Despite blockchain’s potential to transform corporations by providing new ways of organizing business processes and handling information,extant research pays inadequate attention to how and under what conditions bloc...Despite blockchain’s potential to transform corporations by providing new ways of organizing business processes and handling information,extant research pays inadequate attention to how and under what conditions blockchain technology provides additional financial value for shareholders.Drawing on the efficient market hypothesis and signaling theory,we examined the relationship between firms’blockchain use,development announcements,and stock market reactions.We used the event study methodology to analyze a sample of blockchain projects initiated by US firms between 2016 and 2019.The sample contains 114 firm-event observations.The findings show that the average abnormal return over a 2 days event period(including the day of the announcement and the day after the announcement)was positive.This positive stock market reaction is even more substantial when firms announce blockchain projects that focus on saving cost or time.Our findings also indicate that blockchain announcements tend to elicit more positive market reactions from smaller firms.We analyzed 249 firm-event observations containing firms from around the world and conclude that blockchain technology has a non-significant long-term impact on operating performance.The contingency approach adopted in our research provides advice for selecting the right mix of blockchain investment initiatives that is most suitable for a given organizational context.展开更多
The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the tr...The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.展开更多
Most current Travel Demand Management(TDM)programs such as vanpooling,ridesharing,or transit focus on managing travel demand of specific groups of commuters but are limited in effectively managing demand for automobil...Most current Travel Demand Management(TDM)programs such as vanpooling,ridesharing,or transit focus on managing travel demand of specific groups of commuters but are limited in effectively managing demand for automobile drivers,who are unable or unwilling to participate in such programs.This paper highlights results from a pilot field study conducted in a large west coast city experiencing major traffic congestion,and documents results of the use of an incentive-based active demand management(ADM)system focusing on automobile commuters.The system,called“Metropia,”predicts future traffic conditions,applies a proprietary routing algorithm to find time-dependent shortest paths for different departure times,and,based on user request,provides automobile travelers with multiple departure times and route choices.Each of these travel choices are assigned points values,with higher points(and thus more valuable rewards)available for travelling during off-peak times and less congested routes,and lower points available for peak traffic travel times.The goal of this ADM system is to improve traffic flow and commuter travel times citywide,alleviating heavily congested areas without the use of new roadway construction by incentivizing travelers to change their travel behavior and avoid traffic congestion.The level of rewards points available to users(commuters)by the system depends on the travelers’behavioral change degree and their contributions to traffic congestion alleviation.This system was implemented in Los Angeles,Calif.,USA,as a small scale pilot field study carried out beginning April 2013 and lasting for 10 weeks.Results from this field study show the system is able to accurately predict travel time with Relative Mean Absolute Error(RMAE)as low as 15.20%.Significant travel behavior changes were observed which validate the concept of using incentives to influence people’s travel behavior.Furthermore,field study results show 20%travel time can be saved for people who changed their travel behavior.展开更多
Traditional distillation(TD)is generally an energy-intensive and inefficient process for separation and purification of liquids in chemical industries.Herein,we developed an interface-enhanced distillation(IED)by empl...Traditional distillation(TD)is generally an energy-intensive and inefficient process for separation and purification of liquids in chemical industries.Herein,we developed an interface-enhanced distillation(IED)by employing a well-arranged membrane of reduced graphene oxide(rGO)sheet arrays embedded with silicon dioxide nanofibres(rGO/SiO2)as the evaporation intermediate layer on the liquid surface.This IED enlarges the evaporation surfaces and weakens the intermolecular forces on the liquid/solid/gas interfaces,realizing the fast and even low temperature fraction collection with less energy consumption.The IED delivers evaporation rates 200%–300%times that of TD,meanwhile having an energy saving of 40%–60%and a time saving of 50%–70%for diverse liquid feeds.In atmospheric IED manner,high boiling point and perishable organics can be collected with high quality at a temperature lower than their boiling points.This IED provides an innovative strategy for highly efficient distillation in chemical industries.展开更多
文摘Despite blockchain’s potential to transform corporations by providing new ways of organizing business processes and handling information,extant research pays inadequate attention to how and under what conditions blockchain technology provides additional financial value for shareholders.Drawing on the efficient market hypothesis and signaling theory,we examined the relationship between firms’blockchain use,development announcements,and stock market reactions.We used the event study methodology to analyze a sample of blockchain projects initiated by US firms between 2016 and 2019.The sample contains 114 firm-event observations.The findings show that the average abnormal return over a 2 days event period(including the day of the announcement and the day after the announcement)was positive.This positive stock market reaction is even more substantial when firms announce blockchain projects that focus on saving cost or time.Our findings also indicate that blockchain announcements tend to elicit more positive market reactions from smaller firms.We analyzed 249 firm-event observations containing firms from around the world and conclude that blockchain technology has a non-significant long-term impact on operating performance.The contingency approach adopted in our research provides advice for selecting the right mix of blockchain investment initiatives that is most suitable for a given organizational context.
