This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance th...This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts.展开更多
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century...A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.展开更多
Due to limited resources regarding port development,the contradiction between ports and cities has gradually become prominent.Taking China's coastal ports as an example,this paper measures the degree of coordinati...Due to limited resources regarding port development,the contradiction between ports and cities has gradually become prominent.Taking China's coastal ports as an example,this paper measures the degree of coordination between port development and urban environment,and analyzes its influencing factors.We find that this coordination degree is relatively low and needs to be further improved.The regression results of the ordinary panel model show that the scale of port logistics,port infrastructure construction,and the quality of economic development play a significant role in promoting the coordinated development of the port and the urban environment.The regression results of the threshold panel model show that the expansion of the port logistics scale is only conducive to promoting the coordinated development of the port and the urban environment when the levels of port infrastructure are relatively high.In addition,the promotion effect of the port logistics scale on the coordinated development of the port and the urban environment differs depending on the quality of economic development.Therefore,the relevant departments should pay more attention to the construction of port infrastructure and the quality of economic development,making appropriate adjustments to both in order to better promote the coordinated development of the port and city environment.展开更多
The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles a...The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles and procedures are presented in this paper. Indicators and methods for IEA may vary from case to case, but guidelines for selection of indicators and methods may be applicable for a specific case, so they are also introduced. Although great progress has been made in IEA, there is still a lot for future development. Prospects are presented as follows: (1) IEA at strategic level; (2) mechanisms for public involvement; (3) post project analysis; (4) cumulative impact assessment; and (5) application of new approaches such as expert system and GIS in IEA.展开更多
Environmental pollutants are causing worldwide damage to plants, forests and crop production, among which, gaseous and particulate metal pollutants from heavy industries in many developed countries are of major concer...Environmental pollutants are causing worldwide damage to plants, forests and crop production, among which, gaseous and particulate metal pollutants from heavy industries in many developed countries are of major concern. Many of these pollutants kill plants, cause stunted growth and premature aging, inhibit flowering and fruiting, cause a reduction in dry matter, and thereby results in a great reduction in crop production in many countries. This paper describes how an urban environment in Malaysia which is an agricultural based country affects plant growth and crop production.展开更多
Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization. But the applica...Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization. But the application of GIS in urban environmental management is still a new field and relevant researches are getting on tardily. As a subsystem of GIS, an urban environmental management geographic information system (UEMGIS) should be a complex multi-discipline and multi-objective tool to perform quantitative multi-dimension analysis and to transfer the results into an expression legible to an ordinary user. It should be a dynamic system of prompt functions based on upgradable databases, and be composed of many subsystems respectively specialized in items about water, air, waste and noise as well as relative standards and regulations. However, existing UEMGISs mostly rely on the basic GIS too much to design the actual requirements of applications and managements in themselves, and the unavailability of sufficient fundamental data has retarded their improvement. In the design of a UEMGIS, the standardization of data classification should be taken into consideration to make the data exchangeable and shareable among its subsystems and within every subsystem, and the applicable error limits for input data should be defined in accordance with the user抯 required precision of data out. Data acquisition can be easy and quick if remote sensing, global positioning system (GPS) and other technologies are combined with GIS. Rapidly progressing information technologies have been giving a bright prospect for the melioration of UEMGIS that will have great potential and wide application in environmental conservation.展开更多
When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization b...When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization by registering ground images to a 2D building boundary map which is generated from aerial images. Multilayer feature graphs (MFG) is employed to model building facades from the ground images. MFG was reported in the previous work to facilitate the robot scene understand- ing in urhan areas. By constructing MFG, the 2D/3D positions of features can be obtained, inclu- cling line segments, ideal lines, and all primary vertical planes. Finally, a voting-based feature weighted localization method is developed based on MFGs and the 2D building boundary map. The proposed method has been implemented and validated in physical experiments. In the proposed ex- periments, the algorithm has achieved an overall localization accuracy of 2.2m, which is better than commercial GPS working in open environments.展开更多
