一种博弈竞争选择的异构无线网络最优接入策略

为了提高异构无线网络的信息传输速率和网络利用率,减少网络的系统开销,提出一种博弈竞争选择的异构无线网络最优接入策略算法,该算法在考虑了实际带宽的情况下引入了代价因子,并得到最大化的网络信息传输速率.在接入网络的选择上,通过采用基于博弈模型和最优接入策略的博弈模型,通过多项服务质量指标来计算综合竞争值,从而通过竞争值大小来选择最优的接入网络.实验仿真及数据结果表明,相比另外两种异构接入网络的选择算法,该算法具有带宽资源利用率和网络信息传输速率更高的优势.     

基于博弈论的异构融合网络接入选择方法研究

各种异构接入网络的无缝融合是下一代网络的显著特征之一,不同网络技术接入形式的多样化使得多网络接口的用户终端可自主选择对用户最为有利的接入网络(或SP,Service Provider)获得互联网服务.文中给出一种面向用户可视化可操作的异种网络接入选择实现机制,该机制采用一种量化接入系统服务质量的统一评价模型及基于最优用户性价比的网络选择决策方法,同时依据不同接入网络之间的合作与非合作关系以及SP与用户之间的竞争关系,引入博弈论方法建立网络价格策略的两种博弈模型,通过求解模型的纳什均衡价格及共谋价格,确定网络优化定价机制.仿真结果比较了异构网络融合环境下的各接入网络在非合作和合作博弈模式中的优化定价机制及获得的收益特性,并比较了不同博弈场景下用户选择接入网络的性价比.     

基于演化博弈的用户接入机制

用户接入问题就是无线终端选择接入某个服务基站的问题。用户接入可以看作无线资源管理的第一步,对于网络性能有着重要的影响,在实现负载均衡、控制干扰、提高频谱和能量效率等方面起着非常重要的作用。针对包含宏基站和全双工小基站的多层异构网络特点,考虑了分离多接入机制,即允许一个终端在上行和下行接入到不同的多个基站,从而实现性能的提升。在此基础上,将异构网络中的上行下行分离多接入的用户接入问题建模成一个演化博弈问题,其中用户是博弈方,相互之间进行资源的竞争,基站的接入选择就是博弈中的策略,每个用户希望能通过策略的选择实现自身效用的最大化。此外,基于演化博弈和强化学习设计了低复杂度自组织用户接入算法,用户可以根据当前的策略选择收益来进行策略调整,并最终达到均衡状态,实现了用户公平性。最后通过大量的仿真实验验证了所提方法的有效性。     

异构无线网中面向QoS的马尔可夫选择策略

针对移动终端在异构网络环境下,需要在垂直切换过程中进行网络选择的问题,提出一种面向QoS的马尔可夫选择决策算法,通过对算法模型合理化构建过程与异构环境特点的紧密结合、报酬函数的正确定义与求解,可以为用户选择合适的接入网络,最大程度地满足在异构网络环境中用户QoS的长期效益。仿真结果表明,该算法可以有效提高判决水平,改善业务的QoS。     

基于演化博弈的多用户网络选择算法

无线通信技术的发展和演进,使得多种广域蜂窝网和大量无线局域网共存、重叠。针对热点区域,密集分布的大量用户同时发起同种业务请求应用场景,提出一种基于演化博弈的多用户网络选择算法,依据选择网络的用户数设计效用函数,给出了演化博弈的复制动态方程。与RSSI算法的对比仿真结果表明：该算法能快速达到演化均衡,用户平均收益高于RSSI算法,接入网络的用户分布更均衡,能合理利用网络资源。     

基于粗糙集理论和层次分析法的异构无线网络接入选择算法

针对异构无线网络环境下的基于负载均衡的接入选择算法未能全面考虑判决因素以及合理反映候选网络综合性能水平的问题,利用多属性决策理论提出一种异构无线网络接入选择算法。该算法在满足多属性判决的基础上,采用粗糙集理论和层次分析法确定接入判决指标的主观和客观权重,并通过最小二乘法对主客观权重进行折中选择,判决过程兼顾了网络的综合性能水平和用户的喜好,提高了网络接入选择的准确性和合理性。仿真结果表明,该算法相对于参考算法有效降低了系统阻塞率,并有利于异构网络之间的负载均衡。     

基于朴素贝叶斯的室内VLC网络天线选择方法

在室内多天线多用户可见光通信(VLC)网络中,为了改善在发射天线和用户数量增多的情况下,最优天线选择算法存在时间复杂度过高问题,将朴素贝叶斯(NB)方法应用于室内多用户VLC网络下行链路发光二极管(LED)选择问题中.首先,将该LED选择任务建模为多分类问题,利用用户已知信道状态信息生成训练样本集,并通过VLC网络多用户通信和速率最大生成对应类标签;其次,利用生成的训练样本集,通过NB方法得到分类器模型;最后,将训练得到的分类器模型应用于新用户的LED选择.仿真分析表明,与最优多用户VLC网络LED选择算法相比,所提出的基于NB的LED选择方案可以有效地降低时间复杂度,在算法复杂度和用户传输和速率之间实现了较好的平衡.     

马尔科夫模型在异构无线网络选择中的应用

研究异构无线网络接入选择问题.选择网上最佳资源连接,由于通信过程存在随机性,单一方法难以确定最优接入网络.为满足异构无线网络选择准确性,提出一种马尔科夫的异构无线网络选择算法.首先选择网络性能指标,然后采用层次分析法确定网络性能指标权重,再通过马尔科夫模型计算每一个网络的期望总同报值,并选择回报值最大的网络作为当前最优接入网络进行仿真.仿真结果证明,相对于传统网络选择算法,马尔科夫算法能够根据用户需求选择到最优接入网络,可以有效地减少切换次数,提高有效吞吐量和降低丢包率,提高了异构性网络选择的准确性.     

异构无线网络选择算法的仿真研究

研究异构无线网络选择问题.异构无线网络选择是下一代无线网络的关键技术及多网融合的基础,决策指标相当多,传统判决指标权重方法具有片面性,无法为用户提供最佳网络选择服务.为了提高异构无线网络选择的准确性,把层次分析和灰色关联评价法结合起来,提出一种组合的异构无线网络选择算法.通过对影响网络选择的指标进行分析,用层次分析法和方根法确定网络决策指示的权重,最后对备选网络进行灰色关联选择,选择最优接入网络.仿真结果证明,相对于传统网络选择算法,更加客观准确地选择与用户需求最佳匹配网络,并降低用户的接入成本,从而可以满足用户的业务需求,为异构无线网络设计提供了参考.     

异构蜂窝系统中动态联合呼叫接纳控制算法

针对异构蜂窝系统的接纳控制问题,设计了一种动态联合呼叫接纳控制算法。该算法采取TOPSIS法选择最优接入网,根据系统负载分布情况动态调整网络资费,对用户的接入选择决策施加影响,以均衡网络间负载;针对不同的呼叫优先级,采取多级接入阈值及动态带宽分配策略,在接入控制环节进一步改善系统性能及用户体验。仿真结果表明,该算法在重视用户偏好的同时实现了负载均衡,降低了呼叫阻塞率和掉线率。     

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QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

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。