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...
Three different approaches to type checking have been taken in object-oriented programming languages. Smalltalk-80 uses run-time type checking. C++ uses subtypes. A third alternative is to use parameterized types. We examine the difficulties of programming in an object-oriented fashion with compile-time type checking and argue that parameterized types are better...
Recent advances in diagnostic expert systems have been limited by the crucial Knowledge Acquisition Problem: to bring expert heuristics into logical, conditional rule forms useful for computer aided diagnosis. Some automatic systems with potential biomedical relevance that do acquire knowledge are reviewed here, and analyzed from the standpoint of possible...
Exploratory Data Analysis (EDA) is a lesser known field which has outgrown the bounds of statistics. It differs from ordinary, or “confirmatory”, data analysis. Originated by John Tukey, EDA aspires toward an open-ended meta-goal: to discover “all interesting” [nontrivial, normal form, valid] hypotheses about a domain that is represented by...
There is disagreement about the role and importance of typographic style (source code formatting and commenting) in program comprehension. Results from experiments and opinions in programming style books are mixed.
This paper presents principles of typographic style consistent and compatible with the results of program comprehension studies. It introduces the...
This paper presents the results of a controlled experiment comparing debugging abilities of novice, intermediate and skilled student programmers. Debugging performance differences were studied using two single-page Pascal programs: a binary search program and a median calculation program. Two types of semantic errors, array bounds and undefined variable, and two...
A database to be used by electrical circuit design, test, and repair expert systems must support both structural data and inferential data about the circuit. It is well known that engineering databases must support dynamic schema (re)definition of the structural data and entity-based access to it. We analyze this requirement...