The article is dedicated to the aesthetic organization of the urban environment, interaction of architecture in line with the decorative sculpture and reflection of the above mentioned on the urban-scale. The given in...The article is dedicated to the aesthetic organization of the urban environment, interaction of architecture in line with the decorative sculpture and reflection of the above mentioned on the urban-scale. The given interaction is inclined to play significant role in terms of countering urgent issues and addressing contemporary concerns of society. The investigation is dealt with the study of decorative sculpture in the urban environment and its connections with the urban architecture展开更多
With the rapid development of the city,the concept of ecological environment has been integrated into everyone’s heart.In the new era,people also have higher requirements for the quality of living environment.However...With the rapid development of the city,the concept of ecological environment has been integrated into everyone’s heart.In the new era,people also have higher requirements for the quality of living environment.However,at this stage,with the development of urbanization and industrialization,the problem of environmental pollution has become more and more serious.Therefore,we must do a good job in urban environmental monitoring,pay attention to the protection of urban environment,design and implement effective governance methods,so as to improve the quality of environmental governance.This article analyzes the problems in urban environmental monitoring,and formulates reasonable treatment methods and suggestions.展开更多
The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urba...The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urban environmental climate maps and the application of climate atlas tool in Stuttgart,Germany were studied,and the multi-scale application of urban environmental climate maps in Stuttgart,Germany was summarized through the analysis of the pre-planning,current construction situation,and landscape reconstruction of the German"Stuttgart 21"plan case.Besides,other important measures to cope with climate change in German were proposed,and finally multi-scale practical strategies to cope with urban climate and environment were summarized to provide ideas and methods for improving China’s future urban climate environment.展开更多
Through the research and analysis of the BRICS countries in the academic community from 2012 to 2016,the development prospects of the BRICS summit and the BRICS countries were discussed,and the spirit of Xiamen welcom...Through the research and analysis of the BRICS countries in the academic community from 2012 to 2016,the development prospects of the BRICS summit and the BRICS countries were discussed,and the spirit of Xiamen welcoming to the BRICS summit was demonstrated. It can help Xiamen to better grasp and apply the historic opportunity of the BRICS summit,guide and promote the continuous development of social economy in Xiamen,consolidate and carry forward the fruitful results of reform and opening up in Xiamen,and turn Xiamen into a more " international fan" metropolis.展开更多
Earth observation (EO) provides the opportunity for periodic and spatially detailed assessment of the state of the environment in urban areas. In this study, the potential of EO based indicators (EI) to assess the sta...Earth observation (EO) provides the opportunity for periodic and spatially detailed assessment of the state of the environment in urban areas. In this study, the potential of EO based indicators (EI) to assess the state of environment in the urban agglomeration of Athens (UAA) is examined. EO based indicators as used in the study, include land surface temperature, land use, land cover and aerosols distribution. The indicators are also related to the household density and population density, as extracted from census data, for the same area. Indicators are applied at the municipal scale and are also used to estimate an aggregate environmental indicator (AEI), at municipal scale, by integrating all indicators mentioned above in a GIS environment. It is found that the urban agglomeration of Athens is practically “dichotomized”, by being divided in a western and eastern area, with considerably different environmental conditions. Results are considered important for focused interventions supporting environmental urban planning, whereas they represent the high potential of EO based indicators to monitor and assess the state of the urban environment.展开更多
Landscape is people’s evaluation of the environment which is better and more meaningful to visit.Therefore,a landscape must have a good environment.Landscape exists in nature as well as in cities.Every corner of a ci...Landscape is people’s evaluation of the environment which is better and more meaningful to visit.Therefore,a landscape must have a good environment.Landscape exists in nature as well as in cities.Every corner of a city can be a landscape.Its connection with the city and the citizens is inseparable.However,due to the acceleration of urbanization,there are still many problems in the urban environment.To solve these problems perfectly,we should work from the aesthetic value and planning orientation of the landscape.Therefore,this paper discusses and analyzes the problems of urban environment and how to use the aesthetic value and orientation to construct urban environmental landscape.展开更多
In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined t...In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.展开更多
An explosive increase of urban population, practically in all major cities and towns, has the consequent strain on the existing system manifested in an environmental chaos. The phenomena of accelerated urbanisation is...An explosive increase of urban population, practically in all major cities and towns, has the consequent strain on the existing system manifested in an environmental chaos. The phenomena of accelerated urbanisation is the main culprit, wherein besides bringing higher standard of living, it has also brought problems, as growth of dense and unplanned residential areas, environmental pollution, non-availability of services and amenities, solid waste etc. Remote sensing satellite data is suitable for urban land use mapping to get detail and up- to-date information for environmental management. Where as GIS helps in developing database system for urban information, which supports decision making process. Development of digital database on all aspects