信息披露效果评价模型及其应用研究

探讨了信息披露效果评价的多因素模型 ,给出了一个信息披露效果估价简例 ,提出了信息披露效果的 3种情况及信息效率评价公式。     

Measuring Uncertainty Importance: Investigation and Comparison of Alternative Approaches

Uncertainty importance measures are quantitative tools aiming at identifying the contribution of uncertain inputs to output uncertainty. Their application ranges from food safety (Frey & Patil (2002)) to hurricane losses (Iman et al. (2005a, 2005b)). Results and indications an analyst derives depend on the method selected for the study. In this work, we investigate the assumptions at the basis of various indicator families to discuss the information they convey to the analyst/decisionmaker. We start with nonparametric techniques, and then present variance-based methods. By means of an example we show that output variance does not always reflect a decisionmaker state of knowledge of the inputs. We then examine the use of moment-independent approaches to global sensitivity analysis, i.e., techniques that look at the entire output distribution without a specific reference to its moments. Numerical results demonstrate that both moment-independent and variance-based indicators agree in identifying noninfluential parameters. However, differences in the ranking of the most relevant factors show that inputs that influence variance the most are not necessarily the ones that influence the output uncertainty distribution the most.     

Probabilistic Risk Assessment of Wastes Buried in the Ground

The differences between probabilistic risk assessment (PRA) and safety analysis (SA) are discussed, and it is shown that PRA is more suitable than SA for determining the acceptability of a technology. Since a PRA by the fault tree-event tree analysis method used for reactor safety studies does not seem to be practical for buried waste, an alternative approach is suggested using geochemical analogs. This method is illustrated for the cases of high-level and low-level radioactive waste and for chemical carcinogens released in coal burning.     

Development of a Standard Soil-to-Skin Adherence Probability Density Function for Use in Monte Carlo Analyses of Dermal Exposure

It has recently been suggested that "standard" data distributions for key exposure variables should be developed wherever appropriate for use in probabilistic or "Monte Carlo" exposure analyses. Soil-on-skin adherence estimates represent an ideal candidate for development of a standard data distribution: There are several readily available studies which offer a consistent pattern of reported results, and more importantly, soil adherence to skin is likely to vary little from site-to-site. In this paper, we thoroughly review each of the published soil adherence studies with respect to study design, sampling, and analytical methods, and level of confidence in the reported results. Based on these studies, probability density functions (PDF) of soil adherence values were examined for different age groups and different sampling techniques. The soil adherence PDF developed from adult data was found to resemble closely the soil adherence PDF based on child data in terms of both central tendency (mean = 0.49 and 0.63 mg-soil/cm²-skin, respectively) and 95th percentile values (1.6 and 2.4 mg-soil/cm²-skin, respectively). Accordingly, a single, "standard" PDF is presented based on all data collected for all age groups. This standard PDF is lognormally distributed; the arithmetic mean and standard deviation are 0.52 ± 0.9 mg-soil/cm²-skin. Since our review of the literature indicates that soil adherence under environmental conditions will be minimally influenced by age, sex, soil type, or particle size, this PDF should be considered applicable to all settings. The 50th and 95th percentile values of the standard PDF (0.25 and 1.7 mg-soil/cm²-skin, respectively) are very similar to recent U.S. EPA estimates of "average" and "upper-bound" soil adherence (0.2 and 1.0 mg-soil/cm²-skin, respectively).     

Analysing Competence: Gender and Identity at Work

Competence approaches are among the techniques that claim to measure the behaviour, skills, knowledge and understanding crucial to effective managerial performance. It is claimed that competence approaches empower and develop managers while enabling them to meet organizational objectives. Since the bases for the techniques are avowedly scientific, they are said to provide organizations with a gender neutral form of assessment. In this paper we construct a theoretical framework in terms of which these claims can be analysed and assessed. Using this framework, we examine the competence approach as it has been implemented in six organizations in relation to the claim to objectivity.     

