面向制造的CAD建模方法研究

基于CAD／CAPP／CAM一体化的思想。在充分利用现有CAD软件的基础上,深入分析了设计特征与制造特征的相互关系。研究制定了工程语义上而不仅仅是几何与拓扑意义上正确的三维CAD建模规则。给出了典型零件的建模实例。     

一种基于离散小波基的压缩传感测量矩阵优化方法

测量矩阵优化是压缩传感理论(CS)研究的重要内容,基于离散小波基,提出一种测量矩阵优化算法.根据离散小波变换的系数分布特点,构建优化矩阵来对原测量矩阵系数进行调整,提高了采样效率,同时降低了测量矩阵列向量的相干性.理论分析和实验验证表明,该优化算法对压缩传感中常用测量矩阵进行优化后,其重建效果都有所提高,特别是在低采样率的条件下,优化效果明显.经过验证,优化后的测量矩阵满足有限等距特性(RIP).     

上海磁悬浮列车工程基岩水准标设计与施工

上海磁悬浮列车工程专门设计施工了两座基岩水准标，作为沉降监测的测量基准。该基岩标较以往监测标志有重大改进，并兼有高程控制与平面位置控制的作用。本文介绍其设计原理、结构特点与施工技术。     

三坐标测量机测量同轴度误差的方法探讨

文章讨论了利用三坐标测量机测量同轴度误差的方法,并给出了各种方法之间的区别.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

浦东国际机场基岩水准标设计与施工

浦东国际机场因工程建设与正常航运所需，先后设置了两座基岩水准标，作为高程控制测量基准。现介绍基原理与施工技术。     

Towards ITS Map Database Interoperability—Database Error and Rectification

One of the impediments to the implementation of ITS is the lack of map database interoperability. Centreline databases are available from a number of sources, but few were designed specifically for ITS. Consequently there are a variety of problems—coordinate inaccuracy, errors of omission and commission, missing or wrong street names, incorrect topology—that are compounded when communicating parties use databases from different vendors. Many ITS applications (e.g., emergency response, ATIS) rely on the exchange of messages in which location is a component. Map error and interoperability problems can result in a variety of practical difficulties, from inappropriate vehicle routing to delays in delivery of critical services. These problems can be addressed by (a) standards for map databases, (b) intelligent messaging, (c) national integration efforts to improve database quality in the long term. This paper examines the dimensions of the problem, and describes solutions currently under development.