| Project/Area Number |
07680438
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
情報システム学(含情報図書館学)
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| Research Institution | Toho University |
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Principal Investigator |
NISHIMURA Yoshiyuki Toho University, Department of Science, Professor, 理学部, 教授 (70023075)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | discrete event system / Petri net / condition / event net / partial language / activity / net construction / stepwise refinement |
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| Research Abstract |
In advance of the start of this research project, the author and his coworkers had defined the following condition/event net (C/E net) construction problem : given a partial language over a set of events as specification, construct a C/E net whose activity coincides with the specification. A variant of this is the problem to construct a C/E net which meets the specification using auxiliary events if necessary. The former and the latter problem will be called auxiliary-event-free and auxiliary-event-introduced problem, respectively. The author and his coworkers studied these problems and obtained several results including the fact that every solution of auxiliary-event-free problem consists of atoms 'compatible' with the specification.
Under these backgrounds the followings were obtained in this research project.
1. An algorithm for finding all atoms compatible with a given partial language was developed.
2. A method of finding the set of all solutions of auxiliary-event-free C/E net construction problem was proposed.
3. A Petri net construction problem was defined as a generalization of auxiliary-event-introduced C/E net construction problem and its solvability was discussed.
4. A new concept, hierarchical specification, was introduced for both auxiliary-event-free and auxiliary-event-introduced C/E net construction problems. It was shown that the concept permits stepwise refinement of construction processes.
5. A method to solve auxiliary-event-introduced construction problems with finite specification was presented. A method for the same type of problems with periodical specification was also obtained.
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