Since the 18th century, the irritating but also fascinating scenes of urbanity--a complex phenomenon with cultural, social, political, economic, temporal, spatial, functional, and formal dimensions--have been describe...Since the 18th century, the irritating but also fascinating scenes of urbanity--a complex phenomenon with cultural, social, political, economic, temporal, spatial, functional, and formal dimensions--have been described in literary works. Many seemingly opposite facts, such as individuality/society, freedom/loneliness/socialization, anonymity/strangeness/identity/belonging, diversity/chaos/segregation, indifferent city-dweller/initiative citizenship, have been revealed through literary works, travel and utopian writing, urban theories, scientific studies, manifestos, and newspaper articles. On the one hand, there are those who advocate a life outside the city because they consider the problems produced by the city and the phenomenon of density which they perceive merely in quantitative terms, as unsolvable problems. On the other hand, there are those who see the production of loose urban fabric as a solution or those who accept the (seemingly) opposite facts of urbanity as positive values and therefore support city life. All of these ideas are still as actual today as they were in the past. We are often unable to use our citizen rights to the city, to encounter different classes (social/etlmic/religious), to experience heterogeneity as an aspect inherent in city life and in the route of our daily life--following the orders of the capitalist system mainly organized around work--and we are often drawn into the same districts on the same paths. Our perception of our urban environments may get monotonous and shallow, but the irritating yet fascinating features of the first big cities still exist and may be grasped and brought into consciousness. Throughout their architectural education, especially in urban design studios, students can be encouraged to investigate the rhythm of their daily life, the conditions of their urban environments, and discovering the city as an intellectual and sensual programme, so that the phenomenon of urbanity can be grasped not just on formal, but on various other dimensions as well. This study focuses on the process and outcomes of two urban studios located in Taksim Square and along the shores of the Golden Horn in Istanhul. Taking the multidimensional content of urbanity into account, acquired theoretically through literary works and studies on urban planning and its history, the main aim of these studios has been the phenomenological understanding of the dynamic content of urbanity by the students. Through creative analysis of permanent/temporary spaces engendered by the diversity of user profiles and actions discovered on phenomenological excursions, students examine the qualitative values of density and global and local dynamics. We believe that designing spaces as "prototypes" helps highlight the multidimensional content of urbanity. The present study aims not only to highlight the multidimensional content of urbanity, but also to encourage its discussion in architectural design education and to emphasize the positive contribution of theoretical readings and phenomenological studies to urban design studios. The present study also aims to emphasize the beneficial correlation of global and local dynamics as the two faces of urbanity; important more than ever for the big cities of the 21 st century if we advocate for a vivid and resilient city life and citizens.展开更多
This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou navigation.While navigating in urban canyons,the multipath effect is a kind of inte...This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou navigation.While navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou signal.Here,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback control.The proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle dynamics.It is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.展开更多
Local and urban squares play a crucial role in the presence and participation of people and in their interaction promotion.Alexander explained the profound geometric relations and discipline in nature,using the concep...Local and urban squares play a crucial role in the presence and participation of people and in their interaction promotion.Alexander explained the profound geometric relations and discipline in nature,using the concept of life phenomenon theory and living structures.He believes that humans can revive creatures through creating strong centers and an integrated whole.This study selects Avicenna tomb square and center of Aqajani Beig neighborhood,Hamedan.The main research questions include what the role of Alexander's theory of living centers is in promoting the social interaction in local and urban square and which pattern of Alexander’theory mostly affects social interactions in squares and how the individual factors impact social interactions in local and urban squares.Results reveals that patterns of Alexander^theory are efficient in promoting social interactions in local and urban squares.Individual factors are not effective in this regard,but strong centers and urban square contradictions are more effective in residents social interactions than that of void spaces and strong centers.Architects,planners,and urban designers can apply the results in designing new urban and local squares.展开更多
To set up self-rule organizations forsocial life of the mass at city’s local level isnot uncommon in other countries.But toset up a resident committee of completestructure and with overall functions thatserves as an ...To set up self-rule organizations forsocial life of the mass at city’s local level isnot uncommon in other countries.But toset up a resident committee of completestructure and with overall functions thatserves as an intermediate between the localpolitical organization and family units issomething peculiar to China.Then。展开更多
Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Be...Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Beijing city according to similarity theory. The conclusions were as follows.(1) Normalized standard deviations of wind speeds/ui * were plotted as a function only of a local stability parameter. The values under near-neutral conditions were 2.15, 1.61, and 1.19 at 47 m, 2.39, 1.75,and 1.21 at 140 m, and 2.51, 1.77, and 1.30 at 280 m, showing a clear increase with height. The normalized standard deviation of wind components fitted the 1/3 law under unstable stratification conditions and decreased with height under both stable and unstable conditions.(2) The normalized standard deviation of temperature fitted the.1/3 law in the free convection limit, but was quite scattered with different characteristics under near-neutral conditions. The normalized standard deviations of humidity and the CO2 concentration fitted the.1/3 law under unstable conditions, and remained constant under near-neutral and stable stratification. The normalized standard deviation of scalars, i.e., temperature, humidity, and CO2 concentration, all increased with height.(3) Compared with momentum, and the water vapor and CO2 concentrations, the turbulence correlation coefficient for heat was smaller under near-neutral conditions, but larger under both stable and unstable conditions. A dissimilarity between heat, and the water vapor and CO2 concentrations was observed in urban areas. The relative correlation coefficients between heat and each of momentum, humidity, and CO2 concentration(|rwT/ruw|, |rwT/rwc| and |rwT/ruq|) in the lower layers were always larger than in higher layers, except for the relative correlation coefficient between heat and humidity in an unstable stratification. Therefore, the ratio between heat and each of momentum, humidity, and CO2 concentration decreased with height.展开更多
