For the majority of social species, group composition is dynamic, and individuals are interconnected in a heterogeneous social network. In this study I investigate the mechanisms underpinning social structure in the endangered southern resident killer whale (Orcinus Orca) population using a long term dataset, and explore the consequences of these. My results demonstrate that resource availability may be an important determinant of social network structure. A significant relationship between the connectivity of the social network and salmon abundance occurred, with a more interconnected network in years of high salmon abundance. As networks are non-random, highly connected individuals may play a key role in population processes such as information and disease transmission. While associations occurred both within and between matrilines, females had a significantly higher number of associates than males, as did older individuals of both sexes. Older males played a more important role in interconnecting the network. The attributes of group leadership were then investigated in matrilines and in individuals. Leadership was not a factor of size or mean age of matriline. However, there was a significant relationship between leadership score and the matriline sex ratio. Individually, females had higher leadership scores than males, and there was a positive correlation between leadership score and age in both sexes. I suggest that the oldest females have the highest 4 leadership scores due to increased ecological knowledge that comes with a prolonged lifespan. Using multi-generational records for two populations of killer whales, I show that both reproductive and post-reproductive mothers increase the survival of offspring, particularly in older male offspring. This is consistent with theoretical predictions, and may explain why female killer-whales have evolved the longest post-reproductive lifespan of all non-human animals. Given the role that individuals of high network centrality can play in population processes, understanding the driving forces behind social network structure is vital when designing effective conservation and management plans.

Frequent pattern mining is an important research areas in data mining. Since its introduction, it has drawn attention of many researchers. Consequently, many algorithms have been proposed. Popular algorithms include level-wise Apriori based algorithms, tree based algorithms, and hyperlinked array structure based algorithms. While these algorithms are popular and beneficial due to some nice properties, they also suffer from some drawbacks such as multiple database scans, recursive tree constructions, or multiple hyperlink adjustments. In the current era of big data, high volumes of a wide variety of valuable data of different veracities can be easily collected or generated at high velocity in various real-life applications. Among these 5V's of big data, I focus on handling high volumes of big data in my Ph.D. thesis. Specifically, I design and implement a new efficient frequent pattern mining algorithmic technique called B-mine, which overcomes some of the aforementioned drawbacks and achieves better performance when compared with existing algorithms. I also extend my B-mine algorithm into a family of algorithms that can perform big data mining efficiently. Moreover, I design four different frameworks that apply this family of algorithms to the real-life application of social network mining. Evaluation results show the efficiency and practicality of all these algorithms. / February 2017

Resilience refers to the capacity to quickly return to normal levels of functioning in the face of adversity. This capacity has previously been linked to social support. The purpose of this study was to investigate the role of social networks in the association between resilience and social anxiety in a clinical group with social anxiety disorder (n = 41) and a control group of university students (n = 40). The results showed that controls were significantly more resilient than the clinical group. Controls had significantly larger, more diverse and active social networks than the clinical group. Resilience was negatively associated with social anxiety in both groups. In the clinical group, there was a significant partial mediation effect of resilience on social anxiety through the size of the social network, a x b = –0.33, 95% CI [–0.718, –0.111]. Potential clinical applications of these results were discussed.

The social network sites (SNS) industry has recently shown an abnormal development pattern: An SNS could rapidly accumulate a large number of users, and then suffer a serious loss of users in a short time, which subsequently leads to the failure of the Web site in the highly competitive market. The user's social network site continuance is considered the most important factor for an SNS to keep its sustainable development. However, little knowledge of the user's SNS continuance raises the following research question: What factors could significantly influence the user's SNS continuance intention? To address this research question, I study the question from three lenses of research, including the I-view, the social interactivity view, and the trust based view. The I-view is an extension of the IS continuance model. From this research perspective, I tested the influence of the utilitarian factor (i.e., perceived usefulness) and the hedonic factor (i.e., perceived enjoyment) on the user's satisfaction in the I-view. In addition, I extend the umbrella construct, confirmation, into two sub-constructs, informativeness and self-actualization, and respectively study their influences on the utilitarian factor and the hedonic factor. I find that the user's perceived enjoyment has a significant positive effect on the user's satisfaction, thereby motivating the user to continue using the SNS. The perceived informativeness of an SNS and the user's self-actualization through information sharing with others on the Web site both have significant positive effects on the user's perceived usefulness and perceived enjoyment. From the social interactivity perspective, I suggest that a user's social gains could have a projection effect on the user's satisfaction in an SNS and his or her SNS continuance intention. Most previous studies emphasized on the influence of social connection outcomes (i.e., social capitals) on the user's behavioral intention, but ignored the fact that an individual would also evaluate social connections according to the quality of the information sharing process (i.e., frequency and volume of information being exchanged) during the social activities. This study indicates that an SNS user's perceived interactivity has a significant positive effect on the user's sense of belonging to a virtual community and perceived social gains. The social gains significantly positively influence the user's satisfaction in the Web site and intention to continue using the SNS. From the trust based view, I find that the user's trust in the social network sites and the user's trust in other members both have significantly positive effects on the user's SNS continuance intention. In addition, both of the trust based factors could also positively influence the user's perceived informativeness, self-actualization, and sense of belonging. The findings from the current study create a solid foundation for future SNS continuance research, and also provide several practical implications to SNS managers to increase the cohesion between users and the Web sites.

