The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city...The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city's command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an 'instant history' of the global spatial economy before the global economic downturn undermines the global economy in late 2008. How- ever, the waxes and wanes of major cities' command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities arotmd the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the com- mand and control situation of different cities in the world.展开更多
Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big ...Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big city rapidly moves forward. But in the development at the same time, some of the issues are inevitable. The rapid development of the cities has attracted a large population, and there are more and more large factories, so that there is more and more pollution in the life and production, which brings greater security risks to the human life and health, and let the cities more difficult to manage. So how to solve these problems and make the cities develop better is a problem worth pondering.展开更多
Daqing is a mining city that was set up on wetland by exploiting and processing petroleum.This paper points out that net-group urban system is the optimization mode for Daqin g urban spatial structure through an alyzi...Daqing is a mining city that was set up on wetland by exploiting and processing petroleum.This paper points out that net-group urban system is the optimization mode for Daqin g urban spatial structure through an alyzing and appraising the present situation,c haracteristics,advantages and dis advantages of Daqing spatial structure.And the best way of optimizing Daqing urban spatial structure is to adopt sustainable development strategy,establish th e coordinated grade structure of urban system,con struct developed towns net system,p refect the function structure of the towns at all levels,make full use of resources an d strengthen environmental protection.Spatial structure of Daqing must be according-ly adjusted in order to adapt to the tr ansformation of future economy types and functions.Based on the foundation of keep-ing net group,the development shoul d be from disperse to moderate centra lization in order to give prominence to the multi-function of the central city.Constr ucting ruralizing city should be the future goal of Daqing City.展开更多
This paper discusses the relations between mass media and urban tribes, by Stafford Beer's viable system model (VSM). During 1950-2010, the influence of media and advertising over individual decision-making process...This paper discusses the relations between mass media and urban tribes, by Stafford Beer's viable system model (VSM). During 1950-2010, the influence of media and advertising over individual decision-making processes has deepened of age range to which have targeted advertising and expanded for Western world, leading the culture diversity, naturally given, toward only one standardized culture prevailing nowadays. In the 1960s they were the women, then the young people during 1970s, and then children in the 1980s and during the 1990s over early childhood, when we learnt to speak (3 years old), achieving brand loyalty among very young children and the brands of products for this age group. From this perspective, urban tribes have taken control of the lives of young people, offering a false freedom, at the moment of choosing "How to be yourself" from options given in the market as a "catalogue of predesigned identities". A phenomenon is so complex, so it requires a holistic framework able to make explicit its components and relations between them and the relationship with internal and external environment. In particular, the VSM provides a way to analyze communication's problems thus clarifying: how, when and where, repair and controlling into the organization, identifying strategies to improve decision-making. Given the recursive nature of the VSM, it is possible to navigate within the phenomenon, through different recursions' levels. It will help to define more assertive and effective policies by health authorities, education and government in general, and also help someone among young people to see themselves inside of a dynamic consumption and thus can leave the domain and enter into a recta-domain, with more wisdom and consciousness.展开更多
Support vector regression (SVR) method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study...Support vector regression (SVR) method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels. The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the most suitable parameters (insensitive loss function e, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ) are 0.001, 0.5, and 2 000, respectively.展开更多
This paper presents an optimization model for solving the planning problem of collection and transportation of solid waste in medium-sized cities. As final results, are expected to promote cost savings to the public c...This paper presents an optimization model for solving the planning problem of collection and transportation of solid waste in medium-sized cities. As final results, are expected to promote cost savings to the public coffers, as well as environmental benefits. The developed mathematical model is formulated as a problem of linear programming with mixed-integer variables and transcribed into software GAMS (general algebraic modeling system). The practical application was tested using data collected in the central region of a Brazilian city with approximately 90,000 inhabitants. The deterministic model used allowed an optimal solution. It was found after inclusion of restrictions that eliminated the appearance of sub-routes. It was concluded that the optimal routes allow for a 38% reduction in total distance traveled, which can generate savings of $320.00 per day regarding maintenance and fuel trucks.展开更多
