医疗体制改革背景下“看病难”问题的经济学分析

医疗体制改革以来,我国医疗卫生事业取得了显著成效,医疗服务的规模不断扩大,卫生条件得到改善,医疗保障制度也日趋完善,但是"看病难"的问题仍然存在。这主要是因为,医疗服务市场的供需不平衡,优质医疗资源的过度集中与群众医疗需求之间产生了巨大的差距,其实质则是市场失灵与政府干预不足。对此,通过研究"看病难"问题的现状,对其进行经济学分析,最后提出解决该问题的对策。     

研究生英语教学新思路探索

通过分析非英语专业研究生英语教学中存在的主要问题,并在社会不断发展变化、学科水平不断提高、学生学习需求日益多样化的背景下,探讨研究生英语教学新思路。提出研究生英语应调整教学定位,走学术英语的道路,培养目标是提高学生的综合语言素质,增强学术研究和国际交流的能力。同时从课程设置、教学内容和师资队伍建设的角度对研究生英语教学进行改革。     

Evaluation of incomplete multiple diagnostic tests,with an application in the colon cancer family registry study

Accurate diagnosis of a molecularly defined subtype of cancer is often an important step toward its effective control and treatment. For the diagnosis of some subtypes of a cancer, a gold standard with perfect sensitivity and specificity may be unavailable. In those scenarios, tumor subtype status is commonly measured by multiple imperfect diagnostic markers. Additionally, in many such studies, some subjects are only measured by a subset of diagnostic tests and the missing probabilities may depend on the unknown disease status. In this paper, we present statistical methods based on the EM algorithm to evaluate incomplete multiple imperfect diagnostic tests under a missing at random assumption and one missing not at random scenario. We apply the proposed methods to a real data set from the National Cancer Institute (NCI) colon cancer family registry on diagnosing microsatellite instability for hereditary non-polyposis colorectal cancer to estimate diagnostic accuracy parameters (i.e. sensitivities and specificities), prevalence, and potential differential missing probabilities for 11 biomarker tests. Simulations are also conducted to evaluate the small-sample performance of our methods.     

辽宁期刊终有史

从1905年辽宁开始有期刊以来的100多年间,始终没有一部辽宁期刊史,甚至连一篇简单的期刊史叙述文宁也难找到。所以当2011年最后一个月的第一天拿到《辽宁期刊史》样书的时候,作为本书执行主编、撰稿人和装帧设计者,我心中自然有些激动。     

关于企业对员工履行社会责任的现实观照——以黑龙江省H高新技术企业为例

通过对黑龙江省H高新技术企业履行员工社会责任现状的调查,发现企业在履行员工社会责任的过程中还存在诸如员工被动加班、受到歧视侮辱、工作环境差、员工生涯发展通道不畅等问题。只有政府加大监管力度、发挥全社会的监督功能、企业引入社会工作等一系列措施,才能使企业社会责任实践落到实处,使员工的福利水平真正得到提升。     

Sample Size and Power Calculations for Left-Truncated Normal Distribution

Abstract

Sample size calculation is an important component in designing an experiment or a survey. In a wide variety of fields—including management science, insurance, and biological and medical science—truncated normal distributions are encountered in many applications. However, the sample size required for the left-truncated normal distribution has not been investigated, because the distribution of the sample mean from the left-truncated normal distribution is complex and difficult to obtain. This paper compares an ad hoc approach to two newly proposed methods based on the Central Limit Theorem and on a high degree saddlepoint approximation for calculating the required sample size with the prespecified power. As shown by use of simulations and an example of health insurance cost in China, the ad hoc approach underestimates the sample size required to achieve prespecified power. The method based on the high degree saddlepoint approximation provides valid sample size and power calculations, and it performs better than the Central Limit Theorem. When the sample size is not too small, the Central Limit Theorem also provides a valid, but relatively simple tool to approximate that sample size.     

Distance Between Random Points in Two Rectangular Cities

ABSTRACT

The travel distance between two cities of rectangular shape is considered. Two uniformly distributed random points, one from each city, are taken. Their straight path travel distance is then measured. The explicit forms for the probability density function of this distance and its expected value are obtained. Numerical results of calculating the exact expected distance and the estimated distance as well as computer simulation are given for various cases. The integer moments of the distance are also discussed.     

Trajectory Modeling of Longitudinal Binary Data: Application of the EM Algorithm for Mixture Models

A developmental trajectory describes the course of behavior over time. Identifying multiple trajectories within an overall developmental process permits a focus on subgroups of particular interest. We introduce a framework for identifying trajectories by using the Expectation-Maximization (EM) algorithm to fit semiparametric mixtures of logistic distributions to longitudinal binary data. For performance comparison, we consider full maximization algorithms (PROC TRAJ in SAS), standard EM, and two other EM-based algorithms for speeding up convergence. Simulation shows that EM methods produce more accurate parameter estimates. The EM methodology is illustrated with a longitudinal dataset involving adolescents smoking behaviors.     

从国际视角提升对科学发展观的认识

二战结束以来的五六十年中,人类围绕着“发展”问题进行了不懈探索,发展观不断演变：20世纪五六十年代的“第一代发展观”可以概括为“发展=经济增长”;经过改善的“第二代发展观”可以概括为“发展=经济增长＋社会变革”;20世纪80年代以来逐步形成的“第三代发展观”可以概括为“发展：经济增长＋社会进步＋以人为中心＋可持续发展”;世纪之交的当代前沿发展观则是“以自由看待发展”。中国共产党提出的科学发展观,并不是对国外发展经验的简单承续,而是既有借鉴又有创新。党的十七大报告的精辟概括使科学发展观成为一个完整的理论体系,在国际发展理念中融进了更加科学的内涵,提升了其理论意义和实践价值。这种提升集中体现在“三个创新”上：第一,创新“发展是发展中国家的第一要务”;第二,创新“全面、协调、可持续发展的基本要求”;第三,创新“统筹兼顾的根本方法”。     

从跨文化交际角度探讨“中国英语”存在的合理性

中国英语是跨文化交流的产物,蕴含着丰富的中国文化,是架构东西方文化差异的桥梁,是海外了解中国的最佳渠道.在改革开放三十年的今天,它具有广阔的应用前景和实用价值,是中国联系世界必不可少的媒介,在跨文化交际中有助于传播中国特色文化,体现个人和民族认同感,并能抵制文化霸权,从而实现平等交际.从跨文化交际角度来说,中国英语具有其存在的合理性.