采用启发式算法的无线自组网网络编码方法

首先证明了与应用网络编码相关的最优化问题是NP完全的,然后提出了一种采用启发式算法的网络编码方法COMP。该网络编码方法利用贪婪集合配置启发式算法和贪婪集合覆盖启发式算法的基本思想来尽可能多地挖掘网络编码机会。NS-2仿真结果表明,该网络编码方法在应用到节点数比较多、最大传输范围比较小以及会话数比较多的场景中时,有效地减轻了并发会话的影响,提高了现有广播算法的性能,而且其性能提高超过了现有的网络编码方法。     

基于组件的算法测试系统的建模与实现

为构建一个通用的信息融合算法测试系统,采用组件技术,定义通用的接口规范,使得在不同平台不同环境下开发的算法在符合接口规范的条件下,完全与系统兼容.在后期的算法的维护和改进过程中,接口不变的情况下只对内部处理进行修改,就能够实现算法的再测试,形成一个有利于算法开发与研究的辅助平台.     

多穴嵌套网络移动的快速切换算法

链路容错是多穴嵌套移动网络的一个重要议题.在分析多穴嵌套移动网络存在的问题和回顾现有链路容错方案基础上,提出接入路由器树模型及其三类快速切换算法以确保当前会话在接入链路失效突发时的连续性.算法具有以下优点:(1)切换延时降低;(2)数据包利用率加大;(3)兼容原有网络移动协议,易于实现.算法的仿真结果表明,和现有的方案相比,本文算法的切换延时和相应的数据传输延时最小,可以实现链路容错.     

基于MDE的AADL构件组合兼容的方法

实时嵌入式系统建模语言—体系结构分析与设计语言AADL是一种基于组件的半形式化建模语言,当AADL构件模型进行组合时,因为一些交互活动的序列不匹配从而导致构件组合行为不兼容,提出了一种基于模型驱动方法 MDE的AADL构件组合兼容方法。利用MDE异构模型转换框架将AADL模型转换至接口自动机IA,利用形式化方法验证IA的兼容性,使用IA Tool构建IA模型的构件兼容运行环境,将构造的环境映射到AADL组件,能够解决AADL构件组合的行为兼容性问题。     

面向会话的负载均衡简化算法

负载均衡算法被广泛应用于并行处理、服务集群等环境中．一些基于网络报文内容相关性的应用。例如IDS和IPv6的Anycast服务等要求在对报文进行负载均衡分配时要保持网络会话的相关性。即相关的报文要分配到同一个处理节点．否则其语义不能得到正确处理．传统的负载均衡算法对于这类服务需要在会话的上下文信息规模和会话完整度之间权衡，对于会话数量很大的情况通常开销也很大．基于位熵的概念，本文提出了一种可满足会话完整性的负载均衡简化算法一域分类算法．该算法不需要各处理机之间内部通信协调工作．也不需要在调度节点保持会话的上下文。在满足报文或会话相关性要求的同时．仍能保持较好的宏观平衡度和微观平衡度．     

基于鉴权矢量相似度分析的GSM鉴权改进算法

现有GSM无线通信系统中应用最为广泛的是COMP128-1算法,其安全漏洞最早是由伯克利大学的一个研究小组公布的。本文主要分析了现有的针对COMP128-1算法漏洞的一些攻击及防护手段,提出了基于相邻鉴权矢量的相似度分析的新的安全防护手段,以有效识别对COMP128-1漏洞的攻击鉴权行为,从而有效抵抗这些攻击手段,保护KI不被破解。     

普及计算中基于接口语义描述的动态服务组合方法

在普及计算环境中缺乏把已经存在的简单的服务灵活地动态地组合出更加复杂的服务的方法．提出了一种在此环境下的基于接口语义匹配的动态服务组合方法，给出了基于语义的基本服务的描述规范、组合服务的描述规范、组合服务的实例生成算法和控制执行的动态服务组合的系统框架并通过实例实现，验证了该框架的可行性．根据当前环境中已有的服务组合出更加复杂的服务，该算法对有效地利用系统的资源、降低服务设计和实现的复杂性具有非常重要的意义．     

