The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt.A high-level model was developed to predict vehicle fuel and electricity consum...The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt.A high-level model was developed to predict vehicle fuel and electricity consumption based on driving characteristics and vehicle state inputs.These techniques were leveraged to optimize energy efficiency via green routing and intelligent control mode scheduling,which were evaluated using prospective driving routes between tens of thousands of real-world origin/destination pairs.The overall energy savings potential of green routing and intelligent mode scheduling was estimated at 5%and 3%,respectively.These represent substantial opportunities considering that they only require software adjustments to implement.展开更多
Continuous vehicle tracking as well as monitoring driving behaviour, is significant services that are needed by manyindustries including insurance and vehicle rental companies. The main goal of this paper is to provid...Continuous vehicle tracking as well as monitoring driving behaviour, is significant services that are needed by manyindustries including insurance and vehicle rental companies. The main goal of this paper is to provide methods to model the quality ofthe driving behaviour based on FIS （fuzzy inference systems）. The models consider vehicle dynamics as long as the human behaviourparameters, expressed by a set of raw measurements which are obtained from various environmental sensors. In addition,assessment-driving behaviour model is simulated and tested by two different FISs： Mamdani and Sugeno-TSK. The simulation resultsillustrate the critical distinctions between the two FISs using the proposed driving behaviour models. These differences are based onvarious processing times, robust behaviour of the FISs, outputs MFs （membership functions）, fuzzification-techniques, flexibility inthe systems design and computational efficiency.展开更多
In this paper, a manufacturing supply chain system composed by a single-product machine, a buffer and a stochastic demand is considered. A stochastic fluid model is adopted to describe the system and to take into acco...In this paper, a manufacturing supply chain system composed by a single-product machine, a buffer and a stochastic demand is considered. A stochastic fluid model is adopted to describe the system and to take into account stochastic delivery times. The objective of this paper is to evaluate the optimal buffer level used in hedging point policy taken into account planned delivery times, machine failures and random demands. This optimal buffer allows minimizing the sum of inventory, transportation, lost sales and late delivery costs. Infinitesimal perturbation analysis method is used for optimizing the proposed system. Using the stochastic fluid model, the trajectories of buffer level are studied and the infinitesimal perturbation analysis estimators are evaluated. These estimators are shown to be unbiased and then they are implanted in an optimization algorithm, which determines the optimal buffer level in the presence of planned delivery time. Also in this work, we discuss the advantage of the use of the infinitesimal perturbation analysis method comparing to classical simulation methods.展开更多
The aim of this study is to determine the level to which the public is aware about ITS(intelligent transportation systems)technologies and how they perceive the potential advantages and inhibitors of ITS in Michigan.A...The aim of this study is to determine the level to which the public is aware about ITS(intelligent transportation systems)technologies and how they perceive the potential advantages and inhibitors of ITS in Michigan.A survey was performed with 200 participants living in Michigan,in urban,suburban and rural areas.Questions covered in the survey included how often and how bad traffic congestion occurred,how familiar travelers were with ITS technologies(adaptive traffic signals,real time monitoring of the traffic)and how much support travelers would provide for ITS initiatives.Results reveal that there is a high degree of traffic congestion awareness,there is low public awareness of ITS technologies.While respondents who were aware of ITS solutions had positive views about deploying them,especially in urban areas,they were less supportive of ITS solutions than they were among those who did not know much about these.Factors including area of residence,commute time and age were perceived to influence ITS along with more positive attitudes to ITS amongst urban dwellers and younger respondents.Analysis of key barriers to ITS implementation reflected high initial costs,challenges with technical integration and users’concerns surrounding privacy.展开更多
A methodology has been previously developed to provide the required data for the iRAP Star Rating 7 model using data sourced from MRWA database information(corporate inventory)and road 8 condition information suppleme...A methodology has been previously developed to provide the required data for the iRAP Star Rating 7 model using data sourced from MRWA database information(corporate inventory)and road 8 condition information supplemented by other data sources.This is referred to as MRWA RAP to 9 distinguish from data collected in accordance with iRAP protocols which provides data for AusRAP.10 The iRAP data is used by the Australian National Risk Assessment Model(ANRAM).This paper 11 describes the work done on updating MRWA RAP as well as the application of the ANRAM model 12 to assess proposed treatments on the Great Eastern Highway to improve road safety.展开更多
