To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and str...To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.展开更多
Local climate zones(LCZs)are an effective nexus linking internal urban structures to the local climate and have been widely used to study urban thermal environment.However,few studies considered how much the temperatu...Local climate zones(LCZs)are an effective nexus linking internal urban structures to the local climate and have been widely used to study urban thermal environment.However,few studies considered how much the temperature changed due to LCZs transformation and their synergy.This paper quantified the change of urban land surface temperature(LST)in LCZs transformation process by combining the land use transfer matrix with zonal statistics method during 2000–2019 in the Xi’an metropolitan.The results show that,firstly,both LCZs and LST had significant spatiotemporal variations and synchrony.The period when the most LCZs were converted was also the LST rose the fastest,and the spatial growth of the LST coincided with the spatial expansion of the built type LCZs.Secondly,the LST difference between land cover type LCZs and built type LCZs gradually widened.And LST rose more in both built type LCZs transferred in and out.Finally,the Xi’an-Xianyang profile showed that the maximum temperature difference between the peaks and valleys of the LST increased by 4.39℃,indicating that localized high temperature phenomena and fluctuations in the urban thermal environment became more pronounced from 2000 to 2019.展开更多
Purpose-This study aims to improve the passenger accessibility of passenger demands in the end-ofoperation period.Design/methodology/approach-A mixed integer nonlinear programming model for last train timetable optim...Purpose-This study aims to improve the passenger accessibility of passenger demands in the end-ofoperation period.Design/methodology/approach-A mixed integer nonlinear programming model for last train timetable optimization of the metro was proposed considering the constraints such as the maximum headway,the minimum headway and the latest end-of-operation time.The objective of the model is to maximize the number of reachable passengers in the end-of-operation period.A solution method based on a preset train service is proposed,which significantly reduces the variables of deciding train services in the original model and reformulates it into a mixed integer linear programming model.Findings-The results of the case study of Wuhan Metro show that the solution method can obtain highquality solutions in a shorter time;and the shorter the time interval of passenger flow data,the more obvious the advantage of solution speed;after optimization,the number of passengers reaching the destination among the passengers who need to take the last train during the end-of-operation period can be increased by 10%.Originality/value-Existing research results only consider the passengers who take the last train.Compared with previous research,considering the overall passenger demand during the end-of-operation period can make more passengers arrive at their destination.Appropriately delaying the end-of-operation time can increase the proportion of passengers who can reach the destination in the metro network,but due to the decrease in passenger demand,postponing the end-of-operation time has a bottleneck in increasing the proportion of passengers who can reach the destination.展开更多
In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strat...In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strategy is proposed.Firstly,the construction of the hybrid regenerative braking energy recovery system is explained.Then,based on the power demand of low-voltage load in metro stations,a dual-mode power management strategy is proposed to allocate the reference power of each system according to the different working conditions,and the control methods of each system are set.Finally,the correctness and effectiveness of the dual-mode strategy are verified through simulation,and the proposed braking energy utilization scheme is compared with other singleform utilization schemes.The results illustrate that the hybrid system with the dual-mode strategy can effectively recycle the regenerative braking energy of metro train and inhibit the busbar voltage fluctuation;the proposed braking energy utilization scheme has certain advantages on energy recovery and DC bus voltage stabilization compared with other single-form schemes;the proposed power management strategy can correctly allocate the reference power of each system with a lower construction cost.展开更多
Amid the increasingly severe global natural eco-environment,it is necessary to build a natural ecological civilization by constructing an ecological civilization discourse.Against this background,this study compiles a...Amid the increasingly severe global natural eco-environment,it is necessary to build a natural ecological civilization by constructing an ecological civilization discourse.Against this background,this study compiles a corpus of natural ecological discourse in the English translation of Xi Jinping:The Governance of China(short for Xi).By using Wordsmith and AntConc,this study explores the linguistic features of the ecological discourse in English translation of Xi in the following dimensions,including high-frequency words,keywords,word collocations,concordance lines.This study aims to analyze the concepts and attitudes towards natural ecology,so as to provide certain valuable insights for the construction of China’s discourse on natural ecological civilization.The study found that the natural ecology discourse involving in the English translation of Xi turned out to be ecologically beneficial.展开更多
