ppxscal/embedding_network huggingface dataset:
Relating software requirements and design
Authors: Lawrence Peters
Venue: ACM SIGSOFT Software Engineering Notes (1978)

Software development is a process which has evolved into a number of phases. Although the names of the phases and some of their characteristics differ from contractor to contractor and customer to customer, the functional similarities among sets of phases cannot be ignored. The basic software development scenario depicted by these phases starts with problem identification and definition, requirements specification, design, code, test, and installation and maintenance. Although some &ldquo;smearing&rdquo of one phase activity into other(s) may occur, this represents the basic flow. However, it is just that smearing which occurs between requirements and design that we wish to explore here. Identifying or defining problems and solving problems are viewed by many to be separate, distinguishable activities. They are complementary in that one identifies what must be done (requirements) while the other depicts how it will be done (design). But software designers complain bitterly that requirements are poorly defined while customers and analysts often complain that the design is not responsive to the problem(s) as they perceive it. Somehow software designers end up discovering previously unknown requirements and end up solving a problem which is foreign to the customer. Is there a workable mechanism to reduce this difficulty?
Special interest groups
Venue: Proceedings of the conference on APL (1969)

On Saturday, July 12, at 11:30 a.m., the &ldquo;birds-of-a-feather&rldquo; groups met in individual rooms. As far as we have been able to determine, there were at least seven groups which convened. Some of the sessions merely evolved into demonstrations of programs in the terminal rooms. Rumor has it that the informal groups in the Social Room (Student Center) accomplished as much. The terminals were available for use throughout most of the two days. There were special sign-on numbers assigned for the use (by terminal) of the registrants.
Algorithms for translating Ada multitasking
Authors: D. R. Stevenson
Venue: Proceedings of the ACM-SIGPLAN symposium on The ADA programming language (1980)

Algorithms are presented for translating the multitasking constructs of Ada into the language Ada-M. The purpose of the translation is to study various implementations of Ada tasking and their relative problems, merits, and efficiencies. The multiprocessing constructs of Ada-M are lower level than those of Ada and, hence, flexible enough to permit development of a variety of compilation techniques for Ada tasking. Ada-M is sufficiently high-level, however, to permit the implementations to be developed quickly and understandably. Requirements for data structures, scheduling, and other pertinant elements of Ada tasking compilation are identified by the translation.
A &ldquo;core + modules&rdquo; approach to Fortran standardization
Authors: Walt Brainerd
Venue: Proceedings of the 1979 annual conference (1979)

In January 1978, ANSI X3J3 voted to adopt a framework consisting of a &ldquo;core&rdquo; and &ldquo;modules&rdquo; for developing the next revision of the ANSI Fortran standard. Of course, this is a decision that could be reversed if the approach appears to be unsuitable or technically unsound after some experimentation. However, the approval of this procedure is an indication that the committee wants to invest considerable effort in an attempt to make this approach work. There are at least three reasons for adopting the &ldquo;core + modules&rdquo; approach: (1) to provide a mechanism to interface with collateral standards and implementations in major applications areas, (2) to provide a mechanism for having optional functional areas described within the standard, (3) to specify a smaller, more elegant language than Fortran 77 without decreasing the status of Fortran 77 as a standard language.
Architecture of virtual machines
Authors: R. P. Goldberg
Venue: Proceedings of the workshop on virtual computer systems (1973)

In this paper we develop a model which represents the addressing of resources by processes executing on a virtual machine. The model distinguishes two maps: the &oslash;-map which represents the map visible to the operating system software running on the virtual machine, and the f-map which is invisible to that software but which is manipulated by the virtual machine monitor running on the real machine. The &oslash;-map maps process names into resource names and the f-map maps virtual resource names into real resource names. Thus, a process running on a virtual machine addresses its resources under the composed map f o &oslash;. In recursive operation, f maps from one virtual machine level to another and we have f o f o ... o f o &oslash;. The model is used to describe and characterize previous virtual machine designs. We also introduce and illustrate a general approach for implementing virtual machines which follows directly from the model. This design, the Hardware Virtualizer, handles all process exceptions directly within the executing virtual machine without software intervention. All resource faults (VM-faults) generated by a virtual machine are directed to the appropriate virtual machine monitor without the knowledge of processes on the virtual machine (regardless of the level of recursion).
Hardware microcontrol schemes using PLAs
Authors: Christos A. Papachristou
Venue: Proceedings of the 14th annual workshop on Microprogramming (1981)