Indonesia as the largest archipelagic country has potential market for freight transport.Unfortunately according to Logistics Performance Index(LPI)by the World Bank in 2012,Indonesia National Logistics System perform...Indonesia as the largest archipelagic country has potential market for freight transport.Unfortunately according to Logistics Performance Index(LPI)by the World Bank in 2012,Indonesia National Logistics System performance still have not optimal.Congestion become one of problem issue which caused the cost of logistics in Indonesia is more expensive for the similar routes in other Asia country.Besides,the use of road transport for freight is still dominating in Indonesia.In order to accelerate the Indonesia economy development and solve out the transport modal split issue,the government has declared the Master Plan for the Acceleration and Expansion of Indonesian Economic Development(MP3EI).In which through this policy the government is trying to improve and develop all the infrastructure of the transport sector including multimodal transport and greenhouse gas emissions(GHG)reduction.This paper tries to give explanation toward logistics transport and its problem,current condition on freight transport and the government policies in Indonesia.The method is usingdescriptive analyse with qualitative data and interview method to gain the detail information from the stakeholder.展开更多
The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this laye...The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the averageseasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weathersituation, Barber＇s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessmentof improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber （particlesize 0.2-4 mm） by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mixdesign compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials withattention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirecttensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complexmodulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained andthe comparison with a conventional HMA （hot mix asphalt） show that these dry rubber bituminous mixtures are particularly effective indamping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has beenachieved for the assessment of its behavior in sub-ballast/base layers.展开更多
Recently aviation accident data shows that many fatal accidents in aviation are due to airworthiness issues despite the fact that all civil and private aircraft are required to comply with the airworthiness standards ...Recently aviation accident data shows that many fatal accidents in aviation are due to airworthiness issues despite the fact that all civil and private aircraft are required to comply with the airworthiness standards set by their national airworthiness authority.This paper presents a unique approach to continuous airworthiness problems optimization needed to reduce the risk associated by the gap between aircraft designers&manufacturing organization and continuing airworthiness(state of civil aviation authority and air operators).As a result of the paper summaries these problems and searching of the possible solutions to optimized,these problems are achieved to get more integration between(designers&manufacturing and air operators),finally there is recommendations are drawn to address the safe operation of the aircraft and can be given to the International Civil Aviation Organization(ICAO),Federal Aviation Administration(FAA)and European Aviation Safety Agency(EASA)and Civil Aviation Authorities(CAAs)for more integrate between all of them structure.展开更多
In many countries, traffic volumes and the number of drivers are rising faster than the availability of police officers whose routine duties include traffic law enforcement. Automated traffic enforcement, which produc...In many countries, traffic volumes and the number of drivers are rising faster than the availability of police officers whose routine duties include traffic law enforcement. Automated traffic enforcement, which produces photographic evidence of vehicles detected speeding or running red lights, can be used to supplement traditional enforcement. In the United States and Canada, a number of individuals and organizations have been very vocal in their opposition to automated traffic enforcement. They argue that automated enforcement programs are unnecessary for improving road safety, that they unfairly target relatively good drivers, and that they are motivated by revenue generation rather than safety. These arguments, however, often ignore the numerous peer-reviewed studies that have found real-world benefits in communities that use automated enforcement---cameras deter would-be violators, reduce crashes, and save lives. Solid, published research by a number of experts demonstrates that red light cameras save lives, and speed cameras substantially reduce speeding and speed-related crashes. Surveys of drivers and other road users indicate widespread support for automated enforcement. With regard to fairness, the objective of photo enforcement is to deter violations, not to surreptitiously catch violators. The more public the enforcement is, the better. If anything, automated enforcement programs improve fairness by reducing the potential for prejudicial enforcement. Finally, photo enforcement is intended to improve traffic safety by modifying the driver behaviors that lead to crashes, and it is reasonable to expect that people who break the law should pay for enforcing it. Ticket revenue should decline overtime as the cameras succeed in deterring would-be speeders and red light runners. This paper provides research-based responses to the critics＇ arguments as well as best practice guidelines for effective automated enforcement programs.展开更多
