面向用户态Click的I/O优化框架的设计与实现

软件路由器在现代网络的发展中发挥着越来越重要的作用,而Click是具有良好模块化设计的软件路由器,为开发和验证新的路由协议等应用提供了很好的软件平台。由于实现机制问题,用户态Click的I/O性能严重限制报文处理能力,影响以Click软件路由器为平台的系统的整体性能。针对现有Click用户态I/O机制的不足,提出了一种面向用户态Click的I/O优化框架,通过采用轮询技术、零拷贝技术和报文预取技术提升了I/O性能。实验结果表明:优化后的用户态Click的I/O性能提升了121倍。     

基于MINA框架的RTSP移动流媒体代理服务器设计与实现

该文设计了一个基于RTSP(Real Time Streaming Protocol)协议的移动流媒体代理服务器。基于该设计,作者在Apache MI-NA 2.0网络程序框架下实现了该代理服务器。该代理服务器可用于校园、酒店等公共热点环境,为具有WiFi功能的智能手机提供音视频接入服务。     

A Modular Approach to Mobile QoS Signaling— Motivation,Design & Implementation

In order to support mobile multimedia applications in next generation wireless IP-based networks, it is necessary to deliver seamless voice, video and data at high quality. Therefore, session mobility and Quality of Service (QoS) for mobile end systems are required. Within this article, the authors point out a new way to approach the problem. Instead of tightly coupling a modified QoS signaling mechanism with a certain mobility mechanism, a more generic and long-term solution is proposed and exemplified on the basis of existing IETF protocols. The connection-less IP network layer is enhanced by a lightweight and truly optional connection-oriented mobile network service, which offers the possibility to establish soft state unicast connections at the network layer. Hence, a connection-oriented network service is available within a radio access network (RAN) architecture to all end systems—mobile or fixed—independent of the application. Thereby, it is possible to integrate QoS and connectivity signaling for mobile end systems, as well as other connection-oriented services like explicit routing or load balancing.     

基于J2ME手机游戏设计及实现

基于J2ME技术开发了手机游戏"突围",首先通过游戏剧情及需求设计了游戏的功能流程,然后详细介绍了基于J2ME开发游戏的主类、主程序、背景类以及精灵类的设计及实现,最后介绍了关键技术敌机智能性的实现.     

一种生产型工作流管理系统的架构设计与实现机制

工作流管理是计算机支持协同工作（CSCW）中的一个重要领域，工作流管理系统（WfMS）是支持用户实现在需求不断变化的应用环境中流程处理的高效中间件．本文提出了由服务层、通信层和客户层三个层次构成的生产型工作流管理系统架构模型，描述了系统的核心服务，并通过一个基于J2EE平台的生产型工作流管理系统（Uniflow）实例描述其实现机制．     

一种多源统一爬虫框架的设计与实现

面向深层网数据的爬虫技术与反爬虫技术之间的对抗随着网站技术、大数据、异步传输等技术的发展而呈现此消彼长的趋势。综合对比当前主流的爬虫和反爬虫技术,针对高效开发、快速爬取的需求,MUCrawler(多源统一爬虫框架)被设计成一种可以面向多个网站数据源,以统一的接口形式提供爬虫开发的Python框架。测试结果显示,该框架不但能够突破不同的反爬虫技术获取网站数据,在开发效率、鲁棒性和爬取效率等方面也体现出较好的运行效果。     

校园移动门户设计与实现

校园移动门户是当前各大高校数字化校园的重要发展战略之一,是对传统教育及管理方式的有益补充。笔者首先介绍了校园移动门户的总体设计目标,其次介绍了服务端、终端自存储、移动应用管理平台三部分的设计,最后详细介绍了应用中心。广大师生在智能移动终端上可随时随地查询、发布信息,提高了工作和学习效率,加强了学生、教师、学校、社会之间的沟通。     

The Design and Implementation of a Mobile Learning Resource

The convergence of mobile communications and handheld computers offers the opportunity to develop technology that will assist individuals and groups to learn anytime, anywhere. We describe the theory-informed design, implementation and evaluation of a handheld learning device. It is intended to support children to capture everyday events such as images, notes and sounds, to relate them to web-based learning resources, to organise these into a visual knowledge map, and to share them with other learners and teachers. A working prototype system, for children aged 9–11, is discussed and evaluated, as an exemplar of personal mobile systems for life-long learning.     

移动应用转换的非侵入式架构的设计实现

随着移动互联网技术的发展．越来越多Web应用开始向移动应用转换。为了降低系统开发工作量和集成难度,提出移动客户端接入Web应用的非侵入式架构的设计与实现方式,通过实践验证,可以有效、快速地对Web应用进行转换。     

移动分组无线网多播协议的设计与实现

提出了用于移动分组无线网的多播路由协议。在移动分组无线网环境中,多播路由协议起着非常重要的作用。传统的应用于有线网络的多播方法无法适应移动分组无线网具有的拓扑结构变化和带宽有限等特点。在协议中不需要维护全局的路由信息,而采用按需路由发现策略,动态建立路由信息及维持多播组成员关系。仿真实验显示协议在带宽较低、多播组成员数量变化较大的移动分组无线网环境中,具有较好的可靠性和工作效率。     

Design and Implementation of a PKI-Based End-to-End Secure Infrastructure for Mobile E-Commerce

The popularity of handheld mobile devices and deployment of the public key infrastructure in many parts of the world have led to the development of electronic commerce on mobile devices. For the current version of mobile phones, the main challenge is the limited computing capacity on these devices for PKI-based end-to-end secure transactions. This paper presents a new architecture and protocol for authentication and key exchange as well as the supporting infrastructure that is suitable for the mobile phone environment. The system requirements and our solutions in addressing these requirements in the restrictive environment are discussed. An evaluation of the system performance is also included. The system has been implemented and is supporting some real-life applications.     

