This study examined the influence of the built environment surrounding rail stations on rail transit ridership and its spatiotemporal variations,aiming to enhance rail transit operational efficiency and inform station...This study examined the influence of the built environment surrounding rail stations on rail transit ridership and its spatiotemporal variations,aiming to enhance rail transit operational efficiency and inform station planning and development.Data from 159 metro stations in Nanjing,collected over a 14-d period,were analyzed to identify changes in weekday and weekend ridership patterns.The analysis included explanatory variables grouped into three categories:urban spatial variables,socioeconomic vari-ables,and transit service variables.A geographically and temporally weighted regression(GTWR)model was developed,and its performance was compared with that of ordinary least squares(OLS)and geographically weighted regression(GWR)models.The results demonstrated that the GTWR model outperformed others in analyzing the relationship between rail transit ridership and the built environment.In addition,the coefficients of explanatory variables showed significant variation across spatiotemporal dimensions,revealing distinct patterns.Notably,the influence of commuter flows led to more pronounced temporal heterogeneity in the coefficients observed on weekdays.These findings offer valuable insights for optimizing urban public transportation systems and advancing integrated urban rail development.展开更多
As globalization accelerates,microbial contamination in the built environment poses a major public health challenge.Especially since Corona Virus Disease 2019(COVID-19),microbial sterilization technology has become a ...As globalization accelerates,microbial contamination in the built environment poses a major public health challenge.Especially since Corona Virus Disease 2019(COVID-19),microbial sterilization technology has become a crucial research area for indoor air pollution control in order to create a hygienic and safe built environment.Based on this,the study reviews sterilization technologies in the built environment,focusing on the principles,efficiency and applicability,revealing advantages and limitations,and summarizing current research advances.Despite the efficacy of single sterilization technologies in specific environments,the corresponding side effects still exist.Thus,this review highlights the efficiency of hybrid sterilization technologies,providing an in-depth understanding of the practical application in the built environment.Also,it presents an outlook on the future direction of sterilization technology,including the development of new methods that are more efficient,energy-saving,and targeted to better address microbial contamination in the complex and changing built environment.Overall,this study provides a clear guide for selecting technologies to handle microbial contamination in different building environments in the future,as well as a scientific basis for developing more effective air quality control strategies.展开更多
Newly built tunnels often encounter a series of defects within the first few years of operation.If not promptly addressed and reinforced,these defects threaten the tunnel's durability and stability and bring sever...Newly built tunnels often encounter a series of defects within the first few years of operation.If not promptly addressed and reinforced,these defects threaten the tunnel's durability and stability and bring severe challenges to its safe operation.This study aims to explore reinforcement techniques for addressing defects in newly built tunnels.The research begins with an analysis of common defects found in newly built tunnels,followed by a case study of the Jinfeng Tunnel in Chongqing,examining the post-construction defects.The actual reinforcement strategies and methods employed for the tunnel are then discussed.Finally,based on the research findings,this study provides insights and references for tunnel operation and construction units in China,aiming to enhance the overall quality of tunnel engineering in the country,align with sustainable development goals,and promote further improvements at a macro level.展开更多
The effects of the built environment factors on urban vitality have attracted wide attention in the urban planning fields in recent years,but few studies have considered the variables’relative importance and their no...The effects of the built environment factors on urban vitality have attracted wide attention in the urban planning fields in recent years,but few studies have considered the variables’relative importance and their nonlinear effects on urban vitality.Taking a Chinese metropolis—Hangzhou as a case study,this study applied the gradient boosting decision tree(GBDT)model to explore the nonlinear effects of the 5D factors of the urban built environment on urban social vitality and economic vitality and the importance of variables.The results show that the GBDT model has better goodness of fit than the traditional ordinary least squares(OLS)regression in the urban vitality models.The urban built environment plays an important role in affecting urban vitality,while built environment designs witness the most important effect.Specifically,the density of shopping facilities,medical facilities,and road networks are the most important factors affecting urban social vitality,while road network density,destination accessibility,and population density play the most important roles in affecting urban economic vitality.Finally,the urban built environment factors have nonlinear threshold effects on both urban economic and social vitality in Hangzhou,with differing nonlinear response patterns observed between social and economic dimensions.展开更多
Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relation...Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relationship between land values and the five built environment dimensions using machine learning algorithms and Shapley Additive ex Planation(SHAP).The results highlight that the Gradient Boost Decision Tree (GBDT) outperforms e Xtreme Gradient Boosting (XGBoost),Ordinary Least Squares (OLS),and Multiscale Geographically Weighted Regression (MGWR) in land value estimation,exhibiting higher R^(2) and lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE).The results illustrate that density and destination accessibility are the dominant factors,contributing 32.48%and37.38%to land value variation,respectively.We observed that the top three factors affecting land values are the built-floor area ratio,the number of floors and the number of restaurants.Additionally,the results revealed the non-linear relationship between the built environment and land values,suggesting that maintaining built environment features at optimal thresholds may increase land values.Neglecting interaction effects may lead to bias in determining relationships between land values and the built environment.This study contributes to the literature by providing non-linear and threshold identification evidence in land value determinants,offering valuable insights for urban planners and real estate managers.展开更多
