This paper has concluded six features that belong to passenger vehicle types based on genetic algorithm(GA)of feature selection.We have obtained an optimal feature subset,including length,ratio of width and length,and...This paper has concluded six features that belong to passenger vehicle types based on genetic algorithm(GA)of feature selection.We have obtained an optimal feature subset,including length,ratio of width and length,and ratio of height and length.And then we apply this optimal feature subset as well as another feature set,containing length,width and height,to the network input.Back-propagation(BP)neural network and support vector machine(SVM)are applied to classify the passenger vehicle type.There are four passenger vehicle types.This paper selects 400 samples of passenger vehicles,among which 320 samples are used as training set(each class has 80 samples)and the other 80 samples as testing set,taking the feature of the samples as network input and taking four passenger vehicle types as output.For the test,we have applied BP neural network to choose the optimal feature subset as network input,and the results show that the total classification accuracy rate can reach 96%,and the classification accuracy rate of first type can reach 100%.In this condition,we obtain a conclusion that this algorithm is better than the traditional ones[9].展开更多
The study estimated the cost of local and global air emissions, and to compare the differences between electric passenger vehicles (EV) and conventional, internal combustion engine (ICE) vehicles. The air emissions we...The study estimated the cost of local and global air emissions, and to compare the differences between electric passenger vehicles (EV) and conventional, internal combustion engine (ICE) vehicles. The air emissions were estimated for the year 2020, for Denmark, France and Israel, because of their significantly different fuel mixes to produce electricity—a high percentage of renewable energy, mainly nuclear energy and high fossil fuels, respectively. Air emissions from electricity production and conventional traffic were calculated for each country and then multiplied by the specific country’s cost of emissions. Subtracting the total cost of electricity production from the total cost of conventional transportation yields the total benefit for each of the economies studied. The environmental benefit, depending on EV penetration rates, was found to be in the range of 7.8 to 133 MEUR/year for Denmark, 94 to1948 MEUR/year for France and only 4 to 82 MEUR/year for Israel, whose energy mix is the most polluting. Our analysis also shows higher potential benefits when replacing passenger car fleets comprising a high percentage of diesel cars with EVs, as well as in highly populated areas. In addition, we quantified the differences between EVs with fixed batteries and the new switch able battery concept (EASYBAT), as part of the EU 7th Framework Program me. The additional electricity demands for the EASYBAT concept are negligible, and therefore, do not change the overall conclusion that the cleaner the electricity energy mix and the higher the penetration of EVs, the higher the environmental benefits achieved.展开更多
The highway capacity manual(HCM)provides a formula to calculate the heavy vehicle adjustment factor(fHV)as a function of passenger car equivalent factors for the heavy vehicle(ET).However,a significant drawback is tha...The highway capacity manual(HCM)provides a formula to calculate the heavy vehicle adjustment factor(fHV)as a function of passenger car equivalent factors for the heavy vehicle(ET).However,a significant drawback is that the methodology was established solely based on human-driven passenger cars(HDPC)and human-driven heavy vehicles(HDHV).Due to automated passenger cars(APCs),a new adjustment factor(fAV)might be expected.This study simulated traffic flows at different percentages of HDHVs and APCs to investigate the impacts of HDHVs and APCs on freeway capacity by analyzing their influence on fHV and fAV values.The simulation determined observed adjustment factors at different percentages of HDHVs and APCs(fobserved).The HCM formula was used to calculate(fHCM).Modifications to the HCM formula are proposed,and vehicle adjustment factors due to HDHVs and APCs were calculated(fproposed).Results showed that,in the presence of APCs,while fobserved and fHCM were statistically significantly different,fobserved and fproposed were statistically equal.Hence,this study recommends using the proposed formula when determining vehicle adjustment factors(fproposed)due to HDHVs and APCs in the traffic stream.展开更多
