短期利率跳跃-扩散模型的非参数门限估计

跳跃行为是短期利率动态过程的一个重要特征,跳跃-扩散模型能更好的描述短期利率行为。本文应用非参数门限估计对短期利率的跳跃-扩散模型进行了仿真实验和实证分析。仿真实验表明,门限估计能有效消除传统非参数估计对跳跃-扩散模型的估计偏差,估计参数具有无偏性。对上海银行间同业拆借利率(Shibor)的实证分析发现,门限估计有效探测到了短期Shibor的跳跃行为,且这种跳跃行为和宏微观的经济金融现象相一致。最后和扩散模型的实证比较得到,基于门限估计的跳跃-扩散模型对短期利率分布的偏度和峰度的拟合能力更优。     

基于跳跃-扩散利率模型的浮动利率抵押贷款支持证券定价研究

已有文献在研究抵押贷款支持证券的定价时,所假设的利率随机过程大多是连续的,没有考虑到利率受人为或突发事件的干扰而产生跳跃不连续的情形.本文利用跳跃-扩散模型模拟利率随机过程,结合我国借款人行为特点建立提前偿还比例危险模型,运用Monte Carlo模拟方法,研究了浮动利率抵押贷款支持证券的定价,讨论了利率模型各参数的变化对定价的影响.经模拟发现:利率跳跃的频率、跳跃幅度的波动越大,证券价格越大,而利率跳跃幅度的均值越大,证券价格却越小.     

我国银行间同业拆借利率的动态研究——基于跳跃-扩散-机制转换模型的实证分析

针对我国短期利率易受政策影响,波动较大并存在结构变化等特点,构建了跳跃-扩散-机制转换模型,同时考察了银行间7天同业拆借利率的波动、跳跃和结构变化三种效应,发现我国同业拆借利率不仅具有均值回归特性而且还存在明显的跳跃与机制转换,并且该模型比其嵌套的受限模型表现更佳.在高波动状态下利率波动的水平效应和ARCH效应可以忽略...     

包含Jump-Arch过程的利率模型及其应用

从4个方面对比分析了 Jump-Arch 扩散模型、跳跃扩散模型、Arch 扩散模型和扩散模型,发现 Jump-Arch 扩散模型是研究中的最优模型,它在解释和预测利率的波动方面表现出很强的能力,跳跃不仅是利率均值回复的来源,也是利率波动的最主要来源,因此对利率动态行为的描述必须考虑跳跃过程.同时研究发现,R091国债回购市场波动存在明显的"周一"和"周五效应",并利用 Jump-Arch 扩散模型解释了出现这种异象的原因.     

基于跳跃-扩散过程的煤炭资源采矿权估价三因素模型

煤炭资源采矿权可以被认为是一个多期多阶段的复合看涨期权,煤炭价格、便利收益和利率的随机波动都对煤炭资源采矿权价值有较大的影响。基于期权理论,构建了煤炭价格服从跳跃-扩散过程,利率和便利收益服从均值回复过程的煤炭资源采矿权估价三因素模型。实例运用表明,该模型较单因素模型、双因素模型更能体现资源所有者的权益。随着采矿权有效期的临近,关于利率、便利收益、煤炭开采成本和煤炭价格的信息趋于透明,这些因素的变动对采矿权的影响逐渐减弱。     

我国银行间同业拆借利率的动态研究———基于跳跃 扩散 机制转换模型的实证分析

针对我国短期利率易受政策影响,波动较大并存在结构变化等特点,构建了跳跃 扩散 机制转换模型,同时考察了银行间 7 天同业拆借利率的波动、跳跃和结构变化三种效应,发现我国同业拆借利率不仅具有均值回归特性而且还存在明显的跳跃与机制转换,并且该模型 比其嵌套的受限模型表现更佳． 在高波动状态下利率波动的水平效应和 ARCH 效应可以忽略; 低波动状态下,水平效应可以忽略． 另外,跳跃具有聚类效应,高( 低) 的跳跃概率和高( 低)状态概率对应着高( 低) 利率和较高( 低) 的波动率,跳跃主要发生在高状态机制下,低状态机 制下发生跳跃的可能性很小．     