of land use and urban planning is the next crucial task for the future in which remote sensing based informa-tion is going to play a major role. In Delhi, rise in population and growth in economic activity has led to en-vironmental degradation. With this view an attempt has been made to study the quality of urban environment in the East district of Delhi, which is experiencing very high urban growth with 98.75% urban population in 2001. For this study Landsat ASTER (MSS) data of year 2001 (15 m Ground resolution), Guide map of the year 1982 and demographic and environmental data has been used. Eight parameters were selected, which affect the urban environmental quality, namely built-up area, open spaces, household density, occupancy ra-tio, population density, accessibility to roads, noise and smell affected area. The study shows that the quality of environment has been degraded when we compare 1982 and 2003 data. Most of the East district was in a better state of environment in 1982, but in 2003 things have been changed and now 50% area is in very good, fair and desirable condition. The public participation and involvement should be encouraged planning and decisions making for the improvement in better urban environmental quality.展开更多
This paper gives an overview of the presentations and discussions at the Sino British Workshop on Urban Environmental Enhancement and Sustainable Development held in Beijing from September 9—11, 1998. It summarises ...This paper gives an overview of the presentations and discussions at the Sino British Workshop on Urban Environmental Enhancement and Sustainable Development held in Beijing from September 9—11, 1998. It summarises the contributions from both the Chinese and British sides to the four major themes of urban sustainability: integrated environmental assessment, water pollution and management, urban transportation and its impacts on air quality, and environmental technology. It also identifies many areas of common interest for further collaboration.展开更多
Dramatic economic and social changes have taken place in Jiangyin city due to rapid and uneven urbanization and industrialization. The environmental degradation has followed driven by these changes since the 1980'...Dramatic economic and social changes have taken place in Jiangyin city due to rapid and uneven urbanization and industrialization. The environmental degradation has followed driven by these changes since the 1980's. With the pressures and effects of environmental deterioration, the city has implemented environmental management to hold back the trends of negative environmental changes. From the viewpoint of systems, DPSER is a good model for urban environmental changes to understand the causes, pressure, state, effect, existing responses and future action strategies. We took Jiangyin city, a developed city in South Jiangsu province, East China, as an example, and analyzed the characteristics of environmental changes and urban responses using DPSER model. Some operational strategies have been put forward to direct the city environmental management towards a sustainable road step by step.展开更多
Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System a...Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and GNSS.The complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior uncertainties.However,many efforts lack a balance between adaptability and robustness.In this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying noise.The field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.展开更多
基金supported by the National Defense Fundamental Research Projects (Nos. JCKY2020404C004 and JCKY2022404C005)Sichuan Science and Technology Program (No. 22NSFSC0044)。
文摘This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts.
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
基金supported by the Russian State Agrarian University–Moscow Timiryazev Agricultural Academy。
文摘A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.
基金supported by the National Social Science Foundation of China (Grant No. 20BGL290)the Key Scientific Research Project of Hunan Provincial Department of Education (Grant No. 19A210)the Postgraduate Scientific Research Innovation Project of Hunan Province (Grant No. CX20201115)
文摘Due to limited resources regarding port development,the contradiction between ports and cities has gradually become prominent.Taking China's coastal ports as an example,this paper measures the degree of coordination between port development and urban environment,and analyzes its influencing factors.We find that this coordination degree is relatively low and needs to be further improved.The regression results of the ordinary panel model show that the scale of port logistics,port infrastructure construction,and the quality of economic development play a significant role in promoting the coordinated development of the port and the urban environment.The regression results of the threshold panel model show that the expansion of the port logistics scale is only conducive to promoting the coordinated development of the port and the urban environment when the levels of port infrastructure are relatively high.In addition,the promotion effect of the port logistics scale on the coordinated development of the port and the urban environment differs depending on the quality of economic development.Therefore,the relevant departments should pay more attention to the construction of port infrastructure and the quality of economic development,making appropriate adjustments to both in order to better promote the coordinated development of the port and city environment.
文摘The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles and procedures are presented in this paper. Indicators and methods for IEA may vary from case to case, but guidelines for selection of indicators and methods may be applicable for a specific case, so they are also introduced. Although great progress has been made in IEA, there is still a lot for future development. Prospects are presented as follows: (1) IEA at strategic level; (2) mechanisms for public involvement; (3) post project analysis; (4) cumulative impact assessment; and (5) application of new approaches such as expert system and GIS in IEA.