The metro is the most efficient and convenient public transport system in modern cities. For urban core areas in China, in which the metro was built later, there was more consideration for meeting the traffic needs of...The metro is the most efficient and convenient public transport system in modern cities. For urban core areas in China, in which the metro was built later, there was more consideration for meeting the traffic needs of cities. However, there are few studies of collaborative planning for metro stations and their surrounding space. Thus, there is an urgent need to conduct research on collaborative planning for metro stations and their surrounding commercial space in urban core areas. Unlike conventional methods of integrated design of stations and cities, this paper, based on the theory of place spirit, took Chunxi Road Metro Station in Chengdu and its surrounding commercial space for example. It explored the pattern and characteristics of the place in the commercial space around the metro station, analyzed the strategies of cultural and commercial integration, as well as architecture, street, landscape and other aspects of the design method in the space, and explored the strategies of place-making and infiltration, providing a reference point for the development and place-making of the commercial space around metro stations in urban core areas.展开更多
In ancient China, Daoist philosophers developed the concepts of qi(energy), Wu Xing(five elements), and yin(feminine, dark, negative) and yang(masculine, bright, positive) opposite forces between 200 and 600 BCE. Base...In ancient China, Daoist philosophers developed the concepts of qi(energy), Wu Xing(five elements), and yin(feminine, dark, negative) and yang(masculine, bright, positive) opposite forces between 200 and 600 BCE. Based on these philosophies, Zhen Jiu(acupuncture), Ben Cao(materia medica), and the practice of Qi Gong(energy optimization movements) evolved as the three interrelated therapeutic regimens of Chinese medicine(Note 1). Since the time of Zhang Qian, who discovered China's western regions in the 1st century BCE, Hai Yao(the exotic elements of materia medica from the maritime Silk Road countries), had been transmitted from the ancient land and maritime routes of the Silk Road to China in the past two millennia(Note 2). Since the late 17th century, the English East India Company, later called the British East India Company, introduced Yang Yao(opium) to the Manchu Qing Empire to balance a growing trade deficit for tea export from China to the British Empire. After the First Opium War ended in 1842, enterprising expatriate chemists and druggists in the treaty ports imported Xi Yao(modern medicines from the Western world) for sale to the merchant navy and the local market. From the second half of the 19th century onwards, both Hai Yao and Xi Yao have become a fully integrated part of modern China's armamentarium for the Chinese medicine and Western hospitals and retail pharmacy sectors. This paper articulates the journey of adoption of exotic elements of materia medica from the ancient land and sea routes of the Silk Road, including the western regions and the rest of the world in the past two millennia. Opium traders, ship surgeons, medical and pharmaceutical missionaries, enterprising traders, and policymakers together transformed Ben Cao into Xi Yao during the late Manchu Qing dynasty and the early Nationalist Era.展开更多
For Xi'an,the central city of the Silk Road Economic Belt,it is both the theoretical and practical problem to develop into an international metropolis,so how to develop into an international metropolis becomes the...For Xi'an,the central city of the Silk Road Economic Belt,it is both the theoretical and practical problem to develop into an international metropolis,so how to develop into an international metropolis becomes the research focus. This paper firstly introduces the necessity,the current situation and the evaluation index system of the construction of the city Xi'an in the context of the Silk Road Economic Belt; then it analyzes the econom ic developm ent of the three old districts,the three new districts,the three suburban districts and the four counties; and finally it puts forward the development path for Xi'an in the context of the Silk Road Economic Belt — the development pattern of "five districts,one international harbor area and two bases""nine-grid-pattern "economic development and the function-oriented coordinated development of the regional economy.展开更多
Railway turnout is one of the critical equipment of Switch&Crossing(S&C)Systems in railway,related to the train’s safety and operation efficiency.With the advancement of intelligent sensors,data-driven fault ...Railway turnout is one of the critical equipment of Switch&Crossing(S&C)Systems in railway,related to the train’s safety and operation efficiency.With the advancement of intelligent sensors,data-driven fault detection technology for railway turnout has become an important research topic.However,little research in the literature has investigated the capability of data-driven fault detection technology for metro railway turnout.This paper presents a convolutional autoencoder-based fault detection method for the metro railway turnout considering human field inspection scenarios.First,the one-dimensional original time-series signal is converted into a twodimensional image by data pre-processing and 2D representation.Next,a binary classification model based on the convolutional autoencoder is developed to implement fault detection.The profile and structure information can be captured by processing data as images.The performance of our method is evaluated and tested on real-world operational current data in themetro stations.Experimental results show that the proposedmethod achieves better performance,especially in terms of error rate and specificity,and is robust in practical engineering applications.展开更多
