Sparse Bayesian variable selection in multinomial probit regression model with application to high-dimensional data classification

Here we consider a multinomial probit regression model where the number of variables substantially exceeds the sample size and only a subset of the available variables is associated with the response. Thus selecting a small number of relevant variables for classification has received a great deal of attention. Generally when the number of variables is substantial, sparsity-enforcing priors for the regression coefficients are called for on grounds of predictive generalization and computational ease. In this paper, we propose a sparse Bayesian variable selection method in multinomial probit regression model for multi-class classification. The performance of our proposed method is demonstrated with one simulated data and three well-known gene expression profiling data: breast cancer data, leukemia data, and small round blue-cell tumors. The results show that compared with other methods, our method is able to select the relevant variables and can obtain competitive classification accuracy with a small subset of relevant genes.     

Bivariate extension of (dynamic) cumulative past entropy

Recently, the concept of cumulative residual entropy (CRE) has been studied by many researchers in higher dimensions. In this article, we extend the definition of (dynamic) cumulative past entropy (DCPE), a dual measure of (dynamic) CRE, to bivariate setup and obtain some of its properties including bounds. We also look into the problem of extending DCPE for conditionally specified models. Several properties, including monotonicity, and bounds of DCPE are obtained for conditional distributions. It is shown that the proposed measure uniquely determines the distribution function. Moreover, we also propose a stochastic order based on this measure.     

On extreme order statistics from heterogeneous beta distributions with applications

This paper treats the problem of stochastic comparisons for the extreme order statistics arising from heterogeneous beta distributions. Some sufficient conditions involved in majorization-type partial orders are provided for comparing the extreme order statistics in the sense of various magnitude orderings including the likelihood ratio order, the reversed hazard rate order, the usual stochastic order, and the usual multivariate stochastic order. The results established here strengthen and extend those including Kochar and Xu (2007 Kochar, S.C., Xu, M. (2007). Stochastic comparisons of parallel systems when components have proportional hazard rates. Probab. Eng. Inf. Sci. 21:597–609.[Crossref], [Web of Science ®] , [Google Scholar]), Mao and Hu (2010 Mao, T., Hu, T. (2010). Equivalent characterizations on orderings of order statistics and sample ranges. Probab. Eng. Inf. Sci. 24:245–262.[Crossref], [Web of Science ®] , [Google Scholar]), Balakrishnan et al. (2014 Balakrishnan, N., Barmalzan, G., Haidari, A. (2014). On usual multivariate stochastic ordering of order statistics from heterogeneous beta variables. J. Multivariate Anal. 127:147–150.[Crossref], [Web of Science ®] , [Google Scholar]), and Torrado (2015 Torrado, N. (2015). On magnitude orderings between smallest order statistics from heterogeneous beta distributions. J. Math. Anal. Appl. 426:824–838.[Crossref], [Web of Science ®] , [Google Scholar]). A real application in system assembly and some numerical examples are also presented to illustrate the theoretical results.     

Examples of doubly stochastic measures supported on the graphs of two functions

A doubly stochastic measure (DSM) is a measure μ on the unit square so that μ([0, 1] × A) = μ(A × [0, 1]) = m(A) where m is Lebesgue measure. The set of DSMs forms a convex set in the space of measures. It is known that DSMs supported on the union of two graphs of invertible functions are extreme points of that convex set (Seethoff and Shiflett, 1977/78 Seethoff, T.L., Shiflett. (1977/78). Doubly stochastic measures with prescribed support. Z. Wahrscheinlichkeitstheorie und Verw. Gebiete 41(4):283–288.[Crossref], [Web of Science ®] , [Google Scholar]). In general, there are few examples of extreme points in the literature. There are examples of so-called hairpins where the functions involved are inverses of each other, but there are also examples of the union of the graphs of a function and its inverse does not support a DSM (Sherwood and Taylor, 1988 Sherwood, H., Taylor, M.D. (1988). Doubly stochastic measures with hairpin support. Probab. Theory Related Fields 78(4):617–626.[Crossref], [Web of Science ®] , [Google Scholar]). In this paper, for a function f in a certain class, we find companion functions g so that the union of the graphs of f and g support a DSM even though the union of the graphs of f and f-inverse do not.     

