Computing Applications
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A computer science perspective of bridge design
What kinds of lessons does a classical engineering discipline like bridge design have for an emerging engineering discipline like computer systems design? Case-study editors Alfred Spector and David Gifford consider the insight and experience of bridge designer Gerard Fox to find out how strong the parallels are.
Embedded menus: selecting items in context
In many situations, embedded menus represent an attractive alternative to the more traditional explicit menus, particularly in touchtext, spelling checkers, language-based program editors, and graphics-based systems.
Computers, complexity, and the Statue of Liberty restoration
Twentieth-century techniques such as computer-aided engineering and finite-element analysis were used to restore the nineteenth-century monument.
A locally adaptive data compression scheme
A data compression scheme that exploits locality of reference, such as occurs when words are used frequently over short intervals and then fall into long periods of disuse, is described. The scheme is based on a simple heuristic for self-organizing sequential search and on variable-length encodings of integers. We prove that it never performs much worse than Huffman coding and can perform substantially better; experiments on real files show that its performance is usually quite close to that of Huffman coding. Our scheme has many implementation advantages: it is simple, allows fast encoding and decoding, and requires only one pass over the data to be compressed (static Huffman coding takes two passes).
The structure of microcomputer file systems
With an understanding of the structure of microcomputer file systems and what causes incompatibilities between them, it is possible to write software that will enable one system to read files written by another—provided they have physically compatible hardware.
Andrew: a distributed personal computing environment
The Information Technology Center (ITC), a collaborative effort between IBM and Carnegie-Mellon University, is in the process of creating Andrew, a prototype computing and communication system for universities. This article traces the origins of Andrew, discusses its goals and strategies, and gives an overview of the current status of its implementation and usage.
How not to lie with statistics: the correct way to summarize benchmark results
Using the arithmetic mean to summarize normalized benchmark results leads to mistaken conclusions that can be avoided by using the preferred method: the geometric mean.
An empirical study of the impact of user involvement on system usage and information satisfaction
"User involvement" in information system development is generally considered an important mechanism for improving system quality and ensuring successful system implementation. The common assumption that user involvement leads to system usage and/or information satisfaction is examined in a survey of 200 production managers. Alternative models exploring the causal ordering of the three variables are developed and tested via path analysis. The results demonstrate that user involvement in the development of information systems will enhance both system usage and the user's satisfaction with the system. Further, the study provides evidence that the user's satisfaction with the system will lead to greater system usage.
The relationship between benchmark tests and microcomputer price
A highly accurate model predicts microcomputer price based on benchmark performance by analyzing the impact on predicted price of fluctuations in system configuration and benchmark results.
A model curriculum for a liberal arts degree in computer science
This report proposes developing a rigorous undergraduate curriculum for a B.A.-degree program in computer science. The curriculum is intended as a model not only for high-quality undergraduate colleges and universities, but also for larger universities with strong computer science programs in a liberal arts setting.
A comment on “a fast parallel algorithm for thinning digital patterns”
A fast parallel thinning algorithm for digital patterns is presented. This algorithm is an improved version of the algorithms introduced by Zhang and Suen [5] and Stefanelli and Rosenfeld [3]. An experiment using an Apple II and an Epson printer was conducted. The results show that the improved algorithm overcomes some of the disadvantages found in [5] by preserving necessary and essential structures for certain patterns which should not be deleted and maintains very fast speed, from about 1.5 to 2.3 times faster than the four-step and two-step methods described in [3] although the resulting skeletons look basically the same.
Program style analysis: a natural by-product of program compilation
Analyzing program style may be properly considered an integral part of program compilation—as successfully implemented in two style-analysis tools for Fortran 77: AUTOMARK and ASSESS. The authors look forward to the day when all major language compilers routinely provide a standard style-analysis vector for users to interpret as they see fit.
A note on the Berry-Meekings style metric
A modification of the Berry-Meekings "style metric"—applied to software from the corporate environment—finds little relationship between this style metric and error proneness.
Shape the Future of Computing
ACM encourages its members to take a direct hand in shaping the future of the association. There are more ways than ever to get involved.
Get InvolvedCommunications of the ACM (CACM) is now a fully Open Access publication.
By opening CACM to the world, we hope to increase engagement among the broader computer science community and encourage non-members to discover the rich resources ACM has to offer.
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