不适定线性算子方程的最佳逼近解的特征

设X,Y为Banach空间,T为从X到Y的线性算子,在算子T的值域的闭包R(T)((∝)Y且≠Y)为Y中逼近紧子空间,T的定义域D(T)不一定为全空间X的条件下,给出了不适定算子方程Tx=y的最佳逼近解对任意y∈Y均存在的一个特征是T的零空间N(T)为D(T)的存在性子空间,推广和改进了黄永辉、曲绍平和王玉文于2008年所给出的结果.     

A powerful test for multivariate normality

This paper investigates a new test for normality that is easy for biomedical researchers to understand and easy to implement in all dimensions. In terms of power comparison against a broad range of alternatives, the new test outperforms the best known competitors in the literature as demonstrated by simulation results. In addition, the proposed test is illustrated using data from real biomedical studies.     

Weighted Logrank Permutation Tests for Randomly Right Censored Life Science Data

In biomedical research, weighted logrank tests are frequently applied to compare two samples of randomly right censored survival times. We address the question how to combine a number of weighted logrank statistics to achieve good power of the corresponding survival test for a whole linear space or cone of alternatives, which are given by hazard rates. This leads to a new class of semiparametric projection tests that are motivated by likelihood ratio tests for an asymptotic model. We show that these tests can be carried out as permutation tests and discuss their asymptotic properties. A simulation study together with the analysis of a classical data set illustrates the advantages.     

基于交互密度算子的交互式群体评价信息集结方法及其应用

交互式群体评价的一个难点问题是评价信息的集结问题,而国内较少有文献从信息集结算子的角度进行探讨,针对这种不足,同时考虑到信息分布密度是交互式群体评价信息集结的一个重要特征,本文提出了一种基于交互密度算子的交互式群体评价信息集结方法。提出了交互密度算术加权算子(IDWA)与交互密度几何加权算子(IDWGA)两种新的算子,并对新算子的相关性质进行了分析,同时介绍了IDWA和IDWGA算子加权向量(即密度权向量)的确定方法。最后将该方法进行了运用。文章对交互式评价信息集结问题提供了一种新的研究思路。     

Properties of design-based functional principal components analysis

This work aims at performing functional principal components analysis (FPCA) with Horvitz–Thompson estimators when the observations are curves collected with survey sampling techniques. One important motivation for this study is that FPCA is a dimension reduction tool which is the first step to develop model-assisted approaches that can take auxiliary information into account. FPCA relies on the estimation of the eigenelements of the covariance operator which can be seen as nonlinear functionals. Adapting to our functional context the linearization technique based on the influence function developed by Deville [1999. Variance estimation for complex statistics and estimators: linearization and residual techniques. Survey Methodology 25, 193–203], we prove that these estimators are asymptotically design unbiased and consistent. Under mild assumptions, asymptotic variances are derived for the FPCA’ estimators and consistent estimators of them are proposed. Our approach is illustrated with a simulation study and we check the good properties of the proposed estimators of the eigenelements as well as their variance estimators obtained with the linearization approach.     

一种新的梯形模糊数互补判断矩阵的排序方法

研究了决策信息以梯形模糊数互补判断矩阵形式给出的有限方案决策问题。首先利用COWA算子,引入期望值函数概念对梯形模糊数来排序,排序结果可以根据决策者的乐观程度进行调节,更加合理。然后基于期望值函数,把梯形模糊数互补判断矩阵转化期望值互补判断矩阵进行排序,并利用决策者的乐观程度对排序结果进行敏感性分析。最后通过算例说明了该方法的可行性和有效性。     

游戏运营平台定价模型及价格影响因素分析

本文利用双边市场理论对游戏运营平台的定价模型及影响因素进行了相关研究,并指出,游戏运营平台具有典型的双边市场特征,表现出明显的正网络外部性。文章通过建立垄断和竞争两种情况下的定价模型研究了游戏运营平台的定价问题,并通过分析得出游戏开发商和玩家的需求价格弹性、一边用户对另一边用户的网络外部性大小、游戏运营市场的竞争程度、游戏运营平台向双边提供产品或服务的成本以及竞争性运营平台间提供产品或服务的差异化程度是影响游戏运营平台定价的主要因素。     

基因表达式编程种群多样性自适应调控算法

为了解决基因表达式编程GEP种群多样性控制问题,提出了一种新的带权种群多样性的自适应调控方法。设计了带权的种群多样性测度方法,详细分析了选择、交叉及变异算子对种群多样性的影响。提出了初始种群的多样化算法DAIP,以保证初始种群多样性的最大化。设计了自适应的交叉和变异算子,提出了种群多样性自适应调控算法APDTA,使种群在进化过程中维持合适的种群多样性,进而提高进化效率。实验验证了APDTA的有效性。     

一种新的最短路径算法

定义了有向图的代价邻接矩阵和最短路径矩阵,给出了称为“乘位加比小”的一种代价邻接矩阵间的新运算。基于该矩阵运算,证明了一种称为“代价邻接矩阵乘位加比小算法”新的最短路径算法。其结果可实现有向图全局最短寻径,并且对于任意类型的有向图,总是可准确求得其最短路径。E.W.Dijkstra提出的标号法是一种公认的求最短路径的较好算法,但在某些情况下寻径结果并非最优,文中提出的新算法克服了其缺点。     

逆算符方法求解非线性方程简介

本文首先简单介绍了逆算符理论，然后用该方法求解了强非线性ＲＬＣ电路方程，从而表明逆算符方法与计算机结合在非线性物理中有广泛的应用前景。