98 research outputs found

    Graphs behind data: A network-based approach to model different scenarios

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    openAl giorno d’oggi, i contesti che possono beneficiare di tecniche di estrazione della conoscenza a partire dai dati grezzi sono aumentati drasticamente. Di conseguenza, la definizione di modelli capaci di rappresentare e gestire dati altamente eterogenei Ăš un argomento di ricerca molto dibattuto in letteratura. In questa tesi, proponiamo una soluzione per affrontare tale problema. In particolare, riteniamo che la teoria dei grafi, e piĂč nello specifico le reti complesse, insieme ai suoi concetti ed approcci, possano rappresentare una valida soluzione. Infatti, noi crediamo che le reti complesse possano costituire un modello unico ed unificante per rappresentare e gestire dati altamente eterogenei. Sulla base di questa premessa, mostriamo come gli stessi concetti ed approcci abbiano la potenzialitĂ  di affrontare con successo molti problemi aperti in diversi contesti. ​Nowadays, the amount and variety of scenarios that can benefit from techniques for extracting and managing knowledge from raw data have dramatically increased. As a result, the search for models capable of ensuring the representation and management of highly heterogeneous data is a hot topic in the data science literature. In this thesis, we aim to propose a solution to address this issue. In particular, we believe that graphs, and more specifically complex networks, as well as the concepts and approaches associated with them, can represent a solution to the problem mentioned above. In fact, we believe that they can be a unique and unifying model to uniformly represent and handle extremely heterogeneous data. Based on this premise, we show how the same concepts and/or approach has the potential to address different open issues in different contexts. ​INGEGNERIA DELL'INFORMAZIONEopenVirgili, Luc

    Social marketing in contexts of uncertainty: An analysis of social capital and health social support in online health communities facing treatment uncertainty