In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices...In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices were used, interaction of force among pedestrians or between pedestrians and constructions was considered, and static floor fields in a multi-level exit environment were simplified into cabin and exit static floor fields. Compared with the traditional cellular automata model, the multi-grid model enhanced the continuity of the passengers'track and the precision of the boundary qualifications. The functions of the dislocation distribution of passengers as well as partial overlap of tracks due to congestion were realized. Furthermore, taking the typical cabin environment as an example, the two models were used to analyze passenger evacuation under the same conditions. It was found that the laws of passenger evacuation simulated by the two models are similar, while the simulation's authenticity and accuracy are enhanced by the multi-grid model.展开更多
The launching and recovery process of a human-occupied vehicle(HOV)faces more complex wave effects than other types of submersible operations.However,due to the nonlinearity between the HOV and its mother ship,difficu...The launching and recovery process of a human-occupied vehicle(HOV)faces more complex wave effects than other types of submersible operations.However,due to the nonlinearity between the HOV and its mother ship,difficulties occur in theoretically simulating their coupled motion and hydrodynamics.The coupled motion responses and the load under different regular wave conditions are investigated experimentally in this study.The optimized design of the experimental scheme simulated the launching and recovery process of the mother ship and HOV in regular waves.The attitude sensor performed synchronous real-time measurement of the coupled motion between the mother ship and HOV as well as obtained the load data on the coupled motion under different cable lengths.The results show that models in heading waves mainly lead to the vertical motion of the hoisting point.In beam waves,the transverse and vertical motions of the hoisting point occur in a certain frequency of waves.Under the heading and beam wave conditions,the longer the hoisting cable is,the greater the movement amplitude of the submersible is.Moreover,compared with the condition of the beam waves,the hoisting submersible has less influence on the mother ship under the condition of the heading waves.The findings provide theoretical support for the design optimization of the launching and recovery operation.展开更多
The purpose of this paper is to introduce an innovative methodology in shipping investment evaluation based on simulation of a project cash flow. It concerns a complementary approach to current practices and its aim i...The purpose of this paper is to introduce an innovative methodology in shipping investment evaluation based on simulation of a project cash flow. It concerns a complementary approach to current practices and its aim is to provide more information mainly to ship-owners that consider the feasibility of deploying Ro-Ro Passenger ferries. The paper examines a typical semi-conventional RoPax ferry operating in the Aegean Sea. It addresses important economic, operational and procedural issues concerning risk evaluation. The current status is that risk is a notion still strange to main stakeholders. The Greek practice in performing a feasibility study for a project draws on investor's experience and feeling aided by a preliminary economic study. The main thesis of this paper is that there are alternative techniques to evaluate investment risk and measure profitability of a project. A Monte Carlo simulation in collaboration with a typical Ro-Ro cash-flow model is implemented to reveal the extent of risk and provide a useful tool for the assessment of future investments in Greek Short Sea Shipping.展开更多
The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that ope...The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.展开更多
Following developments in artificial intelligence and big data technology,the level of intelligence in intelligent vessels has been improved.Intelligent vessels are being developed into unmanned surface vehicles(USVs)...Following developments in artificial intelligence and big data technology,the level of intelligence in intelligent vessels has been improved.Intelligent vessels are being developed into unmanned surface vehicles(USVs),which have widely interested scholars in the shipping industry due to their safety,high efficiency,and energy-saving qualities.Considering the current development of USVs,the types of USVs and applications domestically and internationally are being investigated.USVs emerged with technological developments and their characteristics show some differences from traditional vessels,which brings some problems and advantages for their application.Certain maritime regulations are not applicable to USVs and must be changed.The key technologies in the current development of USVs are being investigated.While the level of intelligence is improving,the protection of cargo cannot be neglected.An innovative approach to the internal structure of USVs is proposed,where the inner hull can automatically recover its original state in case of outer hull tilting.Finally,we summarize the development status of USVs,which are an inevitable direction of development in the marine field.展开更多
Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equ...Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equivalent barrier has not previously been proven to meet the requirements of containing the vehicle and dissipating sufficient impact energy for passenger protection. As full-scale crash testing is very expensive, the number of data that can be measured in a test is usually limited, and it may not always be possible to obtain good quality measurements in such a test, a reliable and efficient numerical simulation of crash testing is therefore very useful. This paper presents finite element simulations of a 3-rail steel road traffic barrier under vehicle impact. The performance levels defined in Australian Standards AS5100 Clause 10.5 for these barriers are checked. The numerical simulations show that the barrier is able to meet low performance levels. However, the maximum deceleration is higher than the acceptable limit for passenger protection. If present, a kerb launches the vehicles into the barrier, allowing for the possibility of overriding the barrier under certain circumstances, but it redirects the vehicle and reduces the incident angle, which reduces impact force on the barrier. Further investigation into all common kerb profiles on roads should be carried out, as only one kerb profile is investigated in this study.展开更多
For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of...For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of this choice resides in the opportunity to reduce weight and dimension, in comparison to a traditional In- ternal Combustion Engine (ICE). It’s not possible to use the GT engine directly for the vehicle traction, so the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is pure electric. Many efforts are spent in the definition of a generic scientific method to define the correct ratio HD (the Hybridization Degree) between the installed power of the battery pack and that of the GT electric generator which simultaneously guarantee the main life for the battery package and the ca- pacity of the vehicle to complete a common mission (about 15 km - 30 km) without lack of energy or stop. This paper reports all studies carried out and finally proposes a possible configuration (weight distribution, VMU logic control, GT dimensions and power rate, battery package characteristics and so on) for mid term solution in the Italian transport system.展开更多
In this study, the influences of accumulated mileage (deterioration) and technological changes (emission standards) on emission factors (EFs) of regulated pollutants (CO, HC, and NOx) from gasoline passenger v...In this study, the influences of accumulated mileage (deterioration) and technological changes (emission standards) on emission factors (EFs) of regulated pollutants (CO, HC, and NOx) from gasoline passenger vehicles were investigated based on Inspection and Maintenance (I/M) data using the chassis dynamometer method. The accumulated mileage of passenger vehicles was significantly linearly correlated with vehicle age. For most cases, the average EFs of CO, HC and NOx were significantly linearly correlated with accumulated mileage, indicating that emission deterioration had a significant impact on pollutant EFs. Implemented emission standards markedly influenced the EFs of regulated pollutants, and EFs markedly decreased with progressing emission standards. The present study also compared EFs of regulated pollutants between this study and the International vehicle emission (IVE) model, and marked differences in EFs were seen with variations in emission standards, vehicle types and accumulated mileage; NOx EFs in this study were higher than in the IVE model. The results provide new insight into estimating regulated pollutant emissions using the IVE model.展开更多
An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily b...An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily by a portable emission measurement system.The on-board diagnostic(OBD)approach,which is flexible and offers high-resolution data collection,is a promising fuel consumption monitoring method.Three LDPVs were tested with a laboratory dynamometer based on a type-approval cycle,the New European Driving Cycle(NEDC).Fuel consumption was measured by the OBD and constant-volume sampling system(CVS,a regulatory method)to verify the accuracy of the OBD values.The results of the OBD method and the regulatory carbon balance method exhibited a strong linear correlation(e.g.,R^2=0.906-0.977).Compared with the carbon balance results,the fuel consumption results using the OBD were 7.1%±4.3%lower on average.Furthermore,the real-world fuel consumption of six LDPVs was tested in Beijing using the OBD.The results showed that the normalized NEDC real-world fliel consumption of the tested vehicles was 13%±17%higher than the type-approval-based fuel consumption.Because the OBD values are lower than the actual fuel consumption,using a carbon balance method may result in a larger discrepancy between real-word and type-approval ftiel consumption.By means of the operating mode binning and micro trip methods,a strong relationship(R^2=0.984)was established between the average speed and relative fuel consumption.For congested roads(average vehicle speed less than 25 km/h),the fuel consumption of LDPVs is highly sensitive to changes in average speed.展开更多
