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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 mode 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. [ABSTRACT FROM AUTHOR]

The article presents information on the proposed American Standard, "Eleven-Sixteenths Inch Perforated Paper Tape." This standard covers the physical dimensions of the paper tape and its perforations. This standard is for perforated paper tape with fully punched round holes. The punched tape shall have an overall width of 0.686 inch plus or minus 0.003 inch after the tape has been conditioned to within 69.5 degrees F to 76.5 degrees F and 48 percent to 52 percent relative humidity for a period of 24 hours. The tape shall be used for recording up to five levels of information across the tape. The feed holes in the tape shall be fully punched and round with a diameter of 0.046 inch plus 0.002 minus 0.001 inch. All holes punched in the tape shall nominally center on the true intersection of longitudinal and perpendicular transverse center lines spaced 0.100 inch apart. Tolerances on locations of code holes in any one transverse row, relative to the center lines of the feed hole in that row, shall be plus or minus 0.002 inch in the transverse direction and plus or minus 0.003 inch in the longitudinal direction.

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 troublesome. First, ... 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present a comparison of some computer simulation languages and of some of the packages by which each is implemented. Some considerations 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, GPSS 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. [ABSTRACT FROM AUTHOR]

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 for monitor control is investigated for the case of task execution in a memory heirarchy of varying speeds. [ABSTRACT FROM AUTHOR]

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 "benche-marked" by test problems with known solutions. The reason for this fail- ure 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper is concerned with certain aspects of contention for main memory resources in a multiproagrammed 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 multi- programmed load are obtained. It is pointed out heuristically and demonstrated numerically that an increase is obtainable in the average execution interval of the multiprogrammed load over that resulting from equal fixed partitioning of main memory. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The article comments on the origin and history of publications in computing. Prior to the second World War, there was only disordered and infrequent publication about computing. The journals related to mathematics, science and engineering, carried occasional contributions concerning computations with mechanical aids. There was a scarce amount of publication concerning methods for efficient computing and the editors of the mathematical journals seemed to consider that papers concerning the process of actually dealing with complex numbers had insufficient content to justify publication by them. The publication started to increase in the early 1950s. A new journal was published in 1949, with the title "Digital Computer Newsletter of the Office of Naval Research," which provided a medium for the interchange among interested persons of information concerning recent developments in various digital computing projects. The first publications of the Association for Computing Machinery were the 1952 Proceedings of the Association meetings in Pittsburgh and Toronto.

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. [ABSTRACT FROM AUTHOR]

The article presents information on various meetings to be held in the field of computing in 1971. The Southeastern Region of the Association for Computing Machinery (ACM) is holding its Tenth Annual Conference in Mobile, Alabama on June 19, 2005 at the Admiral Semmes Hotel. The conference is being chaired by Ted E. Turner. The Washington Chapter of the ACM will hold its Tenth Annual Technical Symposium on June 24, 2005 at the National Bureau of Standards. The one-day symposium will consist of panel discussions and papers reviewing ten years of growth and change in the computing industry and looking into the future. The sixth annual ACM Urban Symposium will be held on October 29, 1971, at the New York Hilton Hotel. Sponsored by the New York Metropolitan Chapters of ACM, this Symposium brings together interested professionals from the computing field and from the urban problem areas, and provides a forum for the exchange of ideas, experiences, and information. The Technical Committee on Computer Architecture and the Midwest Area Committee of the IEEE Computer Society are co-Sponsoring a Workshop on Modular Computer Systems.

Discusses some of the thinking and philosophy behind changes in the communications of the journal of "Association for Computing Machines." Logistical and administrative reasons for the intended changes; Purposes and goals of the periodical; Technical papers relevant to the computer industry that are sought by the periodical.

