L'archivage de données industrielles est un problème complexe : il s'agit de stocker un grand nombre de données sur plusieurs décennies, tout en supportant la charge des insertions temps réel et des requêtes d'extraction et d'analyse. Pour ce type d'application, des produits « de niche » se sont spécialisés pour ce segment du marché : les progiciels d'historisation. Il s'agit de solutions propriétaires avec des coûts de licence de l'ordre de plusieurs dizaines de milliers d'euros, et dont le fonctionnement interne n'est pas dévoilé. Nous avons donc dans un premier temps mis en évidence les spécificités de ces progiciels d'historisation, tant au niveau des fonctionnalités que des performances. Néanmoins, l'archivage de données industrielles peut s'appliquer à des contexte très différents. L'IGCBox par exemple est un mini PC industriel utilisant MySQL pour l'archivage à court terme des données de production des centrales hydrauliques d'EDF. Ce matériel présente quelques spécificités, la principale étant son système de mémoire non volatile basé uniquement sur la technologie flash, pour sa fiabilité importante en milieu industriel et sa faible consommation d'énergie. Les SGBD possèdent pour des raisons historiques de nombreuses optimisations spécifiques aux disques durs, et le manque d'optimisation adaptée aux mémoires flash peut dégrader significativement les performances. Le choix de ce type de mémoire a donc eu des répercussions notables sur les performances pour l'insertion, avec une dégradation importante par rapport aux disques durs. Nous avons donc proposé Chronos, un SGBD dédié à l'historisation de données sur mémoires flash. Pour cela, nous avons en particulier identifié un algorithme d'écriture « quasi-séquentiel » efficace pour accéder à la mémoire, ainsi que des mécanismes de bufferisation et de mise à jour d'index optimisés pour les charges typiques de l'historisation. Les résultats expérimentaux montrent un gain significatif pour les insertions par rapport à des solutions équivalentes, d'un facteur 20 à 54. Chronos est donc une solution compétitive lorsque les insertions correspondent à une proportion importante de la charge soumise au SGBD. En particulier pour les charges typiques des IGCBox, Chronos se distingue en proposant des performances globales améliorées d'un facteur 4 à 18 par rapport aux autres solutions. / Archiving industrial data is a complex issue: a large volume of data has to be stored for several decades while meeting performance requirements for real-time insertions, along with retrieval and analysis queries. For these applications, niche products have specialized in this market segment: data historians. Data historians are proprietary solutions, with license fees of tens of thousands of dollars, and whose internal mechanisms are not documented. Therefore, we first emphasized data historian specificities, with regards to functionalities as much as performance. However, archiving industrial data can occur in very different contexts. IGCBoxes for example are industrial mini PCs using MySQL for short-term data archiving in hydroelectric power stations at EDF. These equipments expose distinctive features, mainly on their storage system based exclusively on flash memory, for its reliability in an industrial environment and its low energy consumption. For historical reasons, DBMS include many hard disk drive-oriented optimizations, and the lack of adjustment for flash memories can significantly decrease performance. This type of memory thus had notable consequences on insert performance, with a substantial drop compared with hard disk drives. We therefore designed Chronos, a DBMS for historization data management on flash memories. For that purpose, we especially identified an efficient “quasi-sequential” write pattern on flash memories, along with buffer and index management techniques optimized for historization typical workloads. Experimental results demonstrate improved performance for insertions over different solutions, by a factor of 20 to 54. Chronos is therefore competitive when insertions make up an extensive part of the workload. For instance, Chronos stands out with the typical workload of IGCBoxes, with global performance improved by a factor of 4 to 18 compared with other solutions.

Made available in DSpace on 2015-04-14T14:26:53Z (GMT). No. of bitstreams: 1 426905.pdf: 260176 bytes, checksum: d2757a4bf9f435928f6d1a1b32eb1e38 (MD5) Previous issue date: 2010-08-30 / Este estudo apresenta uma an?lise sobre a influ?ncia das redes sociais no ?mbito do cr?dito banc?rio, com base no referencial te?rico do capital social. O trabalho investiga como a presen?a da assimetria de informa??o entre os agentes pode modificar os crit?rios utilizados pelo sistema financeiro nas suas pol?ticas de cr?dito. O estudo utiliza entrevistas com gerentes de ag?ncias banc?rias para entender como eles combinam os procedimentos padr?es recomendados pelos respectivos bancos e as informa??es privadas que t?m sobre seus clientes. Os resultados mostram que as rela??es pessoais e de um ambiente de confian?a podem mudar suas decis?es finais, que enfatizam a relev?ncia do capital social para melhorar os resultados do sistema de cr?dito. Portanto, embora tenha o car?ter de ineditismo, este trabalho pode pavimentar os futuros trabalhos sobre este assunto importante e pol?mico, considerando a certeza da influ?ncia do capital social em cr?ditos banc?rios, otimizando e proporcionando um aumento de todo o sistema financeiro.

