bluuebunny/crossref_metadata_2025 huggingface dataset:
Interval arithmetic determinant evaluation and its use in testing for a Chebyshev system
Authors: Smith Lyle B.
Published: July 2002

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 Hansen 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.
Exclusive simulation of activity in digital networks
Authors: Ulrich Ernst G.
Published: July 2002

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.
Chebyshev interpolation and quadrature formulas of very high degree
Authors: Salzer Herbert E.
Published: July 2002

All the zeros
x

2

m

,
i

,
i
= 1(1)2

m

, of the Chebyshev polynomials
T

2

m

(
x
),
m
= 0(1)
n
, are found recursively just by taking
n
2

n
-1

real square roots. For interpolation or integration of ƒ(
x
), given ƒ(
x

2

m

,
i

), only
x

2

m

,
i

is needed to calculate (a) the (2

m

- 1)-th degree Lagrange interpolation polynomial, and (b) the definite integral over [-1, 1], either with or without the weight function (1 -
x
2
)
-1/2
, the former being exact for ƒ(
x
) of degree 2

m
+1

- 1.
Plotting a function of three independent variables
Authors: Stineman Russell W.
Published: July 2002

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.
When your computer needs a lawyer
Authors: Banzhaf John F.
Published: July 2002

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 troublespots 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 regulations 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.
Algorithm 335: a set of basic input-output procedures
Authors: de Vogelaere R.
Published: July 2002

By means of the primitives
insymbol
,
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
out-channel
to provide information for simultaneous output to several channels is suggested. Interrelationship between the declared procedures is furnished in tabular form.
Standards: Accommodating standards and identification of programming languages
Authors: Mooers Calvin N.
Published: July 2002

The user public wants standardization and reliable identification of programming languages and related services. One way of achieving these goals is 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 within 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 useful applied to other programming languages and computer services.
Numerical analysis in a Ph.D. computer science program
Authors: Parter Seymour V.
Published: July 2002

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.
Digital computer determination of alpha source activity
Authors: Robbins Donald , Taylor W. E.
Published: July 2002

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.
“Structural connections” in formal languages
Authors: Irons E. T.
Published: July 2002

This paper defines the concept of “structural connection” in a mechanical language in an attempt to classify various formal languages according to the complexity of parsing structures on strings in the languages. Languages discussed vary in complexity from those with essentially no structure at all to languages which are self-defining. The relationship between some existing recognition techniques for several language classes is examined, as well as implications of language structure on the complexity of automatic recognizers.
Education: A general-purpose display processing and tutorial system
Authors: Engvold K. J. , Hughes J. L.
Published: July 2002

ADEPT (
A
D
isplay-
E
xpedited
P
rocessing and
T
utorial) 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.
Computer-usage accounting for generalized time-sharing systems
Authors: Rosenberg Arthur M.
Published: July 2002

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 method for comparing the internal operating speeds of computers
Authors: Raichelson Eugene , Collins George
Published: July 2002

First, a table of frequencies of various types of operations is prepared based on experience in similar applications or, perhaps, on actual counts if these are available. Table 1 shows such a frequency table. Next, the total weighted execution time for a given operation type is obtained by multiplying the time required for the operation by the frequency count. Finally, an “average” operation time is calculated by summing overall operation types and dividing by the sum of the frequency counts. Table 2 shows the computation for the IBM 7090.

Table 3 shows a comparison of average and relative speeds for several current computers for the particular application using the IBM 7090 as a reference base.
Talk—a high-level source language debugging technique with real-time data extraction
Authors: ver Steeg R. L.
Published: July 2002

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.
Characteristics of the FORTRAN CEP language
Authors: Mancino O. G.
Published: July 2002

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.
An executive system implemented as a finite-state automaton
Authors: Heistand Roy E.
Published: July 2002

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 online 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.
The organization of structured files
Authors: Dzubak B. J. , Warburton C. R.
Published: July 2002

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.
Dribble posting a master file
Authors: Head Robert V.
Published: July 2002

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.
More on extensible machines
Authors: Leonard Gene F. , Goodroe John R.
Published: July 2002

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.
Methods of numerical integration applied to a system having trivial function evaluations
Authors: Waters John
Published: July 2002

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-Nyström 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.
Some experiments in algebraic manipulation by computer
Authors: Lapidus Arnold , Goldstein Max
Published: July 2002

A set of subroutines to allow algebraic manipulations on the IBM 7094 computer has been written using a List Processor, SLIP.

