Issue 04, 2026
Research on the Quality Evaluation of Air-Rail Intermodal Transportation Based on SEM-Cloud Model
LI Chenxu;CHEN Xue;As a core practice of the Mobility as a Service(MaaS) concept,air-rail intermodal transport is a key mode for achieving seamless intermodal connectivity for passengers. The scientific nature of the passenger satisfaction evaluation index system for air-rail intermodal transport is verified through a structural equation model,and the weights of each index are determined. The cloud model is used to comprehensively evaluate the service quality of air-rail intermodal transport,and the importance-performance analysis(IPA) method is adopted to quantify the importance of service and passenger satisfaction. The results show that the overall service quality of air-rail intermodal transport under different transfer modes is at a medium to high level. Among them,in the physical connection transfer mode,the influence degree of the four latent variables from high to low is transfer service,personalized service,reliability service,and ticket service. In the indirect connection transfer mode,the influence degree of the four latent variables is transfer service,reliability service,personalized service,and ticket service. In addition,the IPA analysis results further verify that there are significant differences in the key indicators affecting passenger service quality under different transfer modes.
Optimization Model of Stop Schemes for Cross-Border Trains Considering Delay Risk of High-Added-Value Goods
DUAN Liwei;CHEN Ying;In response to the problems of long waiting times and insufficient coverage of small-batch,high-value goods along the cross-border train routes during regular transportation organization,which have led to high detention rates and poor timeliness,a "selective stopping" cross-border train transportation organization model is explored and proposed. This model incorporates the risk cost of goods delay into the optimization system of cross-border train stop schemes,with train capacity,goods demand,and stop time as constraints,and aims to minimize the enterprise operation cost and the risk cost of goods delay,thereby establishing a multi-objective optimization model. The model is solved using the fast non-dominated sorting genetic algorithm(NSGA-Ⅱ) with an elite strategy. A simulation analysis is conducted using a certain cross-border train channel as an example,and the Pareto optimal solution set is ultimately obtained. The results show that the top solution has the lowest total cost,reducing it by 38.43% compared to the bottom solution; while the bottom solution can reduce the risk cost of delay by 26.25% and serve 3.65% more container goods along the route,providing decision-makers with multiple reasonable stop schemes.
Planning of Electric Bus Charging Station Location and Capacity Considering Opportunity Charging and Battery Capacity Degradation
WANG Yu;YU Kuo;ZHANG Ran;GE Feng;With the wide application of electric buses,the location selection and capacity determination of charging stations have significantly affected the charging efficiency of electric buses and the costs of bus companies. The layout of charging stations and the capacity configuration for electric buses are of great significance in improving the operational efficiency of public transportation,reducing charging costs,and alleviating the pressure on the power grid. To address these issues,a charging station location algorithm and a capacity configuration planning model have been developed. Firstly,the dynamic adjustment progressive coverage function was introduced into the affinity propagation clustering algorithm,making the determination of centralized charging stations and their served bus stops more flexible. Secondly,the opportunity charging strategy and the battery capacity attenuation model were innovatively incorporated into the capacity configuration planning model,establishing an optimization model with the objective of minimizing the fixed costs of the bus company,the charging costs including opportunity charging,and the operational battery degradation cost including battery penalty costs. The CBC solver was used to solve the model. Finally,taking a part of the bus network in Shenyang as an example,the layout of charging stations and the number of charging piles at each station were determined. The reliability of the model was verified through sensitivity tests under different charging powers and environmental temperatures. The results show that by using the opportunity charging strategy and the battery capacity attenuation model,the comprehensive cost can be significantly reduced to 113 million yuan,and the battery life can be increased by 4.5%,providing a theoretical basis and practical reference for the construction of urban electric bus charging networks.
Simulation of Dynamic Evacuation in Underground Commercial Street Fires Based on the Coupled FDS+CA Model
SHI Jianyun;WANG Ying;REN Yihua;To study the evacuation patterns of people in fire scenarios,a fire evacuation model based on FDS+CA was established. Firstly,FDS was used to conduct numerical simulations of fires,and the real-time data of fire dynamics were loaded into the CA model to continuously reflect the impact of the fire environment on the evacuation behavior of people. Secondly,a simulation was conducted with an underground commercial street as the research object,and the fire spread and evacuation results under different scenarios were analyzed in combination with Monte Carlo simulation. The research shows that the location of the fire source is a key factor affecting the evacuation efficiency of people. When the fire source is close to the evacuation exit,the risk of local evacuation failure increases significantly,and the number of trapped in the area increases significantly. The heat release and smoke diffusion of the fire source can cause the failure of surrounding evacuation paths,and some exits cannot meet the evacuation conditions,thereby prolonging the overall evacuation time. Due to the influence of spatial layout,the speed of smoke diffusion varies significantly,and the smoke spreads particularly rapidly in areas with low obstacles. In a closed underground space,a mechanical smoke exhaust system can effectively reduce the smoke concentration and improve the evacuation efficiency. The research results can provide references for the evacuation and fire protection design of underground commercial streets in fire scenarios.
