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This paper presents a summary of research into the development and implementation of a domain-independent, computer-based model for the conceptual design of complex mechanical systems [1]. The creation of such a design model includes the integration of four major concepts: (1) the use of a graphical display for visualizing the conceptual design attributes: (2) the proper representation of the complex data and diverse knowledge reguired to design the system; (3) the integration of quality design methods into the conceptual design: (4) the modeling of the conceptual design process as a mapping between functions and forms. Using the design of an automobile as a case study, a design environment was created which consisted of a distributed problem-solving paradigm and a parametric graphical display. The requirements of the design problem with respect to data representation and design processing were evaluated and a process model was specified. The resulting vehicle design system consists of a tight integration between a blackboard system and a parametric design system. The completed system allows a designer to view graphical representations of the candidate conceptual designs that the blackhoard system generates.  相似文献   

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Successful data warehouse (DW) design needs to be based upon a requirement analysis phase in order to adequately represent the information needs of DW users. Moreover, since the DW integrates the information provided by data sources, it is also crucial to take these sources into account throughout the development process to obtain a consistent reconciliation of data sources and information needs. In this paper, we start by summarizing our approach to specify user requirements for data warehouses and to obtain a conceptual multidimensional model capturing these requirements. Then, we make use of the multidimensional normal forms to define a set of Query/View/Transformation (QVT) relations to assure that the conceptual multidimensional model obtained from user requirements agrees with the available data sources that will populate the DW. Thus, we propose a hybrid approach to develop DWs, i.e., we firstly obtain the conceptual multidimensional model of the DW from user requirements and then we verify and enforce its correctness against data sources by using a set of QVT relations based on multidimensional normal forms. Finally, we provide some snapshots of the CASE tool we have used to implement our QVT relations.  相似文献   

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Successful data warehouse (DW) design needs to be based upon a requirement analysis phase in order to adequately represent the information needs of DW users. Moreover, since the DW integrates the information provided by data sources, it is also crucial to take these sources into account throughout the development process to obtain a consistent reconciliation of data sources and information needs. In this paper, we start by summarizing our approach to specify user requirements for data warehouses and to obtain a conceptual multidimensional model capturing these requirements. Then, we make use of the multidimensional normal forms to define a set of Query/View/Transformation (QVT) relations to assure that the conceptual multidimensional model obtained from user requirements agrees with the available data sources that will populate the DW. Thus, we propose a hybrid approach to develop DWs, i.e., we firstly obtain the conceptual multidimensional model of the DW from user requirements and then we verify and enforce its correctness against data sources by using a set of QVT relations based on multidimensional normal forms. Finally, we provide some snapshots of the CASE tool we have used to implement our QVT relations.  相似文献   

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本文论述了基于偏序关系的进化技术在计算机辅助概念设计中的应用,为了说明基于偏序关系的进化技术在开发面向用户的进化系统中的有效性,我们给出了一个计算机辅助概念设计系统,它可以辅助设计师更好地完成概念创新设计。作为应用,我们已经将本系统应用在建筑概念设计中,本文以办公楼建筑造型的概念设计为例来说明本系统。  相似文献   

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本文论述了基于偏序关系的进化技术在计算机辅助概念设计中的应用。为了说明基于偏序关系的进化技术在开发面向用户的进化系统中的有效性,我们给出了一个计算机辅助概念设计系统,它可以辅助设计师更好地完成概念创新设计。作为应用,我们已经将本系统应用在建筑概念设计中,本文以办公楼建筑造型的概念设计为例来说明本系统。  相似文献   

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A methodology to design data bases for finite element analysis and structural design optimization is described. The methodology considers three views of data organization-conceptual, internal, and external. Tabular and matrix forms of data are included. The relational data model is used in the data base design. Entity, relation, and attributes are considered to form a conceptual view of data. First, second, and third normal forms of data are suggested to design an internal model. Several aspects such as processing, iterative needs, multiple views of data, efficiency of storage and access time, and transitive data are considered in the methodology.  相似文献   

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The aim of the conceptual step in database design is to describe data involving in the application in a formal and abstract way, without any concern to the specific model and language chosen for the implementation. In statistical applications, data are described at different levels of aggregation, from elementary facts of the reality to complex aggregations such as classifications, time series, indexes. The paper describes a methodology for conceptual design of statistical databases that provides the designer suitable strategies for defining such different levels of aggregation starting from user requirements, and checking the completeness, coherence and minimality of the conceptual schema at the different levels. The methodology makes use of two data models for the representation of data: for elementary data the Entity-Relationship model, widely used in database applications, and for summary data a new model is proposed, designed to be an effective trade-off between expressive power and simplicity of use.  相似文献   