In China,numerous cities are expanding into sloping land,yet the quantitative distribution patterns of urban built-up land density along the slope gradient remain unclear,limiting the understanding of sloping land urb...In China,numerous cities are expanding into sloping land,yet the quantitative distribution patterns of urban built-up land density along the slope gradient remain unclear,limiting the understanding of sloping land urbanization.In this paper,a simple negative exponential function was presented to verify its applicability in 19 typical sloping urban areas in China.The function fits well for all case urban areas(R^(2)≥0.951,p<0.001).The parameters of this function clearly describe two fundamental attributes:initial value a and decline rate b.Between 2000 and 2020,a tends to increase,while b tends to decrease in all urban areas,confirming the hypothesis of mutual promotion between flatland densification and sloping land expansion.Multiple regression analysis indicates that the built-up land density and the ruggedness of background land can explain 70.7%of a,while the average slope ratio of built-up land to background land,the built-up land density and the built-up land area can explain 82.1%of b.This work provides a quantitative investigative tool for distribution of urban built-up land density along slope gradient,aiding in the study of the globally increasing phenomenon of sloping land urbanization from a new perspective.展开更多
China is experiencing rapid population aging.The one contributing factor affecting senior citizens’lives is the disconnect between the built environment in urban and rural areas and the behavioral preferences of olde...China is experiencing rapid population aging.The one contributing factor affecting senior citizens’lives is the disconnect between the built environment in urban and rural areas and the behavioral preferences of older adults.However,research on the relation between the built environment and the behavior of older individuals has been limited.Thus,this paper uses the most recent health tracking data on factors influencing aging in China released in 2020(China Senior Health Survey Tracking Survey).Applying traditional regression,least absolute shrinkage and selection operator regression,and two decision tree optimization models from machine learning,a comprehensive comparative study is carried out to investigate the correlation between the built environment and the physical activity,dietary habits,and social interactions of older age groups.The findings reveal that built environment variables most significantly impact physical activity,accounting for 52.525%,followed by social interaction behaviors at 50.202%and dietary intake at 47.991%.Furthermore,the authors identify population density and greenness rate as the built environment factors having considerable effects on the behavior of older adults.Thus,this study establishes a theoretical foundation for developing age-friendly community environments for older adults.展开更多
The aim of this study was to carry out a dynamic simulation of the energy and environmental performance of a built space system, with a view to assessing its energy and environmental class. The use of a simulation and...The aim of this study was to carry out a dynamic simulation of the energy and environmental performance of a built space system, with a view to assessing its energy and environmental class. The use of a simulation and modeling tool, supported by various methodological references, formed the basis of our approach. Adopting a systemic perspective, we described the structural and functional aspects of the systems making up built spaces, as well as the associated energy flows. Our approach was also based on a typology, taking into account typical days, structural and functional configurations at different scales and angles of observation. The analysis tool we developed in Java was applied to the built space system of the Patte d’Oie university campus in Ouagadougou. Annual electricity consumption was measured at 124387.34 kWh, closely aligned with the average annual electricity bill (125224.31 kWh), with a maximum relative deviation of 1%, followed by a carbon emission balance of 58337.66 kg eq CO<sub>2</sub> per year. This validation confirmed the effectiveness of our tool. In addition, following the analysis of electricity consumption using our tool, the university campus was classified in energy class B and environmental class C. These results will be based on the emission factors of the energy mix of the West African Economic and Monetary Union (WAEMU) territory, with particular emphasis on Burkina Faso.展开更多
Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried ...Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried out.However,the impact of built environment on traffic crash spatiotemporal trends has not received much attention.Moreover,the spatial non-stationarity between the variation trends of traffic crashes and their influencing factors is usually neglected.To make up for the lack of analysis of built environment factors influencing spatiotemporal hotspot trends in traffic crashes,this paper proposed a method of“ST-GWLR”for analyzing the influence of built environment factors on spatiotemporal hotspot trends of traffic crashes by combining the spatiotemporal hotspot trend analysis and Geographically Weighted Logistic Regression(GWLR)modeling methods.Firstly,the traffic crash spatiotemporal hotspot trends were explored using the space-time cube model,hotspot analysis,and Mann-Kendall trend test.Then,the GWLR was introduced to capture the spatial non-stationarity neglected by the classic Global Logistic Regression(GLR)model,to improve the accuracy of the model estimation.GWLR model is used for the first time to analyze the significant local correlation between the traffic crash spatiotemporal hotspot trends and the built environment factors,to accurately and effectively identify the built environment factors that have significant influences on the hotspot trends of traffic crashes.The performance of the GWLR models and GLR models was examined and compared sufficiently.The results showed that the proposed ST-GWLR,which captured spatial non-stationarity,performed better than the classic GLR combined with spatiotemporal analysis,and improved the prediction accuracy of the models by 14.9%,13.9%,and 15.1%,respectively.There were significant local correlations between intensifying hotspots and persistent hotspots of traffic crashes and the built environment factors.The findings of this paper have positive implications for traffic safety management and urban built environment planning.展开更多
With the global economy increasingly dependent on innovation,urban discourse has shifted to consider what kinds of spatial designs may best nurture innovation.We examined the relationship between the built environment...With the global economy increasingly dependent on innovation,urban discourse has shifted to consider what kinds of spatial designs may best nurture innovation.We examined the relationship between the built environment and the spatial heterogeneity of regional innovation productivity(RIP)using the example of China's Pearl River Delta(PRD).Based on a spatial database of 522546 patent data from 2017,this study proposed an innovation-based built environment framework with the following five aspects:healthy en-vironment,daily interaction,mixed land use,commuting convenience,and technology atmosphere.Combining negative binomial regression and Geodetector to examine the impact of the built environment on RIP,the results show that the spatial distribution of innovation productivity in the PRD region is extremely uneven.The negative binomial regression results show that the built environment has a significant impact on the spatial differentiation of RIP,and,specifically,that healthy environment,mixed land use,commuting convenience,and technology atmosphere all demonstrate significant positive impacts.Meanwhile,the Geodetector results show that the built environment factor impacts the spatial heterogeneity of RIP to varying degrees,with technology atmosphere demonstrating the greatest impact intensity.We conclude that as regional development discourse shifts focus to the knowledge and innovation economy,the innovation-oriented design and updating of built environments will become extremely important to policymakers.展开更多
