SEMIPARAMETRIC REGRESSION AND GRAPHICAL MODELS

Semiparametric regression models that use spline basis functions with penalization have graphical model representations. This link is more powerful than previously established mixed model representations of semiparametric regression, as a larger class of models can be accommodated. Complications such as missingness and measurement error are more naturally handled within the graphical model architecture. Directed acyclic graphs, also known as Bayesian networks, play a prominent role. Graphical model-based Bayesian 'inference engines', such as bugs and vibes , facilitate fitting and inference. Underlying these are Markov chain Monte Carlo schemes and recent developments in variational approximation theory and methodology.     

Family Formation and Close Social Ties Within Religious Congregations

The study of family and religion has yet to elaborate on the social ties that connect these two important and changing institutions. Specifically, how does family formation (i.e., marriage and childrearing) impact social ties to religious communities? Using longitudinal data from the Portraits of American Life Study (2006–2012) and fixed effects regression models that control for time‐stable heterogeneity (N = 1,314), this study tests the effects of marriage and childrearing on changes in close congregational social ties. Fixed effects estimates suggest that marriage actually decreases close social ties to religious congregations, whereas rearing children within marital unions increases them. Thus, it is children, not marriage per se, that actually integrates married couples into religious communities. These contrasting effects tend to be the strongest among young adults, but they weaken with age as well as marital duration.     

Strength matters: Tie strength as a causal driver of networks’ information benefits

Studies of social networks have often taken the existence of a social tie as a proxy for the transmission of information. However, other studies of social networks in the labor market propose that the likelihood of information transmission might depend on strength of the tie; and that tie strength is a potentially important source of the tie's value. After all, even if job seekers have social ties to those who have valuable job information, the seekers will gain little information benefit when the ties do not actually transmit the information. This paper clarifies the conditions under which social ties might provide information benefits. We use a survey vignette experiment and ask MBA students about their likelihood of relaying job information via strong ties (to friends) or weak ties (to acquaintances), holding constant the structural locations spanned by the tie and job seekers' fit with the job. The results support the claim that strength of tie has a causal effect on the chances of information transmission: potential referrers are more likely to relay job information to their friends than to acquaintances. The larger implication of these findings is that whatever benefits there might be to using weak ties to reach distant non-redundant information during job search, these benefits need to be considered against the likely fact that people connected via weak ties are less likely to actually share information about job opportunities than are people to whom the job seeker is strongly tied.     

Who gets evicted? Assessing individual,neighborhood, and network factors

The prevalence and consequences of eviction have transformed the lived experience of urban poverty in America, yet little is known about why some families avoid eviction while others do not. Applying discrete hazard models to a unique dataset of renters, this study empirically evaluates individual, neighborhood, and social network characteristics that explain disparities in displacement from housing. Family size, job loss, neighborhood crime and eviction rates, and network disadvantage are identified as significant and robust predictors of eviction, net of missed rental payments and other relevant factors. This study advances urban sociology and inequality research and informs policy interventions designed to prevent eviction and stem its consequences.     

The association between social support networks and maternal employment: a comparison of western German,eastern German,and migrant mothers of preschool-aged children

A lack of adequate childcare can delay mothers’ return to the labor market after childbirth. This paper examines whether social support with childcare by kin and friends facilitates maternal employment in the first 72 months after childbirth. Using data from the German Socio-Economic Panel (SOEP) 1993–2009, a comparison of natives (n?=?1409) and migrants (n?=?411) in corporative-conservative western Germany with mothers in former socialist eastern Germany (n?=?528) shows that kinship support is positively associated with maternal employment when public childcare is limited. Western German and migrant mothers return to work sooner if they are surrounded by kin. But kin do not provide support for maternal employment in eastern Germany, where public childcare is more easily accessible and continuous female employment is a prevalent social norm. Friendship networks, by contrast, are most valuable for maternal employment if they complement public childcare.     

