Tras el éxito del Proyecto de los Juegos Panamericanos en el Perú, se dio a conocer ante la sociedad los mecanismos adoptados, por la organización, para lograr los objetivos propuestos en el proyecto. Los Contratos NEC utilizados para el proyecto de los Juegos Panamericanos es un aporte innovador para el sector construcción en nuestro país, se basa principalmente en metodologías colaborativas que enfocan todas sus directrices en el éxito del proyecto y el bienestar de todos los involucrados. El presente proyecto de tesis busca la adaptación de las formas, mecanismos y metodologías de la Gestión Colaborativa NEC en proyectos tradicionales de construcción que se realizan en el Perú, enfocándose principalmente en viviendas multifamiliares en la ciudad de Lima. La investigación plantea resolver la problemática de falta de comunicación e integración de los Stakeholders en proyectos Multifamiliares en Lima. Por ello, a partir de una encuesta de Juicio de expertos que están involucrados en gestión colaborativa de proyectos de construcción se pudo validar la problemática y obtener información valiosa para la investigación. Asimismo, se analizó el proyecto del Complejo Andrés Avelino Cáceres que se realizó dentro del proyecto especial Juegos Panamericanos bajo la metodología NEC, y en base a ello se obtuvo un análisis de riesgos, aplicación de la Junta de Solución de Disputas (DAB) y la gestión de involucrados. Todo ello, se realizó con la finalidad de obtener datos más precisos sobre la gestión colaborativa NEC. Además, en base a los procedimientos anteriores se plantea una propuesta para la gestión de Stakeholders, riesgos y el uso del DAB. Enfocándose principalmente en la integración y comunicación de los Stakeholders en las etapas de Inicio, Planificación, Ejecución y Control del Proyecto. Finalmente se proponen flujogramas para el correcto desarrollo de la gestión de Stakeholders para las diferentes etapas del ciclo de vida del proyecto y herramientas para adoptar esta metodología como: sesiones ICE, un formato para las visitas a obra por parte del DAB, control y mejora continua de la gestión colaborativa. / After the success of the Pan American Games Project in Peru, the mechanisms adopted by the organization to achieve the objectives proposed in the project were made known to society. The NEC Contracts used for the Pan American Games project is an innovative contribution to the construction sector in our country, it is based on collaborative methodologies that focus all its guidelines on the success of the project and the well-being of all involved. This thesis project seeks the adaptation of the forms, mechanisms and methodologies of NEC Collaborative Management in common projects carried out in Peru, focusing mainly on multi-family projects in the city of Lima. The research aims to solve the problem of lack of communication and integration of Stakeholders in Multifamily projects in Lima. For this reason, a survey of experts who are involved in collaborative management of construction projects was able to validate the problem and obtain valuable information for the investigation. Likewise, the project of the Andrés Avelino Cáceres Complex that was carried out within the Pan American Games project under the NEC methodology was analyzed, and based on this, a risk analysis was obtained, using the Dispute Resolution Board (DAB) and the management of involved. All this was done in order to obtain more precise data on NEC collaborative management. Based on the above procedures, a proposal is made for the management of Stakeholders, risks and the use of DAB. Focusing mainly on the integration and communication of those Involved in the Start, Planning, Execution and Control stages of the Project. Flowcharts of stakeholder management development are proposed for these stages and tools to adopt this methodology such as: ICE sessions, a format for site visits by DAB, control and improvement of collaborative management. / Tesis

The permitting process to determine whether high volume hydraulic fracturing (HVHF) should be allowed in New York State has been controversial and protracted. There have been intense disputes between those who see HVHF as an economic benefit and those who assert it will jeopardize health and the environment. Using the case study research method, perceptions of directly affected stakeholders regarding the issues, benefits and limitations associated with the public participation process were explored. Purposive sampling yielded participants from the natural gas industry, municipal governments, local landowners and residents. Data collection methods involved in-depth interviews, focus groups and document analysis. Since the HVHF conflict concerned a future possibility of environmental degradation, theoretical foundations included complex systems and green ideology, the enactment of power and social dominance, environmental conflict resolution, and principles of collaborative management. Findings demonstrate that the public participation process was embedded in a traditional top-down policy development approach that did not accommodate conditions of high uncertainty, nor did it allow for the broader and deeper discourse needed when development involves socio-economic and environmental justice issues. Implications include the potential to apply principles and methods of collaborative management typically used for natural resource management. In particular, the adaptive co-management approach provides a framework for managing issues that require problem solving over time, an essential missing element of the current HVHF stakeholder engagement process where diverse stakeholders identified issues of trust, empowerment, rights and fairness.