A series of four problems of increasing difficulty were solved using these routines.
Remarks on simulation of Boolean functions
Authors: Dodd George G.
Published: July 2002

Recently M. Morris Mano presented a method for performing Boolean OR, AND and NOT operations by means of arithmetic and conditional transfer operations in a decimal computer lacking builtin logical instructions [1]. When
A
,
B
,
C
are variables whose defined value is 0 or 1 and
a
,
b
,
c
are the corresponding integer variables with values 0 or 1, his Boolean OR was defined by:

“The result of an OR operation of Boolean variables is the same as the arithmetic addition of the
a
,
b
,
c
integer variables after which the following test is made: (a) If the sum is equal to zero, the result is correct; (b) If the sum is larger than zero, the answer is 1.”
Symbolic factoring of polynomials in several variables
Authors: Jordan Dale E. , Clapp Lewis C. , Kain Richard Y.
Published: July 2002

An algorithm for finding the symbolic factors of a multivariate 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.
General time-varying systems error sensitivities program
Authors: Wilkins R. D.
Published: July 2002

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 from at execution time, eliminating the need for individualized programs, and presaging the further development of extremely general computer programs.
Tensor calculations on the computer
Authors: Walton John J.
Published: July 2002

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.
Man-machine communication via simplified English
Authors: Bennett Edward M. , Mayer Rollin P. , Bagley Philip R.
Published: July 2002

Two specific projects are in process as part of an advanced planning effort for the development of automated techniques for command and control.
A tape file merge pattern generator
Authors: Cooke William S.
Published: July 2002

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-eel file and two drives to each multiple-reel file.
The COBOL sorting verb
Authors: Paterson J. B.
Published: July 2002

The COBOL-61 specifications have recently been augmented with a number of extensions, one of which is a SORT verb. COBOL was designed initially for use in the processing of data-files stored on serially-accessed input-output devices. In applications of this general type of processing, the sorting of data files is frequently found to be necessary. Furthermore, it is often convenient and economical to carry out other operations at the same time, such as pre-editing or pre-selection of data records as they enter the sorting process, or editing, merging, or report preparation as the records emerge from the sort. It is a great convenience to the user to be able to express all of these operations in the same procedural language that he is using for his other data-processing applications, instead of having to use a sorting system in which first pass and last pass own coding must be expressed in some other language. Furthermore, COBOL itself is not well adapted to the writing of efficient sorting programs. Accordingly, a sort function appeared to be a very desirable addition to the COBOL specifications.
Operational compatability of systems—conventions
Authors: Ryckman George F.
Published: July 2002

This project is engaged in (a) a program of research into the application of the concepts and techniques of modern data processing to the design of mechanical parts, and (b) the further development of automatic programming systems for numerically controlled machine tools. The project is a cooperative venture between the Computer Applications Group of the Electronic Systems Laboratory and the Design and Graphics Division of the Mechanical Engineering Department, and is sponsored by the Manufacturing Methods Division of the USAF Air Material Command through Contract AF-33(600)-40604.
On a class of iteration formulas and some historical notes
Authors: Traub J. F.
Published: July 2002

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 Padé 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.
DESCRIPTRAN—automated descriptive geometry
Authors: Kliphardt Raymond A.
Published: July 2002

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.
An algorithm for equivalence declarations
Authors: Arden Bruce W. , Galler Bernard A. , Graham Robert M.
Published: July 2002

Many algebraic translators provide the programmer with a limited ability to allocate storage. Of course one of the most desirable features of these translators is the extent to which they remove the burden of storage allocation from the programmer. Nevertheless, there are situations in which one wishes to make certain vectors and arrays contiguous, coincident, or overlapping. This is made possible in FORTRAN by the use of COMMON and EQUIVALENCE statements, in MAD by the use of PROGRAM COMMON, ERASABLE, and EQUIVALENCE statements, etc.
Syntactic and semantic augments to ALGOL
Authors: Smith Joseph W.
Published: July 2002