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, areas for future work in this field are discussed. [ABSTRACT FROM AUTHOR]

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 programs 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 ape plication when circumstances are other than ideal. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 o 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In the main text of the paper [Comm. ACM 9, 12 (Dec. 1966), 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. Christoffel symbols calculated for 12 bask orthogonal coordinate systems are listed. [ABSTRACT FROM AUTHOR]

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 program is described, which has been developed in LISP far 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 lightpen. By use of a small unordered set of rewriting rules applied as a result of lightpen 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. [ABSTRACT FROM AUTHOR]

The article informs about some activities of the Association for Computing Machinery (ACM). The ACM's Washington D.C. Chapter's 1973 Technical Symposium will take place at the National Bureau of Standards, Oaithersburg, Maryland, on June 21. Program Chairman is Helmut E. Thiess. The article also informs that the 4th Annual Symposium of the ACM Special Interest Group on Computer Systems Installation Management is scheduled for October 18-19 in Las Cruces, New Mexico. Papers are invited on the following topics: security; virtual systems evaluation; data entry systems-COM; personnel evaluation, measurement, and development; nonprofessional status of data processing personnel; job estimation; etc. The American Society of Indexers will hold its Second Annual All-Day Meeting on Saturday, April 28, at the Graduate Center of the City University of New York. Editors, indexers, librarians and index users will participate in forums and speeches concerned with "Index Traps and Pitfalls: Human Generated/Computer Generated." Three speakers for the morning session include Jessica L. Harris, a professor.

The article reports on certain upcoming conferences, exhibitions, symposiums, and other events related to computing machinery. The Association for Computing Machinery (ACM) Southwest Region will sponsor a meeting on the "Philosophical, Moral, and Ethical Problems of the Computer Scientist in the Computerized Society." In addition to contributed papers by ACM members in the Southwest Region, the program will include special presentations. Donn B. Parker, ACM secretary, will speak on the New ACM Code of Professional Ethics. The Computing Center of the State University of New York at Stony Brook, New York, and the Long Island Chapter of the Association for Computing Machinery are jointly sponsoring the Third Annual Stony Brook Conference on "Advances in Computing" to be held at Stony Brook on June 9, 1967. The International Business Machines Corp. is providing financial assistance for the conference. "Spectrum of Data Processing" is the title of a one-day technical symposium to be held on May 26, 1967, that will be sponsored by the San Diego, California, chapter of the Association for Computing Machinery.

Presents letters to the editor commenting on issues related to computing machinery. Discussion on the research paper "Systematic Generation of Hamiltonian Circuits," by S.M. Roberts and Benito Flores; Highlights of several serious errors in the paper; Description of a straight-forward algorithm for the systematic generation of all Hamiltonian circuits of an undirected graph; Objections to the flowchart and programs presented in the paper; Comments of the research paper authors on criticism against their paper.

The article focuses on the objectives of the Association for Computing Machinery (ACM) for 1970. The ACM's literature is its most basic service to its members. Not every ACM member attends chapter meetings regularly; only a fraction of the members attend national conferences. But every member regularly receives the ACM publications. It is suggested that a fair fraction of the issues for the next two years be assigned to the largest and most active Special Interest Groups (SIG). Each designated SIG would be responsible for selecting and obtaining subject matter for one such special issue. The process of organizing the technical program for national conferences needs overhauling. The "call for papers" philosophy too often results in mish-mash sessions. Panel sessions can be simply excuses for delivering full papers--which escape refereeing and do not appear in the proceedings. The Professional Development program has had a very successful first year. It has brought high quality technical seminars to many cities throughout the country. It needs continued support, so as to offer more subjects in more cities. How can the ACM better serve the business data processing community, which represents over one-half of the computer field, for this the ACM needs a much more vigorous program addressed to supporting the technical competence of these people.

This article presents several forthcoming events related to the computing machinery. The University of Illinois 5th Annual Review of Electronics will be held from November 20-22 at Urbana. The conference is for researchers, development engineers and technical managers in government and industry, and will include laboratory visits and individual discussions with university faculty. Short technical papers will be given on solid state and quantum electronics, cybernetics and computers, and electromagnetics and plasma research. A conference on "Optimization" will be held at the University of Keele in Staffordshire from March 25-28, 1968. Survey papers will be presented on "unconstrained optimization," "constrained optimization by hill-climbing methods" and "non-linear programming by linear programming methods," and offers of original papers that are relevant to any of these three fields are invited. The program for the 8th Annual Symposium on Switching and Automata Theory to be held in Austin, Texas from October 18-20 has been completed.

