门禁系统中通信平台的应用

传统门禁控制系统并不支持出入口控制器系统的网络化,本文通过引入通信平台,给出了一种实现TCP/IP的新方法,通信平台在操作软件客户端和控制器之间架起了TCP通道,通过对串口数据和客户端TCP/IP数据包进行转换可以任意客户端访问网络节点上的硬件服务器,实现TCP/IP通信,减少系统施工布线.     

一种异地库房管理中远程数据维护方法的研究与应用

介绍了在异地库房管理中，采用C／S结构和远程数据库访问技术等实现的对远程数据维护的一种方法。通过该方法开发的远程数据传输系统，实现了远程客户端对服务器的通信，完成了远程数据在后台服务器的集中管理和服务器对远程数据的格式、类型等的控制，同时保证了远程客户端对服务器操作的并发性，客户端数据和服务器数据的完整性、安全性以及远程客户端数据与后台服务器数据的一致性，有效地维护了远程数据。该系统已成功运用于库房管理之中。     

基于ARM的智能网络家居系统的设计与实现

应用S3C2440处理器构建了智能网络家居系统,在Linux操作系统下构建了BOA服务器,具有源代码开放、性能高等特点,利用HTML语言和CGI构建Web客户端,通过TCP/IP协议实现了客户端和服务器端访问,实现远程控制和数据采集。     

采用混合架构的指挥控制系统的研究与实现

指挥控制系统是国防信息化建设的一个重要方向.本文提出了C/S和B/S混合架构,对于安全性和实时性要求比较高的部分采用C/S,其他部分采用B/S.在此基础上,通过数据访问层将系统实现与业务逻辑分离,使数据库对用户完全透明.通过运行代理RunProxy来连接客户端与服务器,使服务器IP对外不可见,提高了服务器的安全性,并使服务器可以支持更多的客户端连接,同时对数据在RunProxy中进行了过滤.     

制作设备IC卡管理系统改进方案

我台采用的制作设备IC卡管理系统（详见《电视字幕·特技与动画》2005年8期）以SQL SERVER2000数据库服务器为核心,以管理计算机和各机房分控计算机为远程客户端,系统软件设计采用C／S结构,应用ADO编程模型实现对数据库服务器的访问;各分控计算机子系统安装相应的客户端软件,定时与数据库服务器通讯更新数据信息,通过串口下连IC卡读卡器,在各机房的分控计算机内部安装了基于PCI总线的I／O通道控制卡PCI-1751．该卡内有82C55等效电路,通过控制82C55的各位输出．实现对电源控制箱的控制。     

分布式虚拟化电子元器件测试系统开发与设计

通过对WebSocket技术和uIP TCP/IP栈的研究，提出了一种基于B/S和C/S混合结构的分布式虚拟化测试平台模型。该平台采用WebSocket中间件服务器技术，运用HTML 5中的WebSocket协议进行数据分发，利用uIP TCP/IP栈实现远程智能网关，应用虚拟化技术在Web页内嵌入仪器操作控制面板，通过WebSocket技术实现数据的实时传输。用户可以通过浏览器向Web服务器提交命令和参数，远程控制仪器设备，实时观察测试结果。     

IP Trap的实现与应用研究

IP Trap是用来截获TCP/IP层数据信息的软件,可以把连接发起端和终端的数据信息无修改地保存下来供管理者分析。通过对IP Trap技术及网络互联协议的学习、总结和研究,采用套接字编程,设计出自己的IP Trap软件。软件采用客户/服务器（C/S）模式,实现了IP地址的动态捕获,使服务器端能准确地截获并保存客户端的相关数据,增强网络安全分析的可实施性。     

应用于物联网的Linux云端服务器设计

为实现物联网网络层中对数据的高效处理与管理,基于TCP/IP协议提出Linux平台的云端服务器。用于处理由网关通过Internet上传至服务器的数据,可实现多客户端的数据上传与反馈,采用并发的TCP连接机制处理网关与服务器的通信接口,服务器内部模块采用UDP通信方案。     

基于Maemo系统拍照上传服务器

本文介绍了多线程文件传输模型,给出多线程多客户与服务器（C／S）并发通信模型的详细算法,并介绍了基于Maemo系统利用socket进行TCP网络连接、并通过多线程技术,实现了拍照上传服务器的应用,最后展示客户端成功将拍摄的照片上传到服务器的演示效果。     