The purpose of this paper is to propose a set of syntactic and semantic augments to ALGOL. The proposed extension are designed to facilitate the description of “string” manipulation in that language; they do not constitute a comprehensive language for symbol manipulation. Several such languages (LISP, IPL, …) already exist—many more will be designed and advantageously used in the future. It is felt that such languages belong in the repertoire of some language-system which contains a hierarchy of languages as well as nested “continua” of languages. In such systems, new languages may be embedded, appended, extracted at will. The fact that ALGOL is, implicitly, such a language-system seems to be only dimly recognized, even by designers. In any event, what is proposed in the sequel is not a language for symbol manipulation—qua language; but rather, a set of obvious extensions to the “algebraic-language” portion of ALGOL. To be sure, these extensions are complete in the sense that they are sufficient to describe symbol manipulations, but after all, the same statement holds for machine-language. Moreover, the extensions do not constitute a minimal set of primitives for string or symbol manipulations—in the sense that complementation, shifting, … are primitives for machine arithmetic. Such primitives are essential only to machine designers (including designers of “augmented machine”, the basic machine augmented by subroutines for arithmetics not included in the hardware); to append only such primitives to ALGOL is to visit the omissive sins of the machine designers upon the users of ALGOL.
Programmed methods for printer graphical output
Authors: Garfinkel David
Published: July 2002

It is frequently desirable to display the results of computation in a graphical form. This is often done through the use of special hardware such as digital
X
,
Y
-plotters. Programmed graphical output for standard printers is preferable in several situations: (1) when economic considerations do not justify the expense of special hardware for the purpose, (2) when a combination of graphical output with some other kind, such as explanatory material, is desired, and (3) when some special variety of graphical output is needed which cannot readily be drawn by an analog device.

A number of routines have been prepared (primarily by users rather than manufacturers) to convert numerical data into graphical form for printing by output typewriters or line printers. Virtually nothing on this subject has been published, and this report represents an admittedly incomplete attempt to describe this technique and suggest possibilities for its use.
Self-adjusting binary search trees
Authors: Sleator Daniel Dominic , Tarjan Robert Endre
Published: July 2002

The
splay
tree, a self-adjusting form of binary search tree, is developed and analyzed. The binary search tree is a data structure for representing tables and lists so that accessing, inserting, and deleting items is easy. On an
n
-node splay tree, all the standard search tree operations have an amortized time bound of
O
(log
n
) per operation, where by “amortized time” is meant the time per operation averaged over a worst-case sequence of operations. Thus splay trees are as efficient as balanced trees when total running time is the measure of interest. In addition, for sufficiently long access sequences, splay trees are as efficient, to within a constant factor, as static optimum search trees. The efficiency of splay trees comes not from an explicit structural constraint, as with balanced trees, but from applying a simple restructuring heuristic, called
splaying
, whenever the tree is accessed. Extensions of splaying give simplified forms of two other data structures: lexicographic or multidimensional search trees and link/cut trees.
Introducing redundant computations in RTL data paths for reducing BIST resources
Authors: Parulkar Ishwar , Gupta Sandeep K. , Breuer Melvin A.
Published: July 2002

The need for considering BIST requirements during the scheduling and
assignment stages of behavioral synthesis has been demonstrated in previous research and techniques for reducing BIST resources of a data path during these stages of synthesis have been developed. However, the degree of freedom that can be exploited during scheduling and assignment to minimize these resources is often limited by the data and control dependencies of a behavior. In this paper, we propose transformation of a behavior before scheduling and assignment, namely introducing redundant computations such that the resulting data path is testable using few BIST resources. The transformation makes use of
spare capacity
of modules to add redundancy that enables test paths to be shared among the modules. A technique for identifying potential BIST resource sharing problems in a behavior and resolving them by redundant computations is presented. Introduiction of redundant computations is performed without compromising the latency and functional resource requirement of the behavior.
Smooth patching of refined triangulations
Authors: Peters Jorg
Published: July 2002