A Study on Prediction of High-Risk Points for Mountainous Road Accidents Based on Improved Kernel Density Estimation
CHENG Rui;BI Yunjian;PAN Ye;WANG Tao;Mountainous road conditions are poor and driving environments are complex,leading to frequent traffic accidents with severe casualties. To enhance the safety level of driving on mountainous roads,this study comprehensively assesses high-risk sections of traffic accidents based on the traffic accident data of mountainous roads in Guilin City from 2019 to 2023,using a kernel density estimation method that considers the severity of accidents. Firstly,the accident samples are divided into high-risk and low-risk groups based on the identification results of risk sections. Secondly,chi-square analysis is used to explore the key influencing factors of accident risk,and a Bayesian network is employed to construct a prediction model for high-risk points of traffic accidents on mountainous roads. The results show that road type,intersection and section type,and central isolation facilities have a significant impact on the severity of accidents,among which road type and central isolation facilities directly affect the probability of accident risk. The constructed prediction model can assess the probability of accident risk under different accident forms and severity levels. The research results can provide a decision-making basis for formulating differentiated accident prevention policies for mountainous roads.
Traffic Accident Severity Prediction Method Based on Data-Algorithm Collaborative Optimization
HUANG Yishao;ZHOU Runxiang;Traffic accident prediction is of great significance for improving the level of road traffic safety management. However,existing prediction methods generally have problems such as imbalanced data categories and low model hyperparameter optimization,which lead to insufficient prediction accuracy of the model. Therefore,an optimized random forest model integrating an adaptive hybrid sampling algorithm and an improved Bayesian algorithm is proposed for traffic accident severity prediction. Firstly,to address the issue of imbalanced distribution of traffic accident data,an adaptive weight calculation method is introduced on the basis of the traditional SMOTE-ENN algorithm. By dynamically adjusting the SMOTE oversampling rate and ENN undersampling threshold,targeted generation of minority class samples and elimination of majority class samples are achieved,effectively enhancing the classifier's sensitivity to accident features. Secondly,to enhance the model's generalization ability,the anisotropic Matern 5/2 kernel function is adopted to replace the traditional Gaussian kernel function,and a dynamic exploration factor is introduced to improve the efficiency of optimizing algorithm hyperparameters. Finally,the random forest model is used to complete the modeling of traffic accident severity prediction. The research results show that the K value of the proposed model after consistency test is 0.913 1,indicating that the model has high prediction consistency; the recall rate reaches 84.23%,achieving a significant improvement in traffic accident prediction evaluation compared to other classification models. This method can greatly improve the prediction accuracy of minority category accidents and significantly improve the model's generalization performance. Compared with the traditional SMOTE-ENN algorithm,the adaptive SMOTE-ENN algorithm improves the accuracy,recall rate,precision,and F1 value by 2.06,1.17,4.03,and 2.51 percentage points respectively,and has better comprehensive performance than other sampling algorithms. Compared with other optimization algorithms,the improved Bayesian optimization algorithm has better prediction performance and feasibility. The research conclusion confirms that this method can provide theoretical reference for traffic safety research.
Rolling Bearing Remaining Life Prediction Based on Multi-Source Data Fusion
LI Yonghua;YIN Xuejiao;CHEN Zhe;HU Chaoqun;CAO Jiahong;Most of the existing methods for constructing bearing health indicators rely solely on vibration monitoring data to obtain performance degradation variables,which makes it difficult to comprehensively reflect the actual health status of the bearing and thus affects the accuracy of remaining useful life prediction. To address this issue,a bearing remaining useful life prediction method based on multi-source data fusion is proposed. Firstly,the Moth-Flame Optimization algorithm is used to determine the optimal hyperparameters of the variational mode decomposition,decomposing the data into a predetermined number of subsequences within a specific interval,fully exploring the hidden time series features in multi-dimensional data,and fusing the vibration and temperature signal features of the bearing to construct a composite health indicator. Secondly,a random model is used to describe the degradation evolution process of the bearing health indicator,and the initial parameters of the model are estimated and solved by maximizing the log-likelihood function. Finally,the Bayesian formula is used to update the model parameters in real time,obtaining the probability distribution result of the bearing's remaining useful life. Simulation verification is carried out based on the bearing full life test data set. The results show that the proposed health indicator can accurately reflect the health status of the bearing and effectively improve the accuracy of bearing remaining useful life prediction.