China’s urbanization development has entered the“second half”,which is at a critical stage of transition from the middle stages to the mature stage.The metropolitan area formed by the mega-city radiating the develo...China’s urbanization development has entered the“second half”,which is at a critical stage of transition from the middle stages to the mature stage.The metropolitan area formed by the mega-city radiating the development of surrounding cities and counties is an important spatial carrier of urbanization.The rural characteristic industry is the main path to promote regional economic development and urban-rural integration in the metropolitan area.Exploring the development characteristics of rural characteristic industries in the metropolitan area has important theoretical and practical significance for promoting the effective connection between urban-rural integration and rural revitalization of the metropolitan area and improving the development quality of the metropolitan area.Take the Xi’an metropolitan area as an example and adopt kernel density analysis and other methods to reveal the spatial differentiation rules of rural characteristic industries.On this basis,the three-dimensional development strategy of“industry-spatial-institutional”for the development of the rural characteristic industry is proposed,to provide theoretical reference for the development of rural characteristic industry in metropolitan areas.展开更多
Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,...Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.展开更多
With advantages of strong drive capability,nested-loop secondary linear machine(NLS-LM)has great potentiality in linear metro.For its secondary structure with multiple loops,it is difficult to calculate the electromag...With advantages of strong drive capability,nested-loop secondary linear machine(NLS-LM)has great potentiality in linear metro.For its secondary structure with multiple loops,it is difficult to calculate the electromagnetic thrust of NLS-LM reasonably.Hence,in this paper,one thrust calculation method is proposed considering variable loop inductance and transient loop current.Firstly,to establish the secondary winding function,the modeling domain is confined to a limited range,and the equivalent loop span is employed by analyzing the coupling relationship between primary and secondary.Then,in order to obtain the secondary flux density,the transient secondary current is solved based on the loop impedance and induced voltage.Finally,the electromagnetic thrust can be calculated reasonably by the given primary current sheet and the calculated secondary flux density.Comprehensive simulations and experiments have demonstrated the effectiveness of the proposed method.展开更多
Guangzhou and Foshan enjoy relatively mature metro network.However,some names of metro stations are over-transliterated in Pinyin.Such a translation method is used in translating general names,nouns of locality and so...Guangzhou and Foshan enjoy relatively mature metro network.However,some names of metro stations are over-transliterated in Pinyin.Such a translation method is used in translating general names,nouns of locality and some names of tourist destinations.With translation landscape and linguistic landscape theories,the reasons and impacts of over-transliteration in Guangzhou and Foshan metro will be discussed from the perspective of symbolic function.English names of Metro stations in other cities serve as a reference so as to appropriate solutions.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:51878060,52078046。
文摘To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.
基金Under the auspices of National Natural Science Foundation of China(No.42271214,41961027)Key Program of Natural Science Foundation of Gansu Province(No.21JR7RA278,21JR7RA281)+1 种基金the CAS‘Light of West China’Program(No.2020XBZGXBQNXZ-A)Basic Research Top Talent Plan of Lanzhou Jiaotong University(No.2022JC01)。
文摘Local climate zones(LCZs)are an effective nexus linking internal urban structures to the local climate and have been widely used to study urban thermal environment.However,few studies considered how much the temperature changed due to LCZs transformation and their synergy.This paper quantified the change of urban land surface temperature(LST)in LCZs transformation process by combining the land use transfer matrix with zonal statistics method during 2000–2019 in the Xi’an metropolitan.The results show that,firstly,both LCZs and LST had significant spatiotemporal variations and synchrony.The period when the most LCZs were converted was also the LST rose the fastest,and the spatial growth of the LST coincided with the spatial expansion of the built type LCZs.Secondly,the LST difference between land cover type LCZs and built type LCZs gradually widened.And LST rose more in both built type LCZs transferred in and out.Finally,the Xi’an-Xianyang profile showed that the maximum temperature difference between the peaks and valleys of the LST increased by 4.39℃,indicating that localized high temperature phenomena and fluctuations in the urban thermal environment became more pronounced from 2000 to 2019.
基金supported by Talents Funds for Basic Scientific Research Business Expenses of Central Colleges and Universities (Grant No.2021RC228)Special Funds for Basic Scientific Research Business Expenses of Central Colleges and Universities (Grant No.2021YJS103).