This paper presents a simple algorithm for associating a smooth, low-degree polynomial surface with triangulations whose extraordinary mesh nodes are separated by sufficiently many ordinary, 6-valent mesh nodes. Output surfaces are at least tangent continuous and are
C
2
sufficiently far away from extraordinary mesh nodes; they consist of three-sided Bézier patches of degree 4. In particular, the algorithm can be used to skin a mesh generated by a few steps of Loop's generalization of three-direction box-spline subdivision.
Comments on batched searching of sequential and tree-structured files
Authors: Piwowarski Marek
Published: July 2002

Exact formulas for the expected cost savings from batching requests against two types of j-ary trees are given. Approximate expressions are also presented.
Transient exponential-Erlang queues and steady-state simulation
Authors: Kelton W. David
Published: July 2002

The transient probabilistic structure of M/E
m
/1 and E
m
/M/1 queues initialized in an arbitrary deterministic state is derived in discrete time. Computational algorithms for obtaining the required probabilities are provided, and their application in calculating a variety of system performance measures is illustrated. The results are used to investigate the question of initializing simulations of systems such as these to promote rapid convergence to steady state, if that is the object of the simulation. These results are consistent with earlier studies for transient queueing systems, such as the M/M/s, but allow greater flexibility in specification of interarrival or service-time models inherent in the Erlang distributions.
Self-assessment procedure XVIII: fundamentals of data communications
Authors: Munson John C.
Published: July 2002

A self-assessment procedure dealing with the fundamentals of data communications
MIS careers—a theoretical perspective
Authors: Ginzberg Michael J. , Baroudi Jack J.
Published: July 2002

MIS personnel historically have exhibited a disturbingly high rate of turnover, and the job of the MIS manager is increasingly oriented to personnel and staffing problems. The MIS careers literature consistently suggests that what is needed to improve this situation is (1) more attention to formal career planning, and (2) the implementation of a dual career ladder system within the DP/IS organization. A look at the broader literature on organizational careers suggests that these suggestions may not in fact make sense. By considering only a subset of the relevant concepts about careers, we have reached conclusions that are quite possibly erroneous, and have made suggestions that will not likely help. Until further research on MIS personnel and their career needs is accomplished, we will have no valid basis for prescribing solutions to MIS careers problems. Suggestions for needed research are outlined.
Security without identification: transaction systems to make big brother obsolete
Authors: Chaum David
Published: July 2002

The large-scale automated transaction systems of the near future can be designed to protect the privacy and maintain the security of both individuals and organizations.
Algorithm 664
Authors: Schrauf Géza
Published: July 2002

A FORTRAN 77 implementation of a Gauss algorithm with partial pivoting for banded matrices is described. The algorithm keeps only part of the matrix that is necessary for the actual computation in memory. This allows large systems to be solved on machine without virtual memory, or if the virtual memory is too small for the problem.
Fast algorithms for
N
-dimensional restrictions of hard problems
Authors: Meyer auf der Heide Friedhelm
Published: July 2002

Let
M
be a parallel RAM with
p
processors and arithmetic operations addition and subtraction recognizing
L ⊂ N

n

in
T
steps. (Inputs for
M
are given integer by integer, not bit by bit.) Then
L
can be recognized by a (sequential) linear search algorithm (LSA) in
O
(
n
4
(log(
n
) +
T
+ log(
p
))) steps. Thus many
n
-dimensional restrictions of NP-complete problems (binary programming, traveling salesman problem, etc.) and even that of the uniquely optimum traveling salesman problem, which is Δ

P

2
-complete, can be solved in polynomial time by an LSA. This result generalizes the construction of a polynomial LSA for the
n
-dimensional restriction of the knapsack problem previously shown by the author, and destroys the hope of proving nonpolynomial lower bounds on LSAs for any problem that can be recognized by a PRAM as above with 2

poly(
n
)

processors in poly(
n
) time.
The reduction of perturbed Markov generators
Authors: Rohlicek Jan Robin , Willsky Alan S.
Published: July 2002

