基于再制造闭环供应链视角的低碳减排研究     

史成东 《科技管理研究》2018,(10)

以一个销售商驱动的低碳再制造闭环供应链为研究对象,用均值-方差刻画风险特性,分析研究低碳产品市场和废旧低碳产品市场均为随机市场需求情境下、零和博弈和集中决策下闭环供应链中,低碳产品销售价、交易价格、低碳废旧产品回收价格等变量和节点企业期望效用及整个链条期望效用的变化规律。研究表明:零和博弈下低碳闭环供应链未能实现优化和协调。最后,设计正向渠道收益共享、逆向渠道风险共担契约,实现低碳再制造闭环供应链的协调,并通过数值仿真和灵敏度分析验证该模型的有效性及实用性。  相似文献   

Bayesian reasoning in avalanche terrain: a theoretical investigation     

Philip A. Ebert 《Journal of Adventure Education & Outdoor Learning》2019,19(1):84-95

In this article, I explore a Bayesian approach to avalanche decision-making. I motivate this perspective by highlighting a version of the base-rate fallacy and show that a similar pattern applies to decision-making in avalanche-terrain. I then draw out three theoretical lessons from adopting a Bayesian approach and discuss these lessons critically. Lastly, I highlight a number of challenges for avalanche educators when incorporating the Bayesian perspective in their curriculum.  相似文献   

Workload and non-contact injury incidence in elite football players competing in European leagues     

Barthelemy Delecroix  Alan McCall  Brian Dawson  Serge Berthoin 《European Journal of Sport Science》2018,18(9):1280-1287

Purpose: The aim of this study was to analyse the relationship between absolute and acute:chronic workload ratios and non-contact injury incidence in professional football players and to assess their predictive ability. Methods: Elite football players (n?=?130) from five teams competing in European domestic and confederation level competitions were followed during one full competitive season. Non-contact injuries were recorded and using session rate of perceived exertion (s-RPE) internal absolute workload and acute:chronic (A:C) workload ratios (4-weeks, 3-weeks, 2-weeks and week-to-week) were calculated using a rolling days method. Results: The relative risk (RR) of non-contact injury was increased (RR?=?1.59, CI95%: 1.18–2.15) when a cumulative 4-week absolute workload was greater than 10629 arbitrary units (AU) in comparison with a workload between 3745 and 10628?AU. When the 3-week absolute workload was more than 8319?AU versus between 2822 and 8318?AU injury risk was also increased (RR=?1.46, CI95% 1.08–1.98). Injury incidence was higher when the 4-week A:C ratio was <0.85 versus >0.85 (RR?=?1.31, CI95%: 1.02–1.70) and with a 3-week A:C ratio >1.30 versus <1.30 (RR?=?1.37, CI95%: 1.05–1.77). Importantly, none of the A:C workload combinations showed high sensitivity or specificity. Conclusions: In elite European footballers, using internal workload (sRPE) revealed that cumulative workloads over 3 and 4 weeks were associated with injury incidence. Additionally, A:C workloads, using combinations of 2, 3 and 4 weeks as the C workloads were also associated with increased injury risk. No A:C workload combination was appropriate to predict injury.  相似文献   

Sport-specific biomechanical responses to an ACL injury prevention programme: A randomised controlled trial     

Jeffrey B. Taylor  Kevin R. Ford  Randy J. Schmitz  Scott E. Ross  Terry A. Ackerman  Sandra J. Shultz 《Journal of sports sciences》2018,36(21):2492-2501

Anterior cruciate ligament (ACL) injury prevention programmes have not been as successful at reducing injury rates in women’s basketball as in soccer. This randomised controlled trial (ClinicalTrials.gov #NCT02530333) compared biomechanical adaptations in basketball and soccer players during jump-landing activities after an ACL injury prevention programme. Eighty-seven athletes were cluster randomised into intervention (6-week programme) and control groups. Three-dimensional biomechanical analyses of drop vertical jump (DVJ), double- (SAG-DL) and single-leg (SAG-SL) sagittal, and double- (FRONT-DL) and single-leg (FRONT-SL) frontal plane jump landing tasks were tested before and after the intervention. Peak angles, excursions, and joint moments were analysed using two-way MANCOVAs of post-test scores while controlling for pre-test scores. During SAG-SL the basketball intervention group exhibited increased peak knee abduction angles (p = .004) and excursions (p = .003) compared to the basketball control group (p = .01) and soccer intervention group (p = .01). During FRONT-SL, the basketball intervention group exhibited greater knee flexion excursion after training than the control group (p = .01), but not the soccer intervention group (p = .11). Although women’s soccer players exhibit greater improvements in knee abduction kinematics than basketball players, these athletes largely exhibit similar biomechanical adaptations to ACL injury prevention programmes.  相似文献   

电网项目海外投资案例研究与风险识别     

郭莉  王朋  方向  张旺 《科技管理研究》2018,(18)

在分析电网项目海外投资现状的基础上,以两个典型的电网海外投资项目为例,分析和梳理在投资过程中潜在风险因素,并结合现有相关文献,构建电网项目海外投资风险指标体系。在此基础上面向电网海外投资专家和相关研究人员,针对风险的发生可能性、造成损失水平和可控制性等三方面进行问卷调查及统计分析工作,风险水平的计算引入脆弱性理论,进而明确各风险因素的重要性排序,为电网项目海外投资过程中的风险管理提供一定的参考意义。  相似文献   

Institutional shaping of research priorities: A case study on avian influenza     

Matthew L. Wallace  Ismael Ràfols 《Research Policy》2018,47(10):1975-1989

Since outbreaks in 2003, avian influenza has received a considerable amount of funding and become a controversial science policy issue in various respects. Like in many other global and multidisciplinary societal problems fraught with high levels of uncertainty, a variety of perspectives have emerged over how to “tackle” avian influenza and public voices have expressed concern over how research funds are being allocated. In this article, we document if and how research agendas are being informed by public policy debates. We use qualitative and quantitative approaches to examine the relations between expectations of outcomes of public science and the existing research landscape. Interviews with a cross-section of stakeholders reveal a wide range of perspectives and values associated with the nature and objectives of existing research avenues. We find that the landscape of public avian influenza research is not directly driven by expectations of societal outcomes. Instead, it is shaped by three institutional drivers: pharmaceutical industry priorities, publishing and public research funding pressures, and the mandates of science-based policy or public health organizations. These insights suggest that, in research prioritization, funding agencies should embrace a broad perspective of research governance that explicitly considers underlying institutional drivers. Deliberative approaches in public priority setting might help to make agendas more plural and diverse and thus more responsive to the contested and uncertain nature of avian influenza research.  相似文献