Opinion dynamics is an opinion evolution process of a group of agents,where the final opinion distribution tends to three stable states:consensus,polarization,and fragmentation.At present,the opinion dynamics models h...Opinion dynamics is an opinion evolution process of a group of agents,where the final opinion distribution tends to three stable states:consensus,polarization,and fragmentation.At present,the opinion dynamics models have been extensively studied in differrent fields.This paper provides a review of opinion dynamics in finance and business,such as,finance,marketing,e-commerce,politics,and group decision making.Furthermore,identified research challenges have been proposed to promote the future research of this topic.展开更多
Partial least squares structural equation modeling(PLS-SEM)is a modern multivariate analysis technique with a demonstrated ability to estimate theoretically established cause-effect relationship models.This technique ...Partial least squares structural equation modeling(PLS-SEM)is a modern multivariate analysis technique with a demonstrated ability to estimate theoretically established cause-effect relationship models.This technique has been increasingly adopted in construction management research over the last two decades.Accordingly,a critical review of studies adopting PLS-SEM appears to be a timely and valuable endeavor.This paper offers a critical review of 139 articles that applied PLS-SEM from 2002 to 2019.Results show that the misuse of PLS-SEM can be avoided.Critical issues related to the application of PLS-SEM,research design,model development,and model evaluation are discussed in detail.This paper is the first to highlight the use and misuse of PLS-SEM in the construction management area and provides recommendations to facilitate the future application of PLS-SEM in this field.展开更多
Concrete exterior quality is one of the important metrics in evaluating construction project quality.Among the defects affecting concrete exterior quality,bughole is one of the most common imperfections,thus detecting...Concrete exterior quality is one of the important metrics in evaluating construction project quality.Among the defects affecting concrete exterior quality,bughole is one of the most common imperfections,thus detecting concrete bughole accurately is significant for improving concrete exterior quality and consequently the quality of the whole project.This paper presents a deep learning-based method for detecting concrete surface bugholes in a more objective and automatic way.The bugholes are identified in concrete surface images by Mask R-CNN.An evaluation metric is developed to indicate the scale of concrete bughole.The proposed approach can detect bugholes in an instance level automatically and output the mask of each bughole,based on which the bughole area ratio is automatically calculated and the quality grade of the concrete surfaces is assessed.For demonstration,a total of 273 raw concrete surface images taken by mobile phone cameras are collected as a dataset.The test results show that the average precision(AP)of bughole masks is 90.8%.展开更多
Decarbonization in operational residential buildings worldwide has become critical in achieving the carbon neutral target due to the growing household energy demand.To accelerate the pace of global carbon neutrality,t...Decarbonization in operational residential buildings worldwide has become critical in achieving the carbon neutral target due to the growing household energy demand.To accelerate the pace of global carbon neutrality,this study explores the operational carbon change in global residential buildings through the generalized Divisia index method and decoupling analysis,considering the decarbonization levels of residential buildings at different scales.The results show that(1)most of the samples showed a decrease in the total emissions from 2000 to 2019.Except for China and the United States(US),the carbon emissions in global residential building operations decreased by 7.95 million tons of carbon dioxide(MtCO_(2))per year over the study period.Emissions per gross domestic product(GDP)was the most positive driver causing the decarbonization of residential buildings,while GDP was the most negative driver.(2)Carbon intensity was essential to achieving a strong decoupling of economic development and carbon emissions.The US almost consistently presented strong decoupling,while China showed weak decoupling over the last two decades.(3)The pace of decarbonization in global residential building operations is gradually slowing down.From 2000 to 2019,decarbonization from residential buildings across 30 countries was 2094.3 MtCO_(2),with a decarbonization efficiency of 3.4%.Overall,this study addresses gaps in evaluating global decarbonization from operational residential buildings and provides a reference for evaluating building decarbonization by other emitters.展开更多
Lessening energy-related carbon emissions has become a crucial measure to achieve Chinese carbon neutrality.This study is the first to construct a Difference in Carbon pressures-adjusted Human Development Index(DCHDI)...Lessening energy-related carbon emissions has become a crucial measure to achieve Chinese carbon neutrality.This study is the first to construct a Difference in Carbon pressures-adjusted Human Development Index(DCHDI)model for the purpose of exploring the coupling effect between carbon emissions and human development variety from 2000 to 2019 in Chinese provinces.We demonstrate the following.(1)The total energy-related carbon footprint of 30 provinces in China reached 10.2 billion tons in 2019,with an average annual growth rate of 6.93% over the past two decades;and the provinces with the highest carbon emissions per capita are InnerMongolia,Ningxia,and Shanxi.(2)At the provincial level,we observed that the Human Development Index(HDI),which includes life expectancy,education,and income,has been rising,while Beijing,Shanghai,and Tianjin entered the super-high HDI level before 2008.(3)The entire coupling effect of 30 Chinese provinces has been broadly fortified in the last 20 years,but the growth rate of DCHDI values in 2011-2019 has slowed down compared with that in 2000-2010;the clustering phenomenon demonstrated that this discovery is associated with historical peaks in total carbon emissions.(4)The co-ordination degree of carbon emissions per capita and HDI was verified,and 96% of the data points were found in the range of super high coupling coordination degree.Overall,this study provides the government with worthwhile guidance for decision-making and carbon reduction strategies for other countries struggling to advance human sustainable development.展开更多