Thesis (PhD (Dept. of Forest and Wood Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This study aimed to analyze under which conditions the structure, organization and integration of knowledge systems can provide the implementation of adaptive collaborative management of natural resources under conditions of high biodiversity in the humid forest zone of southern Cameroon. The study specifically did the following: characterized sustainable slash-and-burn agriculture innovations; examined the influences of local perceptions of nature and forest knowledge management systems on adaptive slash-and-burn agriculture practices; analyzed the influences of the social representation of land use patterns and their local indicators on agro-ecological sustainability; characterised the biophysical dimensions of local management of agricultural biodiversity knowledge systems; analyzed how local agricultural biodiversity knowledge is used to adapt and to satisfy household consumption needs, market preferences, and sustainable livelihoods; examined the influences of local perceptions of climate variability for the ability and adaptive capacity of people to use local knowledge to deal with the effect of pests-diseases on crop yield, corrective management actions, and adaptive slash-and-burn agriculture management. The study was conducted in three blocks within the humid forest zone of southern Cameroon along a gradient of natural resource use management intensification and population density. Data were collected via structured and semi-structured interviews, multi-disciplinary landscape assessment and a review of secondary information. Chisquare tests were used to show how local knowledge influences - natural resource management at the forest-agriculture interface, while binary logistic regressions were used to understand the influences of biophysical and socio-economic factors on farmers’ decisions to domesticate tree species and to cultivate several crop cultivars. Fourteen research and development (R&D) themes were identified and found to be equally distributed among blocks but unequally distributed across technical, marketing and socio-organisational types of innovation. There was a gap between social demand and innovation offer. Innovations offered covered more technical issues, such as crop variety development, indicating their agricultural focus rather than the integration of forest and agriculture issues. The local perceptions of nature and forest resources are based on social representation of the vital space into components having a specific function for the social, physical and spiritual life of people. Needs of the human world determine the role of local forest knowledge systems in the interpretation and responses of the natural environment, and guide the trajectories of natural resource management practices. The management of agro-ecological sustainability is based on the local definition of well-being, social representation of space and on a multi-criteria approach combining bio-indicators such as plants, earthworm activities, age of vegetation or forest cover, soil colour and quality but it is also positively influenced by land use history, the use value of wild plant and crop species, the knowledge of crop qualities, the knowledge of interactions between crops, and between crops and other wild plant species, the tree size of tree species used, the future use of a current land use, the estimated land use for own use and market access. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om te bepaal onder watter omstandighede die struktuur, organisasie en integrasie van kennissisteme kan bydra tot die implementering van aanpasbare deelnemende bestuur van natuurlike hulpbronne onder toestande van hoë biodiversiteit in die vogtige woudsone van suidelike Kameroen. Die studie het spesifiek die volgende gedoen: volhoubare kap-en-brand landboukundige ontwikkelinge gekarakteriseer; die invloede van plaaslike persepsies van die natuur en woudkennisgebaseerde bestuursisteme op aanpasbare kap-en-brand landboupraktyke ge-evalueer; die invloede van die sosiale verteenwoordiging van grondgebruikspatrone en hul plaaslike indikatore op agro-ekologiese volhoubaarheid ontleed; die biofisiese dimensies van die plaaslike bestuur van landboukundige biodiversiteitskennissisteme gekarakteriseer; geanaliseer hoe die plaaslike landboukundige biodiversiteitskennis gebruik word om aan te pas by en bevrediging te verkry vir huishoudelike gebruiksbehoeftes, marksvoorkeure en volhoubare bestaansbehoeftes; die invloede en gebruik van plaaslike kennis en persepsies van klimaatsvariasie beoordeel in die vermoë en aanpassingskapasiteit van mense om die effekte van siektes-peste op gewasproduksie, regstellende aksies en aanpasbare kap-enbrand landboubestuur te hanteer. Die studie is uitgevoer in drie blokke binne die vogtige woudsone van suidelike Kameroen langs ‘n gradient van natuurlike hulpbrongebruiksbestuursintensiteit en populasiedigtheid. Data is versamel deur gestruktureerde en semi-gestruktureerde onderhoude, multi-dissiplinere landskapsevaluering en ‘n oorsig van sekondere inligting. Chi-kwadraat toetse is gebruik om te wys hoe plaaslike kennis die bestuur van die woudlandbou konneksie beinvloed asook binêre logistiese regressies om die invloede te verstaan van biofisiese en sosio-ekonomiese faktore op die boere se besluite om boomsoorte te domestikeer en om verskeie gewaskultivars te kweek. Veertien temas in navorsing en ontwikkeling (N&O) was gelyk versprei tussen die blokke en ongelyk versprei tussen tegniese, bemarking en sosio-organisatoriese tipes innovering. Daar was ‘n gaping tussen sosiale aanvraag en innoveringsaanbieding. Innoverings