Orientador: Jose Roberto Zan / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-08-14T17:30:30Z (GMT). No. of bitstreams: 1 Pinto_JoaoPaulodoAmaral_M.pdf: 6828945 bytes, checksum: b0e6967a207bca86632cf629ed108239 (MD5) Previous issue date: 2008 / Resumo: Esse trabalho é resultado de uma pesquisa sobre a obra musical do músico e compositor Tião Carreiro (José Dias Nunes, 1934-1993). O enfoque principal foi identificar os elementos constitutivos e as características do estilo desse artista como instrumentista de viola, instrumento reconhecido como o símbolo da chamada música caipira. Para tanto, foram analisados musicalmente os dois LPs instrumentais do violeiro gravados em 1976 e 1979. Além disso, foram abordados os aspetos históricos da viola caipira, do segmento instrumental sertanejo e da trajetória do artista no mercado fonográfico. A partir das análises musicais, foi identificado um conjunto de elementos e técnicas utilizados pelo músico para construir seus toques e solos. A pesquisa também relacionou e caracterizou musicalmente as matrizes e gêneros, caipiras ou não, utilizados pelo violeiro na gravação desses dois discos. Entre eles, destaca-se o pagode de viola, gênero criado no final dos anos cinqüenta a partir da combinação de algumas matrizes musicais e que, por ter se tornado a marca principal do violeiro, foi objeto de uma investigação mais aprofundada. / Abstract: This work is the result of a research on the musical work of the musician and composer Tião Carreiro (José Dias Nunes, 1934-1993). The main focus was to identify the constituent elements and the characteristics of the style of this artist as a viola (Brazilian ten-string guitar) instrumentalist, considering the viola a recognized instrument as the symbol of what is so called música caipira (typical rural music of the central-southern region of Brazil). For that, the two first instrumental LPS of the artist, recorded in 1976 and 1979, were musically analysed. Besides that, historical aspects of viola caipira, also from the instrumental sertanejo segment and the trajectory of the artist in the phonographic market were approached. From these musical analyses a group of elements and techniques used by the musician to build his touches and solos was identified. The research also related and musically characterized the origins and genders, caipira or not, used by the violeiro in the recordings of these two records. Among them, there is one in particular, the pagode de viola, gender created at the end of the fifties's, from the combination of some musical origins and that, for having become the main mark of the violeiro, was the subject of a deepened investigation. / Mestrado / Mestre em Música

Made available in DSpace on 2014-07-29T14:49:10Z (GMT). No. of bitstreams: 1 Dissertacao Mavine Pereira Barbosa Monteiro.pdf: 1704398 bytes, checksum: 3e8f45ec1c515688e890585ce8b2b04b (MD5) Previous issue date: 2011-03-29 / This thesis assumes that the externalities caused by lack of information about the safety of our food are caused mostly by lack of information, which characterizes a market failure, in which the latter cannot coordinate integration between the various players in this market, as producers and consumers, exporters and importers, what economists call the information asymmetry. Lack of information increases transaction costs, since consumers do not have access to perfect information about the products they consume, with damage costs will have to investigate the origin of the food they are buying. This theory also applies to the costs of informational asymmetry that producers face, since they also need to know about the origin and quality of inputs they use in production, so that the product certification and seed emerges as a solution to the problem of information asymmetry. According to the theoretical framework of New Institutional Economics, contracts assist in the reduction of transaction costs in the operation of an economy, and the informational asymmetry is one of these transaction costs, which causes a market failure. For this study we analyzed the possible certification as an inhibitor of such asymmetric information, since this is also a contract that the producers of some good firm with a public or private institution with a commitment to meet pre-established norms and that the information on the origin, quality, validity and other important features are exposed in the certification seal of the product, inspiring confidence for potential