Made available in DSpace on 2015-04-14T14:27:00Z (GMT). No. of bitstreams: 1 438881.pdf: 3090442 bytes, checksum: e1afa5b812d3a913bc077dad1885a315 (MD5) Previous issue date: 2012-03-29 / The present study aimed to examine the existence and relevance of the credit channel, the channel being divided between bank lending and balance sheet channel, the transmission of monetary policy in Brazil from January 2001 to July 2011, for this was used IPCA and IGP-DI. The methodology analyzes the Vector Auto-Regressive (VAR), as Granger causality tests, impulse function and response, variance decomposition analysis and speeds, and this, coming from the test Vector Error Correction (VECM .) The results show the credit channel, bank loans in the segment, important and relevant to raise economic growth, but with greater significance using the IGP-DI, and sustainable over time and an auxiliary channel to channel the money. Since the channel of the balance sheet, despite showing that increases the production of the economy, a channel is negligible, but significant, even if a channel has little development, and most influential currency, securities and exchange. Can not correspond to say that an auxiliary channel of the coin. And that use of the IPCA collaborates with the results of the IGP-DI increasing the production of the Brazilian economy to its potential level. The research concludes that there is in the Brazilian economy during this period, the four transmission channels of monetary policy. / O presente estudo teve como objetivo examinar a exist?ncia e a relev?ncia do canal de cr?dito, sendo dividido entre o canal dos empr?stimos banc?rios e o canal do balan?o patrimonial, na transmiss?o da pol?tica monet?ria no Brasil no per?odo de janeiro de 2001 a julho de 2011, para isso foi usado o IGP-DI e o IPCA. A metodologia utilizada foi as an?lises de Vetores Auto-Regressivo (VAR), como os testes de causalidade de Granger, fun??o impulso e resposta, decomposi??o da vari?ncia e an?lise das velocidades, sendo este, oriundo do teste de Vetor de Corre??o de Erros (VECM). Os resultados encontrados mostram o canal de cr?dito, no segmento empr?stimos banc?rio, importante e relevante para elevar o crescimento econ?mico, mas com maior signific?ncia com o uso do IGP-DI, sendo sustent?vel ao longo prazo e um canal auxiliar ao canal da moeda. J? o canal do balan?o patrimonial, apesar de mostrar que eleva a produ??o da economia, ? um canal pouco significativo, mas relevante, mesmo sendo um canal ainda pouco desenvolvimento, sendo mais influente a moeda, os t?tulos e o c?mbio. N?o podendo dizer que correspondem a um canal auxiliar ao da moeda. E que o uso do IPCA colabora com os resultados do IGP-DI elevando a produ??o da economia brasileira ao seu n?vel potencial. A pesquisa conclui que existem na economia brasileira, neste per?odo, os quatro canais de transmiss?o da pol?tica monet?ria.

