We believe concreteness, direct manipulation and responsiveness in a visual programming language increase its usefulness. However, these characteristics present a challenge in generalizing programs for reuse, especially when concrete examples are used as one way of achieving concreteness. In this paper, we present a technique to solve this problem by...
This report describes "VIGRAM" (Visual Programming) which is a program understanding and complexity metric analysis tool for Pascal programs. VIGRAM is implemented on the Macintosh as one part of the "O.S.U." (Qregon Speedcode Universe) project. With VIGRAM, the source code of a Pascal procedure can be displayed as a visual...
Performance of a reliable storage subsystem for a centralized database system was studied by simulation. The reliable storage subsystem studied consists of three redundant disk units that are updated one at a time from a consistent database state to another consistent database state, Thus, even if a central processor and/or...
This paper presents the initial results from an empirical study of mechanical design engineers. In this study, six engineers were video-taped solving real mechanical design problems. Preliminary analysis of this protocol data has yielded several important findings, including (a) mechanical designers progress from systematic to opportunistic behavior as the design...
Acoustic position estimation is used where high accuracy navigation is required over a small area, such as for searching or for collecting gravitational or geomagnetic data. In this position estimation method, a surface ship or submersible periodically sends out a high-frequency acoustic 'ping' at a prearranged frequency. This ping is...
System architectures for interconnecting large numbers of processors are being widely studied [AG82,TH75,TR82]. Of particular interest in such architectures is the exploitation of concurrency among processors. This concurrency can be parallelism, in which different parts of a single data case are processed at the same time, or pipelining, in which...
This grant supported acquisition of a minicomputer system for departmental research. The equipment selected is a DEC VAX-11/750 system, installed in remodeled space in the Computer Science (formerly Farm Crops) Building. Grant funds for equipment acquisition were supplemented by support from the Tektronix Foundation.
After completion of the physical facilities...
Advanced computer architectures are centered around the parallel computer systems. This project is focused on the experiment on two parallel computer architectures : Sequent Balance 21000 shared memory multiprocessor and Cogent XTM distributed system.
A set of benchmark programs are implemented using "C" language and Dynix parallel programming library on...