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Communications of the ACM

Table of Contents

On the optimization of performance of time-sharing systems by simulation

A simulation model of a time-sharing system with a finite noncontiguous store and an infinite auxiliary store is used to study the variation of system parameters such as store size, number of jobs allowed to execute simultaneously …

A proposal to establish a pseudo virtual memory via writable overlays

Many computer systems solve executable storage size problems for large programs by using overlays. However, it appears that no one overlay scheme contains a well-balanced combination of the most useful capabilities which are  …

Interference between communicating parallel processes

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 …

A Boolean matrix method for the computation of linear precedence functions

A modified version of Bell's Boolean matrix method for the computation of linear precedence functions associated with a conflict-free matrix of precedence relations is given. This algorithm not only detects when the precedence …

Computer-assigned codes from verbal responses

It is often desirable to convert verbal responses to multidigit codes. This conversion is generally accomplished by clerk-coders. A study was conducted to test the feasibility of translating verbal descriptions to numerical codes …

A starting method for solving nonlinear Volterra integral equations of the second kind

A fourth-order starting method is given for Volterra integral equations of the second kind and numerical examples are presented.

A sorting problem and its complexity

A technique for proving min-max norms of sorting algorithms is given. One new algorithm for finding the minimum and maximum elements of a set with fewest comparisons is proved optimal with this technique.

Certification of algorithm 363 [S15]

Remark on algorithm 343 [F2]

We had at our disposal a double precision version (all real variables are declared to be of type double precision) for the IBM 360/50 of the algorithm 343 [1] with logical IF statements converted to arithmetical ones. In the …

Remark on algorithm 370 [G5]

Remark on algorithm 393

Remark on algorithm 381 [G5]

Remark on algorithm 397 [H]

Remark on algorithm 418 [D1]

Individualizing instruction in a generative CAI tutor

ACM forum

Blocks—a new datatype for SNOBOL4

A new datatype, called a block, has been implemented for SNOBOL4. A block is a three-dimensional aggregate of characters in the form of a right parallelepiped, best thought of as a three-dimensional extension to a string. (The …

Computer science—a vicious circle

In many computer science departments throughout the country, including some interdisciplinary departments, the curriculum has placed increasing emphasis upon applied mathematics and the fundamental nature of computational systems …