published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

Part of the natural progression of any romantic relationship is that, over time, individuals will meet and form connections with each other’s friends and family (Milardo, 1982). Interestingly, the examination of social network introductions has largely been neglected by researchers. We do not know when couple members introduce each other to their friends and parents. We also do not know what effect, if any, these network introductions have on future relationship outcomes. The present study addressed these gaps. Specifically, I examined when couple members typically met each other’s friends and parents for the first time, whether relationship quality influenced the likelihood of making these introductions, and whether these introductions predicted later relationship outcomes (i.e., relationship quality, likelihood of breakup, and post-breakup adjustment). In the present study, participants in new romantic relationships (less than 6 months duration) completed a survey every two weeks for nine months. In each survey, participants indicated whether friend and family introductions had occurred, their current relationship quality, and whether they had broken up with their partners since the previous survey. If individuals reported having broken up, they were asked about their reactions to the breakup. Results revealed that friends were typically introduced before parents, and that relationship quality predicted the likelihood of newly dating individuals introducing their parents (but not friends) to their romantic partners. Largely, network introductions failed to predict later perceptions of relationship quality but did influence the likelihood of relationship dissolution over the course of the study. Furthermore, introductions to participants’ mothers predicted worse emotional reactions to a breakup, and introductions to participants’ fathers and best friends were associated with greater relationship longing. The results of this study represent an important first step in understanding when individuals introduce their romantic partners to their friends and family and how these introductions influence relationship development. / text

The present study examines the influence of social bonds on recidivism for a random sample of 250 male offenders released from Texas prisons since 2001. Social bonds are defined as the offender being employed, being married, or seeking educational pursuits. Based on life-course theory, developed by Sampson and Laub (1990), the researcher hypothesized that offenders released from prison who developed attachments (social bonds) would have less likelihood of recidivating than offenders who did not develop attachments (social bonds). Additionally, the researcher hypothesized that recidivists who developed attachments (social bonds) would have longer periods crimefree before re-incarceration than recidivists who lacked attachments (social bonds). The researcher used hierarchical binary logistic regression and Cox proportional hazard modeling to test the hypotheses. Although social bonds did not decrease the likelihood of re-incarceration, Cox proportional hazard modeling found that recidivists who obtained employment upon release from prison had longer periods before recidivating than those who did not obtain employment. The results indicate that employment may temporarily motivate offenders released from prison to avoid re-incarceration, but the affects appear to diminish over time. Social workers providing services to offenders released from prison should be aware that the influence of employment on desistance from crime might weaken over time, so they should continuously measure their clients' motivation levels regarding the desire to avoid re-incarceration.

Low quality information such as spam and rumors is a nuisance to people and hinders them from consuming information that is pertinent to them or that they are looking for. As social networks like Facebook, Twitter and Google+ have become important communication platforms in people's daily lives, malicious users make them as major targets to pollute with low quality information, which we also call as Denial of Information (DoI) attacks. How to analyze and detect low quality information in social networks for preventing DoI attacks is the major research problem I will address in this dissertation. Although individual social networks are capable of filtering a significant amount of low quality information they receive, they usually require large amounts of resources (e.g, personnel) and incur a delay before detecting new types of low quality information. Also the evolution of various low quality information posts lots of challenges to defensive techniques. My work contains three major parts: 1). analytics and detection framework of low quality information, 2). evolutionary study of low quality information, and 3). detection approaches of low quality information. In part I, I proposed social spam analytics and detection framework SPADE across multiple social networks showing the efficiency and flexibility of cross-domain classification and associative classification. In part II, I performed a large-scale evolutionary study on web page spam and email spam over a long period of time. In part III, I designed three detection approaches used in detecting low quality information in social networks: click traffic analysis of short URL spam, behavior analysis of URL spam and information diffusion analysis of rumors in social networks. Our study shows promising results in analyzing and detecting low quality information in social networks.

Thesis (MTech. degree in Marketing)--Tshwane University of Technology, 2011. / Focuses primarily on the decision-making of students in the acquisition and usage of wireless internet products and services in the Tshwane Metropolitan area.

