Regularization through variable selection and conditional MLE with application to classification in high dimensions

It is often the case that high-dimensional data consist of only a few informative components. Standard statistical modeling and estimation in such a situation is prone to inaccuracies due to overfitting, unless regularization methods are practiced. In the context of classification, we propose a class of regularization methods through shrinkage estimators. The shrinkage is based on variable selection coupled with conditional maximum likelihood. Using Stein's unbiased estimator of the risk, we derive an estimator for the optimal shrinkage method within a certain class. A comparison of the optimal shrinkage methods in a classification context, with the optimal shrinkage method when estimating a mean vector under a squared loss, is given. The latter problem is extensively studied, but it seems that the results of those studies are not completely relevant for classification. We demonstrate and examine our method on simulated data and compare it to feature annealed independence rule and Fisher's rule.     

A new nonparametric bivariate test for two sample location problem

A strictly nonparametric bivariate test for two sample location problem is proposed. The proposed test is easy to apply and does not require the stringent condition of affine-symmetry or elliptical symmetry which is required by some of the major tests available for the same problem. The power function of the proposed test is calculated. The asymptotic distribution of the proposed test statistic is found to be normal. The power of proposed test is compared with some of the well-known tests under various distributions using Monte Carlo simulation technique. The power study shows that the proposed test statistic performs better than most of the test statistics for almost all the distributions considered here. As soon as the underlying population structure deviates from normality, the ability of the proposed test statistic to detect the smallest shift in location increases as compared to its competitors. The application of the test is shown by using a data set.     

Efficient Use of Two Decks of Cards in Randomized Response Sampling

This paper extends the work of Russell (1976). Proof Is given that, for many parameter sets, all O:XB designs belonging to the set are connected. It is shown how an (M,S)-optinal design nay be selected from the M-optimal designs of a given parameter set. The efficiencies of these (M,S)-optimal designs are displayed, and it is concluded that the (M,S)-optimality criterion is useful for selecting designs of high efficiency.     

Tests for Equality of Parameters of Two Exponential Distributions with Common Known Coefficient of Variation

ABSTRACT

This article considers the problem of testing equality of parameters of two exponential distributions having common known coefficient of variation, both under unconditional and conditional setup. Unconditional tests based on BLUE'S and LRT are considered. Using the Conditionality Principle of Fisher, an UMP conditional test for one-sided alternative is derived by conditioning on an ancillary. This test is seen to be uniformly more powerful than unconditional tests in certain given ranges of ancillary. Simulation studies on the power functions of the tests are done for this purpose.     

试论金代的桑税

金代桑税渊源于辽和北宋的桑税制度.金代在继承辽宋桑税制度的同时,也进一步发展了自己的桑税制度.这表现为:一方面金代两税中的全部税绢都依据桑税征收,从而提高了它在两税中的地位;另一方面金代确立了旨在规定民户最低桑税额的桑地制度.金代桑税并非"户调",而是金代土地税的基本内容,也是金代两税的重要组成部分.     

Explicating trust and its relation to dialogue at a time of divided societies

Values, beliefs, opinions and attitudes on issues (such as religion, LGBTQ, immigration, etc.), and the proliferation of social media platforms have made society not only more diverse but also more divided. Competing and conflicting views and attitudes result in more schisms and disengagement. In addition, conflicts and disagreements on various issues also have resulted in a lack of trust and a reluctance of organizations and publics to engage in meaningful communication. As a result, developing trusting relationships by facilitating dialogues is significant. Trust has been an important construct in past research on organization-public relationships. However, the concept of trust has rarely been discussed in-depth in public relations literature. This special section of Public Relations Review, entitled Enhancing Dialogue and Trust in Diverse Societies, examines whether the current definitions of trust and its dimensions in the public relations literature are adequate in an organization-public dialogic communication setting.     

重审教育现代化进程中的人文向度

作为外力冲击下的被动型现代化,中国教育现代化进程带有明显的追赶心态,失却了本土文化自觉,承载着过重的外在功利负荷。重温本土意义上的教育现代化探索之路,审视教育本体并聚焦人的健康成长,探寻科学教育与人文教育的辩证关系,有助于理性反思教育现代化进程中的人文向度,以期为当代教育改革提供必要的历史借鉴。     

Price Incentives and Coordination in a Two‐Product Decentralized Supply Chain

We investigate pricing incentives for competing retailers who distribute two variants of a manufacturer's product in a decentralized supply chain. Under a two‐dimensional Hotelling model, we derive decentralized retailers' prices for the products, and distortions in pricing when compared to centrally optimal prices. We show that price distortions decrease as consumers' travel cost between retailers increases, due to less intense competition. However, price distortions do not change monotonically in consumers' switching cost between products within stores. To fix decentralized retailers' price distortions, we construct a two‐part pricing contract that coordinates the supply chain. We show that the coordinating contract is Pareto‐improving and analyze increase in the supply chain profit under coordination.     

电力企业上市公司基本面综合评价

本文采用主成分分析的方法,以上海股市25家电力企业上市公司2004年中报公布的财务报告为基础,以95%的精度用2个新指标来代替原来的11个财务指标对这25家上市公司进行综合评价,同时在主成分分析的基础上对25家电力上市公司进行了综合评价和比较。