The problems associated with evacuation of people from the ship in an emergency situation are analyzed, especially passenger ships are taken under consideration. The most dangerous accidents requiring evacuation are d...The problems associated with evacuation of people from the ship in an emergency situation are analyzed, especially passenger ships are taken under consideration. The most dangerous accidents requiring evacuation are described. Marine accidents often occur as eliminating all of the hazards to human health and life is still impossible. In every case, the evacuation process from the ship must be taken under consideration. Evacuation route arrangement should provide the possibility of safe departure from danger areas for passengers and crew members. Evacuation routes designed for human interaction within the evacuation process and other important factors are reviewed. Additionally, the method for seeking evacuation time as a function of initial distribution of passengers and evacuation routes choosing is suggested. A genetic algorithm will be used, whilst the calculated evacuation time is connected with a fitness function. Parameters Of evacuation routes topology are coded as non-binary chromosomes. Genetic operators are fitted for such types of problems to avoid receiving infeasible solutions. The objective of the proposed method is to find the evacuation time in worse case scenarios.展开更多
On July 24,2012,the State Council of the People’s Republic of China implemented'a toll-free program for small passenger vehicles during major vacations1).In the several months that followed,local governments issu...On July 24,2012,the State Council of the People’s Republic of China implemented'a toll-free program for small passenger vehicles during major vacations1).In the several months that followed,local governments issued implementation articles.The current Major Vacation Tollfree Program for small passenger vehicles(MVTP)pioneers the concept(Xu and Gao,2016),'Benefaction to People.'The current MVTP has received展开更多
Passenger vehicles (including vans) registrations year-on-year increased 42.2% in Feb. 2007, reaching 408,570 units. Due to the reason there was a larger sales period before the past Chinese New Year in late of Februa...Passenger vehicles (including vans) registrations year-on-year increased 42.2% in Feb. 2007, reaching 408,570 units. Due to the reason there was a larger sales period before the past Chinese New Year in late of February, thus Feb. 2007 made a rather different tendency than previous years. The registrations exceeded more than 0.2 million compared with the展开更多
1. An overall judgment on the situation 2006 saw the rapid growth of passenger vehicles, with the production capacity putting into use rose from less than 70 percent to around 80 percent. That with light commercial ve...1. An overall judgment on the situation 2006 saw the rapid growth of passenger vehicles, with the production capacity putting into use rose from less than 70 percent to around 80 percent. That with light commercial vehicles was similar too. The situation in 2005 and 2006 showed that there are no evidential overdone production capacity.展开更多
基金China Postdoctoral Science Foundation(No.20100481307)Natural Science Foundation of Shanxi(No.2009011018-3)
文摘This paper has concluded six features that belong to passenger vehicle types based on genetic algorithm(GA)of feature selection.We have obtained an optimal feature subset,including length,ratio of width and length,and ratio of height and length.And then we apply this optimal feature subset as well as another feature set,containing length,width and height,to the network input.Back-propagation(BP)neural network and support vector machine(SVM)are applied to classify the passenger vehicle type.There are four passenger vehicle types.This paper selects 400 samples of passenger vehicles,among which 320 samples are used as training set(each class has 80 samples)and the other 80 samples as testing set,taking the feature of the samples as network input and taking four passenger vehicle types as output.For the test,we have applied BP neural network to choose the optimal feature subset as network input,and the results show that the total classification accuracy rate can reach 96%,and the classification accuracy rate of first type can reach 100%.In this condition,we obtain a conclusion that this algorithm is better than the traditional ones[9].
