Submitted by Alisson Mota (alisson.davidbeckam@gmail.com) on 2015-06-24T21:17:11Z No. of bitstreams: 1 Dissertação - Silvino Francisco da Silva Filho.doc: 4714496 bytes, checksum: 49114af18bc6fa7c6b773c1c90cee9bf (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-26T17:45:09Z (GMT) No. of bitstreams: 1 Dissertação - Silvino Francisco da Silva Filho.doc: 4714496 bytes, checksum: 49114af18bc6fa7c6b773c1c90cee9bf (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-26T18:02:40Z (GMT) No. of bitstreams: 1 Dissertação - Silvino Francisco da Silva Filho.doc: 4714496 bytes, checksum: 49114af18bc6fa7c6b773c1c90cee9bf (MD5) / Made available in DSpace on 2015-06-26T18:02:40Z (GMT). No. of bitstreams: 1 Dissertação - Silvino Francisco da Silva Filho.doc: 4714496 bytes, checksum: 49114af18bc6fa7c6b773c1c90cee9bf (MD5) Previous issue date: 2009-06-16 / In the modern world is more and more above all intense the search that you/they make the companies to reach full efficiency, resulting in stable processes, improving the quality of the product with significant cost reduction. However, even in spite of such efforts, a concern to disturb such organizations is materialized in the occurrence of defects (scrap) that, it demands like this the reality, they should be minimized, in other words, they ought to reduce their percentile of occurrence. The procedure methodological employee in the work, was DMAIC (Define, Measure, Analyze, Improve e Control).This work, therefore, he/she has as objective evaluate a model of process administration implanted in a company of the Industrial Pole of Manaus - PIM. The development of this work was due to the need of reducing the index of defects and to stabilize the process of a certain department producing CRT. This inconvenience made possible the use and application of the tool Six Sigma as main allied in the resolution of the problems. With it was possible to define, to measure, to analyze, to get better and to control the process, denominated DMAIC. In the sequence, the model was evaluated taking into account some relevant variables (temperatures and specifications), that were analyzed to verify the acting of the process in relation to the quality of the pieces. The result shows that the quality of the pieces presented after the implantation of the tool in the process was satisfactory. Six Sigma is very much used tool by the company studied in all their departments to reaching their goals, such that the research allowed one to conclude that the tool is revealed useful to the significant reduction of the percentile of scrap. / Modernamente é cada vez mais intensa a busca que fazem as empresas para atingir plena eficiência, resultando em processos estáveis, sobretudo melhorando a qualidade do produto com significativa redução de custo. Contudo, mesmo a despeito de tais esforços, uma preocupação a inquietar tais organizações encontra-se materializada na ocorrência de defeitos (scrap) que, assim exige a realidade, devem ser minimizados, ou seja, terem reduzidos seus percentuais de ocorrência. O procedimento metodológico empregado neste trabalho foi o DMAIC (Define, Measure, Analyze, Improve e Control). Este trabalho, portanto, tem como objetivo avaliar um modelo de gestão de processo implantado em uma empresa do Pólo Industrial de Manaus – PIM. Ademais, o desenvolvimento deste trabalho se deu em função da necessidade de reduzir o índice de defeitos e estabilizar o processo de um determinado departamento produtor de CRT. Essa inconveniência possibilitou o uso e aplicação da ferramenta Seis Sigma como principal aliada na resolução dos problemas. Com ela foi possível definir, medir, analisar, melhorar e controlar o processo, denominado como DMAIC. Na seqüência, o modelo foi avaliado levando em consideração algumas variáveis relevantes (temperaturas e especificações), que foram analisadas para verificar o desempenho do processo em relação à qualidade das peças. Os resultados mostram que a qualidade das peças apresentadas após a implantação da ferramenta no processo foi satisfatória. O Seis Sigma é uma ferramenta muito utilizada pela empresa estudada, em todos os seus departamentos para atingir suas metas, tendo a pesquisa permitido concluir que a ferramenta revela-se útil à redução significativa do percentual de scrap.

