物件導向軟體之架構(Object-Oriented Software Construction)探討

Product design is a highly involved, often ill-defined, complex and iterative process, and the needs and specifications of the required artifact get more refined only as the design process moves toward its goal. An effective computer support tool that helps the designer make better-informed decisions requires efficient knowledge representation schemes. In today's world, there is a virtual explosion in the amount of raw data available to the designer, and knowledge representation is critical in order to sift through this data and make sense of it. In addition, the need to stay competitive has shrunk product development time through the use of simultaneous and collaborative design processes, which depend on effective transfer of knowledge between teams. Finally, the awareness that decisions made early in the design process have a higher impact in terms of energy, cost, and sustainability, has resulted in the need to project knowledge typically required in the later stages of design to the earlier stages. Research in design rationale systems, product families, systems engineering, and ontology engineering has sought to capture knowledge from earlier product design decisions, from the breakdown of product functions and associated physical features, and from customer requirements and feedback reports. VR (Virtual reality) systems and multidisciplinary modeling have enabled the simulation of scenarios in the manufacture, assembly, and use of the product. This has helped capture vital knowledge from these stages of the product life and use it in design validation and testing. While there have been considerable and significant developments in knowledge capture and representation in product design, it is useful to sometimes review our position in the area, study the evolution of research in product design, and from past and current trends, try and foresee future developments. The goal of this paper is thus to review both our understanding of the field and the support tools that exist for the purpose, and identify the trends and possible directions research can evolve in the future.

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The evolution, challenges, and future of knowledge representation in product design systems

A new methodology for extracting manufacturing features from CAD system

Features capture the engineering significance of a part model and serve as an important support tool for integrated manufacturing. Feature-based design systems typically act as ‘interpreters’ between the CAD and the CAM activities. These systems can be classified broadly into human-assisted feature definition systems, automatic feature recognition systems and design by features systems. Researchers have come to realize that the best system architecture for a feature-based system would be a blend of the above-mentioned approaches. This paper reviews the major developments in the field of feature-based modelling with particular emphasis on automatic feature recognition systems. The approaches used for automatic feature recognition systems are systematically categorized and discussed. Automated feature recognition systems are broadly categorized into volume feature recognition systems and surface feature recognition systems, and the published research in each of these categories is critically discus...

Feature-based modelling approaches for integrated manufacturing: state-of-the-art survey and future research directions

One of the fundamental problems in history-based parametric solid modelling systems is to identify topological entities (faces, edges, vertices) of solid models in such a way that the same entities can still be identified after the models have been reevaluated from the sequential history of modelling steps The Topological ID System, presented in this paper, systematically assigns IDs (names, labels) to topological entities in solid models When the history of modelling steps is edited and then automatically re-evaluated to produce a new version of the solid model, the IDs of topological entities in the old version of the solid model are mapped to IDs of the corresponding topological entities in the new version of the solid model This mapping defines the correspondence between topological entities in both models

A mechanism for persistently naming topological entities in history-based parametric solid models

A representation scheme is presented that is suitable for defining and operating form features. Five basic constituents, B-rep solid components, measure entities, size, location and constraints, are used to represent a single form feature. With these constituents, form features are defined structurally and procedurally. Parts are then represented by a higher-level structure, called a feature-dependency graph, in which feature-position operators link the form features. In the FDG model, dimensions are used to determine the size and locations of form features. This property makes the manipulation of form features more consistent with the designer's intent. A C ++ implementation of the physical data structure according to the logical representation scheme is discussed.

Representation scheme for defining and operating form features

A context-based object-oriented application framework for discrete event simulation

A methodology for designing animated simulation (AS) system has been presented. A Model-AnimatorScheduler paradigm was proposed for unifying different approaches of AS systems into a single structure and serving as a foundation for implementation and further research. A framework which identifies the specification and organization of AS systems was also proposed on the basis of such a methodology. An experimental AS system, SIMGRM?H, has finally been presented here under such a framework.

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Liang-Chyau Sheu

Papers

Representation scheme for defining and operating form features

A context-based object-oriented application framework for discrete event simulation

A framework for designing an animated simulation system based on model-animator-scheduler paradigm