绿色产品开发投资与供应商渠道侵入策略研究

本文考虑单个供应商和单个零售商组成的供应链,研究了供应商的渠道侵入策略和供应链成员的绿色产品开发（GPD）投资策略。本文首先研究了给定供应商的渠道侵入策略下,供应链成员的GPD最优内生投资决策。然后通过比较不投资策略、零售商投资策略和供应商投资策略下供应链成员的最优利润,得出供应商的最优渠道侵入决策。最后,通过数值实验分析了在不同的策略组合下,消费者绿色敏感度和渠道替代率的变化对零售商和供应商利润的影响。研究发现：1）无论供应商渠道侵入与否,供应商投资GPD可使零售商和供应商的利润达到最高。2）当不投资GPD或零售商投资时,供应商不应该进行渠道侵入;当供应商投资GPD时,如果投资成本较小,或者消费者绿色敏感度较大,那么供应商应该进行渠道侵入。3）基于供应商渠道侵入策略,供应商的绿色投资水平高于零售商的绿色投资水平;基于GPD投资策略,供应商进行渠道侵入后,会提高其绿色投资水平,而零售商则会降低其绿色投资水平。     

两级供应链产品质量控制契约模型分析

基于博弈论和委托代理理论,研究在两级供应链中如何进行质量控制契约设计的问题。建立生产商和购买商的期望收益函数模型,生产商对其生产过程投资水平进行决策并确定其产品质量预防水平;购买商进行质量评价决策并确定其产品质量检验水平。生产商存在降低其生产过程投资水平的道德风险问题,在生产过程中将"削减投资",购买商为激励生产商提高其生产过程投资水平将支付"信息租金"的成本。购买商在进行产品质量检验决策时,存在夸大产品质量缺陷率的道德风险问题,在产品质量检验过程中将"过度检验"。运用最优化原理,求解生产商的最优生产过程投资水平、产品质量预防水平和价格折扣额与购买商的最优质量检验水平和外部损失分摊比例,并进行了算例分析,结果表明:当生产商提高其生产过程投资水平时,其质量预防水平将显著增加,购买商的质量检验水平将显著下降;随着购买商质量检验水平的提高,生产商所提供的价格折扣额先增大后减少,生产商所承担的外部损失分摊比例将会下降,其期望收益增加,购买商的期望收益将会减少,供应链联合期望收益将呈现"倒U"型,求解了期望收益的最大值及各契约参数的值,结果证明所提出的质量控制契约模型是可行的。     

公平偏好下制造商主导型供应链风险传递研究

为研究公平偏好对供应链风险传递的影响，引入公平偏好效用函数，构建制造商主导型供应链风险传递模型，并借助价格弹性系数引申出风险弹性系数，再利用公平偏好矩阵，解决由生产成本波动引起定价与收益风险传递问题。研究表明：制造商公平偏好对定价风险有正向效用，零售商独具公平偏好只对批发价格风险起负向效用却不影响销售价格风险，但制造商公平偏好能促进零售商公平偏好降低销售价格风险；市场规模会弱化公平偏好对定价风险的效用，而价格敏感性则强化该效用；对于收益风险传递提出并证明了一般性结论：收益风险传递与公平偏好无关，只与外部市场有关。数值仿真表明零售商需理性把握公平偏好度以便控制定价风险，而制造商则需要更多地关注公平性，以便于减小定价风险。研究结果对理性权衡收益与风险具有一定的参考价值，对非理性特征下供应链风险管理的良性发展有重要的指导意义。     

考虑公平偏好的零售商主导型供应链均衡决策研究

考虑由具有批发定价权的零售商和生产规模不经济的制造商组成的零售商主导型供应链，构建仅制造商具有公平偏好、仅零售商具有公平偏好，以及双方同时具有公平偏好等三种情形下的Stackelberg博弈模型，探究上下游企业的公平偏好对供应链各成员企业的均衡决策与效用的影响。研究发现：（1）与无公平偏好时的最优产量相比，供应链成员（仅制造商、仅零售商和双方同时）具有公平偏好时制造商将会增加最优产量，提升供应链的运作效率，而且满足特定条件时批发价格契约可以实现供应链的协调。（2）双方同时具有公平偏好对供应链各成员企业的最优决策与效用的影响最为显著。（3）供应链各成员企业的最优决策与效用分别同上下游企业的公平偏好系数之间可能都不是简单的线性关系，具体还与消费者的价格敏感性和制造商的生产成本等因素密切相关。数值分析结果也证实了上述结论。     

