Recursive distribution estimator defined by stochastic approximation method using Bernstein polynomials

We propose a recursive distribution estimator using Robbins-Monro's algorithm and Bernstein polynomials. We study the properties of the recursive estimator, as a competitor of Vitale's distribution estimator. We show that, with optimal parameters, our proposal dominates Vitale's estimator in terms of the mean integrated squared error. Finally, we confirm theoretical result throught a simulation study.     

中韩港口经营人责任限制制度比较研究

港口经营人能否限制赔偿责任取决于其法律地位的正确界定。文章从承运人责任限制的立法依据入手，比较分析中、韩法下港口经营人的法律地位以及法院对提单背面的港口经营人责任限制条款的效力的态度，认为港口经营人应为独立合同人，其不能直接根据《海商法》享有责任限制的权利，但司法实践中应认定提单背面的港口经营人责任限制条款有效。     

F～K（m1，m2，m3）-S的必要条件

用P(G,λ)表示图G的色多项式。本文得到了图F与K(m1,m2,m3)-S色等价的必要条件,为我们进一步研究形如K(m1,m2,m3)-S的色唯一图提供了基础。     

Psychosocial variables related to transit safety: The application of catastrophe theory

This research applied a paradigm for the study of occupational safety and health risks in manufacturing settings to the risks associated with urban and regional transit operation. Subjects were 290 transit operators who completed a questionnaire measuring safety management, danger ratings, beliefs about accident control, work experience, physical stress, social stress, anxiety, environmental hazards, transit hazards (assaults and insults upon the operator, the need to reprimand passengers for various infractions, etc.), vehicle crashes and operator injuries, and alcohol and drug use. Principal findings were that operator injuries were most closely associated with transit hazards, which were more frequent at night and on the least desirable routes. Injuries occurred in a climate of elevated stress and anxiety which may have hampered the operators' ability to respond effectively to potentially dangerous situations. The cusp catastrophe model provided a non-linear dynamic explanation for accident occurrence and was more accurate (R = 0.71) for modelling accident incidence than the next best linear alternative (R = 0.51).     

PROPERTIES OF THE PATTERNED VECH OPERATOR

The vec operator arranges the columns of a matrix one below the other. When the matrix is symmetric such elements are not distinct but an extraction of only the distinct elements on or below the diagonal forms the operation denoted by vech. For other types of patterned matrices a ‘patterned vech’ operator is defined. The transformations from vech to vec are not uniquely defined. Here we examine properties of linear transformations which overcome the lack of uniqueness and develop properties of such linear transformations.     

r-循环矩阵求逆和广义逆的Euclid算法

利用多项式的Euclid算法给出了非奇异的r-循环矩阵求逆矩阵的一个新算法,该算法同时推广到用于求奇异r-循环矩阵的群逆和Moore-Penrose逆。最后给出了应用该算法的数值例子。     

对一道题目证明的辨析

剖析了许多教材中一道题目证明的错误 ,并通过数学归纳法给出了正确的证明。     

Generalized likelihood ratio tests for the structure of semiparametric additive models

Semiparametric additive models (SAMs) are very useful in multivariate nonparametric regression. In this paper, the authors study nonparametric testing problems for the nonparametric components of SAMs. Using the backfitting algorithm and the local polynomial smoothing technique, they extend to SAMs the generalized likelihood ratio tests of Fan &Jiang (2005). The authors show that the proposed tests possess the Wilks‐type property and that they can detect alternatives nearing the null hypothesis with a rate arbitrarily close to root‐n while error distributions are unspecified. They report simulations which demonstrate the Wilks phenomenon and the powers of their tests. They illustrate the performance of their approach by simulation and using the Boston housing data set.     

异质性农业经营主体技术采纳行为差异化研究

基于农业技术推广的视角,对异质性农业经营主体技术采纳行为的差异性及其影响因素进行了理论探讨,并利用微观调查数据进行了验证。研究表明：农业生产要素规模、结构及技能水平差异,导致异质性农业经营主体技术采纳成本、收益及风险判断的不同,使其技术内容、推广途径及推广主体选择呈现显著差异;小规模兼业农户偏好由政府推广机构通过技术人员现场指导的方式提供生产阶段的技术;家庭农场（专业大户）偏好由农资企业通过公共传媒提供与其规模经营特征相适应的技术;农民专业合作组织偏好通过组织自身的技术选择及应用满足其多元化技术需求;农业企业偏好通过经营性推广主体的多元化推广途径,获得服务其经营目标的各类技术。因此,为了提升农技推广效率和农技服务有效供给水平,应针对不同规模、不同组织化的农业经营主体制定农技精准推广方案,提高农业技术供求的匹配程度。     

关于完全t部图的色等价性

设K（n1,n2,…,nt）表示完全t部图,K(n1,n2,…,nt）－A表示从K（n1,n2,…,nt）中删去子边集A所得之图．本文证明了：令G＝K（n1,n2,…,nt）,J为整数集,R为实数集．设简单图Y满足Y～G,则且进一步有：若s＞0且αi∈R（i＝1,2…．t）．则