A industrialização gerou riqueza, mas também gerou a poluição ambiental pondo em risco as condições de vida no planeta. A produção mais limpa é uma metodologia de gestão para a prevenção da poluição nas manufaturas. A fim de difundir essa metodologia, foram criadas redes inter-organizacionais em diversas regiões do mundo para promover e implementar a produção mais limpa. No entanto, a difusão da produção mais limpa se confronta com barreiras organizacionais persistentes na américa latina como a resistência à mudança, falta de liderança, falta de formação de competências práticas, falta de suporte interno, falta de priorização e falta do efeito multiplicador. Isso sugere que, atualmente, tais redes especializadas nos aspectos técnicos da gestão ambiental não devem estar suficientemente capacitadas na gestão das variáveis organizacionais para a difusão da produção mais limpa. Como um primeiro passo rumo à compreensão destas variáveis, essa tese analisa as redes internas, dentro de uma grande corporação multinacional norte americana. A implementação de uma estrutura matricial para a gestão de projetos pela metodologia seis sigma estimulou os fluxos de conhecimento dos relacionamentos pessoais nas redes internas para mobilizar e multiplicar os conhecimentos tácitos aptos a prevenir a poluição. Deste modo, o desempenho do programa de produção mais limpa corporativo mais do que dobrou mundialmente e viabilizou-se que a subsidiária brasileira participasse do programa com seus primeiros projetos. As técnicas estatísticas comprovaram que a capacidade organizacional para a gestão de projetos tem poder explicativo para o desempenho do programa de produção mais limpa. Por fim, a modelagem qualitativa descreve a integração entre a estrutura matricial oficial e as redes internas de relacionamentos pessoais e propõe um modelo organizacional, no qual o âmbito global da infra-estrutura e o âmbito local das redes auto-projetadas para a execução dos projetos são interligados por um terceiro âmbito representado pelos fluxos dinâmicos de conhecimento das redes internas. / The industrialization created wealth but also generated environmental pollution causing risk for the planet life conditions. Cleaner production is a management methodology for pollution prevention in manufactures. Inter-organizational networks to diffuse this methodology were created in many regions of the world, in order to promote and implement cleaner production. However, the diffusion of cleaner production is confronted with recurrent organizational barriers in latin america as the resistance to change, insufficient leadership, insufficient development of practical skills, insufficient internal support, insufficient prioritization and insufficient multiplication effect. This suggests that currently those networks specialized in the technical issues of environmental management may not be sufficiently skilled to manage the organizational variables for the cleaner production diffusion. As a first step towards the understanding of those variables, in this thesis, the internal networks inside a big north american multinational corporation are analyzed. The implementation of a matrix structure for project management with the six sigma methodology stimulated the knowledge flows of the personal relationships in the internal networks to mobilize and diffuse the tacit knowledge needed to prevent pollution. Thus, the performance of the corporate cleaner production program more than doubled worldwide and also made it feasible to the brazilian subsidiary to participate in this program with its first projects. The statistical techniques proved that the organizational capacity for project management has explaining power to the performance of the cleaner production program. Finally, the qualitative modeling describes the integration between the matrix structure and the internal networks of personal relationships and it is proposed an organizational model, in which the global infra-structure dimension and the local self-designed networks dimension to the projects execution are interconnected by a third organizational dimension represented by the dynamic knowledge flow of the internal networks.

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The dissertation investigates the issues of analyzing a digital Sigma-Delta digital-to-analog converter (DAC) for audio power amplifiers. The main objects of research include a digital Sigma-Delta audio power DAC, improvement of its structure and an experimental research. The primary purpose of the dissertation is to suggest methods for improvement the structure of digital Sigma-Delta audio power DAC interpolator and the converter analysis. / Disertacijoje nagrinėjami Sigma-Delta skaitmeniniai-analoginiai (skaičiaus-analogo, SA) keitikliai garso galios stiprintuvams. Pagrindinis tyrimų objektas – skaitmeninis Sigma-Delta garso galios SA keitiklis, jo sandaros tobulinamas bei eksperimentinis tyrimas. Disertacijos tikslas – pasiūlyti skaitmeninio Sigma-Delta garso galios SA keitiklio interpoliatoriaus struktūros tobulinimo bei keitiklio tyrimo metodus.

