Since it's made up of over 7,000 islands,the Philippines is not a nation with a well‑developed railway transportation.That means coach buses are going to be your best bet for getting city‑to‑city.There is a small ...Since it's made up of over 7,000 islands,the Philippines is not a nation with a well‑developed railway transportation.That means coach buses are going to be your best bet for getting city‑to‑city.There is a small light rail system called the Light Rail Transit(LRT)in the Metro Manila area,but it's desperately inefficient.展开更多
Considering the difference in driving parameters of buses and social vehicles on the arterial,an arterial traffic signal coordination model that takes into account social vehicles and buses on the basis of the maximum...Considering the difference in driving parameters of buses and social vehicles on the arterial,an arterial traffic signal coordination model that takes into account social vehicles and buses on the basis of the maximum bandwidth is proposed.By using the pre-set parameters of a common cycle,green/red duration and known parameters of bus dwell time distribution,link length and vehicle speed and solving the mixed-integer-linear programming and optimizing the signal offsets,the model obtains the signal control parameters of the green bands both of social vehicles and buses.Finally,taking Wangjiang Road in Hefei as an example,simulation and evaluation are carried out by VISSIM.The results show that the new model has 15.2%and 13.2%reduction in average person delay and number of stops,respectively,compared with the traditional coordinated control method.展开更多
With the continuous development of urban public transportation, the harmful GHG emissions and pollutants generated by itself and the consequent issues such as the losses of residents’ health, economic value and resid...With the continuous development of urban public transportation, the harmful GHG emissions and pollutants generated by itself and the consequent issues such as the losses of residents’ health, economic value and residents’ welfare have become the focus of social attention. In order to study the impacts of promoting new energy vehicles on public transportation pollution mitigation and residents’ health benefits, this paper adopts the LEAP model to build some scenarios that fulfill different development needs to quantitatively analyze the ownership of new energy buses, the reduction of pollutants and the losses of residents’ health welfare. It is concluded that promoting new energy buses comprehensively can significantly reduce the emissions of atmospheric pollutants and the economic losses of residents’ health, but cannot fully realize the targets of greenhouse gas reduction under Life Cycle Analysis.展开更多
The transit bus environment is considered one of the primary sources of transmission of the COVID-19(SARSCoV-2)virus.Modeling disease transmission in public buses remains a challenge,especially with uncertainties in p...The transit bus environment is considered one of the primary sources of transmission of the COVID-19(SARSCoV-2)virus.Modeling disease transmission in public buses remains a challenge,especially with uncertainties in passenger boarding,alighting,and onboard movements.Although there are initial findings on the effectiveness of some of the mitigation policies(such as face-covering and ventilation),evidence is scarce on how these policies could affect the onboard transmission risk under a realistic bus setting considering different headways,boarding and alighting patterns,and seating capacity control.This study examines the specific policy regimes that transit agencies implemented during early phases of the COVID-19 pandemic in USA,in which it brings crucial insights on combating current and future epidemics.We use an agent-based simulation model(ABSM)based on standard design characteristics for urban buses in USA and two different service frequency settings(10-min and 20-min headways).We find that wearing face-coverings(surgical masks)significantly reduces onboard transmission rates,from no mitigation rates of 85%in higher-frequency buses and 75%in lower-frequency buses to 12.5%.The most effective prevention outcome is the combination of KN-95 masks,open window policies,and half-capacity seating control during higher-frequency bus services,with an outcome of nearly 0%onboard infection rate.Our results advance understanding of COVID-19 risks in the urban bus environment and contribute to effective mitigation policy design,which is crucial to ensuring passenger safety.The findings of this study provide important policy implications for operational adjustment and safety protocols as transit agencies seek to plan for future emergencies.展开更多
The traf fic authority ofGuangzhou, capital of south China’s Guangdong Province ,recently announced that videocamer as would be installed in every city bus in order to assist with commuter safety .