Adopting the BOT (build-operate-transfer) delivery method has brought opportunities and challenges in construction time and quality for urban infrastructure. Many studies investigate the upstream issues of BOT proje...Adopting the BOT (build-operate-transfer) delivery method has brought opportunities and challenges in construction time and quality for urban infrastructure. Many studies investigate the upstream issues of BOT projects such as concessionaire selection criteria and risk factors. But the project execution becomes complicated such as the escalated quality supervision organization and procedure at the construction stage. This extra supervision may have constituted hidden redundancies as waste to economic sustainability. This paper investigated construction quality supervision of BOT projects to pinpoint adequate degree of supervision and detect redundant organization and procedures. The study adopted ten subway construction projects as cases in which five were from the traditional design-bid-build (DBB) and five from the BOT methods. Thirty six project participants including owners, contractors, designers, and concessionaire managers of the ten projects were interviewed to tell their views on these issues. The quality supervision measures of the DBB projects were used as the baseline and compared with those of the BOT projects. The research results show that the construction quality seems no difference for the DBB and BOT projects. Construction quality comes out of supervision but excessive supervision organization and procedures do not necessarily improve quality. This finding indicates that adequate degree of supervision is enough to achieve required quality to save immense paperwork for large construction projects.展开更多
The wind field and pollutant dispersion are predicted numerically in a local urban area with crowded buildings and heavy traffic.A domain decomposition method is used in the large eddy simulation,in which the urban ar...The wind field and pollutant dispersion are predicted numerically in a local urban area with crowded buildings and heavy traffic.A domain decomposition method is used in the large eddy simulation,in which the urban area is decomposed into a central area,where pollution is the major concern,and a surrounding region,where the pollutant distribution is not important.The composite model is proposed for the complex building-street layout.The fine grid mesh is used to resolve the buildings in the central area while the buildings are treated as roughness elements in the surrounding region where the coarse grids are used.The proposed numerical method is applied to simulate the wind field and pollutant dispersion from vehicle exhaust in the Rua Do Campo area of Macao.The results show that the composite model is an appropriate method for predicting wind field and pollutant dispersion in the crowded building area.展开更多
基金Foundation item:Under the auspices of Hui Oi Chow Trust Fund(No.200902172004)Mrs.Li Ka Shing Fund,Strategic Research Theme on Contemporary China,Small Project Funding provided by the University of Hong Kong(No.200807176152)
文摘The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city's command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an 'instant history' of the global spatial economy before the global economic downturn undermines the global economy in late 2008. How- ever, the waxes and wanes of major cities' command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities arotmd the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the com- mand and control situation of different cities in the world.
文摘Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big city rapidly moves forward. But in the development at the same time, some of the issues are inevitable. The rapid development of the cities has attracted a large population, and there are more and more large factories, so that there is more and more pollution in the life and production, which brings greater security risks to the human life and health, and let the cities more difficult to manage. So how to solve these problems and make the cities develop better is a problem worth pondering.
文摘Daqing is a mining city that was set up on wetland by exploiting and processing petroleum.This paper points out that net-group urban system is the optimization mode for Daqin g urban spatial structure through an alyzing and appraising the present situation,c haracteristics,advantages and dis advantages of Daqing spatial structure.And the best way of optimizing Daqing urban spatial structure is to adopt sustainable development strategy,establish th e coordinated grade structure of urban system,con struct developed towns net system,p refect the function structure of the towns at all levels,make full use of resources an d strengthen environmental protection.Spatial structure of Daqing must be according-ly adjusted in order to adapt to the tr ansformation of future economy types and functions.Based on the foundation of keep-ing net group,the development shoul d be from disperse to moderate centra lization in order to give prominence to the multi-function of the central city.Constr ucting ruralizing city should be the future goal of Daqing City.