het meer tegniese aspekte gedek, soos ontwikkeling van ‘n verskeidenheid gewasse, wat wys op ‘n landboukundige fokus eerder as ‘n integrasie van woud en landboukundige aspekte. Die plaaslike persepsies van die natuur en woudhulpbronne was gebaseer op sosiale verteenwoordiging van lewensbelangrike ruimte in komponente met ‘n spesifieke funksie vir die sosiale, fisiese en geestelike lewe van die mense. Behoeftes van die menslike wereld bepaal die rol van plaaslike woudkennissisteme in die interpretasie van en reaksie op die natuurlike omgewing, en rig die gebruik van hulpbronbestuurspraktyke. Die bestuur van agro-ekologiese volhoubaarheid is gebaseer op die plaaslike definisie van geluk, sosiale verteenwoordiging van ruimte en op ‘n multikriteria benadering wat bio-indikatore kombineer soos plante, erdwurmaktiwiteite, ouderdom van plantegroei- of woudbedekking, grondkleur- en kwaliteit, maar is ook positief beinvloed deur grondgebruiksgeskiedenis, die gebruikswaarde van natuurlike en gewassoorte, die kennis van gewaskwaliteite, die kennis van die interaksie tussen gewasse en tussen gewasse en natuurlike plantsoorte, die boomgrootte van boomsoorte wat gebruik word, die toekomstige gebruik van ‘n huidige grondgebruik, die beraamde grondgebruik vir eie gebruik en vir toegang tot die markte.

[pt] A indústria de Petróleo enfrenta uma nova realidade com foco na integração de pessoas, processos e tecnologias, que possibilita a tomada de decisão de forma mais rápida e consequente otimização da operação, emergindo assim o conceito de Operações Integradas. Neste âmbito, as principais empresas mundiais desta indústria possuem programas dedicados à integração operacional da sua cadeia. Os primeiros ambientes criados eram simplesmente derivados do conceito de salas de controle operacional, onde a equipe podia monitorar a operação e realizar comunicação com o pessoal localizado remotamente. Atualmente, as empresas reconhecem que, além do valor agregado dos ambientes de colaboração integrados, a integração operacional exige cuidado, avaliação, design e planejamento da implementação, para garantir que esses ambientes se tornem uma plataforma para melhorar a comunicação, subsidiar as melhores decisões, permitir alta qualidade das análises e efetivamente usar um pool de recursos especialistas para suportar diversas operações simultaneamente. Com base neste contexto, o objetivo desta dissertação é apresentar um modelo de gestão para implantação de um centro de provimento logístico offshore integrado. O modelo foi proposto com base em uma pesquisa-ação realizada em uma unidade de um importante player da indústria de petróleo. O trabalho ressalta os principais motivadores, abordagens, vantagens e desvantagens, indicadores de desempenho que podem ser constituídos, riscos e demais fatores críticos na adoção do modelo de gestão de um centro de provimento logístico offshore integrado. O modelo foi elaborado de forma a ser uma abordagem de gestão eficiente para a mitigação das principais causas de variação nos processos logístico da empresa analisada. A adoção de um modelo como o proposto representa uma ruptura em detrimento às práticas de gestão atuais na maioria das empresas, e, portanto, abordagens não convencionais de gestão de riscos e gestão da mudança são salientadas na dissertação. Por fim, questões inerentes ao delineamento do modelo conceitual para um modelo que se aproxime da realidade para a implantação são abordadas e analisadas. / [en] The oil industry has been facing a new reality and its focus lies in people s integration, processes and technologies which enable decisions to be taken in a faster way, which optimizes the operation and originates, therefore, the Integrated Operation concept. Taking this scenario into account, the main worldwide companies related to this industry are ready to offer programs which are dedicated to the operational integration of this chain. The first environments stemmed from the concept of the operational control rooms, where the team could monitor the operation and perform communication remotely. Nowadays, companies recognize that, besides the integrated value of the integrated collaboration environments, the operation integration demands care, evaluation, design and implementation planning in order to guarantee that such environments can become a platform which will improve communication, subsidize the best decisions, allow high quality in the analysis and use a pool of expert resources in an efficient manner in order to support several operations simultaneously. Based on this context, the aim of this work is to present a management model for the implementation of a center to provide integrated offshore logistics. The model was proposed based on an action research carried out in an important player unit of the oil industry. The work highlights the main motivations, approaches, advantages and disadvantages, performance indicators which may be constituted, risks as well as other critical factors in the adoption of a management model for the implementation of a center to provide integrated offshore logistics. The model was created with the aim of becoming an efficient management approach for the mitigation of the main variation causes in the logistic processes taking the company analyzed as a reference. The adoption of a model as the one proposed represents a rupture as opposed to the current management practices in most companies, and, therefore, non-conventional approaches in the management of risks and changes are highlighted in this work. Finally, issues inherent to the formulation of the conceptual model for a model which is close to the reality for the implementation are discussed an analyzed.

