现场总线技术的发展与工业以太网综述

本文分析了现场总线技术的现状以及发展方向，并就工业以太网作为今后现场总线技术标准的可行性进行了详细的论述，同时对TCP／IP与以太网相结合的问题进行了阐述，并提出了工业实时Ethernet即Ethernet/IP的概念以及应用前景。     

工业现场总线与无线通信的集成模式

针对工业控制环境对无线数据通信的要求 ,分析了工业环境对无线数据通信的影响 ,并就Profibus现场总线与无线LAN的几种集成模式及其特点作了分析探讨 ,最后对RFieldbus无线现场总线系统的结构和元器件集成结构作了简要介绍。     

上尚科技率先推出无线产品——让您的设备联网无限

随着全球Intemet技术的飞速发展，TCP／IP通讯技术被广泛的应用到各个行业。因为运用TCP／IP通讯技术可以无缝接人Intemet网络，这就突破距离的限制，实现远程监控或数据采集。对于工业自动化行业而言，因以太网技术出现的时间及其技术的不够成熟都不能满足工业现场需求，加上其他竞争因素，造就了目前现场总线标准不一，互不相容的局面。TCP／IP技术最大的优势就是兼容性和统一性，运用TCP／IP技术可以打破工业自动化原来总线不统一的局面，且可以接入intemet网络。     

菲尼克斯电气—开放灵活的PROFINET解决方案

PROFINET是一种真正的实时工业以太网．在一条网线上可以实现标准TCP／IP数据（TCP／IP〈100ms）、工厂实时数据（RT〈10ms）．运动控制等时同步实时数据IRT的同时传输。从应用角度上可以分为：PROFINETI／O和PROFINET CBA．同时．能够集成现有的INTERBUS、PROFIBUS、DEVICENET现场总线设备及其它工业以太网协议如：Ethernet IP．MODBUS TCP．实现工业通讯控制系统一网到底的革命。     

B＆RX20总线控制器，开启全开放的控制时代

贝加莱X20总线控制器能够兼容多个主流的现场总线，主要包括以下现场总线：Ethemet POWERLINK，EthetNet/IP，CAN CANopen，Devicenot,Profibus-DP,Profinet,Modbus TCP/IP等。同时贝加荣还推出了带有CPU性能的智能总线控制器，该类型的总线控制器在帮助用户扩展X20 I／O模块的同时．还能进行数据的采集和处理。     

内嵌TCP/IP协议的CDMA无线终端

介绍基于CDMA无线终端的TCP／IP协议实现。从CDMA无线数据通信的应用背景和应用特点出发，介绍CDMA无线终端TCP／IP协议的特殊结构，阐述应用层网络程序的开发原理，并给出实际应用系统原理及实现方法。     

ABB工业IT AC800F控制系统在红塔滇西水泥厂的应用

本文介绍ABB工业IT系统在云南红塔滇西水泥厂中的应用，该系统采用AC800F控制器，基于TCP／IP协议以太网和ProfiBus-DP／PA现场总线的网络架构。作者详细描述了该控制系统的结构和配置、采用的新技术、调试及运行效果。     

QNX下以太网现场总线多机通信的研究

在实时操作系统QNX6．20下，利用Socket API使基于Modbus TCP／IP协议的以太网现场总线实现多机通信。通过实验确定最佳的多机通信周期，以保证多机实时、可靠地控制和监测现场设备。实验结果应用于核聚变裂置极向场电源控制系统中，提高了通信实时性和稳定性。     

在现场总线控制器中实现网络通信的研究

现场总线控制系统,正以迅猛的势头快速发展,己成为目前世界上最新型的控制系统.本文是在MCU上实现TCP/IP协议,形成一个结合嵌入式系统的现场控制器.从而实现了嵌入式设备方便的接入Internet,降低了构成系统成本,是嵌入式设备接入Internet的一种尝试.本文详细描述了在现场总线控制系统中实现TCP/IP协议的过程.     

基于以太网的现场总线设备研究

将以在网应用于现场控制已成为工业控制网络发展的必然趋势。文中在研究FF协议和TCP／IP协议的基础上，建立了基于以太网的现场总线设备的模型并予以实现，进行了基本功能测试，达到了预期的效果。     

一种并行程序性能工具的研究与实现

随着高性能计算技术的不断发展,并行程序的设计、调试、优化逐渐成为并行技术应用的关键,而性能工具在提高并行程序的执行效率方面发挥着重要的作用。本文阐述了并行程序性能工具的系统结构,以及各个模块功能的原理,并实现了一个基于MPI消息统计的性能工具。     

基于构件的软件性能模型及评估技术研究

该文讲述了在基于构件的软件开发中,建立应用系统的性能模型,以及对系统的性能进行预测和评估的方法,并介绍了构建一个满足预期性能目标的软件系统的步骤。     

Prescribed performance control approaches,applications and challenges: A comprehensive survey

As to control systems, transient performance is as important as steady-state performance. For some special dynamic systems, transient performance is a more prior index in comparison with the steady-state one. Prescribed performance control (PPC) has been proved to be a powerful tool that guarantees control system outputs/errors with desired transient performance as well as steady-state performance. The purpose of this paper is to give a comprehensive review on the latest developments of PPC theories and applications. The existing performance functions are classified into five different categories, and their features are comprehensively compared, providing a useful guidance for further applications. Then, the latest developments of PPC's applications in all kinds of control systems are recalled. Specially, the faced challenges and theoretical defects of PPC are discussed, which is expected to point out the further research direction for PPC.     

