The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six repre...The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,2019.The results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and VSL.These findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.展开更多
To decide about irvestments in appropriate seismic vulnerability reduction and resilience enhancement mea-sures,policymakers need to acquire adequate insight into the value of a statistical life(VSL).The VSL measures ...To decide about irvestments in appropriate seismic vulnerability reduction and resilience enhancement mea-sures,policymakers need to acquire adequate insight into the value of a statistical life(VSL).The VSL measures the monetary value the public assigns to reducing mortality due to a specific risk(e.g-.dying from an earthquake)over a given period.In the absence of appropriate models to estimate the context-specific VSL for a given community,past studies have resorted to approaches such as using the VSL estimated for other purposes(e.g.,transportation and environmental safety)or other countries(e.g,the US).This can lead to under-or over-estimation of VSL,misappropriation of the funds for seismic vulnerability reduction programs,and adverse economic,political,and social consequences.This study proposes a methodology that follows the stated pref-erence binary choice approach to estimate the willingness to pay(WTP)to reduce the risk of earthquake-induced mortalities.The proposed method,which is applied to quantify VSL in Iran,involves using a questionnaire to collect the needed information about people's choices when investing in various risk reduction measures.It uses a test containing positivity and proportionality components to check the responses'consistency.Regression modeling is used to estimate the respondents'WTP and VSL.展开更多
The research of carbon content along the casting direction of 82B cord steel billets is of great significance for improvingthe quality of cord products from subsequent processing.However,the traditional segregation an...The research of carbon content along the casting direction of 82B cord steel billets is of great significance for improvingthe quality of cord products from subsequent processing.However,the traditional segregation and billets quality evaluationmethods have certain limitations,such as sampling length and analysis area.which affect the accuracy of quality judgment.Thus.the statistics of extreme values(SEV)was introduced to predict the maximum value of carbon element contentalong the casting direction,which can quantitatively characterize the segregation degree.The size of the selected billet is150 mm×150 mm,and the sampling location is the centerline of the billet.The experiment was conducted by consideringthe effect of cooling intensity and casting speed on the maximum value of carbon element content.Firstly,the calculationresults show that the SEN method can predict the maximum value of carbon element content along the casting directionof 82B cord steel,and the SEV method is proved to be effective by analyzing the carbon distribution and fluctuation in billets.To some extent,the SEV method can break the limitations of the sampling length and analysis area by predicting themaximum value of carbon element on a larger range of continuous casting billets with few samples.During the continuouscasting process the increase in cooling intensity makes the surface shrinking rate increase,which can slow down the flowof solute-enriched liquid to the center,and the center segregation can be reduced.On the other hand,the function area ofthe final electromagnetic stirring can be expanded with the increase in the casting speed,which can reduce the concentration of carbon element in the center of the billets and reduce the maximum value of carbon element content.Ilt can providea new theoretical reference for the quantitative calculation of carbon content in continuous casting billets and the qualityevaluation of continuous casting billcts.展开更多
A statistic method, statistics of extreme values （SEV）, was described in detail, which can esti mate the size of maximum inclusion in steel. The characteristic size of the maximum inclusion in a high clean bearing s...A statistic method, statistics of extreme values （SEV）, was described in detail, which can esti mate the size of maximum inclusion in steel. The characteristic size of the maximum inclusion in a high clean bearing steel （GCrl5） was evaluated by this method, and the morphology and corn position of large inclusions found were analyzed by scanning electron microscopy （SEM）. When standard inspection area （S0） is 280 mm2, the characteristic size of the biggest inclusion found in 30 standard inspection area is 23.93 μm, and it has a 99.9% probability of the characteristic size of maximum inclusion predicted being no larger than 36.85μm in the experimental steel. SEM result shows that large inclusions found are mainly composed of CaS, calcium-aluminate and MgO. Compositing widely exists in large inclusions in high clean bearing steel. Compared with traditional evaluation method, SEV method mainly focuses on inclusion size, and the esti- mation result is not affected by inclusion types. SEV method is suitable for the inclusion eval uation of high clean bearing steel.展开更多
Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion size...Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion sizes and fatigue strength in different volumes were estimated by statistics of extreme values （SEV） and generalized Pareto distribution （GPD） methods. The results showed that S N curves of 60Si2CrVA spring steels for two rolling processes were not horizontal asymptotes but a gradient in a regime of 109 cycles, and traditional fatigue limits were eliminated. Surface machined topography and inclusions in steel were major factors that led to elimination of fatigue limit for 60Si2CrVA spring steel. The SEV and GPD methods could effectively predict size of the maximum inclusion and fatigue strength in different volumes of 60Si2CrVA spring steel. Predicted fatigue strength was in accordance with experimental results by ultrasonic fatigue testing.展开更多
This paper presents a survey-based economic evaluation of security measures protecting against the risk of aviation terrorism. A sample of Norwegians were asked to state their choices between different air travel al-t...This paper presents a survey-based economic evaluation of security measures protecting against the risk of aviation terrorism. A sample of Norwegians were asked to state their choices between different air travel al-ternatives, i.e. travel time, trip costs, fatalities in terrorist acts on air transport and type of passenger screen-ing. Screening was specified as either the current uniform screening or a new risk-based screening in which passengers are divided into three groups: high-risk, medium-risk and low-risk. Respondents were informed that risk-based screening implied they would have to identify themselves using a biometric identity card and that those not qualifying as low-risk passengers would be checked with body scanners. Our results indicate that the sampled passengers were very concerned about privacy. Maintaining existing uniform screening was preferred to a new risk-based screening system, even though risk-based screening was presented as poten-tially preventing future terrorist fatalities.展开更多
基金supported by the National Natural Science Foun‐dation of China[Grant No.71773061].