The COvID-19 pandemic has posed severe threats to global sustainable development.However,a comprehensive quantitative assessment of the impacts of COVID-19 on Sustainable Development Goals(SDGs)is still lacking.This r...The COvID-19 pandemic has posed severe threats to global sustainable development.However,a comprehensive quantitative assessment of the impacts of COVID-19 on Sustainable Development Goals(SDGs)is still lacking.This research quantified the post-COVID-19 SDG progress from 2020 to 2024 using projected GDP growth and population and machine learning models including support vector machine,random forest,and extreme gradient boosting.The results show that the overall SDG performance declined by 7.7%in 2020 at the global scale,with 12 socioeconomic SDG performance decreasing by 3.0%-22.3%and 4 environmental SDG performance increasing by 1.6%-9.2%.By 2024,the progress of 12 SDGs will lag behind for one to eight years compared to their pre-COVID-19 trajectories,while extra time will be gained for 4 environment-related SDGs.Furthermore,the pandemic will cause more impacts on countries in emerging markets and developing economies than those on advanced economies,and the latter will recover more quickly to be closer to their pre-covID-19 trajectories by 2024.Post-COVID-19 economic recovery should emphasize in areas that can help decouple economic growth from negative environmental impacts.The results can help government and non-state stakeholders identify critical areas for targeted policy to resume and speed up the progress to achieve SDGs by 2030.展开更多
Understanding the influencing mechanism of the urban streetscape on crime is fairly important to crime prevention and urban management.Recently,the development of deep learning technology and big data of street view i...Understanding the influencing mechanism of the urban streetscape on crime is fairly important to crime prevention and urban management.Recently,the development of deep learning technology and big data of street view images,makes it possible to quantitatively explore the relationship between streetscape and crime.This study computed eight streetscape indexes of the street built environment using Google Street View images firstly.Then,the association between the eight indexes and recorded crime events was revealed with a poisson regression model and a geographically weighted poisson regression model.An experiment was conducted in downtown and uptown Manhattan,New York.Global regression results show that the influences of Motorization Index on crimes are significant and positive,while the effects of the Light View Index and Green View Index on crimes depend heavily on the socioeconomic factors.From a local perspective,the Pedestrian Space Index,Green View Index,Light View Index and Motorization Index have a significant spatial influence on crimes,while the same visual streetscape factors have different effects on different streets due to the combination differences of socioeconomic,cultural and streetscape elements.The key streetscape elements of a given street that affect a specific criminal activity can be identified according to the strength of the association.The results provide both theoretical and practical implications for crime theories and crime prevention efforts.展开更多
The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other indu...The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other industries. This paper utilizes the multi-regional input-output(MRIO)model to measure the embodied energy consumption in China's construction industry at the province level. To quantify the backward and forward linkages between the construction industry and other industries, the energy-driven and energy-driving abilities of the construction industry are investigated for 30 provinces. The results show that the values of the energy-driven coefficients are significantly larger than the energy-driving coefficients, indicating that the construction industry is highly dependent on products from other industries and other regions, not vice versa. The construction industries in the southwest and northwest regions of China have the highest energy-driven coefficients, showing that the construction industries in west China heavily rely on indirect energy embodied in goods and services. This particularly applies in Guangxi and Hainan provinces, which have the highest energydriven abilities and the lowest energy-driving abilities. The findings can facilitate the policy-makers to examine the critical energy-saving paths.展开更多
