Von Mises分布在陕西省保费收入中的应用

保费收入的季节波动对保险业的增长具有重要的影响。应用方向数据统计对2005~2009年陕西省保费收入进行了季节波动分析,通过假设检验及统计推断得出陕西省保费收入服从双峰Von Mises分布,具有明显的季节波动性。     

面向时滞测试生成的改进遗传算法(英文)

在提出的无冒险的时滞测试能量函数的基础上,对传统的遗传算法进行了改进,即在搜索中根据进化程度对群体尺寸进行调整来加速收敛,用于时滞测试生成。实验证明该方法是一种较有发展前途的算法。     

A modified economic-statistical design of the T2 control chart with variable sample sizes and control limits

Recent studies have shown that using variable sampling size and control limits (VSSC) schemes result in charts with more statistical power than variable sampling size (VSS) when detecting small to moderate shifts in the process mean vector. This paper presents an economic-statistical design (ESD) of the VSSC T² control chart using the general model of Lorenzen and Vance [22]. The genetic algorithm approach is then employed to search for the optimal values of the six test parameters of the chart. We then compare the expected cost per unit of time of the optimally designed VSSC chart with optimally designed VSS and FRS (fixed ratio sampling) T² charts as well as MEWMA charts.     

A predictive approach to measuring the strength of statistical evidence for single and multiple comparisons

The normalized maximum likelihood (NML) is a recent penalized likelihood that has properties that justify defining the amount of discrimination information (DI) in the data supporting an alternative hypothesis over a null hypothesis as the logarithm of an NML ratio, namely, the alternative hypothesis NML divided by the null hypothesis NML. The resulting DI, like the Bayes factor but unlike the P‐value, measures the strength of evidence for an alternative hypothesis over a null hypothesis such that the probability of misleading evidence vanishes asymptotically under weak regularity conditions and such that evidence can support a simple null hypothesis. Instead of requiring a prior distribution, the DI satisfies a worst‐case minimax prediction criterion. Replacing a (possibly pseudo‐) likelihood function with its weighted counterpart extends the scope of the DI to models for which the unweighted NML is undefined. The likelihood weights leverage side information, either in data associated with comparisons other than the comparison at hand or in the parameter value of a simple null hypothesis. Two case studies, one involving multiple populations and the other involving multiple biological features, indicate that the DI is robust to the type of side information used when that information is assigned the weight of a single observation. Such robustness suggests that very little adjustment for multiple comparisons is warranted if the sample size is at least moderate. The Canadian Journal of Statistics 39: 610–631; 2011. © 2011 Statistical Society of Canada     

基于遗传算法的神经网络港口投资辅助决策

尝试用遗传算法与神经网络结合,对港口投资的可行性进行衡量,并建立了相应的投资决策模型,结合实例计算分析得到满意的结果。该方法有效地解决了传统BP算法对多峰值问题存在收敛于局部非劣解的弊病,而且大大加快了收敛的速度。     

基于遗传算法的机组优化组合的应用研究

火电厂机组优化组合问题是一个复杂的优化问题,本文提出了用于求解机组优化组合的一种改进的遗传算法方法,取得了较好的计算结果。     

Minimax powerful functional analysis of covariance tests with application to longitudinal genome-wide association studies

We model the Alzheimer's disease-related phenotype response variables observed on irregular time points in longitudinal Genome-Wide Association Studies as sparse functional data and propose nonparametric test procedures to detect functional genotype effects while controlling the confounding effects of environmental covariates. Our new functional analysis of covariance tests are based on a seemingly unrelated kernel smoother, which takes into account the within-subject temporal correlations, and thus enjoy improved power over existing functional tests. We show that the proposed test combined with a uniformly consistent nonparametric covariance function estimator enjoys the Wilks phenomenon and is minimax most powerful. Data used in the preparation of this article were obtained from the Alzheimer's Disease Neuroimaging Initiative database, where an application of the proposed test lead to the discovery of new genes that may be related to Alzheimer's disease.     

互动式测试:英语口试的新模式

英语口试是考查受试者运用英语作为一种交流思想的口头工具的效率和效果,根据现代语言测试的理论,信度和效度正是科学的语言测试的两个根本要求。然而,现行的英语口试在信度和效度上都存在问题,不能有效而准确地检测考生的实际语言运用能力。因此,尝试构建一种可行的互动式口语测试模式,使之真正成为一种能衡量考生实际口语水平的测试手段,并对英语教学起到良好的、积极的反拨作用。     

语言测试的效度本质观

对效度本质的不同认识,导致了不同的效度理论,产生了不同的效度验证实践.实证主义效度本质观强调相关关系和因果关系,注重确定性和普遍性.自然主义效度本质观强调研究结果和研究的其他部分之间的一致性,注重主体间不断互动的活动和过程.效度理论和效度验证实践研究中存在的争议主要有:效度与信度、效度的整体性与可分性、效度与效度验证等.在探讨实证主义和自然主义研究方法以及应用于语言教学研究的理论和实践时,应该尽力弄清潜在的研究假设,应该意识到确定研究证据的依据的不同.     

电子科技大学计算电磁学实验室对计算电磁学的研究进展(英文)

介绍了电子科技大学计算电磁学实验室近年来在计算电磁学领域取得的一些进展和成果。在数值计算方法方面,针对传输、辐射和散射问题,提出了一些新的和改进的时域数值方法和频域数值方法,在保证计算精度的同时提高了仿真的计算效率。在电磁建模方面,提出了知识人工神经网络方法和新型传输线方法,作为高效的CAD工具,其能实现准确和快速的电磁建模。在电磁优化方面,采用跳跃基因遗传算法和空间映射方法对天线和微波无源器件进行了高效率的优化。