h i g h l i g h t s• We propose a new method for modeling one-mode projection of bipartite networks. • Our modeling method breaks through the limitation of traditional methods. • Our one-mode collaboration network model outperforms available models. • We find that five mechanisms are common and crucial to collaboration networks. a b s t r a c tTraditional one-mode projection models are less informative than their original bipartite networks. Hence, using such models cannot control the projection's structure freely. We proposed a new method for modeling the one-mode projection of bipartite networks, which thoroughly breaks through the limitations of the available one-mode projecting methods by tagging the vertex information of bipartite networks in their one-mode projections. We designed a one-mode collaboration network model by using the method presented in this paper. The simulation results show that our model matches three real networks very well and outperforms the available collaboration network models significantly, which reflects the idea that our method is ideal for modeling one-mode projection models of bipartite graphs and that our one-mode collaboration network model captures the crucial mechanisms of the three real systems. Our study reveals that size growth, individual aging, random collaboration, preferential collaboration, transitivity collaboration and multi-round collaboration are the crucial mechanisms of collaboration networks, and the lack of some of the crucial mechanisms is the main reason that the other available models do not perform as well as ours.

Few studies have assessed the impact of regulatory actions on air quality improvement through a comprehensive monitoring effort. In this study, we designed saturation sampling of nitrogen oxides (NOX) for the counties of Los Angeles and Alameda (San Francisco Bay) before (2003-2007) and after (2008-2013) implementation of goods movement actions in California. We further separated the research regions into three location categories, including goods movement corridors (GMCs), nongoods movement corridors (NGMCs), and control areas (CTRLs). Linear mixed models were developed to identify whether reductions in NOX were greater in GMCs than in other areas, after controlling for potential confounding, including weather conditions (e.g., wind speed and temperature) and season of sampling. We also considered factors that might confound the relationship, including traffic and cargo volumes that may have changed due to economic downturn impacts. Compared to the pre-policy period, we found reductions of average pollutant concentrations for nitrogen dioxide (NO2) and NOX in GMCs of 6.4 and 21.7 ppb. The reductions were smaller in NGMCs (5.9 and 16.3 ppb, respectively) and in CTRLs (4.6 and 12.1 ppb, respectively). After controlling for potential confounding from weather conditions, season of sampling, and the economic downturn in 2008, the linear mixed models demonstrated that reductions in NO2 and NOX were significantly greater in GMCs compared to reductions observed in CTRLs; there were no statistically significant differences between NGMCs and CTRLs. These results indicate that policies regulating goods movement are achieving the desired outcome of improving air quality for the state, particularly in goods movement corridors where most disadvantaged communities live.

On the characteristics performance of national settlement value, there is not only a single settlement spatial organization characteristic, but also put up the relationship between the organizational structures of settlements. Through the study of field survey and literature on the settlement of ethnic groups upper reaches of Minjiang River, and questionnaire interview of villagers self-organization construction mode, to summarize the construction process between the special geographical environment and the villagers symbiotic relationship upper reaches of Minjiang River, analyze the choice between the Unique social, historical changes of ethnic settlement and Villagers diversified living styles, and point out the logic mechanism of the formation of spatial organization structure in ethnic settlement. At last, putting out that pointing at the spatial structure and characteristics of settlements in different regions should construct corresponding protection strategies and implementation paths in the spatial practice of institutionalized rural settlement.

Abstract-The primitive religion and the special ideological value of the Qiang minority have shaped the unique spatial characters of the settlement. How to use the cultural, social and ecological values of these traditional settlement spaces has become an important part of the urban and rural construction in ethnic areas. Based on the theory of sustainable development in harmony, this paper explores the protection and inheritance of traditional Qiang minority's settlement space in Sichuan province. Firstly, this paper is designed to establish dynamic relationship between social, economic and physical space of the settlement and construct a path of inheritance with sustainable development based on the subjective needs of traditional Qiang's settlements. Secondly, based on the pluralistic value of traditional Qiang's settlements, this paper puts forward the idea that only by inheritance of the social value and cultural belief of traditional Qiang's settlements can we protect the value property of traditional settlement space and the diversity of their environment and resources. Thirdly, based on the relationship between society, culture, ecology and settlement space, this paper explores transforming its historical and cultural value to economic capital for villagers' survival, strengthening the way of protection and inheritance by overall use of settlement space.