Made available in DSpace on 2015-12-03T18:32:55Z (GMT). No. of bitstreams: 1 Rogerio_Vecchi_Cestari.pdf: 759725 bytes, checksum: 23dc0ded94c11d56a473ec63b511e1fc (MD5) Previous issue date: 2005-06-07 / This research identifies the relations between the variables behavior's profile, working performance and perception of factors that constitute the motivational strategy used by the researched institution. In order to achieve the proposed goals, 119 retail banking account managers has been researched. This way, by means of the performance background from this officials in the fulfillment of goals the institution established, behavior performance identification based on the work developed by Ricco (2004) and the evaluation of the perception of factors that the referred motivational strategy consists of through a questionnaire prepared by the researcher, it was possible to establish the proposed relations. The theoretical foundation that mainly supported this research is found in the works of Robbins (2002), DuBrin (2003), Fromm (1989), Coda (2000) and Ricco (2004). The datum analysis allowed identifying that, according to the motivational strategy used by the institution, there's a difference between the performance presented by the different behavior profiles, as has been noted, when comparing it with the other profiles, the conquering profile presents a better performance whereas the collaborator and expert profiles present lower performances. From the relation between the performance at work and the individuals perception before the factors constituting the referred motivational strategy, it can be seen that the individual with a lower performance highly care about service quality and group work, although this aren't prior factors in this motivational strategy. As a result, analyzing the relation between the behavior profiles and the individuals' perception before the factors that constitute the motivational strategy in question, it hasn't been noticed a statistically meaningful importance of a certain factor to the detriment of other factors, that is, statistically no factor has prevailed to another. However, even without a statistically significant difference among the factors, the importance given to them is different for each behavior's profile. / Esta pesquisa identifica as rela????es entre as vari??veis perfil comportamental, desempenho no trabalho e percep????o dos fatores que comp??em a estrat??gia motivacional utilizada pela institui????o pesquisada. Para atingir os objetivos propostos, foram pesquisados 119 gerentes de conta de um banco de varejo. Assim, por meio do hist??rico de desempenho destes funcion??rios no cumprimento das metas estabelecidas pela institui????o, da identifica????o do perfil comportamental com base no trabalho desenvolvido por Ricco (2004) e da avalia????o da percep????o dos fatores que comp??em a referida estrat??gia motivacional por interm??dio de question??rio elaborado pelo pesquisador, foi poss??vel estabelecer as rela????es propostas. O embasamento te??rico que predominantemente sustentou esta pesquisa encontra-se nas obras de Robbins (2002), DuBrin (2003), Fromm (1986), Coda (2000) e Ricco (2004). A an??lise dos dados permitiu identificar que, diante da estrat??gia motivacional utilizada pela institui????o, existe diferen??a entre o desempenho apresentado pelos diferentes perfis comportamentais, sendo que, quando comparado aos demais perfis, o perfil conquistador apresenta melhor desempenho enquanto os perfis colaborador e especialista apresentam piores desempenhos. Da rela????o entre o desempenho no trabalho e a percep????o dos indiv??duos perante os fatores que comp??em a referida estrat??gia motivacional, observa-se que os indiv??duos com baixo desempenho d??o mais import??ncia ?? qualidade do atendimento e ao trabalho em grupo, n??o sendo estes fatores priorit??rios nesta estrat??gia motivacional. Por fim, analisando-se a rela????o entre os perfis comportamentais e a percep????o dos indiv??duos perante os fatores que comp??em a estrat??gia motivacional em quest??o, para todos os perfis comportamentais n??o foi percebida a import??ncia estatisticamente significativa de determinado fator em detrimento a outro, ou seja, estatisticamente nenhum fator se sobressaiu a outro. Por??m, mesmo sem haver diferen??a estatisticamente significativa entre os fatores, a import??ncia atribu??da a eles ?? diferente para cada perfil comportamental.

Submitted by Elba Lopes (elba.lopes@fecap.br) on 2016-08-09T18:05:23Z No. of bitstreams: 2 H??lio Moreira J??nior.pdf: 1884251 bytes, checksum: 87bf1a3a50e49dfec01453507355ca9c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-09T18:05:24Z (GMT). No. of bitstreams: 2 H??lio Moreira J??nior.pdf: 1884251 bytes, checksum: 87bf1a3a50e49dfec01453507355ca9c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-06-27 / After monetary stabilization seen in Brazil in the mid-1990s, there was a significant increase in partnerships formed between financial institutions and retailers in order to offer financial products and services. On one hand, these partnerships offer significant advantages for both parties, such as new sales channels, increase of customer base, funding for credit operations, new means of payment to leverage sales and increase the financial return. Moreover, such partnerships generate conflicts of credit, strategies, management and costs. This paper aims to identify and analyze the main conflicts between Financial Institutions and Retailers in managing partnerships aimed at the marketing of financial products and services. To accomplish this goal, I conducted 18 semi-structured interviews with executives who work in institutions from this market, 6 of them being retail executives and 12 executives from financial institutions. The results indicated that the most relevant conflicts are associated with credit, governance, technological solution, service, cost allocation and primary goals of these partnerships. / Ap??s a estabiliza????o monet??ria verificada no Brasil em meados da d??cada de 1990, houve um aumento significativo de parcerias formadas entre Institui????es Financeiras e Varejistas com o objetivo de ofertar produtos e servi??os financeiros. Por um lado, essas parcerias oferecem vantagens significativas para ambos os atores, tais como novos canais de vendas, aumento da base de clientes, funding para a opera????o de cr??dito, novo meio de pagamento para alavancagem das vendas e aumento do retorno financeiro. Por outro lado, tais parcerias geram conflitos de cr??dito, de estrat??gias, de gest??o e de custos. Neste trabalho o objetivo ?? identificar e analisar os principais conflitos entre Institui????es Financeiras e Varejistas na gest??o de parcerias que visam ?? comercializa????o de produtos e servi??os financeiros. Para cumprir esse objetivo foram realizadas 18 entrevistas semiestruturadas com executivos que atuam em institui????es desse mercado, sendo 6 delas com executivos do varejo e 12 com executivos de institui????es financeiras. Os resultados indicaram que os conflitos mais relevantes est??o associados com cr??dito, governan??a, solu????o tecnol??gica, atendimento, aloca????o de custos e objetivos prim??rios destas parcerias.

