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Communications of the ACM

Table of Contents


Proposed library of programs for personnel and related work


Letters to the editor: A tactical assault on systems procurement


Letters to the editor: on Congressman Brooks letter Re standardization


Letters to the editor: A base for language definition


Letters to the editor: On computer appreciation in the undergraduate curriculum


Information Retrieval: PEEKABIT, computer offspring of punched card PEEKABOO, for natural language searching

The “peekaboo” idea from punched card information retrieval methods has been mated with the idea of superimposed punching to produce a programming technique which cuts computer run time in half on a test search of 33,000 subject …

Experimental evaluation of information retrieval through a teletypewriter

Experiments designed to evaluate the capabilities of mechanized information retrieval systems, with emphasis on interactive (man-machine) language and on some of the mechanical and psychological limitations in their design, were …

Operating Systems: A statistical model for console behavior in multiuser computers

The ability of a computer system to communicate with the outside world efficiently is as important as its ability to perform computations efficiently. It is quite difficult to characterize a particular user, but rather easy to …

Computational Linguistics: Graphical input/output of nonstandard characters

A system developed at Harvard for graphically inputting and outputting nonstandard characters on a computer is printed. In principle, the system can deal with any orthography, although at present it is limited to 4000 Chinese …

Scientific Applications: An algorithm for identifying the ergodic subchains and transient states of a stochastic matrix

An algorithm for identifying the ergodic subchains and transient states of a stochastic matrix is presented. Applications in Markov renewal programming and in the construction of variable length codes are reviewed, and an updating …

PLEXUS—an on-line system for modeling neural networks

A description is presented of PLEXUS, a system which enables a user to construct and specify a neural network, to analyze the output data produced by the network, and to store and retrieve networks and data from a library. The …

Programming Techniques: An algorithm for the probability of the union of a large number of events

An algorithm is presented which efficiently evaluates the probability for the union of n independent and not mutually exclusive events. The problem is that of evaluating the sums of the products of all possible combinations of …

Algorithms: Algorithm 336: netflow


Algorithms: Remark on algorithm 248: netflow


Algorithms: Algorithm 337: calculation of a polynomial and its derivative values by Horner scheme


Algorithms: Remark on Algorithm 248: Netflow


Programming Languages: GPL, a truly general purpose language

A truly general purpose programming language, GPL, is described which contains facilities for constructing (within the language) new data types as well as facilities for operations performed upon them. The basic language is minimal …

Numerical Analysis: Numerical solution of a thin plate heat transfer problem

The numerical solution of a system of linear equations resulting from a discrete approximation to a thin plate heat transfer problem is considered. The slow convergence of point iterative methods is analyzed and shown to be caused …

A comparison of the correlational behavior of random number generators for the IBM 360

Hutchinson states that the “new” (prime modulo) multiplicative congruential pseudorandom generator, attributed to D.H. Lehmer, has passed the usual statistical tests for random number generators. It is here empirically shownautocorrelation …