文摘The study estimated the cost of local and global air emissions, and to compare the differences between electric passenger vehicles (EV) and conventional, internal combustion engine (ICE) vehicles. The air emissions were estimated for the year 2020, for Denmark, France and Israel, because of their significantly different fuel mixes to produce electricity—a high percentage of renewable energy, mainly nuclear energy and high fossil fuels, respectively. Air emissions from electricity production and conventional traffic were calculated for each country and then multiplied by the specific country’s cost of emissions. Subtracting the total cost of electricity production from the total cost of conventional transportation yields the total benefit for each of the economies studied. The environmental benefit, depending on EV penetration rates, was found to be in the range of 7.8 to 133 MEUR/year for Denmark, 94 to1948 MEUR/year for France and only 4 to 82 MEUR/year for Israel, whose energy mix is the most polluting. Our analysis also shows higher potential benefits when replacing passenger car fleets comprising a high percentage of diesel cars with EVs, as well as in highly populated areas. In addition, we quantified the differences between EVs with fixed batteries and the new switch able battery concept (EASYBAT), as part of the EU 7th Framework Program me. The additional electricity demands for the EASYBAT concept are negligible, and therefore, do not change the overall conclusion that the cleaner the electricity energy mix and the higher the penetration of EVs, the higher the environmental benefits achieved.
文摘The highway capacity manual(HCM)provides a formula to calculate the heavy vehicle adjustment factor(fHV)as a function of passenger car equivalent factors for the heavy vehicle(ET).However,a significant drawback is that the methodology was established solely based on human-driven passenger cars(HDPC)and human-driven heavy vehicles(HDHV).Due to automated passenger cars(APCs),a new adjustment factor(fAV)might be expected.This study simulated traffic flows at different percentages of HDHVs and APCs to investigate the impacts of HDHVs and APCs on freeway capacity by analyzing their influence on fHV and fAV values.The simulation determined observed adjustment factors at different percentages of HDHVs and APCs(fobserved).The HCM formula was used to calculate(fHCM).Modifications to the HCM formula are proposed,and vehicle adjustment factors due to HDHVs and APCs were calculated(fproposed).Results showed that,in the presence of APCs,while fobserved and fHCM were statistically significantly different,fobserved and fproposed were statistically equal.Hence,this study recommends using the proposed formula when determining vehicle adjustment factors(fproposed)due to HDHVs and APCs in the traffic stream.
基金Supported by the Ph.D Programs Foundation of Ministryof Education of China under Grant No.201023041108the Fundamental Research Funds for the Central Universities under Grant No.61004008
文摘In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices were used, interaction of force among pedestrians or between pedestrians and constructions was considered, and static floor fields in a multi-level exit environment were simplified into cabin and exit static floor fields. Compared with the traditional cellular automata model, the multi-grid model enhanced the continuity of the passengers'track and the precision of the boundary qualifications. The functions of the dislocation distribution of passengers as well as partial overlap of tracks due to congestion were realized. Furthermore, taking the typical cabin environment as an example, the two models were used to analyze passenger evacuation under the same conditions. It was found that the laws of passenger evacuation simulated by the two models are similar, while the simulation's authenticity and accuracy are enhanced by the multi-grid model.
基金National Natural Science Foundation of China(Grant No.51909039)Shandong Provincial Key Laboratory of Ocean Engineering(Grant No.201807).
文摘The launching and recovery process of a human-occupied vehicle(HOV)faces more complex wave effects than other types of submersible operations.However,due to the nonlinearity between the HOV and its mother ship,difficulties occur in theoretically simulating their coupled motion and hydrodynamics.The coupled motion responses and the load under different regular wave conditions are investigated experimentally in this study.The optimized design of the experimental scheme simulated the launching and recovery process of the mother ship and HOV in regular waves.The attitude sensor performed synchronous real-time measurement of the coupled motion between the mother ship and HOV as well as obtained the load data on the coupled motion under different cable lengths.The results show that models in heading waves mainly lead to the vertical motion of the hoisting point.In beam waves,the transverse and vertical motions of the hoisting point occur in a certain frequency of waves.Under the heading and beam wave conditions,the longer the hoisting cable is,the greater the movement amplitude of the submersible is.Moreover,compared with the condition of the beam waves,the hoisting submersible has less influence on the mother ship under the condition of the heading waves.The findings provide theoretical support for the design optimization of the launching and recovery operation.
