The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independe...The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independent cognitive understanding stage(i.e.deep learning)has become the focus of geography teaching.Therefore,under the guidance of deep learning theory,this paper takes the“landforms”knowledge unit of the Humanistic Education Edition as an example,improves the classroom teaching means through the unit teaching mode,reconstructs the“landforms”teaching unit,and explores the specific teaching of high school geography unit based on deep learning.This study provides a good example and guidelines for high school geography teaching and learning.展开更多
With increase of train speed,braking plate technology has a good application prospect in the high-speed stage of the train.Based on the 1/8 scaled symmetrical train model composed of two half cars,the Reynolds Av era ...With increase of train speed,braking plate technology has a good application prospect in the high-speed stage of the train.Based on the 1/8 scaled symmetrical train model composed of two half cars,the Reynolds Av era ge Navier-Stokes(RANS)equations and Shear Stress Transfer(SST)k-ωturbulence model are adopted to simulate the aerodynamic performance of the train with plate.The aer odynamic dra g de pendence of single par ameter of the plate(shape,area,angle,position and n umber)is anal ysed,and identification resear c h of the main aerodynamic parameters of the plate is carried out.The numerical settings used in this paper are verified by wind tunnel test data.Results show that the braking plate with an aspect ratio of one has better performance on aerodynamic drag.The area,opening angle and number of plates are basically positively correlated with the total aerodynamic drag of the target car and plate.Arr anging plates at the downstream of the vehicle is a good method of raising total aerodynamic drag.Within the range of plate parameter design in this paper,by using orthogonal design of experiment and the method of range analysis and analysis of variance,the influence degrees of plate parameters on aer odynamic dra g ar e determined,and the order is n umber,ar ea and opening angle of plate.The research results provide theoretical support for the design and safe operation of high-speed trains with aerodynamic braking plates.展开更多
The coupling and complexity of railway train/tunnel system are further aggravated by increasing train speed,which produces a series of aerodynamics problems,such as aerodynamic drag,slipstream,pressure wave and micro ...The coupling and complexity of railway train/tunnel system are further aggravated by increasing train speed,which produces a series of aerodynamics problems,such as aerodynamic drag,slipstream,pressure wave and micro pressure wave.Aerodynamic effects of tunnels will result in a significant increase in train energy consump-tion,shorten life of railway train/tunnel system,and increase maintenance cost.This paper provides a review of aerodynamics of railway train/tunnel system.Challenges in railway train/tunnel system aerodynamics and their related factors are discussed firstly.Aerodynamic performance and flow field characteristics of trains in tunnels are presented.Relationship of aerodynamic effects and parameters of railway train/tunnel system,and the control methods for reducing aerodynamic effects in tunnels are explained.A traffic safety evaluation of the train in tunnels,such as vehicle body structure,passengers’ear comfort,etc.,is introduced and analysed.Finally,future outlooks and research topics are proposed.展开更多
Travel recommendations form a major part of tourism service. Traditional collaborative filtering and Markov model are not appropriate for expressing the trajectory features,for travel preferences of tourists are dynam...Travel recommendations form a major part of tourism service. Traditional collaborative filtering and Markov model are not appropriate for expressing the trajectory features,for travel preferences of tourists are dynamic and affected by previous behaviors. Inspired by the success of deep learning in sequence learning,a personalized recurrent neural network (P-RecN) is proposed for tourist route recommendation. It is data-driven and adaptively learns the unknown mapping of historical trajectory input to recommended route output. Specifically,a trajectory encoding module is designed to mine the semantic information of trajectory data,and LSTM neural networks are used to capture the sequence travel patterns of tourists. In particular,a temporal attention mechanism is integrated to emphasize the main behavioral intention of tourists. We retrieve a geotagged photo dataset in Shanghai,and evaluate our model in terms of accuracy and ranking ability. Experimental results illustrated that P-RecN outperforms other baseline approaches and can effectively understand the travel patterns of tourists.展开更多
文摘The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independent cognitive understanding stage(i.e.deep learning)has become the focus of geography teaching.Therefore,under the guidance of deep learning theory,this paper takes the“landforms”knowledge unit of the Humanistic Education Edition as an example,improves the classroom teaching means through the unit teaching mode,reconstructs the“landforms”teaching unit,and explores the specific teaching of high school geography unit based on deep learning.This study provides a good example and guidelines for high school geography teaching and learning.
