On equilibrium in resource markets with scale economies and stochastic prices

In this paper, I show the existence and the characteristics of equilibrium in a non-renewable resource market where extraction costs are non-convex and market price is subject to stochastic shocks, an empirically relevant setting. In my model firms may be motivated to hold inventories to facilitate production smoothing, which allows them to continue producing at a smooth pace at any instant when extraction ceases, e.g. when reserves are exhausted. This aspect of the model then supports a competitive equilibrium in the presence of non-convex costs. Casual empirical evidence is provided that supports the central features of my model for a variety of non-renewable resources, lending credence to the explanation for equilibrium I propose.     

The employee as a punching bag: The effect of multiple sources of incivility on employee withdrawal behavior and sales performance

The link between the interpersonal stressor of workplace mistreatment and objective measures of performance is often overlooked in organizational research. In order to fill this research gap, we examined the unique and combined effects of two sources of incivility (customer and coworker) on objective sales performance and withdrawal behaviors (absenteeism and tardiness). We hypothesized that coworker and customer incivility would interact to predict reduced performance and increased withdrawal, using the conservation of resources model to support our hypotheses. We surveyed 120 bank tellers regarding experienced incivility and obtained performance and withdrawal data spanning a period of several months following the survey. The data indicated that coworker and customer incivility did interact to predict decreased sales performance and increased absenteeism, supporting the majority of our proposed hypotheses. Theoretical and practical implications of the findings and future directions are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

基于动态风险平衡的海洋平台事故连锁风险研究

针对海洋平台事故风险特点,提出动态风险平衡概念,以此建立事故动力模型,并将该模型运用到墨西哥湾"深水地平线"井喷事故。动态风险平衡表征事故动力与事故阻力之间的动态平衡状态,具有动态性和暂时稳定性。事故动力模型以海洋平台可能发生的重大事故为研究对象,从工艺、技术和管理等角度分析事故可能致因和事故发展可能影响因素。该模型首先分析对象的初始事故动力,建立事故连锁风险图,然后计算初始动力发生情况下,传递动力和传递阻力的概率分布,最后提出相应风险控制措施。实例分析表明,基于动态风险平衡建立的事故动力模型能有效分析海洋平台事故连锁风险。     

考虑优先权的人群安全疏散动态模型

为制定合理、高效的应急状况下建筑物内人群疏散方案,考虑拥堵对人流速度的影响及疏散中不同人员特点,对建筑物内人群疏散动态实时分配问题进行研究。首先,采用元胞传输理论将建筑物内复杂的结构转化为元胞—连接桥路网模型,进而以最短疏散时间为目标函数、元胞流量守恒和流量传播为约束条件建立线性优化模型。通过对模型的求解可以得到不同优先级人员的网络清空时间、各路段实时人员数量及路径选择最优方案。案例分析结果表明,疏散过程中人员的优先级差异以及拥堵的发生均会影响不同人员的网络清空时间,因此,针对建筑物内人群疏散进行建模时,应考虑以上因素。     

基于SEM的建筑企业安全文化绩效形成机制研究

为探讨工程项目情境下建筑企业安全文化构成及其形成绩效机制,基于扎根理论,提出安全文化包含物质、制度、观念及情境4部分,依此构建其与安全绩效因果关系的结构方程模型(SEM),运用软件AMOS7.0对问卷调查所得数据进行分析并对模型进行验证。结果表明,安全情境文化对安全结果产生持续、微弱的负向影响;安全观念文化对安全结果产生较大间接影响;而安全制度文化和物质文化对安全结果的影响都有直接和间接影响(通过影响安全行为最终影响结果)2方面,并据此提出持续改进情境文化、综合采用行为管理方法与非行为管理方法的建议。     

地震灾害紧急救援队优化救援装备配备分析

本文通过对汶川、日本大地震等国内外地震救援经验教训、地震灾害紧急救援队的任务性质、建筑物结构、废墟倒塌类型和环境影响因素的分析,提出了优化地震救援装备配备建议,以便有效的发挥地震救援装备的应用能力。     

防刺防弹复合材料的技术状况探讨

本文论述了防弹防刺复合材料的国内外发展状况、目前国内外所普遍采用的防刺防弹材料状况、防弹防刺复合材料所采用的材料状况、防弹防刺复合材料工艺状况、防弹防刺复合材料结构状况、防弹防刺复合材料的测试技术状况、防弹防刺复合材料的性能状况。     

应用高效离子交换色谱分析青枯菌的致病力分

应用高效离子交换色谱和激光光散射仪检测器对不同致病力的青枯菌进行分析,建立了一种快速检测青枯菌致病力分化的新方法青枯菌纯培养物经过高效离子交换色谱分离得到3个致病力不同的特征峰,大小依次为峰3组分>峰2组分>峰1组分.对10株青枯菌进行色谱分析,并结合番茄组培苗感染试验检测其致病力,结果发现,强致病力菌株经过色谱分离只在峰3的保留时间位置出现单一特征峰,在9 d内即可引起100%的番茄组培苗发病;若菌株经过色谱分离形成3个特征峰,则峰3所占的面积比越大,该菌株的致病性相对就越强.25株不同致病力青枯菌的验证试验表明了该方法的可行性,番茄组培苗发病率x与峰3面积比y之间呈现出良好的线性关系,回归方程y=0.9581x+5.4984,相关系数r=0.986.通过对青枯菌色谱行为、致病力、细胞表而黏附的EPS Ⅰ含量三者之间相互关系的进一步研究,发现青枯菌的致病力越强,则细胞表面黏附的EPSⅠ越多,峰3所占的面积比就越大.图3表6参15     

Risk aversion and adaptive management: Insights from a multi-armed bandit model of invasive species risk

This article explores adaptive management (AM) for decision-making under environmental uncertainty. In the context of targeting invasive species inspections of agricultural imports, I find that risk aversion increases the relative value of AM and can increase the rate of exploratory action. While calls for AM in natural resource management are common, many analyses have identified modest gains from this approach. I analytically and numerically examine the distribution of outcomes from AM under risk neutrality and risk aversion. The inspection decision is framed as a multi-armed bandit problem and solved using the Lagrangian decomposition method. Results show that even when expected gains are modest, asymmetry in the distribution of outcomes has important implications. Notably, AM can serve to buffer against large losses, even if the most likely outcome is a small loss.     

Influence of eco-innovation on Indian manufacturing sector sustainable performance

Manufacturing firms are striving to improve their sustainable performance in order to satisfy multiple stakeholders. Eco-innovation is a promising approach that decreases environmental impact and helps firms to increase their business value. There are several antecedents which help the firms to innovate and improve their triple bottom line performance. Among the antecedents, management and innovative practices are directly related to eco-innovation. It is not well known what practices and innovations help the firms to eco-innovate as well as to improve sustainable performance. Hence, the research objective of this paper is to identify the suitable combination of management and innovative practices that help firms to eco-innovate as well as to achieve overall sustainable performance. The paper develops an eco-innovation conceptual model which relates the management and innovative practices (antecedents) and overall sustainable performance (consequences) of eco-innovation using institutional theory. Using Indian manufacturing sector’s empirical data and Structural Equation Modelling (SEM) approach, this paper determines the effect of eco-innovation’s antecedents and consequences. In the Indian context, this study suggests that the role of management practice is more significant towards eco-innovation than innovative practices. The results reflect practitioners’ view on how to increase innovation rate and to focus more on social aspects. The finding suggests that training on environmental related practices could tackle innovation and social aspects in the Indian manufacturing sector context.