Testing monotonic equilibrium residual entropy of N-State Random Evolution

In this study, we propose an information measure of uncertainty associated with the random equilibrium residual lifetime of a system driven by N-State Random Evolution. A U-statistic test driven by a moment inequality is proposed for testing the hypothesis that the uncertainty of equilibrium remaining life of a system remains unchanged (when system is in the steady state) against the alternative situation when system’s equilibrium residual life has increasing uncertainty over time (i.e., the life distribution has Increasing Equilibrium Residual Entropy property). Some numerical results such as tabulated critical values and empirical power of the proposed test statistic are presented as well.     

多维汇率联动期权跳——扩散模型及其定价

在资产价格服从跳——扩散模型,汇率服从不同跳跃幅度的不连续模型的基础上,考虑用无套利分析方法得到了期权应满足的随机微分方程,并由Feynman-Kac公式,得到了多种欧式汇率联动期权的计算公式;当汇率联动期权具有随机寿命时,进一步研究了多种欧式汇率联动期权的价格。     

随机分形思想对农村经济合作组织建设的启示

农村经济增长乏力 ,已成为我国经济发展最重要的问题之一。本文通过对农村经济合作组织建设必要性的分析 ,指出了农村经济合作组织建设在农村经济发展及农村居民收入水平提高中的重要作用 ;并结合随机分形思想 ,提出了发展农村经济合作组织的若干思路 ;最后 ,指出了促进农村经济合作组织建设过程中应注意的几个问题。     

论发展低碳经济的减排政策工具

为解决温室气体排放的外部性问题,各种减排政策工具应运而生。根据作用效果的不同,可分为抑制排放的政策工具和鼓励促进低排放的政策工具。在抑制排放的政策工具中,碳税和碳排放交易采用了不同的政策机理,碳税更适用于市场机制不完善的发展中国家,而碳排放交易则更适用于市场机制比较完善、经济发展成熟的发达国家。在鼓励促进低排放的政策工具中,通过综合运用财政补贴、税收优惠和差别定价等措施,对可再生能源的发展可发挥重要作用。     

农机服务发展与粮食生产效率研究:2004—2016——基于变系数随机前沿分析

采用“两步法”研究了农机服务发展与中国粮食生产效率的关系.基于2004-2016年全国31省份粮食生产投入产出的面板数据,利用变系数随机前沿分析方法测算了中国粮食生产的技术变化、技术效率以及全要素生产率,然后构建农机服务发展影响粮食生产效率的OLS回归模型.结果表明:(1)31省份粮食生产的投入要素产出弹性和技术效率存在明显差异,2008年粮食技术变化最为明显,粮食全要素生产率的增长在2008年高达5%.(2)农机服务在2008年以后对粮食全要素生产率的增长具有显著的促进作用,农机服务对粮食TFP的作用存在一定的滞后效应.(3)农机服务发展与劳动产出弹性具有替代关系,与化肥和机械产出弹性具有互补关系.在三大粮食作物中,小麦机械化程度最高,水稻和玉米的机械化程度还有待提升.     

我国农村流通产业技术效率及其影响因素——基于随机前沿模型的分析

采用超越对数生产函数的随机前沿模型,基于2000~2009年我国省级面板数据,测算了我国农村流通产业的技术效率,并考察了我国农村流通产业技术效率的影响因素。实证结果表明:我国农村流通产业存在显著的技术非效率现象,但这种非效率现象有降低的趋势,地区间农村流通产业效率差异也有逐步缩小的趋势。研究认为,完善农村基础设施、增加农村公共服务供给有助于提高农村流通产业技术效率水平。