建立一种设计过程数据的获取和管理结构——设计过程数据模型。设计过程数据包括产品数据、过程数据和过程管理数据。建立设计过程数据模型的原则是便于数据展示、共享、复用和知识提取。采用XML技术管理的设计数据具有平台及语言的无关性和独立性，非常适合于表示数据、概念和上下文，并能很方便地被不同的使用者在不同的环境下重复使用，便于网络上的传输与共享，并可供整个产品生命周期重用。设计数据模型已在一个基于过程的计算机辅助设计软件原型系统中实现。

建立了一个基于整个产品设计过程的计算机辅助设计模型，该模型综合了设计矩阵、功能方法树、产品结构树和IDEF3模型的优点，并能集成第三方工具，支持设计者完成整个设计过程的活动和任务，能够获取和结构化设计过程数据。统一的设计数据模型使设计过程数据在整个产品生命周期中共享。建立了一个采用Java+XML技术的软件原型系统用来验证模型的实用性。

This paper describes in two parts a new method and device for measuring motion accuracy of numerical control (NC) machine tools. In the first part, the measurement principle and the characteristics of the prototype device are proposed. The device consists of a double-bar linkage with two rotary encoders. The working range of the device is disc-shaped with a radius of almost the double the link length, except a small area around the centre of the disc and an outer area both around the change points of the linkage at the centre and the circumference of the disc. Because the method has high resolution for any measuring point within the working range, it can be applied to measure most items of motion accuracy of NC machine tools. The method is particularly suitable to measure the trajectory accuracy of circular motions. The device has a compact structure and its installation on a machine tool to be measured is simple and quick. The experimental results show that the prototype device has very good response to small displacement and good repeatability with high precision to the measurement of circular motion trajectories. The influence of measurement noise is hardly observed in the experimental results.

This paper presents a method that applies XML technology to structure the design process data of products. The design process data includes product data, process data and process management data. Applying XML technology can build a structural and platform-independent Design Data Model (DDM), and make it possible to reuse design data in the life cycle of a product. DDM is based on a Process-based CAD (PCAD) model and a software prototype based on PCAD has been developed using Java and XML technologies that are platform independent. A Document Object Model (DOM) technology is used to operate XML documents and an example is presented to demonstrate this method.