If you have been in Beijing for any length of time, you will have come to realize that there are several modes of transportation available to commuters, all ofthem relatively in expensive, especially
Since the 1990’s, hydrogen has found broad use in the traffic segment. Compared with conventional ones, hydrogen fuelled vehicles, a new generation of clean vehicles, produce no pollutants, with higher energy efficie...Since the 1990’s, hydrogen has found broad use in the traffic segment. Compared with conventional ones, hydrogen fuelled vehicles, a new generation of clean vehicles, produce no pollutants, with higher energy efficiency. In today’s world where the pollution is tougher, the "Zero Pollution" fuel cell buses display展开更多
AUTONOMOUS buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart electric vehicle factories running at full speed...In recent years,Beijing has seen the emergence of a lar...AUTONOMOUS buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart electric vehicle factories running at full speed...In recent years,Beijing has seen the emergence of a large number of cutting-edge technology companies,confirming the city’s role as a melting pot of scientific innovation in China.展开更多
With a boom in its science and technology sector,Beijing is establishing itself as a hotbed of innovation Autonomous buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart ...With a boom in its science and technology sector,Beijing is establishing itself as a hotbed of innovation Autonomous buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart electric vehicle factories running at full speed…In recent years,Beijing has seen the emergence of a large number of cutting-edge technology companies,confirming the city’s role as a melting pot of scientific innovation in China.展开更多
Designed and built by eight Dutch engineers,the worlds longest bicycle is 55.16 meters,roughly the same length as four double-decker buses.39-year-old Ivan Schalk had been thinking about building the world's longe...Designed and built by eight Dutch engineers,the worlds longest bicycle is 55.16 meters,roughly the same length as four double-decker buses.39-year-old Ivan Schalk had been thinking about building the world's longest bicycle since reading about it in The Guinness Book of Records when he was a child,but he only started this project in 2018,as a way to fill up his free time.展开更多
As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft ele...As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.展开更多
On-chip global buses in deep sub-micron designs consume significant amounts of energy and have large propagation delays. Thus, minimizing energy dissipation and propagation delay is an important design objective. In t...On-chip global buses in deep sub-micron designs consume significant amounts of energy and have large propagation delays. Thus, minimizing energy dissipation and propagation delay is an important design objective. In this paper, we propose a new spatial and temporal encoding approach for generic on-chip global buses with repeaters that enables higher performance while reducing peak energy and average energy. The proposed encoding approach exploits the benefits of a temporal encoding circuit and spatial bus-invert coding techniques to simultaneously eliminate opposite transitions on adjacent wires and reduce the number of self-transitions and coupling-transitions. In the design process of applying encoding techniques for reduced bus delay and energy, we present a repeater insertion design methodology to determine the repeater size and inter-repeater bus length, which minimizes the total bus energy dissipation while satisfying target delay and slew-rate constraints. This methodology is employed to obtain optimal energy versus delay trade-offs under slew-rate constraints for various encoding techniques.展开更多
Busing potential function has been used for the computer simulation of ZnCl2 melts. The agreement between the calculated values of inter-ionicc distances and total internal energy with the experimental data are rather...Busing potential function has been used for the computer simulation of ZnCl2 melts. The agreement between the calculated values of inter-ionicc distances and total internal energy with the experimental data are rather good.展开更多
A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，...A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly，the relative sensitivity index（RSI）is calculated to identify weak buses during analysis.Finally，case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability，expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.展开更多
Perth’s new 72 km long Southern Rail System opened in 2007. With a maximum speed of 137 km/hr and an average speed of almost 90 km/hr this system acts more like a new high speed rail than a suburban rail system, whic...Perth’s new 72 km long Southern Rail System opened in 2007. With a maximum speed of 137 km/hr and an average speed of almost 90 km/hr this system acts more like a new high speed rail than a suburban rail system, which in Australia typically averages around 40 km/hr for an all-stops services. The Southern Rail Line was very controversial when being planned as the urban areas served are not at all typical of those normally provided with rail but instead were highly car dependent and scattered low density land uses. Nevertheless it has been remarkably successful, carrying over 70,000 people per day (five times the patronage on the express buses it replaced) and has reached the patronage levels predicted for 2021 a decade ahead of time. The reasons for this success are analyzed and include well-designed interchanges, careful integration of bus services, the use of integrated ticketing and fares without transfer penalties and, crucially the high speed of the system when compared to competing car based trips. The Southern Rail Line in effect explodes the current paradigm of transfer penalties, exposing this as a myth. The lessons for transport planning in low density cities are significant, and are explored further in the paper.展开更多