Sociologists have long studied mate choice patterns to understand the shape of stratification systems. Romantic pairing involves intimacy and trust, and is therefore a prime indicator of the extent to which members of different social groupings (race/ethnicity, social class, education, religion) accept each other as social equals. The majority of this literature focuses on marriage, given the commitment marriage implies and the availability of nationally-representative data. In this dissertation, I examine the opposite end of the relationship spectrum: The initial screening and sorting process whereby strangers consider each other as potential mates; express interest in some subset of this population but not others; and find that this interest is or is not reciprocated. This beginning stage in mate choice is particularly important for our understanding of social boundaries because personality factors are likely to matter less and social characteristics to matter more. Yet because these initial forays into relationships are typically unobserved, we know very little about whom people consider as potential mates in the first place. I ask the following questions, corresponding to three empirical chapters: First, how do individuals from different status backgrounds vary in the types of strategies that they pursue and the degree of success that they achieve? Second, what underlying dynamics of homophily, competition, and gender asymmetry give rise to observed patterns of interaction, and under what circumstances do some of these boundaries break down? Third, how do strategies as well as preferences vary at different stages of selection, and at what point is homogeneity created? To answer these questions, I use detailed longitudinal data from a popular online dating site. These data are particularly useful for the study of social inequality not only due to the unique quantity and nature of information that is available, but also because online dating has become one of the primary ways that singles meet and marry today. / Sociology

Relationship marketing is an important part of the development of brands. The following report conceives the role of relationship marketing and how brands can use social networks as a key for unlocking a relationship with their consumer. This report presents the managerial implications on relationship marketing, the importance of dialogue, and social media. This report is for marketers to understand the importance of initiating, developing and maintaining a relationship with consumers and translate the concepts so that brands can successfully apply them into social networks. / text

This dissertation consists of three essays in Economic Theory. The rst essay proposes and studies a new solution concept for games with incomplete information. In game theory, there is a basic methodological dichotomy between Harsanyi's \game-theoretic" view and Aumann's \Bayesian decision-theoretic" view of the world. We follow the game theoretic view, propose and study interim partially correlated rationalizability for games with incomplete information. We argue that the distinction between this solution concept and the interim correlated rationalizability studied by Dekel, Fudenberg and Morris (2007) is fundamental, in that the latter implicitly follows Aumann's Bayesian view. Our main result shows that two types provide the same prediction in interim partially correlated rationalizability if and only if they have the same in nite hierarchy of beliefs over conditional beliefs. We also establish an equivalence result between this solution concept and the Bayesian solution{a notion of correlated equilibrium proposed by Forges (1993). The second essay studies the relationship between correlated equilibrium the redundancy embedded in type spaces. The Bayesian solution is a notion of correlated equilibrium proposed by Forges (1993), and hierarchies of beliefs over conditional beliefs are introduced by Ely and Peski (2006) in their study of interim rationalizability. We study the connection between the two concepts. We say that two type spaces are equivalent if they represent the same set of hierarchies of beliefs over conditional beliefs. We show that the correlation embedded in equivalent type spaces can be characterized by partially correlating devices, which send correlated signals to players in a belief invariant way. Since such correlating devices also implement the Bayesian solution, we establish that the Bayesian solution is invariant across equivalent type spaces. The third essay studies the existence of equilibria for rst-price sealed bid auctions when bidders form a network and each bidder observes perfectly their neighbors' private valuations. Asymmetry in bidders' positions in the network creates asymmetry in bidders' knowledge. We show the existence of pure-strategy equilibrium. / text

Low-income students of color have the difficult task of navigating their educational pathways in an era of resegregation, where they have higher chances of being tracked to lower academic courses (Mickleson & Heath, 1999) and are more likely to attend low-performing, racially and socioeconomically isolated high schools (Orfield & Lee, 2005). Research promotes the positive educational outcomes of integrated school settings (Wells, 1995), but limited research contextualizes (Wells, 2001) the experiences of low-income students of color in these settings. In light of research on the impact of the racial and socioeconomic composition of a high school on students’ educational outcomes, this dissertation used social capital and network theory to examine how networks of opportunity in accessing postsecondary resources differed between one integrated and one high poverty, high minority high school. Interviews of students and faculty identified by students as institutional agents (Stanton-Salazar, 1997)—individuals who connect students to postsecondary resources—helped frame the two high school portraits (see Lawrence-Lightfoot & Davis, 1997). Without systematic supports in both the integrated and segregated high school settings, only a select group of students were tied to resources that would lead them to their postsecondary aspirations. Students connected to postsecondary resources were at a structural advantage due to opportunities, such as enrollment in advanced placement (AP) courses, which would help broaden their networks of opportunity. In contrast, most students without the same structural advantages as high achieving students often felt lost navigating high school, disconnected from academics, and misdirected in navigating their postsecondary trajectories. Consequently, although the integrated high school was perceived as the gateway to accessing better educational opportunities, stratification occurred, tracking low-income and students of color to non-college preparatory courses. Therefore, low-income and students of color who transferred to the integrated high school in search of better educational opportunities received limited academic preparation similar to what was offered to them in their former low-performing, high poverty, high minority high school. The findings suggest that without both institutional and structural transformations and systematic supports, school integration alone is not the single element to offering greater educational opportunities to low-income and students of color. / text