Made available in DSpace on 2016-04-28T18:22:40Z (GMT). No. of bitstreams: 1 Camila Santiago.pdf: 1680894 bytes, checksum: f5004a041aad98b34afd1811f9bf03b8 (MD5) Previous issue date: 2013-06-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this paper is to critically understand how the actions of participants (students and professor-researcher) contribute or not to collaborative knowledge production in two forums in distance education. This study s theoretical framework is founded on the Socio-Historical-Cultural Activity Theory (VYGOTSKY, 1934; LEONTIEV, 1977; ENGESTRÖM, 1987-2009), based on Knowledge Production, discussed through the Art of Encounter(SPINOZA, 1677) and Zones of Proximal Development (VYGOTSKY, 1934; NEWMAN; HOLZMAN, 2002; MAGALHÃES, 2009-2011), and also on the Argumentation studies (LIBERALI, 1999-2012). In methodological terms, it is inserted in the critical paradigm and organized as a Critical Collaborative Research (MAGALHÃES, 2011), that is premised on the assumption of not only observing and describing contexts, but interfering, comprehending and transforming them, in a single movement. The corpus of this investigation is composed by interactions seen in two discussion forums between the professorresearcher and first-term students who are enrolled in the Portuguese and Spanish distance graduation courses at a university in Great São Paulo. In the perspective of Applied Linguistics, data were analyzed through participants speech materiality, in the light of categories that consider knowledge production in Argumentation. These categories were divided in enunciative (BAKHTIN, 1929), discursive(PONTECORVO, 2005; LIBERALI, in press; PERELMAN; OLBRECHTS-TYTECA, 1958) and linguistic categories (LIBERALI, in press; KOCH, 2006). This survey results point out to five manners of managementthat enable the movement of participants voices and collaborative production of knowledge. Moreover, they also show that collaborative production not always happens due to lack of discussion wrap up, negotiation and interlacing of voices / Este trabalho tem por objetivo compreender criticamente de que maneira as ações dos participantes (alunos e professora-pesquisadora) contribuem ou não para a produção colaborativa de conhecimento em dois fóruns na educação a distância. O recorte teórico está fundamentado na Teoria da Atividade Sócio-Histórico-Cultural (VYGOTSKY, 1934; LEONTIEV, 1977; ENGESTRÖM, 1987-2009), com bases na Produção de Conhecimento, discutida a partir da Arte do Encontro (SPINOZA, 1677) e da criação de Zonas de Desenvolvimento Proximal (VYGOTSKY, 1934; NEWMAN; HOLZMAN, 2002; MAGALHÃES, 2009-2011), e nos estudos da Argumentação (LIBERALI, 1999-2012).Em termos metodológicos, está inserido no paradigma crítico e organizada como uma Pesquisa Crítica de Colaboração (MAGALHÃES, 2009-2012),que tem como pressuposto não apenas observar e descrever contextos, mas interferir neles, compreendendo-os e transformando-os, em um movimento único. O corpus de análise constitui-se de interações entre professora-pesquisadora e alunos em dois fóruns de discussão do Período 1 dos cursos de Letras Língua Portuguesa e Língua Estrangeira Espanhol a distância de uma universidade da Grande São Paulo. Na perspectiva da Linguística Aplicada, os dados foram analisados por meio da materialidade nas falas dos participantes, à luz de categorias que consideram a produção de conhecimento na Argumentação. Essas categorias foram divididas em categorias enunciativas(BAKHTIN, 1929),discursivas (PONTECORVO, 2005; LIBERALI, no prelo; PERELMAN; OLBRECHTS-TYTECA, 1958) e linguísticas (LIBERALI, no prelo; KOCH, 2006). Os resultados desta pesquisa apontam para cinco modos de gestão que possibilitam a movimentação das vozes dos participantes e a produção colaborativa de conhecimento. No entanto, expressam também que a produção colaborativa nem sempre acontece devido à falta de fechamento nas discussões, de negociações e de entrelaçamento das vozes

