Using the dependent wild bootstrap for the nonparametric goodness-of-fit test for density functions

In this paper, we consider the well-known nonparametric consistent model-specification test for the stationary density function (see [Aït-Sahalia Y. Testing continuous-time models of the spot interest rate. Rev Financ Stud. 1996;9:385–426; Li Q. Nonparametric testing of closeness between two unknown distribution functions. Econ Rev. 1996;15:261–274; Fan Y, Ullah A. On goodness-of-fit tests for weakly dependent processes using kernel method. J Nonparametric Stat. 2000;11:337–360]) and reinvestigate it carefully using asymptotics and simulation. Our work reveals that the test is subject to power and size distortions, which are mainly caused by dependence or convergence rate changes under the null and alternative hypothesis. A dependent wild bootstrap is newly suggested as a feasible remedy to such distortions. Our result provides a complete explanation as well as a solution to the problem that experienced by Aït-Sahalia [Testing continuous-time models of the spot interest rate. Rev Financ Stud. 1996;9:385–426], that is, that the test rejects true models too often when independent and identically distributed asymptotic critical values are used.     

东亚国家OFDI的差异化选择

通过对本世纪初中国与上世纪七八十年代日、韩对外投资之间的比较研究发现:东亚各国对外投资在跨越贸易壁垒的意愿强度、对汇率波动的敏感度、区位/产业对外拓展路径及组织运营模式等方面均存在一定程度的差异化选择,而这种差异的背后恰恰反映出东亚各国所处对外投资发展阶段的不同以及积累国际化管理经验的能力差异。     

广州珠江黄埔大桥南汊主引桥衔接处线形控制技术

基于广州珠江黄埔大桥南汉悬索桥施工特点,针对悬索桥主引桥衔接处纵坡线形控制难题,提出解决方案.对于主桥端部钢箱梁纵坡线形的控制,提出两个调坡原则;对于伸缩缝纵坡线形的控制,提出须解决的关键问题及解决方法.所提方案解决了施工进度与施工工序之间的矛盾.     

DY-1型破乳剂的合成及应用

为解决大庆油田采油一厂原油脱水跑油问题，分别采用高碳醇，多乙烯多胺为起始剂，与环氧丙烷，环氧乙烷，合成2种单剂，再与溶剂复配制得1种高效的原油破乳剂DY-1，现场实用表明：DY-1在原油脱水过程中，可使综合污水含油，外输污水含油明显下降，应用效果良好。     

On the use of priors in goodness‐of‐fit tests

Priors are introduced into goodness‐of‐fit tests, both for unknown parameters in the tested distribution and on the alternative density. Neyman–Pearson theory leads to the test with the highest expected power. To make the test practical, we seek priors that make it likely a priori that the power will be larger than the level of the test but not too close to one. As a result, priors are sample size dependent. We explore this procedure in particular for priors that are defined via a Gaussian process approximation for the logarithm of the alternative density. In the case of testing for the uniform distribution, we show that the optimal test is of the U‐statistic type and establish limiting distributions for the optimal test statistic, both under the null hypothesis and averaged over the alternative hypotheses. The optimal test statistic is shown to be of the Cramér–von Mises type for specific choices of the Gaussian process involved. The methodology when parameters in the tested distribution are unknown is discussed and illustrated in the case of testing for the von Mises distribution. The Canadian Journal of Statistics 47: 560–579; 2019 © 2019 Statistical Society of Canada     

A Novel Approach to Chemical Mixture Risk Assessment—Linking Data from Population‐Based Epidemiology and Experimental Animal Tests

Humans are continuously exposed to chemicals with suspected or proven endocrine disrupting chemicals (EDCs). Risk management of EDCs presents a major unmet challenge because the available data for adverse health effects are generated by examining one compound at a time, whereas real‐life exposures are to mixtures of chemicals. In this work, we integrate epidemiological and experimental evidence toward a whole mixture strategy for risk assessment. To illustrate, we conduct the following four steps in a case study: (1) identification of single EDCs (“bad actors”)—measured in prenatal blood/urine in the SELMA study—that are associated with a shorter anogenital distance (AGD) in baby boys; (2) definition and construction of a “typical” mixture consisting of the “bad actors” identified in Step 1; (3) experimentally testing this mixture in an in vivo animal model to estimate a dose–response relationship and determine a point of departure (i.e., reference dose [RfD]) associated with an adverse health outcome; and (4) use a statistical measure of “sufficient similarity” to compare the experimental RfD (from Step 3) to the exposure measured in the human population and generate a “similar mixture risk indicator” (SMRI). The objective of this exercise is to generate a proof of concept for the systematic integration of epidemiological and experimental evidence with mixture risk assessment strategies. Using a whole mixture approach, we could find a higher rate of pregnant women under risk (13%) when comparing with the data from more traditional models of additivity (3%), or a compound‐by‐compound strategy (1.6%).     

我国未成年人犯罪治理体系的重构与完善——以刑罚的正当化根据为切入点

未成年人犯罪案件的高发常引发有关应否降低刑事责任年龄的争议,而争议的本质在于应否采用刑罚手段治理未成年人犯罪,即站在传统报应论立场的“以刑代教”与基于现代预防刑论的“以教为刑”之争。引发争议的现实原因在于我国现有未成年人犯罪治理体系的“失灵”,即存在刑罚与非刑罚处遇措施不明确、保安处分措施缺失与刑事政策偏重保护等方面的局限。在现有体系尚不完善之时,仅仅降低最低刑事责任年龄,扩大犯罪圈恐非良策。同时考虑到立法成本与司法现状,弹性刑事责任年龄制度的引入亦不可取。应着力从以下方面对现有体系进行完善:重视未成年人犯罪的特殊预防,在个案中充分贯彻个别化原则,并在现有的犯罪治理体系中增设保安处分规定。     

从乡村工商业看西欧庄园制的瓦解

一直以来,中世纪西欧的庄园经济总是被想象成以农业为主的自然经济。但是经过考察会发现,由于人们生活的需要和某些行业的特殊性,乡村生活中依然且必然有工商业的存在,工商业在以庄园制为主体的自然经济的夹缝中生存着。其经济属于一种二元经济模式。乡村手工业以庄园工场的形式独盛于中世纪早期,并不断发展。乡村的商业从最初必需品的交换,到后来生产力提高剩余产品的出现导致的交换,都表明乡村的商业也是一直存在且必然存在的。只是由于这些经济因素仍从属于封建的自然经济主体、不占据主导地位而未引起人们的重视。这些商品经济活动的存在不仅弥补了封建的自然经济的天然不足,同时,它的发展与后来城市兴起且壮大的工商业活动相结合,形成了里应外合的力量,最终冲破了封建阶级的堡垒,成为了西欧瓦解庄园制的一个重要因素。     

万里长城写生日记(之七)

到达丰镇后，安顿好了住处，助手杨子即去县委宣传部拜访。下午4点助手回来告知：宣传部的同志们非常热情，介绍了一些情况。但丰镇境内的长城可见者不多，大都只剩残基，更无甚文物古迹。城关东北角有一古庙，可以一看。     

Status of an alien turtle in city park waters and its potential threats to local biodiversity: the red-eared slider in Beijing

Urban Ecosystems - Invasive alien species pose a serious threat to native biodiversity and the ecosystem structure through predation or competition, and this threat is especially severe in China....