基金supported by the National Natural Science Foundation of China (Grant No.52172359)the Foundation of Maglev Technology Key Labor atory of Rail way Industry,Sichuan Science and Technology Program (Grant No.2020JDTD0012).
文摘With increase of train speed,braking plate technology has a good application prospect in the high-speed stage of the train.Based on the 1/8 scaled symmetrical train model composed of two half cars,the Reynolds Av era ge Navier-Stokes(RANS)equations and Shear Stress Transfer(SST)k-ωturbulence model are adopted to simulate the aerodynamic performance of the train with plate.The aer odynamic dra g de pendence of single par ameter of the plate(shape,area,angle,position and n umber)is anal ysed,and identification resear c h of the main aerodynamic parameters of the plate is carried out.The numerical settings used in this paper are verified by wind tunnel test data.Results show that the braking plate with an aspect ratio of one has better performance on aerodynamic drag.The area,opening angle and number of plates are basically positively correlated with the total aerodynamic drag of the target car and plate.Arr anging plates at the downstream of the vehicle is a good method of raising total aerodynamic drag.Within the range of plate parameter design in this paper,by using orthogonal design of experiment and the method of range analysis and analysis of variance,the influence degrees of plate parameters on aer odynamic dra g ar e determined,and the order is n umber,ar ea and opening angle of plate.The research results provide theoretical support for the design and safe operation of high-speed trains with aerodynamic braking plates.
基金supported by the National Natural Science Foun-dation of China(51805453,51978575,and 51975487)the Funda-mental Research Funds for the Central Universities(2682018CX14)the Project funded by China Postdoctoral Science Foundation(2019M663551).
文摘The coupling and complexity of railway train/tunnel system are further aggravated by increasing train speed,which produces a series of aerodynamics problems,such as aerodynamic drag,slipstream,pressure wave and micro pressure wave.Aerodynamic effects of tunnels will result in a significant increase in train energy consump-tion,shorten life of railway train/tunnel system,and increase maintenance cost.This paper provides a review of aerodynamics of railway train/tunnel system.Challenges in railway train/tunnel system aerodynamics and their related factors are discussed firstly.Aerodynamic performance and flow field characteristics of trains in tunnels are presented.Relationship of aerodynamic effects and parameters of railway train/tunnel system,and the control methods for reducing aerodynamic effects in tunnels are explained.A traffic safety evaluation of the train in tunnels,such as vehicle body structure,passengers’ear comfort,etc.,is introduced and analysed.Finally,future outlooks and research topics are proposed.
基金supported in part by the National Natural Science Foundation of China (42171460)the Open Fund of Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution,Xinyang Normal University (KLSPWSEP-A09).
文摘Travel recommendations form a major part of tourism service. Traditional collaborative filtering and Markov model are not appropriate for expressing the trajectory features,for travel preferences of tourists are dynamic and affected by previous behaviors. Inspired by the success of deep learning in sequence learning,a personalized recurrent neural network (P-RecN) is proposed for tourist route recommendation. It is data-driven and adaptively learns the unknown mapping of historical trajectory input to recommended route output. Specifically,a trajectory encoding module is designed to mine the semantic information of trajectory data,and LSTM neural networks are used to capture the sequence travel patterns of tourists. In particular,a temporal attention mechanism is integrated to emphasize the main behavioral intention of tourists. We retrieve a geotagged photo dataset in Shanghai,and evaluate our model in terms of accuracy and ranking ability. Experimental results illustrated that P-RecN outperforms other baseline approaches and can effectively understand the travel patterns of tourists.