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Requirements analysts consider a conceptual model to be an important artifact created during the requirements analysis phase of a software development life cycle (SDLC). A conceptual, or domain model is a visual model of the requirements domain in focus. Owing to its visual nature, the model serves as a platform for the deliberation of requirements by stakeholders and enables requirements analysts to further refine the functional requirements. Conceptual models may evolve into class diagrams during the design and execution phases of the software project. Even a partially automated conceptual model can save significant time during the requirements phase, by quickening the process of graphical communication and visualization.This paper presents a system to create a conceptual model from functional specifications, written in natural language in an automated manner. Classes and relationships are automatically identified from the functional specifications. This identification is based on the analysis of the grammatical constructs of sentences, and on Object Oriented principles of design. Extended entity-relationship (EER) notations are incorporated into the class relationships. Optimizations are applied to the identified entities during a post-processing stage, and the final conceptual model is rendered.The use of typed dependencies, combined with rules to derive class relationships offers a granular approach to the extraction of the design elements in the model. The paper illustrates the model creation process using a standard case study, and concludes with an evaluation of the usefulness of this approach for the requirements analysis. The analysis is conducted against both standard published models and conceptual models created by humans, for various evaluation parameters.  相似文献   

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Concept generation plays a critical role in product design especially in the early design phase when functional requirements are either uncertain or partially known. To cope with the uncertainty imposed by the varying work environment, resilient design has often been called upon to leverage system capacity from the perspective of functional requirements. While the resilient design has been advanced recently, how to design a resilient product structure so to accommodate more functional requirements at the conceptual design phase remains challenging. To tackle this issue, we propose a methodology to support resilient conceptual design using functional decomposition and conflict resolution. To reduce the impact imposed by potential issues and uncertain environments, the overall system functional requirements are defined based on five principles of resilient design. The redundant conceptual scheme that meets functional requirements is given resilience through functional decomposition and conflict resolution. A case study of the conceptual design of a hard rock coring structure present to demonstrate the feasibility of the proposed approach. The results yielded have suggested that the proposed approach can not only support resilient conceptual design, but also leverage design reliability and robustness under uncertainty, especially in terms of varying work environments.  相似文献   

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进入新世纪以来,科技进步和市场经济的迅速发展,使人们对空间环境的认识和要求发生了根本的变化,特别是而对激烈的市场竞争工作节奏的加快,人们的办公时间不断延长,对现代办公空间环境的设计要求变得越来越高,工作环境的舒适与否也变得越来越重要。本文从办公室环境规划入手,分析其设计原则,以及人性化和光与色彩的应用,就办公空间设计的趋势和设计内容进行分析,对设计人员起到一定的指导性作用。  相似文献   

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Product-service system (PSS) approach has emerged as a competitive strategy to impel manufacturers to offer a set of product and services as a whole. A three-domain PSS conceptual design framework based on quality function deployment (QFD) is proposed in this research. QFD is a widely used design tool considering customer requirements (CRs). Since both product and services influence satisfaction of customer, they should be designed simultaneously. Identification of the critical parameters in these domains plays an important role. Engineering characteristics (ECs) in the functional domain include product-related ECs (P-ECs) and service-related ECs (S-ECs). ECs are identified by translating customer requirements (CRs) in the customer domain. Rating ECs’ importance has a great impact on achieving an optimal PSS planning. The rating problem should consider not only the requirements of customer, but also the requirements of manufacturer. From the requirements of customer, the analytic network process (ANP) approach is integrated in QFD to determine the initial importance weights of ECs considering the complex dependency relationships between and within CRs, P-ECs and S-ECs. In order to deal with the vagueness, uncertainty and diversity in decision-making, the fuzzy set theory and group decision-making technique are used in the super-matrix approach of ANP. From the requirements of manufacturer, the data envelopment analysis (DEA) approach is applied to adjust the initial weights of ECs taking into account business competition and implementation difficulty. A case study is carried out to demonstrate the effectiveness of the developed integrated approach for prioritizing ECs in PSS conceptual design.  相似文献   

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As an emerging IT-driven business paradigm, smart product-service system (Smart PSS), which offers not only the smart, connected product (SCP) but also its generated service as a solution bundle, has become a vital research topic. Many research efforts have been devoted to constructing the conceptual design framework by considering SCPs and services simultaneously. However, the following critical issues in Smart PSS conceptual design have not been well addressed: how to improve the solution of Smart PSS in the conceptual design stage to meet user emotional requirements. Aiming to fill the gap, this work proposes a conceptual design method for Smart PSS from the perspective of analyzing user-generated emotions/feelings. Specifically, the relevant traditional products are identified, and their public review data is used to analyze user emotions/feelings in user-product interaction. Interactive emotion board as a new design tool is presented to organize the user-generated emotions/feelings, associated design elements, and the potential design points of the initial solution. And the analytic hierarchy process (AHP) is utilized to evaluate the improved solution. To ensure the efficiency of the analysis process, the self-organizing map (SOM) algorithm is utilized in the process of clustering product samples and Kansei words. A case study of smart electric bicycle service system (SEBSS) design is used to demonstrate the performance of the proposed method. Based on the case study, the proposed approach appears effective in helping with Smart PSS conceptual design.  相似文献   