La réfrigération magnétique est une technologie émergente grâce à des avantages considérables par rapport aux technologies de réfrigération classiques. Cette technologie basée sur l’effet magnétocalorique offre d’importants avantages environnementaux car d’une part l’efficacité théorique des cycles utilisés est supérieure à celle des technologies classiques et d’autre part son fonctionnement ne nécessite pas une utilisation de gaz/vapeur `a fort effet de serre. En revanche des verrous scientifiques restent à lever, Le modèle multi-physique proposé dans cette thèse à pour but d’améliorer la précision de calcul. Il consiste à coupler un modèle 3D magnétostatique résolu par la méthode des éléments finis, un modèle magnétocalorique analytique et un modèle thermo-fluidique résolu par méthode des différences finies. Parallèlement, un banc d’essais a été conçu, optimisé et réalisé, ce banc permettra de faire des mesures fines des différents phénomènes qui interagissent dans la réfrigération magnétique. / The magnetic refrigeration technology is a promising alternative technology to the production of cold. The work of this thesis deals with studying and designing a magnetic refrigeration prototype. A multiphysic model is developed, this model taking into account several magnetic and magnetocaloric aspect that never dealt in the literature. It is used to investigate the influence of a range of parameters on the performance of the AMR. A new test bench of magnetic refrigeration is also designed, it is based on a particular electromagnet that was optimally realized. The magnetic performances are showed and concord with design prevision. Finally, suggestions for future works are provided based on the knowledge presented here.

Made available in DSpace on 2016-04-28T20:19:10Z (GMT). No. of bitstreams: 1 2007-Ludimila Hanna Arbach.pdf: 1443768 bytes, checksum: 0c436bd66da3f8c03c866ce31a488dad (MD5) Previous issue date: 2007-08-15 / The theoretical support for this research is concentrated upon the competence based management principles. Its objective overall is to identify the employees and clients perceptions regarding the individual competencies developed, acquired and applied by the bank workers during their daily routine. A revision survey of the literature for the concept of competence is presented as well as a historical report about the banking institutions and the evolution of the activities of their employees. Two banking agencies in the city of Resende RJ have been analyzed, one public and the other one private, aiming at the comparison of the perceptions among the bank workers and with that of their clients afterwards. As a means to data collection a questionnaire to be responded by the bank workers and the clients was applied. The results showed to be positive for the bank workers perception of their individual competencies. However, the clients perception for the public bank was showed to be otherwise but the clients perception for the private was showed the same. / A fundamenta??o te?rica desta pesquisa concentra-se nas proposi??es da gest?o baseada em compet?ncias. O objetivo geral deste trabalho ? identificar a percep??o declarada dos funcion?rios e dos clientes do setor banc?rio, em rela??o ?s compet?ncias individuais desenvolvidas, adquiridas e aplicadas pelos banc?rios na sua rotina de trabalho. Faz-se uma revis?o bibliogr?fica sobre o conceito de compet?ncia, um hist?rico sobre as institui??es banc?rias e a evolu??o das atividades exercidas pelos profissionais que trabalham nessas organiza??es. A pesquisa analisou duas ag?ncias banc?rias da cidade de Resende - RJ, sendo uma do setor p?blico e outra do setor privado, visando ? compara??o da percep??o entre os pr?prios banc?rios e posterior compara??o com a percep??o dos clientes destas ag?ncias. A pesquisa indicou resultado positivo para a percep??o dos banc?rios sobre suas compet?ncias individuais entre as ag?ncias estudadas. Entretanto a percep??o dos clientes da institui??o banc?ria p?blica diverge da opini?o dos seus respectivos funcion?rios, enquanto a percep??o dos clientes da ag?ncia privada apresenta similaridades.