This paper presents the ZINDOT model,a methodology utilizing a zero-inflated negative binomial model with the variables used in the United States Department of Transportation(USDOT)accident prediction formula,to deter...This paper presents the ZINDOT model,a methodology utilizing a zero-inflated negative binomial model with the variables used in the United States Department of Transportation(USDOT)accident prediction formula,to determine the expected accident count at a highway-rail grade crossing.The model developed contains separate formulas to estimate the crash prediction value depending on the warning device type installed at the crossing:crossings with gates,crossings with flashing lights and no gates,and crossings with crossbucks.The proposed methodology also accounts for the observed accident count at a crossing using the Empirical Bayes method.The ZINDOT model estimates were compared to the USDOT model estimates to rank the crossings based on the expected accident frequency.It is observed that the new model can identify crossings with a greater number of accidents with Gates and Flashing Lights and Crossbucks in both Illinois(data which were used to develop the model)and Texas(data which were used to validate the model).A practitioner already using the USDOT formulae to estimate expected accident count at a crossing could easily use the ZINDOT model as it employs the same variables used in the USDOT formula.This methodology could be used to rank highway-rail grade crossings for resource allocation and safety improvement.展开更多
Two of the main reasons of traffic congestion in Lebanon are the high number of private vehicles and the absence of a decent public transportation system. While the problem regarding the unavailability of the public t...Two of the main reasons of traffic congestion in Lebanon are the high number of private vehicles and the absence of a decent public transportation system. While the problem regarding the unavailability of the public transportation system can be related to the government, the high number of private cars can be explained and tackled from different angles. This study aims to present a full bus system analysis and design as a solution for various problems regarding the transportation sector. Around 1,000 people completed a survey asking about the existing buses, and their willingness to use a decent bus system; results showed that 73% of the voters would take this advanced bus system. That means a reduction of 525 cars/hour after providing seven buses on the Kousba-Chekka roadway. This amount of cars replaced by buses also implied a decrease of noise pollution by 2 dB, and a significant decrease of accidents. It is concluded that a reliable bus system should be implemented.展开更多
Level crossing rails are high risk areas due to the combination of the limited effectiveness of current inspection methods and high corrosion rates which often exist.This paper discusses the current UK standard practi...Level crossing rails are high risk areas due to the combination of the limited effectiveness of current inspection methods and high corrosion rates which often exist.This paper discusses the current UK standard practices for the periodic inspection of level crossing rails using visual(VT)and conventional ultrasonic(UT)methods.The limitations of these methods are discussed and how these limitations affect the overall maintenance program for level crossings.A new inspection method,guided wave testing(GWT)is then described with particular emphasis on its advantages for inspecting level crossings.Finally,a review is given of the current Network Rail trial of GWT on level crossings using the G-Scan system,with representative results which demonstrate the effectiveness of GWT for this application.展开更多
Based on real jobs, this study was carried out the railway maintenance works in Taiwan. It hopes to use GIS （geographic information system） and BIM （building information modeling） for changing the maintenance mode...Based on real jobs, this study was carried out the railway maintenance works in Taiwan. It hopes to use GIS （geographic information system） and BIM （building information modeling） for changing the maintenance model from ＂post-damage repair＂ to ＂preventive maintenance＂ accordingly, this research will build a railway repairing database that installs all repair data. This database will also connect to GIS so that can be the source of analysis and statistic for repair paln. The main results of research are as follows： （l） all data stored on cloud space that raises the ability to manage and plan on repair; （2） simplify the file work and increase the quantity of case data to the manager who can get more reliable source; （3） the data offer objective judgment to avoid subjective argument. The GIS information can be added to improve the maintenance because of good analysis.展开更多
This paper describes the research of rollovers of passenger cars and proposes a ramp type test as a typical dynamic rollover test with evaluations of occupant injuries and vehicle deformation in accordance with variou...This paper describes the research of rollovers of passenger cars and proposes a ramp type test as a typical dynamic rollover test with evaluations of occupant injuries and vehicle deformation in accordance with various parametric functions. Many types of rollover tests have been conducted in the past and they have their merits and demerits. However, the ramp rollover test has a characteristic to evaluate both dummy injuries and vehicle deformations, and to perform tests under many conditions by exchanging ramp dimensions, steer timings made rotation and velocity of the vehicle.展开更多
