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A previous paper presented an efficient algorithm, called the Recomputation Algorithm, for evaluating a rational expression to within any desired tolerance on a computer which performs variable-precision arithmetic operations. The Recomputation Algorithm can be applied to expressions involving any variable-precision operations having O(10-... + Σ ∣ε∣) error bounds, where p denotes the operation's precision and ε, denotes the error in the operation's with argument. This paper presents an efficient variable-precision exponential operation with an error bound of the above order. Other operations, such as log, sin, and cos, which have simple series expansions, can be handled similarly. [ABSTRACT FROM AUTHOR]

The article presents information on various chapters of the Association for Computing Machinery (ACM) across the U.S. The Greater Rio Grande Chapter of ACM has recently extracted from its files a list of the titles of all technical papers presented at Chapter meetings since its inception in 1957. Using a program developed by D.K. Robbins of Sandia Corp., a KWIC-type listing of permuted titles of these papers has been made. This listing has been distributed to all members of the Chapter. Topics and speakers at ACM Chapters across the U.S. indicate the current trends of interest in computer science and data processing. The ACM Tidewater Chapter is sponsoring this spring a professional development course on "Real-Time Computing." The course is given by the Chapter's professional development chairman, Cecil Frost, who is applications staff specialist for Control Data Corp. At its April 21, 1966 meeting, the Westchester-Fairfield Chapter heard William Orchard-Hays speak on "Linear Programming of Computational Techniques."

This paper discusses the multiplication of conformable sequences of row vectors, column vectors, and square matrices. The minimum time required to evaluate such products on ordinary serial computers as well as parallel computers is discussed. Algorithms are presented which properly parse suck matrix sequences subject to the constraints of the machine organization. [ABSTRACT FROM AUTHOR]

Various kinds of interference between communicating parallel processes have been examined by Dijkstra, Knuth and others. Solutions have been given for the mutual exclusion problem and associated subproblems, in the form of parallel programs, and informal proofs of correctness have been given for these solutions. In this paper a system of parallel processes is regarded as a machine which proceeds from one state S (i.e. a collection of pertinent data values and process configurations) to a next state 5' in accordance with a transition rule S ⇒ S . A set of such rules yields sequences of states, which dictate the system's behavior. The mutual exclusion problem and the associated subproblems are formulated as questions of inclusion between sets of states, or of the existence of certain sequences. A mechanical proof procedure is shown, which will either verify (prove the correctness of) or discredit (prove the incorrectness of) an attempted solution, with respect to any of the interference properties. It is shown how to calculate transition rules from the "partial rules" by which the individual processes operate. The formation of partial rules and the calculation of transition rules are both applicable to hardware processes as well as to software processes, and symmetry between processes is not required. [ABSTRACT FROM AUTHOR]

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]

In this paper an attempt is made to explore the logical foundations of computer programming by use of techniques which were first applied in the study of geometry and have later been extended to other branches of mathematics. This involves the elucidation of sets of axioms and rules of inference which con be used in proofs of the properties of computer programs. Examples are given of such axioms and rules, and a formal proof of a simple theorem is displayed. Finally, it is argued that important advantages, both theoretical and practical, may follow from a pursuance of these topics. [ABSTRACT FROM AUTHOR]

In this general paper the role of programming in advanced graduate training is discussed. Subject matter related to programming as well as programming per se is considered. The importance and application of formalism are considered and also the need for good empirical experimentation. A brief outline for a sequence of courses is included, and subject headings that have been obtained from an extensive bibliography are given. A bibliography of programming references is included. [ABSTRACT FROM AUTHOR]

Computer programming deals with an enormous variety of activities and is carried on by people with a great variety of backgrounds. It seems clear that part but not all of this activity h evolving toward a distinct professional field, but that the scope of this emerging profession, and some of its economic, social, and educational characteristics are as yet by no means well defined. In this paper, these issues are examined and some opinions about them are expressed. [ABSTRACT FROM AUTHOR]

The article presents information on the second annual Computer Science Conference (CSC) that was held in Detroit, Michigan, from February 12 to February 14, 1974. All the components of the first CSC were present: the invited addresses, the short-paper sessions of 12-15 minute presentations, the employment register, the book exhibit, the banquet, the department chairmen's luncheon, and the overlap with the annual SIGCSE Technical Symposium. New features were a terminal exhibit of commercial products and an academic and research display of materials and systems developed in various educational contexts by computer science departments and others. Over 400 abstracts were presented at the 49 short-paper sessions; approximately 250 available positions were listed by employers, about equally divided between academia and industry, and some 400 prospective employees were registered. Total conference attendance topped 1,200. All of which indicates a favorable prognosis for the future of the Conference. The banquet speaker was John Opel, senior vice-president of IBM.

Presents the author's comments on the paper "Reducing Truncation Errors by Programming," by J.M. Wolfe. Comments on Wolfe's proposal to use cascaded accumulators to evaluate a sum of the truncation errors; Remarks on the method used for rounding of errors; Advantages of using electronic computers which normalize floating-point sums before rounding or truncating them.