Bus systems provide a versatile form of public transportation with the flexibility to serve a variety of access needs throughout an urban area. Efficient operation of the public transport is a key factor for the impro...Bus systems provide a versatile form of public transportation with the flexibility to serve a variety of access needs throughout an urban area. Efficient operation of the public transport is a key factor for the improvement of living condition in Dhaka city. Transport service performance should be assessed from the passengers’ perspectives to evaluate these perceptions in transportation planning. The exploration of service quality of bus is essential in order to provide a better service in future. The objective of this research is to access overall customer satisfaction in public bus transport of Dhaka city. A questionnaire survey was conducted in five locations in Dhaka city. Bus users’ satisfaction was analyzed by discrete choice logit model towards quality, reliability, safety and security and service provided by buses functioning in Dhaka city. The result indicated that more than half of the respondents believed that the present condition of bus service is not satisfactory. In case of the quality of buses, people think that the body and sitting arrangement of the buses are uncomfortable. Regarding the safety and security condition, main three reasons of dissatisfaction of passengers’ are unsafe driving practices, poor boarding and alighting facilities and lack of law enforcing agencies surveillance. Reasons which make the service unsatisfactory include irregular service provided by buses, regular overcrowding, lack of good standard buses and lack of cleanliness. In spite of these negative views, users’ possessed a positive attitude for buses which is the low travel cost.展开更多
Electric vehicles(EVs)have received special consideration from modern society over the past several years.Although EVs are a fine example of environmentally friendly technology and have many advantages,they relatively...Electric vehicles(EVs)have received special consideration from modern society over the past several years.Although EVs are a fine example of environmentally friendly technology and have many advantages,they relatively increase the electricity demand upon a power grid as well.Therefore,their negative impact on busvoltage and line losses should be analyzed.In this study,the effect of EV loads and their penetration on bus voltage and line losses of an IEEE-33 bussystem has been examined via two scenarios.It is important to mention that the effect of EVs on the rate of air pollution,produced by fossil fuel electricity generators,has been investigated throughout the study.Also,the key role of demand response programs in the reduction of EVs’negative effects on the grid has also been discussed in the last scenario.Generally,the simulation of this paper provides a novel and wider perspective on EVs and their effect on grids and environmental pollution.展开更多
This paper proposed a design of the drivetmin system of an electric bus with ultraeapacitor （UC） as the only on-board power source. The system includes three main parts, namely, UC bank, motor and the converter, veh...This paper proposed a design of the drivetmin system of an electric bus with ultraeapacitor （UC） as the only on-board power source. The system includes three main parts, namely, UC bank, motor and the converter, vehicle management unit （VMU）. Analyses results in detail on the funetional design and ex-periments on work bench of each part were also presented, which validated the reliability of the system. Furthermore, driving results in field of the bus verified the feasibility of the design of the drivetrain sys-tem. The bus has very good dynamic performanees and shows a promising applieations prospeet in the short and medium route buses system.展开更多
文摘Since it's made up of over 7,000 islands,the Philippines is not a nation with a well‑developed railway transportation.That means coach buses are going to be your best bet for getting city‑to‑city.There is a small light rail system called the Light Rail Transit(LRT)in the Metro Manila area,but it's desperately inefficient.
基金The National Natural Science Foundation of China(No.51878236)。
文摘Considering the difference in driving parameters of buses and social vehicles on the arterial,an arterial traffic signal coordination model that takes into account social vehicles and buses on the basis of the maximum bandwidth is proposed.By using the pre-set parameters of a common cycle,green/red duration and known parameters of bus dwell time distribution,link length and vehicle speed and solving the mixed-integer-linear programming and optimizing the signal offsets,the model obtains the signal control parameters of the green bands both of social vehicles and buses.Finally,taking Wangjiang Road in Hefei as an example,simulation and evaluation are carried out by VISSIM.The results show that the new model has 15.2%and 13.2%reduction in average person delay and number of stops,respectively,compared with the traditional coordinated control method.
