Knowledge-based automation of a design method for concurrentsystems

This paper describes a knowledge-based approach to automate a software design method for concurrent systems. The approach uses multiple paradigms to represent knowledge embedded in the design method. Semantic data modeling provides the means to represent concepts from a behavioral modeling technique, called Concurrent Object-Based Real-time Analysis (COBRA), which defines system behavior using data/control flow diagrams. Entity-relationship modeling is used to represent a design metamodel based on a design method, called COncurrent Design Approach for Real-Time Systems (CODARTS), which represents concurrent designs as software architecture diagrams, task behavior specifications and module specifications. Production rules provide the mechanism for codifying a set of CODARTS heuristics that can generate concurrent designs based on semantic concepts included in COBRA behavioral models and on entities and relationships included in CODARTS design metamodels. Together, the semantic data model, the entity-relationship model, and the production rules, when encoded using an expert system shell, compose CODA, an automated designer's assistant. CODA is applied to generate 10 concurrent designs for four real-time problems. The paper reports the degree of automation achieved by CODA. The paper also evaluates the quality of generated designs by comparing the similarity between designs produced by CODA and human designs reported in the literature for the same problems. In addition, it compares CODA with four other approaches used to automate software design methods     

基于知识重用的服装CAD系统

针对当前CAD软件对设计知识重用支持不足且大多基于WIMP交互方式等问题,设计并实现一个基于知识重用的服装工艺设计系统。该系统框架主要包括知识推荐和知识编辑2个模块。针对知识推荐和知识编辑,分别提出基于草图相似性的实时知识推荐算法和基于笔手势的知识编辑方法,给出系统的应用实例。该系统已应用于北京某羊绒企业的生产中,实践表明该系统能改善人机交互,提高设计效率。     

A function-centered framework for reasoning about system failure at multiple levels of abstraction

This paper presents the knowledge organization for a simulation subsystem that is a component of a comprehensive expert system for failure modes and effects analysis. Organizing the simulation subsystem's knowledge base around a function-centered ontology produces an architecture that facilitates reasoning about an engineering design at multiple levels of abstraction and throughout the life-cycle of the design. Moreover, the resulting architecture provides the capability for incorporating computer-aided analysis and design tools early on into the conceptual design of an engineering system before a commitment is made to a specific technology to implement the system's behavior. The result is an expert system simulation knowledge source that can be used to reason about the effects of system failures based on conceptual designs, i.e. designs in which commitments to an underlying technology to achieve the system's function have not yet been made but computer-aided assistance for reasoning about the system's potential failure modes and effects is useful.     

Transactional blackboards

Using the blackboard architecture, an expert system is built as a collection of knowledge sources which are scheduled by a controller and communicate through a shared data region, called a blackboard. The performance of such a system may be significantly enhanced by the concurrent execution of the knowledge sources. However, introduction of concurrent execution into blackboard systems requires extension of the architecture with new mechanisms for scheduling knowledge source activities, synchronizing knowledge source interactions, and accessing shared data. This paper describes our design for transaction-based facilities supporting parallel execution of knowledge sources in a blackboard system.     

基于组件的办公自动化管理系统的分析与设计

办公自动化系统能够极大程度地改进知识共享,节省宝贵的资源并提高组织的效率.本文通过与以往设计方案的比较,分析了采用基于组件的多层分布式结构的优越性,讨论了在系统实现过程中所使用的关键技术和开发重点,并对系统各个模块的功能做了详细的设计.     

A knowledge intensive multi-agent framework for cooperative/collaborative design modeling and decision support of assemblies

Multi-agent modeling has emerged as a promising discipline for dealing with decision making process in distributed information system applications. One of such applications is the modeling of distributed design or manufacturing processes which can link up various designs or manufacturing processes to form a virtual consortium on a global basis. This paper proposes a novel knowledge intensive multi-agent cooperative/collaborative framework for concurrent intelligent design and assembly planning, which integrates product design, design for assembly, assembly planning, assembly system design, and assembly simulation subjected to econo-technical evaluations. An AI protocol based method is proposed to facilitate the integration of intelligent agents for assembly design, planning, evaluation and simulation process. A unified class of knowledge intensive Petri nets is defined using the O-O knowledge-based Petri net approach and used as an AI protocol for handling both the integration and the negotiation problems among multi-agents. The detailed cooperative/collaborative mechanism and algorithms are given based on the knowledge objects cooperation formalisms. As such, the assembly-oriented design system can easily be implemented under the multi-agent-based knowledge-intensive Petri net framework with concurrent integration of multiple cooperative knowledge sources and software. Thus, product design and assembly planning can be carried out simultaneously and intelligently in an entirely computer-aided concurrent design and assembly planning system.     

