Polychannel systems for mass digital communications
A new type of distributed computer system looks toward the time when computers will be used by everyone everywhere.
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Cube structures for multiprocessors
The exact structural relationship between the hypercube and multistage interconnection networks for multiprocessors is characterized here. By varying the node architecture, structures other than these two interconnection schemes can be derived.
Phoenix: a safe in-memory file system
Phoenix contains two timestamped versions of the in-memory file system allowing for a reserve version that ensures safety for diskless computers with battery-powered memeory.
An incremental constraint solver
An incremental constraint solver, the DeltaBlue algorithm maintains an evolving solution to the constraint hierarchy as constraints are added and removed. DeltaBlue minimizes the cost of finding a new solution after each change by exploiting its knowledge of the last solution.
Multicast tree construction in bus-based networks
Because of the multiple-access property of the media, the problem of constructing multicast trees in bus-based networks differs fundamentally from that in point-to-point networks. This article investigates the multicast tree construction for both general and specific network topologies.
DATAPLEX: an access to heterogeneous distributed databases
Diverse database management systems are used in large organizations. The heterogeneous distributed database system (DDS) can provide a flexible intergration of diverse databases for users and applications. This is because it allows for retrieval and update of distributed data under different data systems giving the illusion of accessing a single centralized database system.
Bounding delay on a multifarious token ring network
Interest in integrating voice and data on local computer networks has been building in recent years. Subsequently, much research has been devoted to various techniques that are implementable on existing networks using current standards. This exposition discusses the design issues in implementing a document retrieval system on a token ring network.
Design complexity measurement and testing
System designers can quantify the complexity of a software design by using a trio of finely tuned design metrics.
Entity-life modeling and structured analysis in real-time software design—a comparison
While structure analysis is sometimes used as a first step towards a real-time software design with concurrent tasks, a more appropriate task structure can often be based directly on concurrent patterns in the problem environment.
A technique for associating rewrite rules with productions so that many high-level transformations of a source file can be generated easily is described. While eclipsed in power by other editing and compiler generation systems supporting management of both synthesized and inherited attributes, this approach is especially simple to employ and is sufficient in power to deal with a wide class of problems arising from practical applications.
Lessons learned from modeling the dynamics of software development
Software systems development has been plagued by cost overruns, late deliveries, poor reliability, and user dissatisfaction. This article presents a paradigm for the study of software project management that is grounded in the feedback systems principles of system dynamics.
What best predicts computer proficiency?
Identifying variables that predict computer aptitude can help educators and employers target potential students and employees. The authors examine a number of possible explanatory variables including demographic profiles, high school achievements, prior computer training and experience, cognitive styles, and problem-solving abilities.
An experimental analysis of the performance of fourth generation tools on PCs
The performance of several Fourth Generation Language (4GL) tools is analyzed empirically and compared with equivalent programs written in the third generation COBOL programming language. A set of performance benchmarks consisting of thirteen separate functions is presented which encompasses the areas of simulating the operators of the relational algebra, accessing records in the database, and updating the database. This serves as a baseline for comparing the various 4GL systems.
HDTV and the computer industry
In the 1940s, television and radio combinations like the one on the left were the precursors of today's "entertainment centers ." About 25 years later, black and white television gave way to color. The next leap, high resolution television coupled with CD quality stereo may be coming soon. Last April, in the deep hours of the night, NBC, Channel 4 in New York City, announced a test: viewers would witness the first broadcast of the Sarnoff Research Center's Advanced Compatible Television system. The program of choice: the Saint Patrick's Day Parade. Researchers at the Sarnoff Center in Princeton, NJ, watched the signal, which emanated from WNBC at the World Trade Center in New York, on experimental high-definition monitors. The Sarnoff group, along with ABC and General Electric's consumer electronics division, has invested $60 million to develop a system that has twice the lines of regular TV screens (1050), scans at the same rate (29.97 frames per second), and enhances the current standard signal. A planned two-step approach to advanced television, the second phase would provide greater detail to those who bought wide-screen monitors, but it still would be compatible with today's TVs.
The Sarnoff system is one of 20 advanced television research projects under way in this country, including those of the Zenith Electronics Group in cooperation with AT&T Microelectronics, Massachusetts Institute of Technology's Advanced Television Research Program, the New York Institute of Technology, the Del-Ray Group, and North American Philips. Many have applied for matching funds from DARPA, which has earmarked $30 million for the next three years—half slated for transmission research and half for display technology. As of August 1989, five companies had been granted money for display technology. Newco Inc. of San Jose, CA, Raychem Corporation of Menlo Park, CA, Texas Instruments Inc. of Dallas, TX, and Projectavision Inc. of New York will receive money for projection display systems. Photonics Technology Inc. of Northwood, OH, was selected for flat panel display technology. More money may be forthcoming, as pressure is exerted to create systems to compete with or to supplant high-definition television (HDTV) as offered by Japan's national broadcasting organization Nippon Hoso Kyokai (NHK) and Europe's Eureka systems.
A single adaptable user interface (AUI) which allows the user to switch between any number of different dialogue modes at any time—even in the middle of a command—can be useful to a variety of users who are neither beginners nor experts. It can also be used in applications where different dialogue modes are appropriate for the various parameters of a single command. An implemented user interface management system (UIMS) suggests the practicality of AUIs and their automatic generation.
Information technologies for the 1990s: an organizational impact perspective
When a thing is new, people say: "It is not true." Later, when its truth becomes obvious, they say: "It is not important." Finally, when its importance cannot be denied, they say: "Anyway, it is not new."
Adapted from William James
User cube: a taxonomy of end users
The user cube, a precise and comprehensive graphical taxonomy designed to provide a common base for understanding and classifying end users in organizations, can be used to assess the risks associated with end-user computing.
The Computing Research Board's 1987-1988 Taulbee Survey includes the latest statistics on production and employment of Ph.D.'s and faculty in computer science and engineering. Included also are departments offering Ph.D.'s in computer engineering.
A finite and real-time processor for natural language
People process natural language in real time and with very limited short-term memories. This article describes a computational architecture for syntactic performance that also requires fixed finite resources.
Impact of a restricted natural language interface on ease of learning and productivity
People process natural language in real time and with very limited short-term memories. This article describes a computational architecture for syntactic performance that also requires fixed finite resources.
An evaluation tool for measuring authoring system performance
A model for producing objective and precise measurements of the power and performance of authoring systems is described. An animation task is given as an example of the model's potential as a tool for evaluating authoring systems along the dimensions of functionality, flexibility, and productivity.
The case against user interface consistency
Designers striving for user interface consistency can resemble Supreme Court justices trying to define pornography: each of us feels we know it when we see it, but people often disagree and a precise definition remains elusive. A close examination suggests that consistency is an unreliable guide and that designers would often do better to focus on users' work environments.
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