安全审计在电子政务中的应用

在分析当前电子政务所面临的安全挑战的同时,提出了安全审计的概念,并提出了应该在电子政务中增加安全审计功能的这一思想。并且在文章的最后,还给出了在构建带有安全审计的电子政务系统时,应该考虑和注意的几点问题。     

Reflections on Trust in Devices: An Informal Survey of Human Trust in an Internet-of-Things Context

Trust is an essential component of every interaction we make. For some transactions we need very little trust, while for others we may be quite risk averse. In this paper we investigate trust in an Internet-of-Things environment. Can we trust devices? How can we quantify trust in devices?     

HDTV图像清晰度复合测试图

本文设计、生成了HDTV图像清晰度复合测试图。按在极坐标系建立的数学模型，由计算机逐象素编程计算、生成的该测试图，精度高，便于修改，已在定量测定数字图像清晰度中得到应用。     

基于定向天线的移动自组网技术研究综述

对基于定向天线的移动自组网邻居发现和接入控制关键技术进行研究.首先,介绍了其研究背景和意义;其次,分析了当前基于定向天线的MANET中存在的问题,并针对国内外研究现状,介绍了几种解决这些问题的方案.再次,着重介绍了两种比较成熟的基于定向天线的移动自组网邻居发现和接入控制算法SAND和PAMC.最后给出了基于定向天线的邻居发现和接入控制算法的下一步研究方向.     

构件化抽象工作模型在创建应用系统中的实践

提出构件化抽象工作模型的概念,分析了这一模型的体系结构,在原理上阐述了基于此模型进行软件开发的方法。详细研究了构件化抽象工作模型的技术路线和工作原理,分析各个模块之间相互作用的关系。在具体实践中,以实际项目中构造统计分析构件为例,将这一理论运用于分析设计和创建系统的各个阶段,把实际项目按照不同的应用、层次和粒度抽象成工作模型,设计和复用能独立完成特定功能的组件来组装软件,从而提高开发效率。     

资料搜集过程中搜索引擎合理化选择探讨

众所周知,我们处在一个信息爆炸的年代,信息、知识日新月异,面对如此海量的信息资源,我们应该如何从中选取出我们所需要的资料,成了我们必须考虑的重要问题.搜索引擎的出现,让这一切迎刃而解.借助它,我们可以有效搜集我们所需要的资料,从而不断提高学习和工作效率.     

一种基于散度差组合型文本特征降维方法

讨论了文本分类中特征降维的主要方法及其特点,分析了基于散度差准则的特征降维的原理和方法,在避开求逆矩阵问题的同时,通过对文本特征进行选择对文本特征集进行了第一次压缩,借助于加权散度差原理对特征集进行了二次抽取,在最低限度减少信息损失的前提下实现了特征维数的大幅度降低.试验结果表明,这种方法在文本分类上的效率较好.     

线性系统理论在分析分形-小波变换编码误差中的应用

本文利用线性系统理论对Davis所采用的自子树量化(SQS)分形-小波变换图像编码算法进行了深入分析,并发现SQS变换的吸引子与动力系统的稳定状态具有一致性.因此编码过程实际上就是对动力系统的参数进行编码.通过这种分析使我们了解到了尺度函数系数的量化误差是怎样影响解码图像的,从而可以更有效地控制解码误差,并且由此还可以更深刻地认识SQS算法中直接存储尺度函数系数方案给编、解码带来的巨大好处.     

基于经验值的分层PMTU探测算法

IPv6协议规定路由器不再对IP分组进行分段,因此端到端的PMTU探测成为IPv6应用中的关键环节,研究高性能的PMTU探测算法是当前下一代互联网领域中的研究热点.论文针对目前分层探测算法存在等概率探测点带来的发送探测包较多的问题,提出了一种基于经验值的分层探测算法,并从探测精度、总花费时间和总发包数等方面分析了该算法的测试性能,在CERNET2环境下,对比测试了一些常见PMTU算法的性能.实验结果表明,该算法的测试精度、测试耗时和发送探测分组数等性能方面都优于其他探测算法.     

Smart Identification Frameworks for Ubiquitous Computing Applications

We present our results of the conceptual design and the implementation of ubiquitous computing applications using smart identification technologies. First, we describe such technologies and their potential application areas, then give an overview of some of the applications we have developed. Based on the experience we have gained from developing these systems, we point out design concepts that we have found useful for structuring and implementing such applications. Building upon these concepts, we have created two frameworks based on Jini (i.e., distributed Java objects) and Web Services to support the development of ubiquitous computing applications that make use of smart identification technology. We describe our prototype frameworks, discuss the underlying concepts and present some lessons learned.     