Design and manufacturing advisor for turbine disks

The design and manufacturing advisor (DMA) is a generic architecture for an expert system which assists in the process of product design. It integrates various parts of the production environment which affect the final product—such as fabrication, assembly, inspection and inventory. The design process can be partitioned into four stages: problem specification, feature specification, testing and generation. DMA facilitates the development of tractable designs, defined by the intersection of three spaces relating to specifications, features and productibility. The system consists of a domain-independent module and a domain-dependent module, each of which contains subcomponents; this modular structure facilitats system modification, expansion, and portability. The DMA has been validated by specializing the architecture to the design of gas-turbine disks for jet engines.     

基于虚拟样机的复杂产品协同设计与仿真关键技术研究

主要研究并行工程环境下复杂产品虚拟样机协同设计与仿真的体系结构及其关键技术。提出虚拟样机协同设计与仿真系统的体系结构与整体解决方案,研究面向虚拟样机的数字化多领域集成建模理论与方法,建立面向虚拟样机开发全生命周期的集成过程管理与冲突协调模型,提出面向复杂产品虚拟样机开发的多学科协同设计、协同仿真和智能决策支持的理论与方法,建立复杂产品虚拟样机协同支持环境,有效提高企业创新能力和核心竞争力。     

An in-process customer utility prediction system for product conceptualisation

Customer involvement in new product development, especially in the early stage of product conceptualisation, plays an important role for a successful product. In this study, a customer utility prediction system (CUPS) is proposed. The system comprises two modules, namely design knowledge acquisition module and customer utility evaluation module. In the design knowledge acquisition module, a knowledge acquisition technique called general sorting is utilised to establish a design knowledge hierarchy (DKH), in which design options can be generated. In the same module, customer voices towards diverse design options called customer-sensitive design criteria are solicited from customer requirements. Subsequently, in the customer utility evaluation module, a measurement for customer desirability, i.e. customer utility index (CUI), is formulated using conjoint analysis (CA) technique. Finally, the rated criteria are also used as inputs to a radial basis function (RBF) neural network for in-process customer utility prediction. A case study on cellular phone design is used to illustrate the proposed approach.     

特定领域软件复用技术的研究与应用

围绕特定领域软件体系结构的设计,利用平台化分层体系结构的设计思想以及应用集成设计机制,对面向领域的软构件开发模型进行了探讨与设计,并以某石油公司企业MIS的设计为开发背景,选取其中一个特殊的子系统模块,对业务构件的组合过程——复用技术进行了详细的设计与阐述。     

BDES: A bridge design expert system

The expert system described here designs superstructures for small to medium span highway bridges. The system addresses a domain within the engineering design consultation paradigm. It is installed in a personal microcomputer environment. This paper examines the nature of the bridge design domain as practiced in the United States and its suitability for expert system application. The architecture, the context structure, the knowledge base, the control module, and the implementation of the expert system are presented.     

An object-oriented knowledge based Petri net approach to intelligent integration of design and assembly planning

Artificial intelligence can play an important role in the reduction of manufacturing costs and the enhancement of production efficiency and product quality. In order to assist designers in the early stages of a product development this paper develops an intelligent methodology for integration of design and assembly planning processes, including product design, assembly evaluation and redesign, assembly process planning, design of assembly system and assembly simulation, subjected to both econo-technical and ergonomic evaluations. A new unified class of object-oriented knowledge based Petri nets called OOKPNs, incorporating knowledge based expert systems and fuzzy logic into ordinary place–transition Petri nets, is defined and used for the representation and modeling of the distributed design processes. A prototype intelligent integrated design and assembly planning system (IIDAP) is implemented through distributed blackboard structure with concurrent integration of multiple cooperative knowledge sources and software. It consists essentially of the networked agents and the meta-system, each of which is a knowledge Petri net system with the capabilities of problem solving, learning and conflict resolution, and can be obtained through the inheritance, polymorphism and dynamic binding of instances of OOKPNs. In IIDAP system, both C/C++ language and COOL (CLIPS object-oriented language) are used to incorporate a Petri net tool, a geometric modeling and design tool, a planner and simulator and an evaluation tool. By use of this system, product design and assembly planning can be carried out simultaneously and intelligently in an entirely computer-aided concurrent design and assembly planning system. The design of manufacturable, cost-effective, usable products can therefore be achieved rapidly and flexibly. The developed methodology and system have been successfully applied to assembly design and planning of a micro switch.     

基于虚拟样机的复杂产品协同设计与仿真关键技术研究*

主要研究并行工程环境下复杂产品虚拟样机协同设计与仿真的体系结构及其关键技术。提出虚拟样机协同设计与仿真系统的体系结构与整体解决方案,研究面向虚拟样机的数字化多领域集成建模理论与方法,建立面向虚拟样机开发全生命周期的集成过程管理与冲突协调模型,提出面向复杂产品虚拟样机开发的多学科协同设计、协同仿真和智能决策支持的理论与方法,建立复杂产品虚拟样机协同支持环境,有效提高企业创新能力和核心竞争力。     

An Expert System Realization for Conceptual Design of Mechanical Products

Through the practice of developing an expert system FBCDES(Feed Box Conceptual De-sign Expert System)for the planomillingmachine in CIMS ERC(CIMS Engineering Research Center)in China,the paper intends to introduce a common problem-solving strategy for the mechanical productconceptual design expert system.Meanwhile some problems such as system architecture,knowledgerepresentations and inference engine sets are also described.A yet more detailed discussion is given tothe technical problems for realizing two key modules,that is concept design module and layout module.     

