An optimal multicast algorithm for cube-connected cycles

This paper presents an efficient algorithm that implements one-to-many,or multicast,communication in one-port wormhole-routed cube-connected cycles(CCCs) in the absence of hardware multicast support.By exploiting the propoeries of the switching technology and the use of virtual channels,a minimumtime multicast algorithm is presented for n-dimensional CCCs that use deterministic routing of unicast messages.The algorithm can deliver a multicast message to m-1 destinations in [log2m] message-passing steps,while avoiding contention among the constitutent unicast messages,Performance results of a simulation study on CCCs with up to 10,240 nodes are also given.     

Study of General Incomplete Star Interconnection Networks

IIntroduct1OllThe star graph【1]proposed as a particular case ofC叫ley graphs[ZJ Is vertex－and edge－symmetric．strongly hlerarchlcal,maximally tault－tolerant,strongly resilient and has diameter and node degreethat are superior to those of a slmll。－slied hypercube(which Is also a Cnyley graph)IOr parallelcomputers[3]．MNor references can be found In studying the star graph regarding its propertiesllJ,e毗edding cwabllity[4],communication c叩劝ility[5－71,andfanfaut－toierm尬 cap劝ility…     

Study of General Icomplete Star Interconnection Networks

The star networks,which were originally proposed by Akers and Harel,have suffered from a rigorous restriction on the number of nodes.The general incomplete star networks(GISN) are proposed in this paper to relieve this restriction.An efficient labeling scheme for GISN is given,and routing and broadcasting algorithms are also presented for GIS.The communication diameter of GISN is shown to be bounded by 4n-7.The proposed single node broadcasting algorithm is optimal with respect to time complexity O(nlog2n).     

钢结构筒壳局部杆件抽空与加强技术研究

在大跨空间钢结构的推广应用中,设计人员为了节省用钢量和降低结构造价,往往对结构的局部杆件进行抽空简化．着重分析了网壳的几种抽空方式的受力和变形性能,对几种抽空方式进行了综合比较,并对抽空后的加强技术提出了3种方案．     

风险定量分析中亚管道

<正>探讨风险定量分析在中亚天然气管道管理中有效运用的可行方案,建立一个为中亚天然气管道进行全面风险管理服务的定量分析体系架构,迫在眉睫。中亚天然气管道的运行安全是关系到国家能源安全、经济发展和国际政治关系的大事,影响深远。中亚天然气管道建设、运营中面临的风险错综复杂、多种多样。这些风险分布广泛,随机性强,预测难度大。如何全面监测、识别各类风险,科学精准评估分析,及时预警、有效应对,是     

基于星形互连网络的并行快速傅立叶变换算法

星形互连网络是一种易于实现大规模并行计算的互连网络拓扑结构。利用星形互连网络的递归可分解性的多样性，提出了一种基于星形互连网络的并行快速傅立叶变换算法的实现方法。该方法能够有效地减少计算过程中处理器结点之间的通信开销。提出的星图结点和数据的映射应运 及实现并行FFT的思想可推广到线性方程组求解、矩阵乘法等其它并行算法在星形互连网络上的实现。     

深圳变电站500 kV主变压器直流偏磁现象测试及抑制分析

为明确深圳变电站变压器出现间歇性噪音的成因,解决变压器噪音异常的问题,对深圳站500 kV变压器接地中性点的直流电流进行监测,通过分析表明:该变压器的噪音异常现象是由杂散电流导致的变压器直流偏磁引起。为治理变压器的直流偏磁现象,根据杂散电流入侵变压器接地中性点直流电流的特征,采用电容隔直装置对深圳站的变压器直流偏磁进行抑制;并从深圳站变压器及深圳站片区电网的角度,通过全网监测对比分析隔直装置对深圳站入侵变压器中性点直流电流的抑制效果,以及其对片区电网变压器的影响。结论表明:应根据电网的电气拓扑结构,并基于全网角度,对深圳站500 kV自耦变压器的直流偏磁进行综合优化治理。