Statistisk processtyrning, SPS, är ett välkänt verktyg som används för kvalitetsförbättringar inom organisationer världen över. De senaste åren har tillverkande organisationer tenderat att gå mot kortare serier, vilket medför en problematik när de vill tillämpa statistiska metoder som är utvecklade för traditionell masstillverkning. Framgångsfaktorer för implementering av SPS vid små serier är ett relativt outforskat område och kräver därför ytterligare forskning. Syftet med denna studie var att ta fram en modell över hur SPS framgångsrikt kan implementeras av organisationer med små serier och en stor detaljflora. För att besvara syftet genomfördes en fallstudie med både kvantitativ och kvalitativ metod. Deltagande observationer och en workshop med 15 deltagare utfördes för att identifiera existerande variationer samt definiera nuläget i det avgränsade produktionsflödet, vars processer studerades i studien. Tre produktfamiljer och kritiska parametrar som representerade produktkvalitén valdes ut för att följas upp i styrdiagram. En mätsystemanalys utfördes för att undersöka om de mätdon som i stor utsträckning användes för kvalitetskontroll i processen var tillförlitliga. Styrdiagram upprättades anpassade för små serier och statistiska analyser utfördes för att undersöka om SPS var en användbar metod för kvalitetsförbättringar i processer med små serier. En kvalitativ benchmark med fyra deltagande organisationer utfördes även för att ta del av deras erfarenheter relaterat till implementering och arbete med SPS.  Resultatet visade att den studerade organisationen behöver utföra förändringar gällande arbetsmetoder för kvalitetskontroll samt hantering av processer och mätsystem. Det finns även behov av ett omfattande förbättringsarbete, för att eliminera det flertalet orsaker till systematiska variationer som identifierades påverka processerna och produktkvalitén. Dessa förändringar krävs innan en implementering av SPS kan genomföras. Verktyg inom SPS visade sig med framgång kunna användas för att förbättra processer med små serier, vid användning av standardiserade styrdiagram som möjliggör analys av flera produkter i samma diagram. Processer med små serier och en stor detaljflora medför en utökad komplexitet vid statistiska analyser och visar tecken på ett flertal svårigheter som ökar risken för en fallerad implementering.  Utifrån analyser av det kvalitativa och kvantitativa resultatet skapades en modell med 15 framgångsfaktorer för implementering av SPS vid små serier. Faktorerna bör följas av organisationer med små serier som vill lyckas med att implementera SPS. Framgångsfaktorerna är följande: (1) Var beredd på en kulturförändring som kräver att SPS vävs in i hela organisationen, (2) Förmedla ett tydligt mål och hållbar strategi för arbetet med SPS, (3) Skapa ett utbrett engagemang i hela organisationen, (4) Utse en SPS-koordinator, (5) Inför utbildning och uppföljning från start, (6) Skapa tvärfunktionella team, (7) Främja samarbete och delaktighet under förbättringsarbetet, (8) Ställ krav på ett dugligt mätsystem, (9) Utför en pilotstudie där det finns intresse, (10) Identifiera kritiska processer, produktfamiljer och parametrar, (11) Börja med att lära känna processerna, (12) Upprätta standardiserade styrdiagram, (13) Tolkning och analys av styrdiagram utförs enligt Montgomerys metod för statistiska analyser, (14) Sträva efter stabila processer, (15) Utför kontinuerlig uppföljning. / Statistical process control, SPC, is a widely used technique for quality improvements by companies all over the world. The current trend in manufacturing organizations is directed towards shorter productions runs, which cause problems when applying traditional statistical methods developed for SPC on mass production runs. The critical factors for a successful implementation of SPC on short runs are still not fully explored and require further research. The main purpose of this study was to present a conceptual framework that illustrates the successful implementation of SPC in organizations with short runs and extensive product portfolio. In order to answer the research questions, a case study research methodology with both quantitative and qualitative methods was used. Participant observations and a workshop including 15 participators were performed in order to identify existing process variability’s and current state of the studied production processes.  Three product families and key quality characteristics of each product were chosen to be monitored in control charts, based on scrap costs and staff experiences of the production process.  A measurement system analysis was used to determine if the gauges, used to make measurement quality controls, were capable. Control charts were constructed and adjusted to short production runs. Statistical analysis was then made on the information gathered through the control charts to determine if statistical tools within SPC was useful for quality improvements on short production runs.  Also a qualitative benchmark was performed with four manufacturing companies to take part of their experiences and knowledge related to the implementation and application of SPC.  