As the status of order picking in the warehousing and distribution system has been raised,the work-rest scheduling of picking becomes particularly important.Although science and technology have developed rapidly,manua...As the status of order picking in the warehousing and distribution system has been raised,the work-rest scheduling of picking becomes particularly important.Although science and technology have developed rapidly,manual picking is still essential and indispensable.However,previous researches focused on the study of the sequencing,ignoring human factors.The paper presents a work-rest schedule model in parts to picker picking system.Two objectives are proposed that include minimizing the picking time and minimizing picking error rate.And workers'fatigue,workload is taken into account in the manual order picking systems because the fatigue can have a large influence on the picking time and the picking error rate.A genetic algorithm is used to solve a multi-objective optimization problem that the model concerns and looking for a Pareto front as the most effective methods for solving this problem.Once the original data is given,the work-rest scheduling model is built and the work sequence,and the number of breaks are determined to be chosen by decision makers.In addition,a case study of the model is used to confirm that the model is effective and it is necessary to consider the human factor in the picking system.展开更多
A version of an electric vehicle was developed and designed for the US market on the basis of the required domestic body structure.When compared with the original car,the new car body design leads to two major technic...A version of an electric vehicle was developed and designed for the US market on the basis of the required domestic body structure.When compared with the original car,the new car body design leads to two major technical difficulties.First,the installation of high-voltage components such as the battery pack and other new energy sources increases the vehicle weight and occupies a great deal of its structural space;this limits the impact paths and the use of traditional structural designs,which greatly increases the design difficulty.Second,the USA,as an advanced automobile-using country,has well-developed laws and regulations for collision standards,vehicle operating conditions and evaluation standards.Using a combination of butterfly diagram analysis,bending moment management,section forces and other computer-aided simulation and analysis techniques,this paper presents a body structure design that can achieve a“GOOD”evaluation under the US Insurance Institute for Highway Safety(IIHS)side impact body structure conditions by optimizing the force transfer path,the B-pillar deformation mode and the threshold support structure.The threshold support structure supports realization of the“GOOD”rating for IIHS side impact and helps the body to meet the crash requirements of the Federal Motor Vehicle Safety Standard FMVSS214 and the US New Car Assessment Program(NCAP)requirements for side impact at 32 km/h and 75°angular pole impact.展开更多
文摘As the status of order picking in the warehousing and distribution system has been raised,the work-rest scheduling of picking becomes particularly important.Although science and technology have developed rapidly,manual picking is still essential and indispensable.However,previous researches focused on the study of the sequencing,ignoring human factors.The paper presents a work-rest schedule model in parts to picker picking system.Two objectives are proposed that include minimizing the picking time and minimizing picking error rate.And workers'fatigue,workload is taken into account in the manual order picking systems because the fatigue can have a large influence on the picking time and the picking error rate.A genetic algorithm is used to solve a multi-objective optimization problem that the model concerns and looking for a Pareto front as the most effective methods for solving this problem.Once the original data is given,the work-rest scheduling model is built and the work sequence,and the number of breaks are determined to be chosen by decision makers.In addition,a case study of the model is used to confirm that the model is effective and it is necessary to consider the human factor in the picking system.
文摘A version of an electric vehicle was developed and designed for the US market on the basis of the required domestic body structure.When compared with the original car,the new car body design leads to two major technical difficulties.First,the installation of high-voltage components such as the battery pack and other new energy sources increases the vehicle weight and occupies a great deal of its structural space;this limits the impact paths and the use of traditional structural designs,which greatly increases the design difficulty.Second,the USA,as an advanced automobile-using country,has well-developed laws and regulations for collision standards,vehicle operating conditions and evaluation standards.Using a combination of butterfly diagram analysis,bending moment management,section forces and other computer-aided simulation and analysis techniques,this paper presents a body structure design that can achieve a“GOOD”evaluation under the US Insurance Institute for Highway Safety(IIHS)side impact body structure conditions by optimizing the force transfer path,the B-pillar deformation mode and the threshold support structure.The threshold support structure supports realization of the“GOOD”rating for IIHS side impact and helps the body to meet the crash requirements of the Federal Motor Vehicle Safety Standard FMVSS214 and the US New Car Assessment Program(NCAP)requirements for side impact at 32 km/h and 75°angular pole impact.
