基于PC的一种新型现场总线控制系统

PC性能的不断提高及实时操作系统内核的出现，促使了一种基于PC和现场总线的新型控制系统的诞生。由于该系统成本低，占用空间少，在联网、监控等方面有突出优点，并且PC机性能已经非常可靠，所以它可以取代传统的PLC来完成实时控制任务。为了验证系统的可行性，文章系统地介绍了这类新型控制系统的优点和整体软硬件结构，并对其中一个重要的性能指标——响应时间，进行了详细分析，然后通过一个实际系统——自动传输线系统，验证了这一控制系统的可行性。

基于PC的一种新型现场总线控制系统

PC性能的不断提高及实时操作系统内核的出现,促使了一种基于PC和现场总线的新型控制系统的诞生。由于该系统成本低,占用空间少,在联网、监控等方面有突出优点,并且PC机性能已经非常可靠,所以它可以取代传统的PLC来完成实时控制任务。为了验证系统的可行性,文章系统地介绍了这类新型控制系统的优点和整体软硬件结构,并对其中一个重要的性能指标——响应时间,进行了详细分析,然后通过一个实际系统——自动传输线系统,验证了这一控制系统的可行性。

基于人工神经网络的PC钢棒力学性能预报模型

提出一种PC钢棒抗拉强度的人工神经网络模型方法,采用4×9×1的三层前向BP网络结构,模型主要因素为淬火温度、回火温度、含碳量和单位长度质量。经1500余次训练后,误差平方和

WAGO750模块与PC机之间的通讯

介绍了一种用于WAGO750-842以太网节点及系列模块与PC机之间的一种通用而又简便的通讯方法,该方法能够使PC机与WAGO750系列模块方便地进行数据交换,从而达到计算机对控制对象进行信息采集和控制输出的目的。该方法已在载人潜水器控制系统中得到成功应用,效果良好。

基于PC平台的机器人控制设计与实现

本文首先回顾了机器人控制器的发展历史,重点介绍了我们承担的国家八六三课题“基于PC高档机器人控制器开发”的研制情况.该控制器具有开放、模块化、可靠、高效、通用的特点.

基于工业PC和PLC技术的料架指示系统

本文介绍了一个应用于变速箱装配生产线的料架指示系统的主要功能,阐述了系统的硬件结构和软件设计思想。

波动方程辛几何算法三维叠前深度偏移及其并行实现

Oil and scientific groups have been focusing on the 3D wave equation prestack depth migration since it can solve the complex problems of the geologic structure accurately and maintain the wave information, which is propitious to lithology imaging. The symplectic method was brought up by Feng Kang firstly in 1984 and became the hotspot of numerical computation study. It will be widely applied in many scientific field of necessity because of its great virtue in scientific sense. This paper combines the Symplectic method and the 3-D wave equation prestack depth migration to bring up an effectual numerical computation method of wave field extrapolatation technique under the scientific background mentioned above. At the base of deep analysis of computation method and the performance of PC cluster, a seismic prestack depth migration flow considering the virtue of both seismic migration method and Pc cluster has formatted. The software, named 3D Wave Equation Prestack Depth Migration of Symplectic Method, which is based on the flow, has been enrolled in the National Bureau of Copyright (No. 0013767). Dagang and Daqing Oil Field have now put it into use in the field data processing. In this paper, the one way wave equation operator is decompounded into a phase shift operator and a time shift operator and the correct item with high rank Symplectic method when approaching E exponent. After reviewing eliminating alias frequency of operator, computing the maximum angle of migration and the imaging condition, we present the test result of impulse response of the Symplectic method. Taking the imaging results of the SEG/EAGE salt and overthrust models for example and seeing about the imaging ability with complex geologic structure of our software system, the paper has discussed the effect of the selection of imaging parameters and the effectuation on the migration result of the seismic wavelet and compared the 2-D and 3-D prestack depth migration result of the salt mode. We also present the test result of impulse response with the overthrust model. The imaging result of the two international models indicates that the Symplectic method of 3-D prestack depth migration accommodates great transversal velocity variation and complex geologic structure. The huge computing cost is the key obstruction that 3-D prestack depth migration wave equation cannot be adopted by oil industry. After deep analysis of prestack depth migration flow and the character of PC cluster ,the paper put forward :i)parallel algorithms in shot and frequency domain of the common shot gather 3-D wave equation prestack migration; ii)the optimized setting scheme of breakpoint in field data processing; iii)dynamic and static load balance among the nodes of the PC cluster in the 3-D prestack depth migration. It has been proven that computation periods of the 3-D prestack depth migration imaging are greatly shortened given that adopting the computing method mentioned in the paper. In addition,considering the 3-D wave equation prestack depth migration flow in complex medium and examples of the field data processing, the paper put the emphasis on: i)seismic data relative preprocessing, ii) 2.5D prestack depth migration velocity analysis, iii)3D prestack depth migration. The result of field data processing shows satisfied application ability of the flow put forward in the paper.

