The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding...The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding comparative optimal solutions under decentralized decision. In the supply coordination, the collaboration between suppliers in assembly system is usually not considered. As a result, the manufacturer’s production is often delayed due to mismatching delivery of components between suppliers. Therefore, to ensure supply coordination in assembly system, collaboration between suppliers should be taken into consideration. In this paper, an assembly system with two suppliers and one manufacturer under uncertain delivery time is considered. The model is established and optimal solution is given under decentralized decision. Furthermore, the cost functions of two suppliers are both convex, and a unique Nash equilibrium exists between two suppliers. Then the optimal decision under supply coordination is analyzed, which is regarded as a benchmark for supply coordination. Additionally, the total cost of the assembly system is jointly convex in agreed delivery time. To achieve supply coordination a bonus policy is explored in the assembly system under uncertain delivery time, and the total cost under bonus policy must be lower than under decentralized decision. Finally the numerical and sensitivity analysis shows the cost of assembly system under bonus policy equals that under supply coordination, and the cost of each side in assembly system under bonus policy is lower compared to that under decentralized decision. The proposed research minimizes the total cost of each side with bonus policy in assembly system, ensures the supply coordination between suppliers and the manufacturer, and improves the competiveness of the whole supply chain.展开更多
Gaokao has been considered as the gatekeeper of intergenerational class reproduction in today’s slowing social mobility in China.In order to bolster the fairness of Gaokao,the Policy of Bonus Scores for Ethnic Minori...Gaokao has been considered as the gatekeeper of intergenerational class reproduction in today’s slowing social mobility in China.In order to bolster the fairness of Gaokao,the Policy of Bonus Scores for Ethnic Minority Candidates(PBSEMC)has been issued,whose,however,effectiveness in promoting upward social class has not been adequately empirically explored.The difference-in-differences(DID)analysis based on cross-sectional data,which is distinct from the traditional DID analysis paradigm,was implemented to assess the Reform of PBSEMC in the Guangxi Zhuang Autonomous Region in 1988.The results showed that PBSEMC had a significant and positive impact on the social classes of ethnic minorities,and gender,residence type and occupation type were also relevant to social class,aligning with the previous literature.The PBSEMC is effective in improving the social classes of ethnic minorities.However,the PBSEMC policy should be made more precise,in order to benefit the candidates who are in genuine need of assistance.展开更多
基金supported by National Natural Science Foundation of China(Grant No. 71102174)Beijing Municipal Natural Science Foundation of China(Grant Nos. 9123028, 9102016)+3 种基金Specialized Research Fund for Doctoral Program of Higher Education of China(Grant No. 20111101120019)Beijing Municipal Philosophy and Social Science Foundation of China(Grant No. 11JGC106)Program for New Century Excellent Talents in University of China(Grant Nos. NCET-10-0048,NCET-10-0043)Excellent Young Teacher in Beijing Institute of Technology of China(Grant No. 2010YC1307)
文摘The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding comparative optimal solutions under decentralized decision. In the supply coordination, the collaboration between suppliers in assembly system is usually not considered. As a result, the manufacturer’s production is often delayed due to mismatching delivery of components between suppliers. Therefore, to ensure supply coordination in assembly system, collaboration between suppliers should be taken into consideration. In this paper, an assembly system with two suppliers and one manufacturer under uncertain delivery time is considered. The model is established and optimal solution is given under decentralized decision. Furthermore, the cost functions of two suppliers are both convex, and a unique Nash equilibrium exists between two suppliers. Then the optimal decision under supply coordination is analyzed, which is regarded as a benchmark for supply coordination. Additionally, the total cost of the assembly system is jointly convex in agreed delivery time. To achieve supply coordination a bonus policy is explored in the assembly system under uncertain delivery time, and the total cost under bonus policy must be lower than under decentralized decision. Finally the numerical and sensitivity analysis shows the cost of assembly system under bonus policy equals that under supply coordination, and the cost of each side in assembly system under bonus policy is lower compared to that under decentralized decision. The proposed research minimizes the total cost of each side with bonus policy in assembly system, ensures the supply coordination between suppliers and the manufacturer, and improves the competiveness of the whole supply chain.
基金supported by National Social Science Foundation(21BZZ021).
文摘Gaokao has been considered as the gatekeeper of intergenerational class reproduction in today’s slowing social mobility in China.In order to bolster the fairness of Gaokao,the Policy of Bonus Scores for Ethnic Minority Candidates(PBSEMC)has been issued,whose,however,effectiveness in promoting upward social class has not been adequately empirically explored.The difference-in-differences(DID)analysis based on cross-sectional data,which is distinct from the traditional DID analysis paradigm,was implemented to assess the Reform of PBSEMC in the Guangxi Zhuang Autonomous Region in 1988.The results showed that PBSEMC had a significant and positive impact on the social classes of ethnic minorities,and gender,residence type and occupation type were also relevant to social class,aligning with the previous literature.The PBSEMC is effective in improving the social classes of ethnic minorities.However,the PBSEMC policy should be made more precise,in order to benefit the candidates who are in genuine need of assistance.