CAD系统的Broker-Agent结构

BROKER-AGENT ARCHITECTURE FOR CAD SYSTEMS

本文在研究以往的以数据为中心、以执行为中心和面向对象的几类CAD系统模型的基础上，着眼于CAD系统的开放性和有效性，逐步提出了CAD系统的Broker－Agent结构，并详细研究了结构中Broker和Agent的功能实现，之后进一步分析了Broker－Agent结构对CAD系统构成的影响，最后给出了该结构的应用实例．CAD系统Broker－Agent结构的提出为更开放和更有效的CAD系统建模打下了基础．

First the definitions of openness and efficiency for CAD systems are giv-en as the goals of modeling. Then several kinds of models existed for CAD systemsare taken into consideration: data-centered model, executive-centered model andobject-oriented model. The advantages and disadvantages of these models are out-lined respectively according to openness and efficiency. Based on the object-orientedmodel, which has been broadly used by now, Broker is introduced to abate theoverall communication cost and the complexity of communication for each object,and Agent is put forth to isolate objects from communication. Now Broker-Agentarchitecture comes into being, and then the details of the functions of Broker andAgent in this architecture are further discussed. After that, the effect of Broker-A-gent architecture on extensibility of the whole system structure is also given- Final-ly, some practical issues of its application are introduced. Broker-Agent architec-ture for CAD systems is proved to be a solid base for the lmplementation of moreopen and efficient CAD systems.