874,353 research outputs found

    Design and implementation of an integrated surface texture information system for design, manufacture and measurement

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    The optimised design and reliable measurement of surface texture are essential to guarantee the functional performance of a geometric product. Current support tools are however often limited in functionality, integrity and efficiency. In this paper, an integrated surface texture information system for design, manufacture and measurement, called “CatSurf”, has been designed and developed, which aims to facilitate rapid and flexible manufacturing requirements. A category theory based knowledge acquisition and knowledge representation mechanism has been devised to retrieve and organize knowledge from various Geometrical Product Specifications (GPS) documents in surface texture. Two modules (for profile and areal surface texture) each with five components are developed in the CatSurf. It also focuses on integrating the surface texture information into a Computer-aided Technology (CAx) framework. Two test cases demonstrate design process of specifications for the profile and areal surface texture in AutoCAD and SolidWorks environments respectively

    Advanced Tools and Technologies for Collaborative Product Development and Knowledge Management

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    The shortcomings of the current state-of-the-art in distributed / collaborative product development of engineering products from concept to production are: A lack of an integrated interface for the full spectrum of functions needed by complex conceptual design for manufacture and assembly; and management and re-use of concept design knowledge within an integrated design environment. Recommendations are given on the integration of these disparate technologies for the benefit of collaborative work teams to enable them to use a seamlessly integrated interface to develop, review, analyse and reuse engineering and manufacturing knowledge and models within the enterprise and the supply chain. A proposed methodology and a functional description of such a system is presented. The system utilises the ProtĂ©gĂ©-2000 expert system on top of the Windchill data management / collaboration software. International Standard for the Exchange of Product model data – STEP is to be used for machining feature definition

    Ontology based semantic-predictive model for reconfigurable automation systems

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    Due to increasing product variety and complexity, capability to support reconfiguration is a key competitiveness indicator for current automation system within large enterprises. Reconfigurable manufacturing systems could efficiently reuse existing knowledge in order to decrease the required skills and design time to launch new products. However, most of the software tools developed to support design of reconfigurable manufacturing system lack integration of product, process and resource knowledge, and the design data is not transferred from domain-specific engineering tools to a collaborative and intelligent platform to capture and reuse design knowledge. The focus of this research study is to enable integrated automation systems design to support a knowledge reuse approach to predict process and resource changes when product requirements change. The proposed methodology is based on a robust semantic-predictive model supported by ontology representations and predictive algorithms for the integration of Product, Process, Resource and Requirement (PPRR) data, so that future automation system changes can be identified at early design stages

    Hybridation of Bayesian networks and evolutionary algorithms for multi-objective optimization in an integrated product design and project management context

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    A better integration of preliminary product design and project management processes at early steps of system design is nowadays a key industrial issue. Therefore, the aim is to make firms evolve from classical sequential approach (first product design the project design and management) to new integrated approaches. In this paper, a model for integrated product/project optimization is first proposed which allows taking into account simultaneously decisions coming from the product and project managers. However, the resulting model has an important underlying complexity, and a multi-objective optimization technique is required to provide managers with appropriate scenarios in a reasonable amount of time. The proposed approach is based on an original evolutionary algorithm called evolutionary algorithm oriented by knowledge (EAOK). This algorithm is based on the interaction between an adapted evolutionary algorithm and a model of knowledge (MoK) used for giving relevant orientations during the search process. The evolutionary operators of the EA are modified in order to take into account these orientations. The MoK is based on the Bayesian Network formalism and is built both from expert knowledge and from individuals generated by the EA. A learning process permits to update probabilities of the BN from a set of selected individuals. At each cycle of the EA, probabilities contained into the MoK are used to give some bias to the new evolutionary operators. This method ensures both a faster and effective optimization, but it also provides the decision maker with a graphic and interactive model of knowledge linked to the studied project. An experimental platform has been developed to experiment the algorithm and a large campaign of tests permits to compare different strategies as well as the benefits of this novel approach in comparison with a classical EA

    A framework for a computer aided design system for product oriented manufacturing systems

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    In this paper we present a framework and an associated support system for the design of Product Oriented Manufacturing Systems (POMS). This includes the characterization and description of the structure and components of the support system, including database, user interface and knowledge base. The framework components are integrated into an organized system called CADS_POMS (Computer Aided Design System for POMS)

    A systematic approach for integrated product, materials, and design-process design

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    Designers are challenged to manage customer, technology, and socio-economic uncertainty causing dynamic, unquenchable demands on limited resources. In this context, increased concept flexibility, referring to a designer s ability to generate concepts, is crucial. Concept flexibility can be significantly increased through the integrated design of product and material concepts. Hence, the challenge is to leverage knowledge of material structure-property relations that significantly affect system concepts for function-based, systematic design of product and materials concepts in an integrated fashion. However, having selected an integrated product and material system concept, managing complexity in embodiment design-processes is important. Facing a complex network of decisions and evolving analysis models a designer needs the flexibility to systematically generate and evaluate embodiment design-process alternatives. In order to address these challenges and respond to the primary research question of how to increase a designer s concept and design-process flexibility to enhance product creation in the conceptual and early embodiment design phases, the primary hypothesis in this dissertation is embodied as a systematic approach for integrated product, materials and design-process design. The systematic approach consists of two components i) a function-based, systematic approach to the integrated design of product and material concepts from a systems perspective, and ii) a systematic strategy to design-process generation and selection based on a decision-centric perspective and a value-of-information-based Process Performance Indicator. The systematic approach is validated using the validation-square approach that consists of theoretical and empirical validation. Empirical validation of the framework is carried out using various examples including: i) design of a reactive material containment system, and ii) design of an optoelectronic communication system.Ph.D.Committee Chair: Allen, Janet K.; Committee Member: Aidun, Cyrus K.; Committee Member: Klein, Benjamin; Committee Member: McDowell, David L.; Committee Member: Mistree, Farrokh; Committee Member: Yoder, Douglas P