This study applies multi-source datasets(i.e.,Baidu Heat Map data,points of interest(POIs)data,and floor area and land use data)and geographically and temporally weighted regression(GTWR)models to elaborate the spatio...This study applies multi-source datasets(i.e.,Baidu Heat Map data,points of interest(POIs)data,and floor area and land use data)and geographically and temporally weighted regression(GTWR)models to elaborate the spatiotemporal relationships between the built environment and urban vibrancy on both weekdays and weekends,using Guangzhou City as a case.First,we verified the spatially and temporally nonstationary nature of the built environment correlates,which have been largely ignored in previous studies based on local regression techniques.The spatially and temporally heterogeneous effects of the built environment on urban vibrancy are then presented and visualized,based on the GTWR results.We found that the elasticity of location(i.e.,distance),land use mix(i.e.,diversity),building intensity and numbers of POIs with various functions(i.e.,density)are different across time(2-h intervals within a day)and space(grids),due to people’s everyday lifestyle,time-space constraints,and geographical context(e.g.,spatial structure).The findings highlight the importance of a better understanding of the local geography on the spatiotemporal relationships for urban planners and local governments so as to put forward decision-making support for fostering and maintaining urban vibrancy.展开更多
Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the sc...Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the scale were determined based on a review of policy documents and consultations with experts. The final items of the scale were confirmed through individual interviews with residents combined with the discretetrend method, critical ratio method, correlation coefficient method, and factor analysis method. Then, the dimensions of the scale were determined using exploratory factor analysis(EFA). The Cronbach’s α coefficient, split-half reliability coefficient, and confirmatory factor analysis(CFA) were used to assess the reliability and validity of the scale.Results A scale containing five dimensions with 22 items was established, including urban lifestyle,governance, basic functions, environmental sanitation, and amenities. The Cronbach’s α coefficient of the scale was 0.876, and the split-half reliability coefficient was 0.796. The CFA results indicate that each inspection level was within the standard limit.Conclusion The preliminarily subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative demonstrates a high level of reliability and validity. Additional empirical studies should be carried out to further verify the value of the scale in terms of practical application.展开更多
China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteri...China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteristics and differences in built-up area for China＇s MFOZs using a China＇ s Land Use Database （CLUD） derived from high-resolution remotely sensed images in the periods of 2000-2010 and 2010-2013. To sum up： （1） The percentage of built-up area in each of the MFOZs was significantly different, revealing the gradient feature of national land development based on the distribution of the main functions. （2） Annual growth in built-up area in optimal development zones （ODZs） decreased signifi- cantly during 2010-2013 compared with the period 2000-2010, while annual growth in built-up area in key development zones （KDZs）, agricultural production zones （APZs） and key ecological function zones （KEFZs） increased significantly. （3） In ODZs, the average annual increase in built-up area in the Yangtze River Delta region was significantly higher than in other regions; the average area increase and rate of increase of built-up area in KDZs was faster in the western region than in other regions; average annual area growth of built-up area in APZs in the northeast, central and western regions was twice as high as the previous decade on average; the annual rate of change and increase in the dynamic degree of built-up area were most notable in KEFZs in the central region. （4） The spatial pattern and charac- teristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for MFOZs. But the rate of increase locally in built-up area in ODZs, APZs and KEFZs is fast, so the effective measures must be adopted in the implementation of national and regional policies. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.展开更多
An experimental program was initiated to investigate the seismic performance of built-up laced steel brace members. Quasi-static testing of twelve typical steel built-up laced member （BLM） specimens was conducted. T...An experimental program was initiated to investigate the seismic performance of built-up laced steel brace members. Quasi-static testing of twelve typical steel built-up laced member （BLM） specimens was conducted. These were designed to span a range of parameters typically encountered for such members based on findings from a survey of commonly used shapes and details that have been historically used. The specimens were subdivided into groups of three different cross-sectional shapes, namely built-up I-shape section, and built-up box shapes buckling about the x or the y axis. Within each group, global and local buckling slenderness ratios had either kl/r values of 60 or 120, and b/t ratios of 8 or 16. The specific inelastic cyclic behavior germane to each specimen, and general observations on overall member hysteretic behavior as a function of the considered parameters, are reported. A companion paper （Lee and Bruneau 2008） investigates this observed response against predictions from analytical models, and behavior in the perspective of system performance.展开更多