The present work starts with study of past and current methods from the field of analysis and visualization of social networks. Selected methods are then described in detail. Following part is devoted to research of current software. Selected applications are tested and evaluated according to their capability of showing a development in dynamic social networks -- networks with temporal data. Based on these researches an application is designed and implemented. This application can be used for analysis and visualization of a development of dynamic networks in time. Finally, the application is tested on co-authorship social network by means of the bibliographic database of scientific papers DBLP. The work also presents the results of the experiments with implemented algorithms.

Thesis advisor: Patrick McQuillan / The challenges facing our communities are complex, interconnected, and urgent (Kania & Kramer, 2011). Recognizing these challenges, policy makers, funders, and practitioners are turning to social partnerships as a promising strategy for community and educational change (Bess, 2015; Henig et al., 2015). Social partnerships involve the joining together of organizations from across sectors of society to tackle social problems (Crane & Seitanidi, 2014). The underlying premise of the Promise Neighborhoods program, one such social partnership, is that providing access to resources, services, and supports in a comprehensive manner will have the greatest effect on educational and community outcomes (U.S. Department of Education, 2018). This study seeks to shed light on the process of initiating and implementing a social partnership. In this study the author employed a two-phased, mixed methods design using social network analysis and interviews with organizational representatives to examine the network structures of communication and collaboration within one Promise Neighborhoods initiative: the Boston Promise Initiative. The sample for the social network analysis consisted of 33 individuals from 27 partner organizations. Further, follow-up interviews with 11 individuals were held to understand how network structures and processes might impact educational and community change. Findings from the social network analysis and qualitative interviews reveal networks of communication and collaboration rooted in a deep history of place-based change efforts, facilitating access to network resources and social capital among partner organizations. The findings highlight the importance of recognizing both challenges and opportunities of partnering with schools. Further, the findings highlight the importance of a lead organization’s ability to attend to both technical processes, such as facilitating communication among partners, and cultural processes, such as negotiating organizational identity. Taken together, the findings from this study point to the complex nature of cross-sector collaboration and identify structural factors and network processes that may impact the success of the efforts. By better understanding the structure and processes inherent in social partnerships, organizations can be better supported as they develop and implement cross-sector initiatives aimed at making meaningful change in their communities. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.

Thesis advisor: Sara Moorman / With the increasing digitalization of society, the line between private and public has blurred. Social network sites (SNSs) like Facebook and Instagram facilitate such a process, with users utilizing the sites for public displays of private emotions or events. What was once intimate conversation between two individuals or personal experience shared only with those in one’s physical company have become public conversations and shared experiences for networks of Friends and Followers to comment on, like, share, and survey. Consequently, social media has allowed for heightened expressions of grief, a formerly private experience, online through the use of images, words, and reactions. The current study uses survey and interview data to understand who uses social media to grieve the loss of a family member (a particularly private loss), why an individual might do this, and how such posting influences the grieving process for the social media user. / Thesis (BA) — Boston College, 2018. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Sociology.

Most research investigating impression formation during early stages of a relationship on social network sites adopts unrealistic, ecologically invalid social scenarios. This thesis used an ecologically valid social scenario to improve understanding of impression formation during the early stages of a relationship on social network sites. Three studies investigated how students get to know each other on social network sites in the weeks before starting university. A focus group study, a questionnaire study and an experiment demonstrated that incoming undergraduate students form impressions about groups of people (e.g. a group of housemates) and specific individuals (e.g. a housemate) during university transition. The studies highlighted that it is too simplistic to suggest that impression formation about a group of people is different from impression formation about a specific individual. Instead, the coherence of the social target, the nature of the affiliation with that social target, and the strategies used to get to know that social target on social network sites influence how confident students are in their impressions of each other during university transition. Explanations are proposed that, if substantiated, would require expansion of the Hamilton and Sherman’s and cues-filtered in theories of impression formation. The studies highlighted that impression formation and the influence of those three factors can partially explain the intensity of students’ worries about the academic and social aspects of their future university experience. The findings are practically applied as guidance for university and pastoral support services and further research is proposed to test the tentative explanations.