Four new schemes for microprogram control design with programmable logic arrays (PLAs) are proposed. The general structure of the first three schemes consists of three units namely, the microcode memory (ROM), the microsequencer PLA, and a register-counter. The basic idea is to store only branching information, by means of control constructs or transactions, in the PLA(s). These transactions have simple jump-type or continue-type formats with only the jump being embedded in PLA(s). A more general structure, scheme 4, is also proposed with the objective to generate powerful transactions implementing complex control constructs, such as microsubroutines, nested microprogram loops, etc., in addition to multiway branch capability. These transactions contain horizontally formatted directive bits and, hence, they exhibit a measure of parrallelism. The aim is to transform the sequencing structure of a microprogram into a &ldquo;program&rdquo; composed of these transactions. However, a directive-driven processor is required to execute each transaction in order to produce the desired address.
Alternatives for interconnection of public packet switching data networks
Authors: Vic DiCiccio, Carl A. Sunshine, James A. Field, Eric G. Manning
Venue: Proceedings of the sixth symposium on Data communications (1979)

CCITT has proposed Recommendation X.75 as a technique for interconnecting public data networks in a standard way. However, this is not the only or necessarily the best approach. This paper focuses on two major factors in determining the merits of different network interconnection approaches, and compares the X.75 approach to a few alternatives in each of these areas. One of the determining factors for interconnection is the willingness of each network to cooperate. X.75 requires a high degree of cooperation and uniformity of each network's operations. Another determining factor in interconnection is the degree of gateway participation in providing various levels of end-to-end service, such as virtual circuit and terminal handling services. The gateway may fully participate in and &ldquo;terminate&rdquo; the protocol for a given service, or may not participate in the protocol at all. The former leads to a stepwise implementation of an end-to-end service while the latter results in an endpoint approach. CCITT has chosen a largely terminating approach for virtual call service, but an endpoint approach for terminal handling. The degree of participation is examined for three alternatives: the X.75 gateway, the subscriber gateway and the datagram gateway.
Path systems and language recognition
Authors: Stephen A. Cook
Venue: Proceedings of the second annual ACM symposium on Theory of computing (1970)

Our main result, theorem 2, gives a bound on the storage required for a Turing machine to simulate certain time-bounded pushdown machines. The theorem is a generalization of the result appearing in [3] stating that any context-free language can be recognized by a deterministic Turing machine within storage (log n)2. We introduce a combinatorial object, called a path system, develop its theory briefly, and use the theory to prove both the result on pushdown machines and the result on context free languages, as well as a third result. The third result is the Theorem of Savitch [5] stating that a non-deterministic L(n) - storage bounded Turing machine can be simulated by a deterministic (L(n))2 - storage bounded Turing machine.
Superimposing direct search methods for parameter optimization onto dynamic simulation models
Authors: Rainer Heckler, Hans-Paul Schwefel
Venue: Proceedings of the 10th conference on Winter simulation - Volume 1 (1978)

An integrated modular software package has been developed by the Programme Group of Systems Analysis and Technological Development (STE) of the Nuclear Research Centre at J&uuml;lich (KFA) to provide automatic optimization of a set of user defined decision variables. This optimization module containing different procedures for direct search algorithms can be added to our FORTRAN based Data-Model-Interface (DMI) for dynamic simulation (1). The latter is formulated independently from an actual simulation model as well as from the actual parameters, the objective, and the constraints which are chosen. Once initiated it controls all user specified input values and the linkage between the optimization algorithm and the simulation model. Taking the KFA-energy model (2) as an example one application for finding a specific energy policy is demonstrated.
A model for hardware description and verification
Authors: George J. Milne
Venue: Proceedings of the 21st Design Automation Conference (1984)

Integrated circuit verification is required to establish the correctness of a circuit design before fabrication. This paper proposes CIRCAL as a model in which to describe the behaviour of devices in a natural, concise and accurate manner. CIRCAL supports a number of verification techniques which allow for the formal analysis of circuit behaviour. Properties of the model are outlined while simulation and proof techniques using CIRCAL are presented.
Instruction issue logic for pipelined supercomputers
Authors: Shlomo Weiss, James E. Smith
Venue: ACM SIGARCH Computer Architecture News (1984)

Basic principles and design tradeoffs for control of pipelined processors are first discussed. We concentrate on register-register architectures like the CRAY-1 where pipeline control logic is localized to one or two pipeline stages and is referred to as &ldquo;instruction issue logic&rdquo;. Design tradeoffs are explored by giving designs for a variety of instruction issue methods that represent a range of complexity and sophistication. These vary from the original CRAY-1 issue logic to a version of Tomasulo's algorithm, first used in the IBM 360/91 floating point unit. Also studied are Thornton's &ldquo;scoreboard&rdquo; algorithm used on the CDC 6600 and an algorithm we have devised. To provide a standard for comparison, all the issue methods are used to implement the CRAY-1 scalar architecture. Then, using a simulation model and the Lawrence Livermore Loops compiled with the CRAY FORTRAN compiler, performance results for the various issue methods are given and discussed.
Real-time simulation of multicounters by oblivious one-tape turing machines (Preliminary Draft)
Authors: Paul M.B. Vitányi
Venue: Proceedings of the fourteenth annual ACM symposium on Theory of computing (1982)