文摘The purpose of this paper is to introduce an innovative methodology in shipping investment evaluation based on simulation of a project cash flow. It concerns a complementary approach to current practices and its aim is to provide more information mainly to ship-owners that consider the feasibility of deploying Ro-Ro Passenger ferries. The paper examines a typical semi-conventional RoPax ferry operating in the Aegean Sea. It addresses important economic, operational and procedural issues concerning risk evaluation. The current status is that risk is a notion still strange to main stakeholders. The Greek practice in performing a feasibility study for a project draws on investor's experience and feeling aided by a preliminary economic study. The main thesis of this paper is that there are alternative techniques to evaluate investment risk and measure profitability of a project. A Monte Carlo simulation in collaboration with a typical Ro-Ro cash-flow model is implemented to reveal the extent of risk and provide a useful tool for the assessment of future investments in Greek Short Sea Shipping.
基金Research Fund from Science and Technology on Underwater Vehicle Laboratory
文摘The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.
基金Shanghai High-level Local University Innovation Team(Maritime Safety&Technical Support)the National Natural Science Foundation of China (Grant No. 42176217)
文摘Following developments in artificial intelligence and big data technology,the level of intelligence in intelligent vessels has been improved.Intelligent vessels are being developed into unmanned surface vehicles(USVs),which have widely interested scholars in the shipping industry due to their safety,high efficiency,and energy-saving qualities.Considering the current development of USVs,the types of USVs and applications domestically and internationally are being investigated.USVs emerged with technological developments and their characteristics show some differences from traditional vessels,which brings some problems and advantages for their application.Certain maritime regulations are not applicable to USVs and must be changed.The key technologies in the current development of USVs are being investigated.While the level of intelligence is improving,the protection of cargo cannot be neglected.An innovative approach to the internal structure of USVs is proposed,where the inner hull can automatically recover its original state in case of outer hull tilting.Finally,we summarize the development status of USVs,which are an inevitable direction of development in the marine field.
文摘Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equivalent barrier has not previously been proven to meet the requirements of containing the vehicle and dissipating sufficient impact energy for passenger protection. As full-scale crash testing is very expensive, the number of data that can be measured in a test is usually limited, and it may not always be possible to obtain good quality measurements in such a test, a reliable and efficient numerical simulation of crash testing is therefore very useful. This paper presents finite element simulations of a 3-rail steel road traffic barrier under vehicle impact. The performance levels defined in Australian Standards AS5100 Clause 10.5 for these barriers are checked. The numerical simulations show that the barrier is able to meet low performance levels. However, the maximum deceleration is higher than the acceptable limit for passenger protection. If present, a kerb launches the vehicles into the barrier, allowing for the possibility of overriding the barrier under certain circumstances, but it redirects the vehicle and reduces the incident angle, which reduces impact force on the barrier. Further investigation into all common kerb profiles on roads should be carried out, as only one kerb profile is investigated in this study.
文摘For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of this choice resides in the opportunity to reduce weight and dimension, in comparison to a traditional In- ternal Combustion Engine (ICE). It’s not possible to use the GT engine directly for the vehicle traction, so the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is pure electric. Many efforts are spent in the definition of a generic scientific method to define the correct ratio HD (the Hybridization Degree) between the installed power of the battery pack and that of the GT electric generator which simultaneously guarantee the main life for the battery package and the ca- pacity of the vehicle to complete a common mission (about 15 km - 30 km) without lack of energy or stop. This paper reports all studies carried out and finally proposes a possible configuration (weight distribution, VMU logic control, GT dimensions and power rate, battery package characteristics and so on) for mid term solution in the Italian transport system.
基金supported by the National Natural Science Foundation of China (No. 21577125)the Social Development Special Fund from Science and Technology Bureau of Hangzhou, China (No. 20110533B09)
文摘In this study, the influences of accumulated mileage (deterioration) and technological changes (emission standards) on emission factors (EFs) of regulated pollutants (CO, HC, and NOx) from gasoline passenger vehicles were investigated based on Inspection and Maintenance (I/M) data using the chassis dynamometer method. The accumulated mileage of passenger vehicles was significantly linearly correlated with vehicle age. For most cases, the average EFs of CO, HC and NOx were significantly linearly correlated with accumulated mileage, indicating that emission deterioration had a significant impact on pollutant EFs. Implemented emission standards markedly influenced the EFs of regulated pollutants, and EFs markedly decreased with progressing emission standards. The present study also compared EFs of regulated pollutants between this study and the International vehicle emission (IVE) model, and marked differences in EFs were seen with variations in emission standards, vehicle types and accumulated mileage; NOx EFs in this study were higher than in the IVE model. The results provide new insight into estimating regulated pollutant emissions using the IVE model.