A new algorithm for the hierarchical aggregation of singularly perturbed finite-state Markov processes is derived. The approach taken bridges the gap between conceptually simple results for a relatively restricted class of processes and the significantly more complex results for the general case. The critical role played by (almost) transient states is exposed, resulting in a straightforward algorithm for the construction of a sequence of aggregate generators associated with various time scales. These generators together provide a uniform asymptotic approximation of the original probability transition function.
Knowledge-based tools to promote shared goals and terminology between interface designers
Authors: Neches Robert
Published: July 2002

Two tools that support cooperation are described: one for the construction of consistent and principled human-computer interfaces and the other for the construction of AI knowledge bases. These tools provide a central repository for design knowledge that otherwise would not be easily shared among users. The AI knowledge representation technology upon which the tools are founded is first described. A knowledge-based approach to interface construction is discussed, and how that approach applies to detecting design conflicts and inconsistencies stemming from two different kinds of team communication failure is illustrated. Next, a knowledge acquisition aid that is utilized within the interface construction paradigm and that also illustrates the same approach to supporting cooperative work is described. Finally, four sources of difficulty in team design efforts, which this approach seeks to address, are reviewed.
Productivity trends in certain office-intensive sectors of the U.S. Federal Government
Authors: Panko Raymond R.
Published: July 2002

It is often said that office productivity is virtually stagnant, increasing only about 4 percent every 10 years. The methodology used to estimate this 4 percent figure is examined and found to be inaccurate! There is no known way to estimate
overall
national office productivity trends. Productivity trends in a
single
part of the economy, however, can be examined, namely, office-intensive sectors of the U.S. federal government. Productivity in these sectors is found to be anything but stagnant, having increased 1.7 percent
annually
from 1967 to 1981 and 3.0 percent annually from 1977 through 1981.
Learning by doing with simulated intelligent help
Authors: Carroll John , Aaronson Amy
Published: July 2002

Intelligent advisory interfaces will afford new approaches to help and training problems, however little is known about the usability of such facilities. This recent study indicates that although intelligent help can support users, there are also specific potential problems.
The number of buffers required for sequential processing of a disk file
Authors: Itai Alon , Raz Yoav
Published: July 2002

The number of buffers required for sequential processing of disk files is investigated with the assumption that there is a single user served by two processors: one reads blocks from the disk into buffers in main memory, while the other processor processes the buffers. If processing is faster than reading, then two buffers suffice. However, if processing is slower, using only two buffers does not guarantee minimum completion time. The minimal required number of buffers is calculated in this article.
Scaling question answering to the web
Authors: Kwok Cody , Etzioni Oren , Weld Daniel S.
Published: July 2002

The wealth of information on the web makes it an attractive resource for seeking quick answers to simple, factual questions such as “who was the first American in space?” or “what is the second tallest mountain in the world?” Yet today's most advanced web search services (e.g., Google and AskJeeves) make it surprisingly tedious to locate answers to such questions. In this paper, we extend question-answering techniques, first studied in the information retrieval literature, to the web and experimentally evaluate their performance.First we introduce Mulder, which we believe to be the first general-purpose, fully-automated question-answering system available on the web. Second, we describe Mulder's architecture, which relies on multiple search-engine queries, natural-language parsing, and a novel voting procedure to yield reliable answers coupled with high recall. Finally, we compare Mulder's performance to that of Google and AskJeeves on questions drawn from the TREC-8 question answering track. We find that Mulder's recall is more than a factor of three higher than that of AskJeeves. In addition, we find that Google requires 6.6 times as much user effort to achieve the same level of recall as Mulder.
What's next in high-performance computing?
Authors: Bell Gordon , Gray Jim
Published: July 2002

We can trace the evolution from Crays, to clusters, to supercomputing centers. But where does it go from here?
Rights and responsibilities in ACM publishing
Authors: Snodgrass Richard Thomas
Published: July 2002

Progress on ACM's Becoming the Preferred Publisher
Trust, authenticity, and discursive power in cyberspace
Authors: Mitra Ananda
Published: July 2002

Immersed in a time warp, space is constantly being redefined.
Monotonic reductions, representative equivalence, and compilation of intractable problems
Authors: Liberatore Paolo
Published: July 2002