Each multicounter machine can be simulated in real-time by an oblivious one-head tape unit.
Simulation of resources in gantry machining center
Authors: Hulas H. King, Haluk Bekiroglu
Venue: Proceedings of the 11th conference on Winter simulation - Volume 1 (1979)

This paper addresses utilization of manpower and equipment resources in the three spindle, five axis gantry machine tool center at McDonnell Aircraft Company in St. Louis, Missouri. A GPSS (General Purpose System Simulation) model is developed to help analyze the impact of system changes so that cost effective decisions may be made about gantry fabrication operations. Besides resource utilization, the model provides a basis for making changes in the load mix on the machine tools and the number of set up men servicing this area. Emphasis of the paper is placed on model development and validation.
Introduction to computing VIA PSI
Authors: Thomas C. Richards
Venue: Proceedings of the thirteenth SIGCSE technical symposium on Computer science education (1982)

An introductory computer concepts course has been implemented using a Personalized System of Instruction. This experimental course is now in its fourth year of operation and is being taught on a regular basis. It makes use of textual materials, audio tapes and a detailed study guide as well as a novel telephone communication system.
The Brown University Student Operating System
Authors: David S. Wile, Robert G. Munck, Andries Van Dam
Venue: Proceedings of the 1967 22nd national conference (1967)

The tenet that students taking a computer science course (even, and especially, an introductory one) should get actual machine experience has gradually been accepted in the past few years. The Brown University Student Operating System (SOS) provides: 1) such a &ldquo;cut-down&rdquo; assembler; 2) an interpreter for simulating the simplified machine whose code the assembler produces; 3) a control program which optimizes program storage, provides line-by-line program editing, and gathers operating statistics; 4) a grading program for the four major problems in one of the introductory computer science courses using SOS. Our experience in the fall semester of 1966 indicates that we can provide assembly language teaching and processing to students of varying backgrounds at costs comparable to those mentioned for algebraic compilers.
Certification for the computer professional - individual preparation strategies
Authors: James S. Ketchel
Venue: Proceedings of the ACM '81 conference (1981)

This paper summarizes some historical and philosophical perspectives of professional certification and particularly the Professional Certificate in Data Processing (CDP). Methods whereby the computer practitioner may become prepared to sit for the CDP examinations are discussed.
The growth process of tropical trees: A simulation with graphic output
Authors: Carol Lewis Weeks, John Craig Comfort
Venue: Proceedings of the 15th conference on Winter Simulation - Volume 2 (1983)

Simulation is becoming an important tool of researchers studying the structure and adaptability of various botanical species. One goal of scientists is this field is the creation of models to explain global tree attributes, such as canopy shape, in terms of local growth behavior (the branching pattern). The validation and &ldquo;tuning&rdquo; of these models would be quite difficult without performing simulations based on the models constructed and then displaying the results of the simulation graphically. Models describing the structure and branching pattern of a species have incorporated both genetic factors and environmental influences on the species being analyzed. Simulation programs implementing models for three species of architecturally similar tropical canopy trees (Terminalia, Cameraria, and Tabernaemontana) have been created. These programs produce graphic output, as well as tabular information on the status of the tree at fixed time intervals. Examples are presented of a preliminary study of the effect of limiting branching density on tree structure.
Computing an invariant subring of k[X,Y]
Authors: Rosalind Neuman
Venue: Proceedings of the fourth ACM symposium on Symbolic and algebraic computation (1981)

We are interested in computing the invariant subring (also referred to as fixed ring) which is obtained as a result of the action of a certain finite group of k-linear automorphisms on the polynomial ring in two variables with coefficients in a field of characteristic p.
Microcomputers for non-professionals
Authors: Ivan Tomek, Wayne Brehaut
Venue: Proceedings of the twelfth SIGCSE technical symposium on Computer science education (1981)

Microcomputers are beginning to invade the lives of non-professionals. In the near future most people will be using them for entertainment and education both at home and in school. Undoubtedly many of them will soon discover that one of the main attractions of computers is the programming of them. This development is going to occur sooner if the programming environment is appropriate for non-professional users. In order for this to be a positive development from the point of view of professionals the environment must satisfy appropriately defined specifications. This presentation attempts to outline some of the basic desirable features of the non-professional user's environment. It then shows the implications of this specification for one of the essential components of these environments, the definition, translation, and run-time implementation of the preferred programming language. It is postulated that if the environment is defined to &ldquo;optimally&rdquo; reflect user's needs and professional's insights it will be accepted by the general public.
Integration of solid modeling and data base management for CAD/CAM
Authors: Y. C. Lee, K. S. Fu
Venue: Proceedings of the 20th Design Automation Conference (1983)

