Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

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Author: search.filters.author.Mark, LeoSubject: search.filters.subject.databases

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    INformation Systems for Integrated Manufacturing (INSIM)
    (1992) Harhalakis, George; Lin, Chang-Pin; Mark, Leo; ISR
    A mechanism with the potential to control the information flow among all of the manufacturing application systems, in order to streamline factory activities, based on company-specific and company-wide policies and procedures is proposed here. The goal is to achieve a fully integrated manufacturing management system. The INformation Systems for Integrated Manufacturing (INSIM) reflects a design methodology to build a knowledge base to serve as the control mechanism.
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    Update Dependencies in the Relational Model
    (1991) Mark, Leo; Roussopoulos, N.; Cochrane, Roberta J.; ISR
    Relational database systems suffer from the lack of a rich update language. In this paper we present the Update Dependency Language which allows the database designer to specify a procedure for each update that is activated when attempts are made to perform the update. Each procedure integrates the update dependencies for an update and provides an operational semantics for the update which is maintained by the system. We provide a formal definition for this language, illustrate its use, and discuss concurrency control issues related to integrating such a language into a database system.
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    Relational Database Support for Complex Objects Defined by Grammars
    (1991) Cochrane, Roberta J.; Mark, Leo; ISR
    Context-free grammars provide the basis for many useful tools such as parsergenerators, compiler-compilers and syntax-directed editors. This paper demonstrates the potential benefits obtained when context-free grammars are used to define complex objects in the relational model. The grammar formalism facilitates relational queries on the hierarchical structure of these objects and promotes the use of grammar-based tools as front ends to relational database systems.
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    INformation Systems for Integrated Manufacturing (INSIM) - A Design Methodology
    (1991) Harhalakis, George; Lin, Chang-Pin; Mark, Leo; Muro, P.R.; ISR
    Full control and management of information flow in manufacturing has not yet been achieved, mainly because of the data inconsistencies and lack of established functional relationships among different manufacturing application systems. Research toward CIM has been concentrating on the computerization of individual functions, such as computer aided design and shop floor control, and the integration of data relations, such as global database frameworks and distributed database management systems. A mechanism to control the information flow among all of the manufacturing application systems, in order to streamline factory activities based on company-specific and company-wide policies and procedures is proposed here. The goal is to achieve a fully integrated manufacturing management system. The INformation Systems for Integrated Manufacturing (INSIM) reflects a design methodology to build a knowledge base to serve as the control mechanism. This design methodology features an enhanced graphic modeling tool - Updated Petri Nets (UPN) - which is capable of modeling database updates and retrievals, under specific constraints and conditions, and uses a hierarchical modeling approach. Finally, a prototype rule based system, using the INSIM methodology, is being implemented. It assimilates the functionality and assertains the control of information flow between Computer Aided Design, Process Planning, Manufacturing Resource Planning and Shop Floor Control.