一种基于信任度的自组安全互操作方法

提出了基于信任度的自组安全互操作方法,引入信任度描述自治域和用户正确参与协作的概率.自治域对用户的信任度由二者的直接交互经验以及其他域对用户的评价共同决定,满足信任策略要求的用户允许执行角色.用户的恶意历史行为将会降低其信任度,从而影响执行角色的范围.自治域对其他域的信任度由对用户的评价与直接经验的偏差根据加权主要算法反馈更新.自治域的恶意评价影响其推荐信息的可信程度.实验结果表明,该方法能够有效地抵御欺骗和恶意行为.

移动卫星网络资源发现技术研究

资源发现技术是根据给定的资源描述，在网络中自动找到相应资源的技 术，该技术能够智能地满足网络中应用和指挥任务执行时对资源信息的需求， 并且能够为资源的管理和监控提供一定支持。 现有的资源发现技术研究主要针对地面的网格、P2P网络和移动Ad hoc 网络等。卫星网络作为一种特殊的移动网络，其中节点的星载CPU 处理能力 和存储能力都无法与地面设备相提并论。同时，由于卫星网络具有拓扑结构 动态变化、空间无线信道时延长、误码率较高等特性，使得现有的地面网络 资源发现协议不能直接应用于卫星网络，因此设计高效的卫星网络资源发现 协议将有助于促进卫星网络的复杂应用和智能控制。 本文提出了一种针对移动卫星网络的分布式资源发现协议SatRDP， 针对 卫星网络中节点的移动性、星间链路时延和不同星座组网结构等情况，设计 了协议的体系结构以及相应的分布式资源信息存储和广告策略、需求路由和 回溯策略。经过分析，SatRDP 能够更好地适应移动卫星网络，提高资源发现 成功率，节省卫星节点的存储资源，在一定程度上降低协议开销。 最后，设计了仿真实验平台，对算法进行了初步的实验，并与传统的分 布式资源发现协议 FLOOD 进行比较。实验结果表明，SatRDP 协议更适合卫 星网络环境，有更高的发现成功率、发现效率和更小的需求包开销。最后总 结并指出了移动卫星网络资源发现技术进一步的研究方向。

MANET中TCP Vegas拥塞控制的端到端改进方法

TCP Vegas通过往返时间的最小值baseRTT来进行拥塞控制,因此获取准确baseRTT的值至关重要.在MANET中,不断变化的网络拓扑会导致baseRTT的测量出现严重偏差,从而降低了吞吐量,而TCP Vegas在拥塞避免阶段发生路由变化但没有引起丢包或失序现象时,已有的端到端启发式方案很难进行识别.采用回落探测方法识别路由变化,进而调节往返时间的最小值以改善TCP Vegas拥塞控制算法在MANET中的性能.

移动自组网中基于节能的AODV路由协议改进

在AODV路由算法的基础上,综合考虑节点剩余能量和跳数,提出了一种新的节能路由策略.该策略同时对数据包和路由控制包进行功率控制,改进了Hello机制.仿真结果显示该策略显著地提高了节能效果,延长了网络的生存时间.

大规模多数据库系统的互操作机制

Sharing data among disparate databases has so far mostly been achieved through some form of ad-hoc schema integration. This approach becomes less tractable as the number of participating database increases. In this paper,we first present the primary problems to be resolved in large multidatabase systems and discuss the autonomy and heteroheneity of large multidatabase systems and then describe a coalition agent mechanism to implement large multidatabase systems interoperation.

Resolving Ambiguity in Nonmonotonic Inheritance Hierarchies

This paper describes a theory of inheritance theories. We present an original theory of inheritance in nonmonotonic hierarchies. The structures on which this theory is based delineate a framework that subsumes most inheritance theories in the literature, providing a new foundation for inheritance. * Our path-based theory is sound and complete w.r.t. a direct model-theoretic semantics. * Both the credulous and the skeptical conclusions of this theory are polynomial-time computable. * We prove that true skeptical inheritance is not contained in the language of path-based inheritance. Because our techniques are modular w.r.t. the definition of specificity, they generalize to provide a unified framework for a broad class of inheritance theories. By describing multiple inheritance theories in the same "language" of credulous extensions, we make principled comparisons rather than the ad-hoc examination of specific examples makes up most of the comparative inheritance work.

Near-Optimal Distributed Failure Circumscription

Small failures should only disrupt a small part of a network. One way to do this is by marking the surrounding area as untrustworthy --- circumscribing the failure. This can be done with a distributed algorithm using hierarchical clustering and neighbor relations, and the resulting circumscription is near-optimal for convex failures.