基金the National Key Research and Development Program of China(Nos.2017YFC0211100 and 2017YFC0212100)the National Natural Science Foundation of China(Grant Nos.51708327,91544222 and 51978404)the Ministry o f Science and Technology of China's International Science and Technology Cooperation Program(No.2016YFE0106300)。
文摘An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily by a portable emission measurement system.The on-board diagnostic(OBD)approach,which is flexible and offers high-resolution data collection,is a promising fuel consumption monitoring method.Three LDPVs were tested with a laboratory dynamometer based on a type-approval cycle,the New European Driving Cycle(NEDC).Fuel consumption was measured by the OBD and constant-volume sampling system(CVS,a regulatory method)to verify the accuracy of the OBD values.The results of the OBD method and the regulatory carbon balance method exhibited a strong linear correlation(e.g.,R^2=0.906-0.977).Compared with the carbon balance results,the fuel consumption results using the OBD were 7.1%±4.3%lower on average.Furthermore,the real-world fuel consumption of six LDPVs was tested in Beijing using the OBD.The results showed that the normalized NEDC real-world fliel consumption of the tested vehicles was 13%±17%higher than the type-approval-based fuel consumption.Because the OBD values are lower than the actual fuel consumption,using a carbon balance method may result in a larger discrepancy between real-word and type-approval ftiel consumption.By means of the operating mode binning and micro trip methods,a strong relationship(R^2=0.984)was established between the average speed and relative fuel consumption.For congested roads(average vehicle speed less than 25 km/h),the fuel consumption of LDPVs is highly sensitive to changes in average speed.
文摘The problems associated with evacuation of people from the ship in an emergency situation are analyzed, especially passenger ships are taken under consideration. The most dangerous accidents requiring evacuation are described. Marine accidents often occur as eliminating all of the hazards to human health and life is still impossible. In every case, the evacuation process from the ship must be taken under consideration. Evacuation route arrangement should provide the possibility of safe departure from danger areas for passengers and crew members. Evacuation routes designed for human interaction within the evacuation process and other important factors are reviewed. Additionally, the method for seeking evacuation time as a function of initial distribution of passengers and evacuation routes choosing is suggested. A genetic algorithm will be used, whilst the calculated evacuation time is connected with a fitness function. Parameters Of evacuation routes topology are coded as non-binary chromosomes. Genetic operators are fitted for such types of problems to avoid receiving infeasible solutions. The objective of the proposed method is to find the evacuation time in worse case scenarios.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos: 71422010, 71621001 and 71771015)
文摘On July 24,2012,the State Council of the People’s Republic of China implemented'a toll-free program for small passenger vehicles during major vacations1).In the several months that followed,local governments issued implementation articles.The current Major Vacation Tollfree Program for small passenger vehicles(MVTP)pioneers the concept(Xu and Gao,2016),'Benefaction to People.'The current MVTP has received
文摘Passenger vehicles (including vans) registrations year-on-year increased 42.2% in Feb. 2007, reaching 408,570 units. Due to the reason there was a larger sales period before the past Chinese New Year in late of February, thus Feb. 2007 made a rather different tendency than previous years. The registrations exceeded more than 0.2 million compared with the
文摘1. An overall judgment on the situation 2006 saw the rapid growth of passenger vehicles, with the production capacity putting into use rose from less than 70 percent to around 80 percent. That with light commercial vehicles was similar too. The situation in 2005 and 2006 showed that there are no evidential overdone production capacity.