Peer-to-peer applications enable a group of users to create a communications framework from scratch without the need of a central service provider. This is achievable via the aggregation of resources each one of them provide, creating a completely distributed collaborative environment based in a flat hierarchy of users, without the need for centralization. Usually, peer-to-peer applications are conceptualized as a global network, without any kind of logical segmentation or segregation as far as resource availability is concerned. At every model, any peer may access any resource available within the network just by being able to reach the peer that provides such resource. Although having a unique huge open network may be desirable for some applications, there are cases in which it might be interesting to create different, but not necessarily disjoint, groups of peers operating under the same global peer-topeer network. In order for peer groups to be able to operate effectively in a global peer-to-peer network, additional security services must be provided. These mechanisms should allow peers to be able to prove group membership to other members of the group, so they can be granted access to group resources, as well as ensuring that resource discovery and message exchange between peer group members remain secure. A group may need to limit membership for various reasons, such as ensuring privacy, anonymity or enforcing that peer group members are up to some specific parameter (data shared, performance, computing power, etc.) The goals of this PhD. thesis are twofold, the reason being the fact that securing a peer group can be divided at two distinct, but interrelated, layers: • Enabling effective group membership, starting from the process by which any peer becomes part of a peer group and then, following, the mechanisms by which such peer may prove its membership to other group members for the rest of the membership's lifecycle (peer group access control). • Providing a secure environment for standard operations within a peer group, which functions once any peer's membership to the group has already been established. Typical operations at this layer are those of resource location and retrieval, or messaging. In order to achieve the former goal, basic group membership and access control scenarios are categorized and formalized as part of the research work in order to assess which are the current challenges. From this study, we present a generic model proposal that fulfils the objectives of autonomy, keeps a pure peer-to-peer model and the possibility to be used in different peer-to-peer frameworks. The later goal focuses in secure mechanisms in order to provide basic security services to both resource discovery and message exchange. However, in contrast with group membership models, where a generic approach is feasible, peer group operation security is intimately tied to each specific peer-to-peer framework, since each one specifies resource location and messaging primitives in a different manner. For that reason, a specific one has been chosen for the research work: JXTA. Such election is due to the fact that JXTA's architecture is entirely based on the concept of peer groups, since it was the one to first define the concept of peer group, providing an excellent testbed for peer group research

Niemals zuvor in der Geschichte der Technik hat eine Technologie eine so rasante Verbreitung erfahren hat, wie es mit Smartphones und Tablet PCs (digitale Medien) erlebt wurde (Moura und Carvalho 2010). Diese erweisen sich als digitale Alleskönner bzw. Minicomputer mit einem polyfunktionalen Leistungs- und Anwendungsumfang. Es verwundert nicht, dass „die Lebenswelt mit digitaler Technik […] alltägliches Handeln in nahezu allen Kontexten [präformiert].“ (Kerres 2017, S. 22) und mit einem hohen Nutzungszuspruch korrespondiert. In Deutschland beläuft sich die Anzahl der Smartphone-Nutzer auf 57 Millionen und dies bei jährlichen Zuwachsraten (Bitkom e.V. 2018).Jedoch trügt diese vermeintlich breite, gesellschaftliche Akzeptanz und die Nutzung digitaler Medien scheint sich als altersspezifisches Phänomen zu präsentieren. Liegt die Abdeckung mit Smartphones in der Altersgruppe der 14- bis 49jährigen bei über 95 Prozent (Bitkom e.V. 2018), nutzen lediglich 41 Prozent der Personen ab 65 Jahren ein Smartphone1 (Lutter et al. 2017). Dabei nimmt das Nutzungsverhalten mit zunehmenden Alter ab (Barczik 2019). Dies ist umso erstaunlicher, da digitale Medien speziell für ältere Erwachsene Möglichkeiten zur Alltagserleichterung bieten (Mori und Harada 2010, Leung et al. 2012, Thimm 2013). Überdies ermöglichen Smartphones und Tablet-PCs ortsunabhängige Interaktionsmöglichkeiten (Feist und McDougall 2013) und befördern damit die soziale Teilhabe. Feist und McDougall 2013 sprechen modernen Informations- und Kommunikationstechnologien (IKT) sogar die Möglichkeit zu, den Alter(n)sprozess gelingend zu unterstützen. Dies lässt sich mit Beispielen wie Mobile Healthcare oder Ambient Assistent Living Systeme untersetzen. Entgegen dieser Vorteile wirft sich unweigerlich die Frage auf, wodurch die gegebene altersbedingte Digital Divide verursacht wird? [... aus der Einleitung]