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-17T14:20:44Z No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-17T14:20:57Z (GMT) No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) / Made available in DSpace on 2017-04-17T14:20:57Z (GMT). No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) Previous issue date: 2016-06-01 / Banking credit plays a key role for the economic development and, therefore, it is important to understand its dynamics and its actuation for the transmission of the monetary policy. Thus, this thesis consists of two studies that aim to understand the micro and macroeconomic behavior of bank credit, investigating the main determinants of bank credit as well as the interaction of the banking sector with other sectors of the economy. The microeconomic analysis aims to identify the major determinants of banking credit in the Brazilian economy, considering the influence of specific characteristics of the financial institutions and monetary policy in the period 2001 to 2012. This paper contributes with the literature by showing that there was no relevant impact from the macroeconomic environment on the credit supply in the analyzed period. The government has adopted a countercyclical credit policy mismatched from prevailing macroeconomic conditions. In turn, the macroeconomic analysis investigates the effects of credit risk for the financial intermediation and how this risk is transmitted to other agents in the economy. The DSGE model with financial frictions of Gertler and Karadi (2011) was modified to incorporate the risk of default given by the probability of non-payment of loans granted by the bank. This study contributes to the literature by deriving the probability of default of firms endogenously in the model, unlike most of the studies that assume it as exogenous. Moreover, as the model assumes two different interest rates for the two kinds of borrowers ("good" and "bad" payers), it allows the analysis of the impacts of the borrowers??? quality on the overall interest rate on loans. As a result, we identified a countercyclical default rate, which compensates the bank for the lost with ???bad??? payers. / O cr??dito banc??rio possui um papel fundamental para o desenvolvimento econ??mico de um pa??s e, por isso, ?? muito importante compreender sua din??mica e sua atua????o na transmiss??o da pol??tica monet??ria. Por essa raz??o, esta tese ?? formada por dois estudos que visam entender o comportamento do cr??dito banc??rio de forma micro e macroecon??mica, investigando os principais aspectos que o determinam, bem como a intera????o do setor banc??rio com os demais setores da economia. A an??lise microecon??mica buscou identificar empiricamente os determinantes do cr??dito banc??rio no Brasil, sob a ??tica da oferta, de modo a averiguar o efeito das estrat??gias dos bancos e evidenciar o impacto da pol??tica monet??ria sobre a oferta de cr??dito no per??odo de 2001 a 2012. Esse estudo constatou que n??o houve impacto do ambiente econ??mico sobre a oferta de cr??dito no per??odo analisado, dado que o governo adotou uma pol??tica credit??cia antic??clica descasada das condi????es macroecon??micas vigentes. Por outro lado, a an??lise macroecon??mica buscou investigar os efeitos do risco de cr??dito na intermedia????o financeira e como esses efeitos s??o repassados aos demais agentes da economia. Para tanto, utilizou-se o modelo DSGE com fric????es financeiras de Gertler e Karadi (2011), que foi modificado de modo a incorporar o risco de default dado pela probabilidade de n??o pagamento dos empr??stimos concedidos pelo banco. Esse estudo contribui com a literatura ao derivar a probabilidade de default das firmas endogenamente ao modelo, diferente de grande parte dos artigos que a tratam como uma medida ex??gena. Ademais, ao trazer duas taxas de juros distintas para diferentes tomadores de cr??dito, os ???bons??? e os ???maus??? pagadores, o modelo permite a an??lise de como a qualidade dos mutu??rios impacta na taxa de juros global dos empr??stimos. Como resultado, encontra-se uma taxa de default antic??clica, que funciona como uma compensa????o para o banco pelas perdas com os ???maus??? pagadores.

