs, Cobol programming, teaching
of programming, testing programming proficiency
.I 3146
.T
An Academic Program Providing Realistic Training in Software Engineering
.W
An academic program at Harvey Mudd College, called
the Clinic program, brings projects from industry on
 campus to be studied and solved by student teams.  The objective of
the Clinic is to provide students, working as small teams under
 careful faculty supervision, an opportunity to work on real world
problems of sufficient magnitude and complexity.  Under this program,
students can acquire essential skills of software engineering,
such as team work, software project management, software design
methodology, and communication skills, in a realistic environment.
Sample software projects undertaken by the Clinic are described.
 Experience so far has shown that the program is a viable
transition from an academic to industrial world.
.A
Busenberg, S.N.
Tam, W.C.
.K
Software engineering, software engineering education, software
projects, student teams, software engineering skills
.I 3147
.T
A Model for Automating File and Program Design in Business Application Systems
.W
This paper discusses a model for finding an efficient implementation of a
business application system whose logical specifications have been determined
in advance.  The model views file and program design as a problem
of systematically coordinating the configurations of datasets and
computations.  It uses a straight forward search technique to
determine aggregations of computations, aggregations of datasets, device,
organization, and key order for each data set, key order for
 each computation, and access method  for each dataset-computation
pair.  Although computational results are presented for a sample
problem involving 54 computations and 49 datasets, the main point of
the paper is that the underlying model works computationally an
d is simple enough to be adapted to many file design situations.
.A
Alter, S.
.K
System design, automatic programming, search
methods, system configurations, design choices
.I 3148
.T
High Level Programming for Distributed Computing
.W
Programming for distributed and other loosely coupled systems
is a problem of growing interest.  This paper describes an approach
to distributed computing at the level of general purpose programming
languages.  Based on primitive notions of module, message,
and transaction key, the methodology is shown to be independent
of particular languages and machines.  It appears to be useful for
programming a wide range of tasks.  This is part of an ambitious
program of development in advanced programming languages, and relations
with other aspects of the project are also discussed.
.A
Feldman, J.A.
.K
Distributed computing, modules, messages, assertions
.I 3149
.T
The Cyclic Order Property of Vertices as an Aid in Scene Analysis
.W
A cyclic-order property is defined for bodies bounded by smooth-curved faces.
The property is shown to be useful for analyzing pictures of such bodies,
particularly when the line data extracted from the pictures are imperfect.
This property augments previously known grammatical rules that
determine the existence of three-dimensional bodies corresponding
to given two-dimensional line-structure data.
.A
Shapira, R.
Freeman, H.
.K
Scene analysis, cyclic order, artificial intelligence,
three-dimensional reconstruction
, picture processing, computer graphics, pattern recognition.
.I 3150
.T
Beyond Programming Languages
.W
As computer technology matures, our growing ability to create large systems is
leading to basic changes in the nature of programming.  Current programming
language concepts will not be adequate for building and maintaining
systems of the complexity called for by the tasks we attempt.  Just
as high level languages enabled the programmer to escape from the
intricacies of a machine's order code, higher level programming systems
can provide the means to understand and manipulate complex
systems and components.  In order to develop such systems, we need
to shift our attention away from the detailed specification of
algorithms, towards the description of the properties of the packages
and objects with which we build.  This paper analyzes some of the
shortcomings of programming languages as they now exist,
and lays out some possible directions for future research.
.A
Winograd, T.
.K
Programming, programming languages, programming systems, systems development
.I 3151
.T
An Optimal Real-Time Algorithm for Planar Convex Hulls
.W
An algorithm is described for the construction in real-time of the
convex hull of a set of n points in the plane.   Using an appropriate data
structure, the algorithm constructs the convex hull by successive
updates, each taking time O(log n), thereby achieving a total
processing time O(n log n).
.A
Preparata, F.P.
