rried out. The Lagrange multipliers are

boundary conditions. A cell structure which is independent to the nodes is used to evaluate the integrals of EFG     

Utilization of STEP AP 210 at The Boeing Company

Boeing has been working on the development and implementation of STEP AP 210 since its inception. Using a combination of internally funded activities, external government contracts and multi-company pilots, Boeing has developed prototype tools to utilize AP 210 and is poised to move these tools into production. This paper begins with a brief overview of STEP and AP 210. The status of available AP 210 vendor translators (data generators), along with viewers and analysis programs (data consumers) is covered. Discussion continues with present and planned usage of AP 210 in several companies with the primary emphasis on implementation at The Boeing Company. The document concludes with a summary of key points.     

A study on time schemes for DRBEM analysis of elastic impact wave

 The precise integration and differential quadrature methods are two new unconditionally stable numerical schemes to approximate time derivative with more than the second order accuracy. Recent studies showed that compared with the Houbolt and Newmark methods, they produced more accurate solutions with large time step for the problems where response is primarily dominated by low and intermediate frequency modes. This paper aims to investigate these time schemes in the context of the dual reciprocity BEM (DRBEM) formulation of various shock-excited scalar elastic wave problems, where high modes have important affect on traction response. The Houbolt method was widely recommended in many literatures for such DRBEM dynamic formulations. However, this study found that the damped Newmark algorithm was the most efficient and accurate for impact traction analysis in conjunction with the DRBEM. The precise integration and differential quadrature methods are shown inapplicable for such shock-excited problems due to the absence of numerical damping. On the other hand, we also found that to achieve the same order of accuracy, the differential quadrature method required much less computing effort than the precise integration method due to the use of the Bartels–Stewart algorithm solving the resulting Lyapunov matrix analogization equation. Received 6 November 2000     

现场总线技术在发电系统数据采集中的应用

介绍了现场总线网络在干熄焦汽轮机发电生产过程中所起的作用，并重点介绍了系统所完成的数据采集，监视和管理等功能。     

机电一体化技术在综合采煤设备中的应用与发展

介绍了机电一体化技术在国内外煤矿井下综采设备中的应用，并论述了机电一体化技术发展与相关技术的研究。     

城市现有地下管线探查及数据处理方法探讨

该文根据城市地下管线探查及数据处理方法现状 ,结合管线管理单位需要 ,对地下管线探查及数据处理方法中的有关问题进行了探讨 ,供今后管线探测工作借鉴     

未来十年综合航电系统的发展趋向

本文主要阐述未来十年国外综合航电系统的总的发展趋向，重点介绍了在开放式系统结构的研究与应用、采用COTS技术、模块化、多传感器综合技术等方面的发展趋向。     

The optimisation of higher order resampling methods in a multiprocessor environment

The processing of images obtained from satellites often involves highly repetitive calculations on very large amounts of data. This processing is extremely time consuming when these calculations are performed on sequential machines. Parallel computers are well suited to handling computationally expensive operations such as higher order interpolations on large data sets. This paper decribes work undertaken to develop parallel implementations of a set of resampling procedures on an Alliant VFX/4. Each resampling procedure implemented has been optimised in three stages. First, the algorithm has been restructured, where two-dimensional resampling is performed by two one-dimensional resampling operations. Second, each procedure has been reprogrammed in such a way that the autoparallelisation provided by the FX/Fortran compiler has been exploited. Thirdly, data dependent analysis of each procedure has been performed in order to achieve full optimization of each procedure; each procedure has been restructured where appropriate to circumvent vectorisation and concurrency inhibiting data dependencies. The nature and extent of the code optimization achieved for each procedure is presented in this paper. The original code for the most computationally expensive procedure, as targeted at a sequential machine, was found to have an execution time of 4900 seconds on the Alliant VFX/4 when compiled with regular compiler optimization options. Following algorithmic redesigning and reprogramming of the code, as indicated in stage 1 and stage 2, the execution time was reduced to 248 seconds. Restructuring of the code following data dependency analysis indicated in stage 3 in order to avoid data dependencies and allow concurrency and vectorisation, further reduced execution time to 162 seconds. The consequence of this work is that higher-order resampling methods which had not previous been practical are now routinely performed on the Alliant VFX/4 at the University of Dundee.     

热释电系数的测量方法

描述热释电系数的两种测量方法。其一为电荷积分法，测试系统简单，测量数据准确，且能满足零电场条件下的测量。其二为动态电流法，采用调制热源技术，研究在特定温度条件下热释电材料的动态热释电响应。     

水文自动测报系统防雷的探讨

水文自动测报系统若配备有线／无线（GSM，GPRS）双通道，可提高系统的可靠性，保证系统的畅通。然而，有线组网方式最致命弱点是防雷能力差，针对防雷问题，在实践中探讨其有效途径，论述接地装置的设计、安装中应注意的几个问题，并介绍在实践中电话线防雷从一级防护发展到三级防护，提高防雷的效果，有待在实践中，再认识，再提高。