Background: Built environments that are designed to provide accessible, attractive, and convenient locales promote regular physical activity(PA).Norway has great variability in its geographic, natural, and built envir...Background: Built environments that are designed to provide accessible, attractive, and convenient locales promote regular physical activity(PA).Norway has great variability in its geographic, natural, and built environment features. Urban areas have well-developed built environment features, whereas the rural areas are less walkable and this may influence the mode of transport. In general, active transport is more common in urban centers. Further, public transportation is more developed in urban areas, whereas motorized transport may be more widespread in the rural areas. Despite this, in Sogn & Fjordane, a rural county in western Norway, high PA levels are frequently observed. Thus, the aims of this study were to(1) explore perceived built environment features and characterize their associations with objectively measured PA levels in Norwegian adults and(2) explore the differences in these correlates between Sogn & Fjordane and the rest of Norway.Methods: In this cross-sectional study, participants used questionnaires to rate perceptions of their built environments, and their PA was objectively measured for 7 consecutive days using the Acti Graph GT1 M accelerometer. There were 972 Norwegian adults who were included in the study. The average age was 46.9 ± 6.5 years and 43.8% of participants were men. Data were analyzed using multiple linear regression.Results: Total PA and moderate-to-vigorous physical activity(MVPA) were both associated with perceived walkability, the community perception score, and active transport for commuting(all p ≤ 0.004). We also observed geographic-area-specific associations: the community perception score was negatively associated with total PA and MVPA in the rest of Norway(p ≤ 0.012) but not in Sogn & Fjordane. Public transport for commuting was positively associated with MVPA in Sogn & Fjordane(p = 0.03) but not in the rest of Norway.Conclusion: Total PA level and MVPA were associated with built environment factors, such as perceptions of community, perceived walkability,and engaging in active transport for commuting. Geographic differences in the PA correlates were observed, and thus, locally customized environmental population approaches aimed at increasing PA levels may be essential complements to individual behavior and lifestyle strategies.Further, objective measures of Norwegian built environments, such as geographic information system data, and validated walk-and bike-scores would advance the field.展开更多
Comparative study of LUCC between Fujian and Taiwan provinces could be a good case for study because of their geographical proximities and historical, cultural similarities. Fujian and Taiwan had gone through and curr...Comparative study of LUCC between Fujian and Taiwan provinces could be a good case for study because of their geographical proximities and historical, cultural similarities. Fujian and Taiwan had gone through and currently are in different economic development stages. Taiwan is in the stage of post-industrialization and Fujian is in the intermediate stage of industrialization. By using the official statistics, changes of built-land in Fujian and Taiwan were analyzed in details. The results showed that these two provinces seemed to have the same characteristics of built-land changes, i.e., accelerating development, and concentrated distribution on both sides of the Taiwan Straits, forming a pattern with the economic layout of two sides acting in cooperation with eath other. If comparing different industrialized areas in Fujian with industrialized stages in Taiwan, it is clear that these two provinces seemed to have the same characteristics of synthesized index of built-land change （Lc）, i.e., which is from stabilization or comparative stabilization at the initial stages of industrialization to high expansion at the intermediate stages of industrialization, then followed by low consumption at later stages of industrialization, but the Lc of the initial and the later stages of industrialization in Taiwan were slightly higher than those in Fujian. The results from comparison on relevant indexes have shown： The industrial structure changing rate of Fujian is actually higher than that of built-land in Taiwan, but its using efficiency of regional built-land is also obviously lower than that in Taiwan in the intermediate and later stages of industrialization of Fujian. The major driving forces of the built-land changes in both provinces were analyzed in Causal Models of Path Analysis, and its result indicated that the difference in built-land changes of the two provinces is closely related to their economic development stages and industrial structure. Countermeasure for the realization of sustainable utilization of built-land in Fujian put forward in this article is to strengthen its intension and tap the latent power.展开更多
The cyclotron mass of magnetopolarons in wurtzite InxGa1-xN/GaN quantum well is studied in the presence of an external magnetic field by using the Larsen perturbation method. The effects of the built-in electric field...The cyclotron mass of magnetopolarons in wurtzite InxGa1-xN/GaN quantum well is studied in the presence of an external magnetic field by using the Larsen perturbation method. The effects of the built-in electric field and different phonon modes including interface, confined and half-space phonon modes are considered in our calculation. The results for a zinc-blende quantum well are also given for comparison. It is found that the main contribution to the transition energy comes from half-space and interface phonon modes when the well width is very small while the confined modes play a more important role in a wider well due to the location of the electron wave function. As the well width increases, the cyclotron mass of magnetopolarons first increases to a maximum and then decreases either with or without the built-in electric field in the wurtzite structure and the built-in electric field slightly reduces the cyclotron mass. The variation of cyclotron mass in a zinc-blende structure is similar to that in a wurtzite structure. With the increase of external magnetic field, the cyclotron mass of polarons almost linearly increases. The cyclotron frequency of magnetopolarons is also discussed.展开更多
The Tourism Bureau of Heilongjiang Province announces that a paleontological museum devoted to Quaternary fossil mammoths has been built in Qinggang County in that province. This museum, recently olticially opened, ca...The Tourism Bureau of Heilongjiang Province announces that a paleontological museum devoted to Quaternary fossil mammoths has been built in Qinggang County in that province. This museum, recently olticially opened, can be used to exhibit collections and conduct popular science education as well as scientific research （Fig. 1）.展开更多
As-built building information model （BIM） is an urgent need of the architecture, engineering, construction and facilities management （AEC/FM） community. However, its creation procedure is still labor-intensive and...As-built building information model （BIM） is an urgent need of the architecture, engineering, construction and facilities management （AEC/FM） community. However, its creation procedure is still labor-intensive and far from maturity. Taking advantage of prevalence of digital cameras and the development of advanced computer vision technology, the paper proposes to reconstruct a building facade and recognize its surface materials from images taken from various points of view. These can serve as initial steps towards automatic generation of as-built BIM. Specifically, 3D point clouds are generated from multiple images using structure from motion method and then segmented into planar components, which are further recognized as different structural components through knowledge based reasoning. Windows are detected through a multilayered complementary strategy by combining detection results from every semantic layer. A novel machine learning based 3D material recognition strategy is presented. Binary classifiers are trained through support vector machines. Material type at a given 3D location is predicted by all its corresponding 2D feature points. Experimental results from three existing buildings validate the proposed system.展开更多
基金The National Key Research and Development Program of China(No.2022YFC3800201).