客户资产减值与供应商企业投资

高效投资是产业链安全的重要保证,供应链信息溢出效应会导致客户信息对供应商企业投资产生影响。本文运用中国上市公司的供应商企业—客户关系数据,考察了客户资产减值如何影响供应商企业投资。研究发现,客户资产减值会降低供应商企业的投资水平,这验证了客户资产减值在供应链上存在溢出效应。进一步研究发现,客户资产减值通过使供应商企业的管理层产生悲观预期,以及加剧供应商企业的经营风险,进而降低供应商企业的投资水平,但未通过减少信贷资源供给影响供应商企业的投资。此外,对于非国有控股、较弱议价能力、较低行业资产流动性及较高客户媒体关注度的供应商企业,客户资产减值对其投资水平的负向影响更为明显。本文研究结论不仅为客户信息影响上游供应商企业投资提供了经验证据,而且还为监管层规范企业计提资产减值行为,进而提升供应链整体投资效率提供了政策启示。     

考虑不同风险偏好的供应链企业创新投资决策模型

在条件风险值度量准则下,建立了考虑不同风险偏好的供应链创新投资决策模型,并在此基础上分别分析了供应商单独投资和联合投资2种情况下供应链的创新投资水平。给出了联合投资时投资分担比例必须满足的区间,确定了供应商主导和制造商主导下的最优投资分担比例。研究表明:制造商喜好风险可以增加市场中的产品数量,提高供应商创新投资水平;供应商可以通过提升技术创新能力,抵消制造商因为风险规避带来的消极影响。当制造商分担供应商的部分创新投资时,供应商的创新投资水平和制造商的产量均得到了提高,并且供应商主导下确定的最优创新投资分担比例大于制造商主导下确定的最优创新投资分担比例。最后用数值分析验证了模型的有效性。     

基于横向和纵向公平偏好的二层供应链网络均衡决策

在上层为制造商、下层为多个竞争型零售商和需求市场的二层供应链网络中,分析了多个零售商间横向公平偏好、零售商与制造商间纵向公平偏好行为。构建了下层零售商考虑横向和纵向公平偏好的Nash均衡模型,并且得到上层和下层供应链网络的Stackelberg-Nash博弈模型,利用罚函数法求解得到二层供应链网络均衡决策。定性分析了零售商横向、纵向公平偏好权重和纵向公平参考系数对均衡决策的影响,并通过数值算例验证。最后对供应链各决策者给出应对公平偏好负效用的合理化建议。     

渠道模式、努力投入与生鲜农产品供应链运作效率研究

归纳总结我国生鲜农产品供应链三种主要渠道模式的特征和内涵,对比分析不同渠道模式下的生产努力投入、销售努力投入以及供应链效用水平。研究结果表明:(1)农户的风险规避偏好是影响其选择不同渠道模式的关键因素;(2)当农户的风险规避程度较低时,农户应该选择采用自产自销模式,此时的生产努力投入和销售努力投入也较其他模式下更高。而当农户的风险规避程度较高时,加入"农超对接"供应链不仅有利于增进农户效用,而且也能提高生产努力投入和销售努力投入;(3)相比于松散型"农超对接"模式,紧密型"农超对接"模式是一种更优的选择,能够同时提高农户和超市双方的效用水平。     

不同竞合模式下企业研发投资决策及绩效——基于不确定条件的分析

考虑研发不确定条件,在研发阶段可合作,产出阶段产量竞争的两阶段动态博弈下,比较分析了不同竞合模式下,企业的研发决策及所能获得的研发绩效.结果表明,相对于研发竞争,只有溢出效应大时,研发卡特尔下企业才会降低研发门槛值,提高投资水平,同时,企业研发绩效得到增加,竞争研发联盟下企业一定会提高门槛值,降低投资水平,而其研发绩效是不确定的.卡特尔研发联盟优于其他模式,企业研发门槛值最低,投资水平最高,同时可获得最高研发缋效.此外,研发竞争下,溢出增加时企业一定会提升门槛值,降低投资水平,研发绩效可能会增加;研发卡特尔下,溢出增加企业一定会降低研发门槛值,提升投资水平,研发绩效增加.     

竞争供应链中制造商环保技术投资决策研究

本文考虑消费者对质量差异化产品的异质性偏好以及环保意识,建立了消费者效用函数以及产品需求函数,构建了差异化竞争制造商及其零部件供应商之间的动态博弈模型;进而,研究了竞争供应链中制造商环保技术投资策略,考察了市场竞争对供应链均衡定价决策、环保技术投资决策以及消费者福利的影响。研究结果表明：拥有较高技术水平的制造商总是会选择更高的环保技术投资水平,但消费者也需为此支付更高的产品溢价;制造商环保技术投资会影响产品销售价格并有利于提升消费者福利,拥有较高技术水平的制造商总是有动机选择投资环保技术,而技术水平较低的制造商则不会有动机选择投资环保技术;市场竞争会导致供应商和制造商定价决策的变化,但此时供应商反而能够获得更多利润。     

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.     

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.     

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.