文摘Environmental pollutants are causing worldwide damage to plants, forests and crop production, among which, gaseous and particulate metal pollutants from heavy industries in many developed countries are of major concern. Many of these pollutants kill plants, cause stunted growth and premature aging, inhibit flowering and fruiting, cause a reduction in dry matter, and thereby results in a great reduction in crop production in many countries. This paper describes how an urban environment in Malaysia which is an agricultural based country affects plant growth and crop production.
基金Funded by National Nature Science Foundation of China (Nos. 59978054 and 59838300)
文摘Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization. But the application of GIS in urban environmental management is still a new field and relevant researches are getting on tardily. As a subsystem of GIS, an urban environmental management geographic information system (UEMGIS) should be a complex multi-discipline and multi-objective tool to perform quantitative multi-dimension analysis and to transfer the results into an expression legible to an ordinary user. It should be a dynamic system of prompt functions based on upgradable databases, and be composed of many subsystems respectively specialized in items about water, air, waste and noise as well as relative standards and regulations. However, existing UEMGISs mostly rely on the basic GIS too much to design the actual requirements of applications and managements in themselves, and the unavailability of sufficient fundamental data has retarded their improvement. In the design of a UEMGIS, the standardization of data classification should be taken into consideration to make the data exchangeable and shareable among its subsystems and within every subsystem, and the applicable error limits for input data should be defined in accordance with the user抯 required precision of data out. Data acquisition can be easy and quick if remote sensing, global positioning system (GPS) and other technologies are combined with GIS. Rapidly progressing information technologies have been giving a bright prospect for the melioration of UEMGIS that will have great potential and wide application in environmental conservation.
基金Supported by the National High Technology Research and Development Program of China(No.2012AA041403)National Natural Science Foundation of China(No.60905061,61305107)+1 种基金the Fundamental Research Funds for the Central Universities(No.ZXH2012N003)the Scientific Research Funds for Civil Aviation University of China(No.2012QD23x)
文摘When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization by registering ground images to a 2D building boundary map which is generated from aerial images. Multilayer feature graphs (MFG) is employed to model building facades from the ground images. MFG was reported in the previous work to facilitate the robot scene understand- ing in urhan areas. By constructing MFG, the 2D/3D positions of features can be obtained, inclu- cling line segments, ideal lines, and all primary vertical planes. Finally, a voting-based feature weighted localization method is developed based on MFGs and the 2D building boundary map. The proposed method has been implemented and validated in physical experiments. In the proposed ex- periments, the algorithm has achieved an overall localization accuracy of 2.2m, which is better than commercial GPS working in open environments.
文摘The article is dedicated to the aesthetic organization of the urban environment, interaction of architecture in line with the decorative sculpture and reflection of the above mentioned on the urban-scale. The given interaction is inclined to play significant role in terms of countering urgent issues and addressing contemporary concerns of society. The investigation is dealt with the study of decorative sculpture in the urban environment and its connections with the urban architecture
文摘With the rapid development of the city,the concept of ecological environment has been integrated into everyone’s heart.In the new era,people also have higher requirements for the quality of living environment.However,at this stage,with the development of urbanization and industrialization,the problem of environmental pollution has become more and more serious.Therefore,we must do a good job in urban environmental monitoring,pay attention to the protection of urban environment,design and implement effective governance methods,so as to improve the quality of environmental governance.This article analyzes the problems in urban environmental monitoring,and formulates reasonable treatment methods and suggestions.
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)。
文摘The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urban environmental climate maps and the application of climate atlas tool in Stuttgart,Germany were studied,and the multi-scale application of urban environmental climate maps in Stuttgart,Germany was summarized through the analysis of the pre-planning,current construction situation,and landscape reconstruction of the German"Stuttgart 21"plan case.Besides,other important measures to cope with climate change in German were proposed,and finally multi-scale practical strategies to cope with urban climate and environment were summarized to provide ideas and methods for improving China’s future urban climate environment.
基金Supported by National Natural Science Foundation of China(71273209)
文摘Through the research and analysis of the BRICS countries in the academic community from 2012 to 2016,the development prospects of the BRICS summit and the BRICS countries were discussed,and the spirit of Xiamen welcoming to the BRICS summit was demonstrated. It can help Xiamen to better grasp and apply the historic opportunity of the BRICS summit,guide and promote the continuous development of social economy in Xiamen,consolidate and carry forward the fruitful results of reform and opening up in Xiamen,and turn Xiamen into a more " international fan" metropolis.
