Context-awareness privacy in data communications

Internet users consume online targeted advertising based on information collected about them and voluntarily share personal information in social networks. Sensor information and data from smart-phones is collected and used by applications, sometimes in unclear ways. As it happens today with smartphones, in the near future sensors will be shipped in all types of connected devices, enabling ubiquitous information gathering from the physical environment, enabling the vision of Ambient Intelligence. The value of gathered data, if not obvious, can be harnessed through data mining techniques and put to use by enabling personalized and tailored services as well as business intelligence practices, fueling the digital economy. However, the ever-expanding information gathering and use undermines the privacy conceptions of the past. Natural social practices of managing privacy in daily relations are overridden by socially-awkward communication tools, service providers struggle with security issues resulting in harmful data leaks, governments use mass surveillance techniques, the incentives of the digital economy threaten consumer privacy, and the advancement of consumergrade data-gathering technology enables new inter-personal abuses. A wide range of fields attempts to address technology-related privacy problems, however they vary immensely in terms of assumptions, scope and approach. Privacy of future use cases is typically handled vertically, instead of building upon previous work that can be re-contextualized, while current privacy problems are typically addressed per type in a more focused way. Because significant effort was required to make sense of the relations and structure of privacy-related work, this thesis attempts to transmit a structured view of it. It is multi-disciplinary - from cryptography to economics, including distributed systems and information theory - and addresses privacy issues of different natures. As existing work is framed and discussed, the contributions to the state-of-theart done in the scope of this thesis are presented. The contributions add to five distinct areas: 1) identity in distributed systems; 2) future context-aware services; 3) event-based context management; 4) low-latency information flow control; 5) high-dimensional dataset anonymity. Finally, having laid out such landscape of the privacy-preserving work, the current and future privacy challenges are discussed, considering not only technical but also socio-economic perspectives.

BUILDING EFFICIENT AND COST-EFFECTIVE CLOUD-BASED BIG DATA MANAGEMENT SYSTEMS

In today’s big data world, data is being produced in massive volumes, at great velocity and from a variety of different sources such as mobile devices, sensors, a plethora of small devices hooked to the internet (Internet of Things), social networks, communication networks and many others. Interactive querying and large-scale analytics are being increasingly used to derive value out of this big data. A large portion of this data is being stored and processed in the Cloud due the several advantages provided by the Cloud such as scalability, elasticity, availability, low cost of ownership and the overall economies of scale. There is thus, a growing need for large-scale cloud-based data management systems that can support real-time ingest, storage and processing of large volumes of heterogeneous data. However, in the pay-as-you-go Cloud environment, the cost of analytics can grow linearly with the time and resources required. Reducing the cost of data analytics in the Cloud thus remains a primary challenge. In my dissertation research, I have focused on building efficient and cost-effective cloud-based data management systems for different application domains that are predominant in cloud computing environments. In the first part of my dissertation, I address the problem of reducing the cost of transactional workloads on relational databases to support database-as-a-service in the Cloud. The primary challenges in supporting such workloads include choosing how to partition the data across a large number of machines, minimizing the number of distributed transactions, providing high data availability, and tolerating failures gracefully. I have designed, built and evaluated SWORD, an end-to-end scalable online transaction processing system, that utilizes workload-aware data placement and replication to minimize the number of distributed transactions that incorporates a suite of novel techniques to significantly reduce the overheads incurred both during the initial placement of data, and during query execution at runtime. In the second part of my dissertation, I focus on sampling-based progressive analytics as a means to reduce the cost of data analytics in the relational domain. Sampling has been traditionally used by data scientists to get progressive answers to complex analytical tasks over large volumes of data. Typically, this involves manually extracting samples of increasing data size (progressive samples) for exploratory querying. This provides the data scientists with user control, repeatable semantics, and result provenance. However, such solutions result in tedious workflows that preclude the reuse of work across samples. On the other hand, existing approximate query processing systems report early results, but do not offer the above benefits for complex ad-hoc queries. I propose a new progressive data-parallel computation framework, NOW!, that provides support for progressive analytics over big data. In particular, NOW! enables progressive relational (SQL) query support in the Cloud using unique progress semantics that allow efficient and deterministic query processing over samples providing meaningful early results and provenance to data scientists. NOW! enables the provision of early results using significantly fewer resources thereby enabling a substantial reduction in the cost incurred during such analytics. Finally, I propose NSCALE, a system for efficient and cost-effective complex analytics on large-scale graph-structured data in the Cloud. The system is based on the key observation that a wide range of complex analysis tasks over graph data require processing and reasoning about a large number of multi-hop neighborhoods or subgraphs in the graph; examples include ego network analysis, motif counting in biological networks, finding social circles in social networks, personalized recommendations, link prediction, etc. These tasks are not well served by existing vertex-centric graph processing frameworks whose computation and execution models limit the user program to directly access the state of a single vertex, resulting in high execution overheads. Further, the lack of support for extracting the relevant portions of the graph that are of interest to an analysis task and loading it onto distributed memory leads to poor scalability. NSCALE allows users to write programs at the level of neighborhoods or subgraphs rather than at the level of vertices, and to declaratively specify the subgraphs of interest. It enables the efficient distributed execution of these neighborhood-centric complex analysis tasks over largescale graphs, while minimizing resource consumption and communication cost, thereby substantially reducing the overall cost of graph data analytics in the Cloud. The results of our extensive experimental evaluation of these prototypes with several real-world data sets and applications validate the effectiveness of our techniques which provide orders-of-magnitude reductions in the overheads of distributed data querying and analysis in the Cloud.

