【作者】 王凤英；

【导师】 陈奎生； 应保胜；

【作者基本信息】 武汉科技大学 ， 机械电子工程， 2004， 硕士

【摘要】 在市场经济高速发展的今天，企业间的竞争日趋激烈，如何减少产品的成本、增加市场应变能力及快速反应能力成为了企业追求的主要目标。传统的企业报价要么是基于经验的随意估价，要么需要等到产品设计完成后再计算价格，存在报价慢、缺乏科学依据、缺乏市场应变能力等缺点。为了这种解决报价存在的不足，利用因特网技术和智能产品方案设计方法，根据用户需求，快速实现产品的方案设计，并在此基础上对产品进行灵活、快速、科学报价，这也是今后企业网上报价的发展方向，基于实例推理的产品概念设计正是这一方向的体现。本课题作为机电产品的网上快速报价系统的子课题。其主要目的是开发一个基于实例推理的产品概念设计系统，为进行机电产品的网上快速报价系统的开发提供理论依据，使得企业报价科学、快速、准确。 提出了一种面向对象模型的知识表示方法，是在原有关系型数据的基础上进行数据模型的抽象。并将之应用在减速器概念设计系统中，证明了此方法可以有效地解决复杂结构的知识表示，又可以有效地屏蔽底层数据库，具有一定的移植性。 探讨了概念产品实例的分类网模型，使用粗糙集理论来计算产品实例中关键特征属性的重要性，解决相似度量中的特征属性的权重值问题。提出了一种实例检索策略及算法。即就是在最邻近策略与知识导引策略结合的基础上来进行对产品概念设计实例的索引。先用知识引导策略建立知识索引项，再在最邻近策略的基础上直接采用相似度计算公式算出新问题和实例库中所有实例的相似度，再由相似度排序进行最佳相似实例的检索，这种方法简单有效。 用Access 2000建立模拟概念产品设计实践的相似实例库模型。用Visual BasiC. NET作为编程语言，对实例库编程，建立可视化检索界面。实现减速器概念产品的相似实例的快速检索。通过本系统在减速器概念产品设计的应用，表明基于实例模型的实例推理是一种高效的实例推理方法，在产品概念设计中取得了满意的结果，为产品的网上报价系统提供了科学的、合理的依据。更多还原

【Abstract】 With the rapid development of market economy, the competition between enterprises becomes more and more vigorous. How to reduce the cost of product, increase the abilities to meet an emergency of market and fast reaction. Those become the main target of enterprises. Quote price of the traditional enterprises is based on experience, or the price is accounted after accomplishing the product design. There are some shortcomings such as slowing down the quoted price, lack of scientific foundation, lack of the ability of meeting an emergency of market. In order to resolve those shortcomings, utilize the network techniques and intelligent product planning design method, according to the needs of customers, realize the fast planning design of product. This thesis is a part of fast quote systems for electromechanical product. The main purpose of this thesis is to exploit a system for product conceptual design that is based on case-based reasoning technology, and supply a theoretic foundation for this system, which makes the quote system scientific, quick and accurate.It puts forward a knowledge representation method of object-oriented model, which is abstracted from the relational data. It is applied in the conceptual design systems of deceleration machine. It is proved that the method could resolve the complicated and structural knowledge representation effectively and screen the bottom database effectively. So it can be transplanted.This thesis discusses the classification network model of conceptual product cases, uses the Roughset theory to determine the importance of each key feature and answers the question of heavy value in power of key case feature in similarity measurement. It puts forward a case retrieve strategy and algorithm; that is to say, retrieve the cases by the combination of the nearest approach and the knowledge-based retrieve approach. Firstly, establishes the knowledge index item with knowledge-based retrieval approach. Secondly, accounts the degree of similarity of all cases in the case database and the new problem with formula of computation of the degree of similarity on the base of the nearest neighbor approach. Finally, retrieves the best similar case by sorting the degree of similar case.It uses the Access 2000 to establish the similar case-base model to simulate conceptual product. As programming language, the Visual Basic.NET programs the case-base and establishes the visualized retrieve interface. That realizes the quick index of the similar case of the deceleration machine conceptual product. The system is applied in the product conceptual design of deceleration machine. It has been proved that the case-based model reasoning is an effective reasoning method. The satisfying result is acquired in product conceptual design. That provides scientific and logical basis for the quote system in network.更多还原