Baigiamajame magistro darbe yra nagrinėjamos pagrindinės rekomendacinių sistemų socialiniuose tinkluose problemos: rekomendacijų tikslumas, pasyvūs vartotojai, neaiškios rekomendacijos. Iškeliami pagrindiniai tikslai, kuriais siekiama išanalizuoti rekomendacinių sistemų veikimo principus ir pasiūlyti metodą rekomendacinės sistemos efektyvumui ir rekomendacijų tikslumui gerinti. Analizuojama užsienio literatūra, atliekamas eksperimentas su realia duomenų baze. Analizuoti rezultatai vertinami skirtingų vartotojų grupių (pasyvūs, aktyvūs, tarpiniai vartotojai), analizuojamas kiekvienos grupės poveikis bendram rezultatui. Aprašytos aiškios rekomendacijos ir pateikti jų pavyzdžiai. Rezultatai vertinti trimis skirtingais kriterijais: PAP, PAVP ir ĮA. Pirmi du rodo skaičiavimo nuokrypius, trečiasis – įverčių apimtį. Atlikti penki bandymai skirtingomis sąlygomis ir pateikti kiekvieno bandymo bei bendri rezultatai. Išsikelti tikslai yra įgyvendinti, nes analizuojant gautus rezultatus, tiek bendras rekomendacijų tikslumas, tiek pasyvių vartotojų pagerėjo. Bendras pagerėjo 4% ir 11%, pasyvių vartotojų – 11% ir 17%. Darbe aprašomas modelis gali būti nesunkiai pritaikomas rekomendacinei sistemai. Šis baigiamasis darbas gali būti naudojamas kaip pagrindas ar literatūros šaltinis tolesniems tyrimams Lietuvoje. / The thesis analyses the main problems of recommender systems in social networks: the accuracy of recommendations, cold start users, uncertain recommendations. The main goals are raised, which are used to analyze the principles of processes in recommender systems, and to offer a novel method to improve the efficiency and the accuracy of recommendations. The foreign articles are discussed and the new method is implemented on an existing data set. The results are evaluated according to the different groups of users (cold start users, heavy raters and intermediate users) and the effect of each group to the main result is analyzed. The transparent recommendations are explained with the examples. The results are evaluated using three different metrics: MAE, MAUE and RC. The first two determine the deviation of the calculations the third determines the coverage of the ratings. Five experiments were made with different conditions and the results of each are presented along with the general results. The held purposes were accomplished because the accuracy of recommendations increased for all users and for cold start users as well. The benefit of the accuracy for all users is 4% and 11%, for cold start users 11% and 17%. The model described in the thesis can be easily incorporated to the recommender system. This thesis can be used as the basis of future work of recommender systems in Lithuania.

選擇到哪家餐廳用餐的問題，不論旅遊或家居都經常會遇到。大多數的人會先上網，尋找符合自己喜好且評價好的美食。然而網際網路發達，在人人都可上網分享的情況下，造成資訊氾濫超載。使得使用者上網瀏覽資料時，很容易找到不切合需求的資訊。解決此資訊超載的方法之一是餐廳推薦系統。儘管目前有很多的推薦應用程式或是分享平台，諸如TripAdvisor、iPeen愛評網、foursquare…等等，資料豐富但卻沒有針對個人偏好做推薦。 　　本研究有鑒於許多人在品嘗美食之前，會先拍照並在Facebook或Instagram打卡做紀錄、分享給朋友，打卡的次數可能意味著此餐廳的熱門度。且使用者選擇的美食類型偏好也可能受到聚餐目的的影響。因此開發出一款結合社群互動圈以及考量用餐情境的餐廳推薦系統。此系統先利用使用者所選擇的聚餐場合、價位、餐廳類型、熱門商圈等元素篩選出合適的餐廳，再利用Facebook打卡資料取得與使用者偏好相似的好友，依據好友的相似度推算出使用者對餐廳的喜好程度，推薦符合使用者興趣及需求的餐廳，協助使用者能夠更容易地找到自己所喜好的店家。 　　本研究的實作系統，經過評估測試，結果發現結合社群互動圈及考量用餐情境的個人化推薦能讓使用者更容易找到自己所喜好的餐廳，而在推薦內容中顯示好友對餐廳的評論，更有效的幫助使用者作決策。未來本推薦系統所使用之結合情境元素所設計的模式亦可應用至其他領域的推薦平台，如旅遊景點推薦或旅遊住宿推薦。 / Most people face the issue of deciding which restaurant to eat. Searching through the Internet is the first step that people usually do. However the rapid growth of information has overloaded the Internet users, it makes difficult to find the most appropriate information for decision-making. Certainly there are several restaurant recommender systems have been developed to solve the problem, such as TripAdvisor, iPeen, foursquare, etc; but few systems provide personalized and context-based recommendations. 　　The research intends to develop a restaurant recommender system that considers the factors of social network and context. Nowadays, when people eat, they like to take a picture and check in on Facebook or Instagram to share with friends, the numbers of check-in for a restaurant may mean the restaurant’s popularity. In addition, the gathering purpose and personal preferences may also affect the users’ decisions. Therefore the recommender system first used the variables of eating criteria such as place, price, types of food, eating environments to filter restaurants. The system then got the user’s similar friends from check-in data of Facebook. Through calculating friends’ similarity and their preference of restaurants, the recommender system finds the most fitted ones for the user to choose from. 　　The afterward system’s users testing data prove that this personalized and context-based recommendation system provides better information to help the user make their decisions. The same model can be replicated to other domain of recommender platforms.