文摘This study examined the influence of the built environment surrounding rail stations on rail transit ridership and its spatiotemporal variations,aiming to enhance rail transit operational efficiency and inform station planning and development.Data from 159 metro stations in Nanjing,collected over a 14-d period,were analyzed to identify changes in weekday and weekend ridership patterns.The analysis included explanatory variables grouped into three categories:urban spatial variables,socioeconomic vari-ables,and transit service variables.A geographically and temporally weighted regression(GTWR)model was developed,and its performance was compared with that of ordinary least squares(OLS)and geographically weighted regression(GWR)models.The results demonstrated that the GTWR model outperformed others in analyzing the relationship between rail transit ridership and the built environment.In addition,the coefficients of explanatory variables showed significant variation across spatiotemporal dimensions,revealing distinct patterns.Notably,the influence of commuter flows led to more pronounced temporal heterogeneity in the coefficients observed on weekdays.These findings offer valuable insights for optimizing urban public transportation systems and advancing integrated urban rail development.
文摘As globalization accelerates,microbial contamination in the built environment poses a major public health challenge.Especially since Corona Virus Disease 2019(COVID-19),microbial sterilization technology has become a crucial research area for indoor air pollution control in order to create a hygienic and safe built environment.Based on this,the study reviews sterilization technologies in the built environment,focusing on the principles,efficiency and applicability,revealing advantages and limitations,and summarizing current research advances.Despite the efficacy of single sterilization technologies in specific environments,the corresponding side effects still exist.Thus,this review highlights the efficiency of hybrid sterilization technologies,providing an in-depth understanding of the practical application in the built environment.Also,it presents an outlook on the future direction of sterilization technology,including the development of new methods that are more efficient,energy-saving,and targeted to better address microbial contamination in the complex and changing built environment.Overall,this study provides a clear guide for selecting technologies to handle microbial contamination in different building environments in the future,as well as a scientific basis for developing more effective air quality control strategies.
文摘Newly built tunnels often encounter a series of defects within the first few years of operation.If not promptly addressed and reinforced,these defects threaten the tunnel's durability and stability and bring severe challenges to its safe operation.This study aims to explore reinforcement techniques for addressing defects in newly built tunnels.The research begins with an analysis of common defects found in newly built tunnels,followed by a case study of the Jinfeng Tunnel in Chongqing,examining the post-construction defects.The actual reinforcement strategies and methods employed for the tunnel are then discussed.Finally,based on the research findings,this study provides insights and references for tunnel operation and construction units in China,aiming to enhance the overall quality of tunnel engineering in the country,align with sustainable development goals,and promote further improvements at a macro level.
基金National Social Science Foundation of China,No.20FJLB025National Natural Science Foundation of China,No.42471207,No.42471203Zhejiang Province Philosophy and Social Science Planning,Zhijiang Youth Special Project,24ZJQN118Y。
文摘The effects of the built environment factors on urban vitality have attracted wide attention in the urban planning fields in recent years,but few studies have considered the variables’relative importance and their nonlinear effects on urban vitality.Taking a Chinese metropolis—Hangzhou as a case study,this study applied the gradient boosting decision tree(GBDT)model to explore the nonlinear effects of the 5D factors of the urban built environment on urban social vitality and economic vitality and the importance of variables.The results show that the GBDT model has better goodness of fit than the traditional ordinary least squares(OLS)regression in the urban vitality models.The urban built environment plays an important role in affecting urban vitality,while built environment designs witness the most important effect.Specifically,the density of shopping facilities,medical facilities,and road networks are the most important factors affecting urban social vitality,while road network density,destination accessibility,and population density play the most important roles in affecting urban economic vitality.Finally,the urban built environment factors have nonlinear threshold effects on both urban economic and social vitality in Hangzhou,with differing nonlinear response patterns observed between social and economic dimensions.
文摘Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relationship between land values and the five built environment dimensions using machine learning algorithms and Shapley Additive ex Planation(SHAP).The results highlight that the Gradient Boost Decision Tree (GBDT) outperforms e Xtreme Gradient Boosting (XGBoost),Ordinary Least Squares (OLS),and Multiscale Geographically Weighted Regression (MGWR) in land value estimation,exhibiting higher R^(2) and lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE).The results illustrate that density and destination accessibility are the dominant factors,contributing 32.48%and37.38%to land value variation,respectively.We observed that the top three factors affecting land values are the built-floor area ratio,the number of floors and the number of restaurants.Additionally,the results revealed the non-linear relationship between the built environment and land values,suggesting that maintaining built environment features at optimal thresholds may increase land values.Neglecting interaction effects may lead to bias in determining relationships between land values and the built environment.This study contributes to the literature by providing non-linear and threshold identification evidence in land value determinants,offering valuable insights for urban planners and real estate managers.
基金supported by the project of the National Natural Science Foundation of China entitled“Distribution and change characteristics of construction land on slope gradient in mountainous cities of southern China”(No.41961039).
文摘In China,numerous cities are expanding into sloping land,yet the quantitative distribution patterns of urban built-up land density along the slope gradient remain unclear,limiting the understanding of sloping land urbanization.In this paper,a simple negative exponential function was presented to verify its applicability in 19 typical sloping urban areas in China.The function fits well for all case urban areas(R^(2)≥0.951,p<0.001).The parameters of this function clearly describe two fundamental attributes:initial value a and decline rate b.Between 2000 and 2020,a tends to increase,while b tends to decrease in all urban areas,confirming the hypothesis of mutual promotion between flatland densification and sloping land expansion.Multiple regression analysis indicates that the built-up land density and the ruggedness of background land can explain 70.7%of a,while the average slope ratio of built-up land to background land,the built-up land density and the built-up land area can explain 82.1%of b.This work provides a quantitative investigative tool for distribution of urban built-up land density along slope gradient,aiding in the study of the globally increasing phenomenon of sloping land urbanization from a new perspective.
