The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan provinc...The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan province in China as case study area where the landform is diverse and complex,administrative counties were categorized into 4 main types:plain counties,hill counties,mountain counties,and plateau counties.Using statistical data during 2006-2014,theperformanceofeconomic development and transport construction level in the four types of counties are discussed.Subsequently,the heterogeneous effect of each grade road on economy was calculated by local regression model(GWR).The results indicate that plain counties largely surpassed the other geomorphic counties in economic development level,while the gradient gap among them was on the decline.Similarly,distribution of transport infrastructure presented a decreasing trend from the low plain counties to high plateau counties.Regional imbalances were mainly reflected in the County road and Village road.Regarding the changes of regional gaps,National&Provincial roads and County roads were constantly expanding,whereas the disparity of Village road was slowly narrowing over time.Particularly noteworthy was the non-stationary economic influence of traffic factors across vertical gradients.On average,National&Provincial roads generated higher benefits in the high elevation regions than the lowlands.In contrast,County road and Village road were found to be more effective in promoting economic development in plains.With regard to local estimates of traffic factors,coefficients in mountain counties exhibited larger fluctuation ranges than other geomorphic units.The conclusions provide a basis for government decisionmaking in a more reasonable construction arrangement of road facilities and sustainable economic development.展开更多
Using lower-cost lasers, 30% savings are possible for 10-Gb/s uncompensated metro transmission over NZDF, compared to G.652 fiber. We present WDM transmission results for a mixed plant of NZDF rings interconnected to ...Using lower-cost lasers, 30% savings are possible for 10-Gb/s uncompensated metro transmission over NZDF, compared to G.652 fiber. We present WDM transmission results for a mixed plant of NZDF rings interconnected to G.652.C-fiber access laterals.展开更多
The market potential for profitable operations of electric vertical take-off and landing(eVTOL)vehicles within Urban Air Mobility(UAM)depends mainly on total costs,including investments in infrastructure,eVTOL vehicle...The market potential for profitable operations of electric vertical take-off and landing(eVTOL)vehicles within Urban Air Mobility(UAM)depends mainly on total costs,including investments in infrastructure,eVTOL vehicle production,and air traffic management.Total cost models including vehicle production from the manufacturer’s perspective and operating systems on fleet level are required to comprehensively analyze feasible UAM operations.This paper models eVTOL concept-specific costs within a generalized Total Cost of Ownership estimation combining operational demand simulation and extended eVTOL data.The model incorporates approaches of DAPCA IV with extensions for eVTOL vehicles and divides production costs into airframe,avionics,and propulsion.Parameterization is carried out through literature review of previous cost models and reference data.Revenue is derived from agent-based demand simulation instances utilizing MATSim.Results are carried out for eleven eVTOL vehicles,including five Lift+Cruise,three Tilt-Rotor,one Tilt-Wing,and two Multicopter concepts.In the metropolitan region Rhine-Ruhr,autonomous flight operations are required for cost-efficient operations,high production volumes are beneficial,and optimized ticket price ranges average two euros per kilometer.Sensitivities for a near-term scenario indicate the relevance of investments in infrastructure and ramp-up strategies for manufacturers,as profit margins are rather small,and some eVTOL concepts are cost-inefficient.Based on this work,the detailed cost estimation tool can be applied to evaluate feasible UAM operations in future research scenarios accounting for previous parameter uncertainties.Parametric vehicle design optimization can be advanced considering cost couplings between vehicle level and fleet level.展开更多
基金supported by the National Natural Science Foundation of China (Grants No. 41571523 and 41661144038)the National Basic Research Program of China (973 Program) (Grant No. 2013CBA01808)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2014BAC05B01)
文摘The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan province in China as case study area where the landform is diverse and complex,administrative counties were categorized into 4 main types:plain counties,hill counties,mountain counties,and plateau counties.Using statistical data during 2006-2014,theperformanceofeconomic development and transport construction level in the four types of counties are discussed.Subsequently,the heterogeneous effect of each grade road on economy was calculated by local regression model(GWR).The results indicate that plain counties largely surpassed the other geomorphic counties in economic development level,while the gradient gap among them was on the decline.Similarly,distribution of transport infrastructure presented a decreasing trend from the low plain counties to high plateau counties.Regional imbalances were mainly reflected in the County road and Village road.Regarding the changes of regional gaps,National&Provincial roads and County roads were constantly expanding,whereas the disparity of Village road was slowly narrowing over time.Particularly noteworthy was the non-stationary economic influence of traffic factors across vertical gradients.On average,National&Provincial roads generated higher benefits in the high elevation regions than the lowlands.In contrast,County road and Village road were found to be more effective in promoting economic development in plains.With regard to local estimates of traffic factors,coefficients in mountain counties exhibited larger fluctuation ranges than other geomorphic units.The conclusions provide a basis for government decisionmaking in a more reasonable construction arrangement of road facilities and sustainable economic development.
文摘Using lower-cost lasers, 30% savings are possible for 10-Gb/s uncompensated metro transmission over NZDF, compared to G.652 fiber. We present WDM transmission results for a mixed plant of NZDF rings interconnected to G.652.C-fiber access laterals.
基金supported by the funding scheme“NRW Forschungskollegs”by the Ministry of Culture and Science of the German State of North Rhine Westphalia(Grant no.321-8.03.07-127598).
文摘The market potential for profitable operations of electric vertical take-off and landing(eVTOL)vehicles within Urban Air Mobility(UAM)depends mainly on total costs,including investments in infrastructure,eVTOL vehicle production,and air traffic management.Total cost models including vehicle production from the manufacturer’s perspective and operating systems on fleet level are required to comprehensively analyze feasible UAM operations.This paper models eVTOL concept-specific costs within a generalized Total Cost of Ownership estimation combining operational demand simulation and extended eVTOL data.The model incorporates approaches of DAPCA IV with extensions for eVTOL vehicles and divides production costs into airframe,avionics,and propulsion.Parameterization is carried out through literature review of previous cost models and reference data.Revenue is derived from agent-based demand simulation instances utilizing MATSim.Results are carried out for eleven eVTOL vehicles,including five Lift+Cruise,three Tilt-Rotor,one Tilt-Wing,and two Multicopter concepts.In the metropolitan region Rhine-Ruhr,autonomous flight operations are required for cost-efficient operations,high production volumes are beneficial,and optimized ticket price ranges average two euros per kilometer.Sensitivities for a near-term scenario indicate the relevance of investments in infrastructure and ramp-up strategies for manufacturers,as profit margins are rather small,and some eVTOL concepts are cost-inefficient.Based on this work,the detailed cost estimation tool can be applied to evaluate feasible UAM operations in future research scenarios accounting for previous parameter uncertainties.Parametric vehicle design optimization can be advanced considering cost couplings between vehicle level and fleet level.