On the Performance Regularity of Web Servers

The performance regularity is concerned with the overall performance behavior of a system in the full spectrum of working area. Such a performance characteristic is generally overlooked and does not receive proper attention. The aim of this paper is twofold. First, it raises awareness of the importance of the performance regularity of a Web server. Secondly, it introduces the Gini performance coefficient (GPC) as a scale-invariant metric for measuring the performance regularity. In this paper, we present the theorems that relate the performance regularity of a Web server to the GPC, thereby providing a quantitative yardstick that complements the system capacity metric such as maximum throughput for measuring the system performance. To illustrate the use of the proposed approach, we calculate the values of GPC for several representative systems that were used in the public SPECweb96 benchmark study. The results are completely in line with our theoretical analysis.     

Application of Relational Interval Arithmetic to Computer Performance Analysis: a Survey

This paper presents a survey of the existing work in the area of interval-based performance analysis of computing systems. Intervals in performance analysis is required when uncertainties or variabilities exist in the workload parameters for the performance model of the system. Intervals are also useful for computing upper and lower bounds on system performance. Most conventional analytic models accept a set of single valued parameters and produce a single valued model output. Adaptation of these existing models to handle interval parameters require new techniques that use interval arithmetic. Experiences with relational interval arithmetic provided by a constraint logic programming language in solving a number of performance analysis problems in conventional multiprogrammed computers as well as distributed processing systems are described.     

系统性能极限理论的回顾和展望

描述了系统性能极限理论的研究对象、背景和意义,并简要介绍了系统性能极限理论所涉及到的四个相关问题,如:左可逆与右可逆系统、零点与零点方向、极点与极点方向以及灵敏度函数与互补灵敏度函数.同时,从H2型性能极限、频域及H∞型性能极限、时域及其他性能极限三方面综述了系统性能极限理论的研究现状,并对其未来的发展进行了展望.     

PHOEBE: an automation framework for the effective usage of diagnosis tools in the performance testing of clustered systems

The identification of performance issues and the diagnosis of their root causes are time‐consuming and complex tasks, especially in clustered environments. To simplify these tasks, researchers have been developing tools with built‐in expertise for practitioners. However, various limitations exist in these tools that prevent their efficient usage in the performance testing of clusters (e.g. the need of manually analysing huge volumes of distributed results). In a previous work, we introduced a policy‐based adaptive framework (PHOEBE) that automates the usage of diagnosis tools in the performance testing of clustered systems, in order to improve a tester's productivity, by decreasing the effort and expertise needed to effectively use such tools. This paper extends that work by broadening the set of policies available in PHOEBE, as well as by performing a comprehensive assessment of PHOEBE in terms of its benefits, costs and generality (with respect to the used diagnosis tool). The performed evaluation involved a set of experiments in assessing the different trade‐offs commonly experienced by a tester when using a performance diagnosis tool, as well as the time savings that PHOEBE can bring to the performance testing and analysis processes. Our results have shown that PHOEBE can drastically reduce the effort required by a tester to do performance testing and analysis in a cluster. PHOEBE also exhibited consistent behaviour (i.e. similar time‐savings and resource utilisations), when applied to a set of commonly used diagnosis tools, demonstrating its generality. Finally, PHOEBE proved to be capable of simplifying the configuration of a diagnosis tool. This was achieved by addressing the identified trade‐offs without the need for manual intervention from the tester. Copyright © 2017 John Wiley & Sons, Ltd.     

一种新的计算机抗攻击自身免疫模型

提出了一种新的计算机抗攻击自身免疫模型,形式化地阐述了模型如何使得不合法的程序和代码不能够执行,合法的程序和代码不能够执行未授权访问;合法的程序和代码的可疑行为受到严格的控制但是可以根据不同的阈值来保证实用性。这种模型不需要计算和识别计算机攻击的具体特征,而通过直接消除攻击能够实施破坏和传播的前提条件,使得计算机系统对攻击具备自身免疫能力。     

军用飞机预测与健康管理系统性能度量体系研究

基于健康退化曲线对军用飞机故障预测与健康管理( PHM)技术的内涵、基本功能和能力需求进行探讨,在此基础上,以科学评价PHM( prognostics and health management)系统的诊断和预测能力为目标,从能力需求出发提出PHM系统性能度量方法体系(包括诊断性能度量、预测性能度量以及综合度量),并对...     

面向对象冗余服务系统的性能分析与测试

通过对面向对象冗余服务系统的性能指标分析 ,结合实际应用中用户最为关心的性能价格比问题 ,利用数学分析模型 ,找出了满足冗余系统服务的最优解 ,并在此基础之上 ,对冗余系统的性能进行了分析与测试