Submitted by Maike Costa (maiksebas@gmail.com) on 2016-03-02T11:38:53Z No. of bitstreams: 1 arquivototal.pdf: 2660356 bytes, checksum: 2624ede45ecf10ac3aea241d8f40b9c4 (MD5) / Approved for entry into archive by Clebson Anjos (clebson.leandro54@gmail.com) on 2016-03-09T22:20:24Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 2660356 bytes, checksum: 2624ede45ecf10ac3aea241d8f40b9c4 (MD5) / Approved for entry into archive by Clebson Anjos (clebson.leandro54@gmail.com) on 2016-03-09T22:22:24Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 2660356 bytes, checksum: 2624ede45ecf10ac3aea241d8f40b9c4 (MD5) / Made available in DSpace on 2016-03-09T22:22:40Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2660356 bytes, checksum: 2624ede45ecf10ac3aea241d8f40b9c4 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Children are increasingly more inserted in consumer relations, and in this context, the Tweens (children from 7 to 12 years) emerge as a promising public, for they are avid consumers, but vulnerable for being in a preliminary phase that may overvalue the benefits consumption. By listening to the voice of the children themselves, this study aimed to analyze how social relationships influence Tweens’ consumption of goods and brands. In order to achieve the general objective, we identified (1) how the context of consumption and interpersonal relationships influence the consumption of goods by Tweens, (2) how do relationships with peers are affected by the symbolic and functional aspects related to appropriation of goods and brands (3) how they deal with “not having”, in front of groups and in their individuality, and (4) how parents guide their consumption. For this we adopted a methodology of qualitative, exploratory characteristics, through in-depth interviews with the children and their family (mother or grandmother). The interviews with the children were initially developed through the e-collage technique, which served as guiding for the conduction the interviews. The collected data was analyzed by the use of content analysis technique. The results indicate that the Tweens are influenced by the market environment, parents and peers in different levels according to the categories of products. It was found that material goods facilitate interaction in groups while the charge for to have the "right" property can generate constraints affecting the status, self-esteem and self-concept. It also identified that the mothers caring for their children to have socially appropriate goods, with the concern that they do not have problems in their social relationships. / As crianças estão cada vez mais inseridas em relações de consumo, nesse contexto, os Tweens (crianças de 7 a 12 anos) despontam como um público cobiçado pelo mercado, pois são consumidores ávidos. Nesse contexto essas crianças podem ser vulneráveis ao consumo por estarem em uma fase liminar (fase de transição) entre infância e adolescência e por tanto podem supervalorizar o status proporcionado pelo consumo. Ao ouvir a própria voz das crianças, este estudo teve por objetivo analisar como as relações sociais influenciam o consumo de bens e marcas desses Tweens. Para atingir o objetivo geral identificou-se (1) como o contexto do consumo e as relações interpessoais influenciam o consumo de bens dos Tweens, (2) como as relações com os pares são afetadas pelos aspectos simbólicos e funcionais relacionados à apropriação de bens e marcas, (3) como eles lidam com o “não ter” perante os grupos e em sua individualidade e (4) como os pais orientam o seu consumo. Para tal adotou-se uma metodologia de caráter qualitativa e exploratória por meio de entrevistas em profundidade com as crianças e com suas responsáveis (mães ou avó). As entrevistas com as crianças foram desenvolvidas em duas etapas, inicialmente foi utilizada a técnica projetiva de e-colagem, na qual foram produzidos painéis de imagens digitais, que serviu como guia para conduzir as entrevistas que foram conduzidas por um roteiro semi-estruturado. Os dados coletados foram analisados pela técnica de análise de conteúdo. Os resultados indicaram que os Tweens são influenciados pelo contexto do mercado, pais e pares de acordo com as categorias dos produtos em diferentes níveis. Identificou-se que os bens materiais podem facilitar a interação das crianças nos grupos ao mesmo tempo em que a cobrança em ter os bens “corretos” pode gerar constrangimentos entre eles afetando sua autoestima, o autoconceito e como o status de cada um nos grupos. Identificou-se também que as mães se esforçam para que seus filhos tenham bens socialmente adequados, com a preocupação de que eles não venham a sofrer discriminação ou qualquer tipo de problemas em suas relações sociais com os pares.

