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Pessoas em situação de rua na cidade de São Paulo: itinerários e estratégias na construção de redes sociais e identidades / Homeless people in the city of São Paulo: routes and strategies in the construction of social nets and identitiesGalvani, Debora 01 October 2008 (has links)
Compreende-se que a população em situação de rua, enquanto grupo social, transita entre zonas de vulnerabilidade e desfiliação conforme definidas por Robert Castel, pois está freqüentemente submetida à ausência de emprego ou a trabalhos temporários e a uma trajetória marcada por rupturas. Em muitos casos, a rede de assistência é o elemento fundamental na sua organização cotidiana. A heterogeneidade deste grupo social constitui uma premissa neste estudo. No interior de tal diversidade, foram identificados grupos e pessoas que pareciam proporcionar referência para a discussão de formas endógenas/internas (e de auto-organização) de superação dessa condição. Assim, meu interesse neste estudo esteve voltado para a compreensão dos processos contrários ao movimento de dissociação social, além de abranger o desenvolvimento de estratégias como a criação de redes sociais e o fortalecimento de identidades. Trata-se de pesquisa etnográfica, envolvendo convívio prolongado com o grupo social estudado e aproximação com seus modos de vida. A coleta de dados foi realizada por doze meses em 2006, com observação de campo, entrevistas e coleta de documentos. Foram realizadas entrevistas com cinco colaboradores e visitas aos seus circuitos e \"pedaços\" pela cidade. Os critérios para inclusão dos colaboradores da pesquisa foram: estar inserido em programa de moradia; participar de organização política (movimentos sociais específicos); integrar redes de relações de caráter religioso; integrar circuitos ligados a arte e cultura; utilizar serviços da rede assistencial como recurso complementar para organização de seu cotidiano; possuir formas de geração de renda. Além destas dimensões, que sugerem diferentes formas de participação social, foi critério de seleção o colaborador estar ou ter vivido em situação de rua por mais de dois anos. A análise foi realizada em duas perspectivas. Uma refere-se à reconstituição da história de vida de cada colaborador, com o objetivo central de mostrar suas redes de interdependência, as quais transcendem os circuitos assistenciais, e de discutir sua singularidade no processo de construção de identidades capazes de ressignificar e dar historicidade à experiência da situação de rua. Outra perspectiva de análise foi partir da percepção de eixos e temáticas comuns que contribuem para repensar possíveis conexões, propostas assistenciais e outras redes de proximidade, as quais foram trabalhadas nos itens relativos a recurso à assistência social, participação política e educação. Observou-se a construção de movimentos opostos à desfiliação cujos processos significam a construção de identidades diferenciadas que tornam relativo e contextualizado o lugar atribuído à pessoa em situação de rua, geralmente associado a fracassos e à dependência dos serviços. Há, porém, necessidade de se produzir situações preventivas e alternativas coletivas. O estudo das redes sociais dentro do campo da terapia ocupacional social pode contribuir para a construção de ferramentas de leitura e análise socioculturais, assim como para o desenvolvimento de procedimento metodológico no âmbito da ação da terapia ocupacional social, ou seja, intervenção social em que universo cultural e a participação dos usuários sejam eixos-guiasna formulação de projetos pessoais e coletivos. / Homeless population, as social group, transits between vulnerability and disaffiliation zones (as defined by Robert Castel), for it is frequently submitted to unemployment or temporary jobs and a trajectory marked by ruptures. In many cases, the assistance net is the fundamental element in its daily organization. That social group heterogeneity constitutes a premise of this study. Inside such diversity, groups and people were identified as a possibility of reference for the discussion of endogenous/interior (and auto-organizing) ways of overcoming that condition. Therefore, this study focus on comprehending the process opposed to the movement of social dissociation, besides covering the development of such strategies as the creation of social nets and the identity strengthening. This ethnographic research involved extended close acquainting with the study group and their ways of life. Data collection took 12 months in 2006, with field observation, interviews and document collecting. Five collaborators were interviewed, and their city circuits and points were visited. Criteria for including collaborators included to be engaged in a lodging program, to participate in a political organization (specific social movements), to integrate relationship nets of religious character, to integrate circuits linked to art and culture, to use services of the assistance net as complementary resource for the daily organization, and to have ways of income generating. Besides these dimensions, that suggest different social participation forms, another criterion for selecting collaborators was to be or to have been homeless for more than two years. Analysis was conducted under two perspectives. First, with reference to each collaborator life story reconstitution, with the main objective of showing their interdependence