Users of social networking services such as Facebook often want to manage the sharing of information and content with different groups of people based on their differing relationships. The growing popularity of such services has meant that users are increasingly faced with the copresence of different groups associated with different aspects of their lives, within their network of contacts. However, few users are utilising the group-based privacy controls provided to them by the SNS provider. In this thesis we examine the reasons behind the lack of use of group-based privacy controls, finding that it can be largely attributed to the significant burden associated with group configuration. We aim to overcome this burden by developing automated mechanisms to assist users with many aspects of group-based privacy control, including initial group configuration, labeling, adjustment and selection of groups for sharing privacy sensitive content. We use a mixed methods approach in order to understand: how automated mechanisms should be designed in order to support users with their privacy control, how well these mechanisms can be expected to work, what the limitations are, and how such mechanisms affect users’ experiences with social networking services and content sharing. Our results reveal the criteria that SNS users employ in order to configure their groups for privacy control and illustrate that off-the-shelf algorithms and techniques which are analogous to these criteria can be used to support users. We show that structural network clustering algorithms provide benefits for initial group configuration and that clustering threshold adjustments and detection of hubs and outliers with the network are necessary for group adjustment. We demonstrate that public profile data can be extracted from the network in order to help users to comprehend their groups, and that contextual information relating to context, contacts, and content can be used to make recommendations about which groups might be useful for disclosure in a given situation. We also show that all of these mechanisms can be used to significantly reduce the burden of privacy control and that users react positively to such features.

Em um ambiente corporativo, depois de algum tempo, as pessoas sabem a quem recorrer quando necessitam de ajuda ou de algum conhecimento que não dispõem, caracterizando um contexto de múltiplas influências entre pessoas ou redes de relacionamentos. Desta forma, o trabalho proposto, teve como objetivo identificar os atores da rede de relacionamentos, que exercem maior influência no comportamento de segurança. Para isso, fomos buscar na literatura estudos de abordagens teóricas e práticas, que utilizassem conceitos sócio-antropológicos, de preferência trabalhos com enfoque na área nuclear, que possuíssem questionários de cultura de segurança, devidamente testados e avaliados por métodos estatísticos. Como resultado, identificamos inúmeros atributos que podem caracterizar uma cultura de segurança positiva e, extraímos quatro daqueles que mais apareciam nos diversos estudos. A partir daí, concebemos as questões que nos possibilitassem mapear e entender as redes sociais que influenciam sobre a formação e manutenção destas características. Então, aplicamos nossa pesquisa no âmbito do IPEN-CNEN-SP, no qual utilizamos a técnica de pesquisa tipo bola de neve para mapeamento das redes sociais de compartilhamento de idéias, bem como aplicamos também o questionário para mapear as crenças dos atores com significativo grau de influência (obtido a partir do levantamento de redes de influências). Embasado em técnicas de análise de redes sociais, obtivemos subsídios para comprovação de que as redes dos atores mais influentes são relevantes na formação de cultura de segurança do IPEN-CNEN-SP. / In a corporative environment, after a while, people know to whom to turn to when they require help or some knowledge non available at their disposal, characterizing a context of multiple influences among people or relationship network. This way, the proposed work had as objective to identify actors, from relationship network that exerts a higher influence in safety behavior. For this, we researched in the literature studies on theoretical and practical approaches, which would use social-anthropological concepts, especially works with approach in nuclear area, provided with questionnaires on safety culture, strictly tested and assessed via statistical methods. This resulted in the identification of a lot of attributes able to characterize a positive safety culture and from them extracting four of the most shown in various studies. From now on, there were conceived questions for making viable the mapping out and the understanding of social network responsible for influencing the building-up and the maintenance of these characteristics. So, it was applied in our research, within IPEN-CNEN-SP extent, the snowball type as research technique, for the mapping out of social network toward ideas sharing, as well it was applied the questionnaire intended for mapping out actors believes with a significant influence degree (obtained from influences network survey). Based in social network analyses techniques, we obtained subsides for proving that network from actors the most influent are relevant for the building-up of IPEN-CNEN-SP safety culture.