The findings indicate that the studied organization needs to improve working methods related to quality inspections and monitoring of the production processes. The organization also needs to improve the measurement system and make an extensive work of improvement to reduce the many identified special causes of variation that affects the processes and product quality, before implementing SPC in the organization. Findings showed that SPC tools and techniques successfully can be adopted to improve short run production processes when using standardized control charts for different product types. Short run production processes involve more complex statistical analysis which could inhibit the success of an implementation of SPC.   The analysis of the qualitative and quantitative findings resulted in a framework including 15 critical success factors for the implementation of SPC in short production runs. All the following critical success factors should be taken into account by organizations with short runs that aspire a successful implementation of SPC: (1) Be ready to make a cultural change including the recognition of the importance of SPC within the whole organization, (2) Communicate a clear goal and long-term strategy, (3) Create motivation and commitment from top management to operators on the shop floor, (4) Select a SPC coordinator, (5) Introduce a training programme with feedback from start, (6) Create cross-functional teams, (7) Stimulate cooperation and participation within the work of improvements, (8) Ensure a capable measurement system, (9) Perform a pilot project with enthusiastic employees, (10) Identify critical processes, product families and key quality characteristics, (11) Focus on exploring process behaviors, (12) Construct standardized control charts, (13) Interpret and analyze control charts according to Montgomery’s method for statistical analysis, (14) Attempt to obtain processes in control, (15) Perform continuous follow ups.

Three methodologies are associated with production optimisation, namely, Theory of Constraints (TOC), Lean and Six Sigma – and each boasts with a number of success stories. This dissertation addresses the possibility of implementing all three these methodologies in a specific sequence at an organisation and also sets out to determine the impact of this implementation. A literature survey was conducted on all three stand-alone methodologies as well as on the combined methodology, which is called the Theory of Constrains Lean Six Sigma (TLS). TLS literature suggests that TOC should be implemented first with a view to identify the constraint in an organisation. Lean implementation should follow in order to eliminate any waste in the organisation. Lastly, Six Sigma should be implemented to optimise the process variability. TOC literature explains that The Goal of any organisation is to make money. All other objectives are only the means of achieving The Goal. The literature further indicates that the constraint in any organisation determines the drumbeat, and that this constraint should be managed by means of the Drum-Buffer-Rope methodology. Lean literature points towards 14 Management Principles by means of which an organisation should be managed in order to become a Lean organisation, while Six Sigma literature is concerned with the DMAIC (Define-Measure-Analyse-Improve-Control) methodology used for improvement projects and the belt system that is used to manage these improvement projects. Jonker Sailplanes, a sailplanes manufacturer in Potchefstroom, South Africa, was used as a case study for the implementation of TLS. A description is given of the processes and procedures that were followed before and after the implementation of TLS. The TLS methodology had to be adapted in order to meet the specific needs of Jonker Sailplanes into an adapted 14-step TLS implementation plan. After implementing TOC and Lean at Jonker Sailplanes, it was found that the organisation was not ready for the transition from Lean projects to Six Sigma projects. The implementation of Six Sigma was therefore referred for future research. One of the most significant findings of the current study was the very positive impact that the implementation of TLS had on the organisation: the production tempo (throughput) of the organisation has increased while the operating expenses per aircraft have decreased. This confirms that the profit per aircraft has increased. A critical evaluation of the implementation of the TLS methodology can therefore maintain that the implementation of TLS at Jonker Sailplanes was a success since the production tempo (throughput) and the organisational profit were increased and the implementation of the methodology was done with relative ease. In terms of interpreting results it was also necessary to set out how Jonker Sailplanes proceeded from a prototyping environment to a production setup, and how specifically identifying the constraint helped to achieve this transition. Furthermore, is it argued that when Lean is implemented before TOC, this could move the organisation away from The Goal, which is to make money. The interpretation of findings suggests that the procedure followed at Jonker Sailplanes was the most appropriate one. Finally, recommendations are made for future studies in terms of how to further improve the impact of the TLS implementation at Jonker Sailplanes. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2011.