.K
Computational geometry, convex hull, planar set of
points, real-time algorithms, on-line algorithms.
.I 3152
.T
Storage Reorganization Techniques for
Matrix Computation in a Paging Environment
.W
In order to multiply matrices while minimizing
the number of page fetches required, it is often more efficient to
reorganize the data into submatrix form and to use block multiplication
rather than to use the best known algorithms which leave the
matrices stored in row-(or column-)oriented form.  An efficient
method for accomplishing this reorganization is given.  This also
makes possible the derivation of an asymptotically better bound
for multiplication of matrices given in row-oriented form by adapting
the technique of Strassen to the reorganized data.  The reorganization/block
multiplication scheme is shown to be advantageous for
matrices and pages of realistic size; the Strassen adaptation is
not.  The former scheme is also shown to be advantageous even if
the transpose of one of the matrices is available at no additional cost.
.A
Fischer, P.C.
Probert, R.L.
.K
Matrix multiplication, paging, virtual memory,
data reorganization, pagination, transpose.
.I 3153
.T
The Control of Response Times in Multi-Class
Systems by Memory Allocations
.W
The possibility of giving different quality of service to jobs of different
classes by regulating their memory allocation is examined in
the context of a paged computer system.  Two parameterized algorithms
which partition the main memory between two classes of jobs are
considered.  Initially, a closed system consisting of a process
or and paging and file devices, with fixed numbers of jobs, is studied
to determine optimal degrees of multiprogramming and the proportion
of processor time devoted to each class.  Applying a decomposition
approach and treating the closed system as a single server,
the response times in an open system with external arrivals are
studied.  The object is to investigate the effect of the memory
alocation parameters on the expected response times under the two algorithms.
Numerical solutions and economical lower bounds for the
expected response times as functions of the control parameters
are obtained.  A way of applying the results to systems with more
than two job classes is indicated.
.A
Hine, J.H.
Mitrani, I.
Tsur, S.
.K
Queueing networks, paging, virtual memory, performance control
.I 3154
.T
Algorithm = Logic + Control
.W
An algorithm can be regarded as consisting of a logic component,
which specifies the knowledge to be used in solving problems,
and a control component, which determines the problem-solving
strategies by means of which that knowledge is used.  The logic component
determines the meaning of the algorithm whereas the control
component only affects its efficiency.  The efficiency of an
algorithm can often by improving the control component without changing
the logic of the algorithm.  We argue that computer programs would
be more often correct and more easily improved and modified if
their logic and control aspects were identified and separated in
the program text.
.A
Kowalski, R.
.K
Control language, logic programming, nonprocedural language, programming
methodology, program specification, relational data structures
.I 3155
.T
The Paradigms of Programming
.A
Floyd, R.W.
.I 3156
.T
Computing Connected Components on Parallel Computers
.W
We present a parallel algorithm which uses n2 processors to find the connected
components of an undirected graph with n vertices in time O(log2n).  An
O(log2n) time bound also can be achieved using only n$n/$log2n)) processors.
The algorithm can be used to find the transitive closure
of a symmetric Boolean matrix.  We assume that the processors have
access to a common memory.  Simultaneous access to the same location
is permitted for fetch instructions but not for store instructions.
.A
Hirschberg, D.S.
Chandra, A.K.
Sarwate, D.V.
.K
Graph theory, parallel processing, algorithms,
transitive closure, connected component
.I 3157
.T
Proving Termination with Multiset Orderings
.W
A common tool for proving the termination of programs is the well-founded
set, a set ordered in such a way as to admit no infinite descending sequences.
The basic approach is to find a termination function  that maps
the values of the program variables into some well-founded set,
such that the value of the termination function is repeatedly reduced
throughout the computation.  All too often, the termination functions required
are difficult to find and are of a complexity out
of proportion to the program under consideration. Multisets (bags)
over a given well-founded set S are sets that admit multiple occurrences
of elements taken from S.  The given ordering on S induces
an ordering on the finite multisets over S.  This multiset ordering
is shown to be well-founded.  The multiset ordering enables the
use of relatively simple and intuitive termination functions in otherwise
difficult termination proofs.  In particular, the multiset
ordering is used to prove the termination of production systems,
programs defined in terms of sets of rewriting rules.