Design and Implementation of Fuzzy Parallel-Parking Control for a Car-Type Mobile Robot

The theme of this paper is to design and implement a car-type mobile robot (CTMR) that possesses autonomous parallel-parking capability. At first, we introduce the hardware architecture of the CTMR, which consists the robot mechanism, microcomputer part, electronic driver, and sensor. Two fuzzy parallel-parking controls (FPPC), the backward and forward parallel parking, are provided to maneuver the steering angle of the CTMR. Computer simulations are used to illustrate the effectiveness of the developed FPPC schemes. For real-time implementations, we utilize two FPPC methods that we proposed in simulation to back-drive or head-in the CTMR to the parking lot. Both simulation results and real-time experiments demonstrate the feasibility and effectiveness of the proposed intelligent parallel-parking control system.     

面向多终端适配的移动中间件的设计与实现

随着3G技术的应用和推广,手机游戏、动漫、音频、视频等应用成为手机增值业务的重要发展方向.而现有的手机应用普遍存在两方面的问题:一是应用的开发比较复杂,需要面对不同的应用逻辑;二是手机应用需要支持各种不同的手机终端,适配工作量巨大.因此,本文在传统中间件、移动中间件思想的基础上,提出一种面向多终端适配的移动中间件的架构...     

移动互联网监控仪的设计与实现

移动互联网监控仪由嵌入式硬件和监控软件两部分组成,嵌入式硬件由CPU、Flash存储器、以太网接口卡、无线网卡组成,监控软件由基于Linux内核的主程序和分析程序组成,主程序捕捉经过网络终端传输的数据包,分析程序把过滤所得的数据包发送给后台服务器存储。在移动互联网中进行数据链路层监控,用户自定义需要监控的关键字,对数据进行关键字和主题领域的列表进行字符匹配,对敏感信息数据包或者不和谐内容的数据包进行监控并存储。     

A Framework for Cache Management for Mobile Databases: Design and Evaluation

In a mobile computing environment, database servers disseminate information to multiple mobile clients via wireless channels. Due to the low bandwidth and low reliability of wireless channels, it is important for a mobile client to cache its frequently accessed database items into its local storage. This improves performance of database queries and improves availability of database items for query processing during disconnection. In this paper, we investigate issues on caching granularity, coherence strategy, and replacement policy of caching mechanisms for a mobile environment utilizing point-to-point communication paradigm.We first illustrate that page-based caching is not suitable in the mobile context due to the lack of locality among database items. We propose three different levels of caching granularity: attribute caching, object caching, and hybrid caching, a hybrid approach of attribute and object caching. Next, we show that existing coherence strategies are inappropriate due to frequent disconnection in a mobile environment, and propose a cache coherence strategy, based on the update patterns of database items. Via a detail simulation model, we examine the performance of various levels of caching granularity with our cache coherence strategy. We observe, in general, that hybrid caching could achieve a better performance. Finally, we propose several cache replacement policies that can adapt to the access patterns of database items. For each given caching granularity, we discover that our replacement policies outperform conventional ones in most situations.     

BACnet软网关应用框架的设计与实现

楼宇网络中,经常遇到楼控设备使用私有协议的情况,为了使其能访问BACnet网络和方便BACnet工作站控制,通常的解决方法是开发BACnet软网关做协议转换。开发BACnet软网关的过程有很多工作是很繁琐重复的。本文提出了一种BACnet软网关应用框架的实现方案,通过封装BACnet协议和利用VC的应用程序框架,使windows平台上BACnet软网关开发过程得到简化和加速。     

The Design and Implementation of a Framework for Automatic Modularization of Software Systems

It is a difficult task to manually cluster a large software system into loosely coupled modules with a large number of highly cohesive classes. On the other hand clustering is a NP-Hard problem. In this paper the design and implementation of a flexible software environment, called DAGC, to assemble and experiment with genetic clustering algorithms, for software (re)modularization, is described. The main idea behind the design of the DAGC is to define a general genetic clustering algorithm which may invoke different implementations for the parts from an extendable list of components. The DAGC provides visualization facilities to compare and evaluate different genetic clustering algorithms, regarding the two parameters of running time and the quality of clusters generated by the algorithms.     

邦元框架生成工具的设计与实现

邦元框架生成工具是用来自动生成邦元模型的框架程序.针对目前邦元程序开发与仿真应用结合过于紧密,通用性不足,在进行邦元框架生成工具总体结构设计的基础上,实现了一个仿真应用框架程序的自动生成工具.该工具具有支持邦元基本流程的框架生成、解读FED文件、自动生成基于Windows程序的邦元框架、邦元框架与Windows多框架的结合等功能.支持对象模型和实体模型两个层次的导入,能够在Visual Studio开发环境下根据使用者的要求自动生成仿真应用的程序模板,大大提高了工作效率,并保证了仿真应用实现的正确性.