Three methodologies are associated with production optimisation, namely, Theory of Constraints (TOC), Lean and Six Sigma – and each boasts with a number of success stories. This dissertation addresses the possibility of implementing all three these methodologies in a specific sequence at an organisation and also sets out to determine the impact of this implementation. A literature survey was conducted on all three stand-alone methodologies as well as on the combined methodology, which is called the Theory of Constrains Lean Six Sigma (TLS). TLS literature suggests that TOC should be implemented first with a view to identify the constraint in an organisation. Lean implementation should follow in order to eliminate any waste in the organisation. Lastly, Six Sigma should be implemented to optimise the process variability. TOC literature explains that The Goal of any organisation is to make money. All other objectives are only the means of achieving The Goal. The literature further indicates that the constraint in any organisation determines the drumbeat, and that this constraint should be managed by means of the Drum-Buffer-Rope methodology. Lean literature points towards 14 Management Principles by means of which an organisation should be managed in order to become a Lean organisation, while Six Sigma literature is concerned with the DMAIC (Define-Measure-Analyse-Improve-Control) methodology used for improvement projects and the belt system that is used to manage these improvement projects. Jonker Sailplanes, a sailplanes manufacturer in Potchefstroom, South Africa, was used as a case study for the implementation of TLS. A description is given of the processes and procedures that were followed before and after the implementation of TLS. The TLS methodology had to be adapted in order to meet the specific needs of Jonker Sailplanes into an adapted 14-step TLS implementation plan. After implementing TOC and Lean at Jonker Sailplanes, it was found that the organisation was not ready for the transition from Lean projects to Six Sigma projects. The implementation of Six Sigma was therefore referred for future research. One of the most significant findings of the current study was the very positive impact that the implementation of TLS had on the organisation: the production tempo (throughput) of the organisation has increased while the operating expenses per aircraft have decreased. This confirms that the profit per aircraft has increased. A critical evaluation of the implementation of the TLS methodology can therefore maintain that the implementation of TLS at Jonker Sailplanes was a success since the production tempo (throughput) and the organisational profit were increased and the implementation of the methodology was done with relative ease. In terms of interpreting results it was also necessary to set out how Jonker Sailplanes proceeded from a prototyping environment to a production setup, and how specifically identifying the constraint helped to achieve this transition. Furthermore, is it argued that when Lean is implemented before TOC, this could move the organisation away from The Goal, which is to make money. The interpretation of findings suggests that the procedure followed at Jonker Sailplanes was the most appropriate one. Finally, recommendations are made for future studies in terms of how to further improve the impact of the TLS implementation at Jonker Sailplanes. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2011.

