For the optimization problem of the cold-chain emergency materials(CEM) distribution routes with multi-demand centers and soft time windows and to solve dispatching materials to medical treatment institutions in vario...For the optimization problem of the cold-chain emergency materials(CEM) distribution routes with multi-demand centers and soft time windows and to solve dispatching materials to medical treatment institutions in various places of the disaster areas under COVID-19, a multi-dimensional robust optimization(MRO) model was proposed, which was solved by a hybrid algorithm combined Pareto genetic algorithm and the improved grey relative analysis(IGRA). The proposed model comprehensively takes into consideration of the cost factors of the cold-chain logistics and robustness of solution with the purpose of minimizing the costs and maximizing robustness. The availability of the proposed approach and hybrid algorithm were thoroughly discussed and qualified through a real-world numerical simulation test case, which was a previous risk area located at Hubei Province. Research results show an average-cost reduction of 4.51% and a robustness increment of 11.69% in addition to consider the urgencies of demand. Consequently, not only the costs can be slightly reduced and the robustness be heightened, but also the blindness of the distribution can be avoided effectively with the demand urgency being considered. Research result indicates that when combining with the specific process of supplies dispatching in the prevention and control, the proposed approach is in a far better agreement in practice, and it could meet the diverse requirements of the emergency scenarios flexibly.展开更多
Herbicides with drip irrigation(chemigation)could control the herbicides application accurately as the irrigation technology,and could reduce the harm to humans and the environment.However,the herbicide concentration ...Herbicides with drip irrigation(chemigation)could control the herbicides application accurately as the irrigation technology,and could reduce the harm to humans and the environment.However,the herbicide concentration is not consistent in the advancing process along the drip irrigation tape of different lengths,which not only influences the crop growth and results in herbicide residue.In this study,the crop and environmental effects of chemigation were discussed,potassium permanganate was used to replace herbicides,and a laboratory test was conducted to determine the best application duration.Based on this result,the maize field experiment of chemigation under plastic mulch was carried out to compare the effects of maize growth index,yield and herbicide residue for determining the optimal chemigation mode.The result shows that there is no significant difference in the application uniformity among treatments,but the leaf area index(LAI),yield,and double-ear rate of maize under continuous application(CA)were higher than those under periodic application(PA)and no application(NA)significantly.One month after the application,the acetochlor residue of the two modes was less than 1%,which would not cause pollution to the surrounding environment.And there was a significant linear regression relationship between the length of drip irrigation tape and the optimal application duration under the same acetochlor dosage.展开更多
基金supported by the National Natural Science Foundation of China (No.52062027,71861023 and 52002282)the "Double-first Class" Major Research Programs,Educational Department of Gansu Province (No.GSSYLXM-04)+1 种基金supported by the Natural Science Foundation of Zhejiang Province (LY21E080010)Philosophy and Social Science Foundation of Zhejiang Province (No.21NDJC163YB,22NDJC166YB)。
文摘For the optimization problem of the cold-chain emergency materials(CEM) distribution routes with multi-demand centers and soft time windows and to solve dispatching materials to medical treatment institutions in various places of the disaster areas under COVID-19, a multi-dimensional robust optimization(MRO) model was proposed, which was solved by a hybrid algorithm combined Pareto genetic algorithm and the improved grey relative analysis(IGRA). The proposed model comprehensively takes into consideration of the cost factors of the cold-chain logistics and robustness of solution with the purpose of minimizing the costs and maximizing robustness. The availability of the proposed approach and hybrid algorithm were thoroughly discussed and qualified through a real-world numerical simulation test case, which was a previous risk area located at Hubei Province. Research results show an average-cost reduction of 4.51% and a robustness increment of 11.69% in addition to consider the urgencies of demand. Consequently, not only the costs can be slightly reduced and the robustness be heightened, but also the blindness of the distribution can be avoided effectively with the demand urgency being considered. Research result indicates that when combining with the specific process of supplies dispatching in the prevention and control, the proposed approach is in a far better agreement in practice, and it could meet the diverse requirements of the emergency scenarios flexibly.
基金support from the National Natural Science Foundation of China(Grant No.U2243235,52079113).
文摘Herbicides with drip irrigation(chemigation)could control the herbicides application accurately as the irrigation technology,and could reduce the harm to humans and the environment.However,the herbicide concentration is not consistent in the advancing process along the drip irrigation tape of different lengths,which not only influences the crop growth and results in herbicide residue.In this study,the crop and environmental effects of chemigation were discussed,potassium permanganate was used to replace herbicides,and a laboratory test was conducted to determine the best application duration.Based on this result,the maize field experiment of chemigation under plastic mulch was carried out to compare the effects of maize growth index,yield and herbicide residue for determining the optimal chemigation mode.The result shows that there is no significant difference in the application uniformity among treatments,but the leaf area index(LAI),yield,and double-ear rate of maize under continuous application(CA)were higher than those under periodic application(PA)and no application(NA)significantly.One month after the application,the acetochlor residue of the two modes was less than 1%,which would not cause pollution to the surrounding environment.And there was a significant linear regression relationship between the length of drip irrigation tape and the optimal application duration under the same acetochlor dosage.