In the recent years,TNCs(transportation network companies)and on-demand ridesharing services have grown rapidly.Given conflicting reports on TNC impacts,a need exists to study mode choice shifts in the presence of TNC...In the recent years,TNCs(transportation network companies)and on-demand ridesharing services have grown rapidly.Given conflicting reports on TNC impacts,a need exists to study mode choice shifts in the presence of TNC services and their effects on urban congestion.Using Birmingham,AL(Alabama)as a case study,this paper showcases the feasibility of modeling TNC services using the MATSim(Multi-Agent Transport Simulation)platform,and evaluating the impact of such services on traffic operations.Data used for the study were gathered from Uber drivers and riders through surveys,as well as the US Census.The results indicate that when 200,400,and 800 TNC vehicles are added to the network,the VKT(vehicle kilometers traveled)increase by 22%,23.6%,and 23.2%,respectively,compared to the baseline scenario(no TNC service).Analysis of hourly average speeds,hourly average travel times,and hourly volumes along study corridors further indicate that TNC services increase traffic congestion,in particular,during the AM/PM peak periods.Moreover,the study shows that the optimal TNC fleet size for the Birmingham region is 400 to 500 active TNC vehicles per day.Such fleet size minimizes idle time and the number of TNC vehicles hovering,which have adverse impacts on TNC drivers,and the environment while ensuring TNC service availability and reasonable waiting times for TNC customers.展开更多
After a cycle of management that began with President Luis Inácio Lula da Silva,the inauguration of Jair Bolsonaro bringing a new period of management in the Federative Republic of Brazil.In addition to macroecon...After a cycle of management that began with President Luis Inácio Lula da Silva,the inauguration of Jair Bolsonaro bringing a new period of management in the Federative Republic of Brazil.In addition to macroeconomic issues and various other national interests,the new government will have to analyze the legacies and will have new challenges in the civil aviation sector.Using an evolutionary historical perspective,this article briefly points out some alternatives for the implementation of viable projects for the development of this important sector for the country’s development.展开更多
As part of improving services done for various clients in all Moroccan areas, Moroccan exportation group of fruits and vegetables in collaboration with their packaging units and producers, tends to cooperate in order ...As part of improving services done for various clients in all Moroccan areas, Moroccan exportation group of fruits and vegetables in collaboration with their packaging units and producers, tends to cooperate in order to face with international competitiveness. Indeed, the complexity of networks of partners has led policy-makers to implement new techniques and tools to help control different processes. For this reason, the implementation of a permanent monitoring of different operations ranging from production, packaging, and distribution of perishable products has become paramount. This article aims to propose a model of multi-agent citrus supply chain, based on indicators for monitoring and evaluation of performance of its logistics systems, in order to build a new independent, robust and responsive chain, and to optimize and control the flow of materials and information between the different actors and stakeholders of the chain.展开更多
By coordination and cooperation between multi-agents, this paper proposes the network of intelligent agents which can reduce the search time needed to finding a parking place. Based on multi-agent model, the fined sol...By coordination and cooperation between multi-agents, this paper proposes the network of intelligent agents which can reduce the search time needed to finding a parking place. Based on multi-agent model, the fined solution is designed to help drivers in finding a parking space at anytime and anywhere. Three services are offered: the search for a vacant place, directions to a parking space and booking a place for parking. The results of this study generated by the platform MATSim transport simulation, show that our approach optimizes the operation of vehicles in a parking need with the aim of reducing congestion, and improve traffic flow in urban area. A comparison between the first method where the vehicles are random and the second method where vehicles are steered to vacant parking spaces shows that the minimization of time looking for a parking space could improve circulation by reducing the number of cars in the morning of 2% and 0.7% of the evening. In addition, the traffic per hour per day was reduced by approximately 4.17%.展开更多
Smart mobility, seen as car based solutions with greater fuel efficiency and shifts to cars that are essentially informationtechnology-products, is sometimes presented as the way forward for car mobility. This article...Smart mobility, seen as car based solutions with greater fuel efficiency and shifts to cars that are essentially informationtechnology-products, is sometimes presented as the way forward for car mobility. This article presents developments, visions andscenarios for a debate on the role and the frame of smart mobility in the future of car mobility. Sustainability and life style issues areintroduced as important backgrounds. As for a majority of households smart mobility solutions are important, it can be concludedthat an important minority of households is searchin~ for other solutions than technological framed smart展开更多