Em um ambiente corporativo, depois de algum tempo, as pessoas sabem a quem recorrer quando necessitam de ajuda ou de algum conhecimento que não dispõem, caracterizando um contexto de múltiplas influências entre pessoas ou redes de relacionamentos. Desta forma, o trabalho proposto, teve como objetivo identificar os atores da rede de relacionamentos, que exercem maior influência no comportamento de segurança. Para isso, fomos buscar na literatura estudos de abordagens teóricas e práticas, que utilizassem conceitos sócio-antropológicos, de preferência trabalhos com enfoque na área nuclear, que possuíssem questionários de cultura de segurança, devidamente testados e avaliados por métodos estatísticos. Como resultado, identificamos inúmeros atributos que podem caracterizar uma cultura de segurança positiva e, extraímos quatro daqueles que mais apareciam nos diversos estudos. A partir daí, concebemos as questões que nos possibilitassem mapear e entender as redes sociais que influenciam sobre a formação e manutenção destas características. Então, aplicamos nossa pesquisa no âmbito do IPEN-CNEN-SP, no qual utilizamos a técnica de pesquisa tipo bola de neve para mapeamento das redes sociais de compartilhamento de idéias, bem como aplicamos também o questionário para mapear as crenças dos atores com significativo grau de influência (obtido a partir do levantamento de redes de influências). Embasado em técnicas de análise de redes sociais, obtivemos subsídios para comprovação de que as redes dos atores mais influentes são relevantes na formação de cultura de segurança do IPEN-CNEN-SP. / In a corporative environment, after a while, people know to whom to turn to when they require help or some knowledge non available at their disposal, characterizing a context of multiple influences among people or relationship network. This way, the proposed work had as objective to identify actors, from relationship network that exerts a higher influence in safety behavior. For this, we researched in the literature studies on theoretical and practical approaches, which would use social-anthropological concepts, especially works with approach in nuclear area, provided with questionnaires on safety culture, strictly tested and assessed via statistical methods. This resulted in the identification of a lot of attributes able to characterize a positive safety culture and from them extracting four of the most shown in various studies. From now on, there were conceived questions for making viable the mapping out and the understanding of social network responsible for influencing the building-up and the maintenance of these characteristics. So, it was applied in our research, within IPEN-CNEN-SP extent, the snowball type as research technique, for the mapping out of social network toward ideas sharing, as well it was applied the questionnaire intended for mapping out actors believes with a significant influence degree (obtained from influences network survey). Based in social network analyses techniques, we obtained subsides for proving that network from actors the most influent are relevant for the building-up of IPEN-CNEN-SP safety culture.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Background: The purpose of this study was to determine the association between social media dependence and depressive symptoms and also, to characterize the level of dependence. It was a transversal, analytical research. Subjects and Methods: The stratified sample was 212 students from a private university that used Facebook, Instagram and/or Twitter. To measure depressive symptoms, Beck Depression Inventory was used, and to measure the dependence to social media, the Social Media Addiction Test was used, adapted from the Internet Addiction Test of Echeburúa. The collected data were subjected for analysis by descriptive statistics where STATA12 was used. Results: The results show that there is an association between social media dependence and depressive symptoms (PR [Prevalence Ratio] = 2.87, CI [Confidence Interval] 2.03–4.07). It was also shown that preferring the use of Twitter (PR = 1.84, CI 1.21–2.82) over Instagram (PR = 1.61, CI 1.13–2.28) is associated with depressive symptoms when compared to the use of Facebook. Conclusion: Excessive social media use is associated with depressive symptoms in university students, being more prominent in those who prefer the use of Twitter over Facebook and Instagram. / Revisión por pares