.A
Dershowitz, N.
Manna, Z.
.K
Program correctness, program termination, program verification, well-founded
orderings, well-founded sets, multisets, bags, production systems,
term rewriting systems, tree replacement systems, reduction rules
.I 3158
.T
Secure Personal Computing in an Insecure Network
.W
A method for implementing secure personal computing in a network
with one or more central facilities is proposed.  The method employs a
public-key encryption device and hardware keys.  Each user is responsible
for his own security and need not rely on the security of
the central facility or the communication links.  A user can safely
store confidential files in the central facility or transmit confidential
data to other users on the network.
.A
Denning, D.E.
.K
Personal computing, security, privacy, networks, public-key encryption
.I 3159
.T
Further Remark on Stably Updating Mean and Standard Deviation Estimates
.A
Nelson, L.S.
.K
Mean, standard deviation
.I 3160
.T
Rejuvenating Experimental Computer Science
.W
This report is based on the results of an NSF sponsored
workshop held in Wasington, D.C. on November 2, 1978.  The co-authors of the
report are: Gordon Bell, Digital Equipment Corporation; Bernard A. Galler,
University of Michigan; Patricia Goldberg, IBM Corporation; John
Hamblen, University of Missouri at Rolla; Elliot Pinson, Bell Telephone
Laboratories; and Ivan Sutherland, California Institute of
Technology.  Also participating in the workshop were representatives
of NSF and other government agencies.  In addition to the authors,
a number of other people have contributed to the contents of this
report.  In preparation for the original workshop, all doctorate-granting
computer science departments in the nation were asked
for comments and suggestions on the problems of experimental computer science.
A version of the current report dated January 15 was circulated to these
departments and to a number of industrial and government groups for criticism.
The editors and authors of this final version gratefully acknowledge the
contribution of a large number of other people at all stages in the preparation
of the report.
$Note: Following this presentation of the report, there is a
position paper on the crisis in experimental computer
science written by the ACM Executive Committee.)
.A
Feldman, J.A.
Sutherland, W.R.
.I 3161
.T
An ACM Executive Committee Position on the Crisis
in Experimental Computer Science
.A
McCracken, D.D., CCP
Denning, P.J.
Brandin, D.H.
.I 3162
.T
On Improving the Worst Case Running Time
of the Boyer-Moore String Matching Algorithm
.W
It is shown how to modify the Boyer-Moore string matching algorithm so that
its worst case running time is linear even when multiple occurrences of the
pattern are present in the text.
.A
Galil, Z.
.K
Computational complexity, linear time, worst case, string matching, periodicity
.I 3163
.T
An Optimal Insertion Algorithm for One-Sided
Height-Balanced BInary Search Trees
.W
An algorithm for inserting an element into a one-sided height-balanced
(OSHB) binary search tree is presented.  The algorithm operates in time
O(log n), where n is the number of nodes in
the tree.  This represents an improvement over the best previous
ly known insertion algorithms of Hirschberg and Kosaraju, which require
time O(log 2n).  Moreover, the O(log n) complexity is optimal. Earlier
results have shown that deletion in such a structure can
also be performed in O(log n) time.  Thus the result of this paper
gives a negative answer to the question of whether such trees should
be the first examples of their kind, where deletion has a smaller time
complexity than insertion.  Furthermore, it can now be concluded
that insertion, deletion, and retrieval in OSHB trees can
be performed in the same time as the corresponding operations for
the more general AVL trees, to within a constant factor.  However,
the insertion and deletion algorithms for OSHB trees appear much
more complicated than the corresponding algorithms for AVL trees.