nets, which transcend assistance circuits, and discussing its singularity in the constructing process of identities able to re-signify and give historicity to the homeless condition. The other analysis perspective was to start from the perception of common axes and themes the contribute to the rethinking possible connections, assistance propositions and other proximity nets, dealt in items referring social assistance, political participation and education. It was observed the construction of disaffiliation-opposed movements, a process that signify the construction of diversified identities that make relative and contextualize the place attributed to homeless people, normally associated to unsuccessfulness and dependence on official services. Notwithstanding, it is urgent to produce preventive situations and collective wayouts. The study of social nets in occupational therapy field may contribute to the construction of socio-cultural reading and analyzing tools, as well as to the development of methodological procedure in social occupational therapy, that is, social intervention in which cultural universe and user\'s participation are guidelines for personal and collective projects formulation
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Pessoas em situação de rua na cidade de São Paulo: itinerários e estratégias na construção de redes sociais e identidades / Homeless people in the city of São Paulo: routes and strategies in the construction of social nets and identitiesDebora Galvani 01 October 2008 (has links)
Compreende-se que a população em situação de rua, enquanto grupo social, transita entre zonas de vulnerabilidade e desfiliação conforme definidas por Robert Castel, pois está freqüentemente submetida à ausência de emprego ou a trabalhos temporários e a uma trajetória marcada por rupturas. Em muitos casos, a rede de assistência é o elemento fundamental na sua organização cotidiana. A heterogeneidade deste grupo social constitui uma premissa neste estudo. No interior de tal diversidade, foram identificados grupos e pessoas que pareciam proporcionar referência para a discussão de formas endógenas/internas (e de auto-organização) de superação dessa condição. Assim, meu interesse neste estudo esteve voltado para a compreensão dos processos contrários ao movimento de dissociação social, além de abranger o desenvolvimento de estratégias como a criação de redes sociais e o fortalecimento de identidades. Trata-se de pesquisa etnográfica, envolvendo convívio prolongado com o grupo social estudado e aproximação com seus modos de vida. A coleta de dados foi realizada por doze meses em 2006, com observação de campo, entrevistas e coleta de documentos. Foram realizadas entrevistas com cinco colaboradores e visitas aos seus circuitos e \"pedaços\" pela cidade. Os critérios para inclusão dos colaboradores da pesquisa foram: estar inserido em programa de moradia; participar de organização política (movimentos sociais específicos); integrar redes de relações de caráter religioso; integrar circuitos ligados a arte e cultura; utilizar serviços da rede assistencial como recurso complementar para organização de seu cotidiano; possuir formas de geração de renda. Além destas dimensões, que sugerem diferentes formas de participação social, foi critério de seleção o colaborador estar ou ter vivido em situação de rua por mais de dois anos. A análise foi realizada em duas perspectivas. Uma refere-se à reconstituição da história de vida de cada colaborador, com o objetivo central de mostrar suas redes de interdependência, as quais transcendem os circuitos assistenciais, e de discutir sua singularidade no processo de construção de identidades capazes de ressignificar e dar historicidade à experiência da situação de rua. Outra perspectiva de análise foi partir da percepção de eixos e temáticas comuns que contribuem para repensar possíveis conexões, propostas assistenciais e outras redes de proximidade, as quais foram trabalhadas nos itens relativos a recurso à assistência social, participação política e educação. Observou-se a construção de movimentos opostos à desfiliação cujos processos significam a construção de identidades diferenciadas que tornam relativo e contextualizado o lugar atribuído à pessoa em situação de rua, geralmente associado a fracassos e à dependência dos serviços. Há, porém, necessidade de se produzir situações preventivas e alternativas coletivas. O estudo das redes sociais dentro do campo da terapia ocupacional social pode contribuir para a construção de ferramentas de leitura e análise socioculturais, assim como para o desenvolvimento de procedimento metodológico no âmbito da ação da terapia ocupacional social, ou seja, intervenção social em que universo cultural e a participação dos usuários sejam eixos-guiasna formulação de projetos pessoais e coletivos. / Homeless population, as social group, transits between vulnerability and disaffiliation zones (as defined by Robert Castel), for it is frequently submitted to unemployment or temporary jobs and a trajectory marked by ruptures. In many cases, the assistance net is the fundamental element in its daily organization. That social group heterogeneity constitutes a premise of this study. Inside such diversity, groups and people were identified as a possibility of reference for the discussion of endogenous/interior (and auto-organizing) ways of overcoming that condition. Therefore, this study focus on comprehending the process