Research On Organization Method For The Railway Express Freight Transportation Based On Rationalizing Transport Structure

There are various transportation modes in transportation system.Only by giving full utilization to the comparative advantages of various transportation modes,the logistics cost can be reduced and the transportation efficiency can be maximized.One of the evaluation indexes is the share ratio of each transportation mode in transporting passengers and freights,which can evaluate whether the transportation structure is reasonable.In China,the proportion of freight volume completed by the road is 74% at present,which is 7.83 times of the total amount completed by the railway.It is obvious that the transportation structure is unreasonable.In addition,timeliness has become the main index in evaluating shipper's satisfaction according to a large number of investigation.Therefore,the effective measures to improve the railway proportion in express freight transportation are determined as the research theme of this paper.And new express freight products are provided from a practical point of view.Pallet,as one of the most commonly used transport carriers in domestic and foreign express freight transportation,has been rapidly developed and widely used.The concepts of‘logistics palletization' and ‘palletized containerization unit' have been put forward in logistics field.Combined with the practical utilization of pallets in the railway freight yards,a new type of pallet which size can be stretched is designed based on the standard pallet of1100×1100mm.Take the three common materials as the example,the paper carries out their finite element analysis of static and dynamic loading by Solid Works.The allowable loading volume of pallets after stretching different lengths are validated,and the size matching of pallets before and after stretching are also compared according to the some common used kinds of railway vehicles.It can make up for the shortage that the size-defined standard pallet can not meet the needs in containerizing various packed goods,provide a effective containerization equipment for packages and realize their mechanical loading and unloading in express transportation.In view of the features of large loading capacity and complex organization,the railway express freight transportation problem should be studied in two aspects: insufficient freight volume and sufficient freight volume.Considering the fact that the capacity of the luggage cars of passenger trains is underutilized,a new transport means,the Multi Package and Multi Train Pick-up and Delivery with Time Window(MPMT-PDTW),is proposed in this paper.It aims to deliver packages as quickly as possible with the minimum cost,and maximize the re-utilization of the redundant capacity of luggage cars at the same time.On the premise that packages have been containerized by pallets or other containerization equipment,the operation efficiency of forks should be considered.The Quality of Service(Qo S)is defined as the evaluation standard of package express transportation by luggage cars under the multiple constraints of limited carrying capacity and fixed duration time.The characteristics of this express transportation means are that it does not need to consider the minimization of transportation cost,and the loading and unloading operations would not affect the normal operation of passenger trains.The example shows that the Greedy Randomized Adaptive Search Procedure(GRASP)designed for this problem can provide a feasible solution for the packages assignment at each passenger transport station.After years of development,the railway express transportation has formed its own feature.However,the container express means can not satisfy the transportation demand.There isn't an efficient way for containers' collection and distribution in inland areas,and the railway proportion is too low.Therefore,this paper proposes a new express mode by operating freight train for containers' collection and distribution according to the operation mode of the passenger train.In view of the current ‘one map per day' operation mode of passenger train,it is necessary to forecast the freight volume in 3-5 days.Considering the volatility and complexity of the time series of railway freight volume,a new comprehensive decomposition ensemble forecasting approach,VMD-FK-FK,is proposed.In order to reduce the complexity of the actual data,the Variational Mode Decomposition(VMD)is used as the data pre-processing module to decompose the observed data into several modal branches.The Kernel Extremum Learning Mechanism(KELM)of Fruit Fly(FK)optimization algorithm is used to build the prediction module to predict each modal branch.Based on another FK optimization algorithm,an integrated strategy is established to integrate the prediction results of each modal branch and to get the final prediction results.Experimental results demonstrate that the proposed decomposition ensemble approach in this paper can achieve the best prediction performance under different evaluation criteria compared with other benchmark models.The accurate freight volume prediction is the basic for the railway to operate the train according to the operation mode of passenger train for containers' collection and distribution.Because data collection at ports is different from that of the railway,a lot of basic data are scattered among the shipping companies and their agents.In order to obtain the detailed collection and distribution contain volume,firstly the K-means clustering method is used to deal with the container throughput in different months and years.Secondly geographic divisions within the radiation range of 400 km from different ports is completed by Arc GIS.Thirdly take Shanghai port as an example,the proportion of GDP is applied to determine the container collection and distribution stations within the radiation range.So the clustering data can be allocated to each collection and distribution station,which provide the basic data for prediction by VMD-FK-FK.Furthermore the multi-objective programming model is established,and the improved NSGA-? is designed so as to achieve the goal of the shortest delivery time and the maximum transportation revenue.MATLAB is adopted to obtain the non-dominated feasible solution set of the train operation scheme based on the predicted data of the Shanghai port.The results show that the operation of the train can not only effectively alleviate congestion at ports,but also obtain considerable transportation revenue for the railway.More importantly,the transportation structure in container collecting and distributing at ports will tend to be reasonable.