A multivariate solution of the multivariate ranking and selection problem

The problem of selection of the best multivariate population is given a new formulation which does not involve reducing the populations to univariate quantities. This formulation's solution is developed for known, and (using the Heteroscedastic Method) also for unknown, variance-covariance matrices. Preference reversals and arbitrary nonlinear preference functions are explicitly allowed in this new theory     

Testing the equality of several covariance matrices

Using a new approach based on Meijer G-functions and computer simulation, we numerically compute the exact null distribution of the modified-likelihood ratio statistic used to test the hypothesis that several covariances matrices of normal distributions are equal. Small samples of different sizes are considered, and for the case of two matrices, we introduce a new test based on determinants, with the null distribution of its criterion also fully computable. Comparisons with published results show the accuracy of our approach, which is proved to be more flexible and adaptable to different cases.     

新颖的Chirp通信系统同步方法

提出的同步方法把Chirp信号扫频频率范围和扫频时间都扩展了一倍的本地信号与接收信号相乘,并利用乘积信号中主要频率分量的强度来构成反馈环路,再通过该反馈环路来对输入信号的延迟进行跟踪和锁定。分析和仿真结果表明,该方法可以完成系统的时间同步任务。该方法的核心在于把本地参考信号的扫频频率范围和扫频时间进行了扩展,从而排除了常用方法在宽带、超宽带情况下受信道影响的问题,同时由于避免了使用滑动相关器,也因此降低了复杂度。     

基于有效预测区域的模糊数据关联

多目标多传感器跟踪系统由数据关联和目标状态估计两部分组成,数据关联是多目标跟踪系统研究的核心。数据关联和目标状态估计两部分既有一定的独立性又有密切的联系,而将两部分合理地结合对提高跟踪系统的性能是重要的。该文以跟踪目标的有效预测区域为依据,利用基于Mahalanobis距离的模糊均值聚类方法解决数据关联问题,在一定程度上将数据关联和目标状态估计两个不同的过程相结合,仿真计算说明了其有效性。     

Time series count data regression

The count data model studied in the paper extends the Poisson model by al-lowing for overdispersion and serial correlation. Alternative approaches to esti-mate nuisance parameters, required for the correction of the Poisson maximum likelihood covariance matrix estimator and for a quasi-likelihood estimator, are studied. The estimators are evaluated by finite sample Monte Carlo experi-mentation. It is found that the Poisson maximum likelihood estimator with corrected covariance matrix estimators provide reliable inferences for longer time series. Overdispersion test statistics are wellbehaved, while conventional portmanteau statistics for white noise have too large sizes. Two empirical illustrations are included.     

On a paper by kageyama and mohan

Kageyama Mohan (1984) have presented three methods of constructing new incomplete block designs from balanced incomplete block designs, They raise questions about the designs which come from each of their methods, These questions are answered, Another series of group divisible designs is derived as a special case of their second method.     

Problem Solving is Often a Matter of Cooking Up an Appropriate Markov Chain*

Abstract. By means of a series of examples, from classic contributions to probability theory as well as the author's own, an attempt is made to convince the reader that problem solving is often a matter of cooking up an appropriate Markov chain. Topics touched upon along the way include coupling, correlation inequalities, and percolation.     

自然垄断产业规制的国际比较研究

从自然垄断产业规制理论出发 ,根据国际上各国对自然垄断产业放松规制的实践 ,分析了放松规制的理论依据 ,并通过对中外自然垄断产业规制的比较研究 ,提出了中国自然垄断产业改革中应解决的主要问题 :制定相关法律 ,组建新型的保持利益中性的规制机构 ,合理分割原有自然垄断型企业 ,引入竞争机制 ,构建激励性规制改革的微观企业制度基础。     

公益广告的攻心策略

公益广告的效果研究一直处于广告研究的滞后阶段。目前的公益广告存在着“隔岸观火”和“隔靴搔痒”两大病症。问题的关键是广告诉求与受众的相关度不高。对症下药,提高公益广告效果的策略有三:真实再现、指向明确和对比联想。