Although China has made great achievements in economic scale,the model of high-quality economic developments is still in the exploratory stage.A series problems,such as unreasonable industrial structure and low produc...Although China has made great achievements in economic scale,the model of high-quality economic developments is still in the exploratory stage.A series problems,such as unreasonable industrial structure and low production effciency,need to be resolved urgently.The transformation and upgrading of industrial structure is the inevitable choice.The analysis of industrial relations is an important method to reveal the internal mechanism of industrial structure change.Therefore,based on the concepts of sensitivity and influence coeffcient,this paper proposed the concepts of driven and driving coeffcient,and constructed the industrial complex networks of China from 1999 to 2013 according to the EORA input-output table.From the perspectives of the interaction power,industrial linkages and community structure,this paper systematically analyzes the evolution of China’s industrial structure.Results show that China’s industrial structure is undergoing a transformation from industry-oriented to industry-service-oriented.The interaction linkages between industries has formed a robust association structure.The traditional sectors such as infrastructure construction and industries are still the largest consumer group driving the development of other industries.Besides,light industry,infrastructure construction and finance have become increasingly important hub industries in the industrial system.However,some unbalanced community structures are formed in the economic system,which has resulted in a waste of resources and low production effciency to a certain extent.Effectively grasping the relationship between China’s industrial structure evolution and its association is conducive to formulating economic restructuring policies,promoting the upgrading of China’s economic and,realizing the leap from quantitative change to qualitative change.展开更多
The arrival of the high-speed rail(HSR)era has accelerated the pace of urban development,but its broad socioeconomic impact remains subject to intense debates.This research aims to propose a model for measuring the im...The arrival of the high-speed rail(HSR)era has accelerated the pace of urban development,but its broad socioeconomic impact remains subject to intense debates.This research aims to propose a model for measuring the impact of HSR operation on HSR stations and the surrounding areas,which this research call the HSR丒 based nodal zone(HNZ).The proposed model is composed of two variables(i.e.,transportation situation and vitality)and three subsystems(i.e.,economic,societal,and environmental).Data were collected in China through questionnaire survey.Results indicate that the effects of HSR operation on HNZ are multidimensional,transportation vitality has an intermediary role in the effects,and the effects on the physical environment are negative.This study presents an early examination of the impact of HSR operation on the HSR stations and relevant areas and contributes new evidence to academic debates on the contribution of HSR to urban development.Accordingly,urban development policies should be built on the mechanism of HSR in driving the growth of HNZ.展开更多
Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various defini...Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various definitions of the urban built-up area and proposes three definition methods: all urban built-up areas in a municipal administrative area, concentrated contiguous built-up areas, and urban built-up areas in central cities. From the latest Landsat 8 satellite images, the paper obtains the data of urban built-up area in some of China’s big cities and makes a comparative study between the results of the urban built-up areas by the three definition methods and three other common statistical data. It finds that neither the area data nor the ranking is consistent. Finally, it further explores what causes differences in rankings and gives some advice for improving the definition of the urban built-up area.展开更多
The construction industry is one of the major producers of municipal solid waste.Although there are many studies in municipal solid waste management,the research on the recovery of recyclable building material from co...The construction industry is one of the major producers of municipal solid waste.Although there are many studies in municipal solid waste management,the research on the recovery of recyclable building material from construction sites remains limited.This paper addresses the optimal design issue of the construction and demolition(C&D)waste logistics network based on the features of the construction industry from the contractors’perspective.The purpose of this paper is to provide an optimal C&D waste recycling network decision(RND)model considering the change of construction sites location over time.A multi-period and multi-objective mixed-integer linear programming model was developed to minimize the cost of C&D waste disposal for contractors,and to minimize the carbon emissions from C&D waste transportation.An application study was conducted to assess the performance of the RND model.Through some sensitivity analysis experiments based on an immune genetic algorithm,the influences of environmental policies and carbon tax policy on improving the recycling rate of C&D waste and reduce the carbon emission were explored.The findings of this research suggest that:(1)a RND model with the feature of the construction industry developed in this paper can effectively optimize the C&D waste logistics network;(2)government policies and laws are valid political instruments to improve the recycling rate of C&D waste;(3)the carbon-tax analyses demonstrate that a carbon tax policy can effectively reduce carbon emissions.展开更多
基金This work was supported by the grant(No.2020M673146)from China Postdoctoral Science Foundationthe grant(No.72001031)from NSF of China。
文摘Opinion dynamics is an opinion evolution process of a group of agents,where the final opinion distribution tends to three stable states:consensus,polarization,and fragmentation.At present,the opinion dynamics models have been extensively studied in differrent fields.This paper provides a review of opinion dynamics in finance and business,such as,finance,marketing,e-commerce,politics,and group decision making.Furthermore,identified research challenges have been proposed to promote the future research of this topic.