基于以太网的远程数据采集系统设计

针对远程数据采集方面的应用需求,设计了一种基于ARM微处理器的以太网数据采集系统。选取S3C2440作为数据处理器和控制器,DM9000作为网络芯片,在Linux为操作平台下,实现了10位数据采集,并将采集到的数据经过S3C2440的处理,通过以太网传输到服务器上。数据传输采用的网络通信协议是TCP/IP协议,通信过程采用C/S模式。     

面向资源有限设备的DDS通信中间件设计

DDS拥有良好的实时性、拓展性和数据处理能力,适合分布式场景中大数据量和多样化的通信需求。针对标准DDS通信中间件过于复杂、庞大,不适合在资源有限的嵌入式设备上部署的问题,文中在对DDS规范进行了深入分析研究后,对DDS功能进行了裁剪、优化,提出了一种基于卡尔曼滤波模型的对称式发布订阅机制,减少了通信中的冗余数据,并使用C语言实现了一种轻量化且具有可移植性的DDS通信中间件。文中在ARM+X86平台上对该通信中间件进行了测试验证,结果证明该中间件能够在占用少量资源的情况下,为应用提供基本的DDS服务,提升了系统的响应速度,节约了通信带宽资源。     

科学数据网格中数据访问中间件的研究

基于Globus的网格技术提供了数据访问的统一服务接口,但它本质上还是Client/Server模型,在发布和发现服务上采用集中式模式,所以可扩展性差,而且对海量数据访问比较低效.为此结合P2P一些特性,提出了一种数据访问中间件框架,具有可扩展性、数据访问高效性等特点,并实现了基于它的数据查询功能.     

基于CORBA的多代理B/S系统的设计

CORBA是对象管理组织的分布式对象中间件应用标准，而Java是实现客户和服务器CORBA的理想语言。文章讨论了CORBA防火墙规范和Java沙箱安全机制，提出使用多代理技术以实现基于CORBA的分布式对象Web，从而构架出多层B／S系统。     

Android异常入侵检测中的主动响应系统

手机恶意程序有对智能手机用户造成经济损失、数据丢失及隐私泄露等危害。在现有的Android入侵检测系统框架基础上,提出异常入侵检测中的主动响应系统,及时减轻手机恶意软件对用户造成的危害。该主动响应系统采用C/S架构,其中客户端收集手机中应用的程序信息,负责最后的响应措施;服务器端及时静态分析由客户端发来的可执行文件,锁定导致手机出现异常状态的恶意程序。测试结果表明,该系统可以主动对手机上已发现的异常行为做出及时有效响应。     

基于J2EE的三层体系结构在社保系统中的应用

主要介绍了基于J2EE的B／S三层结构在新疆社保信息系统中的应用，将C／S体系结构中原本运行于客户端的应用程序移到了中间层，由中间件服务器进行相应的业务处理，实现了客户端的零维护，提升了应用系统的适应能力。     

Smart Cities via Data Aggregation

Cities have an ever increasing wealth of sensing capabilities, recently including also internet of things (IoT) systems. However, to fully exploit such sensing capabilities with the aim of offering effective city-sensing-driven applications still presents certain obstacles. Indeed, at present, the main limitation in this respect consists of the vast majority of data sources being served on a “best effort” basis. To overcome this limitation, we propose a “resilient and adaptive IoT and social sensing platform”. Resilience guarantees the accurate, timely and dependable delivery of the complete/related data required by smart-city applications, while adaptability is introduced to ensure optimal handling of the changing requirements during application provision. The associated middleware consists of two main sets of functionalities: (a) formulation of sensing requests: selection and discovery of the appropriate data sources; and (b) establishment and control of the necessary resources (e.g., smart objects, networks, computing/storage points) on the delivery path from sensing devices to the requesting applications. The middleware has the intrinsic feature of producing sensing information at a certain level of detail (geographical scope/timeliness/accuracy/completeness/dependability) as requested by the applications in a given domain. The middleware is assessed and validated at a proof-of-concept level through innovative, dependable and real-time applications expected to be highly reproducible across different cities.     