Ecological functions of an impounded marsh and three natural estuarine marshes along Woodbridge River,NY/NJ Harbor

An impounded estuarine marsh scheduled for restoration in 2003 and three nearby unimpounded marshes (Spartina alterniflora, S. patens/Iva frutescens, and Phragmites australis) in highly urbanized NY/NJ Harbor were studied to assess the impact of impoundment on marsh structure and function and to identify trajectories of ecosystem change following removal of the levee. Aboveground biomass was greater in the Phragmites and S. alterniflora marshes (706–809 g/m²) as compared to the S. patens/I. frutescens and impounded marshes (378–588 g/m²). Macro-organic matter (0–30 cm) was similar across all marshes (7452–9212 g/m²). The S. patens/Iva frutescens marsh had the lowest aboveground biomass, but contained more plant species (2.8 species/0.25 m²) and greater species diversity (H = 1.33) than the other marshes (1.3–2.0 species/0.25 m², H = 0.16–0.78). Rates of sediment and nutrient accumulation were lower in the impounded marsh (335 g sediment/m²/yr, 97 g C/m²/yr, 6.5 g N/m²/yr, and 0.9 g P/m²/yr) than in the reference marshes (422–1515 g sediment/m²/yr; 111–160 g C/m²/yr; 7–10 g N/m²/yr; 1.6–2.8 g P/m²/yr). Our results indicate that the impounded marsh does not contain the high species diversity of the high marsh, nor does it provide the same level of functions as naturally inundated marshes. Reintroduction of tidal inundation to the impounded marsh will enhance water quality benefits and favor development of S. alterniflora salt marsh community structure.     

供应链绩效评价系统指标选取的几点思考

供应链绩效评价是供应链管理的重要内容,对确定供应链目标的实现程度和提供决策支持具有重要意义。但是,目前对供应链绩效评价的内容界定还很不完善,缺乏系统性。本文试图对供应链绩效评价体系指标的选取做一些初步的探讨,以加深对供应链绩效评价体系的了解。     

Joint Persistence of Transformation Products in Chemicals Assessment: Case Studies and Uncertainty Analysis

The joint persistence (JP) quantifies the environmental persistence of a parent compound and a selection of relevant transformation products. Here, the importance as well as the uncertainty of the JP in comparison to the persistence of the parent compound alone (primary persistence, PP) are investigated. To demonstrate the effect of transformation products on the environmental persistence of organic chemicals, three case studies of parent compounds (nonylphenol ethoxylates, perchloroethylene, atrazine) and transformation products are investigated in detail with a multimedia fate model. Comparison of the PP and JP values shows that transformation products can significantly increase the persistence. In addition to the point estimates of PP and JP, the associated uncertainties are investigated. For each of the case studies, the chemical-specific input parameters of all compounds are varied and the corresponding variance of the PP and JP is determined by Monte Carlo simulations. Interestingly, the higher number of input parameters required for the JP does not necessarily increase the uncertainty of the JP as compared to that of the PP alone. An exact mathematical expression specifying the contribution of each transformation product to the JP is given. When transformation products are grouped in different generations, it becomes discernible that the first generation increases the JP most; the later generations are of decreasing importance. Finally, the effect of incomplete knowledge of the transformation products and their properties on the JP results is discussed. For reliable JP estimates, knowledge of the first generation transformation products and their degradation rate constants is required.     

论高校英语课程评价的发展趋向

分析了高校英语教学与测试的现状和国际上课程评价的实践,提出并论述了高校英语课程评价的发展趋向--多元化,即评价内容、形式与方法的多元化,评价目标、评价主体和评价时机的多元化.     

关于持续经营的不确定性的探讨

我国会计核算是以持续经营作为假设前提之一。企业间竞争日益激烈 ,研究持续经营的不确定性成为必然。针对“企业普遍来说是持续经营的”潜意识观念 ,提出对持续经营不确定性的评估方法。