Railways are very important to our society due to their efficiency and reduced environmental effects.A system for the measurement of the condition of the formation on which a permanent way(pairs of rails laid on sleep...Railways are very important to our society due to their efficiency and reduced environmental effects.A system for the measurement of the condition of the formation on which a permanent way(pairs of rails laid on sleepers)is located is investigated in this work.This will allow effective asset management and reduce the costs of rail maintenance.Areas where the formation is either weak or changes rapidly present problems when maintaining a section of the track due to poor track geometry.Formation stiffness is a difficult parameter to measure and requires extensive research efforts.In this work a train-track interaction problem is investigated with a quarter train track model,which consists of a coach,bogie and wheel.The train-irregularity model is developed which computes the train response to irregularities,such as the deflection by stiffness changes.Using this train–irregularity model,the effects of train speed on the wheel/rail interaction force over the stiffness changes are studied and the track stiffness is also analysed,which will be used in future analysis to calculate the actual stiffness of the track when using laser measurement techniques.展开更多
文摘The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt.A high-level model was developed to predict vehicle fuel and electricity consumption based on driving characteristics and vehicle state inputs.These techniques were leveraged to optimize energy efficiency via green routing and intelligent control mode scheduling,which were evaluated using prospective driving routes between tens of thousands of real-world origin/destination pairs.The overall energy savings potential of green routing and intelligent mode scheduling was estimated at 5%and 3%,respectively.These represent substantial opportunities considering that they only require software adjustments to implement.
文摘Continuous vehicle tracking as well as monitoring driving behaviour, is significant services that are needed by manyindustries including insurance and vehicle rental companies. The main goal of this paper is to provide methods to model the quality ofthe driving behaviour based on FIS （fuzzy inference systems）. The models consider vehicle dynamics as long as the human behaviourparameters, expressed by a set of raw measurements which are obtained from various environmental sensors. In addition,assessment-driving behaviour model is simulated and tested by two different FISs： Mamdani and Sugeno-TSK. The simulation resultsillustrate the critical distinctions between the two FISs using the proposed driving behaviour models. These differences are based onvarious processing times, robust behaviour of the FISs, outputs MFs （membership functions）, fuzzification-techniques, flexibility inthe systems design and computational efficiency.
文摘In this paper, a manufacturing supply chain system composed by a single-product machine, a buffer and a stochastic demand is considered. A stochastic fluid model is adopted to describe the system and to take into account stochastic delivery times. The objective of this paper is to evaluate the optimal buffer level used in hedging point policy taken into account planned delivery times, machine failures and random demands. This optimal buffer allows minimizing the sum of inventory, transportation, lost sales and late delivery costs. Infinitesimal perturbation analysis method is used for optimizing the proposed system. Using the stochastic fluid model, the trajectories of buffer level are studied and the infinitesimal perturbation analysis estimators are evaluated. These estimators are shown to be unbiased and then they are implanted in an optimization algorithm, which determines the optimal buffer level in the presence of planned delivery time. Also in this work, we discuss the advantage of the use of the infinitesimal perturbation analysis method comparing to classical simulation methods.
文摘The aim of this study is to determine the level to which the public is aware about ITS(intelligent transportation systems)technologies and how they perceive the potential advantages and inhibitors of ITS in Michigan.A survey was performed with 200 participants living in Michigan,in urban,suburban and rural areas.Questions covered in the survey included how often and how bad traffic congestion occurred,how familiar travelers were with ITS technologies(adaptive traffic signals,real time monitoring of the traffic)and how much support travelers would provide for ITS initiatives.Results reveal that there is a high degree of traffic congestion awareness,there is low public awareness of ITS technologies.While respondents who were aware of ITS solutions had positive views about deploying them,especially in urban areas,they were less supportive of ITS solutions than they were among those who did not know much about these.Factors including area of residence,commute time and age were perceived to influence ITS along with more positive attitudes to ITS amongst urban dwellers and younger respondents.Analysis of key barriers to ITS implementation reflected high initial costs,challenges with technical integration and users’concerns surrounding privacy.