The issue of sediment removal from the San Gabriel Mountains has been a complex issue that has created problems with beach replenishment, habitat destruction and the need to spend millions of dollars at regular intervals to avoid safety hazards. Most recently 11 acres of riparian habitat, including 179 oaks and 70 sycamores, were removed for sediment placement. Other sites including Hahamongna Watershed Park and La Tuna Canyon also face a similar fate. This thesis questions: How did we get to this point of destroying habitat to dump sediment which is viewed as waste product? What are the barriers for creating long term solutions and progressive change? What are some other options? And how should we move forward? The issues with sediment management have stemmed from regulatory compliance issues, adversarial relationships within agencies and among NGO's and the public, and the lack of a comprehensive long-term plan to prevent further habitat loss and other sediment removal issues. A recommendation includes looking at a community forestry model to include a wide cross-section of the community, NGO's and government agencies to come up with a long term comprehensive and progressive solution.

Submitted by Fabiany Feitosa (fabiany.sousa@ufba.br) on 2017-03-21T12:51:23Z No. of bitstreams: 1 Pedro Henrique Gomes Jatobá.pdf: 32486392 bytes, checksum: fd90d6b0b76344c2870e47a6e6954277 (MD5) / Approved for entry into archive by Maria Angela Dortas (dortas@ufba.br) on 2017-03-21T18:06:37Z (GMT) No. of bitstreams: 1 Pedro Henrique Gomes Jatobá.pdf: 32486392 bytes, checksum: fd90d6b0b76344c2870e47a6e6954277 (MD5) / Made available in DSpace on 2017-03-21T18:06:37Z (GMT). No. of bitstreams: 1 Pedro Henrique Gomes Jatobá.pdf: 32486392 bytes, checksum: fd90d6b0b76344c2870e47a6e6954277 (MD5) / A economia da cultura tem se tornado, nas últimas décadas, um importante vetor produtivo e de inclusão social na economia brasileira. Dentre as políticas públicas que estimulam a organização produtiva na cultura, destacam-se o Programa Cultura Viva e as ações de fomento da Secretaria de Economia Criativa, ambos ligados ao Ministério da Cultura. Mesmo beneficiados com incentivos públicos, os empreendimentos comunitários têm dificuldades em acessar o mercado cultural do seu território, formar público e dominar as tecnologias da informação necessárias a sua sustentabilidade. O desenvolvimento de ambientes virtuais de aprendizagem e gestão colaborativa, adaptado à realidade desses grupos, pode ser bem sucedido quando os futuros usuários dos empreendimentos comunitários são capacitados para utilizar a nova solução em paralelo ao seu desenvolvimento. A pesquisa participante junto a Produtora Colabor@tiva.PE na Universidade Federal de Pernambuco e a pesquisa-ação realizada Universidade LIVRE de Teatro Vila Velha na Bahia, analisam como essas produtoras culturais colaborativas conseguiram se beneficiar de novos suportes digitais em seus processos de gestão interna e formação continuada. A colaboração desses usuários na comunidade de desenvolvimento da plataforma CORAIS possibilitou aprimorar as ferramentas de groupware existentes e desenvolver novas funcionalidades como a gestão transparente de uma moeda social digital. / The culture economy has become in the last decades one of the most important productive and social inclusion vectors on Brazilian economy. Among the public finance actions made by the government the main actions that support productive organization on the cultural groups are the Points of Culture network and the creative economy secretary, both related do the Minister of Culture of Brazil. Even the institutions that received public investments are showing difficulties in access in the local market create and maintain consumers have access and learn how to use information technology that is necessary to achieve economical sustainability. The development of collaborative management and learning virtual environments customized to these realities are only possible when these groups learn how to use free software tools in their internal activities. The study of the Produtora Colabor@tiva.PE in Recife at the Federal University of Pernambuco and the Universidade LIVRE de Teatro Vila Velha in Salvador, Bahia, part of this research execute an analysis about how this collaborative cultural producers got better results by adopting virtual environments. The participation of these groups in the CORAIS platform development community made possible that the existing groupware tools and develop new solutions as the public management of a local digital currency.

