委托代理框架下项目投资的最优合同设计

在不确定的市场环境下,企业的投资机会具有期权特点。本文在委托代理框架下,研究实物期权投资中的最优合同设计问题。考虑一个委托代理制的企业,委托人拥有推迟项目投资的期权,授予代理人执行该投资期权。信息不对称下,代理人有隐藏信息转移现金流的动机。为了实现自身利益的最大化,委托人设计合同,在该合同下,代理人将揭示真实的信息。在信息对称与信息不对称的情形下,分别建立实物期权模型,得到了委托人设计的最优合同。并通过数值分析,得到了如下的主要结论,信息不对称下,与信息对称相比,高成本的项目投资时机推迟,低成本的项目时机提前,投资期权价值减少。委托人的期权价值随着审核效率的提高而增大。当代理人越没有耐心时,委托人的期权价值越大。本文的研究为现实中的委托代理框架下的实物期权投资决策提供了一定的指导意义。     

多次投资情况下企业最优容量投资策略研究

与仅考虑一次投资机会情况不同,研究分析了多次投资机会对企业最优容量投资策略的影响,利用实物期权方法建立了企业投资时机和容量选择模型.研究结果表明当拥有较多的投资机会时,企业将会拥有较大的容量投资期权,并会提前实施投资,而且最终投资达到的容量规模也越大.     

非对称信息条件下实物期权最优投资问题研究

描述了实物期权投资者和经营者价值函数,分析了不同信息条件下实物期权的最优投 资决策. 在非对称信息条件下,实物期权经营者对于项目价值信息隐匿,这是一个具有逆向选 择的委托代理问题. 设计了以实物期权投资者利润数学期望最大为目标函数,以投资和数量折 扣作为状态方程的最优控制问题. 应用极大值原理推导了实物期权最优投资和数量折扣的求 解方案. 最后,进行了实物期权最优投资的仿真实验,验证了实物期权在项目投资问题上的分 析结果.     

基于实物期权的项目组合投资决策研究

基于项目投资决策的可延迟性特征,将实物期权的决策灵活性思想引入到企业的投资组合决策中,建立了基于实物期权的0-1整数规划模型.模型以项目的期权价值最大化作为投资组合项目选择的标准,通过项目组合投资时机的灵活安排,实现了项目组合的总投资价值最大化.     

投资时限对项目期权价值的影响分析

针对一般实物期权研究中,项目投资无限期假设的不足,研究实际中对投资时间有限期要求项目的投资期权评价问题.文章以我国房地产投资政策为背景,建立模型,研究给出了对投资机会限定在时间T内有效、投资者在其中具有投资管理柔性的投资项目的价值评价.用数值分析方法讨论了投资时限对投资机会价值和对投资者最优决策的影响,给出了投资者在等待以降低投资风险和尽快投资以避免机会失效之间的权衡.     

不确定环境下自然资源开发项目投资评价模型

以不确定环境下自然资源开发项目投资评价问题为研究对象,以现金收益、开发投资和运营成本的不确定性对投资价值的影响为切入点,在现有实物期权投资评价模型的基础上,同时考虑项目方在投资阶段推迟投资和在生产阶段暂停运营的管理柔性,建立基于多随机变量的自然资源开发项目实物期权投资评价模型． 应用交换型期权和鞅过程等定价理论给出了模型的解析解,并结合某原油开发项目的实例进行了参数的静态分析．     

双重随机不确定条件下的一次性容量扩展投资

考察在未来市场价格和新增容量利用率双重不确定条件下,一次性容量扩展项目投资的最优时机选择问题.应用实物期权的相关理论和方法,建立了一个以投资期权价值最大化为目标函数,以期望第一触点时间为决策变量的项目投资决策模型,并设计了基于Riskoptimizer软件包的仿真优化算法.最后的仿真算例表明了双重随机不确定因素对容量扩展项目最优投资时机选择的定量影响.     

具有技术许可联盟的R＆D投资决策

本文开发了具有技术许可联盟的R&D投资决策模型.考虑了技术许可前后市场结构的变化,利用连续时间阈值自回归过程来模型这一非线性变化的特征,根据实物期权定价理论和博弈理论,给出了R&D投资项目的价值和最优投资规则.通过数值分析讨论了技术许可前后的收益期望增长率和不确定性以及许可合同中竞争者进入市场的时间参数对投资决策的影响.     

基于实物期权理论的矿产资源最优投资策略模型

矿产资源投资周期长、数额大、且不确定性高,应用传统的净现值方法来评估矿产资源投资价值具有很大的局限性。本文运用实物期权理论,通过建立矿产资源最优投资的策略模型,讨论了在矿产品价格以及汇率存在不确定性的情况下,如何对海外矿产资源价值进行评估的问题,并以国内某海外矿产资源项目为例,验证了模型的有效性。研究结果表明,相对于传统的净现值法,实物期权方法可以更好地考虑未来的不确定性对矿产资源项目估值的影响;汇率风险是对海外矿产资源投资的影响很大;矿产资源丰度差异对矿产资源价值的影响很大。     

注册制新股发行定价改革与IPO质量——基于技术创新的视角

文章考虑我国注册制新股发行定价改革构建实物期权模型，得到“窗口指导期”和注册制市场化定价两种情形下创新型企业的最优上市时机和企业价值，探究新股发行定价改革对IPO质量的影响。研究结果表明：注册制新股发行定价改革提高优质创新企业IPO估值，提升优质创新企业的上市积极性，并通过降低优质创新企业等待上市期权成本和上市阈值，激励其较早上市。本文的结论为我国全面推进注册制，提高上市企业质量提供了有益的理论参考。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.