Les organisations virtualisées sous multi-gouvernance sont des organisations co-gouvernées simultanément par plusieurs organisations indépendantes. Les distances organisationnelles et géographiques leur incitent à mettre en place des équipes virtuelles à grande échelle. Ces organisations des acteurs hétérogènes adoptent un mode de contrôle particulier riche d'enseignements pour la théorie du contrôle. En complément du contrôle interorganisationnel, leur système de contrôle est combiné d'un contrôle interactif informel. L'e-collaboration est le mode de travail essentiel. Les objets-frontières jouent un rôle important dans le contrôle interactif informel et dans l'e-collaboration des équipes au-delà des frontières organisationnelles, géographiques et temporelles. / Virtualised organizations with multi-governance are co-governed simultaneously by several independent organizations. Organizational and geographical distances encourage them to set up virtual teams on a large scale. These organizations adopt a particular control mode. In addition to the inter-organizational control, their control system is combined with an informal interactive control. The e-collaboration is their important way of work. The boundary objects play an important role in the and in the informal interactive control and in the e-collaboration, beyond organizational boundaries, geographical and temporal.

Previsões meteorológicas para longos períodos de tempo estão se tornando cada vez mais importantes. A preocupação mundial com as consequências da mudança do clima tem estimulado pesquisas para determinar o seu comportamento nas próximas décadas. Ao mesmo tempo, os passos necessários para definir uma melhor modelagem e simulação do clima e/ou tempo estão longe da precisão desejada. Aumentar o refinamento da superfície terrestre e, consequentemente, aumentar o número de pontos discretos (utilizados para a representação da atmosfera) na modelagem climática e precisão das soluções computadas é uma meta que está em conflito com o desempenho das aplicações numéricas. Aplicações que envolvem a interação de longos períodos de tempo e incluem um grande número de operações possuem um tempo de execução inviável para as arquiteturas de computadores tradicionais. Para superar esta situação, um modelo climatológico pode adotar diferentes níveis de refinamento da superfície terrestre, utilizando mais pontos discretos somente em regiões onde uma maior precisão é requerida. Este é o caso de Ocean-Land-AtmosphereModel, que permite o refinamento estático de uma determinada região no início da execução do código. No entanto, um refinamento dinâmico possibilitaria uma melhor compreensão das condições climáticas específicas de qualquer região da superfície terrestre que se tivesse interesse, sem a necessidade de reiniciar a execução da aplicação. Com o surgimento das arquiteturas multi-core e a adoção de GPUs para a computação de propósito geral, existem diferentes níveis de paralelismo. Hoje há paralelismo interno ao processador, entre processadores e entre computadores. Com o objetivo de extrair ao máximo a performance dos computadores atuais, é necessário utilizar todos os níveis de paralelismo disponíveis durante o desenvolvimento de aplicações concorrentes. No entanto, nenhuma interface de programação paralela explora simultaneamente bem os diferentes níveis de paralelismo existentes. Baseado neste contexto, esta tese investiga como explorar diferentes níveis de paralelismo em modelos climatológicos usando interfaces clássicas de programação paralela de forma combinada e como é possível prover refinamento de malhas em tempo de execução para estes modelos. Os resultados obtidos a partir de implementações realizadas mostraram que é possível reduzir o tempo de execução de uma simulação atmosférica utilizando diferentes níveis de paralelismo, através do uso combinado de interfaces de programação paralela. Além disso, foi possível prover maior desempenho na execução de aplicações climatológicas que utilizam refinamento de malhas em tempo de execução. Com isso, uma malha de maior resolução para a representação da atmosfera terrestre pode ser adotada e, consequentemente, as previsões numéricas serão mais precisas. / Weather forecasts for long periods of time has emerged as increasingly important. The global concern with the consequences of climate changes has stimulated researches to determine the climate in coming decades. At the same time the steps needed to better defining the modeling and the simulation of climate/weather is far of the desired accuracy. Upscaling the land surface and consequently to increase the number of points used in climate modeling and the precision of the computed solutions is a goal that conflicts with the performance of numerical applications. Applications