Comunicação em MOOC: estratégias e recursos comunicacionais adotados em cursos MOOC

A comunicação é essencial para a vida em sociedade. Na atualidade, com o desenvolvimento de novas formas e possibilidades tecnológicas a comunicação se faz presente também no âmbito educacional utilizando as Tecnologias da Informação e Comunicação (TIC) para atender às exigências sociais e educativas. No caso da educação on-line, os MOOC – Massive Open Online Courses, vêm ganhando destaque e constituem um modelo recente de educação e formação, com a possibilidade de democratização e acesso ao conhecimento e à informação, disponível a um número cada vez maior de pessoas. Neste sentido, o objetivo deste estudo é o de analisar as estratégias e recursos comunicacionais utilizados em cursos MOOC, visando elaborar diretrizes a ter em conta na construção de um curso desta natureza. Para tal, optou-se por uma investigação qualitativa, de natureza exploratória-descritiva, em que a revisão bibliográfica e a construção e aplicação de um modelo de análise dos recursos e estratégias comunicacionais utilizados nos cursos ofertados em plataformas MOOC, integram a metodologia do estudo. Como principais resultados destacamos que os vídeos e fóruns são os recursos mais utilizados nos cursos analisados, observando-se uma tendência de práticas mais empiristas e tradicionais, há pouca utilização de recursos lúdicos e uma ausência do uso de redes sociais como recurso comunicacional. Para além disso, não é utilizada a avaliação dos cursos pelos alunos e predominam as estratégias avaliativas de escolha múltipla. Visando compartilhar as experiências e reflexões advindas desta pesquisa, são apresentadas, ao final, recomendações que podem contribuir para a elaboração de cursos MOOC.

Capital social e ações conjuntas: um estudo de caso no arranjo produtivo local de vinhos de altitude catarinense

The general goal of this study was to analyze the relations between the agents’ social capital and joint actions developed by the Cluster of wine produced at the high altitudes of Santa Catarina. This group is made up of 43 agents: one governing agent, 26 support agents and 16 winemakers. This descriptive and exploratory study uses data from qualitative and quantitative approaches. During the exploratory phase, a documental analysis was carried out, as well as semi-structured interviews. The data collection tool used to gather information concerning the social capital and joint actions was the semi-structured questionnaire, and this data gathering was conducted through field research using a structured interview with the selected agents from November 16 to November 26, 2015. The results of this study show a good social capital, which reflects on the joint actions done by the agents. Among the variables of social capital, trust shows a great level among the Cluster agents, followed by good levels concerning commitment and involvement, information share, rules and sanctions, horizontality and authority and improvement. As a result, it has created a nice level of involvement and effectiveness of joint actions, highlighting events organization, joint participation at fairs and events, marketing campaigns, development of products and processes, and human resources improvement. There is a small group of agents who show a strong social capital and a proper environment to expand this capital throughout the network. However, the evaluation concerning reciprocity and density represents only one third of the possibilities of this group, and it happens especially because of the geographical distance between the agents who are part of the Cluster. The main limitation of this study was the trouble trying to map the whole agent group before applying the questionnaires and identifying the responsible people in each of the support agents to inform everything correctly. It is suggested that these questionnaires be carried out with other Clusters as well as in the future in order to have a temporal assessment of this study.