文摘Partial least squares structural equation modeling(PLS-SEM)is a modern multivariate analysis technique with a demonstrated ability to estimate theoretically established cause-effect relationship models.This technique has been increasingly adopted in construction management research over the last two decades.Accordingly,a critical review of studies adopting PLS-SEM appears to be a timely and valuable endeavor.This paper offers a critical review of 139 articles that applied PLS-SEM from 2002 to 2019.Results show that the misuse of PLS-SEM can be avoided.Critical issues related to the application of PLS-SEM,research design,model development,and model evaluation are discussed in detail.This paper is the first to highlight the use and misuse of PLS-SEM in the construction management area and provides recommendations to facilitate the future application of PLS-SEM in this field.
基金This work is supported by Chongqing Municipal Natural Science Foundation(Grant Nos.cstc2021jcyj-bsh0189 and cstc2019jcyj-bshX0070)Chongqing Jiulongpo District Science and Technology Planning Project(Grant No.2020-01-001-Y).
文摘Concrete exterior quality is one of the important metrics in evaluating construction project quality.Among the defects affecting concrete exterior quality,bughole is one of the most common imperfections,thus detecting concrete bughole accurately is significant for improving concrete exterior quality and consequently the quality of the whole project.This paper presents a deep learning-based method for detecting concrete surface bugholes in a more objective and automatic way.The bugholes are identified in concrete surface images by Mask R-CNN.An evaluation metric is developed to indicate the scale of concrete bughole.The proposed approach can detect bugholes in an instance level automatically and output the mask of each bughole,based on which the bughole area ratio is automatically calculated and the quality grade of the concrete surfaces is assessed.For demonstration,a total of 273 raw concrete surface images taken by mobile phone cameras are collected as a dataset.The test results show that the average precision(AP)of bughole masks is 90.8%.
基金This manuscript has been authored by an author at Lawrence Berkeley National Laboratory under Contract No.DE-AC02-05CH11231 with the U.S.Department of Energy
文摘Decarbonization in operational residential buildings worldwide has become critical in achieving the carbon neutral target due to the growing household energy demand.To accelerate the pace of global carbon neutrality,this study explores the operational carbon change in global residential buildings through the generalized Divisia index method and decoupling analysis,considering the decarbonization levels of residential buildings at different scales.The results show that(1)most of the samples showed a decrease in the total emissions from 2000 to 2019.Except for China and the United States(US),the carbon emissions in global residential building operations decreased by 7.95 million tons of carbon dioxide(MtCO_(2))per year over the study period.Emissions per gross domestic product(GDP)was the most positive driver causing the decarbonization of residential buildings,while GDP was the most negative driver.(2)Carbon intensity was essential to achieving a strong decoupling of economic development and carbon emissions.The US almost consistently presented strong decoupling,while China showed weak decoupling over the last two decades.(3)The pace of decarbonization in global residential building operations is gradually slowing down.From 2000 to 2019,decarbonization from residential buildings across 30 countries was 2094.3 MtCO_(2),with a decarbonization efficiency of 3.4%.Overall,this study addresses gaps in evaluating global decarbonization from operational residential buildings and provides a reference for evaluating building decarbonization by other emitters.
基金supported by the National Key R&D Program of China(No.2018YFD1100203)the National Natural Science Foundation of China(No.52200208)the International Postdoctoral Exchange Fellowship Program(No.YJ20200280)。
文摘Lessening energy-related carbon emissions has become a crucial measure to achieve Chinese carbon neutrality.This study is the first to construct a Difference in Carbon pressures-adjusted Human Development Index(DCHDI)model for the purpose of exploring the coupling effect between carbon emissions and human development variety from 2000 to 2019 in Chinese provinces.We demonstrate the following.(1)The total energy-related carbon footprint of 30 provinces in China reached 10.2 billion tons in 2019,with an average annual growth rate of 6.93% over the past two decades;and the provinces with the highest carbon emissions per capita are InnerMongolia,Ningxia,and Shanxi.(2)At the provincial level,we observed that the Human Development Index(HDI),which includes life expectancy,education,and income,has been rising,while Beijing,Shanghai,and Tianjin entered the super-high HDI level before 2008.(3)The entire coupling effect of 30 Chinese provinces has been broadly fortified in the last 20 years,but the growth rate of DCHDI values in 2011-2019 has slowed down compared with that in 2000-2010;the clustering phenomenon demonstrated that this discovery is associated with historical peaks in total carbon emissions.(4)The co-ordination degree of carbon emissions per capita and HDI was verified,and 96% of the data points were found in the range of super high coupling coordination degree.Overall,this study provides the government with worthwhile guidance for decision-making and carbon reduction strategies for other countries struggling to advance human sustainable development.