that include the interaction of long periods of time and involve a large number of operations become the expectation for results infeasible in traditional computers. To overcome this situation, a climatic model can take different levels of refinement of the Earth’s surface, using more discretized elements only in regions where more precision are required. This is the case of Ocean-Land- Atmosphere Model, which allows the static refinement of a particular region of the Earth in the early execution of the code. However, a dynamic mesh refinement could allow to better understand specific climatic conditions that appear at execution time of any region of the Earth’s surface, without restarting execution. With the introduction of multi-core processors and GPU boards, computers architectures have many parallel layers. Today, there are parallelism inside the processor, among processors and among computers. In order to use the best performance of the computers it is necessary to consider all parallel levels to distribute a concurrent application. However, nothing parallel programming interface abstracts all these different parallel levels. Based in this context, this thesis investigates how to explore different levels of parallelism in climatological models using mixed interfaces of parallel programming and how these models can provide mesh refinement at execution time. The performance results show that is possible to reduce the execution time of atmospheric simulations using different levels of parallelism, through the combined use of parallel programming interfaces. Higher performance for the execution of atmospheric applications that use online mesh refinement was also provided. Therefore, more mesh resolution to describe the Earth’s atmosphere can be adopted, and consequently the numerical forecasts are more accurate.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-10-31T12:38:07Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) VERSAOFINALDISSERTACAOBRUNOFIGUEIREDO.pdf: 3063476 bytes, checksum: c8babf719687b86ef5dbc4015778c40f (MD5) / Made available in DSpace on 2016-10-31T12:38:07Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) VERSAOFINALDISSERTACAOBRUNOFIGUEIREDO.pdf: 3063476 bytes, checksum: c8babf719687b86ef5dbc4015778c40f (MD5) Previous issue date: 2016-02-16 / FACEPE / Contexto: Multi Level Autonomic Business Process (MABUP) é uma opção para auxiliar no gerenciamento de processos de negócios autonômicos. Ela considera aspectos relativos à variabilidade, compreensibilidade, escalabilidade e Requisitos Não- Funcionais. Contudo, identificamos algumas limitações para adoção da abordagem MABUP, entre elas a necessidade do desenvolvimento de uma ferramenta de apoio que permita não apenas a modelagem dos processos de negócios com características autonômicas, mas também a sua execução. Objetivo: Portanto, nesta dissertação propomos o desenvolvimento da ferramenta MABUPTool, a partir da extensão do framework Activiti, com o objetivo de auxiliar na adoção e compreensão da abordagem MABUP. Método: Após o desenvolvimento da ferramenta foram feitas duas avaliações experimentais com o objetivo de investigar a adoção da abordagem como sua ferramenta de apoio. Os resultados obtidos são promissores uma vez que os dados indicam que a adoção dos elementos estendidos auxilia a compreensão da abordagem MABUP. Conclusões: Para avaliar a qualidade da ferramenta, uma avaliação de usabilidade foi feita e os resultados indicaram que os quatro fatores analisados (satisfação geral, utilidade do sistema, qualidade da informação e qualidade da interface) foram alcançados com sucesso. / Context: Multi-level Autonomic Business Process (MABUP) approach is an option to manage autonomic business processes, it is considers aspects such as to variability, understandability, scalability and Non-Functional Requirements. However, we have identified several limitations for the adoption of MABUP approach. Among then, the need for a supporting tool, that allows not only the modeling of the business process with autonomic characteristics, but also its execution. Objective: Hence, in this dissertation we propose the development of MABUPTool tool, from the extension of Activiti framework, in order to assist in the adoption and understanding of MABUP approach. Method: After the tool development, some experiments were conducted to assess both the adoption of the MABUP approach and its supporting tool. The results indicate that the adoption extended elements enhances the understanding of MABUP approach. Conclusions: To assess the quality of the tool, a usability evaluation was performed and the results shows that all four factors analyzed (overall satisfaction, system utility, quality of information and interface quality) were successfully achieved.