The research is a study of the context of the life and work of John Hooper, Bishop of Gloucester and Worcester, 1551-1555. It charts the nature of his relationships with friends, patrons, mentors, colleagues, and lay and clerical supporters and opponents in England and on the Continent, through the study of ecclesiastical, political, business and economic, intellectual, official and judicial, kinship and social networks in which he was involved. Its purpose is to reveal the complex mix of societal and confessional pressures influencing Hooper's approach and constraining his freedom of manoeuvre, and to a large extent determining how successful he was at achieving change. The study reveals key determinants of the nature and direction of the Reformation in England. It shows that the pressure to change doctrinal allegiances and to accommodate reformed church practices challenged not only personal confessional loyalties but also the very framework of society; that is, familial and social ties, economic, business and judicial groupings, educational affiliations, and ruling oligarchies. Within these societal networks there existed the momentum for, and resistance to, religious change. Confessional allegiances were just part of a complex mix of political and social pressures that included the exercise of patronage and protection, the use of conflict and compromise, the practise of different obligations, allegiances and loyalties, the employment of status and kinship, and the accommodation of various alliances and means of association. All of these influenced Hooper's approach and scope for action. As such, the research provides insight into why and how, in the development of the newly-reformed church in England, thoroughgoing religious change was resisted and contained.

This thesis examines the space use, movement and contact rate patterns of a high- density, group-living, Eurasian badger (Meles meles) population in the UK naturally infected with bovine tuberculosis (bTB). Recently developed proximity logging devices were deployed on a representative sample of 51 badgers from eight different social groups to track their movements using radio-telemetry and to quantify their within- and between-group contact rates. Whilst interactions within social groups accounted for more than 90% of contacts, the entire study population was ultimately connected through interactions among individuals from neighbouring groups. Both within and between-group contacts, and also the use of denning sites, were heavily influenced by seasonal and demographic factors, which appear to be motivated to a large extent by reproductive behaviours. Nevertheless, by using social network analysis I found that badgers that tested positive for bTB were found to interact with fewer of their group members and for a shorter amount of time. Specifically these test-positive individuals were found to associate with test-negative group members significantly less than would be expected by chance. Those animals testing positive for bTB were also found to use outlying setts significantly more frequently than those that tested negative. The within and between-group contact rates of individuals were found to correlate with their sett use patterns. Those animals that spent less time interacting with group members and those that spent more time interacting with members of foreign social groups, were found to spend a greater proportion of their time at outlier setts. The findings in this thesis suggest a link between wider roaming behaviour and the disease status of an individual. This adds support to the argument that the social disruption of badger populations, for example through culling, may promote rather than alleviate the spread of bTB as a result of increased movement and contacts between groups. State-of-the-art technology has enabled me to demonstrate the strong influence that badger social organisation may have on the transmission of an economically significant infectious disease. My findings suggest that disease control measures might be enhanced by taking into account seasonal and individual-level variation in ranging behaviour and use of outlier setts, for example, by identifying and targeting functional groups of individuals, specific areas, or times of the year that contribute disproportionately to disease spread.

Cyber bullying is a form of bullying that did not receive enough recognition in our society until the year of 2004. That same year, the social network Facebook was launched and is now the most popular social network site for youths in Sweden and around the world. Cyber bullying is a new phenomenon where the normal form of bullying is taken into the world of technology by using various technical artefacts such as mobile phones, computers and tablets to access the Internet. In this study the youths will be sharing their views and experiences on this subject. Aim: The aim was to ascertain the experiences of cyber bullying according to Swedish youth between the ages of 11- 16 years old in a Swedish class in Stockholm. Method: This will be presented by empirical interviews with a qualitative approach, as a method to illustrate the youths perception of this phenomenon. Results: The study results show that Facebook serves as a tool keeping youths connected through computer-mediated communication. Youths can edit and optimize their presentations of themselves online and choose how much of their private information they want to share with others. Based on the study, it has also been shown that anonymity is not essential among bullies. According to the participants they know who has insulted them or their friends because they are using their real Facebook accounts, which differs from previous study. The reason behind this may be that youths have become more comfortable social networking and they find it easier when they cannot see the person's reaction when they receive the negative comment written, in comparison to if the comment would have been said in the classroom. The study has also shown that those who have been bullied online either go to the same school with the bully or have acquaintances. The more online-exposure for example; having many social network friends and publishing private information, an individual chooses to have with their Facebook account, the greater the risk of being cyber bullied. Conclusion: Even though this is a narrow study, it brings insights on youths experience and exposure to cyber bullying.