buyers of the product and possibly raising the value-added product. For this study examined the case of a possible certification of geographical indication for the bean seeds produced by an association of producers in the floodplains of river Javaés, arm of the Araguaia River, in the municipality of Lagoa Confusion in the state of Tocantins, where he addressed the potential economic benefits for producers and local economy of the region and the sustainability and environmental impacts that the intensive cultivation in tropical wetlands can cause to the ecosystem of that region. / Esta dissertação parte do pressuposto de que as externalidades causadas pela falta de informação sobre a segurança dos alimentos são causadas, na maioria das vezes, por falta de informações, o que caracteriza uma falha de mercado, na qual este último não consegue coordenar a integração entre os diversos atores neste mercado, como os produtores e consumidores, exportadores e importadores, o que os economistas denominam de assimetria informacional. A falta de informação faz aumentar os custos de transação, visto que o consumidor não tendo acesso à informação perfeita sobre os produtos que consomem, terão prejuízos com custos na investigação da origem do alimento que estão comprando. Essa teoria também se aplica aos custos da assimetria informacional que os produtores estão sujeitos, pois estes também precisam saber sobre a origem e qualidade dos insumos que utilizam na produção, desta forma a certificação dos produtos e sementes surge como solução para o problema da assimetria informacional. Segundo o arcabouço teórico da Nova Economia Institucional, os contratos auxiliam na redução de custos de transações presentes no funcionamento de uma economia, e a assimetria informacional constitui um desses custos de transação, o que causa uma falha de mercado. Para este trabalho analisamos a certificação como uma possível inibidora dessas informações assimétricas, já que também se trata de um contrato que os produtores de certo bem firmam com uma instituição pública ou privada com o compromisso de cumprir normas preestabelecidas e que as informações sobre a origem, qualidade, validade e outras características importantes estarão expostas no selo de certificação do produto, inspirando confiança para os potenciais compradores do produto e possivelmente elevando o valor agregado do produto. Para este estudo foi analisado o caso de uma possível certificação por Indicação Geográfica para as sementes de feijão produzidas por uma associação de produtores nas várzeas do rio Javaés, braço do rio Araguaia, no município Lagoa da Confusão no estado do Tocantins, onde se abordou os possíveis benefícios econômicos para os produtores e economia local da região e a sustentabilidade e impactos ambientais que o cultivo intensivo em várzeas tropicais pode provocar para o ecossistema daquela região.

Cláudio Santoro (1919-1989) compôs, ao todo, quatorze sinfonias ao longo de toda a sua vida. A Primeira Sinfonia para duas orquestras de cordas (1940), além de possuir uma formação instrumental curiosa, também representa uma das obras inaugurais de sua primeira etapa como compositor, procurando ao lado de Koellreutter, novos paradigmas para a composição musical de seu tempo, tendo influenciado uma geração de compositores brasileiros. Este trabalho pretendeu desenvolver uma atenta e inédita análise da Primeira Sinfonia de Cláudio Santoro, procurando demonstrar sobre qual estética atonal, sendo ela dodecafônica ou livre, a obra foi escrita. Além da identificação sugerida, propõe-se também a averiguação de possíveis hibridismos estéticos que podem ter ocorrido na Primeira Sinfonia de Santoro. A análise atenta dos movimentos que constituem essa obra, utilizando métodos como a Teoria dos Conjuntos desenvolvido por Allen Forte, a Teoria dos Contornos Musicais de Robert Morris e a relação parcimoniosa entre diferentes coleções tal como proposto por Dmitri Tymoczko, nos permitiu identificar alguns processos pós-tonais, que indicam influencias de autores como Claude Debussy, Paul Hindemith e Heitor Villa-Lobos no primeiro movimento Allegro Majestoso da Primeira Sinfonia de Santoro. A manutenção de algumas sonoridades como a coleção pentatônica, a escala de tons inteiros e a coleção acústica, são alguns dos indícios que nos permite identificar tais influencias na obra de Santoro. No segundo movimento Andante quasi adagio, podemos observar um processo serial tradicional, que se desenvolveu a