No description available.

Platforms for publication and collaborative management of data, such as Data.gov or Google Fusion Tables, are a new trend on the web. They manage very large corpora of datasets, but often lack an integrated schema, ontology, or even just common publication standards. This results in inconsistent names for attributes of the same meaning, which constrains the discovery of relationships between datasets as well as their reusability. Existing data integration techniques focus on reuse-time, i.e., they are applied when a user wants to combine a specific set of datasets or integrate them with an existing database. In contrast, this paper investigates a novel method of data integration at publish-time, where the publisher is provided with suggestions on how to integrate the new dataset with the corpus as a whole, without resorting to a manually created mediated schema or ontology for the platform. We propose data-driven algorithms that propose alternative attribute names for a newly published dataset based on attribute- and instance statistics maintained on the corpus. We evaluate the proposed algorithms using real-world corpora based on the Open Data Platform opendata.socrata.com and relational data extracted from Wikipedia. We report on the system's response time, and on the results of an extensive crowdsourcing-based evaluation of the quality of the generated attribute names alternatives.

Dans cette thèse, nous nous sommes intéressés aux protocoles pair-à-pair (P2P), qui représentent une solution prometteuse pour la diffusion et le partage de données à faible coût sur Internet. Nous avons mené, dans un premier temps, une étude comportementale de différents protocoles P2P pour le partage de fichier (distribution de contenus sans contrainte de temps) puis le live. Dans la première étude centréesur le partage de fichier, nous avons montré l’impact d’Hadopi sur le comportement des utilisateurs et discuté l’efficacité des protocoles en fonction du contenu et l’efficacité protocolaire, en se basant sur les choix des utilisateurs. BitTorrent s’est nettement démarqué au cours de cette étude, notamment pour les grands contenus. En ce qui concerne le live, nous nous sommes intéressés à la qualité de servicedu réseau de distribution live Sopcast, car plus de 60% des événements live diffusés en P2P le sont sur ce réseau. Notre analyse approfondie de ces deux modes de distribution nous a fait nous recentrer sur BitTorrent, qui est à la base de tous les protocoles P2P Live, et est efficace en partage de fichier et complètement open source. Dans la seconde partie de la thèse, nous avons proposé et implémenté dansun environnement contrôlé un nouveau protocole sur la base de BitTorrent avec des mécanismes protocolaires impliquant tous les pairs dans la gestion du réseau. Ces nouveaux mécanismes permettent d’augmenter l’efficacité du protocole via une meilleure diffusion, tant pour le live que le partage de fichier, de métadonnées (la pièce la plus rare) et via une méthode dite de push, par laquelle un client va envoyer du contenu aux pairs les plus dans le besoin / In this study, we focused on peer-to-peer protocols (P2P), which represent a promising solution for data dissemination and content delivery at low-cost in the Internet. We performed, initially, a behavioral study of various P2P protocols for file sharing (content distribution without time constraint) and live streaming. Concerning file sharing, we have shown the impact of Hadopi on users’ behavior and discussed the effectiveness of protocols according to content type, based on users’ choice. BitTorrent appeared as the most efficient approach during our study, especially when it comes to large content. As for streaming, we studied the quality of service of Sopcast, a live distribution network that accounts for more than 60% of P2P broadcast live events. Our in-depth analysis of these two distributionmodes led us to focus on the BitTorrent protocol because of its proven efficiency in file sharing and the fact that it is open source. In the second part of the thesis, we proposed and implemented a new protocol based on BitTorrent, in a controlled environment. The modifications that we proposed allow to increase the efficiency of the protocol through improved dissemination of metadata (the rarest piece), both for live and file sharing. An enhanced version is introduced with a push method, where nodes that lag behind receive an extra service so as to improve the overall performance