Two-dimensional density estimation using smooth invertible transformations

We investigate the problem of estimating a smooth invertible transformation f when observing independent samples X₁,…,X_n∼P°f where P is a known measure. We focus on the two-dimensional case where P and f are defined on R². We present a flexible class of smooth invertible transformations in two dimensions with variational equations for optimizing over the classes, then study the problem of estimating the transformation f by penalized maximum likelihood estimation. We apply our methodology to the case when P°f has a density with respect to Lebesgue measure on R² and demonstrate improvements over kernel density estimation on three examples.     

Construction of optimal supersaturated design with large number of levels

Inspired by the ideas of column and row juxtaposition in Liu and Lin (2009) and level transformation in Yamada and Lin (1999), this paper presents a new method for constructing optimal supersaturated designs (SSDs). This method provides a convenient way to construct mixed-level designs with relatively large numbers of levels, avoiding the blind search and numerous calculations by computers. The goodness of the resulting SSDs is judged by the χ² (Yamada and Lin, 1999 and Yamada and Matsui, 2002) and J₂ (Xu, 2002) criteria. Some nice properties of the new designs are also provided.     

Distribution-free test in Tobit mean regression model

This paper discusses the problem of fitting a parametric model in Tobit mean regression models. The proposed test is based on the supremum of the Khamaladze-type transformation of a partial sum process of calibrated residuals. The asymptotic null distribution of this transformed process is shown to be the same as that of a time-transformed standard Brownian motion. Consistency of this sequence of tests against some fixed alternatives and asymptotic power under some local nonparametric alternatives are also discussed. Simulation studies are conducted to assess the finite sample performance of the proposed test. The power comparison with some existing tests shows some superiority of the proposed test at the chosen alternatives.     

Semiparametric Estimation of a Proportional Hazard Model with Unobserved Heterogeneity

The proportional hazard model with unobserved heterogeneity gives the hazard function of a random variable conditional on covariates and a second random variable representing unobserved heterogeneity. This paper shows how to estimate the baseline hazard function and the distribution of the unobserved heterogeneity nonparametrically. The baseline hazard function and heterogeneity distribution are assumed to satisfy smoothness conditions but are not assumed to belong to known, finite-dimensional, parametric families. Existing estimators assume that the baseline hazard function or heterogeneity distribution belongs to a known parametric family. Thus, the estimators presented here are more general than existing ones.     

社会转型时期群体性治安事件的现状及对策

在当前社会变革体制转换利益调整的大背景下,人民内部矛盾随着各种诱发因素的此消彼长,不断滋生发展、蔓延、转化,呈数量增多、复杂性加剧之势。由此引发的群体性事件也日趋突出,妨害社会和经济秩序,影响社会稳定,阻碍社会主义建设事业的发展。     

转型期中国共产党执政合法性建设研究

我国目前正处于向社会主义现代化社会的全面转型时期。社会转型期中国共产党执政条件和社会环境也发生着深刻变化,传统的政治合法性资源逐步流失,执政党政治合法性面临新的挑战。应对挑战,我党应当从政治、经济、文化、社会四个方面努力,进一步加强我国执政党的政治合法性建设。     

生态文明研究新进展：一个文献综述

生态文明是建立在经济效益、社会效益与环境效益多赢基础上的一种文明模式,反映了社会文明发展在生产方式上的进步,要求对工业化生产方式进行生态化改造,形成生态化的生产方式。发展生态文明,突破口是建设环境友好型社会,关键在于人类价值取向需要发生转换。学术界对于建设生态文明的途径、方法和基本措施形成了六大代表性的理论：三个平台说、机制建构说、多层次发展说、注重理念说、生态主导说、＂五力＂模型设想。     

论我国公共治理中公民角色的多元并存与转化

目前,公共治理中的公民角色研究呈现出对治理型公民的推崇和对顾客型公民的批判。但诸多原因决定了在我国现阶段公共治理中,治理者与顾客二种公民角色将共生共存,有必要区别分析、深入研究,并采用有效方法推动顾客型公民向治理型公民转化。     

论中国诗学的“圆美”崇尚及其文本书写机制

关注中国诗学对圆美的崇尚,针对偏重文化勾陈、哲学溯源的研究现状,采取深入到诗文本内里的研究路径与方法:析解文本各层次圆的不同意谓,思考"诗何以圆"。本文提出:诗圆的最高境界是包蕴在以圆形物喻诗论说中的圆转无穷之圆,诗文本咏物、叙事、书写人生情境呈现出的"是又不是、不是又是"的特殊态势形成了体验上的回环往复,从而使得诗文本圆转无穷。造就"是又不是,不是又是"特殊态势的书写机制,在"咏物"中最为复杂。咏物徘徊于"是"与"不是"之间缘于对物自性的悬置,其手法主要有文化侵入和幻化。而之所以产生悬置物自性这种书写机制,是因为中国文化中以道为本源的宇宙观对物之存在有特殊的阐说。     

试析我国转型期国家与社会权力关系变迁

在以计划经济为基础的政治形态中,通过体制和组织的力量,形成党、国家和社会“三位一体”政治权力关系。但在改革开放后,社会主义市场经济体制的建立和发展,动摇了党与国家、党与社会关系的传统基础,带来了国家与社会关系的深刻变化。因此,在社会转型期合理调整三者之间的权力关系便成为我国政治发展的一个重要方面。