O processo de organização social do Grupo Herança Viva de Chapecó-SC e suas estratégias de ação conjunta

The consequences resulting from economic modernization model generated social and environmental imbalances, resulting in the exclusion and social isolation, perceived consequences in the agricultural sector. When studying social organizations, tends to see how they keep their forward cooperation processes all a company incorporated by the appreciation of individualism and competition. The overall objective for this research was to analyze the organizational dynamics of Agroecology Group Heritage Viva Chapecó, Santa Catarina, in order to identify the strengths and threats and collaborate in this way for preparation of action strategies for sustainability. The selected group is based on the principles of agroecology for the conduct of their agricultural production systems, avoiding the use of agrochemicals, proven through the use of participatory certification seal Ecovida Network, and the products sold mainly in street fairs in the city of chapecó. To fulfill such a proposal were consulted the minutes of meetings and questionnaires with farmers to assess the dynamics of cooperation among its members, through the understanding of their social capital and social network analysis (SNA). To extend the study of the group and its members was adopted methodological approach of action research where activities were developed to identify strengths and weaknesses and contribute to its organizational restructuring, resulting in the construction, carried out by farmers, the guiding principles of the Living Heritage Group will contribute to the decision-making and strengthen their identity. The survey also brought the group is inserted in the Social Transition Agroecology therefore change the current paradigm is not inserted only in the alternative model of production, but in the form of organization of social actors and their role in the marketing process of their products, in discussing the scenario of food supply chains.

Las posibilidades de internet en la reconfiguración de la red social primaria del adulto mayor, fracturada por efecto de la migración* El caso de los adultos mayores con parientes migrantes en 6 municipios del departamento del Quindío

El presente artículo muestra cómo Internet se convierte en una herramienta de comunicación importante para reconfigurar la red social primaria del adulto mayor, fracturada por efecto de la migración. En la investigación que le da origien, se pudo constatar que hoy esta red se encuentra dividida en red primaria natural, conformada por los parientes y amigos con los que comparte el día a día, y red primaria virtual, integrada por los parientes migrantes. El escrito centra su interés en presentar las características de la red primaria virtual en la que el adulto mayor se vio impelido a participar para satisfacer sus necesidades comunicacionales. Esta red cumple la función de mantener, pero no de extender, su red social primaria. Los resultados dan cuenta de 4 aspectos: las competencias digitales desarrolladas por el adulto mayor, la estructura, las funciones y los atributos de vínculo de la red primaria virtual. Para ello se acudió a autores como Cabrera, Castell; Madarriaga, Abello & Sierra; Narváez A.; Soto, Navarro & Sánchez; Tovar & Villarraga. La investigación fue de tipo etnográfico, con enfoque cualitativo. Se aplicaron entrevistas semi-estructuradas. Para el tratamiento de la información se utilizó la teoría Fundamentad, de Strauss & Corbin (2002).

Usos político-partidistas en cuentas de Twitter de administraciones públicas

Introducción: La comunicación institucional y la comunicación política deberían tener cauces de difusión separados pero, adoptando la hipótesis de la normalización, en las redes sociales también se refleja la tendencia al indebido uso partidista de los canales institucionales. Metodología: Este estudio analiza las publicaciones en Twitter de 40 cuentas institucionales españolas distribuidas equitativamente entre cuatro niveles territoriales (estatal, autonómico, provincial y local). Se trata de una investigación cualitativa con un método exploratorio en el que se ha empleado fundamentalmente el análisis de contenido. Resultados y conclusiones: Los resultados verifican la hipótesis de que se están dando usos propagandísticos y partidistas desde estas cuentas institucionales con una decena de tendencias que reflejan una gran preocupación por la proyección de los políticos en tanto que agentes de un partido. Por tanto, se consolida en este nuevo canal la confusión de estos dos planos, ya advertida en investigaciones previas con respecto a las salas de prensa online de una institución (García Orosa y Vázquez Sande, 2012).