基金supported by the Special Funds for Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds)[Grant No.pdjh2024a053]National Innovation and Entrepreneurship Training Program for Undergraduate[Grant No.S202310559083].
文摘China is experiencing rapid population aging.The one contributing factor affecting senior citizens’lives is the disconnect between the built environment in urban and rural areas and the behavioral preferences of older adults.However,research on the relation between the built environment and the behavior of older individuals has been limited.Thus,this paper uses the most recent health tracking data on factors influencing aging in China released in 2020(China Senior Health Survey Tracking Survey).Applying traditional regression,least absolute shrinkage and selection operator regression,and two decision tree optimization models from machine learning,a comprehensive comparative study is carried out to investigate the correlation between the built environment and the physical activity,dietary habits,and social interactions of older age groups.The findings reveal that built environment variables most significantly impact physical activity,accounting for 52.525%,followed by social interaction behaviors at 50.202%and dietary intake at 47.991%.Furthermore,the authors identify population density and greenness rate as the built environment factors having considerable effects on the behavior of older adults.Thus,this study establishes a theoretical foundation for developing age-friendly community environments for older adults.
文摘The aim of this study was to carry out a dynamic simulation of the energy and environmental performance of a built space system, with a view to assessing its energy and environmental class. The use of a simulation and modeling tool, supported by various methodological references, formed the basis of our approach. Adopting a systemic perspective, we described the structural and functional aspects of the systems making up built spaces, as well as the associated energy flows. Our approach was also based on a typology, taking into account typical days, structural and functional configurations at different scales and angles of observation. The analysis tool we developed in Java was applied to the built space system of the Patte d’Oie university campus in Ouagadougou. Annual electricity consumption was measured at 124387.34 kWh, closely aligned with the average annual electricity bill (125224.31 kWh), with a maximum relative deviation of 1%, followed by a carbon emission balance of 58337.66 kg eq CO<sub>2</sub> per year. This validation confirmed the effectiveness of our tool. In addition, following the analysis of electricity consumption using our tool, the university campus was classified in energy class B and environmental class C. These results will be based on the emission factors of the energy mix of the West African Economic and Monetary Union (WAEMU) territory, with particular emphasis on Burkina Faso.
基金supported by the National Natural Science Foundation of China[grant numbers 42101449,42090012 and 61825103]the Natural Science Foundation of Hubei Province,China[grant numbers 2022CFB773 and 2020CFA001]+2 种基金the Key Research and Development Program of Hubei Province,China[grant number 2022BAA048]the Chutian Scholar Program of Hubei Provincethe Yellow Crane Talent Scheme.
文摘Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried out.However,the impact of built environment on traffic crash spatiotemporal trends has not received much attention.Moreover,the spatial non-stationarity between the variation trends of traffic crashes and their influencing factors is usually neglected.To make up for the lack of analysis of built environment factors influencing spatiotemporal hotspot trends in traffic crashes,this paper proposed a method of“ST-GWLR”for analyzing the influence of built environment factors on spatiotemporal hotspot trends of traffic crashes by combining the spatiotemporal hotspot trend analysis and Geographically Weighted Logistic Regression(GWLR)modeling methods.Firstly,the traffic crash spatiotemporal hotspot trends were explored using the space-time cube model,hotspot analysis,and Mann-Kendall trend test.Then,the GWLR was introduced to capture the spatial non-stationarity neglected by the classic Global Logistic Regression(GLR)model,to improve the accuracy of the model estimation.GWLR model is used for the first time to analyze the significant local correlation between the traffic crash spatiotemporal hotspot trends and the built environment factors,to accurately and effectively identify the built environment factors that have significant influences on the hotspot trends of traffic crashes.The performance of the GWLR models and GLR models was examined and compared sufficiently.The results showed that the proposed ST-GWLR,which captured spatial non-stationarity,performed better than the classic GLR combined with spatiotemporal analysis,and improved the prediction accuracy of the models by 14.9%,13.9%,and 15.1%,respectively.There were significant local correlations between intensifying hotspots and persistent hotspots of traffic crashes and the built environment factors.The findings of this paper have positive implications for traffic safety management and urban built environment planning.
基金Under the auspices of National Natural Science Foundation of China(No.41871150)GDAS7 Project of Science and Technology Development(No.2021GDASYL-20210103004)+2 种基金National Key Research and Development Program(No.2019YFB2103-101)Special Construction Project of Guangdong-Hong Kong-Macao Greater Bay Area Strategic Research Institute(No.2020GDA-SYL-20200201001)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0301)。
文摘With the global economy increasingly dependent on innovation,urban discourse has shifted to consider what kinds of spatial designs may best nurture innovation.We examined the relationship between the built environment and the spatial heterogeneity of regional innovation productivity(RIP)using the example of China's Pearl River Delta(PRD).Based on a spatial database of 522546 patent data from 2017,this study proposed an innovation-based built environment framework with the following five aspects:healthy en-vironment,daily interaction,mixed land use,commuting convenience,and technology atmosphere.Combining negative binomial regression and Geodetector to examine the impact of the built environment on RIP,the results show that the spatial distribution of innovation productivity in the PRD region is extremely uneven.The negative binomial regression results show that the built environment has a significant impact on the spatial differentiation of RIP,and,specifically,that healthy environment,mixed land use,commuting convenience,and technology atmosphere all demonstrate significant positive impacts.Meanwhile,the Geodetector results show that the built environment factor impacts the spatial heterogeneity of RIP to varying degrees,with technology atmosphere demonstrating the greatest impact intensity.We conclude that as regional development discourse shifts focus to the knowledge and innovation economy,the innovation-oriented design and updating of built environments will become extremely important to policymakers.