文摘Earth observation (EO) provides the opportunity for periodic and spatially detailed assessment of the state of the environment in urban areas. In this study, the potential of EO based indicators (EI) to assess the state of environment in the urban agglomeration of Athens (UAA) is examined. EO based indicators as used in the study, include land surface temperature, land use, land cover and aerosols distribution. The indicators are also related to the household density and population density, as extracted from census data, for the same area. Indicators are applied at the municipal scale and are also used to estimate an aggregate environmental indicator (AEI), at municipal scale, by integrating all indicators mentioned above in a GIS environment. It is found that the urban agglomeration of Athens is practically “dichotomized”, by being divided in a western and eastern area, with considerably different environmental conditions. Results are considered important for focused interventions supporting environmental urban planning, whereas they represent the high potential of EO based indicators to monitor and assess the state of the urban environment.
文摘Landscape is people’s evaluation of the environment which is better and more meaningful to visit.Therefore,a landscape must have a good environment.Landscape exists in nature as well as in cities.Every corner of a city can be a landscape.Its connection with the city and the citizens is inseparable.However,due to the acceleration of urbanization,there are still many problems in the urban environment.To solve these problems perfectly,we should work from the aesthetic value and planning orientation of the landscape.Therefore,this paper discusses and analyzes the problems of urban environment and how to use the aesthetic value and orientation to construct urban environmental landscape.
基金Under the auspices of Shanxi Scholarship Council of China(No.2017-003)
文摘In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.
文摘An explosive increase of urban population, practically in all major cities and towns, has the consequent strain on the existing system manifested in an environmental chaos. The phenomena of accelerated urbanisation is the main culprit, wherein besides bringing higher standard of living, it has also brought problems, as growth of dense and unplanned residential areas, environmental pollution, non-availability of services and amenities, solid waste etc. Remote sensing satellite data is suitable for urban land use mapping to get detail and up- to-date information for environmental management. Where as GIS helps in developing database system for urban information, which supports decision making process. Development of digital database on all aspects of land use and urban planning is the next crucial task for the future in which remote sensing based informa-tion is going to play a major role. In Delhi, rise in population and growth in economic activity has led to en-vironmental degradation. With this view an attempt has been made to study the quality of urban environment in the East district of Delhi, which is experiencing very high urban growth with 98.75% urban population in 2001. For this study Landsat ASTER (MSS) data of year 2001 (15 m Ground resolution), Guide map of the year 1982 and demographic and environmental data has been used. Eight parameters were selected, which affect the urban environmental quality, namely built-up area, open spaces, household density, occupancy ra-tio, population density, accessibility to roads, noise and smell affected area. The study shows that the quality of environment has been degraded when we compare 1982 and 2003 data. Most of the East district was in a better state of environment in 1982, but in 2003 things have been changed and now 50% area is in very good, fair and desirable condition. The public participation and involvement should be encouraged planning and decisions making for the improvement in better urban environmental quality.
文摘This paper gives an overview of the presentations and discussions at the Sino British Workshop on Urban Environmental Enhancement and Sustainable Development held in Beijing from September 9—11, 1998. It summarises the contributions from both the Chinese and British sides to the four major themes of urban sustainability: integrated environmental assessment, water pollution and management, urban transportation and its impacts on air quality, and environmental technology. It also identifies many areas of common interest for further collaboration.
文摘Dramatic economic and social changes have taken place in Jiangyin city due to rapid and uneven urbanization and industrialization. The environmental degradation has followed driven by these changes since the 1980's. With the pressures and effects of environmental deterioration, the city has implemented environmental management to hold back the trends of negative environmental changes. From the viewpoint of systems, DPSER is a good model for urban environmental changes to understand the causes, pressure, state, effect, existing responses and future action strategies. We took Jiangyin city, a developed city in South Jiangsu province, East China, as an example, and analyzed the characteristics of environmental changes and urban responses using DPSER model. Some operational strategies have been put forward to direct the city environmental management towards a sustainable road step by step.
基金funded by National Natural Science Foundation of China(No.61901015)。
文摘Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and GNSS.The complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior uncertainties.However,many efforts lack a balance between adaptability and robustness.In this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying noise.The field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.