Team norms are one of the most frequently used explanations of how teams as a collective entity can influence individual member’s behaviors (Hackman & Walton, 1986; Bettenhausen & Murnighan, 1991; Feldman, 1984). Despite such importance, current theoretical and empirical development of team norms is relatively inadequate. In this dissertation, I view norm strength and norm enforcement as two central pillars of team norms, and specifically examine team norm enforcement from a social network perspective. I first develop a typology based on the existing literature and specify the behavior content of three types of norm enforcement mechanisms: sanction, recognition and learning. Second, I examine the impact of the structural and configural properties on team performance. This model was tested on 799 employees nested in 101 work teams from China. Results from the data analysis have offered partial support that the structural characteristics of norm enforcement network had impacts on team performance above and beyond norm strength.

Professional burnout refers to the development of negative emotions, cynical thoughts, and physical and mental exhaustion as a response to stressors associated with one’s career. Within the teaching profession, professional burnout has been associated with an increase in teacher attrition. In an effort to promote a positive school environment where teachers feel supported and committed to the profession, many administrators have implemented structured collaborative opportunities within their buildings. While personal relationships within the school network can provide a mitigating effect against professional burnout, the possibility exists that teacher leaders can be overcentralized and negatively impacted by the maintained relationships. By potentially forcing centralization on critical team members and emphasizing them as the “go-to” person for collaboration, schools may be inadvertently putting their best at risk for burnout. Using a mixed-methods design, the following study investigates the perceived benefits and constraints of centrality within the school network on reported burnout. The social networks at four elementary schools were analyzed to determine the level of connectivity for each certified staff member. Participants were asked to identify the colleagues with whom they collaborate. Using Social Network Analysis, the level of centrality (as measured by number of network connections both received and directed) was calculated for each participant based on number of network ties both received and directed. Centrality scores were included with previously identified variables associated with teacher burnout including level of perceived stress, perception of school environment, principal support, and other demographic data in a series of hypothesis tests to assess the relationship between network connectivity and reported burnout. A series of semi-structured interviews were conducted with a selection of participants to further explore the impact of network connections on participant burnout. The results of this exploratory study found that not all collegial relationships are beneficial. A significant positive relationship between number of collaborative ties directed toward a teacher and their depersonalization score on the Maslach Burnout Inventory was identified, indicating that individuals who are frequently identified as a collaborator report higher burnout. The findings from this study produce a unique perspective on collaboration within the school network. As has been reported previously, level of connectivity within the school network as measured by the number of teachers one can identify as collaborators appears to mitigate (or not significantly increase) a teacher’s risk of professional burnout. However, being identified as a collaborator by a large number of teachers (in-degree) significantly increases one’s risk for depersonalization behaviors.

Young children often have a profound interest that if nurtured, would develop to great social cues and skills thereby improving their social aspects of life. Parents can conveniently benefit from a swift data sharing in the collaborative scrutiny of their kid's participation, in public activities facilitated through the internet digital technology. To facilitate the involvement of shared activities among children, an interactive website is essential. The aim of my project is to develop a website that is intended to be an interactive platform for a variety of events selection. Additionally, the website will aid parents in the creation, discovery and reach for organized local events that fit their kid's interests in description and age. A variety of events will be availed at the website for scrutiny in finding friends, sharing and learning new activities. Similarly, it will be used for fun engagement. The website is implemented by using Microsoft Visual Studio 2012 Professional, C# programming language, and SQL Server Management Studio 2012 to handle the data.