opposed to the movement of social dissociation, besides covering the development of such strategies as the creation of social nets and the identity strengthening. This ethnographic research involved extended close acquainting with the study group and their ways of life. Data collection took 12 months in 2006, with field observation, interviews and document collecting. Five collaborators were interviewed, and their city circuits and points were visited. Criteria for including collaborators included to be engaged in a lodging program, to participate in a political organization (specific social movements), to integrate relationship nets of religious character, to integrate circuits linked to art and culture, to use services of the assistance net as complementary resource for the daily organization, and to have ways of income generating. Besides these dimensions, that suggest different social participation forms, another criterion for selecting collaborators was to be or to have been homeless for more than two years. Analysis was conducted under two perspectives. First, with reference to each collaborator life story reconstitution, with the main objective of showing their interdependence nets, which transcend assistance circuits, and discussing its singularity in the constructing process of identities able to re-signify and give historicity to the homeless condition. The other analysis perspective was to start from the perception of common axes and themes the contribute to the rethinking possible connections, assistance propositions and other proximity nets, dealt in items referring social assistance, political participation and education. It was observed the construction of disaffiliation-opposed movements, a process that signify the construction of diversified identities that make relative and contextualize the place attributed to homeless people, normally associated to unsuccessfulness and dependence on official services. Notwithstanding, it is urgent to produce preventive situations and collective wayouts. The study of social nets in occupational therapy field may contribute to the construction of socio-cultural reading and analyzing tools, as well as to the development of methodological procedure in social occupational therapy, that is, social intervention in which cultural universe and user\'s participation are guidelines for personal and collective projects formulation
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COLABORAÇÃO, (CIBER)ATIVISMO E SUBJETIVIDADE / COLLABORATION, (CYBER) ACTIVISM AND SUBJECTIVITYMartins, Fernanda Goulart 05 April 2013 (has links)
This Master Dissertation provides a discussion about subjectivity production, collaborative
inventions and cyber activism in neoliberal capitalist and network society. It aims to analyze
how subjectivities are built on and configured in the production of discourses on collaborative
social spaces in the network society. For this purpose, the research is organized in the form of
three articles, intending to (a) construct a methodological pathway that enables an approach to
collaborative production, (b) reflect on what collaborative inventions propose in their
productions and how they arrange collectively the collaborative inventions and (c) provide a
reflection on the knowledge that compose and produce cyber activism. This qualitative
research has its reflections based on Critical Social Psychology, but dialogs with other
theoretical approaches, such as the phenomenological tradition and hermeneutics, whose
epistemological assumptions underpin the reflections developed in the first article, and the
philosophy of difference, which provides important concepts for the development of the two
following articles. Participant observation and focus groups were proposed as method. This
discussions and reflections lead to consider that collaborative productions work and in
network and provide resistance and invention processes in search of social transformation. / A presente dissertação pretende colocar em discussão a produção de subjetividades, as
invenções colaborativas e o (ciber)ativismo na sociedade neoliberal capitalista e configurada
em rede. O objetivo é analisar como as subjetividades se configuram na produção de
discursos em espaços colaborativos na sociedade em rede. Para isso, a pesquisa é organizada
em forma de três artigos, pretendendo (a) construir um trajeto metodológico que permita uma
aproximação das produções colaborativas e a identificação de alguns sentidos que orbitam no
ciberespaço, dentro e em torno dessas produções, (b) refletir sobre o que os coletivos que
produzem invenções colaborativas propõem e como se agenciam coletivamente e (c) refletir
sobre os saberes que constituem e produzem o devir-(ciber)ativista nas produções
colaborativas. Trata-se de um estudo com abordagem qualitativa, que se baseia
principalmente em pressupostos da Psicologia Social Crítica, mas em diálogo com outras
abordagens, como a tradição fenomenológica e a hermenêutica, cujos pressupostos
epistemológicos sustentam as reflexões propostas no primeiro artigo, e a filosofia da
diferença, que fornece importantes conceitos para o desenvolvimento dos dois artigos
seguintes. Foram propostos como método a observação participante e grupos focais. As
reflexões sobre os discursos nos levam a considerar que as produções colaborativas se
articulam em rede e propiciam processos de resistência e invenção em busca da transformação
social.