Oxidative dehydrogenation of ethane to ethylene over LiCl/MnOx/PC catalysts

The catalytic stability of LiCl/MnOx/PC catalyst have been investigated, the deactivation mechanism was discussed. The experimental results show that ethane conversion decreases and ethylene selectivity keeps about 90% as reaction time increases. The main deactivation reasons of LiCl/MnOx/PC catalyst for oxidative dehydrogenation of ethane (ODHE) to ethylene are the transition of active species Mn2O3 to MnO species and the loss of arrive component Cl in catalyst. instead of ethane with FCC tailed-gas, the stability of LiCl/MnOx/PC catalyst has been largely improved.

Intellectual Property in Computing: (How) Should Software Be Protected? An Industry Perspective

The future of the software industry is today being shaped in the courtroom. Most discussions of intellectual property to date, however, have been frames as debates about how the existing law --- promulgated long before the computer revolution --- should be applied to software. This memo is a transcript of a panel discussion on what forms of legal protection should apply to software to best serve both the industry and society in general. After addressing that question we can consider what laws would bring this about.

Manejo florestal sustentado em áreas de reserva legal de pequenas propriedades rurais do PC. Pedro Peixoto-Acre.

Iniciado em meados de 1995, o projeto de manejo florestal sustentado para pequenas propriedades tem como principal característica a prescrição de uma intervenção de baixo impacto sobre a floresta por meio de "métodos artesanais" de exploração de madeira, que consideram os baixos recursos materiais disponíveis pelos pequenos produtores. A primeira parte deste documento apresenta uma descrição sintetizada da metodologia utilizada. A segunda parte apresenta as etapas já executadas e seus respectivos resultados.

Competing with CRS-generated information in the airline industry.

For over 20 years, computer reservation systems (CRSs) have been cited as a source of competitive advantage for the airlines that developed them. This paper reviews the developments that have given rise to such advantage, emphasising the use of CRS-generated information as a competitive tool within the airline industry. New evidence is presented suggesting that the control, dissemination and manipulation of CRS data by owning airlines continued to allow them to capitalise on their investment at the expense of competitors during the 1990s.

Industrial relations in the privatised coal industry: continuity, change and contradictions.

This study seeks both to describe and account for the patterns of industrial relations which have emerged in the UK coal industry since privatisation in 1994. In doing so, it also aims to address some of the wider questions concerning the relationship between ownership and industrial relations. A series of hypotheses are advanced concerning how changes in ownership might affect industrial relations within the industry, and whether such changes would have positive or negative implications for organised labour. A case study approach is utilised to analyse labour relations developments at a number of collieries, and it is shown that the industrial relations strategies adopted by management within the new coal enterprises have had a determining effect upon the patterns of labour relations within the privati sed industry. This study also demonstrates that the emergent pattern of labour relations in the privatised industry is characterised by both continuity and change. However, whilst continuity with the patterns of labour relations established during the final decade of public ownership is shown to have had negative implications for organised labour within the industry, the changes associated with privatisation are demonstrated to have been a more ambivalent force. Change has, in different contexts, had some positive implications for organised labour, but in the majority of cases, the implications for labour have been negative. Overall, therefore, this study concludes that privatisation has had a significant influence upon industrial relations within the coal industry, and that organised labour has been detrimentally affected by these developments.