Le récepteur sigma-1 est une protéine chaperonne active dans des tissus lésés. Le récepteur sigma-1 est principalement exprimé dans le cerveau et joue un rôle neuroprotecteur dans l’ischémie ou les maladies neurodégénératives. Le récepteur sigma-1 est également exprimé dans des lignées cellulaires cancéreuses et des travaux récents suggèrent sa participation dans la prolifération et l’apoptose. Cependant, son rôle dans la carcinogenèse reste à découvrir. Les canaux ioniques sont impliqués dans de nombreux processus physiologiques (rythme cardiaque, influx nerveux, …). Ces protéines membranaires émergent actuellement comme une nouvelle famille de cibles thérapeutiques dans les cancers. Au cours de ma thèse, j’ai montré que le récepteur sigma-1 régule l’activité du canal potassique voltage-dépendent hERG et du canal sodique voltage-dépendent Nav1.5 respectivement dans des cellules leucémiques et des cellules issues de cancer du sein. J’ai également montré que le récepteur sigma-1, à travers son action sur l’adressage du canal hERG, augmente l’invasivité des cellules leucémiques en favorisant leur interaction avec le microenvironnement tumoral. Ces résultats mettent en évidence le rôle du récepteur sigma-1 sur la plasticité électrique des cellules cancéreuses et suggèrent l’intérêt de cette protéine chaperonne comme cible thérapeutique potentielle pour limiter la progression tumorale. / The sigma-1 receptor is a chaperone protein active in damaged tissues. The sigma-1 receptor is mainly expressed into brain and have a neuroprotective role in ischemia and neurodegenerative diseases. The sigma-1 receptor is also expressed into cancer cell lines and recent investigations suggest its involvement into proliferation and apoptosis. However, its role in carcinogenesis remains to delineating. Ion channels are involved in numerous physiological processes (heart beating, nervous influx, …). These membrane proteins currently emerge as a new class of therapeutic targets in cancer. During my thesis, I observed that the sigma-1 receptor regulates voltage-dependent potassium channel hERG and voltage-dependent sodium channel Nav1.5 activities respectively into leukemic and breast cancer cell lines. I also demonstrated that the sigma-1 receptor, through its action on hERG channel, increases leukemia invasiveness by promoting interaction with tumor microenvironment. These results highlight the role of the sigma-1 receptor on cancer cell electrical plasticity and suggest this chaperone protein as a potential therapeutic target to limit tumor progression.

Orientador: Otávio José de Oliveira / Banca: Messias Borges Silva / Banca: José Antônio Perrella Balestieri / Banca: Márcio Cardoso Machado / Banca: Eduardo Ferro dos Santos / Resumo: Lean Six Sigma (LSS) é uma estratégia de melhoria contínua usada para aumentar a eficiência e eficácia dos processos produtivos a partir da eliminação de desperdícios e redução da sua variabilidade. Embora existam pesquisas sobre esta metodologia em empresas do setor manufatureiro, poucos estudos são direcionados para a sua aplicação no setor calçadista. Pelo exposto, o objetivo deste trabalho consiste em diretrizes para implementação do LSS em Micro, Pequenas e Médias Empresas (MPME's) de calçados. Para direcionar a realização de oito estudos de casos em MPME's calçadistas foram identificados na literatura cientifica os princípios do LSS e verificada a sua aplicação na realidade das empresas estudadas. Os instrumentos de coleta de dados para estes estudos de caso foram entrevistas semiestruturadas com gestores e colaboradores, análise documental e visita in loco. Na análise dos casos foi identificado que as empresas, embora não utilizem o LSS, possuem práticas que podem facilitar sua implementação, assim como há dificuldades que precisam ser superadas para que implementação possa ocorrer de forma eficaz. Tais possibilidades e dificuldades se constituíram como a base das diretrizes elaboradas para implementação do LSS em MPME's. Os princípios do LSS verificados nas MPME's de calçados foram: desenvolver e manter uma filosofia de longo prazo, focar no cliente, desenvolver líderes, desenvolver pessoas e equipes profissionais, desafiar e respeitar a rede de parceiros e fornecedor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Lean Six Sigma (LSS) is a continuous improvement methodology used to increase the efficiency and effectiveness of production processes by eliminating waste and reducing its variability. Although there are researches on this methodology in companies of the manufacturing