Discusses a proposed reorganization of the Computer Systems Department of the Association for Computing Machinery. Information that the department has been divided into two sub-departments: Computer Architecture and Measurement, and Performance Evaluation; Functions and roles of the departments; Information on the steps taken by the association for the publication of valuable papers related to the field of computer science in the periodical "Communications of the ACM."

The article comments on issues related to membership of the Association for Computing Machinery (ACM). It is said ACM often get the feeling that the members of ACM don't really know each other well. It is suggested to enhance members' participation in activities to build a collective computing environment. It is noted that members can review papers and participate in panel discussion of ACM.

The article presents a calendar of events about the computer industry. The "1967 Spring Joint Committee Conference," which will be held on April 18-20, 1967 in Atlantic City, New Jersey invites papers to be presented during the conference. The American Documentation Institute will hold a convention on October 3-7, 1967 in Santa Monica, California. The International Federation of Information Processing Societies will hold its "1968 Congress" on August 5-10, 1968 in Edinburgh, Scotland.

This article presents information related to the 5th Annual Symposium of the San Francisco Bay Area Chapter of ACM. On October 29, 1965, the topic "Computers--Software for Online Systems," was discussed. Over 300 people attended this symposium which reflects the great interest in the topic. The papers given represented the broad interests in the time-sharing field of the diverse organizations from government, business and universities. The impact of online systems has been felt in each of these areas. The Octopus operating system for the Control Data 6600 is one of the first steps at Lawrence Radiation Laboratory, Livermore, California, to interconnect various types of computers and storage devices. This system provides a response within reasonable time to users located at remote teletypes. Up to 100 programs are known to the system at one time, of which ten are active and in main core. Programming the Octopus system has required two calendar-years and fifteen man-years.

The article reports on certain developments in the field of computing machinery. Late last year U.S. President Lyndon B. Johnson set up a National Commission on Technology, Automation and Economic Progress to study the impact of technological changes on American life. Howard R. Bowen, an economist and president of the University of Iowa, was nominated as chairman of the 14-member panel. David N. Freeman, a member of Association for Computing Machinery, was awarded the prize for the most significant paper presented at the 1904 Fall Joint Computer Conference. Installation of a large analog computer system has recently been completed by GPS Instrument Company at General Electric Co.'s Radio Guidance Operation in Syracuse, New York. ITT Research Institute is in process of organizing a computer cooperative for Chicago area structural engineers in Illinois. Computer technology is being utilized by the structural engineer because of the increasing complexity of the structural systems resulting from his search for optimum design.

The article offers news briefs related to the Association for Computing Machinery (ACM). ACM national chairman George Heller has certified the New Milford High School Computer Club as the first Secondary School Computer Club in Connecticut assisted by the association. Christophe Dupont and A. Kuevangueven were announced as winners of a student paper competition hosted by the French National Institute for Research in Computing and Automation.

The article reports on certain developments pertaining to the Association for Computing Machinery (ACM). The Special Interest Committee on Programming Languages of the ACM will issue an information bulletin on the string manipulation language SNOBOL. This bulletin will be distributed as an occasional supplement to SICPLAN Notices, the Committee's informal newsletter. The bulletin will also be used as a forum for the discussion of problems associated with the use and implementation of the language. At a recent meeting of the ACM Committee for Professional Activities of the Blind, it was decided that Science for the Blind, a small nonprofit organization, should act as a central depository for all literature in the computing field that is recorded for the blind. ACM will hold its 20th anniversary meeting- at the Sheraton Park Hotel in Washington, D.C. on August 29-31, 1967. Papers to be presented will stress historical perspective, present significant new developments, or explore trends and potential developments.