利率带有跳跃情形下的信用衍生品定价研究

考虑作为风险因素的利率的跳跃,以研究信用衍生品的定价问题.通过影响信用衍生品参考债务实体违约概率相应的违约强度,利率的跳跃对信用衍生品的定价将产生影响.为此,令描述各个状态变量变化的随机过程是交叉激励的,以体现各事件之间的依赖关系.在线性—二次跳跃—扩散框架下给出了一般定价模型,并可通过Riccati方程组对其进行求解.最后,在特定的随机过程下,将所得定价模型应用在CDS上,并给出定价公式的显性表达式,以作举例.     

基于时变跳跃次数的基准利率风险测算研究

各国央行包括美联储的利率调整和变动就是基准利率风险.基准利率的变化势必要导致金融资产定价的变动和风险溢价.本文通过自回归模型AR测算随时间变化的利率跳跃次数,确定基准利率跳跃的概率,利用伽马分布和正态分布分别测算基准利率跳跃的时间与幅度,根据利率跳跃的概率、时间和幅度确定基准利率跳跃风险溢价,建立基于时变跳跃次数的基准利率跳跃风险溢价测算模型,并利用中国上海证券交易所国债7天回购利率数据进行实证研究.本文创新与特色:1)通过自回归模型AR测算时变的利率跳跃次数,测算利率发生跳跃的概率,确定基准利率跳跃风险溢价,揭示跳跃次数的动态变化规律,反映历史利率跳跃行为对未来利率跳跃行为的影响,改变现有研究以常数跳跃次数测算利率跳跃概率、无法真实反映利率跳跃的频繁程度,导致利率跳跃概率及利率跳跃风险溢价测算不准的弊端.2)研究表明,现有研究的常数跳跃次数仅仅是本文跳跃次数测算模型在参数ρ、γ等于0时的特例.3)通过利率跳跃的概率、时间和幅度确定基准利率的跳跃风险溢价,解决基准利率跳跃风险补偿的测算问题.     

HJM框架下基于CPI的期限结构模型及其应用

通过假设实际远期利率、名义远期利率及通货膨胀指数所服从的扩散过程的波动项分别为二维、二维和三维布朗运动,建立了基于CPI的无套利期限结构模型,探讨了无套利期限结构与等价鞅测度之间的关系,并得到三因子利率期限结构变化的微分方程.最后推导出了基于CPI指数的欧式期权价格的解析解.     

基于动态跳跃的中国短期利率研究:1997—2010

短期利率研究对固定收益定价和风险管理具有重要意义.把GARCH-Jump及其动态扩展形式引入到VASICEK短期利率模型中,拟合了中国的短期利率过程,检验了理性投资者人假说.实证结果表明:中国的短期利率过程不仅存在GARCH波动,还存在动态的跳跃波动因素;非参数检验表明以贝叶斯决策过程为设定条件的动态跳跃模型,对短期利率拟合得更好,并且预测能力更优,从而验证了中国短期利率市场的投资者在应对异常事件时采取贝叶斯理性决策法则;短期利率跳跃模型对投机和宏观信息冲击有一定的解释能力.     

Power,authority and legitimacy

Management, human resources, organization, control, leadership, etc., all seem to be just so many euphemisms for power, and this suggests a discourse of management and organization that calls things by their proper name. This paper on the contrary stresses the need to resolve the concept of ‘power’ itself into more differentiated notions, and proposes that clarification may be derived from distinctions once explicit in the vocabulary of Classical antiquity, but lost in modern European languages. It argues that nothing but confusion in thinking about organizations, management and legitimation can result from the failure to recognize that the phenomena this vocabulary identifies and distinguishes are irreducibly different.     

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.     

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.     

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.