Cultural citizenship and its implications for citizenship education: Chinese university students’ civic experience in relation to mass media and the university citizenship curriculum

A growing body of research has argued that university citizenship curricula are inefficient in promoting civic participation, while there is a tendency towards a broader citizenship understanding and new forms of civic engagements and citizenship learning in everyday life. The notion of cultural citizenship in this thesis concentrates on media practices’ relation to civic expression and civic engagement. This research thus argues that not enough attention has been paid to the effects of citizenship education policy on students and students’ active citizenship learning in China. This thesis examines the civic experience of university students in China in the parallel contexts of widespread adoption of mass media and of university citizenship education courses, which have been explicitly mandatory for promoting civic morality education in Chinese universities since 2007. This research project raises significant questions about the meditating influences of these two contexts on students’ perceptions of civic knowledge and civic participation, with particular interest to examine whether and how the notion of cultural citizenship could be applied in the Chinese context and whether it could provide certain implications for citizenship education in China. University students in one university in Beijing contributed to this research by providing both quantitative and qualitative data collected from mixed-methods research. 212 participants contributed to the questionnaire data collection and 12 students took part in interviews. Guided by the theoretical framework of cultural citizenship, a central focus of this study is to explore whether new forms of civic engagement and civic learning and a new direction of citizenship understanding can be identified among university students’ mass media use. The study examines the patterns of students’ mass media use and its relationship to civic participation, and also explores the ways in which mass media shape students and how they interact and perform through the media use. In addition, this study discusses questions about how national context, citizenship tradition and civic education curricula relate to students’ civic perceptions, civic participation and civic motivation in their enactment of cultural citizenship. It thus tries to provide insights and identify problems associated with citizenship courses in Chinese universities. The research finds that Chinese university students can also identify civic issues and engage in civic participation through the influence of mass media, thus indicating the application of cultural citizenship in the wider higher education arena in China. In particular, the findings demonstrate that students’ citizenship knowledge has been influenced by their entertainment experiences with TV programs, social networks and movies. However, the study argues that the full enactment of cultural citizenship in China is conditional with regards to characteristics related to two prerequisites: the quality of participation and the influence of the public sphere in the Chinese context. Most students in the study are found to be inactive civic participants in their everyday lives, especially in political participation. Students express their willingness to take part in civic activities, but they feel constrained by both the current citizenship education curriculum in universities and the strict national policy framework. They mainly choose to accept ideological and political education for the sake of personal development rather than to actively resist it, however, they employ creative ways online to express civic opinions and conduct civic discussion. This can be conceptualised as the cultural dimension of citizenship observed from students who are not passively prescribed by traditional citizenship but who have opportunities to build their own civic understanding in everyday life. These findings lead to the conclusion that the notion of cultural citizenship not only provides a new mode of civic learning for Chinese students but also offers a new direction for configuring citizenship in China. This study enriches the existing global literature on cultural citizenship by providing contemporary evidence from China which is a developing democratic country, as well as offering useful information for Chinese university practitioners, policy makers and citizenship researchers on possible directions for citizenship understanding and citizenship education. In particular, it indicates that it is important for efforts to be made to generate a culture of authentic civic participation for students in the university as well as to promote the development of the public sphere in the community and the country generally.

Structured Approaches for Exploring Interpersonal Relationships in Natural Language Text

Human relationships have long been studied by scientists from domains like sociology, psychology, literature, etc. for understanding people's desires, goals, actions and expected behaviors. In this dissertation we study inter-personal relationships as expressed in natural language text. Modeling inter-personal relationships from text finds application in general natural language understanding, as well as real-world domains such as social networks, discussion forums, intelligent virtual agents, etc. We propose that the study of relationships should incorporate not only linguistic cues in text, but also the contexts in which these cues appear. Our investigations, backed by empirical evaluation, support this thesis, and demonstrate that the task benefits from using structured models that incorporate both types of information. We present such structured models to address the task of modeling the nature of relationships between any two given characters from a narrative. To begin with, we assume that relationships are of two types: cooperative and non-cooperative. We first describe an approach to jointly infer relationships between all characters in the narrative, and demonstrate how the task of characterizing the relationship between two characters can benefit from including information about their relationships with other characters in the narrative. We next formulate the relationship-modeling problem as a sequence prediction task to acknowledge the evolving nature of human relationships, and demonstrate the need to model the history of a relationship in predicting its evolution. Thereafter, we present a data-driven method to automatically discover various types of relationships such as familial, romantic, hostile, etc. Like before, we address the task of modeling evolving relationships but don't restrict ourselves to two types of relationships. We also demonstrate the need to incorporate not only local historical but also global context while solving this problem. Lastly, we demonstrate a practical application of modeling inter-personal relationships in the domain of online educational discussion forums. Such forums offer opportunities for its users to interact and form deeper relationships. With this view, we address the task of identifying initiation of such deeper relationships between a student and the instructor. Specifically, we analyze contents of the forums to automatically suggest threads to the instructors that require their intervention. By highlighting scenarios that need direct instructor-student interactions, we alleviate the need for the instructor to manually peruse all threads of the forum and also assist students who have limited avenues for communicating with instructors. We do this by incorporating the discourse structure of the thread through latent variables that abstractly represent contents of individual posts and model the flow of information in the thread. Such latent structured models that incorporate the linguistic cues without losing their context can be helpful in other related natural language understanding tasks as well. We demonstrate this by using the model for a very different task: identifying if a stated desire has been fulfilled by the end of a story.