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    For several medical treatments there is considerable scientific and medical uncertainty about the relative benefits and risks they imply. The literature indicates social support as an important factor in health uncertainty management. The concept of social support has gained considerable interest in the areas of behavioral medicine and health psychology research. Despite such interest, it is still not clear how it can be approached in social marketing interventions since there is a lack of conceptual and empirical literature discussing the concept from a social marketing perspective. The present thesis aims to explore how the social support concept can be better approached in social marketing interventions targeting contexts of treatment uncertainty. To attain this objective, first a scoping review of social marketing interventions in the health area operationalizing the concept of social support was undertaken. Results indicated that interventions have operationalized the concept in connection with all the key aspects of social marketing, including behavioral change, consumer research, segmentation and targeting, and exchange, as well as marketing mix and competition. However, the findings also indicated poor conceptualizations of social support and the underreporting of the theoretical rationale for the operationalization of the concept. Second, the study adopted a mixed-methods approach that involved netnography and social network analysis, to examine the nature of online social support, understood as a resource generated through social capital, using two distinct case studies: i) an online forum focused on health discussion about electronic cigarettes; ii) an online forum dedicated to menopausal hormone replacement therapy. Findings indicate that online health communities can be a place for extending the support networks of people facing treatment uncertainty as multiple typologies of peer-to-peer social support are remotely exchanged in the virtual communities. Both online health communities were found to have similar network structures characterized by small-world and scale free properties and reduced levels of reciprocity. Results also indicate that users mostly search for informational types of support in the online health communities and that they can be segmented based on the structural positions they occupy in the networks and patterns of support interaction. However, it was found that the information available in these forums can be subject to imprudent processes of selection by forum participants who try to conform online discussion to suit the forums’ shared and accepted narratives that highlight the benefits of these uncertain treatments, while minimizing the respective risks. From a theoretical perspective, this study has relevant implications for health uncertainty management literature by putting in evidence collective processes of information selection in the online health communities, that can hinder the main objective of these virtual spaces, that is to function as platforms for knowledge acquisition. Second it deepens understanding about the interconnected relations between the concepts of social capital and social support. The study also brings innovation in methods by combining social network analysis and netnography, two naturalistic and online-suited research methods to study online health communities. For practionaires, the results of the study provide significant insights that can be used to program social marketing interventions intended to increase and enhance the quality of social support available in these types of online health communities.Para vĂĄrios tratamentos mĂ©dicos existe considerĂĄvel incerteza mĂ©dica e cientĂ­fica sobre os benefĂ­cios e riscos relativos. A literatura indica o apoio social como um importante fator na gestĂŁo de incertezas na saĂșde. O conceito de apoio social despertou muito interesse nas ĂĄreas de medicina comportamental e psicologia. No entanto, nĂŁo Ă© clara a forma como o conceito pode ser abordado em intervençÔes de marketing social uma vez que existem poucos estudos conceptuais e empĂ­ricos focados neste tĂłpico na literatura de marketing social. A presente tese investiga a forma como o conceito de apoio social pode ser aplicado a contextos caracterizados por incerteza nos tratamentos mĂ©dicos. Para atingir este objetivo, em primeiro lugar procedeu-se a uma revisĂŁo da literatura focada em intervençÔes de marketing social na ĂĄrea da saĂșde que reportam a utilização do conceito de apoio social. Os resultados indicam que as intervençÔes de marketing social analisadas operacionalizaram o conceito de apoio social em conexĂŁo com as dimensĂ”es chave do marketing social, incluindo os princĂ­pios de mudança comportamental, investigação sobre o consumidor, segmentação e targeting, o princĂ­pio do intercĂąmbio, bem como o marketing mix e anĂĄlise da competição. Contudo, tambĂ©m se concluiu que a generalidade das intervençÔes abordam o conceito de forma pouco rigorosa e que nĂŁo reportam o racional teĂłrico para a operacionalização do conceito. Em segundo lugar, o estudo adota uma abordagem mista envolvendo netnografia e anĂĄlise de redes sociais, para examinar a natureza do apoio social virtual, entendido como um recurso gerado atravĂ©s de capital social, em comunidades de saĂșde virtuais sujeitas a incerteza nos tratamentos, usando dois casos de estudo: um fĂłrum online dedicado Ă  discussĂŁo de cigarros eletrĂłnicos e um fĂłrum online focado no tema do tratamento hormonal para mulheres em menopausa. Concluiu-se que estas comunidades online podem servir como um espaço de extensĂŁo Ă s redes de suporte de indivĂ­duos sujeitos a incerteza nos tratamentos uma vez que mĂșltiplas tipologias de apoio social parceiro-a-parceiro sĂŁo prestadas remotamente nas comunidades virtuais. Ambas as comunidades analisadas apresentam uma estrutura de rede semelhante, caracterizada por propriedades de “pequeno-mundo”, propriedades de “escala livre” e reduzidos Ă­ndices de reciprocidade. Os resultados tambĂ©m indicam que a generalidade dos utilizadores procura apoio do tipo informacional nas comunidades e que estes podem ser segmentados tendo por base as posiçÔes estruturais que ocupam nas redes e os respetivos padrĂ”es de apoio social. No entanto, foi igualmente descoberto que a informação disponĂ­vel nestes fĂłruns pode estar sujeita a processos imprudentes de seleção pelos participantes nos fĂłruns, que tentam conformar as discussĂ”es online por forma a servirem as narrativas aceites e amplamente difundidas que realçam os benefĂ­cios destes tratamentos incertos enquanto minimizam os respetivos riscos. Do ponto de vista teĂłrico, este estudo apresenta implicaçÔes importantes para a literatura sobre gestĂŁo de incerteza ao colocar em evidĂȘncia processos coletivos de seleção de informação nas comunidades online que podem prejudicar a função primordial destes espaços online, que Ă© funcionarem como plataformas para a aquisição de conhecimento. Em segundo lugar, o estudo aprofunda o conhecimento sobre as relaçÔes interdependentes entre os conceitos de capital social e apoio social. O estudo tambĂ©m apresenta inovação em termos metodolĂłgicos ao combinar analise se redes sociais com netnografia, duas metodologias naturalistas e perfeitamente adaptadas ao ambiente online, para estudar comunidades de saĂșde online. Para a prĂĄtica, os resultados deste estudo oferecem conhecimentos significativos que podem ser usados para a programação de açÔes de marketing social destinadas a melhorar a qualidade e quantidade do apoio social disponĂ­vel neste tipo de comunidades online

    Coalitions and conflict: A longitudinal analysis of men's politics

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    Fuzzy Techniques for Decision Making 2018

