股票期权制度在我国的实践研究

随着企业制度改革的推进 ,股票期权制度逐渐成为我国理论界和实务界关注的热点问题 ,出现了大量的关于股票期权理论及其制度设计的研究成果 ,但实证分析其在我国实践效果的却比较少见。本文以上市公司为样本 ,通过对公司经营业绩的实证比较 ,对股票期权的实践效应进行分析 ,并对造成股票期权激励无效的原因进行了一些探讨     

词尾标记-e的消失与英语结构对称性破缺

英语词尾-e的逐渐消亡是语言自身通过放大系统中不对称差异,迫使其低维子系统对称破缺,实际上是依靠概念隐喻以牺牲其结构上的对称美来换取话语的经济效率,用经济的话语表达最充分的信息。而语法化是造成语言内部语法标记和结构渐变的重要原因之一。     

A modified area under the ROC curve and its application to marker selection and classification

The area under the ROC curve (AUC) can be interpreted as the probability that the classification scores of a diseased subject is larger than that of a non-diseased subject for a randomly sampled pair of subjects. From the perspective of classification, we want to find a way to separate two groups as distinctly as possible via AUC. When the difference of the scores of a marker is small, its impact on classification is less important. Thus, a new diagnostic/classification measure based on a modified area under the ROC curve (mAUC) is proposed, which is defined as a weighted sum of two AUCs, where the AUC with the smaller difference is assigned a lower weight, and vice versa. Using mAUC is robust in the sense that mAUC gets larger as AUC gets larger as long as they are not equal. Moreover, in many diagnostic situations, only a specific range of specificity is of interest. Under normal distributions, we show that if the AUCs of two markers are within similar ranges, the larger mAUC implies the larger partial AUC for a given specificity. This property of mAUC will help to identify the marker with the higher partial AUC, even when the AUCs are similar. Two nonparametric estimates of an mAUC and their variances are given. We also suggest the use of mAUC as the objective function for classification, and the use of the gradient Lasso algorithm for classifier construction and marker selection. Application to simulation datasets and real microarray gene expression datasets show that our method finds a linear classifier with a higher ROC curve than some other existing linear classifiers, especially in the range of low false positive rates.     

DNA指纹与性状间的相关度量

根据资料总体分布特征，推导出ＤＮＡ 指纹与两种类型性状间的相关度量公式。论述了使用该公式筛选标记性状指纹的合理性，同时给出了相应的计算和统计分析方法     

被动句中动作主体的助词适用性

日语被动句有多种表现形式,其核心就是动作主体表现的不同.而句子结构、动词的意义、受动者所受的影响及助词「ニ」「力ラ」惯用型「ニヨツテ」本身具有的特质都是决定被动句动作主体表现的因素.真正认识动作主体表现的不同对加深理解被动句的本质有着积极的意义.     

A model for markers and latent health status

We extend the bivariate Wiener process considered by Whitmore and co-workers and model the joint process of a marker and health status. The health status process is assumed to be latent or unobservable. The time to reach the primary end point or failure (death, onset of disease, etc.) is the time when the latent health status process first crosses a failure threshold level. Inferences for the model are based on two kinds of data: censored survival data and marker measurements. Covariates, such as treatment variables, risk factors and base-line conditions, are related to the model parameters through generalized linear regression functions. The model offers a much richer potential for the study of treatment efficacy than do conventional models. Treatment effects can be assessed in terms of their influence on both the failure threshold and the health status process parameters. We derive an explicit formula for the prediction of residual failure times given the current marker level. Also we discuss model validation. This model does not require the proportional hazards assumption and hence can be widely used. To demonstrate the usefulness of the model, we apply the methods in analysing data from the protocol 116a of the AIDS Clinical Trials Group.     

A Bivariate Gamma Model for a Latent Degradation Process

A model is presented in this article based on a bivariate gamma process in which, the first component is latent and determines the failure time and the second represents the marker. This process is a more realistic model for a degradation process. After introducing the model, we obtain failure and survival probability distributions and discuss parametric and predictive inferences based on the Maximum Likelihood method and in a Bayesian setup.     

讲座的语言特征

讲座是一种特殊形式的交际形式,讲座者所使用的语言既不是典型的书面语,也不是典型的口语。本文根据教育部的一位官员在一次教育论坛上的发言,从补救及填充词语、句子结构和语篇连接词语三个方面来分析讲座在语言使用方面的特征。     

市场失灵、政府失效及对策

经济发展史表明,市场经济是一种有效率的经济运行方式。但市场并非完美无缺,种种原因会导致市场失灵的情况发生,从而客观上要求政府发挥其经济职能对市场缺陷进行弥补。而政府在干预经济的过程中也会出现政府失效的情况,因此,必须针对其现象及成因,采取相应的对策。