文摘The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,2019.The results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and VSL.These findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.
文摘To decide about irvestments in appropriate seismic vulnerability reduction and resilience enhancement mea-sures,policymakers need to acquire adequate insight into the value of a statistical life(VSL).The VSL measures the monetary value the public assigns to reducing mortality due to a specific risk(e.g-.dying from an earthquake)over a given period.In the absence of appropriate models to estimate the context-specific VSL for a given community,past studies have resorted to approaches such as using the VSL estimated for other purposes(e.g.,transportation and environmental safety)or other countries(e.g,the US).This can lead to under-or over-estimation of VSL,misappropriation of the funds for seismic vulnerability reduction programs,and adverse economic,political,and social consequences.This study proposes a methodology that follows the stated pref-erence binary choice approach to estimate the willingness to pay(WTP)to reduce the risk of earthquake-induced mortalities.The proposed method,which is applied to quantify VSL in Iran,involves using a questionnaire to collect the needed information about people's choices when investing in various risk reduction measures.It uses a test containing positivity and proportionality components to check the responses'consistency.Regression modeling is used to estimate the respondents'WTP and VSL.
基金The authors are very grateful for support from United Funds between National Natural Science Foundation and Baowu Steel Group Corporation Limited from China(No.U1860101)Chongqing Fundamental Research and Cutting-Edge Technology Funds(No.cstc2017jcyjAX0019).
文摘The research of carbon content along the casting direction of 82B cord steel billets is of great significance for improvingthe quality of cord products from subsequent processing.However,the traditional segregation and billets quality evaluationmethods have certain limitations,such as sampling length and analysis area.which affect the accuracy of quality judgment.Thus.the statistics of extreme values(SEV)was introduced to predict the maximum value of carbon element contentalong the casting direction,which can quantitatively characterize the segregation degree.The size of the selected billet is150 mm×150 mm,and the sampling location is the centerline of the billet.The experiment was conducted by consideringthe effect of cooling intensity and casting speed on the maximum value of carbon element content.Firstly,the calculationresults show that the SEN method can predict the maximum value of carbon element content along the casting directionof 82B cord steel,and the SEV method is proved to be effective by analyzing the carbon distribution and fluctuation in billets.To some extent,the SEV method can break the limitations of the sampling length and analysis area by predicting themaximum value of carbon element on a larger range of continuous casting billets with few samples.During the continuouscasting process the increase in cooling intensity makes the surface shrinking rate increase,which can slow down the flowof solute-enriched liquid to the center,and the center segregation can be reduced.On the other hand,the function area ofthe final electromagnetic stirring can be expanded with the increase in the casting speed,which can reduce the concentration of carbon element in the center of the billets and reduce the maximum value of carbon element content.Ilt can providea new theoretical reference for the quantitative calculation of carbon content in continuous casting billets and the qualityevaluation of continuous casting billcts.
基金funded by National Natural Science Foundation of China(51474076)International S&T Cooperation Program(ISTCP)of China(2015DFG51950)
文摘A statistic method, statistics of extreme values （SEV）, was described in detail, which can esti mate the size of maximum inclusion in steel. The characteristic size of the maximum inclusion in a high clean bearing steel （GCrl5） was evaluated by this method, and the morphology and corn position of large inclusions found were analyzed by scanning electron microscopy （SEM）. When standard inspection area （S0） is 280 mm2, the characteristic size of the biggest inclusion found in 30 standard inspection area is 23.93 μm, and it has a 99.9% probability of the characteristic size of maximum inclusion predicted being no larger than 36.85μm in the experimental steel. SEM result shows that large inclusions found are mainly composed of CaS, calcium-aluminate and MgO. Compositing widely exists in large inclusions in high clean bearing steel. Compared with traditional evaluation method, SEV method mainly focuses on inclusion size, and the esti- mation result is not affected by inclusion types. SEV method is suitable for the inclusion eval uation of high clean bearing steel.
基金Sponsored by National Basic Research Program(973 Program)of China(2004CB619100)
文摘Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion sizes and fatigue strength in different volumes were estimated by statistics of extreme values （SEV） and generalized Pareto distribution （GPD） methods. The results showed that S N curves of 60Si2CrVA spring steels for two rolling processes were not horizontal asymptotes but a gradient in a regime of 109 cycles, and traditional fatigue limits were eliminated. Surface machined topography and inclusions in steel were major factors that led to elimination of fatigue limit for 60Si2CrVA spring steel. The SEV and GPD methods could effectively predict size of the maximum inclusion and fatigue strength in different volumes of 60Si2CrVA spring steel. Predicted fatigue strength was in accordance with experimental results by ultrasonic fatigue testing.
基金This study was funded by the Research Council of Norway through the project“Coping with the new risks:Understanding,organization and economics”(186774),under the programme“Risk and Safety in Transport”(RISIT).
文摘This paper presents a survey-based economic evaluation of security measures protecting against the risk of aviation terrorism. A sample of Norwegians were asked to state their choices between different air travel al-ternatives, i.e. travel time, trip costs, fatalities in terrorist acts on air transport and type of passenger screen-ing. Screening was specified as either the current uniform screening or a new risk-based screening in which passengers are divided into three groups: high-risk, medium-risk and low-risk. Respondents were informed that risk-based screening implied they would have to identify themselves using a biometric identity card and that those not qualifying as low-risk passengers would be checked with body scanners. Our results indicate that the sampled passengers were very concerned about privacy. Maintaining existing uniform screening was preferred to a new risk-based screening system, even though risk-based screening was presented as poten-tially preventing future terrorist fatalities.