.A
Raiha,K.J.
Zweben, S.H.
.K
Insertion, one-sided height-balanced trees, height-balanced
trees, binary trees, search trees.
.I 3164
.T
Progressive Acyclic Digraphs-A Tool for Database Integrity
.W
A progressive acyclic digraph (PAD) algorithm accepts are requests and
maintains a graph in an acyclic state.  When a request creates a cycle,
nodes are, "detached" until the new are can be entered acyclically
This process is important in certain areas of database implementation
in which there are constraints on the permissible sequences
of actions. Two PAD algorithms are presented; one uses a simple
path matrix representation and the other uses a list with an
"artificial gradient."  Experiments suggest that for large N the second
is considerably faster, though both are asymptotically O(NR),
where N is the number of nodes and R is the expected number
of nodes reachable along paths from any given node.
.A
Hansen, W.J.
.K
List processing, data structures, topological sort,
acyclic digraph, database integrity, network, deadlock
.I 3165
.T
Approximation of Polygonal Maps by Cellular Maps
.W
The approximation of polygonal thematic maps by cellular
maps, an important operation in geographical data processing,
is analyzed.  The data organization used for representing the polygonal
maps is a widely used segment-based data structure, where class
labels identify the regions bordering each segment on either side.
The approximation algorithm presented operates on such an
organization, eliminating the need for the recognition of region boundaries.
Each segment is examined only once.  The versatility of
the new organization is further illustrated by the outline of algorithms
for area computation and point inclusion.  The algorithm is
applied to a set of soil maps converted to computer-readable
form by means of a coordinate digitizer.
.A
Nagy, G.
Wagle, S.G.
.K
Polygon maps, cellularization, gridding, geographic data structures,
computational geometry, computer cartography, automated cartography
.I 3166
.T
Computing Standard Deviations: Accuracy
.W
Four algorithms for the numerical computation
of the standard deviation of (unweighted) sampled data
are analyzed.  Two of the algorithms are well-known in the statistical
and computational literature; the other two are new algorithms
specifically intended for automatic computation.  Our discussion is
expository, with emphasis on reaching a suitable definition of
"accuracy."  Each of the four algorithms is analyzed for the conditions
under which it will be accurate.  We conclude that all four
algorithms will provide accurate answers for many problems, but two
of the algorithms, one new, one old, are substantially more accurate
on difficult problems than are the other two.
.A
Chan, T.F.
Lewis, J.G.
.K
Mean, standard deviation, least squares, updating
estimates, rounding error analysis, condition number.
.I 3167
.T
Updating Mean and Variance Estimates: An Improved Method
.W
A method of improved efficiency
is given for updating the mean and variance of weighted sampled data
when an additional data value is included in the set.  Evidence
is presented that the method is stable and at least
as accurate as the best existing updating method.
.A
West, D.H.D.
.K
Mean, standard deviation, variance, updating estimates, removing data
.I 3168
.T
Comment on "An Optimal Evaluation of Boolean
Expressions in an Online Query System."
.A
Laird, P.D.
.K
Query, Boolean expression, information retrieval, file organization
.I 3169
.T
Note on "An Optimal Evaluation of Boolean Expressions
in an Online Query System."
.A
Gudes, E.
Hoffman, A.
.K
Query, Boolean expression, optimal evaluation, information retrieval
.I 3170
.T
On the Proof of Correctness of a Calendar Program
.W
A formal specification is given for a simple calendar
program, and the derivation and proof of correctness of the program are
sketched.  The specification is easy to understand, and its correctness is
manifest to humans.
.A
Lamport, L.
.K
Program specification, program verification, inductive assertions
.I 3171
.T
Line Numbers Made Cheap
.W
A technique is described for run-time line number administration
to be used for implementations of high level languages.  Under suitable
circumstances, this method requires absolutely no overhead,
in either time or space, during execution of the program.
.A
Klint, P.