Philosophiae Doctor - PhD / In general, peers have a tendency to influence others positively and negatively. In the main, transition from school to higher education causes some students to experience stress; to respond negatively to new conditions; and to engage in risk behaviour, which hinders epistemological access, negatively affects performance, and often delays graduation. Nonetheless, participation in peer group activities has advantages and potentialities, which are often neglected in popular scholarly discourse. The main research question of the study was to investigate the experiences of peer pressure among first-year students? This study adopted a mixed-method research design and presents findings for both quantitative data which was collected through an electronic survey and qualitative findings from focus group interviews with three different groups: females, males, and, mixed gender. The population comprised first-year students living in two residences of a selected South African university. The qualitative data was analysed through thematic analysis, while the quantitative data was analysed through descriptive statistics and inferential statistics such as Spearman’s Rank correlation was used in the study. In consideration with the transition theory, social learning theory, and student involvement theory. Findings reveal that first-year students join different groups and they encounter both positive and negative experiences. Positive experiences were observed in relation to academic performance and sense of belonging. Negative experiences indicate that peers influence others to adopt anti-social behaviour, experience undue materialistic pressure, have poor class attendance, and depend on peers for decisions. Overall, it is found that academic success depends on students’ interconnectedness, sense of belonging, peer support, acceptance, and recognition. The findings can be utilized to inform practical strategies and policies to empower first-year students to deal productively and progressively with peer pressure within the higher education sector. The study recommends the implementation of a First-year Student orientation programme which is called University 101 that can assist first-year students with better transition to higher education and can increase retention output. The programme should address the crucial areas that will assists the first-year with better transitions such as diversity, well-being, self-esteem, academic excellence and peer pressure.

Small groups of friends—or peer groups—are a central feature of adolescence that contribute to the development of social identity and feelings of self-worth for group members. Additionally, adolescents value music highly and view it as a vital part of their lives. The purpose of this study was to examine and clarify the extent to which adolescents use music as an identity resource in small peer groups. Using Tajfel and Turner’s Social Identity Theory as a framework, I conducted a collective case study to understand (a) the ways in which adolescents use music to form and maintain a peer group, (b) the extent to which peer groups use music for the social categorization and stereotyping of other groups of adolescents, (c) the ways by which adolescents use music associated with their peer group to maintain a positive self-concept, and (d) how the peer group influences members’ enjoyment of music and music participation. I conducted group interviews with three adolescent peer groups that contained 5–8 seventh- and eighth-grade students. The peer group members shared experiences of bonding and socializing as a part of a peer group, and described time spent in their music classes. During the discussions, group members explained the role that music plays in their lives. The group members explained their peer group in the context of the school, describing instances of social categorization and stereotyping, in-group and out-group distinction, and self-concept maintenance made from comparisons to the out-groups. The participants discussed their views on school music courses, advocating for the implementation of new classes that included non-traditional instruments and the inclusion of more popular styles of music. Keywords: social identity, adolescent peer groups, in-group, out-group, social categorization, self-concept, stereotyping, adolescence music preference, positive distinctness

L'approche criminologique de la délinquance du mineur permet de mettre en lumière les facteurs jouant un rôle dans le processus délinquantiel. Si certaines analyses s'attachent à démontrer l'influence déterminante de l'environnement familial sur la délinquance du mineur, ces propos méritent d'être nuancés. La famille est le modèle de socialisation primaire de l'enfant. Un contexte familial, régi des comportements déviants ou une autorité défaillante, entraînerait dès lors des conséquences criminogènes pour l'enfant. Pour autant, celui-ci ne reproduit pas automatiquement le schéma familial et bénéficie d'une intégration sociale.Dès lors, les analyses multifactorielles de la délinquance mettent en évidence l'importance des autres facteurs environnementaux dans le passage à l'acte du mineur, celui-ci évoluant par la rencontre d'agents extérieurs à la famille.L'influence des facteurs tels que l'école et les groupes de pairs peut se manifester de telle sorte que cette hypothèse remettrait en cause la théorie selon laquelle la famille est un facteur déterminant. Si ces analyses se justifient, elles demeurent incomplètes, soulevant alors la question du lien entre la délinquance juvénile et le fonctionnement de la société occidentale. / A criminalogy approach makes it possible to highlight decisive factors of the delinquency process (ou the criminal process). Some analysts aims to prove the importance of familial context on juvenile delinquency although these explanations seems insufficient. Family is the primary socialisation instance and familial background with deviant behaviors and defaulting authority could thus have an impact on juvenile delinquency. One can observe however that children sometimes do not reproduce the family scheme and are socially integrated. Consequently, a multi-factors analysis of delinquency points up the importance of other contextual factors, among them the external agents to the family encounters, in explaining the first acts of delinquency. Influence of factors as education and peer group imply the questioning of the familial background considered as a key factor of juvenile delinquency. If verified, these analysis remain nonetheless an incomplete explanation, while raising the question of the causal relationship between juvenile delinquency and the workings of Western society.