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EXAMINING PALLIATIVE CARE NETWORKS IN ENHANCING COMMUNITY PALLIATIVE CAREBainbridge, Daryl 10 1900 (has links)
<p><strong>Introduction</strong></p> <p>Despite increasing global interest in regional palliative care networks (PCN) to integrate care, little explicit direction exists to guide their evaluation. The first step of this research was to develop a comprehensive conceptual framework using a systems approach for evaluating integrated palliative care. This framework was then used to guide a rigorous examination of a selected PCN.</p> <p><strong>Methods</strong></p> <p>The conceptual framework was derived from the empirical literature, incorporating principal features of network integration. A case study methodology was used to assess structure (administration) and process (provider) levels in the framework through document review, a PCN executive interview, and surveys with organizational administrators and health professionals who provide palliative care in the community catchment of the PCN.</p> <p><strong>Results</strong></p> <p>Key features to efficient palliative care delivery are currently lacking across this PCN area. Still, the 20 responding administrators (90% response rate) largely viewed Network accomplishments positively and the resulting partnerships as beneficial and collaborative. Additional efforts were seen as required in ensuring palliative care patient identification, reducing silos between organizations, and greater by-in from regional authorities. Relative to processes, the 86 health care providers (85% response rate) reported valuing collaboration and reflected positively on many of the framework elements measured. Insufficiencies were perceived in support for case conferencing and evaluative activities, as well as in informational access.</p> <p><strong> </strong></p> <p><strong>Conclusion</strong></p> <p>This study enabled us to test both the utility of the framework and the capacity of the selected PCN for providing quality, integrated palliative care. This study represents an important initial attempt at examining network-integrated palliative care.</p> / Doctor of Philosophy (PhD)
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Toward a Grounded Theory of Community NetworkingMasten-Cain, Kathryn 05 1900 (has links)
This dissertation presents a preliminary grounded theory of community networking based on 63 evaluations of community networking projects funded by the National Telecommunications and Information Administration’s Technology Opportunities Program (TOP) between 1994 and 2007. The substantive grounded theory developed is that TOP projects differed in their contribution to positive outcomes for intended disadvantaged community beneficiaries based on the extent and manner in which they involved the disadvantaged community during four grant process phases: partnership building, project execution, evaluation, and close-out. Positive outcomes for the community were facilitated by using existing communication channels, such as schools, to connect with intended beneficiaries; local financial institutions to provide infrastructure to support local trade; and training to connect community members to jobs. Theoretical contributions include situating outcomes for disadvantaged communities within the context of the grant process; introducing the “vulnerable community” concept; and identifying other concepts and properties that may be useful in further theoretical explorations. Methodological contributions include demonstrating grounded theory as a viable method for exploring large text-based datasets; paving the way for machine learning approaches to analyzing qualitative data; and illustrating how project evaluations can be used in a similar fashion as interview data. Practical contributions include providing information to guide community networking-related policies and initiatives from the perspectives of stakeholders at all levels, including establishing funded projects as local employment opportunities and re-conceptualizing sustainability in terms of human networks rather than technological networks.