.K
Line number administration, diagnostic messages, abstract machine code
.I 3172
.T
An Algorithm for Planning Collision-Free
Paths Among Polyhedral Obstacles
.W
This paper describes a collision avoidance algorithm
for planning a safe path for a polyhedral object moving among
known polyhedral objects.  The algorithm transforms the obstacles
so that they represent the locus of forbidden positions for an arbitrary
reference point on the moving object.  A trajectory of this
reference point which avoids all forbidden regions is free of collisions.
Trajectories are found by searching a network which indicates, for each vertex
in the transformed obstacles, which other vertices can be reached safely.
.A
Lozano-Perez, T.
Wesley, M.A.
.K
Path finding, collision-free paths, polyhedral objects,
polyhedral obstacles, graph searching, growing objects
.I 3173
.T
A Psychology of Learning BASIC
.W
This paper addresses the question: What does a person know
following learning of BASIC programming?  Several underlying conceptual
structures are identified: (1) a transaction is an event that
occurs in the computer and involves some operation on some object
at some location, (2) a prestatement is a set of transactions corresponding
to a line of code, (3) chunks are frequently occurring
 configurations of prestatements corresponding to several lines of code.
.A
Mayer, R.E.
.K
BASIC, Learning, instruction
.I 3174
.T
Password Security: A Case History
.W
This paper describes the history of the design of the password
security scheme on a remotely accessed time-sharing system.
The present design was the result of countering observed attempts
to penetrate the system.  The result is a compromise between
extreme security and ease of use.
.A
Morris, R.
Thompson, K.
.K
Operating systems, passwords, computer security
.I 3175
.T
Breaking Substitution Ciphers Using a Relaxation Algorithm
.W
Substitution ciphers are codes in which each letter
of the alphabet has one fixed substitute, and the word divisions
do not change.  In this paper the problem of breaking substitution
ciphers is represented as a probabilistic labeling problem.
Every code letter is assigned probabilities of representing plain text
letters.  These probabilities are updated in parallel for all
code letters, using joint letter probabilities.  Iterating the updating
scheme results in improved estimates that finally lead to
breaking the cipher.  The method is applies successfully to two examples.
.A
Peleg, S.
Rosenfeld, A.
.K
Cryptography, substitution ciphers,
probabilistic classification, relaxation
.I 3176
.T
Storing a Sparse Table
.W
The problem of storing and searching large sparse tables is ubiquitous in
computer science.  The standard technique for storing such tables is
hashing, but hashing has poor worst-case performance.  We propose
a good worst-case method for storing a static table of n entries,
each an integer between 0 and N - 1.  The method requires 0(n) w
words of storage and allows O(logn N) access time.  Although our method
is a little complicated to use in practice, our analysis shows
why a simpler algorithm used for compressing LR parsing tables works so well.
.A
Tarjan, R.E.
Yao, A.C.C.
.K
Gaussian elimination, parsing, searching,
sparse matrix, table compression, table lookup
.I 3177
.T
How to Share a Secret
.W
In this paper we show how to divide data D into
n pieces in such a way that D is easily reconstructable from any
k pieces, but even complete knowledge of k - 1 pieces reveals
olutely no information about D.  This technique enables the construction
of robust key management schemes for cryptographic systems
that can function securely and reliably even when misfortunes destroy
half the pieces and security breaches expose all but one of the
remaining pieces.
.A
Shamir, A.
.K
Cryptography, key management, interpolation
.I 3178
.T
Introduction to the EFT Symposium
.A
Kling, R.
.I 3179
.T
Overview of the EFT Symposium
.W
It is increasingly recognized that large-scale technologies such as EFT
have the potential for aiding in the solution of current societal problems.
Yet, these technologies also generate problems.  This symposium
presents selected papers from a conference that sought to discover
what is currently known about EFT impacts in society
and what research is needed in the future.
.A
Kraemer, K.L.