铁电液晶的表面双稳的研究

本文研究了在不同的实验条件下铁电液晶的排列状态，实验中得到了表面双稳铁电液晶（ＳＳＦＬＣ）．分析了它的记忆机理，并测量了它的电光特性、响应时间及其锥角（ＣＯＮＥＡＮＧＬＥ）。最后我们讨论了双稳区的蜕变机理。     

Distributed decision fusion over fading channels in hierarchical wireless sensor networks

In this work, we investigate distributed decision fusion in hierarchical wireless sensor networks that are degraded by fading and noise. With the use of the complete fading channel state information (CSI), we first derive the likelihood ratio test (LRT) based optimum fusion rule, which we call LRT–CSI. Then, we relax the use of the complete CSI and only the exact phase information is employed together with channel envelope statistics (CS), and we develop another LRT based fusion rule named LRT–CS, which is computationally simpler to implement compared to LRT–CSI. Finally, we analyze the detection performance of all the proposed fusion rules through extensive numerical results.     

IDEAS05: Unifying Models of Test Cases and Requirements

In industry, due to market pressures, it is common that the system requirements are out of date or incomplete for certain parts of the system. Nevertheless, we can always find up to date test cases which implicitly complements the related requirements. Therefore, instead of simply using test cases to detect software failures, in this paper we present an approach to update requirements using test cases. To accomplish this, we first assume that both requirements and test cases are formally documented; we reuse previous works that provide such models automatically as CSP formal specifications. Thus, we formally define a merge operation using the operational semantics of CSP. Finally, we use part of a real case study to experience the proposed approach.     

Inverse Class-AB功率放大器线性度和效率分析

inverse Class—AB模式可以使功率放大器得到更好的性能，但是传统的教科书中并没有这种模式的理论分析因此有必要从理论上对inverse Class-AB模式进行分析。通过对输出波形傅里叶函数的研究可以得到最大输出电压摆幅以及计算最大功率。通过Volterra序列分析法以out—of-band抵消技术我们分析这种模式功率放大器的非线性。最后我们进行了大量的仿真以验证所提出的理论。     

The Power of Tuning: A Novel Approach for the Efficient Design of Survivable Networks

Current survivability schemes typically offer two degrees of protection, namely full protection (from a single failure) or no protection at all. Full protection translates into rigid design constraints, i.e., the employment of disjoint paths. We introduce the concept of tunable survivability that bridges the gap between full and no protection. First, we establish several fundamental properties of connections with tunable survivability. With that at hand, we devise efficient polynomial (optimal) connection establishment schemes for both and protection architectures. Then, we show that the concept of tunable survivability gives rise to a novel hybrid protection architecture, which offers improved performance over the standard and architectures. Next, we investigate some related QoS extensions. Finally, we demonstrate the advantage of tunable survivability over full survivability. In particular, we show that, by just slightly alleviating the requirement of full survivability, we obtain major improvements in terms of the ldquofeasibilityrdquo as well as the ldquoqualityrdquo of the solution.     

雷达数据处理算法的仿真研究

文中介绍了一种雷达数据处理的算法。首先简要介绍了雷达数据处理系统的工作原理和流程,然后重点研究了雷达数据处理的关键算法的原理和公式,建立起系统模型,最后,针对雷达数据处理算法进行了仿真结果并对结果进行了分析。     

On Non-homogeneous Generalized Linear Discrete Time Systems

In this article, we study the initial value problem of a class of non-homogeneous generalized linear discrete time systems whose coefficients are square constant matrices. By using matrix pencil theory we obtain formulas for the solutions and we give necessary and sufficient conditions for existence and uniqueness of solutions. Moreover, we provide some numerical examples.     

变速率调制解调器的DSP实现

介绍了一种较为简单的抗干扰方式－－降低信息速率，分析了当系统采用该方式时系统误码率、误分组概率及信道利用率的提高并给出了仿真结果，最后介绍了如何用数字信号处理芯片Ｃ５０实现了可变速率的调制解调器。     

离子注入铌酸锂平面波导双折射特性的研究

为了获得折射率信息,采用UT00-FPD型椭偏仪对5mm×10mm×1mm铌酸锂晶体及注入镓的铌酸锂晶体波导的双折射特性进行了测量.首先对铌酸锂晶体测量结果进行建模及数据处理,得到晶体在190nm～1700nm之间的双折射特性;在此模型的基础上,进一步对注入镓的铌酸锂晶体波导进行了建模和数据处理,得到了波导层的双折射率的分布.所得表征结果为铌酸锂晶体波导在光子器件中的应用提供了有用的信息.     

一种多出口的WiMAX Mesh回程网络资源调度算法

由于WiMAX Mesh网络可以有效保证网络的QoS,因此有可能将其应用于电信级的回程网络.本文分析了WiMAX Mesh网络的调度机制和单出口 WiMAX Mesh网络存在的问题,提出了一种多出口WiMAX Mesh网络组网方案,在该方案的基础上提出了全局最优的调度算法,并给出了把该算法应用到实际WiMAX Mesh网络中的详细步骤.本文对具有20个和50个SS节点的Mesh网络进行了仿真,对算法的性能和效果进行了验证.仿真结果表明,本算法可以把调度效率提高53%～70%.