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This paper enables the rapid creation and modification of freeform surfaces inside an augmented reality environment, and focuses on methods for enabling increased flexibility during exploratory, conceptual industrial product design through three-dimensional (3D) sketch-based user input. Specifically, we address the role of multiple shape representations with varying uncertainty levels during 3D conceptual sketching, along with methods to transform between those representations. The main contributions of this work are: (1) the formulation of virtual shape data in multiple, concurrent representations (points and surfaces), and a regression method to transition fluidly back and forth between these representations during design, (2) methods for deforming and exploring the product shape using these multiple representations, and (3) representations of these forms such that designers can explore conceptual designs without the need for detailed surface operations such as trimming or continuity enforcement. Through incorporating these contributions, we introduce techniques that can be incorporated in future computer-aided conceptual design systems. These contributions are demonstrated for freeform surface design, with examples of computer mouse and car seat exterior surfaces.  相似文献   

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Database and data model evolution cause significant problems in the highly dynamic business environment that we experience these days. To support the rapidly changing data requirements of agile companies, conceptual data models, which constitute the foundation of database design, should be sufficiently flexible to be able to incorporate changes easily and smoothly. In order to understand what factors drive the maintainability of conceptual data models and to improve conceptual modelling processes, we need to be able to assess conceptual data model properties and qualities in an objective and cost-efficient manner. The scarcity of early available and thoroughly validated maintainability measurement instruments motivated us to define a set of metrics for Entity–Relationship (ER) diagrams. In this paper we show that these easily calculated and objective metrics, measuring structural properties of ER diagrams, can be used as indicators of the understandability of the diagrams. Understandability is a key factor in determining maintainability as model modifications must be preceded by a thorough understanding of the model. The validation of the metrics as early understandability indicators opens up the way for an in-depth study of how structural properties determine conceptual data model understandability. It also allows building maintenance-related prediction models that can be used in conceptual data modelling practice.  相似文献   

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A Methodology for Data Schema Integration in the Entity Relationship Model   总被引:1,自引:0,他引:1  
The conceptual design of databases is usually seen as divided into two steps: view modeling, during which user requirements are formally expressed by means of several user oriented conceptual schemata, and schema integration, whose goal is to merge such schemata into a unique global conceptual schema. This paper is devoted to describe a methodology for schema integration. An enriched entity relationship model is chosen as the data model. The integration process consists of three steps: first, several types of conflicts between the different user schemata are checked and solved; second, schemata are merged into a draft integrated schema, that is, third, enriched and restructured according to specific goals.  相似文献   

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Reducing the impact of conflicts on requirement-function-structure mapping in the early stage of product design is an important measure to achieve conceptual innovation, which relies on accurate reasoning of multi-domain knowledge. As product requirements become more personalized and diverse, traditional discrete knowledge organization and reasoning methods are difficult to adapt to the challenges of continuity and precision in conceptual solution. Knowledge graphs with complex networks have obvious advantages in association detection, knowledge visualization, and explainable reasoning of implicit knowledge, which offer innovative opportunities for conflict resolution in conceptual design. Therefore, a smart conflict resolution model using a multi-layer Knowledge Graph for Conceptual Design(mKGCD) is proposed in this study. A knowledge expression form of FBS-oriented design patent vocabulary is proposed, which is used for knowledge entity recognition and relation extraction based on natural language processing. A label mapping method based on inventive principles is used for patent classification and a four-layer semantic network for conflict resolution is constructed. Through semantic distance calculation, the designer's requirements for function/behavior/structure are smart deployed to obtain appropriate knowledge. A case study of the conceptual design of a collapsible installation and handling equipment demonstrates the feasibility of the proposed approach. The proposed method can not only meet the functional solution and innovation in the context of different design requirements, but also effectively improve the design efficiency in the iterative design process by means of multiple meanings of one graph.  相似文献   

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一种面向方案设计的装配建模表示方法   总被引:20,自引:3,他引:17  
CAD系统对方案设计支持的关键是建立独立于几何细节而又表达的功构关系的装配模型,本文试图运用逻辑装配单元的定义来实现产品功能需求和结构表现间的有效关联,分别讨论了方案设计中功能描述和几何构形表示方式,形式化表达了方案设计的逻辑造型和装配建模过程,给出了支持自顶向下方案设计的装配模板定义,为方案设计的计算机辅助实现作了有益的尝试。  相似文献   

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