文摘A methodology has been previously developed to provide the required data for the iRAP Star Rating 7 model using data sourced from MRWA database information(corporate inventory)and road 8 condition information supplemented by other data sources.This is referred to as MRWA RAP to 9 distinguish from data collected in accordance with iRAP protocols which provides data for AusRAP.10 The iRAP data is used by the Australian National Risk Assessment Model(ANRAM).This paper 11 describes the work done on updating MRWA RAP as well as the application of the ANRAM model 12 to assess proposed treatments on the Great Eastern Highway to improve road safety.
文摘Indonesia as the largest archipelagic country has potential market for freight transport.Unfortunately according to Logistics Performance Index(LPI)by the World Bank in 2012,Indonesia National Logistics System performance still have not optimal.Congestion become one of problem issue which caused the cost of logistics in Indonesia is more expensive for the similar routes in other Asia country.Besides,the use of road transport for freight is still dominating in Indonesia.In order to accelerate the Indonesia economy development and solve out the transport modal split issue,the government has declared the Master Plan for the Acceleration and Expansion of Indonesian Economic Development(MP3EI).In which through this policy the government is trying to improve and develop all the infrastructure of the transport sector including multimodal transport and greenhouse gas emissions(GHG)reduction.This paper tries to give explanation toward logistics transport and its problem,current condition on freight transport and the government policies in Indonesia.The method is usingdescriptive analyse with qualitative data and interview method to gain the detail information from the stakeholder.
文摘The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the averageseasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weathersituation, Barber＇s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessmentof improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber （particlesize 0.2-4 mm） by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mixdesign compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials withattention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirecttensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complexmodulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained andthe comparison with a conventional HMA （hot mix asphalt） show that these dry rubber bituminous mixtures are particularly effective indamping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has beenachieved for the assessment of its behavior in sub-ballast/base layers.
文摘Recently aviation accident data shows that many fatal accidents in aviation are due to airworthiness issues despite the fact that all civil and private aircraft are required to comply with the airworthiness standards set by their national airworthiness authority.This paper presents a unique approach to continuous airworthiness problems optimization needed to reduce the risk associated by the gap between aircraft designers&manufacturing organization and continuing airworthiness(state of civil aviation authority and air operators).As a result of the paper summaries these problems and searching of the possible solutions to optimized,these problems are achieved to get more integration between(designers&manufacturing and air operators),finally there is recommendations are drawn to address the safe operation of the aircraft and can be given to the International Civil Aviation Organization(ICAO),Federal Aviation Administration(FAA)and European Aviation Safety Agency(EASA)and Civil Aviation Authorities(CAAs)for more integrate between all of them structure.
文摘In many countries, traffic volumes and the number of drivers are rising faster than the availability of police officers whose routine duties include traffic law enforcement. Automated traffic enforcement, which produces photographic evidence of vehicles detected speeding or running red lights, can be used to supplement traditional enforcement. In the United States and Canada, a number of individuals and organizations have been very vocal in their opposition to automated traffic enforcement. They argue that automated enforcement programs are unnecessary for improving road safety, that they unfairly target relatively good drivers, and that they are motivated by revenue generation rather than safety. These arguments, however, often ignore the numerous peer-reviewed studies that have found real-world benefits in communities that use automated enforcement---cameras deter would-be violators, reduce crashes, and save lives. Solid, published research by a number of experts demonstrates that red light cameras save lives, and speed cameras substantially reduce speeding and speed-related crashes. Surveys of drivers and other road users indicate widespread support for automated enforcement. With regard to fairness, the objective of photo enforcement is to deter violations, not to surreptitiously catch violators. The more public the enforcement is, the better. If anything, automated enforcement programs improve fairness by reducing the potential for prejudicial enforcement. Finally, photo enforcement is intended to improve traffic safety by modifying the driver behaviors that lead to crashes, and it is reasonable to expect that people who break the law should pay for enforcing it. Ticket revenue should decline overtime as the cameras succeed in deterring would-be speeders and red light runners. This paper provides research-based responses to the critics＇ arguments as well as best practice guidelines for effective automated enforcement programs.