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Jovens entre culturas: itinerários e perspectivas de jovens Guarani entre a aldeia Boa Vista e a cidade de Ubatuba / Youths within cultures: itineraries and perspectives of the young Guarani among the village Boa Vista and the city of UbatubaMacedo, Maria Daniela Corrêa de 29 March 2010 (has links)
O estudo propôs conhecer as relações dos jovens Guarani com a comunidade da aldeia Boa Vista e a cidade de Ubatuba. O trabalho de campo e análises foram realizadas com 12 jovens entre 13 e 29 anos que participaram como colaboradores. As principais temáticas foram no campo da educação e saúde; além dos estudos das histórias de vida compostas nos eixos entre cidade/ aldeia relativos aos itinerários dos jovens, suas redes sociais e perspectivas futuras. Na saúde verificamos as tensões existentes nas relações de poder entre o conhecimento técnico-científico e os procedimentos Guarani de saúde. E na educação, o aprendizado e domínio do português aparecem como essenciais nas relações sociais interculturais, isto é, para o diálogo e negociações com outras culturas / This study intended to deepen the knowledge of the relationship of Guarani youths with the community of Boa Vista village and the city of Ubatuba (SP). Field work and analysis were performed with twelve 13- and 29-year old youngsters, in which they took part as collaborators. The main themes focus in the field of Education, Health and also studies of Composed Life History within the axis of the city-village related to the youths\' itineraries, their social nets and of their future perspectives. In the Health issue, we witnessed the existence of tensions between the power of the technical-scientific knowledge and the procedures undertaken within the Guaranis own Health approach. In the Education issue, the fact of having fluency, learning and dominating the Portuguese language seems as an essential part of their social relationship with Brazilian society, because of the need to negotiate and dialog with other cultures
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Coping with rural risk : assets, labour allocation, migration, and community networksMalaeb, Bilal January 2016 (has links)
Given the importance of agricultural income for rural households, erratic weather conditions pose an austere threat to these households' livelihoods. This thesis explores ways through which households in agrarian economies smooth their consumption, engage in community networks, and readjust their labour allocation in response to shocks. In a setting of inherent risk, absence of institutional insurance, and labour market inefficiencies, poor households are often left to their own devices to cope with risk. The aim of this study is to examine the different risk-coping strategies adopted by households in rural India, assess their effectiveness, and derive implications for public policy. The results suggest that, in an environment characterised by agro-climatic risk, households are able to self-insure and smooth their consumption in the face of income shocks. Their coping mechanisms, however, may reduce their resilience to future shocks. In fact, small landholders tend to rely more heavily on their productive asset stock, while medium landholders find it optimal to preserve and accumulate their productive assets when exposed to exogenous income shocks. Households also change their labour allocation and reduce their self-employment in agriculture. Furthermore, households in rural areas can migrate to urban areas or engage in societal risk-sharing arrangements to mitigate the risk. The results of this thesis suggest that being part of a community network discourages individuals' migration and increases the likelihood of undertaking riskier activities. The findings also confirm the importance of portfolio adjustments and the diversification of household assets in buffering consumption. These conclusions form the basis of several policy implications, the most important of which is providing formal insurance schemes to encourage the accumulation of assets, technology, and skills.
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Jovens entre culturas: itinerários e perspectivas de jovens Guarani entre a aldeia Boa Vista e a cidade de Ubatuba / Youths within cultures: itineraries and perspectives of the young Guarani among the village Boa Vista and the city of UbatubaMaria Daniela Corrêa de Macedo 29 March 2010 (has links)
O estudo propôs conhecer as relações dos jovens Guarani com a comunidade da aldeia Boa Vista e a cidade de Ubatuba. O trabalho de campo e análises foram realizadas com 12 jovens entre 13 e 29 anos que participaram como colaboradores. As principais temáticas foram no campo da educação e saúde; além dos estudos das histórias de vida compostas nos eixos entre cidade/ aldeia relativos aos itinerários dos jovens, suas redes sociais e perspectivas futuras. Na saúde verificamos as tensões existentes nas relações de poder entre o conhecimento técnico-científico e os procedimentos Guarani de saúde. E na educação, o aprendizado e domínio do português aparecem como essenciais nas relações sociais interculturais, isto é, para o diálogo e negociações com outras culturas / This study intended to deepen the knowledge of the relationship of Guarani youths with the community of Boa Vista village and the city of Ubatuba (SP). Field work and analysis were performed with twelve 13- and 29-year old youngsters, in which they took part as collaborators. The main themes focus in the field of Education, Health and also studies of Composed Life History within the axis of the city-village related to the youths\' itineraries, their social nets and of their future perspectives. In the Health issue, we witnessed the existence of tensions between the power of the technical-scientific knowledge and the procedures undertaken within the Guaranis own Health approach. In the Education issue, the fact of having fluency, learning and dominating the Portuguese language seems as an essential part of their social relationship with Brazilian society, because of the need to negotiate and dialog with other cultures