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    Zadeh's fuzzy set theory incorporates the impreciseness of data and evaluations, by imputting the degrees by which each object belongs to a set. Its success fostered theories that codify the subjectivity, uncertainty, imprecision, or roughness of the evaluations. Their rationale is to produce new flexible methodologies in order to model a variety of concrete decision problems more realistically. This Special Issue garners contributions addressing novel tools, techniques and methodologies for decision making (inclusive of both individual and group, single- or multi-criteria decision making) in the context of these theories. It contains 38 research articles that contribute to a variety of setups that combine fuzziness, hesitancy, roughness, covering sets, and linguistic approaches. Their ranges vary from fundamental or technical to applied approaches

    On Anonymizing the Provenance of Collection-Based Workflows

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    We examine in this paper the problem of anonymizing the prove-nance of collection-oriented workflows, in which the constituent modules use and generate sets of data records. Despite their popularity , this kind of workflow has been overlooked in the literature w.r.t privacy. We, therefore, set out in this paper to examine the following questions: How the provenance of a collection-based module can be anonymized? Can lineage information be preserved? Beyond a single module, how can the provenance of a whole work-flow be anonymized? As well as addressing the above questions, we report on evaluation exercises that assess the effectiveness and efficiency of our solution. In particular, we tease apart the parameters that impact the quality of the obtained anonymized provenance information

    Protecting Privacy When Sharing and Releasing Data with Multiple Records per Person

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    This study concerns the risks of privacy disclosure when sharing and releasing a dataset in which each individual may be associated with multiple records. Existing data privacy approaches and policies typically assume that each individual in a shared dataset corresponds to a single record, leading to an underestimation of the disclosure risks in multiple records per person scenarios. We propose two novel measures of privacy disclosure to arrive at a more appropriate assessment of disclosure risks. The first measure assesses individual-record disclosure risk based upon the frequency distribution of individuals’ occurrences. The second measure assesses sensitive-attribute disclosure risk based upon the number of individuals affiliated with a sensitive value. We show that the two proposed disclosure measures generalize the well-known k-anonymity and l-diversity measures, respectively, and work for scenarios with either a single record or multiple records per person. We have developed an efficient computational procedure that integrates the two proposed measures and a data quality measure to anonymize the data with multiple records per person when sharing and releasing the data for research and analytics. The results of the experimental evaluation using real-world data demonstrate the advantage of the proposed approach over existing techniques for protecting privacy while preserving data quality

    Yemeni, Muslim, and Scouse: Ethnicity and Religion, Hybridity and Locality in Contemporary Liverpool

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    British-Yemenis have received little attention, scholarly or otherwise, in the contemporary context of the UK. Similarly, there are few ethnographically-informed studies focusing on contemporary Liverpool despite the region’s rich histories of migration and its numerous diaspora groups. Addressing these gaps, this thesis presents an ethnographic study of contemporary Liverpool-Yemeni life based on fifteen months of fieldwork during 2017 and 2018. The focus is primarily upon the constructions and performances of everyday Liverpool-Yemeni identities among the post-migration generation who continuously negotiate the diasporic tension of ‘roots’ and ‘routes’. Adapting Gerd Baumann’s framework of ‘the multicultural triangle’ to account for dimensions of translocality, Liverpool-Yemenis’ multiple belongings are explored along ethnic, national/local, and religious lines. The key finding of the thesis is that while second-generation Liverpool-Yemenis largely do not mobilise politically as an ethno-national ‘community’ to enact change in the homeland, ‘Yemeniness’ nonetheless retains salience in the production and performances of an aesthetic diaspora, which is rooted in the translocal family beyond the gaze of the institutions of wider society, yet also negotiated alongside multiple other belongings. While subjective ‘Yemeniness’ is rarely politicised, the milieu of L8 with its long history within Liverpool as a multi-ethnic locality provides an important, alternative space of belonging and engagement beyond family networks. In the context of this neighbourhood, processes of organic hybridisation and practices of demotic cosmopolitanism give rise to increasingly confident articulations of ‘Scouse-Yemeniness’. Additionally, Islam and Muslim identifications are more often articulated as inseparable from participants’ subjective ‘Yemeniness’. Yemen and Yemeni culture are instead reclaimed as legitimately ‘Islamic’, particularly against perceived Saudi antagonisms. Islam is also seen to provide a shared, but not de-culturated, form of belonging extending beyond ethnic ties in the multi-ethnic neighbourhood
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