The Two-interval Line-segment Problem

In this paper we define and study the non-parametric maximum likelihood estimator (NPMLE) in the one-dimensional line-segment problem, where we observe line-segments on the real line through an interval with a gap which is smaller than the two remaining intervals. We define the self-consistency equations for the NPMLE and provide a quick algorithm for solving them. We prove supremum norm weak convergence to a Gaussian process and efficiency of the NPMLE. The problem has a geological application in the study of the lifespan of species     

Semiparametric Quantile Regression Analysis of Right‐censored and Length‐biased Failure Time Data with Partially Linear Varying Effects

Right‐censored and length‐biased failure time data arise in many fields including cross‐sectional prevalent cohort studies, and their analysis has recently attracted a great deal of attention. It is well‐known that for regression analysis of failure time data, two commonly used approaches are hazard‐based and quantile‐based procedures, and most of the existing methods are the hazard‐based ones. In this paper, we consider quantile regression analysis of right‐censored and length‐biased data and present a semiparametric varying‐coefficient partially linear model. For estimation of regression parameters, a three‐stage procedure that makes use of the inverse probability weighted technique is developed, and the asymptotic properties of the resulting estimators are established. In addition, the approach allows the dependence of the censoring variable on covariates, while most of the existing methods assume the independence between censoring variables and covariates. A simulation study is conducted and suggests that the proposed approach works well in practical situations. Also, an illustrative example is provided.     

A modified internal rate of return model for capital rationing in project selection

The ability of a company to finance viable projects depends on the availability of funds, and this too is a function of time, interest rate and risk factors among others. Factors such as these would lead to limited fund availability, which would necessitate capital rationing. Linear/integer programming and profitability index are often used to tackle this problem for optimal solution. A third approach utilizing a modified internal rate of return (IRR) is proposed. To overcome the difficulty usually encountered in calculating IRR, a small program coded in BASIC is presented. Even though discounting the cash outflows beyond the initial year should have been ideal in the linear programming formulation, this paper casts doubts as to the validity of the solution derived from it, as different discount rates seem to produce very conflicting results from the same set of investment options. This is also applicable to profitability index. While efforts are being made to correct these lapses, the modified IRR model has been found useful in arriving at an optimum solution both for the single-period as well as for the multi-stage situation.     

江户时期儒学家浅见絅斋《养子辩证》之探析

浅见纲斋在《养子辩证》的主要阐明了父子、兄弟之伦理不可乱,故而不可以异族之子为自己的养子。如果随意交换应有的位置,是很荒谬的,所以著书说明。《养子辩证》中某些观点虽然不免偏颇,但是通过浅见纲斋在《养子辩证》中引用中国历史上大量的事例来看,他一丝不苟、引经据典、博览我国儒家群书,不愧为日本江户时代著名的儒学家和哲学家。     

试析当前社会安置工作现状问题及对策——以T市为例

目前,社会安置工作面临人户分离现象严重、查找困难,衔接工作难以落实等现实问题。鉴于此,笔者认为应通过完善衔接工作制度,理顺社会安置工作的体制机制,加强信息化体系建设,不断规范刑释解教人员社会安置工作等措施,最大限度地预防和减少刑释解教人员重新违法犯罪。     

当代大学生政治参与现状研究

大学生政治参与是一个国家民主政治高度发展的表相特征,目前,我国大学生政治参与普遍存在参与认知不明确、治分析能力低、利化趋向明显、治参与效能感偏低等问题。在充分分析上述现状产生原因的基础上,从体制机制完善、政治文化建设、学校教育改革、拓展参与渠道等方面提出了相应的解决措施,以期推进我国大学生政治参与高速有序地发展。     

我国重新犯罪现状与发展趋势研究

我国尽管1997年刑法将累犯的构成期限从3年延长至5年,但刑满释放人员的重新犯罪率不仅没有下降,反而呈现持续升高的走势。从不同地域之间的比较看,重新犯罪作为社会犯罪的一个重要组成部分,随着社会犯罪的增长而增长,只是增涨的幅度要小于社会犯罪。预计我国刑释人员重新犯罪将在今后一个相当长的历史时期内,呈现总量波动上升,高位持续振荡的发展态势。     

中型石化企业组织结构的现状、问题及成因分析

21世纪以来,国内一些石化公司的经营模式、发展规模、管理体制都发生了重大的变化。传统的企业组织结构已经难以适应当前世界经济的发展趋势,严重制约着企业的进一步发展。应改变原有的企业组织结构,解决优化企业组织结构过程中存在的问题,以有利于企业未来的发展。     

吊簿:姻亲交往秩序的文化图像

本文对山东南部红山峪村①的一份吊簿进行了深入、细致的分析。文章认为,吊簿作为一种民间文献,在人们生活中是为了方便姻亲交往而记录的,其间反映的内容非常之丰富。吊簿不仅展现出在人们观念之中的以死者为中心的亲属网络,而且其本身就是一张姻亲交往秩序的文化图像。它以礼物的价值和指标清晰地体现出联姻家族之间的“亲戚理”——阶序性关系。这种阶序性关系与礼物的内容和经济价值的大小有一个互释的关系,人群与人群之间的关系决定了礼物的价值和流向,反过来,礼物的价值和流向也足以区别人群之间的关系。熟稔村落生活的人根据礼金和实物,基本上可以准确判断出上礼者在死者的亲属序列中的具体位置。     

Learning, Structural Instability, and Present Value Calculations

Present value calculations require predictions of cash flows both at near and distant future points in time. Such predictions are generally surrounded by considerable uncertainty and may critically depend on assumptions about parameter values as well as the form and stability of the data generating process underlying the cash flows. This paper presents new theoretical results for the existence of the infinite sum of discounted expected future values under uncertainty about the parameters characterizing the growth rate of the cash flow process. Furthermore, we explore the consequences for present values of relaxing the stability assumption in a way that allows for past and future breaks to the underlying cash flow process. We find that such breaks can lead to considerable changes in present values.