On-light: optical social network

Social networks are a recent phenomenon of communication, with a high prevalence of young users. This concept serves as a motto for a multidisciplinary project, which aims to create a simple communication network, using light as the transmission medium. Mixed team, composed by students from secondary and higher education schools, are partners on the development of an optical transceiver. A LED lamp array and a small photodiode are the optical transmitter and receiver, respectively. Using several transceivers aligned with each other, this con guration creates a ring communication network, enabling the exchange of messages between users. Through this project, some concepts addressed in physics classes from secondary schools (e.g. photoelectric phenomena and the properties of light) are experimentally veri ed and used to communicate, in a classroom or a laboratory.

Principais fatores motivacionais na compra de livros de ficção

O presente projeto de Mestrado assenta no estudo dos principais fatores motivacionais na compra de livros de ficção, aprofundando a dicotomia uso próprio versus oferta, englobando duas perspetivas complementares: a sustentação bibliográfica e uma pesquisa quantitativa que foi concretizada através da distribuição de um inquérito por questionário, em formato digital, que permitiu obter 487 respostas válidas e completas. Os dados obtidos foram tratados no SPSS (Statistical Package for the Social Sciences), utilizando análises descritivas, que foram complementadas com técnicas de inferência estatística. Os resultados permitiram concluir que, apesar de homens e mulheres oferecerem um número idêntico de livros, as mulheres compram e leem mais. Além disso, cerca de um terço dos livros comprados destina-se a oferta. Ficou ainda provado que a interação com os autores nas redes sociais apresenta uma associação positiva com a importância atribuida a esse fator na hora de comprar o(s) livro(s). As mulheres são mais sensíveis às “Políticas de Marketing” (Atendimento Personalizado; Facilidade de Pagamento; Local com Cartão de Fidelização; Preços e Descontos; Elevada quantidade de livros), enquanto critérios de seleção do local de compra. Importa referir que a compra é concretizada de forma menos impulsiva quando o livro é para oferta. Os atributos da capa mais relevantes no processo de decisão de compra são o “Título” e a “Sinopse”. Contudo, os diferentes fatores da capa estudados não apresentam diferenças significativas na compra para uso próprio comparativamente à oferta, no que respeita à sua importância. “Autores com prémios literários” e “Nobel” e “Ser uma novidade” (livro) são outros fatores (não da capa) que apresentam diferenças significativas favoráveis à compra para oferta. Por outro lado, “Recomendação de Amigos e Familiares” e “Presença/Ligação/Interação com o Autor nas redes sociais” são mais favoráveis à compra para uso próprio. As conclusões são relevantes para enquadrar as preferências dos consumidores, possibilitando aos profissionais do marketing algumas referências para definir estratégias que respondam às suas necessidades e ambições. Além disso, ao explorar a dimensão dos submercados (Uso próprio versus Oferta), será possível ir ao encontro das exigências dos compradores, tornando a subjetividade da aquisição/utilização numa ferramenta eficaz da própria idealização e personalização dos livros, permitindo conceber e implementar ideias empreendedoras que visem estimular a compra e, consequentemente, melhorar os hábitos de leitura de todos os portugueses.