Research of social networks has revealed that certain components of network position can have an impact on organizational effectiveness, yet relatively little research has been conducted on network position and individual performance. This study sought to determine if a relationship exists between an employee's social network position and an individual's job performance. The participant organization was a network of individuals within an Information Technology (IT) department at a major defense company. A social network analysis (SNA) was conducted to determine the employee's network position, measured by centrality and constraint. Centrality refers to the extent to which an individual is connected to others. Constraint refers to how constrained or inhibited an individual is within the network. Performance was measured by annual appraisal ratings provided by the employee's supervisor. Hierarchical regression analysis was performed to determine relationships between the dependent variable (performance) and independent variables of centrality and constraint. Secondary variables also studied in relation to the model included education level, service years (tenure), job grade, and age. The overall model revealed 17% of variance explained. The primary predictors of network position, centrality and constraint, were not statistically significant predictors of performance ratings. Three variables, job grade, tenure and age, were found to be statistically significant predictors of employee performance. Further research is suggested to provide additional insight into the predictive value of these variables.

Vermont is widely-regarded as a hub for artisan cheese production, with more cheesemakers per capita than any other US state. Despite significant local and statewide support, out-of-state markets are essential to the long-term success of these small-scale producers. In spatially extended supply chains, retailers occupy a pivotal position. This thesis aims to examine the intermediary role of retailers in building social networks between producers and consumers. Consumers appreciate Vermont artisan cheese, in part, because it is embedded in a complex network of social values and relations related to where and how it is produced. Guided by social theories of consumption, sensory experience, and exchange, a transdisciplinary, mixed-methods study was conducted in order to better understand cheese retailers' role in this network. First, participant observation and ethnographic interviews at a specialty cheese shop demonstrated how highly specialized cheese retail professionals (known as a cheesemongers) communicate social information about Vermont artisan cheese to consumers in practice. Specialized narratives are transmitted to consumers through in-store signage and social interactions. These stories also involve the cheesemonger as traveler, developing specialized knowledge of Vermont artisan cheese by traveling to the place of production. A second site of participant observation at a national conference for artisan cheese professionals added breadth to the study. While cheesemongers appear to agree that a certain level of intrinsic quality is necessary for consumer acceptance and preference, many also see the importance of, and derive pleasure from, knowing and conveying the social story, and perceive this to be an important part of their professional role and identity. Second, social network analysis provided a broader examination of relationships between Vermont artisan cheesemakers and retailers in the region. In order to collect data on these relationships, an online survey was distributed to Vermont artisan cheesemakers and follow-up phone calls were conducted. A combination of statistical and network analyses was used to visualize the social structure of the network, identify key actors, and examine qualities of the relationships. The findings suggest that the social network for Vermont artisan cheese is a multiplex system, in which a cheesemaker's relative position in the network is the result of a complex balance--and sometimes compromise--between a cheesemaker's needs, goals, and desires and their various retailers' needs, goals, and desires. Moreover, geographic proximity, time, experience, convenience, cost, history, loyalty, and regard all appear to be important factors in the type of relationship cheesemakers have with retailers, and whether a relationship is established at all.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

A bridge connecting student's new multi-modal abilities and schooling can be built. Students choose between school and other activities outside of the classroom walls (and sometimes even inside the classroom) and schoolwork seems to be losing ground in the battle of spare time more and more. Students could benefit from an electronic space that incorporates their media know-how, their studies, and others in the classroom. Blogs, or weblogs, provide just that type of space by relying on the user's insightful writing and creativity to retain a dynamic position in the Internet blogging community. Blogs have the ability to better the writing classroom by providing an educational forum for dialogue, spatial creativity, and social awareness.

Objective: Numerous studies trying to find the causes and implications of binge drinking on college campuses have focused their attention on the heavy drinkers. The purpose of this study was to understand why and how college students choose to abstain from drinking. The study also examined the experiences of the abstaining college students on a campus where 83% of the student body drinks. Methods: Twelve undergraduate students from the University of Richmond participated in this qualitative study. Individual interviews using open-ended questions were conducted to ascertain the reasons for their abstinence and their experiences as college students. After the interviews, the 12 students were assigned to focus groups to discuss and compare their experiences and to test emergent themes.Results: The three most often mentioned reasons for the decision to abstain were (a) they wanted to maintain control over their body and environment, (b) it is illegal to drink under age 21 and (c) they did not want to disappoint their parents. The students described needing strong personal convictions about the decision to abstain in order to stand up to social pressures to fit in. Most of the students (11) made the decision during their high school years. A supportive network of peers and high parental expectations helped solidify the decision to abstain throughout high school. The transition period into college and the development of a social network is the most difficult time to be an abstainer, since most social activities revolve around drinking. The meaning they gave to their experience on campus was that it is more difficult to develop a social network as an abstainer, but the relationships are deeper and more genuine than those developed over nights of drinking. Conclusions: The choice to abstain from drinking is often made during high school and maintained through social support. The transition into college and the lack of a social network is a tenuous period during which the decision to abstain is challenged. University administrators need to look into alternative ways in which new students can develop their social network where drinking is not the primary focus.