中国利率期限结构平滑样条拟合改进研究

在FNZ模型和Waggoner模型的基础上,结合中国国债市场的发展现状,从拟合对象、粗糙度惩罚项的函数形式、参数估计方法、最优化目标函数形式以及估计样本等五方面进行修正和改进,提出利用可变粗糙度惩罚项三次平滑样条改进模型来拟合中国的利率期限结构,并利用上交所国债市场2002年1月1日至2003年12月31日的国债收盘价格数据对该模型进行实证研究.结果发现,笔者提出的改进模型能够较合理、有效地估计较为完整的中国静态利率期限结构.     

利率期限结构估计模型的比较——基于沪深交易所国债

本文沿着数量模型方法的思路,以上海和深圳证券交易所的国债价格为研究对氛利用三次样条函数和NsS模型构造中国国债的利率期限结构,对我国国债利率期限结构进行分析与评价.     

基于B样条函数的上交所利率期限结构估计

本文结合上交所的市场背景,进行了合理的节点设置下,采用B样条函数表示贴现函数、零息票收益曲线和远期瞬时利率曲线等三种方式来估计上交所利率期限结构,并用上交所国债市场的日交易数据对估计进行了样本内和样本外的分组数据拟合优度检验.结果表明:上交所的利率期限结构估计在1～10年期限范围内能够获得可靠的估计,5～7年期限范围内的估计精度最高;在控制数据过拟的前提下,直接估计贴现函数的方式的最适合于上交所利率期限结构的估计.     

国债市场利率期限结构波动的对偶变换建模

本文针对传统利率期限结构拟合曲线存在过度波动问题,构建定价误差绝对距离和波动曲率双重最优化模型,借助对偶几何程序转换为在线性约束区域内的绝对距离最小化问题,并运用负指数平滑立方L1样条和计算几何逼近算法求解模型参数,通过负指数立方L1样条、NSS模型和B样条进行样本内拟合与样本外预测能力的比较,证实负指数立方L1平滑样条对利率期限结构波动的定价精确度、结构性拟合和样本外预测能力均有明显的优势,丰富了国债市场利率期限结构波动与定价的理论基础和研究方法。     

基于利率期限结构模型的中国可转换债券定价分析

选取上海证券交易所国债,基于样条函数模型推导出无违约利率期限结构,进行有效性检验;选取上海证券交易所可转换债券推导出违约利率期限结构,并与无违约利率期限结构对可转换债券的定价效果进行比较;针对目前国内可转换债券定价均假设利率恒定、没有考虑利率变化的现状,将无违约利率期限结构与Black-Scholes期权定价模型相结合,提出了可转债定价的一般模型,并用此模型对歌华转债进行定价实证分析,结果表明,两者均存在一定的偏差,可见利率期限结构模型对中国可转换债券定价相对有效.     

基于利率期限结构和博弈论的R&D投资决策分析

阐述了实物期权的基本原理和亚式期权的内涵及定价求解;基于样条函数模型,从上海证券交易所国债市场和企业债券市场分别推导出无违约利率期限结构和违约利率期限结构,用国债市场的无违约利率作为无风险利率,用企业债券市场的含违约风险的利率作为折现率,并将亚式期权和博弈论结合起来,分析了双寡头市场结构下的R&D投资决策分析.     

国债利率期限结构拟合模型及在金融中的应用

众所周知,利率是经济和金融领域的一个核心变量,它实质上是资金的价格,反映了资金的供求关系。随着中国国债市场的发展和利率市场化的改革深入,研究国债的利率期限结构,为资金市场提供有普遍参考价值的利率,从而为市场上的各种利率产品进行定价以及进行利率市场风险管理是我国的重要研究课题,而国债利率期限结构的估计又是研究国债利率期限结构的根本,也就是如何从国债的市场价格信息中的构造出利率和到期期限的关系。     

基于利率期限结构和博弈论的R＆D投资决策分析

阐述了实物期权的基本原理和亚式期权的内涵及定价求解;基于样条函数模型,从上海证券交易所国债市场和企业债券市场分别推导出无违约利率期限结构和违约利率期限结构,用国债市场的无违约利率作为无风险利率,用企业债券市场的含违约风险的利率作为折现率,并将亚式期权和博弈论结合起来,分析了双寡头市场结构下的R&D投资决策分析.     

货币政策调整对交易所国债收益率的影响分析

为研究货币政策工具对国债市场的影响,采用NSM模型构建国债利率期限结构,应用事件分析法对关键期限的收益率进行研究。研究结果对宏观调控中货币政策的应用具有重要的参考价值;结合收益率曲线变化,对债券投资策略调整也具有重要的意义。     

卡尔曼滤波法模拟和预测沪市国债期限结构

以多因素CIR为基础,运用卡尔曼滤波模拟和估计沪市国债利率的期限结构.卡尔曼滤波方法可有效处理不可观察的向量(状态向量),能综合多因素CIR模型的时间序列特性和横截面信息,可以充分利用可获得的期限结构的其他各种信息.采用的国债利率为用息票剥离方法得到的零息票利率,原始数据为1997年6月27日～2003年2月25日期间交易所的国债现货和国债回购的周交易价格数据,源自中国国债网.多因素模型能很好地刻画收益率曲线的动态变化,统计结果支持四因素CIR模型.实证发现,中国国债期限结构先升后降、而后再次升降,呈明显的驼峰状;长期利率与短期利率差距不大,收益率期限结构扭曲.这也表明合理的国债利率期限结构的确尚未形成.     

