Communications of the ACM

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 ...

A brief study is made of the propagation of errors in linear first-order difference equations. The recursive computation of successive derivatives of e^x/x and (cos x)/x is considered as an llustration.

A scheduling algorithm is proposed which is intended to minimize changes of tasks on processors and thereby reduce overhead. The algorithm also has application to more general resource allocation problems. It is implemented by means of a method for ...

Recent experiments in programming natural language question-answering systems are reviewed to summarize the methods that have been developed for syntactic, semantic, and logical analysis of English strings. It is concluded that at least minimally ...

An operational extensible language system is described. The system and its base language are appraised with respect to efficiency, flexibility, and utility for different categories of users.

A method for extracting a smooth polygonal contour from a digitized image is illustrated. The ordered sequence of contour points and the connection graph of the image are first obtained by a modified Ledley algorithm in one image scan. A minimal ...

This proposed American National Standard has been accepted for publication by American National Standards (formerly USASI) Committee X3, Computers and Information Processing. In order that the final version of the proposed standard reflect the largest ...

Intermediate computations in an “Extremely Portable Random Number Generator” by J. B. Kruskal [Comm. ACM 12, 2 (Feb. 1969), 93-94] exceed 15 bits plus sign. This is a severe limitation since the majority of small computers uses a 16 bit (15 bits plus ...