风险投资家的双重逆向选择风险规避机制

风险投资过程中,由于信息的不对称,投资者与风险投资家之间、风险投资家与风险企业家之间存在着双重逆向选择风险。在融资阶段的信号传递机制中,作为代理人的风险投资家,选择融资计划书信号,向作为委托人的投资者传递其能力信号,投资者据此修正自己的先验概率,然后根据后验概率,与风险投资家签定合同规避风险;在投资阶段的信息甄别机制中,作为中间委托人的风险投资家先提供合同,这时唯一可能是分离均衡,即不同类型的风险企业家选择不同的合同规避风险。     

论克隆技术发展与科技伦理进步

克隆技术的发展使克隆人成为可能,它给我们带来了一系列的伦理学问题。但克隆技术的发展不可能完全禁止,科技伦理应该采取开放的框架去积极地研究这些问题。克隆技术和科技伦理应该协调发展,科技伦理要为克隆技术的发展提供指导。目前,克隆技术应该有控制地发展。     

马寅初的人口质量观及其现实意义——纪念马寅初诞辰120周年

注重人口质量是马寅初人口思想对马尔萨斯人口论的实质性超越.马寅初关于人口质量的观点主要体现于:人口质量与人口数量是对立的统一;在新时代,人不在乎多,而在乎精;人口质量的提高是德、智、体全面的提高和全民的提高;提高人口质量不能离开本国国情.在现代化进程中我们重温马寅初关于提高人口质量方面的有关观点和主张,有助于我们处理好提高人口质量与稳定低生育水平、保护资源环境、提高农民收入等方面的关系.     

On pooling data summaries in the absence of interactions “response-by-study”

The standard hypothesis testing procedure in meta-analysis (or multi-center clinical trials) in the absence of treatment-by-center interaction relies on approximating the null distribution of the standard test statistic by a standard normal distribution. For relatively small sample sizes, the standard procedure has been shown by various authors to have poor control of the type I error probability, leading to too many liberal decisions. In this article, two test procedures are proposed, which rely on thet—distribution as the reference distribution. A simulation study indicates that the proposed procedures attain significance levels closer to the nominal level compared with the standard procedure.     

Narrating Significant Experience: Reflective Accounts and the Production of (Self) Knowledge

Notwithstanding the rise of evidence-based practice, other tendencieswithin social work scholarship are also discernible. One ofthese is the study of the everyday, routine accomplishment ofpractice, drawing on microsociological methods and techniques.In this article, I apply techniques drawn from narrative anddiscourse analysis to the study of reflective practice accounts,which hold an important place in social work education. In particular,it is relevant to examine the form that reflective accountstake and the rhetorical and narrative devices deployed withinthem to accomplish a competent professional identity. My argumentis not that such accounts of practice are untruthful, ratherI propose that we would do well to move beyond taking texts(and talk) for granted and treating language as merely the mediumfor expressing inner thoughts and feelings. Social work shouldtake seriously the need to explore its modes of representationand to cultivate a more self-conscious approach to the way professionaland client identities are produced in practice.     

企业行为中的利己主义、理性主义及伦理主义——企业社会责任的发展路径及系统结构探微

企业的牟利天性从某种意义上讲是一种源于生物学方面的利己天性,这种天性的过度张扬会直接危及他人和社会的利益,因此,必须对企业牟利之手段进行制约。企业社会责任就是确定企业对社会的责任。从发展过程上看,企业社会责任经历了利己主义、理性主义和伦理主义阶段,从内容上分析,企业社会责任包括经济责任、法律责任和道德责任。探讨企业社会责任的意义在于为企业的行为划定合理的边界。     

教育理论思维的公共性诉求

思维方式深层影响着教育理论研究.从方法论的维度看,公共性的极至崇拜和公共性的完全消解的相异思维方式同时影响着教育理论思维.为避免在两极间徘徊,应寻求一个基于实践的公共的教育理论论域,以基于实践的公共性诉求来理解、探求教育理论,并以爱教育的人间关怀使研究充满活泼的生命力.     

普通师范院校音乐专业教育教学改革初探

普通师范院校音乐教育专业传统办学模式 ,在改革开放的今天 ,已不适应新形势的发展 ,存在着诸多弊端。为了适应我国入世的新形势和配合素质教育 ,本文针对存在的问题 ,提出了一系列教改构想 ,若能有效实施 ,必将为新形势的需要和基础音乐教育培养出新一代高素质的专业人才 ,推进中、小学素质教育向纵深发展     

生物多媒体教学课件的设计与制作

中国加入WTO后 ,民营科技企业面对更加激烈的市场竞争 ,困难和挑战更加严峻。企业制度上的缺陷和不足是制约企业发展的根本因素。从某种意义上说 ,实现制度上的创新和突破比技术创新更为重要。制度创新须解决好两个问题 :一是创新成本问题 ;二是创新与借鉴关系问题。     

On Block Updating in Markov Random Field Models for Disease Mapping

Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components.