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INSPIRE (INvestigating Social and PractIcal suppoRts at the End of life): Pilot randomised trial of a community social and practical support intervention for adults with life-limiting illnessMcLoughlin, K., Rhatigan, J., McGilloway, S., Kellehear, Allan, Lucey, M., Twomey, F., Conroy, M., Herrera-Molina, E., Kumar, S., Furlong, M., Callinan, J., Watson, M., Currow, D., Bailey, C. January 2015 (has links)
Yes / Yes / For most people, home is the preferred place of care and death. Despite the development of specialist palliative care and primary care models of community based service delivery, people who are dying, and their families/carers, can experience isolation, feel excluded from social circles and distanced from their communities. Loneliness and social isolation can have a detrimental impact on both health and quality of life. Internationally, models of social and practical support at the end of life are gaining momentum as a result of the Compassionate Communities movement. These models have not yet been subjected to rigorous evaluation. The aims of the study described in this protocol are: (1) to evaluate the feasibility, acceptability and potential effectiveness of The Good Neighbour Partnership (GNP), a new volunteer-led model of social and practical care/support for community dwelling adults in Ireland who are living with advanced life-limiting illness; and (2) to pilot the method for a Phase III Randomised Controlled Trial (RCT). DESIGN: The INSPIRE study will be conducted within the Medical Research Council (MRC) Framework for the Evaluation of Complex Interventions (Phases 0-2) and includes an exploratory two-arm delayed intervention randomised controlled trial. Eighty patients and/or their carers will be randomly allocated to one of two groups: (I) Intervention: GNP in addition to standard care or (II) Control: Standard Care. Recipients of the GNP will be asked for their views on participating in both the study and the intervention. Quantitative and qualitative data will be gathered from both groups over eight weeks through face-to-face interviews which will be conducted before, during and after the intervention. The primary outcome is the effect of the intervention on social and practical need. Secondary outcomes are quality of life, loneliness, social support, social capital, unscheduled health service utilisation, caregiver burden, adverse impacts, and satisfaction with intervention. Volunteers engaged in the GNP will also be assessed in terms of their death anxiety, death self efficacy, self-reported knowledge and confidence with eleven skills considered necessary to be effective GNP volunteers. DISCUSSION: The INSPIRE study addresses an important knowledge gap, providing evidence on the efficacy, utility and acceptability of a unique model of social and practical support for people living at home, with advanced life-limiting illness. The findings will be important in informing the development (and evaluation) of similar service models and policy elsewhere both nationally and internationally. TRIAL REGISTRATION: ISRCTN18400594 18(th) February 2015.
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Managing Mobility for Distributed Smart Cities ServicesLUZURIAGA QUICHIMBO, JORGE ELOY 07 July 2017 (has links)
The IoT refers to the idea of internetworking physical devices, vehicles, buildings, and any other item embedded with the appropriate electronics, software, sensors, actuators, and network connectivity to allows them to interchange data and to provide highly effective new services. In this thesis we focus on the communications issues of the IoT in relation to mobility and we provide different solutions to alleviate the impact of these potential problems and to guarantee the information delivery in mobile scenarios.
Our reference context is a Smart City where various mobile devices collaboratively participate, periodically sending information from their sensors. We assume that these services are located in platforms based in cloud infrastructures where the information is protected through the use of virtualisation ensuring their security and privacy.
This thesis is structured into seven chapters. We first detail our objectives and identify the current problems we intend to address. Next, we provide a thorough review of the state of the art of all the areas involved in our work, highlighting how we improved the existing solutions with our research. The overall approach of the solutions we propose in this thesis use prototypes that encompasses and integrates different technologies and standards in a small infrastructure, using real devices in real scenarios with two of the most commonly used networks around the world: WiFi and 802.15.4 to efficiently solve the problems we originally identified.
