多维数据流最大频集挖掘模型和算法

为了挖掘到有价值的信息,需要挖掘多维数据流上的频繁项目集,因此引入多维项目和多维项目集的概念表示多维数据流上的项目.设计了一种紧凑、压缩的数据结构MaxFP-Tree用于维护多维项目集,并在MaxFP-Tree的基础上设计了挖掘多维数据流上最大频集的增量式更新算法.实验结果表明,设计的挖掘多维数据流中最大频集的模型和算法是高效的.     

数据流中基于滑动窗口的最大频繁项集挖掘算法*

挖掘数据流中最大频繁项集是从数据流中获得信息的一种有效手段,是数据流挖掘研究的热点之一。结合数据流的特点,提出了一种新的基于滑动窗口的最大频繁项集挖掘算法。该算法用位图来存储数据流中流动的数据;采用直接覆盖的方法存储和更新数据流上的数据;在深度优先搜索挖掘最大频繁项集时,除采用经典的剪枝策略外,还提出了与父等价原理相对应的子等价剪枝策略;最后将挖掘结果存储在索引链表中以提高超集检测效率,进一步减少挖掘最大频繁项集的时间。理论分析和实验结果证实了该算法在时间和空间上的有效性。     

基于滑动窗口的数据流中近期频繁项挖掘

提出了一种在单独数据流中挖掘近期频繁项的算法MRFI。该算法采用基于对时间敏感的滑动窗口的模式,保证了挖掘结果的时效性,并利用循环队列和二叉排序树实现了简单高效的数据存储和处理,该方法是一种近似算法,它可以消除历史数据对挖掘结果的影响。实验采用IBM数据发生器产生合成数据,证明了该算法的有效性。     

移动WiMAX网络中跨层快速切换的研究*

针对移动WiMAX网络中,基于FMIPv6和DAD (duplicate address detection)机制的快速切换存在着开销大和检测时延长的问题,提出了一种跨层快速切换的策略。新策略在FMIPv6基础上,使用了mSCTP协议和ODAD (optimistic DAD)机制,成功地消除了FMIPv6协议中建立隧道的开销和减少了DAD地址检测的时延。仿真结果显示,新的切换策略将切换时延和分组丢失分别降低了65%和60%。     

基于JMF的音视频会议系统的研究与实现

介绍了Java媒体框架应用编程接口（JMF）的结构特点及其实时传输协议（RTP）支持,实现了端对端的实时音视频网络会议系统.文中阐述了小型多人视频会议系统的工作原理以及RTP传输、数据源复用等关键技术问题,最后重点描述了基于JMF的音视频会议系统的设计方案,并详细介绍了系统软件的具体实现.     

瓮福磷矿选矿厂精矿仓设计

瓮福磷矿选矿厂精矿仓首次采用网架式地面矿仓，造价低，空间利用率高，设备运行平稳可靠，操作灵活方便，工作环境好。超长梭式胶带布料机的设计也是成功的。     

EVALUATION OF SURFACE FORCE-PORE FLOW AND MODIFIED SURFACE FORCE-PORE FLOW MODELS FOR REVERSE OSMOSIS TRANSPORT

The surface force-pore flow (SF-PF) model of reverse osmosis transport and the extended and modified form (the MD-SF-PF model) have been employed to predict the performance of four aromatic polyamide (FilmTec, FT30)reverse osmosis membranes. The evaluation is based on a comparison of model predictions with experimental data. Dilute sodium chloride-water solution experimental data were used to estimate model parameters. The models are then used to predict flux and separation at various operating pressures and concentrations. Membrane performance (i.e., separation and permeate flux) can be well predicted by the MD-SF-PF model while the SF-PF model predicts the performance for the sodium chloride system less satisfactorily.     

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。     

Characterization and modeling of diffusion process for mass transport through the Tournemire argillites (Aveyron, France)

Argillites are one of the geological formations studied by IRSN for their confining properties for isolation of radioactive wastes. One of the main objectives is the study of water transport through rocks with very low water content and very low hydraulic conductivity by modeling of natural tracer profiles. This paper presents the protocol developed for and applied to the acquisition of data for chloride content in interstitial water of the Toarcian argillites at the Tournemire site (Southern France). This protocol is based on laboratory diffusion experiments and on modeling. Experimental data obtained during the transient and steady-state parts of diffusion experiments enable, respectively, the assessment of the diffusion coefficient and the determination of Cl concentration in pore water. Using this protocol, profiles with depth for both of these data sets have been acquired along the geological sequence. Taking into account the present knowledge of the geological and hydrogeological history of the Tournemire massif, a conceptual model granting the main role for mass transport to diffusion has been proposed. According to this conceptual model, a one-dimensional numerical model was built for simulating the mass transport of chloride through the sedimentary column, over 53 Ma. The good agreement between experimental data and calculated values for both diffusion coefficients and concentrations of chloride confirms that diffusion is likely the main process for mass transport in the massif. This model was also tested with the deuterium content of interstitial water, applying variable concentrations at the aquifer system boundaries for reflecting the thermal dependency of isotopic composition in precipitation. These simulations also reveal the likely important role of heterogeneities, such as fractures, in the variability of tracer concentrations with regards to a simple diffusion profile.     

面向上行流媒体的压缩感知视频流技术前沿

上行流媒体在军民融合领域展现出日益重要的新兴战略价值,压缩感知视频流技术体系在上行流媒体应用中具有前端功耗低、容错性好、适用信号广等独特优势,已成为当前可视通信研究的前沿与热点之一。本文从阐述上行流媒体的应用特征出发,从性能指标、并行分块计算成像、低复杂度视频编码、视频重构和语义质量评价等方面,分析了当前针对压缩感知视频流的基础理论与关键技术,对国内外相关的研究进展进行了探究与比较。面向上行流媒体的压缩感知视频流面临着观测效率难控、码流适配困难和重建质量较低等技术挑战。对压缩感知视频流的技术发展趋势进行展望,未来将通过前端与智能云端的分工协作,突破高效率的视频观测与语义质量导引视频重构等关键技术,进一步开拓压缩感知视频流在上行流媒体应用中的定量优势与演进途径。