New bivariate gamma types with MIMO application

In this paper a bivariate gamma type distribution emanating from the diagonal elements of an inverse Wishart type distribution is developed; which in turn originates from the complex matrix variate elliptical class. From this, a bivariate Weibullised gamma type distribution is also presented, of which the bivariate Nakagami-m type is a special case. The derived results may be applied as decision statistics for a MIMO (multiple input multiple output) system with two transmit antennas. It is proposed that under this elliptical umbrella some performance measures such as the outage probability of MIMO systems can be analyzed in broad generality.     

Anmerkungen zur Professionalisierung des Coaching auf dem Hintergrund des klassischen Professionsbegriffs

Some comments on the professionalization of coaching with regard to the classical concept ?profession“ In the current discussions on the professionalization of coaching the concept ?profession“ often is not clear. Therefore, the author first delineates the classical concept of profession and its main criterions. He then discusses the question whether these criterions are present in coaching and whether coaching may or should be conceived as an independent profession. Considering the tendencies of deprofessionalization in the traditional professions, it seems to be meaningful to understand coaching as a profession, but with a revised theoretical concept of profession: Particularly concerning the necessary scientific orientation it demands an interdisciplinarity instead of a fixed corpus of knowledge. The professionality of the practitioner means an orientation on general values and concepts of understanding and acting and is a central aspect of quality of coaching.     

一类存在网络外部性的水平差异模型

分析了存在网络外部性下的一个两阶段水平差异模型. 网络外部性的存在一方面提高了 消费者的购买意愿, 另一方面也加剧了厂商间的竞争. 同二次运输成本的Ho telling 模型相比, 当网络外部性不太强时, 厂商采用最大差异化原则, 但社会净福利水平得到提高; 当网络外部 性较强时, 双头垄断的市场结构不能维持, 此时垄断结构下较高的社会净福利水平是由垄断厂 商的高利润造成的.     

Performance of extrapolation based on Pitman's measure of closeness in spatial regression models with extended skew t innovations

Pitman's measure of closeness and mean square error of prediction are two well-known criteria for comparison between estimators and also between predictors. In a stationary first order multiplicative spatial autoregressive model, interpolation and extrapolation are compared based on these two criteria. A wide class of different innovation types are also studied containing Gaussian, exponential, asymmetric Laplace and extended skew t distributions.     

On the distribution of quotient of random variables conditioned to the positive quadrant

Abstract

Motivated by Caginalp and Caginalp [Physica A—Statistical Mechanics and Its Applications, 499, 2018, 457–471], we derive the exact distribution of X/Y conditioned on X?>?0, Y?>?0 for more than ten classes of distributions, including the bivariate t, bivariate Cauchy, bivariate Lomax, Arnold and Strauss’ bivariate exponential, Balakrishna and Shiji’s bivariate exponential, Mohsin et al.’s bivariate exponential, Morgenstern type bivariate exponential, bivariate gamma exponential and bivariate alpha skew normal distributions. The results can be useful in finance and other areas.     

论李达的三部著作的历史地位

李达的《现代社会学》、《社会学大纲》、《唯物辩证法大纲》三部论著,分别代表了我国从中国共产党成立到第一次大革命时期、第二次国内革命战争时期,抗日战争到解放战争时期和建国后到“文化大革命”时期马克思主义理论研究的最高水平,受到了毛泽东和理论界的赞誉和肯定。这三部论著写作的目的、开创性的研究精神、理论联系实际的治学学风,至今还是马克思主义理论研究者的不朽榜样。     

MSE performance and minimax regret significance points for a HPT estimator under a multivariate t error distribution

In this article, assuming that the error terms follow a multivariate t distribution,we derive the exact formulae forthe moments of the heterogeneous preliminary test (HPT) estimator proposed by Xu (2012b Xu, H. (2012b). MSE performance and minimax regret significance points for a HPT estimator when each individual regression coefficient is estimated. Commun. Stat. Theory Methods 42:2152–2164.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). We also execute the numerical evaluation to investigate the mean squared error (MSE) performance of the HPT estimator and compare it with those of the feasible ridge regression (FRR) estimator and the usual ordinary least squared (OLS) estimator. Further, we derive the optimal critical values of the preliminary F test for the HPT estimator, using the minimax regret function proposed by Sawa and Hiromatsu (1973 Sawa, T., Hiromatsu, T. (1973). Minimax regret significance points for a preliminary test in regression analysis. Econometrica 41:1093–1101.[Crossref], [Web of Science ®] , [Google Scholar]). Our results show that (1) the optimal significance level (α*) increases as the degrees of freedom of multivariate t distribution (ν₀) increases; (2) when ν₀ ? 10, the value of α* is close to that in the normal error case.     

The Eric Garner Case: Statewide Survey of New York Voters’ Response to Proposed Police Accountability Legislation

The Eric Garner case was unique because this police-induced death was caught on video from before the moment of physical confrontation. A mixed-methods representative household survey and Garner's arrest video were used to determine NYS voters’ opinions (n = 119) about police indictment and Governor Cuomo's request for expanded authority. Respondents were asked whether the officers should face indictment, shown the arrest video, and then asked again about indictment. Prior to the video, a majority of respondents (n = 86; 57.4%) believed involved officers should have been indicted. After viewing, the proportion increased by 13.7%. A majority supported Cuomo's call for expanded authority to appoint a special prosecutor in cases where police are involved in civilian deaths. Study limitations include prior exposure to the footage and a low response rate. NYS voters generally supported Cuomo's proposal for appointing a special prosecutor; however, a quarter of respondents disagreed with the method of reform and expressed a: 1) preference for every case to go to trial; 2) preference for a case-by-case basis; or 3) distrust in state-appointed special prosecutors. This research could inform discussions regarding proposed system reforms. Future research with a less well-circulated video is needed to determine the extent to which videos of police-induced deaths affect public opinion.     

生死悬隔的悲哀和超越幽明的幻想:悼亡赋的抒情模式及心理期待

古代悼亡赋在抒发作者的悲哀时,有的睹物思人,或写物存人亡,或写因人亡而物变;有的展示作者本身由于深哀巨痛所产生的显著变化,或迅速衰老消瘦,或精神恍惚,出现反常。悼亡赋还通过营造幻想境界,力图超越幽明界域的阻隔,在此过程中,原始宗教、文明社会的中土宗教以用佛教都渗入作品,成为心灵的慰藉。     

Local asymptotic normality for Student-Lévy processes under high-frequency sampling

There is considerable interest in parameter estimation in Lévy models. The maximum likelihood estimator is widely used because under certain conditions it enjoys asymptotic efficiency properties. The toolkit for Lévy processes is the local asymptotic normality which guarantees these conditions. Although the likelihood function is not known explicitly, we prove local asymptotic normality for the location and scale parameters of the Student-Lévy process assuming high-frequency data. In addition, we propose a numerical method to make maximum likelihood estimates feasible based on the Monte Carlo expectation-maximization algorithm. A simulation study verifies the theoretical results.