We focussed on protocols based on a producer/consumer paradigm, namely AMQP and particularly MQTT. We observed the behaviour of these protocols using in lab experiments and in external environments, using a mesh wireless network as the backbone network. Various issues raised by mobility were taken into consideration, and thus, we repeated the tests with different messages sizes and different inter-message periodicity, in order to model different possible applications. We also present a model for dimensioning the number of sources for mobile nodes and calculating the number of buffers required in the mobile node as a function of the number of sources and the size of the messages.
We included a mechanism for avoiding data loss based on intermediate buffering adapted to the MQTT protocol that, in conjunction with the use of an alternative to the Network Manager in certain contexts, improves the connection establishment for wireless mobile clients. We also performed a detailed study of the jitter behaviour of a mobile node when transmitting messages with this proposal while moving through a real outdoor scenario. To emulate simple IoT networks we used the Cooja simulator to study and determine the effects on the probability of delivering messages when both publishers and subscribers were added to different scenarios. Finally we present an approach that combines the MQTT protocol with DTN which we specifically designed for constrained environments and guarantees that important information will never be lost.
The advantage of our proposed solutions is that they make an IoT system more resilient to changes in the point of attachment of the mobile devices in an IoT network without requiring IoT application & service developers to explicitly consider this issue. Moreover, our solutions do not require additional support from the network through protocols such as MobileIP or LISP. We close the thesis by providing some conclusions, and identifying future lines of work which we unable to address here. / Internet de las cosas (IoT) se refiere a la idea de interconectar sensores, actuadores, dispositivos físicos, vehículos, edificios y cualquier elemento dotado de la electrónica, así como del software y de la conectividad de red que los hace capaces de intercambiar datos para proporcionar servicios altamente efectivos.
En esta tesis nos centramos en temas relacionados con la comunicación de sistemas IoT, específicamente en situaciones de movilidad y en los problemas que esto conlleva. Con este fin ofrecemos diferentes soluciones que alivian su impacto y garantizan la entrega de información en estas situaciones.
El contexto de referencia es una ciudad inteligente donde varios dispositivos móviles participan de forma colaborativa enviando periódicamente información desde sus sensores hacia servicios ubicados en plataformas en la nube (cloud computing) donde mediante el uso de virtualización, la información está protegida garantizando su seguridad y privacidad.
Las soluciones propuestas en esta tesis se enfocan en probar sobre una pequeña infraestructura un prototipo que abarca e integra diferentes tecnologías y estándares para resolver eficientemente los problemas previamente identificados. Hemos enfocado nuestro esfuerzo en el uso de dispositivos sobre escenarios reales con dos de las redes más extendidas en todo el mundo: WiFi y enlaces 802.15.4.
Nos enfocamos en protocolos que ofrecen el paradigma productor/consumidor como el protocolo avanzado de colas de mensajes (AMQP) y particularmente el protocolo de transporte de mensajes telemétricos (MQTT), observamos su comportamiento a través de experimentos en laboratorio y en pruebas al aire libre, repitiendo las pruebas con diferentes tamaños de mensajes y diferente periodicidad entre mensajes. Para modelar las diferentes posibles aplicaciones de la propuesta, se tomaron en consideración varias cuestiones planteadas por la movilidad, resultando en un modelo para dimensionar eficientemente el número de fuentes para un nodo móvil y para calcular el tamaño requerido del buffer, en función del número de fuentes y del tamaño de los mensajes.
Proponemos un mecanismo adaptado al protocolo MQTT que evita la pérdida de datos en clientes móviles, basado en un buffer intermedio entre la producción y publicación de mensajes que, en conjunto con el uso de una alternativa al gestor de conexiones inalámbricas "Network Manager", en ciertos contextos mejora el establecimiento de las conexiones. Para la evaluación de esta propuesta se presenta un estudio detallado de un nodo móvil que se mueve en un escenario real al aire libre, donde estudiamos el comportamiento del jitter y la transmisión de mensajes.
Además, hemos utilizado emuladores de redes IoT para estudiar y determinar los efectos sobre la probabilidad de entrega de mensajes, cuando se agregan tanto publicadores como suscriptores a diferentes escenarios. Finalmente, se presenta una solución totalmente orientada a entornos con dispositivos de recursos limitados que combina los protocolos MQTT con redes tolerantes a retardos (DTN) para garantizar la entrega de información.