Colton, K.W.
.K
EFT's, research agenda, conference results, public policy
.I 3180
.T
Costs of the Current U.S. Payments System
.W
Neither the banking industry nor
public policy makers have good information on the comparative costs
of alternative payment systems such as cash, checks, credit cards,
and EFT transactions.  As a result, EFT systems and services are
likely to be implemented without a valid assessment of whether they
are cost-justified, lst alone justified in terms of other criteria.
.A
Lipis, A.H.
.K
EFT's,payment system costs, payment system volumes
.I 3181
.T
Public Protection and Education with EFT
.W
Research has revealed the existence of widespread
misinformation and lack of knowledge about EFT among
business and government as well as consumers.  As a result, any effort
to stimulate meaningful public participation in decisions on
the introduction of EFT systems will require a coordinated educational
effort of considerable scale.  In addition, research has revealed
shortcomings in the present system for defining responsibilities,
liabilities, and avenues of recourse.  THis article presents
several possible alternatives for improving the current system, but
ongoing research is also needed to assure that actions taken will
be responsive to the changing environment and consumer needs.
.A
Long, R.H.
.K
Electronic funds transfer systems, consumer education, security
and fraud, privacy, system reliability, EFT ombudsman
.I 3182
.T
Vulnerabilities of EFTs to Intentionally Caused Losses
.W
The hypothesis that consumers
are provided greater accuracy and freedom from error and fraud with
electronic funds transfer systems (EFTs) is discussed in light
of the technical capabilities and potential of the computer to protect
against both accidentally and intentionally caused losses.
Although the nomenclature for business crimes remains the same as for
manual depository and other financial service systems - for example,
fraud, theft, embezzlement - the characteristics of the crimes
are new. The changes resulting from the accelerating use of EFTs and
its continual technological advances broaden the scope of security
issues to be examined.  Factors such as backup requirements,
regulatory and legislative actions, and economics give rise to
the urgency for immediate research into solutions for emerging
EFTs - related vulnerabilities.
.A
Parker, D.B.
.K
EFTs, computer abuse, crime, security, errors,
losses, positions of trust, legislation
.I 3183
.T
Policy, Values, and EFT Research: Anatomy of a Research Agenda
.W
There is an emerging recognition that EFT systems have the potential to
vastly alter the payment and fund transfer system in American society.
A number of forces and actors are involved in this evolution,
and the values vary significantly depending on individual and institutional
perspectives. These value conflicts are highlighted
in a six-part research agenda: technological issues in EFT, EFT impacts
on people, economic impact of EFT, regulation and control of
EFT, and evaluating and monitoring EFT systems.
.A
Kraemer, K.L.
Colton, K.W.
.K
EFTs, research agenda, value conflicts, impacts on people,
economic impacts, regulation and control, monitoring EFT
.I 3184
.T
   Revised Report on the Algorithmic Language ALGOL 60
.W
   The report gives a complete defining description of the international
algorithmic language ALGOL 60. This is a language suitable for expressing
a large class of numerical processes in a form sufficiently concise for
direct automatic translation into the language of programmed automatic
computers.
.A
Nuar, P.
.I 3185
.T
   The Humble Programmer
.W
   We shall do a much better programming job, provided that we approach the
task with a full appreciation if its tremendous difficulty, provided that we
stick to modest and elegant programming languages, provided that we respect
the intrinsic limitations of the human mind and approach the task as Very
Humble Programmers.
.A
Dijkstra, E. W.
.I 3186
.T
   GO TO Statement Considerd Harmful
.A
Dijkstra, E. W.
.K
go to statement, jump instruction, branch instruction, conditional clause,
repetitive clause, program intelligibility, program sequencing
.I 3187
.T
   Certification of Algorithm 271 (QUICKERSORT)
.W
   QUICKERSORT compiled and run without correction through the ALDEP translator
for the CDC 1604A. Comparison of average sorting items with other recently
published algorithms demonstrates QUICKERSORT's superior performance.