基金the National Key R&D Program of China(SQ2021YFC3200085)the National Natural Science Foundation of China(72022004)+1 种基金Chenyang Shuai thanks the support provided by the Fundamental Research Funds for the Central Universities(2022CDJSKJC21)Xi Chen thanks the support provided by Social Science Planning Project of Chongqing(2021BS069).
文摘The COvID-19 pandemic has posed severe threats to global sustainable development.However,a comprehensive quantitative assessment of the impacts of COVID-19 on Sustainable Development Goals(SDGs)is still lacking.This research quantified the post-COVID-19 SDG progress from 2020 to 2024 using projected GDP growth and population and machine learning models including support vector machine,random forest,and extreme gradient boosting.The results show that the overall SDG performance declined by 7.7%in 2020 at the global scale,with 12 socioeconomic SDG performance decreasing by 3.0%-22.3%and 4 environmental SDG performance increasing by 1.6%-9.2%.By 2024,the progress of 12 SDGs will lag behind for one to eight years compared to their pre-COVID-19 trajectories,while extra time will be gained for 4 environment-related SDGs.Furthermore,the pandemic will cause more impacts on countries in emerging markets and developing economies than those on advanced economies,and the latter will recover more quickly to be closer to their pre-covID-19 trajectories by 2024.Post-COVID-19 economic recovery should emphasize in areas that can help decouple economic growth from negative environmental impacts.The results can help government and non-state stakeholders identify critical areas for targeted policy to resume and speed up the progress to achieve SDGs by 2030.
基金supported by the National Natural Science Foundation of China(Grant No.61872050,No.62172066)the Chongqing Basic and Frontier Research Program(cste2018jcyjAX0551),the FundamentaRl esearchFundsforthe,Central Universityes(2018CDJSK03XK01)the Chongqing Technology Innovation and Application Development Key Project(ctsc2019jscx-gksbx0066)。
文摘Understanding the influencing mechanism of the urban streetscape on crime is fairly important to crime prevention and urban management.Recently,the development of deep learning technology and big data of street view images,makes it possible to quantitatively explore the relationship between streetscape and crime.This study computed eight streetscape indexes of the street built environment using Google Street View images firstly.Then,the association between the eight indexes and recorded crime events was revealed with a poisson regression model and a geographically weighted poisson regression model.An experiment was conducted in downtown and uptown Manhattan,New York.Global regression results show that the influences of Motorization Index on crimes are significant and positive,while the effects of the Light View Index and Green View Index on crimes depend heavily on the socioeconomic factors.From a local perspective,the Pedestrian Space Index,Green View Index,Light View Index and Motorization Index have a significant spatial influence on crimes,while the same visual streetscape factors have different effects on different streets due to the combination differences of socioeconomic,cultural and streetscape elements.The key streetscape elements of a given street that affect a specific criminal activity can be identified according to the strength of the association.The results provide both theoretical and practical implications for crime theories and crime prevention efforts.
基金Supported by General Projects of Talent Introduction Project in 2020 of Dalian University of Technology(DUT20RC(3)061)National Natural Science Foundation of China(71801024)National Key R&D Program of China(2018YFD1100203)。
文摘The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other industries. This paper utilizes the multi-regional input-output(MRIO)model to measure the embodied energy consumption in China's construction industry at the province level. To quantify the backward and forward linkages between the construction industry and other industries, the energy-driven and energy-driving abilities of the construction industry are investigated for 30 provinces. The results show that the values of the energy-driven coefficients are significantly larger than the energy-driving coefficients, indicating that the construction industry is highly dependent on products from other industries and other regions, not vice versa. The construction industries in the southwest and northwest regions of China have the highest energy-driven coefficients, showing that the construction industries in west China heavily rely on indirect energy embodied in goods and services. This particularly applies in Guangxi and Hainan provinces, which have the highest energydriven abilities and the lowest energy-driving abilities. The findings can facilitate the policy-makers to examine the critical energy-saving paths.