GSRP--一种支持连接恢复和会话移动的消息传输协议

从网格用户环境等场景和移动网络特点出发,归纳出网络协议中持久性、全局性、松耦合、内容和传输分离的原则,并提出支持连接恢复和会话移动的网格服务请求协议(GSRP)．GSRP采用松耦合的应用会话层和消息传输层两层结构,分别负责消息内容及应用之间消息交互和消息封包及传输．全局性的持久会话句柄为不同主机和不同应用之间实现网络会话的协同和移动提供了开发接口,软连接在持久会话句柄和底层网络链路之间建立映射,完成消息的传输．单边操作和延迟容忍技术被用在数据通信和状态管理中,简化了应用开发和维护．给出GSRP的设计和实现,结果表明GSRP在没有增加大的额外开销的同时,获得了休眠、移动和对底层网络的适应能力,可以满足所关心的新应用的需求．     

基于接口连接关系的服务组合启发式算法

针对服务组合规划问题,提出了一种基于服务连接关系的启发式算法.该算法首先根据领域本体中概念条件出现概率提出了一种新的服务接口分量关联程度量化指标,再利用二分图稳定匹配算法解决了多输入输出分量接口匹配问题,在此基础上将服务组合规划抽象为与或图搜索,采用启发式算法实现了服务组合.实验结果表明,该算法能够根据用户请求动态的生成复合服务,通过服务连接分析预处理,可以有效解决输入输出接口多分量的服务连接问题,提高了服务组合效率.     

基于压缩感知的人脸识别方法

基于稀疏重构的分类方法具有较好的识别效果,但计算复杂度高。为此,提出基于压缩感知的人脸识别方法COMP,将L1范数最小化重构算法替换成正交匹配追踪(OMP)算法,以降低复杂度,并在OMP中引入模式类别信息,使该方法具有更强的分类能力。基于YaleB人脸库的实验结果表明,COMP在低维度时识别率高于OMP。     

网络并行计算系统的消息存储器网络接口设计

文中通过定性分析典型并行应用程序,提出产蒙义了消息传递无关因子Ｒ,即堆中的数据的传递在整个消息传递中所占比例,而且后在一个实际的ＮＰＣ环境中对一组典型并行应用程序进行踪迹统计,证实了Ｒ接近１的分析,根据这个定性分析以及定量统计结构,结合存储器技术的进展,在ＮＰＣ中的网络接口上引入了消息存储器,使得ＮＰＣ中各个结点可以直接访问其它结点的消息存储器,通过竣是出结论,在设置了消息存储器的网络接口的ＮＰＣ     

A blocking model for reactive objects

Objects can be viewed as entities reacting concurrently with their environment through the sending and receiving of messages. In this paper a model for such reactive objects is constructed where messages may be blocked either by the object or by the environment. This model differentiates between output messages controlled by the object, and input messages controlled by the environment. The model is applied to define an object compatibility lattice structure enabling the construction of objects satisfying best possible compatibility requirements.     

ILAN Intelligent Local Area Network Planning Software

The objective of this research is to develop an analysis tool for evaluating a token bus topology, supporting the Manufacturing Automation Protocol (MAP). Furthermore this research describes an easy-to-use graphical interface for a complex simulation program. Specifically, a graphical user interface for MAP network simulation program is illustrated. Simulation of MAP sub-networks interconnected by bridges can be performed without further programming. This software, called ILAN, features a unique graphical user interface with message definition facility and an error-checking inference engine which advises users of any instances of duplicated or omitted information. ILAN's problem-definition phase is simplified by implementing a single graphical user interface for all inputs.

Two main procedures within ILAN consist of a local area network simulation and an intelligent graphical interface with a unique graphical message definition facility. The simulation procedure includes the ability to model different numbers of multiple MAP sub-networks interconnected by bridges and different numbers of associations between stations using the token bus protocol. Higher layers in the protocol stacks are modeled as queues having variable delays for different messages at different stations. In order to aid users with the difficulty of inputting parameters needed to simulate complex MAP networks, a graphical user interface is developed. By means of this graphical interface, users can describe the MAP hardware configurations as well as message definitions to be simulated. Sequences of messages to be transmitted can be displayed on the screen as users describe them.     

