三氧化钨催化氧化环己烯合成己二酸

无需有机溶剂、酸性配体及相转移剂,以30%H2O2为氧源,单独使用三氧化钨作催化剂催化氧化环己烯合成己二酸即可达到较高的产率和纯度。当三氧化钨用量为5.0m m ol,W O3:环己烯:H2O2的摩尔比为1:40:176时,在回流温度下反应6h,己二酸分离产率为75.4%,己二酸纯度99.8%。三氧化钨催化剂重复使用4次,己二酸的分离产率仍可达到70%以上。结合FTIR和XRD分析证明了三氧化钨催化氧化环己烯反应过程中催化剂的结构稳定性和重复使用性。     

并行应用程序调度策略研究

为了提高并行应用程序在异构平台上的执行效率,从范例、粒度角度对并行组件分类并设计相应模型,从而实现串行、消息并行或内存并行共享,粗、精、中粒度均可的各类范例的运行,同时也可针对组件的编程语言对范例进行编程。基于对组件范例、粒度的描述及资源使用的信息,进一步提出了组件调度策略,经测试表明组件模型和调度策略改善了并行应用程序的执行,提高了异构平台资源的利用率。     

基于异构多核SoC的LT码编码硬件化技术研究

对异构多核SoC进行建模分析,将LT编码在异构多核SoC上的实现问题转化为LT码编码子任务在异构多核SoC上的映射问题,并给出了基于遗传算法的任务映射方法。最后基于XILINX ZYNQ-7000异构多核SoC实现了LT码编码器。实验结果表明,所设计的LT码编码器能够 满足不同的性能和资源需求,增加了硬件平台的实用性和应用系统设计的灵活性。     

实时异构集成数据自适应模板解析算法

工业中实时监控系统的实时异构集成数据在解析存储时需要适应用户需求多样性和可变性的特点,因此集成数据的解析成为一个难点。以环境在线监控系统为应用背景,提出了针对实时异构集成数据的自适应模板数据解析思想。数据解析前,根据集成数据,以用户需求为基础设计的用户表以及定义的模板构建规则,构造描述集成数据与用户表映射关系的自适应模板。解析算法根据模板对集成数据进行解析分类。该算法只根据模板的描述对数据进行解释,具有良好的通用性以及可拓展性。通过实际数据进行测试,结果表明提出的自适应模板解析算法具有良好的性能,能够很好地适应用户需求多样性和可变性的特点。     

电力无线通信异构多网共存环境中的网络选择算法

综合考虑电力业务需求和无线专网性能因素,针对邻域网、LTE无线专网、WiMAX无线专网和230 MHz无线专网等构成的异构多网混合共存场景,提出一种网络选择算法。该算法以AHPTOPSIS算法为基础,首先构建能表征候选网络与决策属性之间关系的决策矩阵,归一化处理获得归一化决策矩阵;利用AHP算法,依据不同业务类型下决策属性与网络性能之间的相对关系定义权重,对归一化决策矩阵加权获得加权归一化决策矩阵;然后对TOPSIS算法进行改进,依据加权归一化决策矩阵确定正负理想值,利用正理想值与候选网络之间的最小距离以及负理想值与候选网络之间的最大距离确定理想网络,计算各候选网络与理想网络之间的有效距离;据此执行候选网络排序和最佳网络选择,以避免运行TOPSIS算法可能存在的排序异常。仿真结果表明,该算法能根据电力业务需求对候选网络进行正确排序和最优选择,且能在满足业务服务质量的同时,提高资源利用率。     

Topic hierarchy construction from heterogeneous evidence

Existing studies on hierarchy constructionmainly focus on text corpora and indiscriminately mix numerous topics, thus increasing the possibility of knowledge acquisition bottlenecks and misconceptions. To address these problems and provide a comprehensive and in-depth representation of domain specific topics, we propose a novel topic hierarchy construction method with real-time update. This method combines heterogeneous evidence from multiple sources including folksonomy and encyclopedia, separately in both initial topic hierarchy construction and topic hierarchy improvement. Results of comprehensive experiments indicate that the proposed method significantly outperforms state-of-theart methods (t-test, p-value < 0.000 1); recall has particularly improved by 20.4% to 38.7%.     

Grounded Symbolic Communication between Heterogeneous Cooperating Robots

In this paper, we describe the implementation of a heterogeneous cooperative multi-robot system that was designed with a goal of engineering a grounded symbolic representation in a bottom-up fashion. The system comprises two autonomous mobile robots that perform cooperative cleaning. Experiments demonstrate successful purposive navigation, map building and the symbolic communication of locations in a behavior-based system. We also examine the perceived shortcomings of the system in detail and attempt to understand them in terms of contemporary knowledge of human representation and symbolic communication. From this understanding, we propose the Adaptive Symbol Grounding Hypothesis as a conception for how symbolic systems can be envisioned.     

Robust output tracking for heterogeneous double-integrator dynamics with external disturbance

This paper studies the robust output tracking for heterogeneous double-integrator dynamics with external disturbance. It is assumed that there exist interactions among agents and their neighbours. All the agents have non-identical dynamics with others, and all the system matrices are unknown. A state feedback control protocol with only neighbours information is proposed based on a distributed compensator for non-identical dynamics and an internal-model compensator for the unknown parts. By the algebraic graph theory and matrix theory, sufficient conditions are given to guarantee that all the outputs of the agents converge to the reference output as time tends to infinity. Finally, two numerical simulations are provided to illustrate the effectiveness of the theoretical results.     

3G与WLAN及其相互融合网络的接入认证机制研究

对主流的移动通信、无线局域网、异构无线融合网络三种形式的无线网络接入认证机制从采用技术上进行分类和分析,从无线网络接入认证机制的发展历史、现状、存在问题以及应用的技术加以分析总结,并结合现在的认证技术进行展望,为异构无线融合网络的接入认证机制提供思路。     

An Efficient Handoff Decision Algorithm for Vertical Handoff Between WWAN and WLAN

Vertical handoff is one significant challenge for mobility management in heterogeneous wireless networks. Compared with horizontal handoff, vertical handoff involves different wireless network technologies varying widely in terms of bandwidth, delay, coverage area, power consumption, etc. In this paper, we analyze the signal strength model of mobile node and present a new vertical handoff decision algorithm. This algorithm can adapt to the change of mobile node＇s velocity and improve the handoff efficiency significantly. We analyze the algorithm＇s performance and the effect of different parameters on handoff triggering. In addition, we propose three performance evaluation models and verify the algorithm＇s feasibility and effectiveness in simulations.