Criteria for selecting a production control philosophy

Logistic objectives constitute a compromise between having short leadtimes and a low volume of work in progress on the one hand and a high resource loading and due date obligation on the other. Miscellaneous production planning approaches offered today provide different combinations of logistic objectives for satisfying a manufacturing strategy. To combine the strength of the various approaches into a unified system, a new approach based on a dynamic and distributed production planning methodology is proposed. To customize the approach, various analyses and specifications have to be made and for that reason some important characteristics and criteria for analysing production control philosophies will be given.     

The social construction of the meaning of acute stressors: a qualitative study of the personal accounts of police officers using a stress counselling service

The police profession is one in which acute stressors are encountered more frequently than in other occupations. Using the personal accounts of 35 police officers attending an in-house stress counselling clinic, the aim of the present study was to provide a qualitative examination of how the institutional context of policing influenced the ways in which acute stressors signified to individual police officers experiencing felt distress. Using the framework of Rational Emotive Behaviour Therapy as an analytical tool, it is argued that beliefs contributing to the experience of felt distress are related to the way in which policing as both an identity and an activity is constructed through the police organizational culture. Not only do these constructions influence the ways in which officers perceive themselves and their environments, but they also operate at the collective level to 'normalize' some emotional responses and to 'pathologize' others which, it is argued, could impact upon the outcomes of interventions such as stress counselling.     

The moderating role of social support in Karasek's job strain model

This paper examines whether social support is a boundary-determining criterion in the job strain model of Karasek (1979). The particular focus is the extent to which different sources of social support, work overload and task control influence job satisfaction, depersonalization and supervisor assessments of work performance. Hypotheses are tested using prospective survey data from 80 clerical staff in a university setting. Results revealed 3-way interactions among levels of support (supervisor, co-worker, non-work), perceived task control and work overload on levels of work performance and employee adjustment (self-report). After controlling for levels of negative affect in all analyses, there was evidence that high levels of supervisor support mitigated against the negative effects of high strain jobs on levels of job satisfaction and reduced reported levels of depersonalization. Moreover, high levels of non-work support and co-worker support also mitigated against the negative effects of high strain jobs on levels of work performance. The results are discussed in terms of the importance of social support networks both at, and beyond, the work context.     

Job insecurity, coping resources and personality dispositions in occupational strain

This paper presents research on the relationships between the work-related stressor of perceived job insecurity and various indicators of occupational strain, taking into account employees' personality dispositions (trait negative and positive affectivity) and coping resources. Respondents were 222 Australian public servants surveyed during organizational restructuring that involved downsizing and threat to job certainty. The research was formulated within an adaptation of Osipow, Doty, and Spokane's (1985) framework of stress-strain-coping that included the possible direct as well as moderating effects of personality dispositions in reporting occupational strain (Parkes, 1990). Findings from hierarchical regression analyses indicate consistent significant independent effects of personality dispositions, coping resources and perceived job insecurity on various indicators of strain. There was also support for the moderating roles of negative affectivity and self-care in the relation between perceived job insecurity and physical strain. Implications for the role of dispositional factors, especially negative affectivity, and the utility of various coping resources in accounting for occupational strain in times of threatened job security are discussed.     

Introduction to Special Section on Sensitivity Analysis and Summary of NCSU/USDA Workshop on Sensitivity Analysis

This guest editorial is a summary of the NCSU/USDA Workshop on Sensitivity Analysis held June 11–12, 2001 at North Carolina State University and sponsored by the U.S. Department of Agriculture's Office of Risk Assessment and Cost Benefit Analysis. The objective of the workshop was to learn across disciplines in identifying, evaluating, and recommending sensitivity analysis methods and practices for application to food‐safety process risk models. The workshop included presentations regarding the Hazard Assessment and Critical Control Points (HACCP) framework used in food‐safety risk assessment, a survey of sensitivity analysis methods, invited white papers on sensitivity analysis, and invited case studies regarding risk assessment of microbial pathogens in food. Based on the sharing of interdisciplinary information represented by the presentations, the workshop participants, divided into breakout sessions, responded to three trigger questions: What are the key criteria for sensitivity analysis methods applied to food‐safety risk assessment? What sensitivity analysis methods are most promising for application to food safety and risk assessment? and What are the key needs for implementation and demonstration of such methods? The workshop produced agreement regarding key criteria for sensitivity analysis methods and the need to use two or more methods to try to obtain robust insights. Recommendations were made regarding a guideline document to assist practitioners in selecting, applying, interpreting, and reporting the results of sensitivity analysis.     

