As a new variant of vehicle routing problem( VRP),a finished vehicle routing problem with time windows in finished vehicle logistics( FVRPTW) is modeled and solved. An optimization model for FVRPTW is presented with t...As a new variant of vehicle routing problem( VRP),a finished vehicle routing problem with time windows in finished vehicle logistics( FVRPTW) is modeled and solved. An optimization model for FVRPTW is presented with the objective of scheduling multiple transport routes considering loading constraints along with time penalty function to minimize the total cost. Then a genetic algorithm( GA) is developed. The specific encoding and genetic operators for FVRPTW are devised.Especially,in order to accelerate its convergence,an improved termination condition is given. Finally,a case study is used to evaluate the effectiveness of the proposed algorithm and a series of experiments are conducted over a set of finished vehicle routing problems. The results demonstrate that the proposed approach has superior performance and satisfies users in practice. Contributions of the study are the modeling and solving of a complex FVRPTW in logistics industry.展开更多
'When the oil price grows by 100%, the logistic industry will see a price growth of 40%,while the logistics industry a price rise of 35%,which means every price increase of 5%in the oil price will bring along that...'When the oil price grows by 100%, the logistic industry will see a price growth of 40%,while the logistics industry a price rise of 35%,which means every price increase of 5%in the oil price will bring along that of 2%in this industry.' said Liu Zongsheng,General Manager of Itochu Logistics Co.,Ltd., on the seminar 'Focusing on the economic consequences of raising oil price, interest rate and deposit reserve ratio', which was held recently. What he said is on the mind of all others in this industry.With the oil price rising continually,the originally severely competitive industry is suffering from the costs growth.展开更多
Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high...Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high-performance rotational energy harvesting.A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes(DEMs).Moreover,a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion,which can be further converted into electricity through the DEMs.First,the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system.Second,the prototype is fabricated,and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated.The experimental results show that adequate charging time and discharging time of the DEMs,which can be realized through the proposed cam-like mechanisms,are beneficial to the energy harvesting(EH)performance of the system.Third,with the validated theoretical model,numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement.Finally,the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG,demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.展开更多
基金Supported by the National Natural Science Foundation of China(No.51565036)
文摘As a new variant of vehicle routing problem( VRP),a finished vehicle routing problem with time windows in finished vehicle logistics( FVRPTW) is modeled and solved. An optimization model for FVRPTW is presented with the objective of scheduling multiple transport routes considering loading constraints along with time penalty function to minimize the total cost. Then a genetic algorithm( GA) is developed. The specific encoding and genetic operators for FVRPTW are devised.Especially,in order to accelerate its convergence,an improved termination condition is given. Finally,a case study is used to evaluate the effectiveness of the proposed algorithm and a series of experiments are conducted over a set of finished vehicle routing problems. The results demonstrate that the proposed approach has superior performance and satisfies users in practice. Contributions of the study are the modeling and solving of a complex FVRPTW in logistics industry.
文摘'When the oil price grows by 100%, the logistic industry will see a price growth of 40%,while the logistics industry a price rise of 35%,which means every price increase of 5%in the oil price will bring along that of 2%in this industry.' said Liu Zongsheng,General Manager of Itochu Logistics Co.,Ltd., on the seminar 'Focusing on the economic consequences of raising oil price, interest rate and deposit reserve ratio', which was held recently. What he said is on the mind of all others in this industry.With the oil price rising continually,the originally severely competitive industry is suffering from the costs growth.
基金supported by the National Natural Science Foundation of China(Grant Nos.52205114,51905349,U2013603)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022A1515010126,2023A1515012921,2020A1515011509)+1 种基金Excellent Science and Technology Creative Talent Training Program of Shenzhen,China(Grant No.RCBS20221008093252089)Shenzhen Natural Science Fund(the Stable Support Plan Program 20220809181431001)。
文摘Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high-performance rotational energy harvesting.A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes(DEMs).Moreover,a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion,which can be further converted into electricity through the DEMs.First,the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system.Second,the prototype is fabricated,and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated.The experimental results show that adequate charging time and discharging time of the DEMs,which can be realized through the proposed cam-like mechanisms,are beneficial to the energy harvesting(EH)performance of the system.Third,with the validated theoretical model,numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement.Finally,the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG,demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.