文摘Purpose-This study aims to improve the passenger accessibility of passenger demands in the end-ofoperation period.Design/methodology/approach-A mixed integer nonlinear programming model for last train timetable optimization of the metro was proposed considering the constraints such as the maximum headway,the minimum headway and the latest end-of-operation time.The objective of the model is to maximize the number of reachable passengers in the end-of-operation period.A solution method based on a preset train service is proposed,which significantly reduces the variables of deciding train services in the original model and reformulates it into a mixed integer linear programming model.Findings-The results of the case study of Wuhan Metro show that the solution method can obtain highquality solutions in a shorter time;and the shorter the time interval of passenger flow data,the more obvious the advantage of solution speed;after optimization,the number of passengers reaching the destination among the passengers who need to take the last train during the end-of-operation period can be increased by 10%.Originality/value-Existing research results only consider the passengers who take the last train.Compared with previous research,considering the overall passenger demand during the end-of-operation period can make more passengers arrive at their destination.Appropriately delaying the end-of-operation time can increase the proportion of passengers who can reach the destination in the metro network,but due to the decrease in passenger demand,postponing the end-of-operation time has a bottleneck in increasing the proportion of passengers who can reach the destination.
基金funded by Project supported by the Natural Science Foundation of Gansu Province,China(Grant No.22JR5RA318).
文摘In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strategy is proposed.Firstly,the construction of the hybrid regenerative braking energy recovery system is explained.Then,based on the power demand of low-voltage load in metro stations,a dual-mode power management strategy is proposed to allocate the reference power of each system according to the different working conditions,and the control methods of each system are set.Finally,the correctness and effectiveness of the dual-mode strategy are verified through simulation,and the proposed braking energy utilization scheme is compared with other singleform utilization schemes.The results illustrate that the hybrid system with the dual-mode strategy can effectively recycle the regenerative braking energy of metro train and inhibit the busbar voltage fluctuation;the proposed braking energy utilization scheme has certain advantages on energy recovery and DC bus voltage stabilization compared with other single-form schemes;the proposed power management strategy can correctly allocate the reference power of each system with a lower construction cost.
文摘Amid the increasingly severe global natural eco-environment,it is necessary to build a natural ecological civilization by constructing an ecological civilization discourse.Against this background,this study compiles a corpus of natural ecological discourse in the English translation of Xi Jinping:The Governance of China(short for Xi).By using Wordsmith and AntConc,this study explores the linguistic features of the ecological discourse in English translation of Xi in the following dimensions,including high-frequency words,keywords,word collocations,concordance lines.This study aims to analyze the concepts and attitudes towards natural ecology,so as to provide certain valuable insights for the construction of China’s discourse on natural ecological civilization.The study found that the natural ecology discourse involving in the English translation of Xi turned out to be ecologically beneficial.
基金Sponsored by Technology Research Program of Sichuan Province of China(2016JY0111)
文摘The metro is the most efficient and convenient public transport system in modern cities. For urban core areas in China, in which the metro was built later, there was more consideration for meeting the traffic needs of cities. However, there are few studies of collaborative planning for metro stations and their surrounding space. Thus, there is an urgent need to conduct research on collaborative planning for metro stations and their surrounding commercial space in urban core areas. Unlike conventional methods of integrated design of stations and cities, this paper, based on the theory of place spirit, took Chunxi Road Metro Station in Chengdu and its surrounding commercial space for example. It explored the pattern and characteristics of the place in the commercial space around the metro station, analyzed the strategies of cultural and commercial integration, as well as architecture, street, landscape and other aspects of the design method in the space, and explored the strategies of place-making and infiltration, providing a reference point for the development and place-making of the commercial space around metro stations in urban core areas.
文摘In ancient China, Daoist philosophers developed the concepts of qi(energy), Wu Xing(five elements), and yin(feminine, dark, negative) and yang(masculine, bright, positive) opposite forces between 200 and 600 BCE. Based on these philosophies, Zhen Jiu(acupuncture), Ben Cao(materia medica), and the practice of Qi Gong(energy optimization movements) evolved as the three interrelated therapeutic regimens of Chinese medicine(Note 1). Since the time of Zhang Qian, who discovered China's western regions in the 1st century BCE, Hai Yao(the exotic elements of materia medica from the maritime Silk Road countries), had been transmitted from the ancient land and maritime routes of the Silk Road to China in the past two millennia(Note 2). Since the late 17th century, the English East India Company, later called the British East India Company, introduced Yang Yao(opium) to the Manchu Qing Empire to balance a growing trade deficit for tea export from China to the British Empire. After the First Opium War ended in 1842, enterprising expatriate chemists and druggists in the treaty ports imported Xi Yao(modern medicines from the Western world) for sale to the merchant navy and the local market. From the second half of the 19th century onwards, both Hai Yao and Xi Yao have become a fully integrated part of modern China's armamentarium for the Chinese medicine and Western hospitals and retail pharmacy sectors. This paper articulates the journey of adoption of exotic elements of materia medica from the ancient land and sea routes of the Silk Road, including the western regions and the rest of the world in the past two millennia. Opium traders, ship surgeons, medical and pharmaceutical missionaries, enterprising traders, and policymakers together transformed Ben Cao into Xi Yao during the late Manchu Qing dynasty and the early Nationalist Era.