What is gained and what is left to be done when content analysis is added to network analysis in the study of a social movement: Twitter use during Gezi Park

As social movements relying on the weak ties found in social networks have spread around the world, researchers have taken several approaches to understanding how networks function in such instances as the Arab Spring. While social scientists have primarily relied on survey or content analysis methodology, network scientists have used social network analysis. This research combines content analysis with the automated techniques of network analysis to determine the roles played by those using Twitter to communicate during the Turkish Gezi Park uprising. Based on a network analysis of nearly 2.4 million tweets and a content analysis of a subset of 5126 of those tweets, we found that information sharing was by far the most common use of the tweets and retweets, while tweets that indicated leadership of the movement constituted a small percentage of the overall number of tweets. Using automated techniques, we experimented with coded variables from content analysis to compute the most discriminative tokens and to predict values for each variable using only textual information. We achieved 0.61 precision on identifying types of shared information. Our results on detecting the position of user in the protest and purpose of the tweets achieved 0.42 and 0.33 precision, respectively, illustrating the necessity of user cooperation and the shortcomings of automated techniques. Based on annotated values of user tweets, we computed similarities between users considering their information production and consumption. User similarities are used to compute clusters of individuals with similar behaviors, and we interpreted average activities for those groups.     

Reconsidering “community liberated”: How class and the national context shape personal support networks

The “community liberated” thesis has been influential in describing contemporary social support systems. Specifically, “community liberated” argues that people do not seek support in their immediate neighborhood but rather entertain a network of far-flung ties to support-providing alters. This paper uses personal network data from six countries – Australia, Germany, the US, Austria, Hungary and Italy – to evaluate this argument and shows that the degree of liberation of one's community is strongly linked to one's socioeconomic status – specifically, one's education level. Additionally, we describe strong country-level heterogeneity in the spatial dynamics of personal support networks and find national contexts to be moderating the effect of education on community liberation, especially in Italy and Hungary, thus suggesting network geographic dispersion to be linked to national economic structures and labor markets. The paper thus elucidates the effect of two different, yet related social contexts on personal networks: the class context and the national context.     

Disaster response on September 11, 2001 through the lens of statistical network analysis

The rescue and relief operations triggered by the September 11, 2001 attacks on the World Trade Center in New York City demanded collaboration among hundreds of organisations. To shed light on the response to the September 11, 2001 attacks and help to plan and prepare the response to future disasters, we study the inter-organisational network that emerged in response to the attacks. Studying the inter-organisational network can help to shed light on (1) whether some organisations dominated the inter-organisational network and facilitated communication and coordination of the disaster response; (2) whether the dominating organisations were supposed to coordinate disaster response or emerged as coordinators in the wake of the disaster; and (3) the degree of network redundancy and sensitivity of the inter-organisational network to disturbances following the initial disaster. We introduce a Bayesian framework which can answer the substantive questions of interest while being as simple and parsimonious as possible. The framework allows organisations to have varying propensities to collaborate, while taking covariates into account, and allows to assess whether the inter-organisational network had network redundancy—in the form of transitivity—by using a test which may be regarded as a Bayesian score test. We discuss implications in terms of disaster management.     

中国经典诗词主题现实化的整合理论诠释

概念整合理论起源于心理空间理论,是关于复合语言单位意义整合生成的一种认知学说,目前已成为认知诗学的一个重要组成部分,被广泛用于文学文本的分析和研究之中。在中国经典诗词中,涉及主题思想现实化的整合模式有镜像型网络整合模式、单域型网络整合模式和双域型网络整合模式。镜像型网络整合模式的特点是四个心理空间的组织框架是相同的,其中两个输入空间的所有元素彼此之间都呈现出映射关系,诗词的主题思想在两个输入空间的对比整合中产生。在单域型网络整合中,两个输入空间的组织框架是不同的,而且只有其中一个输入空间的组织框架被投射到合成空间为该空间提供组织框架,继而被作为解读诗词主题思想的基础。同单域型网络整合一样,双域型网络整合的两个输入空间在组织框架上也非常不同,但两个输入空间的组织框架均有一部分结构或特征被投射到合成空间,通过组合等认知运作机制而产生诗词的主题思想。     

通信企业“三网融合”方案设计研究

随着经济和技术的发展,传统的业务服务已经不能满足人们的需求,“三网融合”已经成为网络业务发展的必然趋势。通过对“三网融合”国内外现状的研究,分析了当今“三网融合”面临的问题,结合通信企业的实际情况,提出采用分布式流媒体技术进行通信企业“三网融合”方案设计,并针对不同规模通信企业,提出了紧凑型组网、城域网本地组网、多级分布式组网三种组网方案。该“三网融合”设计方案可以有效地节省骨干网带宽、保证QoS,提高用户满意度,对各级通信企业搭建多媒体数据中心具有一定推广作用。