文摘With the continuous development of urban public transportation, the harmful GHG emissions and pollutants generated by itself and the consequent issues such as the losses of residents’ health, economic value and residents’ welfare have become the focus of social attention. In order to study the impacts of promoting new energy vehicles on public transportation pollution mitigation and residents’ health benefits, this paper adopts the LEAP model to build some scenarios that fulfill different development needs to quantitatively analyze the ownership of new energy buses, the reduction of pollutants and the losses of residents’ health welfare. It is concluded that promoting new energy buses comprehensively can significantly reduce the emissions of atmospheric pollutants and the economic losses of residents’ health, but cannot fully realize the targets of greenhouse gas reduction under Life Cycle Analysis.
文摘The transit bus environment is considered one of the primary sources of transmission of the COVID-19(SARSCoV-2)virus.Modeling disease transmission in public buses remains a challenge,especially with uncertainties in passenger boarding,alighting,and onboard movements.Although there are initial findings on the effectiveness of some of the mitigation policies(such as face-covering and ventilation),evidence is scarce on how these policies could affect the onboard transmission risk under a realistic bus setting considering different headways,boarding and alighting patterns,and seating capacity control.This study examines the specific policy regimes that transit agencies implemented during early phases of the COVID-19 pandemic in USA,in which it brings crucial insights on combating current and future epidemics.We use an agent-based simulation model(ABSM)based on standard design characteristics for urban buses in USA and two different service frequency settings(10-min and 20-min headways).We find that wearing face-coverings(surgical masks)significantly reduces onboard transmission rates,from no mitigation rates of 85%in higher-frequency buses and 75%in lower-frequency buses to 12.5%.The most effective prevention outcome is the combination of KN-95 masks,open window policies,and half-capacity seating control during higher-frequency bus services,with an outcome of nearly 0%onboard infection rate.Our results advance understanding of COVID-19 risks in the urban bus environment and contribute to effective mitigation policy design,which is crucial to ensuring passenger safety.The findings of this study provide important policy implications for operational adjustment and safety protocols as transit agencies seek to plan for future emergencies.
文摘The traf fic authority ofGuangzhou, capital of south China’s Guangdong Province ,recently announced that videocamer as would be installed in every city bus in order to assist with commuter safety .
文摘If you have been in Beijing for any length of time, you will have come to realize that there are several modes of transportation available to commuters, all ofthem relatively in expensive, especially
文摘Since the 1990’s, hydrogen has found broad use in the traffic segment. Compared with conventional ones, hydrogen fuelled vehicles, a new generation of clean vehicles, produce no pollutants, with higher energy efficiency. In today’s world where the pollution is tougher, the "Zero Pollution" fuel cell buses display
文摘AUTONOMOUS buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart electric vehicle factories running at full speed...In recent years,Beijing has seen the emergence of a large number of cutting-edge technology companies,confirming the city’s role as a melting pot of scientific innovation in China.
文摘With a boom in its science and technology sector,Beijing is establishing itself as a hotbed of innovation Autonomous buses gliding through the streets,satellites with flexible solar wings whizzing through space,smart electric vehicle factories running at full speed…In recent years,Beijing has seen the emergence of a large number of cutting-edge technology companies,confirming the city’s role as a melting pot of scientific innovation in China.
文摘Designed and built by eight Dutch engineers,the worlds longest bicycle is 55.16 meters,roughly the same length as four double-decker buses.39-year-old Ivan Schalk had been thinking about building the world's longest bicycle since reading about it in The Guinness Book of Records when he was a child,but he only started this project in 2018,as a way to fill up his free time.
文摘As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.
文摘On-chip global buses in deep sub-micron designs consume significant amounts of energy and have large propagation delays. Thus, minimizing energy dissipation and propagation delay is an important design objective. In this paper, we propose a new spatial and temporal encoding approach for generic on-chip global buses with repeaters that enables higher performance while reducing peak energy and average energy. The proposed encoding approach exploits the benefits of a temporal encoding circuit and spatial bus-invert coding techniques to simultaneously eliminate opposite transitions on adjacent wires and reduce the number of self-transitions and coupling-transitions. In the design process of applying encoding techniques for reduced bus delay and energy, we present a repeater insertion design methodology to determine the repeater size and inter-repeater bus length, which minimizes the total bus energy dissipation while satisfying target delay and slew-rate constraints. This methodology is employed to obtain optimal energy versus delay trade-offs under slew-rate constraints for various encoding techniques.
