基于风险计量指标的证券组合投资的数学模型及其应用

本文建立的证券组合投资的数学模型采用风险系数β作为控制证券投资风险的参数,其经济意义明确,实用性强。该模型应用于证券组合投资,效果明显,操作方便。     

Case–control studies with complex sampling

The use of complex sampling designs in population-based case–control studies is becoming more common, particularly for sampling the control population. This is prompted by all the usual cost and logistical benefits that are conferred by multistage sampling. Complex sampling has often been ignored in analysis but, with the advent of packages like SUDAAN, survey-weighted analyses that take account of the sample design can be carried out routinely. This paper explores this approach and more efficient alternatives, which can also be implemented by using readily available software.     

Heteroscedastic Regression Models and Applications to Off-line Quality Control

We discuss in the present paper the analysis of heteroscedastic regression models and their applications to off-line quality control problems. It is well known that the method of pseudo-likelihood is usually preferred to full maximum likelihood since estimators of the parameters in the regression function obtained are more robust to misspecification of the variance function. Despite its popularity, however, existing theoretical results are difficult to apply and are of limited use in many applications. Using more recent results in estimating equations, we obtain an efficient algorithm for computing the pseudo-likelihood estimator with desirable convergence properties and also derive simple, explicit and easy to apply asymptotic results. These results are used to look in detail at variance minimization in off-line quality control, yielding techniques of inferences for the optimized design parameter. In application of some existing approaches to off-line quality control, such as the dual response methodology, rigorous statistical inference techniques are scarce and difficult to obtain. An example of off-line quality control is presented to discuss the practical aspects involved in the application of the results obtained and to address issues such as data transformation, model building and the optimization of design parameters. The analysis shows very encouraging results, and is seen to be able to unveil some important information not found in previous analyses.     

Subterranean termites in the urban landscape: Understanding their social structure is the key to successfully implementing population management using bait technology

Subterranean termites will likely continue to be major economic insect pests in the urban environment. Public concerns about pesticide use will not abate but continue to drive development and implementation of environmentally more acceptable control strategies for subterranean termites. Termite baits are a promising alternative to soil termiticide treatments for protection of structures, but the correlation between killing termites in the landscape and protecting structures is tenuous given our current understanding of termite biology. We discuss the problems associated with defining the efficacy of termite bait products in regard to determining termite population parameters in the field. This discussion is in the form of six case histories involving measures of termite activity and relatedness taken over a three-year period. Our findings highlight the need to include control populations in studies of termite bait efficacy, the mobility of termite populations over time, the importance of defining the techniques used to describe termite colony associations, and the need to use a multidisciplinary research approach in addressing the question of termite social structure.     

构建企业会计模式的探讨

企业会计模式是对构成企业会计活动的各种要素按照一定逻辑进行综合描述,以反映各要素基本特征及其相互联系的有机整体.国家的经济制度、经济模式和经济发展水平等分别在不同层次上对企业会计模式产生影响.构建企业会计模式需要解决的几个问题包括不同信息使用者之间信息需求的差异,信息客观性与相关性的背离,会计监督机制与内部人控制的矛盾.为了规范企业会计工作,提高会计信息质量,应该从以下几个方面着手建设企业会计模式规范会计管理制度,完善会计信息系统,合理设置会计监督机制.     

管制下的企业行为与绩效分析

自然垄断行业需要政府管制,但受管制企业由于缺乏竞争容易产生低效率的弊端。如何确立自然垄断行业中的政府职能, 政府如何对自然垄断行业进行适度管制以提高其效率已成为国有企业改革进程中的新课题。本文通过对具有竞争结构的国有企业改革过程的考察, 分析了政府管制与企业效益的关系, 通过对市场进入管制下企业行为的描述, 讨论了政府管制对社会福利的影响及可能引发的社会成本。针对政府管制可能产生的低效率情况, 探讨了管制改革的对策及管制改革的效率目标     

浅谈对流动人口的计划生育管理

流动人口计划生育管理是一项重要的、长期而又艰巨的工作。要有效地抓好这一工作,必须紧密依靠人口流出地和流入地的相互配合,建立统一的、有权威的流动人口管理机构,实行凭证管理、归口管理,使这一管理规范化、法制化。同时,注重对流动人口的计划生育教育,发挥他们自我管理的作用。     

高校科研的价值追求

高校科研具有多种价值.但在特定条件下,高校及教师对科研价值的追求,往往容易单一化,这不利于高校提高知识生产率以适应知识经济的需求.作为一个整体,高校科研应重视学术、经济、社会和教育价值的综合研究.单项科研难以兼顾学术价值与社会经济价值,但可以而且应该追求教育价值.为此,在科研管理和教学上采取调控措施是必要的.     

在CAI系统设计中用模糊控制方法设计教学行为

将CAI系统设计的问题归纳为两类 :一类是教学内容的表达和组织 ,另一类是教学行为的设计和运用 ,文中主要将模糊控制方法、面向对象的系统分析技术及教育学理论和实践相结合讨论后者的问题 ,并特别针对课堂教学行为的设计问题提出了一套完整的模型 ,如控制对象、学科知识库、教学经验知识库和模糊推理等等     

I~2C总线与PC机接口设计

介绍一种简单、成本低的 I2 C总线与 PC机的接口卡 ,普通微机便可以与 I2 C系列的外接设备数据传输 ,构成一个工业自动化生产过程的监控系统