Interdisciplinary Research (IDR) has received a lot of attention from academics, policy-makers, and decision-makers alike. RCUK invests £3 billion in research grants each year (RCUK 2017); half of the grants are provided to investigators who hail from different departments. There is mounting awareness of the challenges facing IDR, and a large body of literature trying to establish how IDR can be analysed (Davidson 2015, Yegros-Yegros, Rafols et al. 2015). Of these, the majority have been qualitative studies and it has been noticed that there is a distinct lack of quantitative studies that can be used to identify how to enable IDR. The literature shows that many of the barriers to IDR can be classified as either cultural or administrative (Katz and Martin 1997, Cummings and Kiesler 2005, Rafols 2007, Wagner, Roessner et al. 2011), neither of which are easily changed over a short period of time. The perspective taken in this research is that change can be affected by enabling the individuals who conduct IDR. Herein lies the main challenge; how can these future leaders of IDR be identified so that they can be properly supported. No existing datasets were deemed suitable for the purpose, and a new dataset was created to analyse IDR. To isolate dynamics within an organisation, hard boundaries were drawn around research-organisations. The University of Bath journal co-authorship dataset 2000-2017 was determined to be suitable for this purpose. From this dataset a co-authorship network was created. To analyse this, established models from literature were adapted and used to identify differences in disciplinary and interdisciplinary archetypes. This was done through a correlational study. No statistically significant differences between such author archetypes were found. It was therefore concluded that an alternative approach was necessary. By adapting the networks framework to account for different types of links between edges, a multilayer perspective was adopted. This resulted in a rank-3 tensor, node-aligned framework being proposed, allowing disciplines to be represented in the network. By using this framework to construct the University of Bath multiplex co-authorship network, an exemplar structure was established through use of a series of proposed structural metrics. A growth model was proposed and successfully recreated the structure and thereby uncovered mechanics affecting real-world multiplex networks. This highlighted the importance of node entities and the layer closeness centrality. This implies that it is very difficult to carry over benefits across disciplines, and that some disciplines are better suited to share and adapt knowledge than others. The growth model also allowed an analytical expression for the rate of change of disciplinary degree, thereby providing a model for who is most likely to enable and sustain IDR.

Research into the social behaviour of wild animals living in groups has demonstrated the importance of social structure dynamics and their consequences for an individual’s fitness. Many aspects of animal behaviour and ecology, including interactions with conspecifics, habitat use and willingness to take risks, can be a reflection of personality. One of the key concerns of captive animal husbandry is the social environment, as it is regularly modified and can shape the social behaviour of the animals in question in different ways. In this thesis I explore how meerkat, Suricata suricatta, social dynamics and individual positions may differ between wild and captive groups; I explore personality in the context of social networks and, lastly, I explore how physical and husbandry factors vary across enclosures and how this corresponds to a variation in the social structure of meerkats. Differences were found between the fifteen groups of captive meerkats when considering association networks based on foraging and resting. Some of these differences could be explained by intrinsic differences between the groups. An individual’s position within a network as described by their centrality and closeness measures could be predicted by their age and status, but rarely by their sex. I did not detect consistent patterns of non-random assortment amongst group members based on their sex, age or status. Groups of wild and captive meerkats differed in various aspects of their social network structure. Such differences may be due to individuals occupying different network positions and the difference in their number and strength of their connections to other individuals. This distinct way of interacting and associating could be a result of group specific attributes, such as group size, and/or the attributes of the donor and recipient, including sex, status or age. Critically, the differences may be explained by the dissimilar living environment that each encounters. The current results suggest that a meerkat social network in captive conditions can be less consistent than in their wild environment in the way they associate with one another, and in the manner they occupy particular positions in the network. Principal component analysis of the four personality traits revealed two personality dimensions, Friendliness and Aggressiveness, across the fifteen groups of meerkats. However, within a subset of my data (five groups), Friendliness was the only measure that robustly captured consistent individual differences across at least one year. A relationship was not found between attributes and personality dimensions due to age, status, and sex. Individuals with high Friendliness scores were more central in networks of foraging competitions. Aggressiveness did not explain an individual’s position in any form of interaction. There was no evidence that meerkats preferentially associated with or avoid others based on each of their personality scores. A relationship was found in the way animals associate with one another in the resting network based on the size and complexity of the enclosure and the type of shelter. Individuals were less likely to associate with others of the same sex or dominance status in enclosures that were larger or more complex. All the six external measures (the size and complexity of the enclosure, the type of barrier and day shelter, environmental enrichment frequency and human contact) influenced how individuals interacted with other group members within grooming, playing and dominance networks. In general, it seems to be that the key features to address in meerkat management in zoos are those of enclosure size and complexity (and perhaps provision of adequate shelters). Providing captive meerkats with more naturalistic and complex enclosures can help to preserve their natural social system.