基金Under the auspices of National Natural Science Foundation of China(No.41901191,41930646)Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.311020017)。
文摘This study applies multi-source datasets(i.e.,Baidu Heat Map data,points of interest(POIs)data,and floor area and land use data)and geographically and temporally weighted regression(GTWR)models to elaborate the spatiotemporal relationships between the built environment and urban vibrancy on both weekdays and weekends,using Guangzhou City as a case.First,we verified the spatially and temporally nonstationary nature of the built environment correlates,which have been largely ignored in previous studies based on local regression techniques.The spatially and temporally heterogeneous effects of the built environment on urban vibrancy are then presented and visualized,based on the GTWR results.We found that the elasticity of location(i.e.,distance),land use mix(i.e.,diversity),building intensity and numbers of POIs with various functions(i.e.,density)are different across time(2-h intervals within a day)and space(grids),due to people’s everyday lifestyle,time-space constraints,and geographical context(e.g.,spatial structure).The findings highlight the importance of a better understanding of the local geography on the spatiotemporal relationships for urban planners and local governments so as to put forward decision-making support for fostering and maintaining urban vibrancy.
基金supported by Operation Project of Public Health Emergency Response Mechanism of Chinese Center for Disease Control and Prevention [131031001000150001]FIDELIS-Hubei Program [No. 2004-fid-4-034]。
文摘Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the scale were determined based on a review of policy documents and consultations with experts. The final items of the scale were confirmed through individual interviews with residents combined with the discretetrend method, critical ratio method, correlation coefficient method, and factor analysis method. Then, the dimensions of the scale were determined using exploratory factor analysis(EFA). The Cronbach’s α coefficient, split-half reliability coefficient, and confirmatory factor analysis(CFA) were used to assess the reliability and validity of the scale.Results A scale containing five dimensions with 22 items was established, including urban lifestyle,governance, basic functions, environmental sanitation, and amenities. The Cronbach’s α coefficient of the scale was 0.876, and the split-half reliability coefficient was 0.796. The CFA results indicate that each inspection level was within the standard limit.Conclusion The preliminarily subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative demonstrates a high level of reliability and validity. Additional empirical studies should be carried out to further verify the value of the scale in terms of practical application.
基金Key Project of National Natural Science Foundation of China, No.41371409 National Key Technology R＆D Program, No.2013BAC03B00
文摘China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteristics and differences in built-up area for China＇s MFOZs using a China＇ s Land Use Database （CLUD） derived from high-resolution remotely sensed images in the periods of 2000-2010 and 2010-2013. To sum up： （1） The percentage of built-up area in each of the MFOZs was significantly different, revealing the gradient feature of national land development based on the distribution of the main functions. （2） Annual growth in built-up area in optimal development zones （ODZs） decreased signifi- cantly during 2010-2013 compared with the period 2000-2010, while annual growth in built-up area in key development zones （KDZs）, agricultural production zones （APZs） and key ecological function zones （KEFZs） increased significantly. （3） In ODZs, the average annual increase in built-up area in the Yangtze River Delta region was significantly higher than in other regions; the average area increase and rate of increase of built-up area in KDZs was faster in the western region than in other regions; average annual area growth of built-up area in APZs in the northeast, central and western regions was twice as high as the previous decade on average; the annual rate of change and increase in the dynamic degree of built-up area were most notable in KEFZs in the central region. （4） The spatial pattern and charac- teristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for MFOZs. But the rate of increase locally in built-up area in ODZs, APZs and KEFZs is fast, so the effective measures must be adopted in the implementation of national and regional policies. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.
基金Federal Highway Administration Under Grant No. DTFH61-98-C-00094
文摘An experimental program was initiated to investigate the seismic performance of built-up laced steel brace members. Quasi-static testing of twelve typical steel built-up laced member （BLM） specimens was conducted. These were designed to span a range of parameters typically encountered for such members based on findings from a survey of commonly used shapes and details that have been historically used. The specimens were subdivided into groups of three different cross-sectional shapes, namely built-up I-shape section, and built-up box shapes buckling about the x or the y axis. Within each group, global and local buckling slenderness ratios had either kl/r values of 60 or 120, and b/t ratios of 8 or 16. The specific inelastic cyclic behavior germane to each specimen, and general observations on overall member hysteretic behavior as a function of the considered parameters, are reported. A companion paper （Lee and Bruneau 2008） investigates this observed response against predictions from analytical models, and behavior in the perspective of system performance.
