Home → Magazine Archive → April 1977 (Vol. 20, No. 4)
Table of Contents
Letter from the Chairman of ACM's publications board: ACM's publications—whither, how and help
Stu Lynn
Pages 207-208
Subgoal induction
A proof method, subgoal induction, is presented as an alternative or supplement to the commonly used inductive assertion method. Its major virtue is that it can often be used to prove a loop's correctness directly from its input …
James H. Morris, Ben Wegbreit
Pages 209-222
The editing of picture segmentations using local analysis of graphs
A major problem in picture processing is the elimination of the large number of spurious regions that result from an initial segmentation by region growing techniques. Such regions have been eliminated either on the basis of
…
Steven L. Tanimoto, Theodosios Pavlidis
Pages 223-229
Studies in machine cognition using the game of poker
A progress report is presented of on-going research efforts concerning human decision making under uncertainty and risk and human problem solving and learning processes on the one hand, and machine learning, large scale programming …
Nicholas V. Findler
Pages 230-245
Analysis of design alternatives for virtual memory indexes
A class of index structures for use in a virtual memory environment is described. Design alternatives within this class of index structures are analyzed. These alternatives include a choice of search strategy, whether or not
…
K. Maruyama, S. E. Smith
Pages 245-254
The stage hypothesis and the s-curve: some contradictory evidence
This paper presents the results of a study testing the s-shaped budget curve of Nolan's stage model of computer development in an organization. Research on the data processing budgets of California counties fails to support the …
Henry C. Lucas, Jimmy A. Sutton
Pages 254-259
Approximating block accesses in database organizations
When data records are grouped into blocks in secondary storage, it is frequently necessary to estimate the number of blocks XD accessed for a given query. In a recent paper [1], Cardenas gave the expression XD = m(1 - (1 - 1/ …
S. B. Yao
Pages 260-261
Remark on uniform insertion in structured data structures
In a recent paper, Shneiderman and Scheuermann [1] have defined an interesting operation, called uniform insertion, whereby a (linked) data structure G2 can be embedded within another structure G1 in such a way that each data …
Clifford R. Hollander
Pages 261-262
Comment on weighted increment linear search for scatter tables
I would like to comment on an article by Fabrizio Luccio [1] which discusses weighted increment linear search for scatter tables.
S. K. Bandyopadhyay
Pages 262-263
Sorting on a mesh-connected parallel computer
Two algorithms are presented for sorting n2 elements on an n × n mesh-connected processor array that require O (n) routing and comparison steps. The best previous algoritmhm takes time O(n log n). The algorithms of this paper …
C. D. Thompson, H. T. Kung
Pages 263-271
Proof techniques for hierarchically structured programs
A method for describing and structuring programs that simplifies proofs of their correctness is presented. The method formally represents a program in terms of levels of abstraction, each level of which can be described by a
…
Lawrence Robinson, Karl N. Levitt
Pages 271-283
ACM forum
Robert L. Ashenhurst
Pages 286-287