Software Engineering and Programming Languages
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Special-purpose processors in theoretical physics
Specially designed processors can provide a method for attacking some of the difficult computational problems facing theoretical physicists.
Symbolic mathematical computation
Standard programming languages are inadequate for the kind of symbolic mathematical computations that theoretical physicists need to perform. Higher mathematics systems like SMP address this problem.
Experimental mathematics: the role of computation in nonlinear science
Computers have expanded the range of nonlinear phenomena that can be explored mathematically. An “experimental mathematics facility,” containing both special-purpose dedicated machines and general-purpose mainframes, may someday provide the ideal context for complex nonlinear problems.
A generalized implicit enumeration algorithm for graph coloring
A generalized algorithm for graph coloring by implicit enumeration is formulated. A number of backtracking sequential methods are discussed in terms of the generalized algorithm. Some are revealed to be partially correct and inexact. A few corrections to the invalid algorithms, which cause these algorithms to guarantee optimal solutions, are proposed. Finally, some computational results and remarks on the practical relevance of improved implicit enumeration algorithms are given.
Amortized analyses of self-organizing sequential search heuristics
The performance of sequential search can be enhanced by the use of heuristics that move elements closer to the front of the list as they are found. Previous analyses have characterized the performance of such heuristics probabilistically. In this article, we use amortization to analyze the heuristics in a worst-case sense; the relative merit of the heuristics in this analysis is different in the probabilistic analyses. Experiments show that the behavior of the heuristics on real data is more closely described by the amortized analyses than by the probabilistic analyses.
Designing for usability: key principles and what designers think
This article is both theoretical and empirical. Theoretically, it describes three principles of system design which we believe must be followed to produce a useful and easy to use computer system. These principles are: early and continual focus on users; empirical measurement of usage; and iterative design whereby the system (simulated, prototype, and real) is modified, tested, modified again, tested again, and the cycle is repeated again and again. This approach is contrasted to other principled design approaches, for example, get it right the first time, reliance on design guidelines. Empirically, the article presents data which show that our design principles are not always intuitive to designers; identifies the arguments which designers often offer for not using these principles—and answers them; and provides an example in which our principles have been used successfully.
Pricing computer services: queueing effects
This article studies the effects of queueing delays, and users' related costs, on the management and control of computing resources. It offers a methodology for setting price, utilization, and capacity, taking into account the value of users' time, and it examines the implications of alternative control structures, determined by the financial responsibility assigned to the data processing manager.
An evaluation of retrieval effectiveness for a full-text document-retrieval system
An evaluation of a large, operational full-text document-retrieval system (containing roughly 350,000 pages of text) shows the system to be retrieving less than 20 percent of the documents relevant to a particular search. The findings are discussed in terms of the theory and practice of full-text document retrieval.
Predicting performance in an introductory computer science course
A group of 269 first-semester freshmen was used to predict both performance in an introductory computer science course and first-semester college grade point average by using information regarding the students' programs and performance in high school along with American College Testing Program (ACT) test scores.
A system for interactive viewing of structured documents
An existing typesetting system is tied by bridging software to an existing page-presentation program to effect both hard (typeset) copy and interactive browsing. The typesetting system formats documents for a variety of output devices, and the “browsing” feature appears to the user as simply another output device that happens to be interactive.
Excerpts from: An Information Systems Manifesto
James Martin talks with Leonard Kleinrock about the state of the art in data processing—how corporate and MIS managers should manage the new technology, and how computer science education should relate to it.
Programmer perceptions of productivity and programming tools
Psychometric scaling methods are applied to programmer productivity assessments of 20 tools to recommend a set of minimal, as well as more comprehensive, tools.
A specification language to assist in analysis of discrete event simulation models
Effective development environments for discrete event simulation models should reduce development costs and improve model performance. A model specification language used in a model development environment is defined. This approach is intended to reduce modeling costs by interposing an intermediate form between a conceptual model (the model as it exists in the mind of the modeler) and an executable representation of that model. As a model specification is constructed, the incomplete specification can be analyzed to detect some types of errors and to provide some types of model documentation. The primitives used in this specification language, called a condition specification (CS), are carefully defined. A specification for the classical patrolling repairman model is used to illustrate this language. Some possible diagnostics and some untestable model specification properties, based on such a representation, are summarized.
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