Comparison of Separable Components in Different Samples

Abstract.  Imagine we have two different samples and are interested in doing semi- or non-parametric regression analysis in each of them, possibly on the same model. In this paper, we consider the problem of testing whether a specific covariate has different impacts on the regression curve in these two samples. We compare the regression curves of different samples but are interested in specific differences instead of testing for equality of the whole regression function. Our procedure does allow for random designs, different sample sizes, different variance functions, different sets of regressors with different impact functions, etc. As we use the marginal integration approach, this method can be applied to any strong, weak or latent separable model as well as to additive interaction models to compare the lower dimensional separable components between the different samples. Thus, in the case of having separable models, our procedure includes the possibility of comparing the whole regression curves, thereby avoiding the curse of dimensionality. It is shown that bootstrap fails in theory and practice. Therefore, we propose a subsampling procedure with automatic choice of subsample size. We present a complete asymptotic theory and an extensive simulation study.     

Empirical likelihood tests for two‐sample problems via nonparametric density estimation

The authors study the problem of testing whether two populations have the same law by comparing kernel estimators of the two density functions. The proposed test statistic is based on a local empirical likelihood approach. They obtain the asymptotic distribution of the test statistic and propose a bootstrap approximation to calibrate the test. A simulation study is carried out in which the proposed method is compared with two competitors, and a procedure to select the bandwidth parameter is studied. The proposed test can be extended to more than two samples and to multivariate distributions.     

现代汽车安全技术分析

介绍了汽车的主动安全技术与被动安全技术，通过对二者技术范畴及应用前景的分析比较，阐明了主动安全技术与被动安全技术的结合是未来汽车安全发展的主要趋势，并且对主动安全技术的一些前沿课题作了介绍．     

关于模拟静电场的描绘的两种方法的比较

本文将模拟静电场的有关理论同实验方法，实验数据进行比较，指出在模拟静电场的描述的实验中，采用电压表进行测量时所存在的问题，提出了用电位差计代用，以补偿电压表的不足之处，从而改进该实验的具体方法。     

创业投资:德国和美国的比较研究

在对美国和德国的创业投资的调查研究中,对照美国的研究结果,向德国的创业投资家调查了以下两个问题:1)在评估一项投资的时候创业投资家更看重创业者什么?2)根据一项创业投资计划,他们怎样与创业企业合作。调查结果显示,在创业的早期阶段和扩张阶段,德国创业投资家评估一项商业计划时,比较关注创业企业的发展潜力。他们强调,创业者所表现出的领导才能和对市场的熟悉程度是决定创业投资的必要条件。晚期阶段的创业投资家与早期阶段的创业投资家相比,不太容易和创业者成为亲密伙伴;他们对创业企业所提供的管理帮助也比较少。创业投资公司的规模在很大程度上影响创业投资的某些投资特征。与美国的研究结果相似,大规模的创业投资公司和小规模的创业投资公司运作的差异主要在于平均投资规模。在德国,随着创业投资公司规模的扩大,其投资的地域范围也在扩大。至于投资过程,当创业投资公司是主要投资者时,投资公司的规模与其所花费的评估和沟通时间(从开始与创业者接洽到进行融资之间)负相关。融资的准备时间与创业投资公司的员工数之间的关系,小规模的创业投资公司更有效率。     

Compressed Natural Gas Bus Safety: A Quantitative Risk Assessment

This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to variations in component failure rates and consequences of fire events. The components and subsystems that contribute most to fire safety risk are determined. Finally, the results are compared to fire risks of the present generation of diesel-fueled school buses. Direct computation of the safety risks associated with diesel-powered vehicles is possible because these are mature technologies for which historical performance data are available. Because of limited experience, fatal accident data for CNG bus fleets are minimal. Therefore, this study uses the probabilistic risk assessment (PRA) approach to model and predict fire safety risk of CNG buses. Generic failure data, engineering judgments, and assumptions are used in this study. This study predicts the mean fire fatality risk for typical CNG buses as approximately 0.23 fatalities per 100-million miles for all people involved, including bus passengers. The study estimates mean values of 0.16 fatalities per 100-million miles for bus passengers only. Based on historical data, diesel school bus mean fire fatality risk is 0.091 and 0.0007 per 100-million miles for all people and bus passengers, respectively. One can therefore conclude that CNG buses are more prone to fire fatality risk by 2.5 times that of diesel buses, with the bus passengers being more at risk by over two orders of magnitude. The study estimates a mean fire risk frequency of 2.2 x 10(-5) fatalities/bus per year. The 5% and 95% uncertainty bounds are 9.1 x 10(-6) and 4.0 x 10(-5), respectively. The risk result was found to be affected most by failure rates of pressure relief valves, CNG cylinders, and fuel piping.     

英汉语言中动物词语的对比

世界各民族语言中有大量有关动物的习俗语和谚语，这些语言背后蕴藏着深厚的文化积淀，反映不同民族对动物相同或不同的情感态度。文章在前期对中国传统文化中十二生肖动物及其它动物词语研究的基础上，主要对汉语和英语语言中有关动物的成语、习俗语和谚语进行对比分析，从有关动物词语的字面意义出发，探讨挖掘他们的比喻意义、联想意义．寻找出英汉语言中动物词语的共同点和差异，揭示两种语言中动物词语在语义表达上的主要特点。指出英汉语言中包含动物名称的词语语义形成的基础，两种语言中运用动物词语进行语义表述的对等性特点，以及这些包含动物的词语所蕴涵的文化特征。     

The residential home – what difference does it make?: Comparing the public systems of care for the elderly and disabled in two Swedish municipalities

Two municipalities in Sweden – Solna and Sigtuna – have taken part in a project (the ASIM project) aimed at developing a system for monitoring and analysing the public system of long-term care and assistance for elderly and disabled people. The two municipalities have chosen different alternatives in the question of residential homes. In Solna they have been retained and in Sigtuna they have been converted into sheltered housing. By separating the clients into different classes of dependence using the ASIM assessment, it is shown that in Solna, compared with Sigtuna, fewer of the most dependent clients are in long-term hospital care and fewer of the high-medium category are in domiciliary care. The data were used to calculate the distribution of the clients and the average dependence on the different levels of care if Solna were to apply the care pattern of Sigtuna and vice versa.     

关于鲁迅与陈独秀等“随感录”的比较

本文通过对鲁迅与陈独秀等人《随感录》的比较，分析了他们在《随感录》内容指向、提炼与构思、文风特征及艺术品性等方面的诸多差异，对比性显示了鲁迅关注中国现实问题的独异视角和艺术上的独特创造     

Bayes and empirical Bayes shrinkage estimation of regression coefficients

For a moderate or large number of regression coefficients, shrinkage estimates towards an overall mean are obtained by Bayes and empirical Bayes methods. For a special case, the Bayes and empirical Bayes shrinking weights are shown to be asymptotically equivalent as the amount of shrinkage goes to zero. Based on comparisons between Bayes and empirical Bayes solutions, a modification of the empirical Bayes shrinking weights designed to guard against unreasonable overshrinking is suggested. A numerical example is given.