Efficient estimation of the PDF and the CDF of the inverse Rayleigh distribution

In this paper, we consider the estimation of the probability density function and the cumulative distribution function of the inverse Rayleigh distribution. In this regard, the following estimators are considered: uniformly minimum variance unbiased estimator, maximum likelihood (ML) estimator, percentile estimator, least squares estimator and weighted least squares estimator. To do so, analytical expressions are derived for the mean integrated squared error. As the result of simulation studies and real data applications indicate, when the sample size is not very small the ML estimator performs better than the others.     

Semiparametric jump-preserving estimation for single-index models

Estimation of the single-index model with a discontinuous unknown link function is considered in this paper. Existed refined minimum average variance estimation (rMAVE) method can estimate the single-index parameter and unknown link function simultaneously by minimising the average pointwise conditional variance, where the conditional variance can be estimated using the local linear fit method with centred kernel function. When there are jumps in the link function, big biases around jumps can appear. For this reason, we embed the jump-preserving technique in the rMAVE method, then propose an adaptive jump-preserving estimation procedure for the single-index model. Concretely speaking, the conditional variance is obtained by the one among local linear fits with centred, left-sided and right-sided kernel functions who has minimum weighted residual mean squares. The resulting estimators can preserve the jumps well and also give smooth estimates of the continuity parts. Asymptotic properties are established under some mild conditions. Simulations and real data analysis show the proposed method works well.     

科技创新对收入不平等的影响——基于企业发展与政府干预视角

科技创新对中国社会发展具有深远影响,但以往文献鲜有研究科技创新对社会公平的影响。本文以科技创新对收入不平等的影响及作用机制作为研究内容。理论方面,基于Solow经济增长理论构建数理模型,进行归纳分析。实证方面,运用2008年、2010—2013年和2015年CGSS与省级面板匹配数据进行实证检验,并对中介机制进行识别,最后进行异质性分析。研究发现:(1)基于企业自主发展维度,由于行业间与企业间研发能力等科技创新水平差异,将导致收入不平等的加剧;(2)基于政府主导干预维度,由于政府通过抽税补贴等产业政策拉大了行业间与企业间科技创新水平,将导致收入不平等的加剧;(3)科技创新能够加剧收入不平等程度;(4)进一步通过异质性检验发现,科技创新对收入不平等的作用是基于区域内人力资本水平、政府规模以及地理属性等多种因素影响的。因此,建议科技创新在促进经济发展效率的同时,也要控制其对社会公平的扭曲作用。     

Minimum-distance methods based on quadratic distances for transforms

A class of minimum-distance methods based on empirical transforms is considered. This class includes the minimum-chi-squared method, the K-L method for empirical characteristic functions, and the analogous method for empirical moment generating functions. Asymptotic properties of the minimum-distance estimators and goodness-of-fit test statistics are derived. A general analogue of the Rao-Robson statistic is formulated.     

一种新的子空间模式识别方法

提出了一种改进的LSM-ALSM子空间模式识别方法,将LSM的旋转策略引入ALSM,使子空间之间互不关联的情况得到改善,提高了ALSM对相似样本的区分能力。讨论中以性能函数代替经验函数来确定拒识规则的参数,实现了识别率、误识率与拒识率之间的最佳平衡;通过对有限字符集的实验结果表明,LSM-ALSM算法有效地改善了分类器的识别率和可靠性。     

浅谈律师提前介入

现代刑事诉讼程序除了其惩罚犯罪的功能外,更应强调的是保障人权以及维护诉讼程序的公正、合法、民主和文明。辩护,作为对国家追诉犯罪力量的一种制衡,是对被告人权利最有力的保障,是维系刑事诉讼合理构架的需要,是控辨平衡的支柱。新刑事诉讼法对此做出了较大改革,但在实践中辩护权利受到限制,控辩并未达到平等。从辩护制度的发展、对其宗旨、目的的探讨以及实践中的律师提前介入问题论述对被告人权利的保障以增强辩方与控方抗衡的力量,从而达到控辩平等,力求实现司法公正的结果价值。     

Augmenting a Submodular and Posi-modular Set Function by a Multigraph

Given a finite set V and a set function , we consider the problem of constructing an undirected multigraph G = (V,E) such that the cut function together has value at least 2 for all non-empty and proper subsets of V. If f is intersecting submodular and posi-modular, and satisfies the tripartite inequality, then we show that such a multigraph G with the minimum number of edges can be found in time, where is the time to compute the value of f(X) for a subset .     

Minimum ε-equivalent Circuit Size Problem

For a Boolean function f given by its truth table (of length ) and a parameter s the problem considered is whether there is a Boolean function g -equivalent to f, i.e., , and computed by a circuit of size at most s. In this paper we investigate the complexity of this problem and show that for specific values of it is unlikely to be in P/poly. Under the same assumptions we also consider the optimization variant of the problem and prove its inapproximability.     

学校欺负干预研究综述

学校欺负及其干预问题已经成为当前公众和研究者关注的世界性主题.一些国家进行了欺负干预研究,效果不尽相同.其主要影响因素是干预方案的构成、学生的年龄、儿童的性别、外部支持和持续的时间等.未来研究的发展趋势是方法多元化、干预时间提前化、干预思路生态化、效果持久化和跨文化的研究.     

风险、预算、信息与有效预防--传染病预防的经济学分析

对传染病的经济学分析才刚刚开始,分析主要集中在对艾滋病、天花等疾病的分析上,给出了传染病防治的一些基本模型.但这些分析没有形成一个系统的框架.我们从传染病的个人预防出发,分别讨论了风险、预算、信息三个因素对个人预防行为的作用,得出的结论是基于上述约束的个人预防无法实现传染病的有效预防,需要政府等外力的介入以突破个人预防困境.