Special-purpose processors in theoretical physics
Specially designed processors can provide a method for attacking some of the difficult computational problems facing theoretical physicists.
Architecture and Hardware
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Monte Carlo methods in theoretical high-energy physics
Although lattice field theorists have been able to develop new approaches to the Monte Carlo method and to successfully apply them in Bosonic calculations, faster and larger computers are needed for Fermion-field evaluations.
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.
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.
Computer science in secondary schools: curriculum and teacher certification
Computer science in secondary schools is an area of increasing interest and concern to educators as well as to computer science professionals. Each of the next two reports addresses an issue of major importance regarding computer science in secondary schools. The first report recommends computer science courses for the secondary school curriculum, and the second report recommends requirements for teacher certification in computer science.In 1983 the ACM Education Board initiated efforts to formulate recommendations for secondary school computer science. Two task forces, one for curriculum recommendations and the other for teacher certification recommendations, were established under the Education Board's Elementary and Secondary Schools Subcommittee. The work of the two task forces was also supported by the IEEE Computer Society Educational Activities Board, and the final reports from the task forces were jointly approved by the ACM and IEEE-CS boards in July 1984. Thus the reports are significan't not only for the important issues that they address, but also because they represent a joint activity between ACM and the IEEE Computer Society.The work of the two task forces is summarized in the next two reports. The full reports are available as the publication Computer Science in Secondary Schools: Curriculum and Teacher Certification, Order Number 201850, from the ACM Order Department, P.O. Box 64145, Baltimore, MD 21264.
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.
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.
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.
Grosch’s law re-revisited: CPU power and the cost of computation
Does Grosch's law, which postulated that the costs of computer systems increase at a rate equivalent to the square root of their power, still hold? The age of mini-, micro-, and supercomputers seems to have complicated the situation. When computers are grouped according to their size and power, Grosch's law seems to hold within each group, but not between different groups.
The Manchester prototype dataflow computer
The Manchester project has developed a powerful dataflow processor based on dynamic tagging. This processor is large enough to tackle realistic applications and exhibits impressive speedup for programs with sufficient parallelism.
Reduced instruction set computers
Reduced instruction set computers aim for both simplicity in hardware and synergy between architectures and compilers. Optimizing compilers are used to compile programming languages down to instructions that are as unencumbered as microinstructions in a large virtual address space, and to make the instruction cycle time as fast as possible.
Sixty-four small computers are connected by a network of point-to-point communication channels in the plan of a binary 6-cube. This “Cosmic Cube” computer is a hardware simulation of a future VLSI implementation that will consist of single-chip nodes. The machine offers high degrees of concurrency in applications and suggests that future machines with thousands of nodes are both feasible and attractive.
Optimization criteria for checkpoint placement
Mean response time and availability as optimization criteria for checkpoint placement are better replaced by workable formulas that calculate the ratio between the marginal gain accrued to users who experience system failure and the (presumably slight) loss suffered on average by all users.
A software design method for real-time systems
DARTS—a design method for real-time systems—leads to a highly structured modular system with well-defined interfaces and reduced coupling between tasks.
The median filter is well-known [1, 2]. However, if a user wishes to predefine a set of feature types to remove or retain, the median filter does not necessarily satisfy the requirements. A more general filter, called the Weighted Median Filter, of which the median filter is a special case, is described. It enables filters to be designed with a wide variety of properties. Particular cases of filter requirements are discussed and the corresponding filters are derived. The notion of a minimal weighted median filter, of a subclass that act identically, is introduced and discussed. The question of finding the number of distinct ways a class of filters can act is considered and solved for some classes.
We are entering a new era in very high performance computing that will be dominated by parallel architectured systems. It is critical for the United States to maintain its leadership as this new era, with its broadened applications, evolves over the next decade. Toward this end the National Science Foundation sponsored a workshop in November 1983 to focus the collective strength of universities, industry, and government on projects for development of knowledge-intensive industries.
Where can you find a solid, forthright overview of the computer systems and management behind airline reservations? NASA's space shuttle? Or any of the multitude of other large computer systems that support important projects or national activities? It's hard, sometimes impossible: partly because the people who worked on such systems often do not have the time to write about their experiences: and partly because many professional journalists who interview these people do not have the technical background to ferret out answers to the fundamental design questions addressed in these systems.
Laser optical disk: the coming revolution in on-line storage
Commercially available only recently, the optical disk drive uses a laser beam to burn impressions onto a plastic disk. Employing a highly focused beam rather than a diffuse magnetic field to write, the laser optical disk drive yields storage densities up to 10 times those of magnetic disks.
A virtual memory system for picture processing
A virtual memory system designed specifically for picture processing, Raster Handler 2 provides programs with efficient access to pixels. It features square partition of images, imbalanced allocation of frames, and nondemand page replacement. RH2 is implemented in software and incorporates a prepaging algorithm designed specifically for picture processing.
Accommodating uncertainty in software design
Recognition that most software is domain dependent (DD) is extremely important because the most commonly used software life-cycle models are not adequate for DD software. The nature of DD software, and the need to manage its life cycle effectively, calls for a new approach to software design and the implementation of software development environments.
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