基金supported by the Sogn & Fjordane County Council, Sparebanken Vest–Visjon Vest, the Norwegian Directorate of Health, Norwegian School of Sport Sciences, and Sogn & Fjordane University College
文摘Background: Built environments that are designed to provide accessible, attractive, and convenient locales promote regular physical activity(PA).Norway has great variability in its geographic, natural, and built environment features. Urban areas have well-developed built environment features, whereas the rural areas are less walkable and this may influence the mode of transport. In general, active transport is more common in urban centers. Further, public transportation is more developed in urban areas, whereas motorized transport may be more widespread in the rural areas. Despite this, in Sogn & Fjordane, a rural county in western Norway, high PA levels are frequently observed. Thus, the aims of this study were to(1) explore perceived built environment features and characterize their associations with objectively measured PA levels in Norwegian adults and(2) explore the differences in these correlates between Sogn & Fjordane and the rest of Norway.Methods: In this cross-sectional study, participants used questionnaires to rate perceptions of their built environments, and their PA was objectively measured for 7 consecutive days using the Acti Graph GT1 M accelerometer. There were 972 Norwegian adults who were included in the study. The average age was 46.9 ± 6.5 years and 43.8% of participants were men. Data were analyzed using multiple linear regression.Results: Total PA and moderate-to-vigorous physical activity(MVPA) were both associated with perceived walkability, the community perception score, and active transport for commuting(all p ≤ 0.004). We also observed geographic-area-specific associations: the community perception score was negatively associated with total PA and MVPA in the rest of Norway(p ≤ 0.012) but not in Sogn & Fjordane. Public transport for commuting was positively associated with MVPA in Sogn & Fjordane(p = 0.03) but not in the rest of Norway.Conclusion: Total PA level and MVPA were associated with built environment factors, such as perceptions of community, perceived walkability,and engaging in active transport for commuting. Geographic differences in the PA correlates were observed, and thus, locally customized environmental population approaches aimed at increasing PA levels may be essential complements to individual behavior and lifestyle strategies.Further, objective measures of Norwegian built environments, such as geographic information system data, and validated walk-and bike-scores would advance the field.
基金National Natural Science Foundation of China, No.40371054Fujian Provincial Project, No.D0510014In-novative construction on resources and environment of the Economic Zone on the West Side of the Taiwan Straits
文摘Comparative study of LUCC between Fujian and Taiwan provinces could be a good case for study because of their geographical proximities and historical, cultural similarities. Fujian and Taiwan had gone through and currently are in different economic development stages. Taiwan is in the stage of post-industrialization and Fujian is in the intermediate stage of industrialization. By using the official statistics, changes of built-land in Fujian and Taiwan were analyzed in details. The results showed that these two provinces seemed to have the same characteristics of built-land changes, i.e., accelerating development, and concentrated distribution on both sides of the Taiwan Straits, forming a pattern with the economic layout of two sides acting in cooperation with eath other. If comparing different industrialized areas in Fujian with industrialized stages in Taiwan, it is clear that these two provinces seemed to have the same characteristics of synthesized index of built-land change （Lc）, i.e., which is from stabilization or comparative stabilization at the initial stages of industrialization to high expansion at the intermediate stages of industrialization, then followed by low consumption at later stages of industrialization, but the Lc of the initial and the later stages of industrialization in Taiwan were slightly higher than those in Fujian. The results from comparison on relevant indexes have shown： The industrial structure changing rate of Fujian is actually higher than that of built-land in Taiwan, but its using efficiency of regional built-land is also obviously lower than that in Taiwan in the intermediate and later stages of industrialization of Fujian. The major driving forces of the built-land changes in both provinces were analyzed in Causal Models of Path Analysis, and its result indicated that the difference in built-land changes of the two provinces is closely related to their economic development stages and industrial structure. Countermeasure for the realization of sustainable utilization of built-land in Fujian put forward in this article is to strengthen its intension and tap the latent power.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10964007)the Natural Science Foundation of Inner Mongolia,China (Grant No. 2009MS0110)
文摘The cyclotron mass of magnetopolarons in wurtzite InxGa1-xN/GaN quantum well is studied in the presence of an external magnetic field by using the Larsen perturbation method. The effects of the built-in electric field and different phonon modes including interface, confined and half-space phonon modes are considered in our calculation. The results for a zinc-blende quantum well are also given for comparison. It is found that the main contribution to the transition energy comes from half-space and interface phonon modes when the well width is very small while the confined modes play a more important role in a wider well due to the location of the electron wave function. As the well width increases, the cyclotron mass of magnetopolarons first increases to a maximum and then decreases either with or without the built-in electric field in the wurtzite structure and the built-in electric field slightly reduces the cyclotron mass. The variation of cyclotron mass in a zinc-blende structure is similar to that in a wurtzite structure. With the increase of external magnetic field, the cyclotron mass of polarons almost linearly increases. The cyclotron frequency of magnetopolarons is also discussed.
文摘The Tourism Bureau of Heilongjiang Province announces that a paleontological museum devoted to Quaternary fossil mammoths has been built in Qinggang County in that province. This museum, recently olticially opened, can be used to exhibit collections and conduct popular science education as well as scientific research （Fig. 1）.
基金supported by National Natural Science Foundation of China(No.51208425)Research Foundation of Northwestern Polytechnical University(No.JCY20130127)
文摘As-built building information model （BIM） is an urgent need of the architecture, engineering, construction and facilities management （AEC/FM） community. However, its creation procedure is still labor-intensive and far from maturity. Taking advantage of prevalence of digital cameras and the development of advanced computer vision technology, the paper proposes to reconstruct a building facade and recognize its surface materials from images taken from various points of view. These can serve as initial steps towards automatic generation of as-built BIM. Specifically, 3D point clouds are generated from multiple images using structure from motion method and then segmented into planar components, which are further recognized as different structural components through knowledge based reasoning. Windows are detected through a multilayered complementary strategy by combining detection results from every semantic layer. A novel machine learning based 3D material recognition strategy is presented. Binary classifiers are trained through support vector machines. Material type at a given 3D location is predicted by all its corresponding 2D feature points. Experimental results from three existing buildings validate the proposed system.