基金the staged achievement of the special project of liberal arts of the social sciences fund of Xi’an(14wl08)
文摘For Xi'an,the central city of the Silk Road Economic Belt,it is both the theoretical and practical problem to develop into an international metropolis,so how to develop into an international metropolis becomes the research focus. This paper firstly introduces the necessity,the current situation and the evaluation index system of the construction of the city Xi'an in the context of the Silk Road Economic Belt; then it analyzes the econom ic developm ent of the three old districts,the three new districts,the three suburban districts and the four counties; and finally it puts forward the development path for Xi'an in the context of the Silk Road Economic Belt — the development pattern of "five districts,one international harbor area and two bases""nine-grid-pattern "economic development and the function-oriented coordinated development of the regional economy.
基金supported in part by the National Natural Science Foundation of China under Grant U1734211.
文摘Railway turnout is one of the critical equipment of Switch&Crossing(S&C)Systems in railway,related to the train’s safety and operation efficiency.With the advancement of intelligent sensors,data-driven fault detection technology for railway turnout has become an important research topic.However,little research in the literature has investigated the capability of data-driven fault detection technology for metro railway turnout.This paper presents a convolutional autoencoder-based fault detection method for the metro railway turnout considering human field inspection scenarios.First,the one-dimensional original time-series signal is converted into a twodimensional image by data pre-processing and 2D representation.Next,a binary classification model based on the convolutional autoencoder is developed to implement fault detection.The profile and structure information can be captured by processing data as images.The performance of our method is evaluated and tested on real-world operational current data in themetro stations.Experimental results show that the proposedmethod achieves better performance,especially in terms of error rate and specificity,and is robust in practical engineering applications.
基金Key R&D Plan of China’s“Fourteenth Five Year Plan for National Economic and Social Development”,subject number:2022YFC3800101funded by the Ministry of Education,the People’s Republic of China,grant number 20JZD012Xi’an University of Architecture and Technology,grant number 2022SCHZ05.
文摘China’s urbanization development has entered the“second half”,which is at a critical stage of transition from the middle stages to the mature stage.The metropolitan area formed by the mega-city radiating the development of surrounding cities and counties is an important spatial carrier of urbanization.The rural characteristic industry is the main path to promote regional economic development and urban-rural integration in the metropolitan area.Exploring the development characteristics of rural characteristic industries in the metropolitan area has important theoretical and practical significance for promoting the effective connection between urban-rural integration and rural revitalization of the metropolitan area and improving the development quality of the metropolitan area.Take the Xi’an metropolitan area as an example and adopt kernel density analysis and other methods to reveal the spatial differentiation rules of rural characteristic industries.On this basis,the three-dimensional development strategy of“industry-spatial-institutional”for the development of the rural characteristic industry is proposed,to provide theoretical reference for the development of rural characteristic industry in metropolitan areas.
基金This research was supported by the National Natural Science Foundation of China(Grant No.71971016).On behalf of all co-authors,the corresponding author states that there is no conflict of interest.
文摘Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.
基金supported in part by the National Natural Science Foundation of China under Grants 52277050the Shenzhen International Collaboration under Grant GJHZ20210705142539007。
文摘With advantages of strong drive capability,nested-loop secondary linear machine(NLS-LM)has great potentiality in linear metro.For its secondary structure with multiple loops,it is difficult to calculate the electromagnetic thrust of NLS-LM reasonably.Hence,in this paper,one thrust calculation method is proposed considering variable loop inductance and transient loop current.Firstly,to establish the secondary winding function,the modeling domain is confined to a limited range,and the equivalent loop span is employed by analyzing the coupling relationship between primary and secondary.Then,in order to obtain the secondary flux density,the transient secondary current is solved based on the loop impedance and induced voltage.Finally,the electromagnetic thrust can be calculated reasonably by the given primary current sheet and the calculated secondary flux density.Comprehensive simulations and experiments have demonstrated the effectiveness of the proposed method.
文摘Guangzhou and Foshan enjoy relatively mature metro network.However,some names of metro stations are over-transliterated in Pinyin.Such a translation method is used in translating general names,nouns of locality and some names of tourist destinations.With translation landscape and linguistic landscape theories,the reasons and impacts of over-transliteration in Guangzhou and Foshan metro will be discussed from the perspective of symbolic function.English names of Metro stations in other cities serve as a reference so as to appropriate solutions.