.A
Blair, C.R.
.I 3188
.T
   Semiotics and Programming Languages
.W
   I have based my paper on semiotics and its three dimension. I should insert
at this point that language has many aspects and that pragmatics, semantics and
syntactics do not necessary cover all of them. One can, however, project most
aspects into the three semiotic dimension and there seems to be a strong
tendency to do so today.
.A
Zemanek, H.
.I 3189
.T
   An Algebraic Compiler for the FORTRAN Assembly Program
.W
   An algebraic compiler has been written which may be added to the FORTRAN
Assembly Program. This compiler will expand all algebraic statements with the
following operations: addition, subtraction, multiplication and division. It
will compile multi-level expressions in floating-point arithmetic (this is
easily be revised to fixed-point).
.A
Stiegler, A. D.
.I 3190
.T
   Correction to Economies of Scale and the IBM System/360
.W
   On page 439, a "typical" instruction mix id discussed and the timing computed
as outlined in that page. Through an undetected programming error, the times and
the resulting regression equation are slightly in error.
.A
Solomon, M.B.
.I 3191
.T
   Generating Permutations by Nested Cycling
.W
   The purpose of this letter is two_fold: first to give due credit to the
Tompkins-Paige algorithm, and second to clarify a comment by Hill, CR Review
13891 on "Programs for Permutations".
.A
Langdon, Glen G.
.K
permutations
.I 3192
.T
The Lincoln Keyboard - a Typewriter Keyboard Designed
for Computers Input Flexibility
.W
   A new typewriter keyboard, for direct and punched paper tape computer input
will replace the usual commercial keyboard with 88 characters chosen for the
convenience  of programmers. The Lincoln Keyboard is expected to facilitate
the programming of algorithmic process and should allow considerable
flexibility in assembly and utility routines.
.A
Vanderburgh, A.
.I 3193
.T
.W
   Work is in progress on a formula coding technique allowing direct entry
into the computer of formulae typed on an 84 character Flexo-writer. This
Flexo-writer will be modified for automatic half-line advance and retract,
without carriage return, to permit completely general sub and superscripting.
.I 3194
.T
   A Non-heuristic Program for Proving Elementary Logical Theorems
.W
   The paper discusses problems involved in designing a device capable of
distinguishing among speech events that are normally recognized as different
by native speakers of a particular language. Parallels between these problems
and those of chemical analysis are pointed out.
.A
Dunham, B.
Fridshal, R.
Sward, G. L.
.I 3195
.T
   Reiteration of ACM Policy Toward Standardization
.W
   The periodic change in officers, chairman and editors which usually follows
as election occasionally results in a change in policy. In the case of this
department there is no radical change, but this is nevertheless the proper time
to reiterate ans underline ACM's policy with respect to standardization in the
computer area.
.A
Gorn, S.
.I 3196
.T
   The Reactive Typewriter Program
.W
   84-character keyboard including alphabetical upper and lower case for good
readability. If the machine is restricted to only a single case, the lower case
is preferred. The reactive typewriter should be portable. the reactive
typewriter should operate over any commercially used, dial-type telephone
(voice) or telegraph (Telex) line or over leased (nondial) telegraph lines
interchangeably.
.A
Mooers, C. N.
.I 3197
.T
   Structures of Standards-Processing Organizations in the Computer Area
.W
   In line with the ACM's policy statement [Comm. ACM 5 (Nov. 1962), 547-549],
the following organizational descriptions have been provided in order to
describe standardization activities pertinent to computers and information
processing.
.A
Gorn, S.
Bemer, R. W.
Green, J.
.I 3198
.T
   Microprogramming, Emulators and Programming Languages
.W
  The problem we have been concerned with is that of converting language to
action - or intellectual energy to mechanical energy. The medium that we use
for this purpose is language and therefore we are preoccupied with the subject
of language. In the areas of language investigation we have concentrated first
on formalizing syntax and then on semantics.