Made available in DSpace on 2015-04-20T12:33:27Z (GMT). No. of bitstreams: 1 wanderson.pdf: 2478946 bytes, checksum: 854238cf4114ab65652ed32f310fab18 (MD5) Previous issue date: 2013-07-05 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / As atuais aplicações embarcadas têm exigido cada vez mais dos sistemas embarcados que por sua vez apresentam inúmeras limitações físicas e de recursos computacionais, sendo a memória um dos recursos mais críticos, devido a sua capacidade de armazenamento ser limitada de acordo com sua área ocupada no sistema. Assim justifica-se o esforço para otimizar o seu uso. Pesquisas têm mostrado que as técnicas de compressão de código servem como uma alternativa para resolver alguns problemas como: espaço, desempenho e consumo de energia nos sistemas embarcados. Esta tese trata da compressão de código dos programas para execução em sistemas embarcados baseados em processadores RISC. Na tese mostra-se que a utilização dos quatro novos métodos propostos e desenvolvidos neste trabalho (CPBARM, HDPB, CCHPB e CC-MLD) resulta em boas taxas de compressão. Implementações eficientes e simples do hardware descompressor também são apresentados. Além disto, um novo tipo de dicionário dividido em níveis também é introduzido por esta tese. O paradigma aplicado por esse novo dicionário consiste em armazenar instruções unitárias e padrões de blocos encontrados no código dos programas ao mesmo tempo e por isto é chamado de Dicionário Multi-Nível. Nas simulações realizadas com os métodos desenvolvidos nesta tese usaram-se alguns programas do benchmark MiBench. As taxas de compressão média obtidas nos métodos variaram de 24,2% a 32%. Assim, os algoritmos propostos oferecem uma melhor exploração da tríade compressão-desempenho-consumo.

En psychologie, le concept de bien-être, composante positive de la santé (Keyes, 2003), possède un long historique de recherche, le positionnant au croisement de plusieurs enjeux : distinction entre les conceptions hédoniste (Diener, 1999) et eudémonique (Ryff, 2014), existence d’une spécificité du bien-être psychologique au travail (Dagenais-Desmarais, 2012), évaluation par questionnaire des dimensions individuelle et collective (Heutte, 2010), étude du lien avec la performance d’équipe (Rousseau, Aubé, & Savoie, 2006), intégration dans les approches multi-niveaux de prévention de la santé au travail (Martin, 2015). Nous postulons qu’un questionnaire interrogeant simultanément l’individu sur son propre bien-être et celui de son équipe apporte à la fois une appréciation juste de ces deux niveaux, tout en intégrant une mesure pronostique de l’efficacité du groupe au travail. Cette proposition de méthode prend la forme d’un questionnaire à double entrée, s’appuyant sur la méthode du « changement de réfèrent » (Chan 1998).L’objectif étant d’éclairer le passage de la mesure du bien-être psychologique au travail du niveau individuel au niveau du groupe, notre démarche de recherche (sous convention CIFRE) participe aux pratiques d’accompagnement et de prévention des problématiques de santé au travail par une focalisation originale sur les équipes de travail.Cinq études, réunissant 1101 réponses de professionnels en activité dans des entreprises et des institutions françaises, ont permis de montrer qu’un processus de comparaison sociale contribue aux réponses du sujet, tout en conservant la bonne qualité psychométrique des échelles de mesure utilisées. Le rapport individu / groupe induit par la méthode, mettant en tension les besoins d’affiliation et de différenciation (Codol, 1973, 1975a, 1975b, 1984 ; Brewer, 1991, 2007, 2012), participe à opérer une mise à distance entre soi et son équipe dans les réponses au questionnaire à double entrée. Ce type de réponse nous offre une nouvelle voie d’analyse en pronostiquant le fonctionnement d’une équipe.Par ailleurs, cette thèse ouvre des perspectives de recherche dans le domaine des mesures multi-niveaux de la santé au travail et appelle un investissement complémentaire sur les processus cognitifs propres à la méthode. / In psychology, the concept of « well-being », a positive component of health (Keyes, 2003), has a long history of scientific investigation, positioning this concept at the crossroads of various issues: distinction between hedonist (Diener, 1999) and eudemonic (Ryff, 2014) conceptions, the presence of a specific psychological wellbeing at work (Dagenais-Desmarais, 2012), questionnaire assessment of individual and collective dimensions (Heutte, 2010), connection with team performance (Rousseau, Aubé & Savoie, 2006), multilevel approaches to health prevention at work (Martin 2015). We postulate that a questionnaire measuring simultaneously both one’s own personal well-being and that of one’s team, provides at the same time a reliable appreciation of these two dimensions and a reliable measurement of team effectiveness/performance. This can be achieved through a “double entry” questionnaire based on the « referent shift » method (Chan 1998). By clarifying the translation of psychological wellbeing at work from the individual to the group level, our research (embedded in CIFRE conventions) participates in preventing and accompanying health issues, through its original focus on working teams.Five studies involving 1101 active workers in corporate and French institution have shown that a process of social comparison does contribute to individual answers, with no impact on the psychometric quality of the of the measurement scales. This relationship individual/group, which juxtaposes affiliative vs differentiative needs (Codol, 1973, 1975a, 1975b, 1984; Brewer, 1991, 2007, 2012), helps operate a distancing between regards to one’s self and one’s team in the answers to the double entry questionnaire. These findings open the way to new analysis, based on forecasting team functioning. Moreover, this dissertation offers a new research perspectives into the multi-level measurement of health at work, and calls for complementary investigations on cognitive processes specific to the selected « matrix » method.