基金Supported by the National Key R&D Program of China(2018YFD1100203)the National Natural Science Foundation of China(71801024)Social Science Planning Project of Chongqing(2019QNGL30)
文摘Although China has made great achievements in economic scale,the model of high-quality economic developments is still in the exploratory stage.A series problems,such as unreasonable industrial structure and low production effciency,need to be resolved urgently.The transformation and upgrading of industrial structure is the inevitable choice.The analysis of industrial relations is an important method to reveal the internal mechanism of industrial structure change.Therefore,based on the concepts of sensitivity and influence coeffcient,this paper proposed the concepts of driven and driving coeffcient,and constructed the industrial complex networks of China from 1999 to 2013 according to the EORA input-output table.From the perspectives of the interaction power,industrial linkages and community structure,this paper systematically analyzes the evolution of China’s industrial structure.Results show that China’s industrial structure is undergoing a transformation from industry-oriented to industry-service-oriented.The interaction linkages between industries has formed a robust association structure.The traditional sectors such as infrastructure construction and industries are still the largest consumer group driving the development of other industries.Besides,light industry,infrastructure construction and finance have become increasingly important hub industries in the industrial system.However,some unbalanced community structures are formed in the economic system,which has resulted in a waste of resources and low production effciency to a certain extent.Effectively grasping the relationship between China’s industrial structure evolution and its association is conducive to formulating economic restructuring policies,promoting the upgrading of China’s economic and,realizing the leap from quantitative change to qualitative change.
文摘The arrival of the high-speed rail(HSR)era has accelerated the pace of urban development,but its broad socioeconomic impact remains subject to intense debates.This research aims to propose a model for measuring the impact of HSR operation on HSR stations and the surrounding areas,which this research call the HSR丒 based nodal zone(HNZ).The proposed model is composed of two variables(i.e.,transportation situation and vitality)and three subsystems(i.e.,economic,societal,and environmental).Data were collected in China through questionnaire survey.Results indicate that the effects of HSR operation on HNZ are multidimensional,transportation vitality has an intermediary role in the effects,and the effects on the physical environment are negative.This study presents an early examination of the impact of HSR operation on the HSR stations and relevant areas and contributes new evidence to academic debates on the contribution of HSR to urban development.Accordingly,urban development policies should be built on the mechanism of HSR in driving the growth of HNZ.
文摘Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various definitions of the urban built-up area and proposes three definition methods: all urban built-up areas in a municipal administrative area, concentrated contiguous built-up areas, and urban built-up areas in central cities. From the latest Landsat 8 satellite images, the paper obtains the data of urban built-up area in some of China’s big cities and makes a comparative study between the results of the urban built-up areas by the three definition methods and three other common statistical data. It finds that neither the area data nor the ranking is consistent. Finally, it further explores what causes differences in rankings and gives some advice for improving the definition of the urban built-up area.
基金financial support provided by Fundamental Research Funds for the Central Universities-China(No.2018CDJSK03XK15)project support by the National Planning Office of Philosophy and Social Science Foundation of China-China(No.18BJY06).
文摘The construction industry is one of the major producers of municipal solid waste.Although there are many studies in municipal solid waste management,the research on the recovery of recyclable building material from construction sites remains limited.This paper addresses the optimal design issue of the construction and demolition(C&D)waste logistics network based on the features of the construction industry from the contractors’perspective.The purpose of this paper is to provide an optimal C&D waste recycling network decision(RND)model considering the change of construction sites location over time.A multi-period and multi-objective mixed-integer linear programming model was developed to minimize the cost of C&D waste disposal for contractors,and to minimize the carbon emissions from C&D waste transportation.An application study was conducted to assess the performance of the RND model.Through some sensitivity analysis experiments based on an immune genetic algorithm,the influences of environmental policies and carbon tax policy on improving the recycling rate of C&D waste and reduce the carbon emission were explored.The findings of this research suggest that:(1)a RND model with the feature of the construction industry developed in this paper can effectively optimize the C&D waste logistics network;(2)government policies and laws are valid political instruments to improve the recycling rate of C&D waste;(3)the carbon-tax analyses demonstrate that a carbon tax policy can effectively reduce carbon emissions.
