Social polarization and social cohesion during urban transformation have been focal research topics in urban geography. However, in the context of increased individual mobility and expanding activity space, this research approach, being too static and narrow in perspective, cannot fully comprehend the dynamic process of social cohesion or the micro-level mechanisms underlying the social cohesion impacts of urban physical or social environments. This paper first reviews the progress of the urban social cohesion research and discusses the limitations of the residential neighborhood-based approach. Based on the critical literature review, the paper proposes a space-time behavior framework to urban social cohesion research, which incorporates the perspectives of individual mobility and space-time constraints while investigating the complicated causal mechanisms between the urban built environments and social cohesion. The space-time behavior approach allows more accurate measurement of the dynamic geographical context of individual social interactions based on individual activity-travel behavior in everyday life, as well as more in-depth understanding of the processes in which geographical context factors affect social cohesions through intermediary mechanisms of space-time constraints, public contact potential, and space-time behavioral strategy.

As a new form of social differentiation, social differentiation in housing mix neighbourhoods is a new research topic faced by urban geographers. Exiting studies have found that residents of different housing types in housing mix neighbourhoods may still face social differentiation due to their different use of urban spaces and few social interactions. However, the research paradigm of conventional social differentiation research has 'The Neighbourhood Effect Averaging Problem' and cannot reveal the social differences within the same neighbourhood. The study of residents' spatial and temporal behavior provides theoretical and methodological support for revealing the social differentiation within a neighbourhood. Therefore, this paper first reviews the origin and development of the housing mix neighborhood policy and the argument on the relationship between housing mix and social integration. Then, it takes a literature review on existing research on housing mix neighborhoods. Based on the existing research progress, a research framework for the social differentiation of the housing mix neighborhood from the residents' behavioral perspective is constructed. On the one hand, the behavior spaces represent the spaces for residents to experience and communicate in daily life. On the other hand, the behavior spaces represent the utilization of different urban spaces by different groups, thus forming "social differentiation in the trajectory of daily life".

Social integration of immigrants has become an important goal purposed by worldwide cities in the context of increasing social mobility. Inter-group social cohesion between migrants and local residents has been a new theme of Chinese urban studies. Urban planning and geography have long emphasized the impact of public space on social cohesion, focusing on the inclusiveness attitude fostered by encounters in public space. However, international literature has debated on the mechanism of public space and migrants' social integration in the context of individual mobility. Drawing on the theoretical and methodological basis from time geography and the activity-based approach, this study constructs a holistic research framework to understand the relationships among mobility-based public space exposures, activity-mobility patterns, and social integration outcomes of migrants. Based on three dimensions of space, time and behavior, this framework constructs the continuous individual activity-trip chain in multiple spatial contexts, hoping to reveal the inter-group social interaction and social cohesion effect of public space in different time scales. This study also contributes to the inclusive urbanization strategy in China.

Against the backdrop of globalization and rapid urbanization, increasing differences between various social groups in cities, particularly racial and ethnic groups, have been witnessed due to their diverse socio-cultural backgrounds and daily-life habits. The present study summarizes the existing Western and Chinese literature on racial/ethnic residential segregation. It concludes that, echoing the "mobilities turn" of urban studies, more and more writings on socio-spatial segregation have adopted the new mobilities paradigm by addressing the limitations of conventional residential-based perspective. Specifically, while past studies mostly conceptualized socio-spatial segregation in terms of residential locations (the extent to which members of different social groups live apart) through the use of census data, such conventional residential-based perspective of segregation ignores people's experience of segregation in the daily activity locations other than residential neighborhoods, thus evoking increasing scholarly attention to the analyses of segregation in individual activity spaces. Four research foci can be identified from this new strand of studies, namely intergroup difference in activity-travel behavior, measurement of racial/ethnic segregation from an activity-space perspective, mobility disadvantage of ethnic minorities, and hybrid geographical analyses of the subjective experience of activity-space segregation. Through summarizing the contributions and limitations of the existing studies, the present study proposes a new, integrated research framework on ethnic socio-spatial segregation through the perspective of space-time behavior, especially the time-geographic discourse on space-time constraints as an effective theoretical lens to decipher the roles of ethnic collective routines in shaping the minorities' experience of segregation. Such a framework is conducive to better comprehending of socio-spatial segregation in the transitioning Chinese cities, as well as more insights into the everyday life and sociospatial integration of different ethnic groups (especially the ethnic minorities).

How residents share their activity space around neighborhood is conducive to creating face-to-face social contact among neighbors, thus enhancing social understanding, neighborhood trust and neighborhood integration. Based on behavioral geography theory, this paper proposes a path framework of considering the interaction among physical space, shared activity space and social psychological space. Then this paper constructs a potential public contact analysis method on residents' neighborhood shared activity space studies. Four key aspects in potential public contact analysis are discussed, including structure, level, scale and locations. The extensity and intensity index measurement are proposed to measure potential public contact at both neighborhood level and individual level. This method uses the single-mode and dual-mode networks in the social network analysis to characterize the connections among residents through shared activity locations. Based on the survey data in suburban Shanghai, the paper finds that the extensity of potential public contact is relatively high while the intensity is relatively low. There are significant differences in potential public contact level among different neighborhoods and individuals. This study can provide support for the construction of suburban neighborhood living circles and neighborhood governance.

Studies of urban socio-spatial segregation has been increasingly benefited from the availability of space-time behavioral big data. The latter can well enrich the existing insights of activity-space segregation, which were predominantly based on conventional datasets such as activity diary data with substantially smaller sample sizes. Specifically, while studies with conventional datasets only adopted residential population as a proxy of the socioeconomic structures in the activity places, the use of space-time behavioral big data can effectively unravel the temporal variation of the socioeconomic structures by tracing the changing locations of the population over different time periods. Echoing the emerging strand of studies that utilized space-time behavioral big data to examine socio-spatial segregation, this paper presents a review of the existing studies through summarizing the types of data and analytical approaches used in those studies as well as the relevant contributions. Most of the existing studies were found being derived from three types of spacetime behavioral big datasets, namely cellphone data, social media data and transportation-derived data. Among the existing studies, three major contributions can be identified. First, the existing studies had unraveled the temporal variations and periodic patterns of socio-spatial segregation that were manifested at multiple temporal scales. Second, facilitated by space-time behavioral big data, the existing studies managed to measure individual socio-contextual exposure (i.e., co-presence) in a real-time manner. Third, the existing studies extended the analytical lens of socio-spatial segregation by including data of social network and tweet-based subjective attitudes. The present paper thus draws attention to the underrated potentials of spacetime behavioral big data of conducting critical-quantitative analyses.