.A
Greem, J.
.I 3199
.T
   ALGEM - An Algebraic Manipulator
.W
   ALGEM is a package of subprograms written in Slip, FORTRAN IV and MAP 7094
II to manipulate algebraic expressions. Algem's basic algebraic operations are
additions, subtractions, multiplications, division and exponentiation. It is
capable of handling any number of single letter variables, variable exponents,
and of finding the highest common factor of two polynomials. Also included are
such functions as substitution, differentiation, determining coefficients of
specified variables, solving a linear equation, basic I/O routines plus other
special purpose and arithmetic routines. The major innovation of Algem over
other manipulators is the assignment of types to all expressions and the use
of a standard ordering procedure.
.A
Gotlieb, C. C.
Novak, R. J.
.I 3200
.T
   A FORMAC Program for the Solution of Linear Boundary and Initial Value
Problems
.W
  A computer program is described which has been developed for obtaining
approximate solutions to linear initial and boundary-value problems involving
differential equations. For each problem, input to the program includes:
   1. The equations (in symbolic form) to be satisfied  -  the differential
equations, equations describing auxiliary conditions such as boundary
conditions, etc.
   2. A numerical description of the regions in which each of the equations
are to be satisfied.
   3. Sets of functions (in symbolic form) to be used in linear combinations
to approximate the solution functions. Give the above input, the program
generates an approximation to the solutions of the specified problemm in terms
of the specified functions which is optimum in the least-squares sense.
.A
Cuthill, E.
.I 3201
.T
   Symbolic Manipulation of Poisson Series
.W
   Poisson series of three variables are manageable symbolically through as a
set of formal subroutines written partially in the IBM 7094 machine language,
but to be called in the FORTRAN language for use in Fortran  programs. An
effort has been made to supply those operations which are most required by
celestial mechanics. The routines are entirely self-contained subroutines
and require only standard Fortran input/output units 5 and 6; they are design
to avoid waste and overflow of core storage space.
.A
Danby, J.
Deprit, A.
Rom, A.
.I 3202
.T
   MANIP: A Computer System for Algebra and Analytic Differentiation
.W
   A mathematical expression to be operated upon is written in FORTRAN-like
notation and stored in the computer as a string of BCD characters with all
blanks removed. It may be as complicated as desired (parentheses nested without
restriction, etc.) so long as the entire expression (or any subsequent form)
does not exceed 5000 characters. The problemm of performing algebraic operations
and obtaining analytic derivatives was translated into that of identifying and
manipulating character sequences. Programs which resulted were written in
FORTRAN IV for a CDC 3600 and are discussed in detail.
.A
Bender, B.
.I 3203
.T
   GRAD Assistant - A Program for Symbolic Algebraic Manipulation and
Differentiation
.W
   The General Recursive Algebra and Differentiation Assistant (GRAD Assistant)
now under development is a set of LISP functions which symbolically manipulate
abd differentiate algebraic expressions. It is designed for use with problemms
in which a large amount of routine manipulation is to be done by a program
without human intervention. Thus, GRAD must recognize necessary simplifications
without external guidance. While some complicated expressions (notably ones
involving nested radicals and trigonometric functions) do not yield completely
to the present version, it has proved quite useful indeed.
.A
Fletcher, J. G.
.I 3204
.T
   An On-Line Program for Non-Numerical Algebra
.W
   The goal of this program is to make a step toward te design of an automated
mathematical assistant. Some requirements for such a program are: it must be
easy to access, and that the result must be obtained in a reasonably short
time. Accordingly the program is written for a time-shared computer. The Q-32
computer as System Development Corporation, Santa Monica, California, was
chosen because it also had a LISP 1.5 compiler. Programming and debugging was
done from a remote teletype console at Stanford University.
.A
Korsvold, K.