Research Issues in High-throughput Distributed Object Systems

It is an unfortunate fact that current general-purpose middleware implementations cannot support large-scale, wide-area, real-time, high-throughput applications using distributed objects. This paper discusses the background to middleware and explores the need for research into techniques that support high-capacity implementationsIn order to place the role of this work in context, an overview is given of the simple applications-middleware-infrastructure three-layered model that has been adopted. The paper also gives some background on how applications may specify the non-functional characteristics that they demand of supporting middleware, including invocation latency, which is a widely recognised, measured and reported metric, and invocation throughput rate, which is not.The paper establishes that there is a growing demand for high-invocation-throughput applications, such as the World Wide Web (WWW), collaborative virtual reality (CVR) and intelligent networks (INs), and also that there is increasing availability of suitable high-capacity infrastructure including networks, hosts and operating systems. It also examines the reasons for a lack of implemented high-capacity capacity middleware and reviews current directions in distributed object (DO) research. There is insufficient but growing activity in high-throughput techniques, such as weak-consistency approaches to object replication, that would enable applications to take advantage of high-capacity infrastructure.     

Linux下基于TCP的预先派生子进程服务器的Socket编程

描述了客户/服务器模型以及常见的服务器类型——基于TCP的并发服务器。在一个基于TCP回射服务器程序的基础上,结合实际Web应用中的多进程服务器模型,考虑到原有的客户/服务器交互存在的问题,改进了客户程序,设计了实现并发功能的客户程序、并发服务器以及预先派生子进程服务器。在装有Linux的PC上分别进行客户程序和服务器程序的测试。实验结果表明:在与并发客户的TCP交互中,与并发服务器相比,预先派生子进程服务器能够及时处理新的客户连接,且响应时间减小到并发服务器的三分之一,达到了对服务器性能优化的目的。     

Techniques for enhancing real-time CORBA quality of service

End-to-end predictability of remote operations is essential for many fixed-priority distributed real-time and embedded (DRE) applications, such as command and control systems, manufacturing process control systems, large-scale distributed interactive simulations, and testbeam data acquisition systems. To enhance predictability, the Real-time CORBA specification defines standard middleware features that allow applications to allocate, schedule, and control key CPU, memory, and networking resources necessary to ensure end-to-end quality of service support. This paper provides two contributions to the study of Real-time CORBA middleware for DRE applications. First, we identify potential problems with ensuring predictable behavior in conventional middleware by examining the end-to-end critical code path of a remote invocation and identifying sources of unbounded priority inversions. Experimental results then illustrate how the problems we identify can yield unpredictable behavior in conventional middleware platforms. Second, we present design techniques for ensuring real-time quality of service in middleware. We show how middleware can be redesigned to use nonmultiplexed resources to eliminate sources of unbounded priority inversion. The empirical results in this paper are conducted using TAO, which is widely used and open-source DRE middleware compliant with the Real-time CORBA specification.     

Disconnected Processes, Mechanisms and Architecture for Mobile E-Business

With the tremendous advances in hand-held computing and communication capabilities, rapid proliferation of mobile devices, and decreasing device costs, we are seeing a growth in mobile e-business in various consumer and business markets. In this paper, we present a novel architecture and framework for end-to-end mobile e-business applications (e.g., point of sales). The architecture takes into consideration disconnection, application context, synchronization, transactions and failure recovery modes to provide mobile users with seamless and transparent access to business transactions and business-context specific data. In our architecture, we consider a novel business process design based on state-machines and event management to handle disconnection, resource limitations and failures. We designed, implemented and deployed a system for mobile e-business on clients (e.g., PDAs and PocketPCs) integrated with private exchanges and sell-side servers. The state-machine model with failure recovery mechanisms enables handling of one-to-many and many-to-one disconnections in large mobile e-business environments. The e-business framework on mobile clients is implemented based on J2ME, Webservices, and open XML standards. A detailed performance study of commerce transactions was done on different mobile client devices with diverse computing, memory and storage capabilities. We compare the performance of a purchasing application and the middleware on various devices such as PDAs and Laptops. We demonstrated that for small devices with limited capability the performance is reasonable. For devices with more computing capability, the response time is excellent.