PLC的大型牵伸卷绕机的应用研究

本文介绍了大型牵伸卷绕机的计算机控制系统，以西门子MMV型变频器为驱动装置，西门子PLC300为控制核心，根据西门子USS协议和MPI协议，实现PLC与变频器、TP27触摸显示屏的通信，取得了较高的控制精度和稳定性，充分满足生产过程的需要，具有广阔的应用前景。     

The design and implementation of Visuel performance monitoring and analysis toolkit for cluster and grid environments

The computing power provided by high performance and low-cost PC-based clusters with Grid platforms are attractive and they are equal or superior to supercomputers and mainframes. In this paper, we present implementation and design rationale of Visuel toolkit for MPI parallel program performance measurement and analysis in cluster and grid environments. Most of performance visualization tools available today for high-performance platforms show solely system performance data (e.g., CPU load, memory usage, network bandwidth, server average load), and thus, being suitable for computing system activity visualization. The Visuel (Visuel (in French language) = to visualize) toolkit is web-based interface designed to show performance activities of all computing nodes of a distributed environment involved in the execution of MPI parallel program, such as CPU load level and memory usage of each computing node. In addition, this toolkit is able to display comparative performance data charts of MPI parallel applications and multiple executions under investigation. The usage of this toolkit shows that it outperforms in easing the process of investigation of parallel applications.

Observer-invariant histopathology using genetics-based machine learning

Prostate cancer accounts for one-third of noncutaneous cancers diagnosed in US men and is a leading cause of cancer-related death. Advances in Fourier transform infrared spectroscopic imaging now provide very large data sets describing both the structural and local chemical properties of cells within prostate tissue. Uniting spectroscopic imaging data and computer-aided diagnoses (CADx), our long term goal is to provide a new approach to pathology by automating the recognition of cancer in complex tissue. The first step toward the creation of such CADx tools requires mechanisms for automatically learning to classify tissue types—a key step on the diagnosis process. Here we demonstrate that genetics-based machine learning (GBML) can be used to approach such a problem. However, to efficiently analyze this problem there is a need to develop efficient and scalable GBML implementations that are able to process very large data sets. In this paper, we propose and validate an efficient GBML technique——based on an incremental genetics-based rule learner. exploits massive parallelisms via the message passing interface (MPI) and efficient rule-matching using hardware-implemented operations. Results demonstrate that is capable of performing prostate tissue classification efficiently, making a compelling case for using GBML implementations as efficient and powerful tools for biomedical image processing.     

A Parallel Implementation of the Katsevich Algorithm for 3-D CT Image Reconstruction

Yu and Wang [1, 2] implemented the first theoretically exact spiral cone-beam reconstruction algorithm developed by Katsevich [3, 4]. This algorithm requires a high computational cost when the data amount becomes large. Here we study a parallel computing scheme for the Katsevich algorithm to facilitate the image reconstruction. Based on the proposed parallel algorithm, several numerical tests are conducted on a high performance computing (HPC) cluster with thirty two 64-bit AMD-based Opteron processors. The standard phantom data [5] is used to establish the performance benchmarks. The results show that our parallel algorithm significantly reduces the reconstruction time, achieving high speedup and efficiency.     

The Effect of Process Topology and Load Balancing on Parallel Programming Models for SMP Clusters and Iterative Algorithms

This article focuses on the effect of both process topology and load balancing on various programming models for SMP clusters and iterative algorithms. More specifically, we consider nested loop algorithms with constant flow dependencies, that can be parallelized on SMP clusters with the aid of the tiling transformation. We investigate three parallel programming models, namely a popular message passing monolithic parallel implementation, as well as two hybrid ones, that employ both message passing and multi-threading. We conclude that the selection of an appropriate mapping topology for the mesh of processes has a significant effect on the overall performance, and provide an algorithm for the specification of such an efficient topology according to the iteration space and data dependencies of the algorithm. We also propose static load balancing techniques for the computation distribution between threads, that diminish the disadvantage of the master thread assuming all inter-process communication due to limitations often imposed by the message passing library. Both improvements are implemented as compile-time optimizations and are further experimentally evaluated. An overall comparison of the above parallel programming styles on SMP clusters based on micro-kernel experimental evaluation is further provided, as well.     

基于MPI与PROFIBUS网络的交联生产线控制系统的设计

本文介绍西门子专用的通信网络MPI网和PROFIBUS网，并以其在交联生产线中的应用为例，阐述其特点和优势以及具体的编程和组态方式。同时，介绍了通过西门子提供的动态链接库编写程序读写PLC的数据的方法。     

柔性汽车生产线自动控制系统

为了适应汽车生产批量小,生产品种多样化和个性化的要求,设计了一套中央网络控制与分布式现场总线网络以及车身信息识别控制相结合的汽车厂柔性生产过程自动控制系统,实现了对汽车车身油漆涂装生产过程中电泳、喷漆、烘干、空调送风等12个工艺过程和车身信息识别的自动控制。针对电泳和烘干过程中的高电压、高温度特点,采用一种耐温达240℃的无线标签,实现了识别系统中车身信息的可靠传递。该套控制系统自投产以来,运行效果良好,对各工艺参数控制精度高,完全满足汽车柔性生产的要求。     

PC机集群系统在电力系统暂态稳定分析中的应用

从网络分割的角度出发,采用了一种基于支路分割的并行算法,以分割支路两端的电压为交接变量,将分割支路两端的节点看作有注入电流的节点,通过迭代最终实现并行计算。继而以MPICH.NT.1.2.5作为操作平台,利用传递函数库实现并行通讯。最后通过IEEE39节点系统对该算法进行了测试,验证了该算法的正确性,并且通过与传统算法的比较得到了令人满意的并行加速比。     

基于PROFIBUS的快锻机组网络系统

杜亚宁（1973-），女，助理工程师，主要从事设备的自动化控制技术及相关管理工作，电话：029-86514525，E-Mail：dyn@c-wst.com     

基于InfiniBand网络的MPI实现与分析

近年来,利用普通PC和高速网络搭建集群已经成为构建高性能计算环境的一种趋势。虽然InfiniBand在高性能计算领域还是相对比较新的技术,但是它的丰富特性使得它在高性能领域所占份额日趋扩大。InfiniBand Architecture(IBA)这种工业标准的主要设计思想是采用支持多并发链接的“转换线缆”技术提供高性能和高可靠性.这篇文章介绍了InfiniBand的体系结构和在InfiniBand上实现MPI的有关技术。最后在集群环境中,用MPI对InfiniBand网络的各项性能指标进行了测试。