The idea of preprocessing part of the input of a problem in order to improve efficiency has been employed by several researchers in several areas of computer science. In this article, we show sufficient conditions to prove that an intractable problem cannot be efficiently solved even allowing an exponentially long preprocessing phase. The generality of such conditions is shown by applying them to various problems coming from different fields. While the results may seem to discourage the use of compilation, we present some evidence that such negative results are useful in practice.
An efficient register optimization algorithm for high-level synthesis from hierarchical behavioral specifications
Authors: Vemuri Ranga , Katkoori Srinivas , Kaul Meenakshi , Roy Jay
Published: July 2002

We address the problem of register optimization that arises during high-level synthesis from modular hierarchical behavioral specifications. Register optimization is the process of grouping carriers such that each group can be safely allocated to a hardware register. Global register optimization by inline expansion involves flattening the module hierarchy and using a heuristic register optimization procedure on the flattened description. Although inline expansion yields a near-optimal number of registers, it is very time consuming due to the large number of carrier compatibility relationships that must be considered. We present an efficient register optimization algorithm that achieves nearly the same effect of inline expansion without actually inline expanding. The distinguishing feature of the proposed algorithm is that it employs a hierarchical optimization phase which effectively exploits the properties of the module call graph and information gathered during local carrier lifecycle analysis of each module. Experimental results on a number of benchmarks show that the proposed algorithm produces nearly the same number of registers as inline expansion based global optimization and is faster by a factor of 7.0.
University of Melbourne
Authors: Howard Steve
Published: July 2002

The Interaction Design Group is a research group within the Department of Information Systems at the
University of Melbourne
. The department offers a Master of Information Systems degree (with a large component of interaction design) and a doctoral program in information systems, in which students can concentrate on interaction design and usability. Founded in 1853, the University of Melbourne is Australia's premier research-oriented university.
Accenture
Authors: Perrine Cynthia L. , Tar Jeffry J. , Asper Alan E.
Published: July 2002

Accenture
is the world's leading provider of management and technology consulting services and solutions. We help our clients identify and capitalize on their most important business and technology opportunities, and we provide solutions to their most critical challenges. Our approach is to create value for clients through our network of businesses by leveraging our industry knowledge, service-offering expertise, and insight into and access to emerging technologies.
Syntagm
Authors: Hudson William
Published: July 2002

Syntagm
(pronounced "sintam") is a small, Oxford-based consultancy providing user-centered design services, including new product development, prototyping, usability evaluation, usability testing and accessibility (see Figure 1). Customers have included Reuters, Digital Equipment Company, Dorling-Kindersley Multimedia, Xerox UK, and the Oxford Metrics Group.
SRA, NAIST & JST
Authors: Nakakoji Kumiyo , Yamamoto Yasuhiro , Atsushi Aoki
Published: July 2002

SRA Inc.
is an independent software development company in Japan with approximately 1,400 employees. SRA Key Technology Laboratory is a subsidiary company of SRA Inc., dedicated to research and consultation, with about 30 people, headed by Kouichi Kishida. SRA-KTL is well known for its uniquely innovative research projects supported by the government; this is unusual because many government-supported research institutes are much larger corporations.
Nara Institute of Science and Technology
is a national university consisting of three graduate schools, one of which is the Graduate School of Information Science. The school has a Cognitive Science laboratory, with which SRA-KTL has been collaborating for the last several years.
Japan Science and Technology Corporation
is a governmental organization that supports advanced and creative research in Japan. Its PRESTO (Precursory Research for Embryonic Science and Technology) program has been financially supporting this project for the last two years.
SQR
Authors: Guersenzvaig Ariel
Published: July 2002

SQR
is a Web design and development firm focusing on creating fulfilling user experiences. Our diverse clients include academic and cultural institutions, several Dutch banks, book publishers, large global firms, and Holland's most visited museum, The Van Gogh Museum, among others.
Anonymity on the Internet: why the price may be too high
Authors: Davenport David
Published: July 2002

By allowing anonymous Net communication, the fabric of our society is at risk.
Building efficient and effective metasearch engines
Authors: Meng Weiyi , Yu Clement , Liu King-Lup
Published: July 2002