Orientador: Raul Aragão Martins / Banca: Sandra Regina Gimeniz-Paschoal / Banca: Marina Rezende Bazon / Resumo: O uso de álcool e outras drogas por jovens é um tema que provoca debates e preocupações em toda a sociedade. Estudos mostram que o consumo das drogas lícitas predominam em relação às drogas ilícitas e que a substância psicoativa mais consumida entre os jovens é o álcool. Nesse contexto, os adolescentes são os mais vulneráveis ao uso e abuso dessas substâncias e o grupo de pares é considerado um fator de risco para a experimentação, uma vez que exerce pressão e influência no pensar e agir dos adolescentes. Partindo disso, o objetivo desta pesquisa é investigar o consumo de bebidas alcoólicas de estudantes do ensino médio, bem como as características do grupo de pares desses adolescentes. A coleta dos dados foi realizada em uma escola pública estadual da cidade de São José do Rio Preto/SP. Para o levantamento dos dados quantitativos optou-se por adotar instrumentos já utilizados em outros estudos, e para o recolhimento dos dados qualitativos optou-se por criar um instrumento, de acordo com os objetivos propostos. Os resultados do levantamento epidemiológico apontam que 14% dos adolescentes bebem excessivamente, nesse grupo há frequencia maior de adolescentes do sexo masculino, estudando no primeiro e segundo ano do ensino médio, com nível sócioeconomico classificado como classe B, de religião católica e cujo chefe de família possui ensino médio completo. Considerando os resultados da entrevista sobre consumo de álcool, o grupo risco se destaca na quantidade de bebida consumida, com 81,8% apresentando beber excessivo contra 18,2% do grupo geral, em relação à frequência de consumo, 82,6% dos participantes do grupo risco bebem com frequencia de uma vez por semana ou mais, contra 17,4% dos participantes do grupo geral. Os resultados da entrevista sobre grupo de pares indica que a experimentação de bebida alcoólica se dá principalmente com a cerveja, por... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of alcohol and other drugs by teenagers is a situation that provokes debates and it is cause of worry in our society. Studies show that the consumption of legal drugs is predominant over illegal ones and the most consumed psychoactive substance among teenagers is alcohol. Taking into consideration that context, teenagers are the most vulnerable group to the use and abuse of these substances and the peer group is considered a risk factor to experimentation, since it exerts influence over teenagers‟ thinking and acting. The main objective of this study is to investigate the pattern of consumption of alcoholic beverages among high school students and also the characteristics of the peer group of these adolescents. The data were collected in a public state school in the city of São José do Rio Preto, State of São Paulo, Brazil. In order to collect the quantitative data, we have selected instruments that were already adopted by other studies and for the qualitative data collect, we decided to develop an instrument in accordance with the proposed objectives. Results show that 14% of the teenagers drink excessively and most part of them are male, studying in the first or second year of high school, classified, in the social economical class, as class B, catholic and the head of the family has a high school diploma. Results from the interview show that the risk group stands out in the amount of alcohol consumed, 81.8% presented excessive drinking against 18.2% in the general group. In relation to the frequency of use, 82.6% from the risk group drink once o more a week, against 17.4% in the general group. Results from the peer group interview show that alcoholic beverage experimentation takes place in the presence of family members with beer and when the teenagers are about 12 years old. The use of alcoholic beverage among the interviewed teenagers predominantly takes place... (Complete abstract click electronic access below) / Mestre