Development of a computer-aided concurrent net shape product and process development environment

This paper presents a systematic approach to developing a collaborative environment for computer-aided concurrent net shape product and process development. This approach includes the steps of (1) conventional development process analysis, (2) development process re-engineering, (3) computer-based system functional requirements analysis, (4) system framework design, and (5) system modeling, integration and implementation. This environment can support concurrent net shape product and process development by providing and integrating functions of product data management, process management and development advisory tools. The results of this research will facilitate the rationalization and automation of net shape product and process development and thus improve the efficiency and quality, and reduce the cost of net shape product development.

IDEF structural analysis methodology was employed to capture the characteristics of net shape product and process development process. The concept of concurrent engineering was used to re-engineer the development process. The technology of system engineering was used to design the computer-aided system framework. Object-oriented analysis, modeling and design methodology, knowledge engineering and data engineering techniques were employed for system modeling and implementation.     

An Internet-based intelligent design system for injection moulds

The rapid growth of Internet and information technologies in recent years provides a solution to support and facilitate collaborative product developments among different geographically distributed enterprises. An effective and feasible tool to aid the collaborative development of injection moulds can be realized by developing an Internet-based mould design system as one of the modules of a collaborative product development system. This paper presents a prototype Internet-based intelligent design system for injection moulds. The architecture of the system consists of an interactive KB mould design system embedded in an Internet environment. A Java-enabled solution together with artificial intelligence techniques is employed to develop such a networked interactive CAD system. In this system, the computational module, the knowledge base module and the graphic module for generating mould features are integrated within an interactive CAD-based framework. The knowledge base of the system would be accessed by mould designers through interactive programs so that their own intelligence and experience could also be incorporated with the total mould design. The approach adopted both speeds up the design process and facilitates design standardization which in turn increases the speed of mould manufacture. A practical case study is presented to illustrate the operations of the Internet-based mould design system.     

A QFD-enabled product conceptualisation approach via design knowledge hierarchy and RCE neural network

In this paper, an approach that attempts to improve conventional quality function deployment (QFD) technique in terms of effective design knowledge handling in product concept development is proposed and described. For this purpose, a QFD-enabled product conceptualisation system was established. It consists of three cohesively interacting modules, namely, design knowledge elicitation module using laddering technique, design knowledge representation module using design knowledge hierarchy (DKH), and design knowledge organisation module using restricted Coulomb energy (RCE) neural network. A case study on wood golf club design was used to illustrate the performance of the proposed approach. From the case study, the prototype QFD-enabled product conceptualisation system has demonstrated its effectiveness in design knowledge acquisition, representation and organisation at an early stage of NPD. The details of the validation are discussed.     

Towards computer-aided configuration design for the life cycle

In modern design, life-cycle concerns such as recycling and service are receiving increased attention. The configuration design phase, where the product and component structure is established, is of particular importance when designing for the life cycle. In this paper, the foundation for a CAD system supporting configuration design for the life cycle is presented. A prototypical CAD system, called CODA (Configuration Design of Assemblies), is under development based on this foundation. A discussion on the supported product and component representation is given, followed by a portrayal of some of the capabilities to support life-cycle design. Specifically, requirements are identified for the information needed to support design for assembly, disassembly, service, recycling, and reuse. A case study involving the (re)design of a hand-held tape recorder with respect to improved disassemblability and recyclability is utilized to highlight some of the capabilities of the current system. With the new product and component representation embodied in CODA, improved support over current CAD systems is provided for configuration design and life-cycle design assessments.     

通用嵌入式系统软件测试平台的设计

仿真测试是嵌入式软件系统测试阶段的一种有效测试方法,探讨了通过在PC机上仿真模拟ARM嵌入式系统,对嵌入式系统软件进行仿真测试的通用测试平台的设计。该平台可以在不做大幅度修改的情况下对不同的嵌入式系统软件进行各种测试。重点介绍了仿真模拟器、测试管理器和测试平台专用工具链的设计,提出了一种测试管理器的实现模型,并进行了详细的描述。     

FRS模块设计及其协作关系

容灾系统的基础是实现数据在线复制。论述FreeBSD平台数据复制系统(FRS)的结构,给出其模块设计和模块间的协作关系。设计并实现一种FRS,其中嵌入了通用复制设备驱动层。该系统不依赖具体的存储设备或逻辑卷管理器,具有很强的独立性、灵活性和通用性,能实现数据块级别的复制。