For the fast growing CAD/CAM technologies, geometric solid modeling plays one of the most important roles. In order to satisfy a variety of engineering applications, an integrated database management system based on solid modeling is highly desirable. In the proposed approach, a concise object representation scheme, Constructive Solid Geometry (CSG), is adopted as the basis for database design. The underlying generic relational model is found to be more adequate than the conventional relational model in characterizing the embedded data abstraction. A systematic method is devised for converting the CSG scheme into a generic model based on the BNF grammar which depicts the CSG scheme. A relational query language, SEQUEL, has been modified to define, control, and manipulate the flat relations which represent the highly structural generic model.
Clipping using homogeneous coordinates
Authors: James F. Blinn, Martin E. Newell
Venue: ACM SIGGRAPH Computer Graphics (1978)

Clipping is the process of determining how much of a given line segment lies within the boundaries of the display screen. Homogeneous coordinates are a convenient mathematical device for representing and transforming objects. The space represented by homogeneous coordinates is not, however, a simple Euclidean 3-space. It is, in fact, analagous to a topological shape called a &ldquo;projective plane&rdquo;. The clipping problem is usually solved without consideration for the differences between Euclidean space and the space represented by homogeneous coordinates. For some constructions, this leads to errors in picture generation which show up as lines marked invisible when they should be visible. This paper will examine these cases and present techniques for correctly clipping the line segments.
APL event / response programming
Authors: David A. Rabenhorst
Venue: Proceedings of the international conference on APL (1982)

A proposed mechanism is described by which responses can be programmed to react to APL events. Events can be trapped, and a response is executed either where the trap is laid, or where the event occurs.
Communication with secrecy constraints
Authors: Alon Orlitsky, Abbas El Gamal
Venue: Proceedings of the sixteenth annual ACM symposium on Theory of computing (1984)

Let x, y, z be finite sets, X,Y random variables uniformly distributed over x&times;y, f a function from x&times;y to Z and 0&le;&egr;&le1. A person PX knows X and a person PY knows Y and they want to exchange X and Y. An eavesdropper who knows their protocol listens to their communication in order to obtain information about f(X, Y). PX and PY want to ensure that for every value (x,y) of (X,Y) the eavesdropper's a priori and a posteriori probabilities of {f(X,Y)&equil;j} are &egr;-close for all j. Therefore, they encrypt some of the transmitted bits. The problem is to find a protocol that minimizes the number of bits encrypted in the worst case. Two kinds of protocols are considered: deterministic and randomized. For deterministic protocols it is shown that for all x,y, Boolean f (|Z|&equil;2) and &egr;>0, there exists a protocol that requires no more than 2&bull; log(1/&egr;) + 16 bits. An example where log(1/&egr;) &minus; 1 bits must be encrypted is given. For K valued functions (|Z|&equil;K) it is shown that at most CK(&egr;) bits must be encrypted (independent of x, y and f ). The results are extended to N persons communicating over a broadcast channel. The proofs rely on results concerning partitions of K valued matrices. For randomized Protocols it is shown that for all x,y Boolean f, and all possible joint distributions of X,Y (not only uniform), total secrecy (&egr;&equil;0) can be achieved using only two secret bits.
Stochastic simulation of the temporal and spatial interactions in urban travel
Authors: Ryuichi Kitamura, Tenny N. Lam, Masahiro Hioki
Venue: Proceedings of the 15th conference on Winter simulation - Volume 1 (1983)

The patterns of urban travel are influenced by the interactions between four fundamental elements. Two of the elements are related to the individual traveler: time budget and activity pattern. The other two elements are related to the urban system: land use and transportation. These elements interact with each other within a framework of space and time. Based on a time dependent markov renewal model of trip chaining, it is possible to simulate the many properties of the constrained activity paths in space and time. Through the stochastic processes in the model, the interrelationships between travel movements and urban structures can be simulated and examined.
The function-class
Authors: Toshiaki Kurokawa
Venue: Proceedings of the 1980 ACM conference on LISP and functional programming (1980)

The 'function-class' concept is introduced and explained in this paper. The 'function-class' specifies the function's input procedure, input requirement, output requirement and output procedure. It includes the argument evaluation process in its input procedure part, and the output value type in its output requirement part. But it has other components which can describe the function's behavior in more detail. The 'function-class' can be represented in a declarative form, i.e. in a calculus form using *, +, and &minus; operators. The function can also be defined in a declarative form. This format increases the readability of the program. The feasibility of the 'function class' is considered in the context of its implementation in LISP-like environments. The 'function-class' idea is not restricted to LISP language, although it has been originally developed in the LISP-1.9 context. There are several utilizations including program checking and optimized compilation.