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81.
Abstract

This paper considers the statistical analysis of masked data in a parallel system with inverse Weibull distributed components under type II censoring. Based on Gamma conjugate prior, the Bayesian estimation as well as the hierarchical Bayesian estimation for the parameters and the reliability function of system are obtained by using the Bayesian theory and the hierarchical Bayesian method. Finally, Monte Carlo simulations are provided to compare the performances of the estimates under different masking probabilities and effective sample sizes.  相似文献   
82.
New series of incomplete block designs for symmetrical parallel lines are proposed. From these designs important contrasts like Lp, L1 and L1 are estimated free from block effects. In addition to these, other odd order contrasts are also estimated orthogonal to block effects. The designs are shown to have simple analysis.  相似文献   
83.
A 1024 CPU parallel computer is used to obtain simulated genotypes in the Tristan da Cunha pedigree using random local updating methods. A four-colour theorem is invoked to justify simultaneous updating. Multiple copies of the program are run simultaneously. These results are used to infer the source of the B allele of the ABO blood group that is present in the population.  相似文献   
84.
本文从曲线坐标、曲面上向量平移入手,导入了联络,继而引入协变微分、短程线及曲率张量,最后指明联络在广义相对论中的意义。  相似文献   
85.
We study minimizing communication cost in parallel algorithm design, by minimizing the number of communication phases in coarse-grained parallel computers. There have been several recent papers dealing with parallel algorithms of small communication cost under different models. Most of these results are for computational geometry problems. For these problems it has been possible to decompose tasks into appropriate subproblems in a communication-efficient way. It appears to be somewhat more difficult to design parallel algorithms with small communication phases for graph theory problems. In this paper we focus on the design of deterministic algorithms with a small number of communication phases for the list ranking problem and the shortest path problem.  相似文献   
86.
On Approximating a Scheduling Problem   总被引:4,自引:0,他引:4  
Given a set of communication tasks (best described in terms of a weighted bipartite graph where one set of nodes denotes the senders, the other set the receivers, edges are communication tasks, and the weight of an edge is the time required for transmission), we wish to minimize the total time required for the completion of all communication tasks assuming that tasks can be preempted (that is, each edge can be subdivided into many edges with weights adding up to the edge's original weight) and that preemption comes with a cost. In this paper, we first prove that one cannot approximate this problem within a factor smaller than unless P=NP. It is known that a simple approximation algorithm achieves within a ratio of two (H. Choi and S.L. Hakimi, Algorithmica, vol. 3, pp. 223–245, 1988). However, our experimental results show that its performance is worse than the originally proposed heuristic algorithm (I.S. Gopal and C.K. Wong, IEEE Transactions on Communications, vol. 33, pp. 497–501, 1985). We devise a more sophisticated algorithm, called the potential function algorithm which, on the one hand, achieves a provable approximation ratio of two, and on the other hand, shows very good experimental performance. Moreover, the way in which our more sophisticated algorithm derives from the simple one, suggests a hierarchy of algorithms, all of which have a worst-case performance at most two, but which we suspect to have increasingly better performance, both in worst case and with actual instances.  相似文献   
87.
We present efficient algorithms for local alignment search in biological sequences. These algorithms identify maximal segment pairs (MSPs). Our algorithms have the potential of performing better than BLAST (Basic Local Alignment Search Tool) and also are efficiently parallelizable. We employ Fast Fourier Transforms (FFTs). Though several attempts have been made in the past to employ FFTs in sequence analysis, they fail to capture local similarities. Our algorithms employ FFTs in a novel way to identify local similarities. FFT-based techniques have the attractive feature of benefiting from ultrafast special purpose hardware available for digital signal processing.  相似文献   
88.
词汇成分在词汇系统内部所形成的是以语言单位的共同特征为基础的聚合关系.聚合关系表现在语音、语义、语法、词汇、文字五个方面.它们以辐射状、连环状、并联状三种聚合方式聚合词汇成分,并由此形成了网络、序列、层面这样的聚合结果.这正是词汇系统的网络性、层级性、平面性的具体体现.  相似文献   
89.
哈代的作品除具有浓郁的抒情意味和感人的悲剧性之外,更以故事情节的戏剧性见长。一般说来.戏剧性必须通过矛盾冲突来实现。在《卡斯特桥市长》一书中.这些无处不在的矛盾冲突都是以巧妙的对比反衬手法设计、烘托、合理解决的。本文拟从宏现视角入手,探讨文中所揭示的某一历史瞬间和整个历史过程之间的冲突及其对主人公几经波折的悲剧命运的冲击;继之以微观视角相辅.从情节的跌宕起伏.人物关系的错综复杂方面浅析对比反衬手法在本书中淋漓尽致的运用。  相似文献   
90.
在数字复合正交神经网络(NN)的基础上提出一种模拟复合正交神经网络,并用于轴向磁轴承的控制中.控制器采用模拟复合正交神经网络与PID的并行控制方法,对带有负载干扰的轴向磁轴承控制系统作了PID控制与NN PID控制的仿真实验.仿真结果表明,相对于常规PID控制器,该并行控制法具有非常好的抗干扰与自适应能力,获得了满意的控制效果.  相似文献   
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