Abstract New forms of environmental governance are implemented with promises associated with more flexible and participatory decision-making. However, resistance towards these ways of doing decisions occurs also in relation to forests in northern Finland. This thesis seeks to explain this resistance and to discuss how participation in the context of multi-level environmental governance can be enhanced. A combination of anthropological fieldwork methods and concepts from environmental politics is used to create a bottom-up research strategy to examine forest governance. Based on theme interviews, planning documents and press releases of various actors, this thesis identifies problems for hybrid forest governance modes, which combine State, market, and civil society actors in decision-making processes. Based on selected topical case studies regarding state-owned commercial forests in Inari, Forest Lapland, Muonio, and Liperinsuo three different governance modes are identified: a State-based mode with a participatory dimension and two ‘pressure’ modes taking place via market-based campaigns of environmental NGOs and local protests. Concerning the protected areas, namely Malla Strict Nature Reserve and the Pallas-Ylläs and Oulanka national parks, one governance mode is identified as taking place on the vertical park managements – international conservation agencies – local resource users axis. A major explanation for resistance towards the different governance modes is that decision-making processes neglect site-specifics. Related problems include missing stakeholders, lack of site-specific discussions in planning processes, generalised concepts used in standardisation practices, engagement of ‘faraway’ stakeholders in decision processes, and lack of transparency. As a result, ‘the site strikes back’ responses, i.e. pressure campaigns, protests, opposition, and rumours have emerged. In order to mitigate resistance, this thesis proposes ways to enhance participation and deliberation in forest governance. However, the utility of these suggestions is challenged by polarised views and a lack of trust between the different parties. Finally, hypotheses explaining resistance towards decision-making are formulated. Also, contributions to environmental anthropology are outlined, and further questions relevant for research on environmental governance are posed. / Tiivistelmä Uudet ympäristöhallinnan muodot lupaavat parempaa kansalaisosallistumista ja joustavuutta päätöksentekoon. Kuitenkin näitäkin hallinnan muotoja vastustetaan myös Pohjois-Suomen metsiin liittyen. Tässä väitöskirjassa pyritään selittämään vastarintaa metsien hallintaa kohtaan valtion omistamissa talousmetsissä ja suojelualueilla. Väitöskirjassa yhdistetään antropologisia kenttätyömenetelmiä ja ympäristöpolitiikan käsitteitä. Pohjaten teemahaastatteluihin, suunnitteludokumentteihin, lehdistötiedotteisiin ja www-sivuihin tämä väitöskirja määrittää ongelmia hybrideille hallinnan ja päätöksenteon muodoille, jotka koostuvat valtioon, markkinoihin ja kansalaisyhteiskuntaan liittyvien toimijoiden vuorovaikutuksesta. Pohjaten ajankohtaisiin metsäkiistoihin Inarissa, Metsä-Lapissa, Muoniossa ja Liperinsuolla kolme erilaista hallinnan muotoa erotellaan: valtiovetoinen hallinnan muoto, johon kansalaisyhteiskunta linkittyy osallistavien prosessien kautta sekä kaksi ”painostusmuotoa”, jotka koostuvat ympäristöjärjestöjen markkinapohjaisista kampanjoista sekä paikallislähtöisistä protesteista. Mallan, Pallas-Ylläksen ja Oulangan suojelualueisiin liittyen määritellään yksi hallinnan muoto, joka muodostuu puistojen hallinnoista, kansainvälisistä suojelutoimijoista sekä paikallisista luonnonkäyttäjistä. Näitä hallinnan muotoja yhdistää se, että niiden kohtaama vastarinta johtuu paikkakohtaisen päätöksenteon puutteista. Ongelmat liittyvät päätöksentekoprosesseista puuttuviin intressiryhmiin, suunnitteluprosesseissa käytyjen keskustelujen yleisluonteisuuteen, yleispätevien käsitteiden käyttöön standardoimisprosesseissa erityisesti suojelualueilla, läpinäkyvyyden puutteeseen sekä kaukaisten toimijoiden osallistumiseen paikallisiin päätöksiin. Näiden ongelmien seurauksena paikkakohtaisuutta ei huomioida riittävästi hallinnassa, mistä seuraa ’paikan vastaisku’ protestien, huhujen, vastustuksen ja kampanjoiden muodossa. Vastarinnan syntymistä voitaisiin ehkäistä parantamalla osallistumista ja neuvottelua, joskaan parannusehdotuksetkaan eivät ratkaise luottamuksen puutteeseen ja osapuolten näkemysten napaistumiseen liittyviä ongelmia. Väitöskirjassa luodaan hypoteeseja, jotka selittävät ympäristöhallinnan kohtaamaa vastarintaa. Lisäksi väitöskirja tarjoaa antia sekä uusia tutkimuskysymyksiä erityisesti ympäristöantropologialle.