La ventaja de las soluciones que proponemos reside en el hecho de que los sistemas IoT se vuelven resilientes a la movilidad y a los cambios de punto de acceso, permitiendo así que los desarrolladores creen fácilmente aplicaciones y servicios IoT evitando considerar estos problema. Otra ventaja de nuestras soluciones es que no necesitan soporte adicional de la red como sucede con protocolos como MobileIP o el protocolo que separa el identificador del localizador (LISP). Se destaca cómo hemos mejorado las soluciones existentes hasta el momento de la escritura de esta disertación, y se identifican futuras líneas de actuación que no han sido contempladas. / Internet de les coses (IoT) es refereix a la idea d'interconnectar sensors, actuadors, dispositius físics, vehicles, edificis i qualsevol element dotat de l'electrònica, així com del programari i de la connectivitat de xarxa que els fa capaces d'intercanviar dades per proporcionar serveis altament efectius.
En aquesta tesi ens centrem en temes relacionats amb la comunicació de sistemes IoT, específicament en situacions de mobilitat i en els problemes que això comporta. A aquest efecte oferim diferents solucions que alleugeren el seu impacte i garanteixen el lliurament d'informació en aquestes situacions.
El context de referència és una ciutat intel·ligent on diversos dispositius mòbils participen de forma col·laborativa enviant periòdicament informació des dels seus sensors cap a serveis situats en plataformes en el núvol (cloud computing) on mitjançant l'ús de virtualització, la informació està protegida garantint la seva seguretat i privadesa.
Les solucions proposades en aquesta tesi s'enfoquen a provar sobre una xicoteta infraestructura un prototip que abasta i integra diferents tecnologies i estàndards per a resoldre eficientment els problemes prèviament identificats. Hem enfocat el nostre esforç en l'ús de dispositius sobre escenaris reals amb dos de les xarxes més esteses a tot el món: WiFi i enllaços 802.15.4.
Ens enfoquem en protocols que ofereixen el paradigma productor/consumidor com el protocol avançat de cues de missatges (AMQP) i particularment el protocol de transport de missatges telemètrics (MQTT), observem el seu comportament a través d'experiments en laboratori i en proves a l'aire lliure, repetint les proves amb diferents grandàries de missatges i diferent periodicitat entre missatges. Per a modelar les diferents possibles aplicacions de la proposta, es van prendre en consideració diverses qüestions plantejades per la mobilitat, resultant en un model per a dimensionar eficientment el nombre de fonts per a un node mòbil i per a calcular la grandària requerida del buffer, en funció del nombre de fonts i de la grandària dels missatges.
Proposem un mecanisme adaptat al protocol MQTT que evita la pèrdua de dades per a clients mòbils, basat en un buffer intermedi entre la producció i publicació de missatges que en conjunt amb l'ús d'una alternativa al gestor de connexions sense fils "Network Manager'', en certs contextos millora l'establiment de les connexions. Per a l'avaluació d'aquesta proposta es presenta un estudi detallat d'un node mòbil que es mou en un escenari real a l'aire lliure, on estudiem el comportament del jitter i la transmissió de missatges.
A més, hem utilitzat emuladors de xarxes IoT per a estudiar i determinar els efectes sobre la probabilitat de lliurament de missatges, quan s'agreguen tant publicadors com subscriptors a diferents escenaris. Finalment, es presenta una solució totalment orientada a entorns amb dispositius de recursos limitats que combina els protocols MQTT amb xarxes tolerants a retards (DTN) per a garantir el lliurament d'informació.
L'avantatge de les solucions que proposem resideix en el fet que els sistemes IoT es tornen resilients a la mobilitat i als canvis de punt d'accés, permetent així que els desenvolupadors creuen fàcilment aplicacions i serveis IoT evitant considerar aquests problema. Un altre avantatge de les nostres solucions és que no necessiten suport addicional de la xarxa com succeeix amb protocols com MobileIP o el protocol que separa l'identificador del localitzador (LISP). Es destaca com hem millorat les solucions existents fins al moment de l'escriptura d'aquesta dissertació, i s'identifican futures línies d'actuació que no han sigut contemplades. / Luzuriaga Quichimbo, JE. (2017). Managing Mobility for Distributed Smart Cities Services [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84744 / TESIS
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