产品数据管理(Product Data Management,PDM)是近年来出现的一项新技术,其主要功能包括电子仓库和文档管理、产品流/设计过程管理、产品结构与配置管理、生命周期(工作流)管理和集成开发接口.他将整个企业视为一体,跨越整个工程技术群体,快速地开发产品和转化业务过程,也是在分布式企业管理模式的基础上,与其他应用系统建立直接联系的重要工具.在应用过程中,要全面、正确地认识PDM,根据市场发展需要动态建立对象模型,重视咨询、注重配合. 相似文献
A novel method which can detect the possible handoffs for mobile nodes is proposed in this article. The method can be deployed on mobile nodes. So when a possible handoff occurs, mobile nodes can detect and take some necessary actions in time. In this study, the method is also used to optimize the transmission mechanism of Q-TCP. Moreover, the simulation results show that Q-TCP can provide better quality of service （QoS） for mobile nodes when they are moving among different agents. 相似文献
Some years ago, compactly supported divergence-free wavelets were constructed which also gave rise to a stable (biorthogonal) wavelet splitting of . These bases have successfully been used both in the analysis and numerical treatment of the Stokes and Navier-Stokes equations. In this paper, we construct stable wavelet bases for the stream function spaces . Moreover, -free vector wavelets are constructed and analysed. The relationship between and are expressed in terms of these wavelets. We obtain discrete (orthogonal) Hodge decompositions.
Our construction works independently of the space dimension, but in terms of general assumptions on the underlying wavelet systems in that are used as building blocks. We give concrete examples of such bases for tensor product and certain more general domains . As an application, we obtain wavelet multilevel preconditioners in and .
