VPN 系统反馈调整和实时监控集成解决方案

传统VPN系统存在不能根据状态自动调整运行,而且缺乏对运行状态的监控的问题,为此以Open VPN为基础,提出一个VPN系统自动管理和实时监控解决方案,通过编写程序分析和理解服务运行状态,根据反馈触发执行相应管理程序,与管理端口进行通信调整服务行为,同时使用SNMP协议构造监控代理程序,对系统性能进行实时监控,使得管理员能够通过Cacti监控平台实时了解系统运行参数,达到保障VPN服务持续可靠和高效运行的目的。实验结果表明,该系统能够根据当前状态所设定的规则优化运行,并为管理员提供直观实时的性能视图。     

基于RTX的分布式平台级仿真系统设计与实现

研究平台级仿真训练系统,广泛应用于武器装备试验评估领域中,平台级仿真包含实体数多、交互信息复杂.如果有人或硬件在回路,则需实现实时运行.如果采用分布式结构,还需实现时钟同步.为了解决实体间复杂信息交互、强实时运行和时钟同步控制等问题,提出参照HLA的数据交互机制和时间推进机制设计了平台级仿真系统框架,并采用流行的Win-dows+RTX平台开发了仿真系统软件.经时间测试,设计的仿真系统满足微秒级的定时精度和死线(dead-line)要求.仿真表明,设计方法适用于平台级、多仿真实体交互,为强实时推进的分布式实时仿真系统构建提供了参考.     

基于铁电体存储器的门禁系统

非易失存储器和实时时钟是门禁系统必备的单元。本文介绍了一种基于铁电体存储器FM31256的门禁系统。FM31256是一种采用铁电体技术的多功能串行存储器芯片。除了非易失存储器外，该芯片还具有实时时钟，电源检测，看门狗，事件计数器，可锁死的64位码存储和比较器等多种功能，具有读写速度快、擦写次数无限、可靠性高等特点，十分适合在门禁系统中使用。文中讨论了基于铁电体存储器的门禁系统具体实现方法，并给出了系统原理框图和软件流程图。     

6522VIA在两级微机控制系统中的应用

叙述了采用6522ⅥA构成两级微机控制系统实时时钟和实现上下位机定时并行通讯的硬件构成、软件设计与工作过程。该方法硬件开销省,软件运行可靠,时钟、通讯、控制与系统监控管理相互配合协调。     

科技文摘信息

用于实时多任务调度的软件时钟 DOS环境下进行实时多任务软件设计,为了使CPU对各任务有一个合理的时间分配,希望根据各任务对响应时间的要求,使不同的任务在不同周期时钟调度下运行。为此,作者研制了一个用于实时多任务调度的软件时钟平台,它能产生周期为1～55ms的时钟中断,不同响应时间的任务可以在它的调度下运行。作者提供了程序清单。 武汉华中理工大学塑性研究所(430074)     

基于Freeradius的VPNWeb管理平台的实现

通过分析VPN管理平台软件的现状,进一步作系统可行性分析,并对系统进行总体设计、整体架构设计,从而构建了一套WEB管理平台,主要实现公告管理、用户管理、服务器管理、账单管理四大核心功能,利于管理员对VPN用户进行流量、时长等的管理以及VPN系统的整体管理与运作。     

经编机远程监控系统的数据采集与处理

针对现代工业监控的地理位置分散、布线成本高,对数据实时性要求较高的问题,结合3G网络和传统工业监控终端设备,提出了一套经编机监控系统解决方案,通过VPN虚拟专网实现现场设备与中心服务器之间的无线通讯,能够实时远程获取经编机的工况、运行数据以及故障诊断等功能。详细介绍了监控系统软件如何通过3G网络进行数据采集与处理的设计与实现过程。实验结果表明:实时数据采集正常,系统运行状态良好,为现代传统工业实现网络化管理,具有一定的应用推广价值。     

双机时钟不同步情况下虚拟示波器波形显示方法的改进

风电变流器虚拟示波器软件主要用于对变流器系统参数的实时监测,软件基于CAN通讯方式,利用MFC开发平台编程实现,可与单台变流器(单机)或两台变流器(双机)建立连接并启动实时监测。双机情况下,受变流器控制器时钟不同步的影响,两变流器发送的数据总量不一致,导致软件接收的数据总数不一致,从而对波形的显示效果产生影响。针对双机情况下波形显示问题进行了分析,通过扩大接收缓冲区容量的手段,对双机的波形显示方法进行了改进。通过双机连接测试,虚拟示波器软件界面显示正常,可以实现长时间的稳定运行。     

基于Keil C51的软件看门狗系统设计

介绍了一种基于Keil C51环境的软件看门狗设计方法.通过设置程序、喂狗程序和中断服务程序的有效配合,解决软件模块的稳定性问题.设置程序在模块开始处对看门狗系统进行初值设定,喂狗程序在模块结束时进行参数设置.通过T0中断服务程序监视软件模块的运行,T1中断服务程序监视T0定时器的运行,设置程序监视T0和T1的运行,以达到看门狗系统的循环监视.此设计方法可以提高程序模块的稳定性,特别是对于顺序控制结构的软件尤为适用.     

基于FPGA的微处理器内核设计与实现

设计了基于FPGA并与MCS-51单片机指令兼容的高效微处理器内核。本内核改进了传统MCS-51单片机的体系结构,使每个机器周期只需一个时钟周期,提高了指令的执行效率。同时增加了硬件看门狗及软件复位功能,提高了系统的可靠性和抗干扰能力。本内核通过了功能仿真并下载到FPGA中成功运行。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.