Specialization of Perceptual Processes

In this report, I discuss the use of vision to support concrete, everyday activity. I will argue that a variety of interesting tasks can be solved using simple and inexpensive vision systems. I will provide a number of working examples in the form of a state-of-the-art mobile robot, Polly, which uses vision to give primitive tours of the seventh floor of the MIT AI Laboratory. By current standards, the robot has a broad behavioral repertoire and is both simple and inexpensive (the complete robot was built for less than $20,000 using commercial board-level components). The approach I will use will be to treat the structure of the agent's activity---its task and environment---as positive resources for the vision system designer. By performing a careful analysis of task and environment, the designer can determine a broad space of mechanisms which can perform the desired activity. My principal thesis is that for a broad range of activities, the space of applicable mechanisms will be broad enough to include a number mechanisms which are simple and economical. The simplest mechanisms that solve a given problem will typically be quite specialized to that problem. One thus worries that building simple vision systems will be require a great deal of {it ad-hoc} engineering that cannot be transferred to other problems. My second thesis is that specialized systems can be analyzed and understood in a principled manner, one that allows general lessons to be extracted from specialized systems. I will present a general approach to analyzing specialization through the use of transformations that provably improve performance. By demonstrating a sequence of transformations that derive a specialized system from a more general one, we can summarize the specialization of the former in a compact form that makes explicit the additional assumptions that it makes about its environment. The summary can be used to predict the performance of the system in novel environments. Individual transformations can be recycled in the design of future systems.

Modelling uncertainty in agricultural image analysis

C.M. Onyango, J.A. Marchant and R. Zwiggelaar, 'Modelling uncertainty in agricultural image analysis', Computers and Electronics in Agriculture 17 (3), 295-305 (1997)

Double Jeopardy Without Parameters: Re-characterization in International Criminal Law

Olusanya, O. (2004). Double Jeopardy Without Parameters: Re-characterization in International Criminal Law. Series Supranational Criminal Law: Capita Selecta, volume 2. Antwerp: Intersentia. RAE2008

W SPRAWIE DODATKOWYCH MANDATÓW DO PARLAMENTU EUROPEJSKIEGO

Zwiększanie składu Parlamentu Europejskiego jest zjawiskiem zrozumiałym i związanym z rozszerzaniem się Unii o kolejne państwa. Zazwyczaj zwiększenie składu PE następuje wraz z rozpoczęciem nowej kadencji. Niniejszy artykuł omawia jednakże przypadek zwiększenia składu PE podczas trwającej kadencji. Konieczność zwiększenia liczby mandatów przypadających części państw wywołana została wejściem w życie Traktatu Lizbońskiego, przewidującego zwiększenie liczby mandatów do PE z 736 do 754. W Traktacie nie umieszczono przepisu wskazującego, że przepisy dotyczące składu PE wejdą w życie od nowej kadencji, co zrodziło szereg problemów związanych przede wszystkim z wyborem trybu obsady dodatkowych mandatów. Rada Europejska zaproponowała 3 sposoby obsady dodatkowych mandatów: na podstawie wyników wyborów z czerwca 2009 r., w drodze wyborów przeprowadzonych ad hoc, przez parlamenty narodowe spośród swych członków. Wszystkie państwa członkowskie, w tym Polska, zdecydowały się na wybór pierwszego ze wskazanych sposobów. Zdaniem autora, przyjęty w Polsce sposób obsady dodatkowego mandatu dokonany na podstawie przeprowadzonych już wyborów jest wątpliwy z punktu widzenia zgodności z Konstytucją RP.

Perfis de risco na condução de veículo em estado de embriaguez

Projecto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciada em Criminologia

Measuring Bottleneck Bandwidth of Targeted Path Segments

Accurate measurement of network bandwidth is crucial for flexible Internet applications and protocols which actively manage and dynamically adapt to changing utilization of network resources. These applications must do so to perform tasks such as distributing and delivering high-bandwidth media, scheduling service requests and performing admission control. Extensive work has focused on two approaches to measuring bandwidth: measuring it hop-by-hop, and measuring it end-to-end along a path. Unfortunately, best-practice techniques for the former are inefficient and techniques for the latter are only able to observe bottlenecks visible at end-to-end scope. In this paper, we develop and simulate end-to-end probing methods which can measure bottleneck bandwidth along arbitrary, targeted subpaths of a path in the network, including subpaths shared by a set of flows. As another important contribution, we describe a number of practical applications which we foresee as standing to benefit from solutions to this problem, especially in emerging, flexible network architectures such as overlay networks, ad-hoc networks, peer-to-peer architectures and massively accessed content servers.