Study on Fatigue Characteristics of Composite Hydraulic-Rubber Swing Arm Node for Railway Vehicles
LUO Jun;LIU Wensong;CHEN Junhui;ZUO Binhuai;LI Jing;TANG Yunlun;HOU Maorui;To achieve both excellent linear motion stability and curve passing ability for railway vehicles,research on the rubber-liquid composite swing arm node was carried out. The longitudinal stiffness of the swing arm node was changed by the flow of liquid in the compression chamber. The structural design of the rubber-liquid composite swing arm node was completed,its working principle was analyzed,and a theoretical model was established. Stiffness performance and fatigue characteristic tests were conducted using a test device. The results show that the dynamic-static stiffness ratio of the rubber-liquid composite swing arm node reaches 4.5,and the stiffness is significantly affected by the excitation frequency. The dynamic stiffness test curve is in good agreement with the theoretical calculation results. Liquid leakage can significantly reduce the dynamic stiffness characteristics of the rubber-liquid composite node. A pressure sensor can be embedded in the hydraulic chamber to monitor the internal pressure in real time to determine whether the swing arm node is leaking. After 12 million fatigue tests,the maximum decrease in the dynamic-static ratio was 10.7%,and no leakage or rubber aging was found. It still maintained good stiffness performance under high-frequency conditions,effectively verifying that the rubber-liquid composite swing arm node has excellent fatigue durability.
Optimization Design of Connecting Rod of Diesel Engine Based on Response Surface Method
LI Minghai;MAO Junhao;ZHAO Hailong;WANG Wenqing;In response to the lightweight and high-strength design requirements of a certain type of diesel engine connecting rod,the structural optimization design of the connecting rod was carried out based on the response surface method combined with finite element analysis. Firstly,the force conditions under extreme working conditions were solved according to the motion characteristics of the connecting rod,providing boundary conditions for subsequent strength analysis. Secondly,static analysis and modal solution of the connecting rod were conducted,and the results showed that the existing connecting rod had high strength,large material redundancy,a high first-order natural frequency,no resonance risk,and a large structural optimization space. Finally,with the lightest mass of the connecting rod body as the optimization objective and static strength and fatigue strength indicators as constraint conditions,the response surface method was used to optimize the structure of the connecting rod. After optimization,the mass of the connecting rod body decreased from 43.814 kg to 40.623 kg,a reduction of 7.28%; the maximum equivalent stress decreased from 306.23 MPa to 293.33 MPa,a reduction of 4.21%,and the fatigue life and first-order natural frequency both increased slightly. This study achieved the expected optimization goals of lightweight and high strength for the connecting rod,and provided a reference for the structural optimization design of similar connecting rod-type components.
Spatial Stress Analysis of No.0 Block of Variable Cross-Section Corrugated Steel Web Composite Box Girder Bridge
YANG Jianxi;LI Zhendong;MA Chi;LIU Xing'an;To study the complex stress distribution law of the No.0 block during the construction stage of the corrugated steel web composite box girder bridge,the Liu Jiazuizi corrugated steel web composite continuous box girder bridge in Guyuan City,Ningxia was taken as the research object. The overall finite element model of the bridge and the local refined finite element calculation model of the No.0 block were established respectively by using Midas Civil and ANSYS software,and verified by the field measured data. The spatial stress distribution characteristics of the No.0 block during the construction stage were analyzed. The calculation results show that the displacements of the top and bottom slabs of the composite box girder are symmetrically distributed along the center line of the section at different construction stages; the No.0 block is in a three-dimensional stress state,and the longitudinal and transverse stress distribution laws of the beam section are complex; in working conditions 1 to 4,the longitudinal and transverse stresses at the characteristic points of the cross-sections at x=0 and x=±3.2 m are basically symmetrically distributed along the center line of the section. Concrete at the connection between the corrugated steel web and the top slab shows transverse tensile stress in each working condition,among which the maximum tensile stress in working condition 1 is 1.79 MPa,approaching the allowable tensile stress,with insufficient safety reserve.