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141.
Improvement in inter-cell spectrum efficiency is a valuable research topic in mobile communication system, which affects cell edge user experience especially. According to current research results, there are three methods to deal with inter-cell interference to improve inter-cell spectrum efficiency, including inter-cell interference randomization, inter-cell interference cancellation and inter-cell interference coordination. This paper analyzes three important inter-cell spectrum efficiency improvement technologies, soft frequency reuse (SFR), uplink power control, and downlink coordinated multi-point transmission/reception (CoMP), and relative research progress. 相似文献
142.
M. Mohsenzadeh S. Rouhani M. V. Takook 《International Journal of Theoretical Physics》2009,48(3):755-762
The power spectrum of scalar field and space-time metric perturbations produced in the process of inflation of universe, have
been presented in this paper by an alternative approach to field quantization namely, Krein space quantization (Gazeau et
al. in Class. Quantum Gravity 17:1415, 2000; Takook in Int. J. Mod. Phys. E 11:509, 2002; Rouhani and Takook in ). Auxiliary negative norm states, the modes of which do not interact with the physical world, have been utilized in this
method. Presence of negative norm states play the role of an automatic renormalization device for the theory. 相似文献
143.
We present a new method for estimating the frontier of a sample. The estimator is based on a local polynomial regression on the power-transformed data. We assume that the exponent of the transformation goes to infinity while the bandwidth goes to zero. We give conditions on these two parameters for obtaining almost complete convergence. The asymptotic conditional bias and variance of the estimator are provided and its good performance is illustrated for some finite sample situations. 相似文献
144.
The universal occurrence of a hierarchical structure and its dynamic behavior in various types of group, living or abstract, are discussed. Here the word “group” refers not only to tangible aggregation but also to invisible aggregation of social psychological and of geopolitical meaning. The evolution of these groups is simulated using a model of agents distributed on the lattices of cellular grids. It is assumed that agents, fearing isolation, interact asymmetrically with each other with regard to exchange of “power”. As an indicator of hierarchy, the Gini coefficient is introduced. Example calculations are made for the aggregation, fusion and fission of animal groups, and for the appearance of a powerful empire and the rise and fall of supremacy. It is shown that such abstract objects evolve with time in accordance with the universal rules of groups common to birds and fish. 相似文献
145.
146.
Nariaki Sugiura Hidetoshi Murakami Seong Keon Lee Yasutomo Maeda 《Annals of the Institute of Statistical Mathematics》2006,58(1):93-100
This paper answers the long-standing question of whether the two-sided Wilcoxon rank test for equal sample sizes is unbiased
against a location parameter family of distributions by giving a counterexample. It is also shown that the nonrandomized two-sided
Wilcoxon test for equal sample sizes with the least positive significance level is unbiased. 相似文献
147.
尽管金融学理论认为股票的价值是未来无限期预期现金流的一个贴现,但针对国际股市的实证结果显示,股票实际价格很大程度上取决于市场对其未来一两年内的盈利预期等中期基本面因素.近3年里,A股创造的世界罕见的大起大落,引起了社会各界对A股定价是否合理的广泛争论.为此,我们设计了一个相对估值模型,根据国际股市的定价规则来给A股定价.实证结果显示,A股已经从2007年的估值泡沫回落到2008年的合理估值水平.还可以经过进一步地扩展模型讨论单个股票的定价问题.最后,讨论了实证结果的引申含义和一些政策建议. 相似文献
148.
王平平 《数学的实践与认识》2007,37(7):7-10
通过建立一个博弈模型,研究在不确定性条件下,市场特征和市场信息对企业利润的影响.在一定条件下,预测越精确,信息越有价值;而在其他情况下则相反.产品替代程度越高,或市场预期需求越大,都将对企业利润产生积极影响. 相似文献
149.
基于误差理论的区间主成分分析及其应用 总被引:1,自引:0,他引:1
针对区间数样本,传统的主成分分析需进行拓展。首先讨论了区间样本数据的两种主要来源,即观测误差和符号数据分析。然后将区间数看作一个由中点和半径构成的具有一定误差的数,从误差理论出发,研究基于误差传递公式的区间主成分分析方法,并获得以区间数为表达形式的主成分。最后,结合我国2005年第四季度股票市场的数据进行了实证分析。结果表明,面对海量数据,区间PCA较传统PCA更容易从总体上把握样本的属性。 相似文献
150.
Petr Ya. Ekel Marden Menezes Fernando H. Schuffner Neto 《Nonlinear Analysis: Hybrid Systems》2007,1(4):527-536
This paper presents results of research into the use of the Bellman–Zadeh approach to decision making in a fuzzy environment for solving multicriteria optimization problems. Its application conforms to the principle of guaranteed result and provides constructive lines in obtaining harmonious solutions on the basis of analyzing associated maxmin problems. The use of the Bellman–Zadeh approach has served as a basis for solving a problem of multicriteria allocation of resources (or their shortages) and developing a corresponding adaptive interactive decision making system (AIDMS1). AIDMS1 includes procedures for considering linguistic variables to reflect conditions that are difficult to formalize as well as procedures for constructing and correcting vectors of importance factors for goals. The use of these procedures permits one to realize an adaptive approach to processing information of a decision maker to provide successive improvment in solution quality. The results of the paper are universally applicable and are already being used to solve power engineering problems. It is illustrated by considering problems of multicriteria power and energy shortage allocation and multicriteria power system operation. 相似文献