文摘The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.
文摘Most current Travel Demand Management(TDM)programs such as vanpooling,ridesharing,or transit focus on managing travel demand of specific groups of commuters but are limited in effectively managing demand for automobile drivers,who are unable or unwilling to participate in such programs.This paper highlights results from a pilot field study conducted in a large west coast city experiencing major traffic congestion,and documents results of the use of an incentive-based active demand management(ADM)system focusing on automobile commuters.The system,called“Metropia,”predicts future traffic conditions,applies a proprietary routing algorithm to find time-dependent shortest paths for different departure times,and,based on user request,provides automobile travelers with multiple departure times and route choices.Each of these travel choices are assigned points values,with higher points(and thus more valuable rewards)available for travelling during off-peak times and less congested routes,and lower points available for peak traffic travel times.The goal of this ADM system is to improve traffic flow and commuter travel times citywide,alleviating heavily congested areas without the use of new roadway construction by incentivizing travelers to change their travel behavior and avoid traffic congestion.The level of rewards points available to users(commuters)by the system depends on the travelers’behavioral change degree and their contributions to traffic congestion alleviation.This system was implemented in Los Angeles,Calif.,USA,as a small scale pilot field study carried out beginning April 2013 and lasting for 10 weeks.Results from this field study show the system is able to accurately predict travel time with Relative Mean Absolute Error(RMAE)as low as 15.20%.Significant travel behavior changes were observed which validate the concept of using incentives to influence people’s travel behavior.Furthermore,field study results show 20%travel time can be saved for people who changed their travel behavior.
基金This work was supported by the Ministry of Science and Technology of China(2016YFA0200200 and 2017YFB1104300)the National Science Foundation of China(51673026,51433005 and 21805160)+1 种基金NSFC-MAECI(51861135202),NSFC-STINT(21911530143)and Beijing Natural Science Foundation(2152028).Computations were carried out on the“Explorer 100”cluster system of Tsinghua National Laboratory for Information Science and Technology.
文摘Traditional distillation(TD)is generally an energy-intensive and inefficient process for separation and purification of liquids in chemical industries.Herein,we developed an interface-enhanced distillation(IED)by employing a well-arranged membrane of reduced graphene oxide(rGO)sheet arrays embedded with silicon dioxide nanofibres(rGO/SiO2)as the evaporation intermediate layer on the liquid surface.This IED enlarges the evaporation surfaces and weakens the intermolecular forces on the liquid/solid/gas interfaces,realizing the fast and even low temperature fraction collection with less energy consumption.The IED delivers evaporation rates 200%–300%times that of TD,meanwhile having an energy saving of 40%–60%and a time saving of 50%–70%for diverse liquid feeds.In atmospheric IED manner,high boiling point and perishable organics can be collected with high quality at a temperature lower than their boiling points.This IED provides an innovative strategy for highly efficient distillation in chemical industries.