文摘Since the 18th century, the irritating but also fascinating scenes of urbanity--a complex phenomenon with cultural, social, political, economic, temporal, spatial, functional, and formal dimensions--have been described in literary works. Many seemingly opposite facts, such as individuality/society, freedom/loneliness/socialization, anonymity/strangeness/identity/belonging, diversity/chaos/segregation, indifferent city-dweller/initiative citizenship, have been revealed through literary works, travel and utopian writing, urban theories, scientific studies, manifestos, and newspaper articles. On the one hand, there are those who advocate a life outside the city because they consider the problems produced by the city and the phenomenon of density which they perceive merely in quantitative terms, as unsolvable problems. On the other hand, there are those who see the production of loose urban fabric as a solution or those who accept the (seemingly) opposite facts of urbanity as positive values and therefore support city life. All of these ideas are still as actual today as they were in the past. We are often unable to use our citizen rights to the city, to encounter different classes (social/etlmic/religious), to experience heterogeneity as an aspect inherent in city life and in the route of our daily life--following the orders of the capitalist system mainly organized around work--and we are often drawn into the same districts on the same paths. Our perception of our urban environments may get monotonous and shallow, but the irritating yet fascinating features of the first big cities still exist and may be grasped and brought into consciousness. Throughout their architectural education, especially in urban design studios, students can be encouraged to investigate the rhythm of their daily life, the conditions of their urban environments, and discovering the city as an intellectual and sensual programme, so that the phenomenon of urbanity can be grasped not just on formal, but on various other dimensions as well. This study focuses on the process and outcomes of two urban studios located in Taksim Square and along the shores of the Golden Horn in Istanhul. Taking the multidimensional content of urbanity into account, acquired theoretically through literary works and studies on urban planning and its history, the main aim of these studios has been the phenomenological understanding of the dynamic content of urbanity by the students. Through creative analysis of permanent/temporary spaces engendered by the diversity of user profiles and actions discovered on phenomenological excursions, students examine the qualitative values of density and global and local dynamics. We believe that designing spaces as "prototypes" helps highlight the multidimensional content of urbanity. The present study aims not only to highlight the multidimensional content of urbanity, but also to encourage its discussion in architectural design education and to emphasize the positive contribution of theoretical readings and phenomenological studies to urban design studios. The present study also aims to emphasize the beneficial correlation of global and local dynamics as the two faces of urbanity; important more than ever for the big cities of the 21 st century if we advocate for a vivid and resilient city life and citizens.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.62320106008 and 62373114in part by the Collaborative Innovation Center for Transportation Science and Technology of Guangzhou under Grant No.202206010056.
文摘This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou navigation.While navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou signal.Here,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback control.The proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle dynamics.It is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.
文摘Local and urban squares play a crucial role in the presence and participation of people and in their interaction promotion.Alexander explained the profound geometric relations and discipline in nature,using the concept of life phenomenon theory and living structures.He believes that humans can revive creatures through creating strong centers and an integrated whole.This study selects Avicenna tomb square and center of Aqajani Beig neighborhood,Hamedan.The main research questions include what the role of Alexander's theory of living centers is in promoting the social interaction in local and urban square and which pattern of Alexander’theory mostly affects social interactions in squares and how the individual factors impact social interactions in local and urban squares.Results reveals that patterns of Alexander^theory are efficient in promoting social interactions in local and urban squares.Individual factors are not effective in this regard,but strong centers and urban square contradictions are more effective in residents social interactions than that of void spaces and strong centers.Architects,planners,and urban designers can apply the results in designing new urban and local squares.
文摘To set up self-rule organizations forsocial life of the mass at city’s local level isnot uncommon in other countries.But toset up a resident committee of completestructure and with overall functions thatserves as an intermediate between the localpolitical organization and family units issomething peculiar to China.Then。
基金supported by the National Nature Science Foundation of China (Grant Nos. 41275023, 91537212 & 410210040)
文摘Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Beijing city according to similarity theory. The conclusions were as follows.(1) Normalized standard deviations of wind speeds/ui * were plotted as a function only of a local stability parameter. The values under near-neutral conditions were 2.15, 1.61, and 1.19 at 47 m, 2.39, 1.75,and 1.21 at 140 m, and 2.51, 1.77, and 1.30 at 280 m, showing a clear increase with height. The normalized standard deviation of wind components fitted the 1/3 law under unstable stratification conditions and decreased with height under both stable and unstable conditions.(2) The normalized standard deviation of temperature fitted the.1/3 law in the free convection limit, but was quite scattered with different characteristics under near-neutral conditions. The normalized standard deviations of humidity and the CO2 concentration fitted the.1/3 law under unstable conditions, and remained constant under near-neutral and stable stratification. The normalized standard deviation of scalars, i.e., temperature, humidity, and CO2 concentration, all increased with height.(3) Compared with momentum, and the water vapor and CO2 concentrations, the turbulence correlation coefficient for heat was smaller under near-neutral conditions, but larger under both stable and unstable conditions. A dissimilarity between heat, and the water vapor and CO2 concentrations was observed in urban areas. The relative correlation coefficients between heat and each of momentum, humidity, and CO2 concentration(|rwT/ruw|, |rwT/rwc| and |rwT/ruq|) in the lower layers were always larger than in higher layers, except for the relative correlation coefficient between heat and humidity in an unstable stratification. Therefore, the ratio between heat and each of momentum, humidity, and CO2 concentration decreased with height.