Job stress, job strain, and psychological withdrawal among Dutch university staff: towards a dualprocess model for the effects of occupational stress

This study examined the antecedents of job strain (emotional exhaustion, health complaints) and withdrawal behaviour (e.g. lowered organizational commitment) among a cross-sectional sample of 131 academic staff members of the law department of a large Dutch university. Conservation of resources theory (Hobfoll, 1989) provided the theoretical background for this study. Strains and withdrawal behaviours were expected to be most prominent among those who reported having few resources and/or who reported high job demands. Structural equation modelling revealed that this was indeed the case. As predicted, differential patterns of effects emerged for job demands and job resources. Analysis of the effects of four job-specific stressors revealed that especially the structural aspects of a staff member's teaching task (e.g. the number of students in their classes) contributed strongly to perceived job demands. Theoretical and practical implications of the study are discussed.     

Dermal Uptake of 18 Dilute Aqueous Chemicals: In Vivo Disappearance‐Method Measures Greatly Exceed In Vitro‐Based Predictions

Average rates of total dermal uptake (K_up) from short‐term (e.g., bathing) contact with dilute aqueous organic chemicals (DAOCs) are typically estimated from steady‐state in vitro diffusion‐cell measures of chemical permeability (K_p) through skin into receptor solution. Widely used (“PCR‐vitro”) methods estimate K_up by applying diffusion theory to increase K_p predictions made by a physico‐chemical regression (PCR) model that was fit to a large set of K_p measures. Here, K_up predictions for 18 DAOCs made by three PCR‐vitro models (EPA, NIOSH, and MH) were compared to previous in vivo measures obtained by methods unlikely to underestimate K_up. A new PCR model fit to all 18 measures is accurate to within approximately threefold (r = 0.91, p < 10^?5), but the PCR‐vitro predictions (r > 0.63) all tend to underestimate the K_up measures by mean factors (UF, and p value for testing UF = 1) of 10 (EPA, p < 10^?6), 11 (NIOSH, p < 10^?8), and 6.2 (MH, p = 0.018). For all three PCR‐vitro models, log(UF) correlates negatively with molecular weight (r² = 0.31 to 0.84, p = 0.017 to < 10^?6) but not with log(vapor pressure) as an additional predictor (p > 0.05), so vapor pressure appears not to explain the significant in vivo/PCR‐vitro discrepancy. Until this discrepancy is explained, careful in vivo measures of K_up should be obtained for more chemicals, the expanded in vivo database should be compared to in vitro‐based predictions, and in vivo data should be considered in assessing aqueous dermal exposure and its uncertainty.     

Systems Resilience for Multihazard Environments: Definition,Metrics, and Valuation for Decision Making

The United Nations Office for Disaster Risk Reduction reported that the 2011 natural disasters, including the earthquake and tsunami that struck Japan, resulted in $366 billion in direct damages and 29,782 fatalities worldwide. Storms and floods accounted for up to 70% of the 302 natural disasters worldwide in 2011, with earthquakes producing the greatest number of fatalities. Average annual losses in the United States amount to about $55 billion. Enhancing community and system resilience could lead to massive savings through risk reduction and expeditious recovery. The rational management of such reduction and recovery is facilitated by an appropriate definition of resilience and associated metrics. In this article, a resilience definition is provided that meets a set of requirements with clear relationships to the metrics of the relevant abstract notions of reliability and risk. Those metrics also meet logically consistent requirements drawn from measure theory, and provide a sound basis for the development of effective decision‐making tools for multihazard environments. Improving the resiliency of a system to meet target levels requires the examination of system enhancement alternatives in economic terms, within a decision‐making framework. Relevant decision analysis methods would typically require the examination of resilience based on its valuation by society at large. The article provides methods for valuation and benefit‐cost analysis based on concepts from risk analysis and management.     

Distinguishing traumatic, vicarious and routine operational stressor exposure and attendant adverse consequences in a sample of police officers

Problems in studying occupational stress within the police service are identified and the paucity of work on operational duties as potential stressors are discussed. The present study reports the results of a factor analysis of operational stressors (N = 601 serving British police officers) that revealed three factors: exposure to death and disaster; violence and injury; sexual crime. These were demonstrated to be reliable scales and were included in logistic regression models together with a range of demographic and psychological variables. Models were applied to men and women separately, which showed there to be different predictors of the likelihood of suffering distress (measured by the General Health Questionnaire, GHQ) in terms of the officer's gender and operational role. Overall the model for women officers was better at predicting psychological distress than that for men. These findings are related to aspects of the police occupational culture. Further discussion is offered that conceptualizes police operational stressors as traumatic, routine and vicarious. Finally, some implications are drawn for the provision of stress intervention in the light of this differentiation.     

UNIX系统性能监控简述及shell系统资源统计程序

本文简要阐述了unix系统中(主要以IBM的AIX为例)进行系统性能管理的几种命令行工具,并通过编写shell实例程序,运用其中提到的工具实现系统资源利用率的统计程序,为做好unix系统管理和调优提供参考.