The design and implementation of a database computer architecture performance evaluation system (DACPES) are presented. DACPES is a simulation tool which can be configured to evaluate a class of parallel database comp...
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The design and implementation of a database computer architecture performance evaluation system (DACPES) are presented. DACPES is a simulation tool which can be configured to evaluate a class of parallel database computers (DBCs), which have shared-nothing architectures, use data flow query processing strategies, and support object-oriented databases. DACPES can be used to simulate concurrent multiple query processing in a parallel DBC under varying conditions. The functions and design issues for each of the modules of DACPES are discussed and a case study of the evaluation of an object flow computer using DACPES is presented.< >
This paper gives an overview of the Columbus software development environment (CSDE). CSDE is built for use in software development within the Columbus manned space program sponsored by the European Space Agency (ESA)...
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This paper gives an overview of the Columbus software development environment (CSDE). CSDE is built for use in software development within the Columbus manned space program sponsored by the European Space Agency (ESA). CSDE is offered to the Columbus consortium as the main cornerstone in the software process. It supports a classic waterfall model as defined by ESA standard PSS-05. The main emphasis is placed on utilization of commercial-off-the-shelf (COTS) tools integrated in an objected oriented environment facilitating a 'plug-in/plug-out' paradigm. The paper addresses details of the kind of large scale projects that will be supported, the design and integration platform chosen, implementation of the integration strategy, as well as the importance of an objectoriented approach. Furthermore, the importance of procurement, deployment, and support strategy is discussed.< >
作者：
M. BenarochMIS Group
School of Management Syracuse University Syracuse NY USA
Modeling expert knowledge using 'situation-action' rules is not always feasible in knowledge intensive involving volatile knowledge. In such domains, the size and the dynamic nature of the search space make it...
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Modeling expert knowledge using 'situation-action' rules is not always feasible in knowledge intensive involving volatile knowledge. In such domains, the size and the dynamic nature of the search space make it extremely difficult to setup a rule base and keep it accurate. An alternative approach suggests that in some domain many of the rules that experts use can be derived by reasoning from 'first-principles'. That approach entails modeling experts' deep knowledge, and emulating the reasoning processes with deep knowledge that allow experts to derive many rules and their justification. The author discusses the design and implementation of an object-oriented representation for the deep knowledge traders utilize in a business domain called hedging, which is knowledge intensive and involves volatile knowledge. He illustrates how deep knowledge modeled using that representation is used to support reasoning from first-principles. The author also analyzes features of that representation that were found to be beneficial in the development of a knowledge-based system called INTELLIGENT-HEDGER.< >
A formal object-oriented approach to the data structuring and data management of semiconductor wafer structure and device information is presented. The profile interchange format (PIF) is extended beyond a file format...
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A formal object-oriented approach to the data structuring and data management of semiconductor wafer structure and device information is presented. The profile interchange format (PIF) is extended beyond a file format "intersite" version in order to enhance the storage and access of profile information, the communication of profile information between cooperating tools, and the integration and portability of technology CAD tools. An intertool PIF toolkit is a programmatic interface to profile information, consisting of a library of objects for the storage and manipulation of data by technology CAD (TCAD) tools. PIF/Gestalt is presented as a test implementation of the toolkit which provides C and Common Lisp language interfaces, implemented on a data base for use in a CAD/CIM system for semiconductor process design and fabrication. Test applications using PIF/Gestalt demonstrate the desirability of the formal object model, the appropriateness of an object-oriented interface, and implementation of that model on an object-oriented data base.
Traditional database design methodologies are not appropriate for the specific requirements of object-oriented database systems and new database application areas. Apart from semantic complications arising from object...
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Traditional database design methodologies are not appropriate for the specific requirements of object-oriented database systems and new database application areas. Apart from semantic complications arising from object-oriented database structures with complex objects, arbitrary data types as attribute domains, or generalization hierarchies, specification and semantics of dynamic database behaviour has to be of main interest for typical object-oriented applications, too. We propose the use of a temporal logic as a specification language for dynamic object behaviour and point out the formal semantics of such database dynamics specifications. A layered conceptual database design methodology is presented together with a discussion on design support techniques for behaviour specifications. Finally, implementation aspects are treated.
This paper describes a technique to implement an object-oriented functional data model that optimizes performance for a given set of applications (workload). The technique involves grouping functions that are often re...
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This paper describes a technique to implement an object-oriented functional data model that optimizes performance for a given set of applications (workload). The technique involves grouping functions that are often referenced together or that are often composed. These groups are referred to as access trees which may be considered as abstract storage structures. The focus of this paper is the design of a set of access trees (called the cover) for a given conceptual schema so that the cost of processing the workload is as low as possible and the space of the cover is within some user-specified limit. It is found that using this implementation scheme, a significant reduction in access time is obtainable at the cost of a tolerable space increment. The paper describes the conceptual data model, the structure and use of access trees, an implementation of access trees, costs associated with operations on the access trees, and a methodology to design the optimal set of access trees for a conceptual schema with respect to a given workload. An experimental analysis of the performance of the technique is presented.
This paper shows how the object-oriented (00) paradigm, and KADS's 4-layer knowledge paradigm can be used to develop a design method for Knowledge Based systems (KBS). We will use an example to illustrate how this...
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Graph grammars, especially when enriched with attributes, can be used as a powerful software engineering technique. The main idea behind this approach is: A problem domain is modelled by a graph, the representation gr...
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ISBN:
(纸本)9783540544784
Graph grammars, especially when enriched with attributes, can be used as a powerful software engineering technique. The main idea behind this approach is: A problem domain is modelled by a graph, the representation graph, whose nodes correspond to the objects of the domain and whose edges to the relations between the objects, respectively. Typical operations which normally change the structure of the representation graph, like introducing new objects at a certain state of the problem description, or modifying relations between objects, are expressed by graph productions. Quantitative informations are handled by the attributes attached to the nodes of the representation graph. So, the implementation aspects are reduced to a very general and flexible data structure, namely graphs.
This thesis describes the design and implementation of a structured knowledge representation scheme within an object-oriented environment. The knowledge representation scheme is based on the system entity structure (S...
This thesis describes the design and implementation of a structured knowledge representation scheme within an object-oriented environment. The knowledge representation scheme is based on the system entity structure (SES), a labeled tree-like graph which can be used to represent families of systems. The object-oriented environment is the Knowledge Representation for object-oriented Simulation (KROS). A brief introduction to these two systems is made and a design of an automated model structuring system based on them is discussed. A detailed example based on a visual flight simulation graphical display system (GDS) is developed to demonstrate features of the model structuring system and show its utility. The SES has been implemented within KROS and does contribute formal ideas for decomposing systems. Implementing the SES within KROS allowed the use of the object-oriented methodology that KROS provides for algorithm implementation. The standardization provided by the Common LISP language allows the resulting system to be used on a variety of machines.
objectorientedsystems are too new for a universal methodology for implementation to have evolved. Only a few implementations have been discussed in any detail in the literature. The authors discuss one of the most d...
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objectorientedsystems are too new for a universal methodology for implementation to have evolved. Only a few implementations have been discussed in any detail in the literature. The authors discuss one of the most difficult parts of the implementation: the persistent storage of methods represented by explicit code stored with the data. They do this for an engineering environment, where methods may include processes which compute the relevant laws of physics and chemistry, carry out substantial numeric processing and process images as well as the more common processes which search through large knowledge bases, execute logical rules and analyse text objects.< >
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