Le travail présenté dans ce manuscrit a pour objet l’étude et le développement d’un banc de caractérisation généraliste appliqué à l’extraction du modèle comportemental d’amplificateur TPM-NIM (Two-Path Memory Nonlinear Integral). Ce modèle qui dispose d’une des architectures les plus abouties au laboratoire XLIM requiert une instrumentation microonde haut de gamme, très onéreuse, hors de portée de la majorité des concepteurs pour sa mise en œuvre expérimentale. L’objectif est donc de proposer des principes de mesure originaux permettant d’identifier le modèle TPM-NIM avec une instrumentation standard. Dans ces travaux, deux bancs sont présentés : tout d’abord, un banc de caractérisation développé autour d’une instrumentation de pointe disposant des meilleures propriétés pour extraire le modèle. Puis, un banc construit autour d’une instrumentation standard mais incluant des méthodes de traitement et de mesure novatrices. Ces deux bancs ont été utilisés avec plusieurs véhicules de tests et il ressort que le second permet de diminuer le bruit des mesures de phase tout en réduisant le coût total des équipements. Enfin, une dernière partie est consacrée à la comparaison du modèle TPM-NIM avec deux modèles comportementaux classiques mettant en avant sa polyvalence. / The work presented in this manuscript is devoted to the study and development of a general characterization bench applied to the extraction of the TPM-NIM (Two-Path Memory Nonlinear Integral) amplifier behavioral model. This model, has one of the most advanced architectures at the XLIM laboratory. It requires a high-end microwave instrumentation, overpriced and beyond reach for most of the designers for its experimental implementation. The aim is to propose some original measurements principles allowing the TPM-NIM model’s identification with a standard instrumentation. Two benches are presented in these works : firstly, a characterization bench, developed using a high performance instrumentation with the best properties to extract the model. Then, a bench, built with a standard instrumentation but through innovative processing and measurement methods. These two benches have been used with several test vehicles and it appears that the second one decreases the noise of phase measurements while reducing the equipment’s total cost. Finally, a last part is dedicated to the comparison of the TPM-NIM model with two classic behavioral models by emphasizing its versatility.

Les rivières présentent généralement un lit ondulé dû à la présence de bancs, qui correspondent à des larges dépôts sédimentaires alternant avec des zones profondes (mouilles). Des travaux d'ingénierie importants et répétés modifiant la géométrie du cours d'eau, le régime hydraulique et l'apport sédimentaire peuvent à terme modifier la dynamique des bancs à l'échelle de la rivière. Une meilleure compréhension des processus liés aux bancs est importante pour les gestionnaires des rivières, car les bancs contrôlent activement la morphologie du lit et érodent les berges, impactant la navigation, les prises d'eaux, les ouvrages et la qualité des habitats. Même si les mécanismes régissant la formation et le développement des bancs sont bien compris, la compréhension de la morphodynamique des bancs en milieu fluvial reste limitée, en raison de la non-linéarité induite par la combinaison de facteurs naturels en atrophiques. La non-uniformité des sédiments est une caractéristique inhérente des rivières, mais son impact sur la propriété des bancs, même dans des cas simplifiés, reste obscure. Ce travail de thèse vise à étudier l'impact de l'hétérogénéité granulométrique sur des bancs dans des chenaux endigués, via l'utilisation d'un modèle morphodynamique bi-dimensionnel implémenté dans le système Telemac-Mascaret. Les développements numériques nécessaires sont apportés afin d'être en accord avec l'état de l'art sur la modélisation de bancs avec un sédiment-non-uniforme. Par la suite, ce modèle est utilisé pour l'étude de la morphodynamique des bancs dans un chenal rectiligne sur la base d'expériences réalisées en laboratoire. Finalement, l'analyse est transférée sur un tronçon de 1 km de la Loire, caractérisé par sa géométrie relativement complexe. Les résultats permettent de valider l'approche de modélisation et démontrent la portabilité pour d'autres études, apportent plus d'éléments sur la relation entre sédiment non-uniforme et les bancs, et pourront être utilisés pour préconiser les gestionnaires des rivières / Rivers often present a wavy bed topography due to the presence of bars, corresponding to large sediment deposits alternating with deeper areas (pools). Intense and continual river engineering works altering the river geometry, flow regime and sediment supply can impact bar morphodynamics at the reach scale. A deep knowledge of bar processes is important for river managers, because bars actively control the river bed topography and influence bank erosion, with consequences for navigation, water intakes, infrastructure and the quality of their habitats. Although the origin of bar formation and propagation is well understood, the understanding of bar morphodynamics in rivers remains limited due to the non-linearity of combined natural and anthropogenic effects. Sediment non-uniformity is an inherent characteristic of rivers, but its impact on bar properties, even considering simple configurations, is still unclear. This Ph.D. thesis aims at investigating the impact of sediment size heterogeneity on bars in rivers with non-erodible banks, using a two-dimensional morphodynamic model implemented in the Telemac-Mascaret system. The necessary model developments are brought to comply with the state of the art on the modelling of heterogeneous sediment with bars. Then, the model is used to study bar morphodynamics in a straight channel on the basis of laboratory experiments. Eventually, the analysis is transferred in a 1 km reach of the Loire river characterized by a relatively complex geometry. General outcomes validate the modelling approach and demonstrate the application portability for other study cases, shed more light on the relationship between non-uniform sediment and bars, and can be later used as recommendations for river managers.