文摘This paper presents the ZINDOT model,a methodology utilizing a zero-inflated negative binomial model with the variables used in the United States Department of Transportation(USDOT)accident prediction formula,to determine the expected accident count at a highway-rail grade crossing.The model developed contains separate formulas to estimate the crash prediction value depending on the warning device type installed at the crossing:crossings with gates,crossings with flashing lights and no gates,and crossings with crossbucks.The proposed methodology also accounts for the observed accident count at a crossing using the Empirical Bayes method.The ZINDOT model estimates were compared to the USDOT model estimates to rank the crossings based on the expected accident frequency.It is observed that the new model can identify crossings with a greater number of accidents with Gates and Flashing Lights and Crossbucks in both Illinois(data which were used to develop the model)and Texas(data which were used to validate the model).A practitioner already using the USDOT formulae to estimate expected accident count at a crossing could easily use the ZINDOT model as it employs the same variables used in the USDOT formula.This methodology could be used to rank highway-rail grade crossings for resource allocation and safety improvement.
文摘Two of the main reasons of traffic congestion in Lebanon are the high number of private vehicles and the absence of a decent public transportation system. While the problem regarding the unavailability of the public transportation system can be related to the government, the high number of private cars can be explained and tackled from different angles. This study aims to present a full bus system analysis and design as a solution for various problems regarding the transportation sector. Around 1,000 people completed a survey asking about the existing buses, and their willingness to use a decent bus system; results showed that 73% of the voters would take this advanced bus system. That means a reduction of 525 cars/hour after providing seven buses on the Kousba-Chekka roadway. This amount of cars replaced by buses also implied a decrease of noise pollution by 2 dB, and a significant decrease of accidents. It is concluded that a reliable bus system should be implemented.
文摘Level crossing rails are high risk areas due to the combination of the limited effectiveness of current inspection methods and high corrosion rates which often exist.This paper discusses the current UK standard practices for the periodic inspection of level crossing rails using visual(VT)and conventional ultrasonic(UT)methods.The limitations of these methods are discussed and how these limitations affect the overall maintenance program for level crossings.A new inspection method,guided wave testing(GWT)is then described with particular emphasis on its advantages for inspecting level crossings.Finally,a review is given of the current Network Rail trial of GWT on level crossings using the G-Scan system,with representative results which demonstrate the effectiveness of GWT for this application.
文摘Based on real jobs, this study was carried out the railway maintenance works in Taiwan. It hopes to use GIS （geographic information system） and BIM （building information modeling） for changing the maintenance model from ＂post-damage repair＂ to ＂preventive maintenance＂ accordingly, this research will build a railway repairing database that installs all repair data. This database will also connect to GIS so that can be the source of analysis and statistic for repair paln. The main results of research are as follows： （l） all data stored on cloud space that raises the ability to manage and plan on repair; （2） simplify the file work and increase the quantity of case data to the manager who can get more reliable source; （3） the data offer objective judgment to avoid subjective argument. The GIS information can be added to improve the maintenance because of good analysis.
文摘This paper describes the research of rollovers of passenger cars and proposes a ramp type test as a typical dynamic rollover test with evaluations of occupant injuries and vehicle deformation in accordance with various parametric functions. Many types of rollover tests have been conducted in the past and they have their merits and demerits. However, the ramp rollover test has a characteristic to evaluate both dummy injuries and vehicle deformations, and to perform tests under many conditions by exchanging ramp dimensions, steer timings made rotation and velocity of the vehicle.
基金the US DOT through the STRIDE University Transportation Center.
