不同决策模式下农产品质量控制策略研究

农产品质量已经引起公众的广泛关注。考虑由一个供应商和一个零售商构成的两级农产品供应链,构建零售商主导下的Stackelberg分散决策博弈模型和两者协同合作下的集中决策博弈模型,以供应商和零售商的最优质量努力水平为状态变量,利用逆向求解法得出供应商和零售商的最优质量决策。研究表明:在一定条件下,农产品供应链中主体的合作可以实现供应商、零售商和整个供应链系统利润的Pareto改善,在此基础上分析实现Pareto改善的条件以推动农产品供应链达到协调。     

冲突视角下运输订单商业竞争战略研究

运用图模型理论研究冲突视角下中欧班列运营过程中运输订单商业竞争战略,构建“渝新欧”班列运营商、“苏满欧”班列运营商和昆山IT企业之间的商业竞争冲突模型。利用TOPSIS法评估班列的运输效率,确定决策者偏好,通过计算均衡解获得符合各决策者利益的理性对策。借助灵敏度分析研究决策者偏好改变对模型冲突结果的影响。研究表明:在竞争中,运输效率较低的一方可以通过降低价格弥补自身劣势而获得订单;运输效率较高的一方只有通过降价才能获得订单。该研究为班列运营商提供利益冲突中的商业竞争战略,能为顾客企业选择高效合理的运输线路提供有效的战略决策,同时亦能为宏观调控者规范市场、提高市场运输效率提供有效的政策启示。     

农民工养老保险参与决策：一个OLG模型的考察

通过构建一个农民工追求跨期效用最大化的OLG模型,理论分析了均衡条件下农民工收入及风险偏好因素对其养老保险参与决策的影响;基于全国31个省市的调查数据,利用双变量Probit模型实证分析了个人与家庭特征、收入与土地、务工状况与预期等因素对农民工养老保险参与决策的影响。结果表明：务工与务农收入对农民工参与养老保险决策的影响并不显著,而恩格尔系数和非收入性因素却大多显著地影响了农民工的参保决策。为此,一方面,要提高农民工的收入水平、生活宽裕程度和支付能力,使之更有意愿和能力参与养老保险;另一方面,要增强农民工对未来生活确定性的预期和安全感,使之参与养老保险的水平得以提高。     

Tolerance of Uncertainty: Links to Happenstance,Career Decision Self‐Efficacy,and Career Satisfaction

This study investigated the extent to which tolerance of uncertainty affects the relationship between happenstance skills and career satisfaction via career decision self‐efficacy. Moderated mediation analysis was conducted on data collected from 321 graduates (175 men, 146 women) of Korean universities making the school‐to‐work transition. Results showed that career decision self‐efficacy fully mediated the relationship between happenstance skills and career satisfaction. Furthermore, the moderation effect of tolerance of uncertainty had a significant impact on the relationship between happenstance skills and career decision self‐efficacy. Tolerance of uncertainty should be considered an important variable in happenstance career theory and intervention. Unplanned influences should also be considered important factors in the career decision‐making process.     

Persuasion: An experimental study of team decision making

This paper studies persuasion within teams and investigates why teams commonly take, by some measures, better decisions than individuals. The analysis is based on data from electronic communication within teams of two players. Thanks to the experimental design, changes of an individual’s decision can be attributed to the content of the team partner’s message. The results for knowledge-related and strategic problems show that individuals’ decisions change upon receiving more informative and sophisticated arguments and remain the same otherwise. This individual behavior is an essential part of the information aggregation in teams and can explain the advantage of teams in decision making and in games.     

考虑零件三维装载约束带时间窗的循环取货路径问题研究

为提高车辆的可装载性,对考虑三维装载约束带时间窗的循环取货路径问题进行研究.在给定假设与约束条件的前提下,建立该问题的多目标数学模型,并设计用于问题求解的基于改进策略的启发式算法.数值实例的计算结果表明,该算法可有效求解考虑零件三维装载约束带时间窗的循环取货路径问题;且与时间窗优先法的求解结果相比,可大幅提高车辆的可装载性,并能有效减少不同车型车辆的投入数量.     

Children in immediate danger: Emergency removals in Finnish and Irish child protection

This paper presents a qualitative analysis of front‐line practices regarding emergency removals in Finnish and Irish child protection. It examines how the responses to children's immediate danger are framed by legislation and how front‐line practitioners assess the child's situation and make emergency placement decisions. The data consist of interviews with 16 Irish and 33 Finnish social workers. These child welfare protection systems respond differently to a task that appears to be similar. The Irish team‐based practice rests on the social workers' shared assessment of the child's needs, and the formal decision is made by the courts (or police officers at night‐time); and the Finnish practice involves only one single social worker who makes both the assessment and the removal decision. The Irish system is tightly time regulated, whereas the Finnish system provides a more flexible time frame. Both approaches put a lot of stress on social workers' practice, which also includes creative workarounds (e.g., “planned emergency removals” in Finland). Future research will need to explore these features from the point of view of a child's right to protection.     

Asymptotic Theory of Outlier Detection Algorithms for Linear Time Series Regression Models

Outlier detection algorithms are intimately connected with robust statistics that down‐weight some observations to zero. We define a number of outlier detection algorithms related to the Huber‐skip and least trimmed squares estimators, including the one‐step Huber‐skip estimator and the forward search. Next, we review a recently developed asymptotic theory of these. Finally, we analyse the gauge, the fraction of wrongly detected outliers, for a number of outlier detection algorithms and establish an asymptotic normal and a Poisson theory for the gauge.     

Perceptions of Randomized Security Schedules

Security of infrastructure is a major concern. Traditional security schedules are unable to provide omnipresent coverage; consequently, adversaries can exploit predictable vulnerabilities to their advantage. Randomized security schedules, which randomly deploy security measures, overcome these limitations, but public perceptions of such schedules have not been examined. In this experiment, participants were asked to make a choice between attending a venue that employed a traditional (i.e., search everyone) or a random (i.e., a probability of being searched) security schedule. The absolute probability of detecting contraband was manipulated (i.e., 1/10, 1/4, 1/2) but equivalent between the two schedule types. In general, participants were indifferent to either security schedule, regardless of the probability of detection. The randomized schedule was deemed more convenient, but the traditional schedule was considered fairer and safer. There were no differences between traditional and random schedule in terms of perceived effectiveness or deterrence. Policy implications for the implementation and utilization of randomized schedules are discussed.     

Self‐Construal,Career Decision Self‐Efficacy,and Perceived Barriers Predict Mexican American Women's Life Satisfaction

This study used the social cognitive theory of well‐being (SCTW; Lent, 2004 ) to examine the role of career decision self‐efficacy (CDSE), perceived educational barriers, and independent self‐construal on the life satisfaction of 176 Mexican American college women. A 3‐step hierarchical regression analysis indicated that independent self‐construal, CDSE, and fewer perceived educational barriers significantly predicted greater life satisfaction among Mexican American college women above and beyond the influence of socioeconomic status and generational status. These findings are consistent with SCTW and highlight the need for counselors and researchers to be aware of the role that self‐construal, CDSE, and perceived educational barriers can have on Mexican American women's life satisfaction. Implications for practice at the secondary‐school and university levels are discussed.