用K-means聚类分析进行储层分类

对于储层进行分类时,由于地质参数比较多,常常给分类带来很多困难。本文介绍的聚类方法,能够实现储层分类,并通过实例介绍了该方法的应用,具有积极意义。     

基于节点位置和剩余能量的分簇路由改进算法

针对传统LEACH协议存在的随机选举簇头及网内节点能耗不均等问题,提出了一种能量均衡高效的分簇路由协议LEACH-EPN.在成簇阶段加入最优簇数约束,综合考虑节点位置和剩余能量等多种因素;引入距离因子、能量因子及节点密度因子改进阈值公式;通过改变簇的范围来改变成簇机制,使簇头选举更合理、能耗分布更均匀,提高了网络的能量...     

Climate classifications and building energy use implications in China

Cluster analysis of summer and winter discomfort in terms of heat and cold stresses based on 102-year (1901-2002) weather data in China was conducted. Five bioclimate zones were identified. These were compared with the corresponding thermal and solar zoning classifications. Bio-I and Bio-II tended to locate largely within severe cold and cold climates in the north with excellent solar availability (annual clearness index K_t generally exceeding 0.5). Bio-III and Bio-IV covered mostly the hot summer and cold winter and mild climate zones. Despite the relatively low K_t in winter, passive solar heating should be able to meet a significant proportion of the heating requirements. Bio-V covered the hot summer and warmer winter region, where heat stress and hence cooling requirement dominated. Decreasing trends in the zone-average annual cumulative cold stress during the 102-year period were observed for all five zones. There was, however, no distinct pattern for the heat stress and the changes tended to be more subtle. These indicate that climate change during the 20^th century affected winter discomfort (especially in colder climates in the north) more than the summer discomfort. This could have significant implications for energy use in buildings if such trends persist.     

HACMP双机热备份集群系统

双机热备份方式是一种软硬件结合的高可靠性应用模式,它解决了单一故障点的问题,使得整个应用系统能继续工作。     

基于胶束电动色谱法区分绿茶的研究

基于胶束电动色谱法建立不同种类绿茶的分类方法。色谱条件是:75 μm×57cm(有效长度50 cm)未涂层熔融石英毛细管,电解质为20 mM磷酸盐含20 mM十二烷基硫酸钠(SDS)的溶液(pH 7.0),分离电压20 kV,温度25℃,0.5 psi压力进样5 s,检测波长210 nm。此法可同时检测5种儿茶素组分,以5种儿茶素的含量为指标,采用聚类分析法对不同绿茶分类,结果:不同种类的绿茶具有明显差异,该研究可为绿茶品质鉴定提供一种合理、准确、可靠的方法。     

布局问题的聚块算法

聚块布局法是解决布局问题的方法之一。本文对聚块布局法的关键点－聚块函数和模块组合进行了研究并提出了聚块算法，从而为模块组合和模块内布局物体位置的确定提供了一个定量的评价依据。     

Fusion neutron detector calibration using a table-top laser generated plasma neutron source

Using a high intensity, femtosecond laser driven neutron source, a high-sensitivity neutron detector was calibrated. This detector is designed for observing fusion neutrons at the Z accelerator in Sandia National Laboratories. Nuclear fusion from laser driven deuterium cluster explosions was used to generate a clean source of nearly monoenergetic 2.45 MeV neutrons at a well-defined time. This source can run at 10 Hz and was used to build up a clean pulse-height spectrum on scintillating neutron detectors giving a very accurate calibration for neutron yields at 2.45 MeV.     

数字卫星直播的特点

介绍数字卫星直播的特点与组成,并与其他传输方式比较其性能优势.     

A Tree-Based Data Collecting Network Structure for Wireless Sensor Networks

In a sensor network with a large numberof densely populated sensor nodes, a single target ofinterest may be detected by multiple sensor nodessimultaneously. Data collected from the sensor nodes areusually highly correlated, and hence energy saving usingin-network data fusion becomes possible. A traditionaldata fusion scheme starts with dividing the network intoclusters, followed by electing a sensor node as clusterhead in each cluster. A cluster head is responsible forcollecting data from all its cluster members, performingdata fusion on these data and transmitting the fused datato the base station. Assuming that a sensor node is onlycapable of handling a single node-to-node transmissionat a time and each transmission takes T time-slots, acluster head with n cluster members will take at least nTtime-slots to collect data from all its cluster members. Inthis paper, a tree-based network structure and itsformation algorithms are proposed. Simulation resultsshow that the proposed network structure can greatlyreduce the delay in data collection.