网络虚拟化环境下的跨域虚拟网络映射是指当物理网络由多个自治域构成时,以最小化虚拟网络映射开销为目标,将虚拟网络请求恰当地划分为多个虚拟子网请求,并分别指派给相应自治域以完成映射.资源匹配和虚拟网络划分是跨域虚拟网络映射中的两个关键阶段.然而,现有的资源匹配算法无法支持精确的数值属性匹配,也无法满足虚拟网络用户对表达多样化映射约束的需求,故实用性不高.此外,虚拟网络划分属于NP问题,目前也缺乏高效的求解方法.针对上述两个阶段中存在的问题,分别提出了基于OWL及SWRL的资源匹配算法和基于遗传算法的虚拟网络划分算法.理论分析证明了该方法的正确性.仿真实验从效率、性能及稳定性方面验证了该方法的有效性.

关键词：网络虚拟化；跨域虚拟网络映射；资源匹配；知识描述；虚拟网络划分；遗传算法

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复杂图像文字识别是基于内容图像检索的一个重要研究方向.针对图像中的文字可能存在倾斜、光照不均、噪音干扰和边缘柔化等多种异态问题,提出一种有效的异态汉字识别方法,称作SC-HOG.首先,利用稀疏编码得到基向量和稀疏系数,通过重构图像滤除噪音、处理边缘柔化;然后,利用梯度方向直方图抽取复原图像的汉字边缘梯度特征,削弱倾斜和光照的影响;最后,将获取的特征向量送入分类器,实现异态汉字的识别.通过合成数据集和真实数据集两方面的实验来验证SC-HOG方法的有效性:前一方面实验结果表明,SC-HOG方法对于倾斜、光照不均、噪音干扰和边缘柔化等异态情况有较强的鲁棒性;后一方面实验结果表明,SC-HOG方法在原生数字图像和场景图像真实样本集上也能取得较好的结果.

关键词：稀疏编码；梯度方向直方图；增量线性决策分析；汉字识别；文档图像处理

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关键词：电商；旅游；市场空间

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报告包括电子商务方面的重要观点、政策与环境、网购平台、行业应用、电商物流、电商金融等研究。

关键词：政策环境；网购平台；电商物流；电商金融

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关键词：产业园区；光谷；高新科技；风险

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Recent investigations into the fundamental limits of mobile ad hoc networks have produced a physical layer method for approaching their capacity. This strategy, known as interference alignment, requires cooperation, rather than competition, among the transceivers in the network. Under ideal circumstances, every user can achieve reliable communication at rates approaching one half of the interference-free capacity. Unfortunately, prior research on interference alignment makes many assumptions that make it difficult to realize interference alignment in practice. This report summarizes the PI's work on realizing interference alignment in multiple-input multiple-output (MIMO) communication channels. The emphasis is on networks where clusters of users cooperate together, since this provides a good balance between network overhead and performance. One contribution was to devise a way to add new users to an existing cluster of interference aligned users. Different algorithms were devised as a function of the number of antennas in the network. Another contribution was to analyze interference alignment in a network with random clusters of users. The cases where interference alignment was preferred to other simpler communication strategies was characterized. Another contribution was to determine the impact of distributing the antennas. It was found that distributed antennas lead to higher performance with interference alignment, and new algorithms were designed to achieve that performance. A final contribution was to prototype an interference alignment network. A distributed prototype was constructed with over-the-air synchronization and feedback, demonstrating the viability of interference alignment for small networks in practice.

关键词：天线;集群;通信和广播系统;通信网络

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The emerging wireless world is expected to be characterized from the demand for new, diversified applications/services, the expanded use of wireless and the need for increased efficiency in resource provisioning and utilization. Therefore, the resource usage in an opportunistic manner would provide a solution towards this direction. Opportunistic networks (ONs) and Cognitive Management Systems (CMSs) for cellular extensions are one of the emerging communication paradigms in wireless mobile communications. For the cooperation of CMSs, specific mechanisms need to be defined in order to increase the accuracy of obtained knowledge on the context of the operational environment. Also, a cooperation mechanism is required for efficient coordination between the infrastructure and the devices in the scope of an ON. Therefore, Control Channels (CCs) are required for the exchange of information and the coordination between CMSs. Consequently, this work focuses on the definition of the needed interfaces that are introduced in order to enable communication between the cognitive management systems and also to the related groups of information that is needed to be conveyed between these systems in order to ensure proper interaction. Finally, an indication of the amount of information conveyed through CCs is provided in order to be able to assess the impact to the network of control-related transmitted information.

关键词：无线通信；互联网；认知管理系统；机会网络

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关键词：可重构系统；通信；吞吐量

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Navigation requires knowledge of current location and a planned destination. This is true with manned vehicles and unmanned vehicles. There are many ways to acquire the current location, including global positioning system (GPS), triangulation, radar, and dead reckoning. Today GPS is the most reliable and accurate navigation technique when there is a clear, unobstructed view of the satellite constellation. Various sensors can be used to perform indoor navigation; however, when the vehicle is autonomous the sensors need to provide the exact location to the system. This research determined if using a template replay strategy has the same RNR performance as using an analog noise source. Using the template replay approach, each RNR node has a priori knowledge about the transmitted waveforms of other nodes. The analysis here revealed that modifications do not significantly alter RNR functionality. The analysis revealed that even at SNIR equal to 0 dB, there are no parameters that can be reliably extracted other than transmitted signal bandwidth and transmitted template length; the transmitted message length was able to be extracted because the message was repeated over and over. If the message was not replayed the analysis showed that there would be no ability to extract parameters. Finally, by using the RNR to transmit digitally generated templates, digital communication is possible and the symbol error rate (SER) is traceable to simulated SER.

关键词：自主导航;数字通信;室内导航;截获概率低;多基地雷达

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During Phase one Option period, Trex performed extensive research into THz-range passive and active component that will be required make the Phase two hardware. The design of a custom MMIC was completed so it could be ordered processed with the once a year Pizza mask process at UMS. These parts are expected to arrive later this year when the Phase 2 contract is awarded and results in a significant cost saving in the development of a custom mixer. In addition the source pricing for the MMIC amplifier was also completed. This process took much longer than expected and this will speed up the process of betting parts during the second phase of the program. In addition direction of the overall mechanical configuration was outlined to speed up the process for the detailed design that will be undertaken in the next phase of the program. The radios will be designed to communicate in a half-duplex at 3 Gbps and full duplex using TDD mode at 1 Gbps data rate. The details of the TDD mode being much more complex were looked into in more detail during the option phase.

关键词：毫米波千兆; 通信;收发器;无线链路

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