sector, few studies are directed to its application in the footwear sector. Therefore, the objective of this paper is to propose guidelines for the implementation of LSS in micro, small and medium enterprises of footwear. In order to direct the accomplishment of eight case studies in footwear MSMEs, the principles of LSS were identified in the scientific literature, verified in the reality of the companies studied. The instruments of data collection for these case studies were semi-structured interviews with managers and collaborators, documentary analysis and on-site visit. In the analysis of the cases it was identified that the companies, although they do not use the LSS, have practices that can facilitate their implementation. As well as there are difficulties that need to be overcome so that implementation can take place effectively. These possibilities and difficulties were the basis of the guidelines developed for the implementation of LSS in MSMEs. The LSS principles found in MSMEs for footwear were: to develop and maintain a long-term philosophy, focus on the customer, develop leaders, develop people and professional teams, challenge and respect the network of partners and suppliers, create a culture of continuous improvement, Use LSS tools, pull systems (JIT), focus on the perfection of products, processes and services, eliminate waste and reduce variability. This research contributes to fill the gap in the literature regarding the lack of proposals for the implementation of LSS in MSMEs of footwear (scientific contribution) and allows ... (Complete abstract click electronic access below) / Doutor

Cette thèse a pour sujet une classe de théories des champs intégrables appelées modèles avec fonction twist. Les principaux exemples de tels modèles sont les modèles sigma non-linéaires intégrables, tel le Modèle Principal Chiral, et leurs déformations. Un premier résultat obtenu est la preuve que le modèle dit de Bi-Yang-Baxter, qui est une déformation à deux paramètres du Modèle Principal Chiral, est lui aussi un modèle avec fonction twist. Il est ensuite montré que les déformations de type Yang-Baxter modifient certaines symétries globales du modèle non déformé en symétries de Poisson-Lie. Un autre chapitre concerne la construction d'une infinité de charges locales en involution pour tous les modèles sigma intégrables et leurs déformations : ce résultat repose sur le formalisme général partagé par tous ces modèles en tant que théories des champs avec fonction twist.La seconde partie de la thèse a pour sujet les modèles de Gaudin. Ceux-ci sont des modèles intégrables associés à des algèbres de Lie. En particulier, les théories des champs avec fonction twist sont liées aux modèles de Gaudin associés à des algèbres de Lie affines. Une approche standard pour l'étude du spectre des modèles de Gaudin quantiques sur des algèbres finies est celle de Feigin-Frenkel-Reshetikhin. Dans cette thèse, des généralisations de cette approche sont conjecturées, motivées et testées. L'une d'elles concerne les modèles de Gaudin finis dits cyclotomiques. La seconde porte sur les modèles de Gaudin associés à des algèbres affines. / This thesis deals with a class of integrable field theories called models with twist function. The main examples of such models are integrable non-linear sigma models, such as the Principal Chiral Model, and their deformations. A first obtained result is the proof that the so-called Bi-Yang-Baxter model, which is a two-parameter deformation of the Principal Chiral Model, is also a model with twist function. It is then shown that Yang-Baxter type deformations modify certain global symmetries of the undeformed model into Poisson-Lie symmetries. Another chapter concerns the construction of an infinite number of local charges in involution for all integrable sigma models and their deformations: this result is based on the general formalism shared by all these models as field theories with twist function.The second part of the thesis concerns Gaudin models. These are integrable models associated with Lie algebras. In particular, field theories with twist function are related to Gaudin models associated with affine Lie algebras. A standard approach for studying the spectrum of quantum Gaudin models over finite algebras is the one of Feigin-Frenkel-Reshetikhin. In this thesis, generalisations of this approach are conjectured, motivated and tested. One of them deals with the so-called cyclotomic finite Gaudin models. The second one concerns the Gaudin models associated with affine Lie algebras.