Frequently a user's information needs are stored in the databases of multiple search engines. It is inconvenient and inefficient for an ordinary user to invoke multiple search engines and identify useful documents from the returned results. To support unified access to multiple search engines, a metasearch engine can be constructed. When a metasearch engine receives a query from a user, it invokes the underlying search engines to retrieve useful information for the user. Metasearch engines have other benefits as a search tool such as increasing the search coverage of the Web and improving the scalability of the search. In this article, we survey techniques that have been proposed to tackle several underlying challenges for building a good metasearch engine. Among the main challenges, the database selection problem is to identify search engines that are likely to return useful documents to a given query. The document selection problem is to determine what documents to retrieve from each identified search engine. The result merging problem is to combine the documents returned from multiple search engines. We will also point out some problems that need to be further researched.
Inside job
Authors: Quigley Ann
Published: July 2002

Ex-employees and trusted partners may pose the greatest threats to network security
Complete logical routings in computer mail systems
Authors: Martin P. , Tsichritzis D.
Published: July 2002

The
logical routing
of a message in a computer mail system involves the identification and location of the set of intended recipients for that message. This function is carried out by the naming and addressing mechanism of the mail system. An important property of that mechanism is that it should be able to identify and locate all the intended recipients of a message, so that, once submitted, a message will not become lost or stuck in the system. We first discuss
message addressing schemes
, which are a framework for dealing with the naming and addressing problem. Message addressing schemes can also serve as a basis for the analysis of some of the properties of logical message routing within a system. We examine the conditions necessary for a
complete
message addressing scheme, that is, one that guarantees to deliver all possible messages.
Andrew: a distributed personal computing environment
Authors: Morris James H. , Satyanarayanan Mahadev , Conner Michael H. , Howard John H. , Rosenthal David S. , Smith F. Donelson
Published: July 2002

The Information Technology Center (ITC), a collaborative effort between IBM and Carnegie-Mellon University, is in the process of creating Andrew, a prototype computing and communication system for universities. This article traces the origins of Andrew, discusses its goals and strategies, and gives an overview of the current status of its implementation and usage.
A note on undetected typing errors
Authors: Peterson James L.
Published: July 2002

Although human proofreading is still necessary, small, topic-specific word lists in spelling programs will minimize the occurrence of undetected typing errors.
Communications design for Co-oP: a group decision support system
Authors: Bui Tung X. , Jarke Matthias
Published: July 2002

Decision Support Systems (DSSs), computer-based systems intended to assist managers in preparing and analyzing decisions, have been single-user systems for most of the past decade. Only recently has DSS research begun to study the implications of the fact that most complex managerial decisions involve multiple decision makers and analysts. A number of tools for facilitating group decisions have been proposed under the label Group Decision Support Systems (GDSSs).

One of the most important functions of a GDSS is to provide problem-oriented services for communication among decision makers. On the basis of an analysis of the communication requirements in various group decision settings, this paper presents an architecture for defining and enforcing dynamic application-level protocols that organize decision group interaction. The architecture has been implemented on a network of personal computers in Co-oP, a GDSS for cooperative group decision making based on interactive, multiple-criteria decision methods.
Benchmarks for LAN performance evaluation
Authors: Press L.
Published: July 2002

A technique for quickly benchmarking the performance of local area networks (LANs) is presented. Programs which model both intermittent and constant network activity are given.
Set query optimization in distributed database systems
Authors: Gavish Bezalel , Segev Arie
Published: July 2002

This paper addresses the problem of optimizing queries that involve set operations (set queries) in a distributed relational database system. A particular emphasis is put on the optimization of such queries in horizontally partitioned database systems. A mathematical programming model of the set query problem is developed and its NP-completeness is proved. Solution procedures are proposed and computational results presented. One of the main results of the computational experiments is that, for many queries, the solution procedures are not sensitive to errors in estimating the size of results of set operations.
Self-assessment procedure XIX
Authors: Bickel R. W.
Published: July 2002

A self-assessment procedure on the application of copyright law to computer programs
Why the look and feel of software user interfaces should not be protected by copyright law
Authors: Samuelson P.
Published: July 2002

An attorney looks at how copyright law is applied to the protection of software user interfaces and makes a strong case for reevaluating the way the law views software.