Portable and Scalable Algorithm for Irregular All-to-All Communication

In irregular all-to-all communication, messages are exchanged between every pair of processors. The message sizes vary from processor to processor and are known only at run time. This is a fundamental communication primitive in parallelizing irregularly structured scientific computations. Our algorithm reduces the total number of message start-ups. It also reduces node contention by smoothing out the lengths of the messages communicated. As compared to the earlier approaches, our algorithm provides deterministic performance and also reduces the buffer space at the nodes during message passing. The performance of the algorithm is characterised using a simple communication model of high-performance computing (HPC) platforms. We show the implementation on T3D and SP2 using C and the message passing interface standard. These can be easily ported to other HPC platforms. The results show the effectiveness of the proposed technique as well as the interplay among the machine size, the variance in message length, and the network interface.     

基于XML描述的动态可扩展数据报文的模型构建方法

通过分析航空、通信、航天等领域综合电子项目中常规总线数据报文,以及动态可扩展数据报文,归纳出数据报文结构特点,研究了适应动态可扩展数据报文的描述模型,并给出基于XML语言对动态可扩展数据报文模型的实现方法。通过该方法解决了动态可扩展数据报文难以统一描述问题,可实现软件代码与接口定义的解耦;解决了因接口变更导致修改软件代码的问题,可提高软件代码的通用性和适应性。该方法设计的总线接口测试软件已在多个型号工程的中应用,可达到在不修改软件代码的情况下,配置多种类型的常规数据报文或动态可扩展数据报文进行数据总线通信。     

Network Performance Under Bimodal Traffic Loads

In actual multicomputer networks, communications consist of hybrid traffic in which messages exhibit a variety of sizes. However, to date, most studies on network performance are based on traffic loads of uniformly-sized messages. We investigate the performance of wormhole-routed networks under bimodal traffic distributions, a mix of short and long messages. Our studies show that the presence of long messages degrades network performance for short messages dramatically, qualitatively changing network behavior. We present an analytical model for wormhole-routed networks which not only models network performance under uniformly sized message loads more accurately than existing models, but also can be extended to support bimodal traffic distributions. The model is validated against detailed simulation of routing networks, over a variety of message size distributions and message lengths. In virtually all cases, the model accurately predicts both network throughput and average message latency to within 8%. Because the impact of long messages can be severe, we consider three techniques-packetization, virtual lanes, and adaptive routing-to alleviate their impact. Packetization reduces the blocking time of long messages, improving network performance in most cases. Virtual lanes and adaptive routing together provide sufficient routing freedom to eliminate much of the blocking, producing performance comparable or even superior to that produced by packetization. Together, all three techniques are complementary, providing robust performance over a variety of traffic mixes and message sizes.     

Hierarchical message bus-based software architectural style

As the size and complexity of software systems increase, the design and specification of overall system structure become more significant issues than the choice of algorithms and data structures of computation. An appropriate architecture for a system is a key element of its success. Based on the practice of Jadebird software production line, this paper proposes a software architectural style based on hierarchical message buses, named JB/HMB. In this style, the component model consists of external interfaces, static structure and dynamic behavior, which depicts a component from different aspects. Supported by message buses, components interact with one another by messages, which can be used to describe distributed and concurrent systems well. JB/HMB style supports stepwise decomposition and refinement, and runtime system evolution. Finally, characteristics of JB/HMB style are summarized as a conclusion, and future research directions are specified.     

面向Web的JMS应用系统

JMS面向Web的应用与面向桌面的应用相比,有特殊的用户环境要求：同一个消息必须能被若干未知的用户消费,因此在消息接收方必须有“接收而不确认”的提交机制。本文以CwNF校务系统为实现案例,讨论面向Web的JMS应用系统消息提交原理及采用的关键技术。     

多智能体系统中信使功能的设计和实现

针对多智能体系集成开发环境需要实现智能体之间消息的透明传送，从而智能体开发者可以集中于智能体应用逻辑开发的目的，研究了负责智能体之间的通信以及实现智能体通信时同步的信使的主要功能，主要介绍了智能体对应信使间的链接方法，消息发达和接受技术，以及记录智能体之间通信消息的信箱的管理技术，并给出了设计实现的智能体通信应用程序接口函数的内容。