文摘In the recent years,TNCs(transportation network companies)and on-demand ridesharing services have grown rapidly.Given conflicting reports on TNC impacts,a need exists to study mode choice shifts in the presence of TNC services and their effects on urban congestion.Using Birmingham,AL(Alabama)as a case study,this paper showcases the feasibility of modeling TNC services using the MATSim(Multi-Agent Transport Simulation)platform,and evaluating the impact of such services on traffic operations.Data used for the study were gathered from Uber drivers and riders through surveys,as well as the US Census.The results indicate that when 200,400,and 800 TNC vehicles are added to the network,the VKT(vehicle kilometers traveled)increase by 22%,23.6%,and 23.2%,respectively,compared to the baseline scenario(no TNC service).Analysis of hourly average speeds,hourly average travel times,and hourly volumes along study corridors further indicate that TNC services increase traffic congestion,in particular,during the AM/PM peak periods.Moreover,the study shows that the optimal TNC fleet size for the Birmingham region is 400 to 500 active TNC vehicles per day.Such fleet size minimizes idle time and the number of TNC vehicles hovering,which have adverse impacts on TNC drivers,and the environment while ensuring TNC service availability and reasonable waiting times for TNC customers.
文摘After a cycle of management that began with President Luis Inácio Lula da Silva,the inauguration of Jair Bolsonaro bringing a new period of management in the Federative Republic of Brazil.In addition to macroeconomic issues and various other national interests,the new government will have to analyze the legacies and will have new challenges in the civil aviation sector.Using an evolutionary historical perspective,this article briefly points out some alternatives for the implementation of viable projects for the development of this important sector for the country’s development.
文摘As part of improving services done for various clients in all Moroccan areas, Moroccan exportation group of fruits and vegetables in collaboration with their packaging units and producers, tends to cooperate in order to face with international competitiveness. Indeed, the complexity of networks of partners has led policy-makers to implement new techniques and tools to help control different processes. For this reason, the implementation of a permanent monitoring of different operations ranging from production, packaging, and distribution of perishable products has become paramount. This article aims to propose a model of multi-agent citrus supply chain, based on indicators for monitoring and evaluation of performance of its logistics systems, in order to build a new independent, robust and responsive chain, and to optimize and control the flow of materials and information between the different actors and stakeholders of the chain.
文摘By coordination and cooperation between multi-agents, this paper proposes the network of intelligent agents which can reduce the search time needed to finding a parking place. Based on multi-agent model, the fined solution is designed to help drivers in finding a parking space at anytime and anywhere. Three services are offered: the search for a vacant place, directions to a parking space and booking a place for parking. The results of this study generated by the platform MATSim transport simulation, show that our approach optimizes the operation of vehicles in a parking need with the aim of reducing congestion, and improve traffic flow in urban area. A comparison between the first method where the vehicles are random and the second method where vehicles are steered to vacant parking spaces shows that the minimization of time looking for a parking space could improve circulation by reducing the number of cars in the morning of 2% and 0.7% of the evening. In addition, the traffic per hour per day was reduced by approximately 4.17%.
文摘Smart mobility, seen as car based solutions with greater fuel efficiency and shifts to cars that are essentially informationtechnology-products, is sometimes presented as the way forward for car mobility. This article presents developments, visions andscenarios for a debate on the role and the frame of smart mobility in the future of car mobility. Sustainability and life style issues areintroduced as important backgrounds. As for a majority of households smart mobility solutions are important, it can be concludedthat an important minority of households is searchin~ for other solutions than technological framed smart
文摘Railways are very important to our society due to their efficiency and reduced environmental effects.A system for the measurement of the condition of the formation on which a permanent way(pairs of rails laid on sleepers)is located is investigated in this work.This will allow effective asset management and reduce the costs of rail maintenance.Areas where the formation is either weak or changes rapidly present problems when maintaining a section of the track due to poor track geometry.Formation stiffness is a difficult parameter to measure and requires extensive research efforts.In this work a train-track interaction problem is investigated with a quarter train track model,which consists of a coach,bogie and wheel.The train-irregularity model is developed which computes the train response to irregularities,such as the deflection by stiffness changes.Using this train–irregularity model,the effects of train speed on the wheel/rail interaction force over the stiffness changes are studied and the track stiffness is also analysed,which will be used in future analysis to calculate the actual stiffness of the track when using laser measurement techniques.