Computational Analysis of Intelligent Agents: Social and Strategic Settings

The central motif of this work is prediction and optimization in presence of multiple interacting intelligent agents. We use the phrase `intelligent agents' to imply in some sense, a `bounded rationality', the exact meaning of which varies depending on the setting. Our agents may not be `rational' in the classical game theoretic sense, in that they don't always optimize a global objective. Rather, they rely on heuristics, as is natural for human agents or even software agents operating in the real-world. Within this broad framework we study the problem of influence maximization in social networks where behavior of agents is myopic, but complication stems from the structure of interaction networks. In this setting, we generalize two well-known models and give new algorithms and hardness results for our models. Then we move on to models where the agents reason strategically but are faced with considerable uncertainty. For such games, we give a new solution concept and analyze a real-world game using out techniques. Finally, the richest model we consider is that of Network Cournot Competition which deals with strategic resource allocation in hypergraphs, where agents reason strategically and their interaction is specified indirectly via player's utility functions. For this model, we give the first equilibrium computability results. In all of the above problems, we assume that payoffs for the agents are known. However, for real-world games, getting the payoffs can be quite challenging. To this end, we also study the inverse problem of inferring payoffs, given game history. We propose and evaluate a data analytic framework and we show that it is fast and performant.

Eventos Terroristas e Redes Sociais

Este estudo pretende ser um contributo para explicar de que forma a experiência dos utilizadores da internet influência a curiosidade e a atenção que os mesmos têm pela leitura de notícias online sobre eventos terroristas. Analisa-se também a forma como a experiência dos utilizadores da internet influência duma forma direta e indireta a receção de mensagens eletrónicas (eWOM – electronic word-of-mouth). Foi utilizada uma amostragem de 200 inquiridos, maioritariamente Portugueses. Os dados foram analisados recorrendo aos softwares estatísticos SPSS 21 e Lisrel 8.8.Os resultados realçam a importância do consumo e o encaminhamento de notícias sobre eventos terroristas e, surpreendentemente a influência negativa do eWOM sobre a partilha de notícias na internet. Futuramente, as organizações devem aumentar e dar maior notoriedade à credibilidade das informações sobre eventos terroristas, isto terá implicações positivas na atenção e na curiosidade prestada pelos consumidores acerca de conteúdos sobre terrorismo.

Cogestion des ressources naturelles : une approche structurale pour quantifier la contribution des réseaux d'acteurs à la résilience des systèmes socio-écologiques