Occupational hearing loss resulting from noise exposures encountered in the workplace affects millions of workers and costs hundreds of millions of dollars annually in Workers’ Compensation costs in the United States alone. Some industries have been well studied, and the presence of hazardous noise in the work environment established and documented. The restaurant industry is one in which little current data exists, but in which there may be cause for concern. This work sought to quantify noise exposures for cooks, servers, and dishwashers and to determine whether or not any of these workers are at risk for Noise Induced Hearing Loss. Further, the researchers wanted to know what environmental factors present in the restaurants had the greatest impact on noise exposures for each exposure group. Statistical analysis was conducted on selected factors, and while nearly all were found to have significant effects on noise exposure for servers, only the number of minutes worked explained variance in exposures for cooks and dishwashers when all factors were included in analysis. These two groups are the ones most likely to be overexposed and they typically worked more than 480 minutes on the day the sample was collected. Efforts to control exposure must take these extended shifts into careful account. The study was limited by relatively small sample size, with 124 cooks, 119 servers, and 91 dishwashers employed at nine different restaurants participating. Future efforts to explain and characterize the sources of variation in noise exposure for these three groups should include greater numbers of participants and structure the data in a way that allows the effects of selected factors to be more clearly seen.

This study is based on previous research concluding that sub-national actors now function on a complex arena where the nation state is not the sole and self-evident channel to the European Union. Based on that assumption, the thesis is intended to create understanding of the nature of the relationship between the West Sweden regional office and its Värmland commissioners in the case of regional action. The relationship between the regional office and its members was examined in a case study of open consultation around the EU’s new EU 2020 strategy. The questions posed in the thesis are answered by interviews with representatives of West Sweden and certain Värmland members of that organization. The results of the interviews were then analyzed based on a fusion perspective, which addresses various indicators for regional action. The results of the study show that the West Sweden regional office can assume a clearer role in regional influencing, but also that Region Värmland plays an important role in influencing the EU. In order for Värmland as a region to continue to be able to influence the supranational level forthcoming, its municipalities need to raise their awareness of what the EU does.

Les changements climatiques et l'émission de polluants dans l'environnement sont susceptibles d'entrainer des effets croisés sur les communautés et le fonctionnement des écosystèmes. Les changements de température sont notamment susceptibles de modifier le comportement et la toxicité des polluants, et de sensibiliser les organismes aux stress chimiques. Inversement, l'exposition à des polluants peut diminuer la tolérance thermique des espèces ectothermes comme les poissons. Dans ce contexte, nous avons étudié la réponse d'une espèce modèle de poissons en toxicologie aquatique, le Carassin doré (Carassius auratus), soumis à des stress chimique et thermique individuels et combinés. Pour cela, le carassin doré a été exposé à un cocktail d'herbicides et de fongicides à des concentrations réalistes d'un point de vue environnemental à deux températures pendant 96h ou 16 jours. Les réponses ont été observées de l'échelle moléculaire à l'échelle individuelle par des approches omiques (protéomique et métabolomique), biochimiques (cortisol, biomarqueurs de stress oxydant et allocation cellulaire énergétique), indicielles (indices somatiques et de condition) et comportementales (remaniement sédimentaire, activité, exploration et comportement alimentaire). Les résultats montrent que l'exposition des poissons aux stress chimique et thermique individuels entraine une réponse générale de stress impliquant des compensations biochimiques, énergétiques, physiologiques et comportementales. L'absence d'effets sur la santé générale des carassins suggère la mise en place d'une réponse de stress efficace et adaptée, bien que l'hypoactivité observée chez les poissons exposés aux cocktails de pesticides soit susceptible d'entrainer une diminution de leurs performances et de leur fitness. A l'inverse, les carassins exposés aux stress chimique et thermique combinés montrent une inhibition de la réponse générale de stress, avec des effets antagonistes sur la sécrétion de cortisol, l'induction de certains systèmes de défense antioxydants et la compensation énergétique. Des effets plus importants sont