Building large, heterogeneous, distributed software systems poses serious problems for the software engineer;achieving interoperability of software systems is still a major challenge. We describe an experiment in desi...
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The notion of "time" plays an important role when coordinating large, heterogeneous, distributed software systems. We present a generic coordination architecture that supports relative and absolute, discrete...
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Although precedences are often used to resolve ambiguities in programming language descriptions, there has been no parser-independent definition of languages which are generated by grammars with precedence rules. This...
Although precedences are often used to resolve ambiguities in programming language descriptions, there has been no parser-independent definition of languages which are generated by grammars with precedence rules. This paper gives such a definition for a subclass of context-free grammars. The definition is shown to be equivalent to the implicit definition an operator precedence parser gives. A problem with a language containing infix, prefix and postfix operators of different precedences is that the well-known algorithm, which transforms a grammar with infix operator precedences to an ordinary unambiguous context-free grammar, does not work. This paper gives an algorithm that works also for prefix and postfix operators, and the correctness of it is proved. An application of the algorithm is also presented.
We address the problem of performing a pipelined broadcast on a mesh architecture. Meshes require a different approach than other topologies, and their very nature puts a tighter bound on the performance that one can ...
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We address the problem of performing a pipelined broadcast on a mesh architecture. Meshes require a different approach than other topologies, and their very nature puts a tighter bound on the performance that one can hope to achieve. By using the appropriate techniques, however, one can obtain excellent performance for sufficiently long messages. The resulting algorithm will work on meshes of any dimension with any number of nodes. Our model assumes that the mesh is a torus and/or that it has bidirectional links and uses wormhole routing. Performance data from the Cray T3D are included.
The axiom system ACP of [BEK84a] was extended to cliscrete time in [BAB95]. Here we proceed to define the silent step in this theory in branching bisimulation semantics [GLW91, BAW90] rather than weak bisimulation sem...
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In this article a multimedia computer-assisted learning (MCAL) system is presented. The major objective of this work was to investigate the potential of using such systems as tools for transferring instructional cours...
In this article a multimedia computer-assisted learning (MCAL) system is presented. The major objective of this work was to investigate the potential of using such systems as tools for transferring instructional course information through various types of computer media as opposed to the classic CAL systems. The philosophy and techniques employed to design the system are investigated. Usage of the implemented system and its merits have been illustrated through its application to teach engineering students and technicians the theory and concepts of marine radar. System design, implementation, test, and revision phases are presented and discussed.
作者：
FAIRHEAD, DLHALL, CCSince graduating from Cleveland State University in 1965 with a Bachelor of Science degree in Mathematics
he has worked for the Navy at Annapolis participating in several different automation efforts ranging from design aids to surface ship bridge control. Mr. Fairhead has completed graduate work in Computer Science at the University of Maryland has a certificate in Computer Programming holds a patent and is a member of the Association for Computing Machinery (ACM). Upon graduation from Morgan State in 1962
Mr. Hall was employed as a physicist at the Naval Surface Warfare Center Carderock Division Annapolis until 1994. During that time period he served as program technical manager for propulsion technology and as senior project scientist for several automation projects including the Automated Ships Bridge project. Mr. Hall also served as a member of the initial Technical Director's Technology Application Team and of the Autonomic Ship Innovation Center Team. Mr. Hall is a member of the American Institute of Physics and Sigma Pi Sigma (National Physics Honor Society).
A growing concern about the shrinking size of the U.S. Navy budget and the pool from which selections will be made to ''man'' U. S. Navy shipboard systems has led to investigations on achieving improve...
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A growing concern about the shrinking size of the U.S. Navy budget and the pool from which selections will be made to ''man'' U. S. Navy shipboard systems has led to investigations on achieving improvements in affordability and operational effectiveness. One such investigation has resulted in the development of the Standard Monitoring and Control System (SMCS), a modular, open architecture control system which includes the control system components for propulsion, electric plant, auxiliaries, and damage control. The first major technology upgrade to SMCS will entail the insertion of Artificial Intelligence (AI) technologies into HM&E monitoring and control applications. The Intelligent Machinery Control Integration Task (IMCI) was established to provide a structural approach for this major technology upgrade. As part of the first phase of IMCI, an identification of intelligent control requirements, an assessment of AI technologies, and a survey of intelligent control applications were performed. This paper lists those HM&E-related shipboard operational requirements from which intelligent machinery control requirements will be identified. Also, there is an initial assessment of AI-related reasoning and the following AI technologies, knowledge-based systems, fuzzy logic, neural nets, and genetic algorithms. The survey provided some insight into applying AI technologies to SMCS shipboard operational requirements.
This paper describes an experimental message-driven programming system for fine-grain multicomputers. The initial target architecture is the J-machine designed at MIT. This machine combines a unique collection of arch...
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This paper describes an experimental message-driven programming system for fine-grain multicomputers. The initial target architecture is the J-machine designed at MIT. This machine combines a unique collection of architectural features that include fine-grain processes, on-chip associative memory;and hardware support for process synchronization. The programming system uses these mechanisms via a simple message-driven process model that blurs the distinction between processes and messages: messages correspond to processes that are executed elsewhere in the network. This model allows code and data to be distributed across the computers in the machine, and is supported at every stage of the program development cycle. The prototype system we have developed includes a basic set of programming tools to support the model;these include a compiler, linker, archiver, loader and microkernel. Although the concepts are language independent, our prototype system is based on GNU-C.
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