Objective: The purpose of this pilot study was to examine the effect of an online social network used as an adjunct to a behavioral weight loss intervention on participants’ perceived social support and perceived self-efficacy using constructs of Social Cognitive Theory as a basis for website development. Methods: 13 adult women (mean age: 43 years of age, range: 25-63 years) participated in a 12-week behavioral weight-loss intervention with the option to access the Transformation Challenge Online Community (TCOC), an internet-based support and informational website. The TCOC was developed using constructs of the Social Cognitive Theory. Data analyzed included online site usage software and pre- and post-questionnaire results. Time spent online, unique visits to the webpage, and pre and post-intervention data were analyzed using a mixed methods approach. Results: Average time spent on TCOC was 95.6 minutes over the entire three month intervention (range: 0 – 287 minutes). Website usage varied widely ranging from a participant who never accessed the site to another participant who logged on daily and commented a total of 27 times. Perceived self-efficacy to maintain a learned health behavior without the aid of a professional, as well as overall perceived social support were statistically significantly greater post-intervention. Confidence in the TCOC’s ability to aid in making healthy lifestyle changes decreased significantly from pre- to post-intervention while website usage also decreased over time. Conclusions: The internet may be a valuable tool for improving perceptions of social support and increasing access to reliable information and education. A web-based intervention can be used as an adjunct to a face-to-face intervention to provide additional support and information, as well as used to reach groups who may not have access to a face-to-face option. Considerations should be given to the structure of the online program; the potential for dynamic, aesthetically pleasing self-regulation tools; and content that is tailored to the individual. Decreased usage of the website over time may reflect similar difficulties in maintaining participation in face-to-face weight loss interventions. Attention should also be given to the target audience as participant comfort levels and feelings towards using the internet may differ significantly between users and therefore impact outcomes.

Collaborative innovation is an important mechanism for firms to exchange and acquire external knowledge. Through collaboration, innovators convene and form networks that, in return, help overcome the boundaries of knowledge transfer. To have a better understanding of actors’ collaborating behaviours in innovation networks, we identify three pairs of roles: 1) do actors make connections or bonds with their partners? 2) do actors exchange their knowledge with internal or external partners? 3) do actors absorb or distribute knowledge? We examine the distribution and evolution of actors’ roles from these three perspectives by using social network analysis. In this thesis, we use thousands of patent data from the United States Patent and Trademark Office, to investigate the actors’ behaviours in the chemical industries of two Canadian regions, i.e. Montreal and Windsor-Sarnia. Based on the results of our analysis, Montreal, acting as a public-dominated region, shows a more complex distribution of roles, while Windsor-Sarnia with a private orientation indicates a simplex pattern. From the evolution perspective, the network of Montreal is more stable and diversified, with key actors being active in the local network for more extended periods. Unlike Montreal, Windsor-Sarnia faces a higher level of mobility and globalization.

Epidemiological models are used to inform health policy on issues such as target vaccination levels, comparing quarantine options and estimating the eventual size of an epidemic. Models that incorporate some elements of the social network structure are used for diseases where close contact is required for transmission. The motivation of this research is to extend epidemic models to include the relationship with a broader set of relevant real world network properties. The impact of degree distribution by itself is reasonably well understood, but studies with assortativity or clustering are limited and none examine their interaction. To evaluate the impact of these properties, I simulate epidemics on networks with a range of property values. However, a suitable algorithm to generate the networks is not available in the literature. There are thus two research aspects: generating networks with relevant properties, and estimating the impact of social network structure on epidemic behaviour. Firstly, I introduce a flexible network generation algorithm that can independently control degree distribution, clustering coefficient and degree assortativity. Results show that the algorithm is able to generate networks with properties that are close to those targeted. Secondly, I fit models that account for the relationship between network properties and epidemic behaviour. Using results from a large number of epidemic simulations over networks with a range of properties, regression models are fitted to estimate the separate and joint effect of the identified social network properties on the probability of an epidemic occurring and the basic reproduction ratio. The latter is a key epidemic parameter that represents the number of people infected by a typical initial infected person in a population. Results show that social network properties have a significant influence on epidemic behaviour within the property space investigated. Ignoring the differences between social networks can lead to substantial errors when estimating the basic reproduction ratio from an epidemic and then applying the estimate to a different social network. In turn, these errors could lead to failure in public health programs that rely on such estimates.