en revanche observés au niveau comportemental ainsi qu'une diminution significative de la condition générale des poissons. Ces résultats montrent que l'augmentation de la température sensibilise les poissons à la contamination de l'eau par les pesticides. L'inhibition de la réponse de stress chez des poissons exposés à des mélanges complexes de pesticides dans un écosystème soumis à de multiples contraintes pose de nombreuses questions pour la conservation des espèces dans l'environnement. / Crossed-effects between climate change and chemical pollutions were identified on community structure and ecosystem functioning. Temperature rising affect the toxic properties of pollutants and the sensitiveness of organisms to chemicals stress. Inversely, chemical exposure may decrease the thermal tolerance of ectothermic species, as fish. In this context, we studied the response of a biological model in aquatic toxicology, the goldfish (Carassius auratus), to individual and combined chemical and thermal stresses. In this aim, we exposed the goldfish to environmental relevant concentrations of herbicide and fungicide mixtures at two temperatures for 96 hours or 16 days. The fish responses were assessed from the molecular level to individual endpoints, including omic approaches (proteomic and metabolomic), biochemical analyses (cortisol, antioxidant defenses, cellular energy allocation), indexes (somatic and condition factors) and behavioral assays (sediment reworking, activity, exploration and feeding). Our results showed that individual chemical or thermal stresses induced a general stress response including biochemical, metabolic, physiological and behavioral compensations. The absence of deleterious effect on the global condition of fish suggested the implementation of an efficient and adaptive stress response, while the hypoactivity of fish exposed to pesticide mixtures could entrain a decreased performance and fitness into the wild. At the opposite, the combined chemical and thermal stresses induced reciprocal inactivation of the stress response, with antagonism effect on cortisol secretion, antioxidant defense induction and metabolic compensation. However, increased effect on behavioral traits and decreased global condition of fish were observed. Our study showed that temperature rising sensitized fish to pesticide exposure. Finally, inhibited stress response in fish exposed to pesticide cocktails raises concerns about species conservation an ecosystem under multiple pressures.

Les travaux de thèse visent à utiliser les modèles éléments finis pour l'optimisation de systèmes multidynamiques. Les modèles éléments finis sont en effet rarement utilisés en optimisation car ils génèrent des temps de calcul trop importants. Pour réduire le temps global d'optimisation, le temps de simulation du modèle lui-même peut être diminué, mais le nombre d'évaluations du modèle peut aussi être limité. Dans cette optique, les stratégies d'optimisation multigranularités sont appliquées, permettant de corriger ou de créer des modèles rapides pour l'optimisation à partir de quelques évaluations d'un modèle initial. Ce modèle est un système multidynamique intégrant un modèle éléments finis. La modélisation d'un tel système est effectuée via la méthode de relaxation des formes d'onde qui permet un couplage efficace en un temps raisonnable. Le temps de calcul est encore réduit par l'application aux modèles éléments finis électromagnétiques de méthodes de réduction de modèle. La méthode de relaxation des formes d'onde est appliquée à la modélisation d'un transformateur. Le transformateur est ensuite optimisé par des méthodes de space mapping et de krigeage. La méthode de relaxation des formes d'onde permet également le couplage d'un modèle électromagnétique non linéaire de type éléments finis avec un redresseur commandé et un modèle thermique éléments finis / These works aim at using finite element models in optimisation of multirate systems. Indeed, the finite element models are rarely used in optimisation because their computation time is too high. To reduce the duration of the optimisation process, simulation time of the model can be reduced, but the number of evaluations of the model can also be limited. In this perspective, multi-level optimisations are applied. They allow to correct or create fast models for the optimisation from a few number of evaluations of an initial model. The model is a multirate system including a finite element model. The modeling of such a system is done by waveform relaxation method which allows an efficient coupling in an acceptable computation time. Computation time is further reduced by applying model order reduction to the finite element models.The waveform relaxation method is applied to the modeling of a transformer. Then the transformer is optimised by space mapping and kriging techniques. The waveform relaxation method also allows the coupling of a finite element type electromagnetic non linear model with a rectifier and a finite element thermal model