复杂电磁环境建模与可视化研究综述

复杂电磁环境建模与可视化研究在民用通信、军用电子战领域的应用不断发展。在介绍了复杂电磁环境基本概念的基础上,首先系统阐述了复杂电磁环境建模的理论方法和数据场的可视化具体方法。然后对国内外复杂电磁环境建模与可视化研究现状进行了分析,对复杂电磁环境中雷达这一主要设备的电磁环境建模进行了研究,并对模型的复杂度、预测精度进行了总结与比较;针对电磁体数据场数据量的海量特性,对电磁体数据场可视化的基本思想、加速技术、适用范围分别从图形硬件加速和软件算法优化两方面进行了归纳与总结;阐述了仿真系统的总体框架设计思想,并设计了一个复杂电磁环境仿真可视化系统。最后对复杂电磁环境建模与可视化未来研究方向进行了展望。     

基于数据同化的图像融合方法研究

数据同化凭借其在数值预报中将观测数据与理论模型相结合的特点,目前广泛应用于遥感图像处理及图像融合领域。文中介绍了数据同化的含义和数据同化系统的构成,并分析了其应用于图像融合的原理;结合现有的研究成果着重分析了数据同化框架下结合不同优化算法的图像融合方法,并对其进行分类比较,给出了各方法的优缺点和研究成果及应用;最后在总结了各种基于数据同化的图像融合方法普遍存在的问题的基础上,探讨了进一步发展与研究的方向。     

异构网络中SNMP数据采集监测系统研究

针对异构网络中数据信息监测的要求,研究在网络异构环境中数据采集的实现方法。分析并使用简单网络管理协议（SNMP）和管理信息库（MIB）,设计并实现一个能够对异构网络环境下的主机资源进行实时采集的系统软件。该系统使用关系数据库保存所有主机资源信息,并通过绘图的方式生成实时的主机资源占用曲线,以便对主机在一定时期内的资源占用状况进行综合分析。系统运行结果表明,可以有效地对网络主机资源进行全面监测,及时掌控网络资源运行状况。     

Moodle平台数据挖掘方法设计与实现

教育数据挖掘是一个新兴的研究方向。如何把存储在教育软件系统中的数据转变为有意义的信息,并为教育决策、优化教学过程服务,已成为大多数教育工作者所关注的内容。文中总结了当前教育数据挖掘的研究现状,介绍了一种基于Excel的简单数据挖掘方法。该方法利用模糊C均值聚类算法,对Moodle平台积累的日志数据进行分析,找出有相似学习行为的学生,为学习社区的小组划分和研究学习模式服务。实验表明,该方法能够更准确地对学生进行分类,而且操作更为简单、方便。     

Feature selection on probabilistic symbolic objects

In data analysis tasks, we are often confronted to very high dimensional data. Based on the purpose of a data analysis study, feature selection will find and select the relevant subset of features from the original features. Many feature selection algorithms have been proposed in classical data analysis, but very few in symbolic data analysis （SDA） which is an extension of the classical data analysis, since it uses rich objects instead to simple matrices. A symbolic object, compared to the data used in classical data analysis can describe not only individuals, but also most of the time a cluster of individuals. In this paper we present an unsupervised feature selection algorithm on probabilistic symbolic objects （PSOs）, with the purpose of discrimination. A PSO is a symbolic object that describes a cluster of individuals by modal variables using relative frequency distribution associated with each value. This paper presents new dissimilarity measures between PSOs, which are used as feature selection criteria, and explains how to reduce the complexity of the algorithm by using the discrimination matrix.     

计算文本的情感描述值的算法

随着互联网信息的高速发展,越来越多的人参与到信息的制造者队伍中,对于信息处理提出了更高的要求。计算文本的情感描述值对于衡量文本的极性信息具有重要的意义。首先对文本内容进行预处理,挑选出可以决定文本极性的句子;然后对各个子句进行情感描述值的计算;最后将子句的情感进行综合计算,得出文本的情感描述值。并且对文本长度、句法结构等因素进行了综合分析。实验结果表明,采用该算法计算文本信息具有较高的准确率和速度,对于大规模处理流数据情况下的情感信息值的计算具有较好的适用性。     

PAIDD: a hybrid P2P-based architecture for improving data distribution in social networks

Rapid growth in social networks(SNs)presents a unique scalability challenge for SN operators because of the massive amounts of data distribution among large number of concurrent online users.A request from any user may trigger hundreds of server activities to generate a customized page and which has already become a huge burden.Based on the theoretical model and analytical study considering realistic network scenarios,this article proposes a hybrid P2P-based architecture called PAIDD.PAIDD fulfills effective data distribution primarily through P2P connectivity and social graph among users but with the help of central servers.To increase system efficiency,PAIDD performs optimized content prefetching based on social interactions among users.PAIDD chooses interaction as the criteria because user’s interaction graph is measured to be much smaller than the social graph.Our experiments confirm that PAIDD ensures satisfactory user experience without incurring extensive overhead on clients’network.More importantly,PAIDD can effectively achieve one order of magnitude of load reduction at central servers.     

Measurement of intrinsic rates for homogeneous gas‐phase reactions at high temperatures

A coiled quartz tubular reactor has been designed to measure the intrinsic reaction kinetics for homogeneous reactions at high temperatures up to 1100°C. Actual gas residence times were less than 100 ms. A simple and well‐studied test reaction (i.e., the decomposition of nitrous oxide, N₂O), with published intrinsic kinetics, was used to verify the operation of the experimental reactor. For this system, Peclet numbers (Pe = uL/DL) computed from experimental conversion data were greater than 1000, indicating that the plug flow assumption could be used with this reactor system to determine intrinsic rate expressions with errors of less than 5% for the conditions studied.     

马钢CSP卷取机夹送辊控制的优化措施

针对马钢CSP热轧卷取夹送辊的缠辊故障,提出相应的优化改造措施。     

水计量系统数据传输稳定性的提高

针对莱钢水计量系统数据传输不稳定的问题,提出改变传输方式、加装LGF智能流量仪、利于GPRS无线通信技术、实现远程网络连接、加装网络通信系统的信号防雷保护等改造措施。