    Developing a Knowledge-based System for Complex Geometrical Product Specification (GPS) Data Manipulation.

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    Geometrical product specification and verification (GPS) matrix system is a universal tool for expressing geometrical requirements on product design drawings. It benefits product designers through providing detailed description of functional requirements for geometrical products, and through referring to corresponding manufacturing and verification processes. In order to overcome current implementation problems highlighted in this paper, a GPS knowledge base and a corresponding innovative inference mechanism have been researched, which led to the development of an integrated GPS knowledge-based system to facilitate rapid and flexible manufacturing requirements. This paper starts with a brief introduction of GPS, GPS application problems and the project background. It then moves on to demonstrate a unified knowledge acquisition and representation mechanism based on the category theory (CT) with five selected examples of this project. The paper concludes with a discussion on the future works for this projec

    Knowledge-based design support and inductive learning

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    Designing and learning are closely related activities in that design as an ill-structure problem involves identifying the problem of the design as well as finding its solutions. A knowledge-based design support system should support learning by capturing and reusing design knowledge. This thesis addresses two fundamental problems in computational support to design activities: the development of an intelligent design support system architecture and the integration of inductive learning techniques in this architecture.This research is motivated by the belief that (1) the early stage of the design process can be modelled as an incremental learning process in which the structure of a design problem or the product data model of an artefact is developed using inductive learning techniques, and (2) the capability of a knowledge-based design support system can be enhanced by accumulating and storing reusable design product and process information.In order to incorporate inductive learning techniques into a knowledge-based design model and an integrated knowledge-based design support system architecture, the computational techniques for developing a knowledge-based design support system architecture and the role of inductive learning in Al-based design are investigated. This investigation gives a background to the development of an incremental learning model for design suitable for a class of design tasks whose structures are not well known initially.This incremental learning model for design is used as a basis to develop a knowledge-based design support system architecture that can be used as a kernel for knowledge-based design applications. This architecture integrates a number of computational techniques to support the representation and reasoning of design knowledge. In particular, it integrates a blackboard control system with an assumption-based truth maintenance system in an object-oriented environment to support the exploration of multiple design solutions by supporting the exploration and management of design contexts.As an integral part of this knowledge-based design support architecture, a design concept learning system utilising a number of unsupervised inductive learning techniques is developed. This design concept learning system combines concept formation techniques with design heuristics as background knowledge to build a design concept tree from raw data or past design examples. The design concept tree is used as a conceptual structure for the exploration of new designs.The effectiveness of this knowledge-based design support architecture and the design concept learning system is demonstrated through a realistic design domain, the design of small-molecule drugs one of the key tasks of which is to identify a pharmacophore description (the structure of a design problem) from known molecule examples.In this thesis, knowledge-based design and inductive learning techniques are first reviewed. Based on this review, an incremental learning model and an integrated architecture for intelligent design support are presented. The implementation of this architecture and a design concept learning system is then described. The application of the architecture and the design concept learning system in the domain of small-molecule drug design is then discussed. The evaluation of the architecture and the design concept learning system within and beyond this particular domain, and future research directions are finally discussed

    Structuring and Provision of Manufacturing knowledge through the Manufacturing Resource Ontology

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    One challenge in manufacturing-integrated product development is the accessibility of the required manufacturing knowledge. Here, ontologies offer the possibility to structure and formalize information in the form of a knowledge base in order to act as a generic interface to the manufacturing and design specific systems. This paper describes the development of a generic knowledge base called MARON (MAnufacturing Restriction ONtology) for the structured representation of manufacturing restrictions via formalized manufacturing capabilities. Using the example of an expert system for process element-oriented manufacturability analysis, it is shown how MARON contributes to automated decision support in the context of manufacturing-oriented design

    D&T subject knowledge and its relationship with designing and making

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    The new paradigm for design and technology introduced by Breckon in 2001 re-opened the debate about the nature and assessment of design and technology (D&T) in schools. He proposed a model with four elements each independently assessed. Design and technology subject knowledge was one of these elements. This re-opened the debate about the relationship between designing and subject knowledge. This paper charts a brief history of the change in thinking about this relationship, particularly design process models. Research with focus groups of students in higher education, all with experience of doing D&T at GCSE level, throws further light on what is currently happening in schools and particularly the GCSE examination system. Comparisons are made with how subject knowledge is used to support designing within degree level product design courses. The paper concludes with a call for a re-think of how subject knowledge and designing can be taught in a more integrated way in schools, possibly using the product design model as a starting point
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