文摘This paper discusses the relations between mass media and urban tribes, by Stafford Beer's viable system model (VSM). During 1950-2010, the influence of media and advertising over individual decision-making processes has deepened of age range to which have targeted advertising and expanded for Western world, leading the culture diversity, naturally given, toward only one standardized culture prevailing nowadays. In the 1960s they were the women, then the young people during 1970s, and then children in the 1980s and during the 1990s over early childhood, when we learnt to speak (3 years old), achieving brand loyalty among very young children and the brands of products for this age group. From this perspective, urban tribes have taken control of the lives of young people, offering a false freedom, at the moment of choosing "How to be yourself" from options given in the market as a "catalogue of predesigned identities". A phenomenon is so complex, so it requires a holistic framework able to make explicit its components and relations between them and the relationship with internal and external environment. In particular, the VSM provides a way to analyze communication's problems thus clarifying: how, when and where, repair and controlling into the organization, identifying strategies to improve decision-making. Given the recursive nature of the VSM, it is possible to navigate within the phenomenon, through different recursions' levels. It will help to define more assertive and effective policies by health authorities, education and government in general, and also help someone among young people to see themselves inside of a dynamic consumption and thus can leave the domain and enter into a recta-domain, with more wisdom and consciousness.
基金Projects(2007JT3018, 2008JT1013, 2009FJ4056) supported by the Key Project in Hunan Science and Technology Program, ChinaProject(20090161120014) supported by the New Teachers Sustentation Fund in Doctoral Program, Ministry of Education, China
文摘Support vector regression (SVR) method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels. The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the most suitable parameters (insensitive loss function e, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ) are 0.001, 0.5, and 2 000, respectively.
文摘This paper presents an optimization model for solving the planning problem of collection and transportation of solid waste in medium-sized cities. As final results, are expected to promote cost savings to the public coffers, as well as environmental benefits. The developed mathematical model is formulated as a problem of linear programming with mixed-integer variables and transcribed into software GAMS (general algebraic modeling system). The practical application was tested using data collected in the central region of a Brazilian city with approximately 90,000 inhabitants. The deterministic model used allowed an optimal solution. It was found after inclusion of restrictions that eliminated the appearance of sub-routes. It was concluded that the optimal routes allow for a 38% reduction in total distance traveled, which can generate savings of $320.00 per day regarding maintenance and fuel trucks.
文摘Adopting the BOT (build-operate-transfer) delivery method has brought opportunities and challenges in construction time and quality for urban infrastructure. Many studies investigate the upstream issues of BOT projects such as concessionaire selection criteria and risk factors. But the project execution becomes complicated such as the escalated quality supervision organization and procedure at the construction stage. This extra supervision may have constituted hidden redundancies as waste to economic sustainability. This paper investigated construction quality supervision of BOT projects to pinpoint adequate degree of supervision and detect redundant organization and procedures. The study adopted ten subway construction projects as cases in which five were from the traditional design-bid-build (DBB) and five from the BOT methods. Thirty six project participants including owners, contractors, designers, and concessionaire managers of the ten projects were interviewed to tell their views on these issues. The quality supervision measures of the DBB projects were used as the baseline and compared with those of the BOT projects. The research results show that the construction quality seems no difference for the DBB and BOT projects. Construction quality comes out of supervision but excessive supervision organization and procedures do not necessarily improve quality. This finding indicates that adequate degree of supervision is enough to achieve required quality to save immense paperwork for large construction projects.
基金the National Natural Science Foundation of China(Grant No. 10872109)the Foundation for Development of Science and Technology in Macao(Grant No. FDCT 055/2005/A)the Supercomputing Center of Chinese Academy of Sciences
文摘The wind field and pollutant dispersion are predicted numerically in a local urban area with crowded buildings and heavy traffic.A domain decomposition method is used in the large eddy simulation,in which the urban area is decomposed into a central area,where pollution is the major concern,and a surrounding region,where the pollutant distribution is not important.The composite model is proposed for the complex building-street layout.The fine grid mesh is used to resolve the buildings in the central area while the buildings are treated as roughness elements in the surrounding region where the coarse grids are used.The proposed numerical method is applied to simulate the wind field and pollutant dispersion from vehicle exhaust in the Rua Do Campo area of Macao.The results show that the composite model is an appropriate method for predicting wind field and pollutant dispersion in the crowded building area.