Alors que les activités anthropiques font basculer de nombreux écosystèmes vers des régimes fonctionnels différents, la résilience des systèmes socio-écologiques devient un problème pressant. Des acteurs locaux, impliqués dans une grande diversité de groupes — allant d’initiatives locales et indépendantes à de grandes institutions formelles — peuvent agir sur ces questions en collaborant au développement, à la promotion ou à l’implantation de pratiques plus en accord avec ce que l’environnement peut fournir. De ces collaborations répétées émergent des réseaux complexes, et il a été montré que la topologie de ces réseaux peut améliorer la résilience des systèmes socio-écologiques (SSÉ) auxquels ils participent. La topologie des réseaux d’acteurs favorisant la résilience de leur SSÉ est caractérisée par une combinaison de plusieurs facteurs : la structure doit être modulaire afin d’aider les différents groupes à développer et proposer des solutions à la fois plus innovantes (en réduisant l’homogénéisation du réseau), et plus proches de leurs intérêts propres ; elle doit être bien connectée et facilement synchronisable afin de faciliter les consensus, d’augmenter le capital social, ainsi que la capacité d’apprentissage ; enfin, elle doit être robuste, afin d’éviter que les deux premières caractéristiques ne souffrent du retrait volontaire ou de la mise à l’écart de certains acteurs. Ces caractéristiques, qui sont relativement intuitives à la fois conceptuellement et dans leur application mathématique, sont souvent employées séparément pour analyser les qualités structurales de réseaux d’acteurs empiriques. Cependant, certaines sont, par nature, incompatibles entre elles. Par exemple, le degré de modularité d’un réseau ne peut pas augmenter au même rythme que sa connectivité, et cette dernière ne peut pas être améliorée tout en améliorant sa robustesse. Cet obstacle rend difficile la création d’une mesure globale, car le niveau auquel le réseau des acteurs contribue à améliorer la résilience du SSÉ ne peut pas être la simple addition des caractéristiques citées, mais plutôt le résultat d’un compromis subtil entre celles-ci. Le travail présenté ici a pour objectifs (1), d’explorer les compromis entre ces caractéristiques ; (2) de proposer une mesure du degré auquel un réseau empirique d’acteurs contribue à la résilience de son SSÉ ; et (3) d’analyser un réseau empirique à la lumière, entre autres, de ces qualités structurales. Cette thèse s’articule autour d’une introduction et de quatre chapitres numérotés de 2 à 5. Le chapitre 2 est une revue de la littérature sur la résilience des SSÉ. Il identifie une série de caractéristiques structurales (ainsi que les mesures de réseaux qui leur correspondent) liées à l’amélioration de la résilience dans les SSÉ. Le chapitre 3 est une étude de cas sur la péninsule d’Eyre, une région rurale d’Australie-Méridionale où l’occupation du sol, ainsi que les changements climatiques, contribuent à l’érosion de la biodiversité. Pour cette étude de cas, des travaux de terrain ont été effectués en 2010 et 2011 durant lesquels une série d’entrevues a permis de créer une liste des acteurs de la cogestion de la biodiversité sur la péninsule. Les données collectées ont été utilisées pour le développement d’un questionnaire en ligne permettant de documenter les interactions entre ces acteurs. Ces deux étapes ont permis la reconstitution d’un réseau pondéré et dirigé de 129 acteurs individuels et 1180 relations. Le chapitre 4 décrit une méthodologie pour mesurer le degré auquel un réseau d’acteurs participe à la résilience du SSÉ dans lequel il est inclus. La méthode s’articule en deux étapes : premièrement, un algorithme d’optimisation (recuit simulé) est utilisé pour fabriquer un archétype semi-aléatoire correspondant à un compromis entre des niveaux élevés de modularité, de connectivité et de robustesse. Deuxièmement, un réseau empirique (comme celui de la péninsule d’Eyre) est comparé au réseau archétypique par le biais d’une mesure de distance structurelle. Plus la distance est courte, et plus le réseau empirique est proche de sa configuration optimale. La cinquième et dernier chapitre est une amélioration de l’algorithme de recuit simulé utilisé dans le chapitre 4. Comme il est d’usage pour ce genre d’algorithmes, le recuit simulé utilisé projetait les dimensions du problème multiobjectif dans une seule dimension (sous la forme d’une moyenne pondérée). Si cette technique donne de très bons résultats ponctuellement, elle n’autorise la production que d’une seule solution parmi la multitude de compromis possibles entre les différents objectifs. Afin de mieux explorer ces compromis, nous proposons un algorithme de recuit simulé multiobjectifs qui, plutôt que d’optimiser une seule solution, optimise une surface multidimensionnelle de solutions. Cette étude, qui se concentre sur la partie sociale des systèmes socio-écologiques, améliore notre compréhension des structures actorielles qui contribuent à la résilience des SSÉ. Elle montre que si certaines caractéristiques profitables à la résilience sont incompatibles (modularité et connectivité, ou — dans une moindre mesure — connectivité et robustesse), d’autres sont plus facilement conciliables (connectivité et synchronisabilité, ou — dans une moindre mesure — modularité et robustesse). Elle fournit également une méthode intuitive pour mesurer quantitativement des réseaux d’acteurs empiriques, et ouvre ainsi la voie vers, par exemple, des comparaisons d’études de cas, ou des suivis — dans le temps — de réseaux d’acteurs. De plus, cette thèse inclut une étude de cas qui fait la lumière sur l’importance de certains groupes institutionnels pour la coordination des collaborations et des échanges de connaissances entre des acteurs aux intérêts potentiellement divergents.

Os critérios de gatekeeping que evitam que uma lovebrand se transforme numa hatebrand

A relação marca/consumidor é importante e, atualmente, com a evolução tecnológica e com a disseminação das redes sociais, a sua importância subiu de nível pois o meio online permite que os consumidores estejam mais informados e tenham mais consciência das diversas opções que existem no mercado. Como tal, as marcas aproveitam as redes sociais, tais como o Facebook, para se fazerem notar, para mostrarem o seu lado mais humano e assim estabelecer comunicação com os utilizadores de forma a criar ou manter uma relação mais íntima com o mesmo. Contudo, a liberdade de expressão que existe nas redes sociais nem sempre é favorável às marcas, o que faz com que estas optem por utilizar critérios de gatekeeping para filtrar alguns conteúdos. O que se pretende deste estudo não experimental de tipo exploratório e de método qualitativo, é aferir que critérios de gatekeeping é que são mais suscetíveis de serem utilizados pelas marcas, de forma a evitarem que a relação forte que detêm com o consumidor fique comprometida e manchada pelo ódio e, consequentemente, perceber como é feita a gestão das próprias páginas de Facebook. O objeto do estudo em causa envolve, assim, duas empresas do setor eletrónico que são concorrentes diretas e que têm consumidores muito dedicados e que foram selecionadas através de um método de amostragem não aleatório intencional.