文摘Busing potential function has been used for the computer simulation of ZnCl2 melts. The agreement between the calculated values of inter-ionicc distances and total internal energy with the experimental data are rather good.
基金This work is supported by National Natural Science Foundation of China （No. 50977051 ） and Research Project of Science and Technology from Shenzhen Development and Innovation Committee （No. ZDSY20120619141142918）.
文摘A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly，the relative sensitivity index（RSI）is calculated to identify weak buses during analysis.Finally，case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability，expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.
文摘Perth’s new 72 km long Southern Rail System opened in 2007. With a maximum speed of 137 km/hr and an average speed of almost 90 km/hr this system acts more like a new high speed rail than a suburban rail system, which in Australia typically averages around 40 km/hr for an all-stops services. The Southern Rail Line was very controversial when being planned as the urban areas served are not at all typical of those normally provided with rail but instead were highly car dependent and scattered low density land uses. Nevertheless it has been remarkably successful, carrying over 70,000 people per day (five times the patronage on the express buses it replaced) and has reached the patronage levels predicted for 2021 a decade ahead of time. The reasons for this success are analyzed and include well-designed interchanges, careful integration of bus services, the use of integrated ticketing and fares without transfer penalties and, crucially the high speed of the system when compared to competing car based trips. The Southern Rail Line in effect explodes the current paradigm of transfer penalties, exposing this as a myth. The lessons for transport planning in low density cities are significant, and are explored further in the paper.
文摘Bus systems provide a versatile form of public transportation with the flexibility to serve a variety of access needs throughout an urban area. Efficient operation of the public transport is a key factor for the improvement of living condition in Dhaka city. Transport service performance should be assessed from the passengers’ perspectives to evaluate these perceptions in transportation planning. The exploration of service quality of bus is essential in order to provide a better service in future. The objective of this research is to access overall customer satisfaction in public bus transport of Dhaka city. A questionnaire survey was conducted in five locations in Dhaka city. Bus users’ satisfaction was analyzed by discrete choice logit model towards quality, reliability, safety and security and service provided by buses functioning in Dhaka city. The result indicated that more than half of the respondents believed that the present condition of bus service is not satisfactory. In case of the quality of buses, people think that the body and sitting arrangement of the buses are uncomfortable. Regarding the safety and security condition, main three reasons of dissatisfaction of passengers’ are unsafe driving practices, poor boarding and alighting facilities and lack of law enforcing agencies surveillance. Reasons which make the service unsatisfactory include irregular service provided by buses, regular overcrowding, lack of good standard buses and lack of cleanliness. In spite of these negative views, users’ possessed a positive attitude for buses which is the low travel cost.
文摘Electric vehicles(EVs)have received special consideration from modern society over the past several years.Although EVs are a fine example of environmentally friendly technology and have many advantages,they relatively increase the electricity demand upon a power grid as well.Therefore,their negative impact on busvoltage and line losses should be analyzed.In this study,the effect of EV loads and their penetration on bus voltage and line losses of an IEEE-33 bussystem has been examined via two scenarios.It is important to mention that the effect of EVs on the rate of air pollution,produced by fossil fuel electricity generators,has been investigated throughout the study.Also,the key role of demand response programs in the reduction of EVs’negative effects on the grid has also been discussed in the last scenario.Generally,the simulation of this paper provides a novel and wider perspective on EVs and their effect on grids and environmental pollution.
文摘This paper proposed a design of the drivetmin system of an electric bus with ultraeapacitor （UC） as the only on-board power source. The system includes three main parts, namely, UC bank, motor and the converter, vehicle management unit （VMU）. Analyses results in detail on the funetional design and ex-periments on work bench of each part were also presented, which validated the reliability of the system. Furthermore, driving results in field of the bus verified the feasibility of the design of the drivetrain sys-tem. The bus has very good dynamic performanees and shows a promising applieations prospeet in the short and medium route buses system.