published_or_final_version / Education / Master / Master of Education

Made available in DSpace on 2014-06-11T19:24:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-17Bitstream added on 2014-06-13T20:13:26Z : No. of bitstreams: 1 silva_ia_me_mar.pdf: 451612 bytes, checksum: cb71cf94bf867d02d20ae47393f6e0c6 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O uso de álcool e outras drogas por jovens é um tema que provoca debates e preocupações em toda a sociedade. Estudos mostram que o consumo das drogas lícitas predominam em relação às drogas ilícitas e que a substância psicoativa mais consumida entre os jovens é o álcool. Nesse contexto, os adolescentes são os mais vulneráveis ao uso e abuso dessas substâncias e o grupo de pares é considerado um fator de risco para a experimentação, uma vez que exerce pressão e influência no pensar e agir dos adolescentes. Partindo disso, o objetivo desta pesquisa é investigar o consumo de bebidas alcoólicas de estudantes do ensino médio, bem como as características do grupo de pares desses adolescentes. A coleta dos dados foi realizada em uma escola pública estadual da cidade de São José do Rio Preto/SP. Para o levantamento dos dados quantitativos optou-se por adotar instrumentos já utilizados em outros estudos, e para o recolhimento dos dados qualitativos optou-se por criar um instrumento, de acordo com os objetivos propostos. Os resultados do levantamento epidemiológico apontam que 14% dos adolescentes bebem excessivamente, nesse grupo há frequencia maior de adolescentes do sexo masculino, estudando no primeiro e segundo ano do ensino médio, com nível sócioeconomico classificado como classe B, de religião católica e cujo chefe de família possui ensino médio completo. Considerando os resultados da entrevista sobre consumo de álcool, o grupo risco se destaca na quantidade de bebida consumida, com 81,8% apresentando beber excessivo contra 18,2% do grupo geral, em relação à frequência de consumo, 82,6% dos participantes do grupo risco bebem com frequencia de uma vez por semana ou mais, contra 17,4% dos participantes do grupo geral. Os resultados da entrevista sobre grupo de pares indica que a experimentação de bebida alcoólica se dá principalmente com a cerveja, por... / The use of alcohol and other drugs by teenagers is a situation that provokes debates and it is cause of worry in our society. Studies show that the consumption of legal drugs is predominant over illegal ones and the most consumed psychoactive substance among teenagers is alcohol. Taking into consideration that context, teenagers are the most vulnerable group to the use and abuse of these substances and the peer group is considered a risk factor to experimentation, since it exerts influence over teenagers‟ thinking and acting. The main objective of this study is to investigate the pattern of consumption of alcoholic beverages among high school students and also the characteristics of the peer group of these adolescents. The data were collected in a public state school in the city of São José do Rio Preto, State of São Paulo, Brazil. In order to collect the quantitative data, we have selected instruments that were already adopted by other studies and for the qualitative data collect, we decided to develop an instrument in accordance with the proposed objectives. Results show that 14% of the teenagers drink excessively and most part of them are male, studying in the first or second year of high school, classified, in the social economical class, as class B, catholic and the head of the family has a high school diploma. Results from the interview show that the risk group stands out in the amount of alcohol consumed, 81.8% presented excessive drinking against 18.2% in the general group. In relation to the frequency of use, 82.6% from the risk group drink once o more a week, against 17.4% in the general group. Results from the peer group interview show that alcoholic beverage experimentation takes place in the presence of family members with beer and when the teenagers are about 12 years old. The use of alcoholic beverage among the interviewed teenagers predominantly takes place... (Complete abstract click electronic access below)

The aim of this study was to get a greater understanding of children´s approach to each other in the after school center. We used a qualitative method consisting of interviews to collect the material to our study. We interviewed five educators that worked in the after school center and focused on their child perspective. The outset for our study was a gender perspective as well as an intersectional perspective. In recent years gender norms have got a lot of attention in media and The National Agency for Education (Skolverket) has come up with policydocuments that intend to make the schools a more equal and accepting place. In our examination we asked the educators about their view on gender- intersectional areas and how they have changed and developed in the last few years. The result in our study showed that it has been a change in equality and gender norm areas at the after school center. According to the educators, the schools have become a more accepting environment and the schools work a lot with having the children to form their identities and that they should be able to be themselves. Another result of our study was that boys and girls play with each other more nowadays than they did before. The educators think that this is because it is more accepted to break and question the gender patterns. Group pressure among children has according to the educators a large role in the selection of friends, games, activities and who should be the leader of the peer group. / Syftet med vår studie var att få en förståelse för barns förhållningssätt till varandra på fritidshemmet. För att samla in empirin till vår studie använde vi oss av en kvalitativ metod i form av intervjuer. Vi intervjuade fem pedagoger som arbetar på fritidshemmet och utgick från deras barnperspektiv. Vår studie utgick från ett genus- och intersektionellt perspektiv. Genusnormer har på senare år fått mycket uppmärksamhet i media samt att Skolverket har utformat styrdokumenten för att skolorna ska sträva efter en jämställd och accepterande skolmiljö. I vår studie frågade vi pedagogerna om deras syn på hur genus och intersektionella områden har utvecklats och ändrats i skolans värld under de senaste åren. Utifrån vår studie blev resultatet att det har skett en förändring när det kommer till jämställdhet och genusnormerna på fritidshemmet. Skolan har blivit en mer accepterande miljö och pedagogerna vi intervjuade menar att man arbetar mycket med att eleverna ska få forma sina identiteter och kunna vara sig själva. Vi kom även fram till att pojkar och flickor leker mer tillsammans nu än för några år sedan. Enligt pedagogerna har det att göra med att det är mer okej nu än då att bryta och ifrågasätta genusmönster. Grupptrycket bland barnen spelar enligt pedagogerna en stor roll i val av kamrater, lek, aktivitet och vem som ska vara ledare i kamratgruppen.