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Communications of the ACM

Table of Contents

ACM Vice-President Carlson Asks: what are your standards?

A formal system for information retrieval from files

A generalized file structure is provided by which the concepts of keyword, index, record, file, directory, file structure, directory decoding, and record retrieval are defined and from which some of the frequently used file structures …

The multistore parser for hierarchical syntactic structures

A syntactic parser is described for hierarchical concatenation patterns that are presented to the analyzer in the form of linear strings. Particular emphasis is given to the system of “significant addresses” by means of which …

Translation equations

Input limited transduction expressions, or translation equations, are used to describe the syntax and left-context sensitive semantics for context-free languages. A formal procedure is given for deriving from a set of translation …

Spelling correction in systems programs

Several specialized techniques are shown for efficiently incorporating spelling correction algorithms into compilers and operating systems. These include the use of syntax and semantics information, the organization of restricted …

An efficient context-free parsing algorithm

A parsing algorithm which seems to be the most efficient general context-free algorithm known is described. It is similar to both Knuth's LR(k) algorithm and the familiar top-down algorithm. It has a time bound proportional to …

The use of quadratic residue research

Some of the problems of simulating discrete event systems, particularly computer systems, on a conventional digital computer are dealt with. The systems are assumed to be described as a network of interconnected sequential processes …

A variation on sorting by address calculation

The principles of address calculation and merging are combined to yield an efficient sorting technique. Detailed flowcharts of the most important program steps are included. The characteristics of the proposed sort are discussed …

The quadratic quotient method: a hash code eliminating secondary clustering

Secondary clustering as a cause of hash code inefficiency is discussed, and a new hashing method based on its eliminiation is presented. Comparisons with previous methods are made both analytically and empirically.

Computer education in a graduate school of management

Several years of experience have led to the belief that the creative design and evaluation of management information systems requires a thorough understanding of the related computer technology. Concepts such as paging and priority …

An interactive computer system using graphical flowchart input

An interactive computer system operational on a graphical computer terminal is described. This system was designed to demonstrate a method of programming by computer interpretation of a flowchart. The user draws a description …

Algorithm 374: Restricted partition generator [A1]

Algorithm 373: Number of doubly restricted partitions [A1]

Algorithm 375: Fitting data to one exponential [E2]

Algorithm 376: Least squares fit by f(x) = A cos(Bx+C [E2]

Certification of algorithm 127 [F5]: Ortho

Certification of algorithm 343 [F1]: eigenvalues and eigenvectors of a real general matrix

Remark on Algorithm: Algorithm 321 [S14] t-test probabilities and Algorithm 344: students t-distribution