Sign In

Communications of the ACM

Table of Contents

ACM president's letter: ACM planning

Computational algorithms for closed queueing networks with exponential servers

Methods are presented for computing the equilibrium distribution of customers in closed queueing networks with exponential servers. Expressions for various marginal distributions are also derived. The computational algorithms …

Information theory applied to the conversion of decision tables to computer programs

Using ideas from information theory, this paper develops a heuristic algorithm that converts a limited entry decision table to a tree structured computer program with near minimum average processing time. The method is applicable …

Design of tree structures for efficient querying

A standard information retrieval operation is to determine which records in a data collection satisfy a given query expressed in terms of data values. The process of locating the desired responses can be represented by a tree …

Empirical working set behavior

The working set model for program behavior has been proposed in recent years as a basis for the design of scheduling and paging algorithms. Although the words “working set” are now commonly encountered in the literature dealing …

A simple technique for structured variable lookup

A simple technique for the symbol-table lookup of structured variables based on simple automata theory is presented. The technique offers a deterministic solution to a problem which is currently handled in a nondeterministic  …

Reversible execution

The ability to backtrack, or retrace, the execution of a computer program has gained wider acceptance recently as a desired feature within a programming language. This is particularly useful in two different applications: (1) …

Sard kernels for certain bivariate cubatures

An error analysis for some bivariate cubatures is given. The remainders are obtained by the use of Sard kernels. Numerical results and computer graphs are given for some of the kernel functions.

Algorithm 455: analysis of skew representations of the symmetric group

Algorithm 456: routing problem

Algorithm 457: finding all cliques of an undirected graph

Remark on algorithm 323 [G6]

Remark on algorithm 420 [J6]

Remark on algorithm 408

Remark on algorithm 429 [C2]

Evaluation and selection of file organization—a model and system

This work first discusses the factors that affect file (data base) organization performance, an elusive subject, and then presents a methodology, a model and a programmed system to estimate primarily total storage costs and average …