partir de duas séries que se relacionam. Tal apontamento foi possível a partir do método da identificação e contagem serial, tal como proposto por autores como Kostka e Francolí. No terceiro movimento, observamos uma estrutura que é engendrada a partir de coleções simétricas como a coleção eneatônica e a escala octatônica paradigmática, além de outras formatações simétricas que ocorrem a partir de sobreposições entre camadas, procedimento que também é encontrado na obra de Villa-Lobos. Nesse sentido, a Primeira Sinfonia para duas orquestras de cordas de Cláudio Santoro, foi engendrada através de procedimentos pós tonais considerados livres e sistêmicos, sendo possível observar hibridismos estilísticos nesta obra. / Cláudio Santoro (1919-1989) composed, in all, fourteen symphonies throughout his life. The First Symphony for two stringed orchestras (1940), in addition to possessing a curious instrumental formation, also represents one of the inaugural works of his first stage as composer, looking alongside Koellreutter, new paradigms for the musical composition of his time, having influenced a generation of Brazilian composers. This work developed a complete, attentive and unpublished analysis of the First Symphony of Claudio Santoro, trying to demonstrate on which atonal aesthetic, being it dodecaphonic or free, had written the work in question. Besides the suggested identification, it is also proposed the investigation of possible aesthetic hybridity that may have occurred in the First Symphony of Santoro. The careful analysis of the movements that constitute this work, using methods such as the Theory of Sets developed by Allen Forte, Robert Morris\'s Theory of Musical Constraints and the parsimonious relation between different collections as proposed by Dmitri Tymoczko allowed us to identify some post Which indicate influences by authors like Claude Debussy, Paul Hindemith and Heitor Villa-Lobos in the first Allegro Majestic movement of the First Symphony of Santoro. The maintenance of some sonorities such as the pentatonic collection, the whole-tone scale and the acoustic collection are some of the indications that allowed us to identify such influences in Santoro\'s work. In the second Andante quasi adagio movement, we can observe a traditional serial process, which developed from two series that relate, such an approach was possible from the method of serial identification and counting, as proposed by authors such as Kostka and Francolí. In the third movement, we observe a structure that is generated from symmetrical collections such as the eneatonic collection and the paradigmatic octatonic scale, as well as other symmetrical formations that occur from overlaps between layers, a procedure that is also found in the work of Villa-Lobos. In this sense, the First Symphony for two chord orchestras by Claudio Santoro was conceived through postural procedures considered free and systemic, being possible to observe stylistic hybrids in this work.

As attention on the music of Mieczysław Weinberg (1919-1996) has increased in the years after his death, so has the need for an analytical study of his musical style and language. This thesis surveys Weinberg’s changing style through a genre that spans almost his entire output: the string quartet. His close friendship and artistic affinity with Shostakovich helps make his music accessible to a wider audience, though closer examination reveals Weinberg’s individuality and a quite distinct language from that of his mentor. In support of this contention, a wide range of analytical approaches is deployed in this dissertation, along with a pragmatic methodology for presenting a holistic overview of Weinberg’s quartets. Weinberg’s quartet cycle occupies an important place in twentieth-century music, with parallels to Shostakovich, Bartók, and other Soviet composers, including Myaskovsky, Shebalin, Levitin, and Boris Chaykovsky; correspondences and distinctiveness are explored in the second chapter. The third chapter surveys Weinberg’s musical narratives, with recourse to theories from Kofi Agawu, Boris Asafiev, and Jacques Derrida. Form is the focus of the fourth chapter, where ideas from Mark Aranovsky, and James Hepokoski and Warren Darcy are deployed to highlight Weinberg’s problematising of traditional forms in his music. Chapter five explores Weinberg’s multi-faceted approach to harmony, with concepts expanded from Lev Mazel, Yury Kholopov, and the neo-Riemannian school of analysis. The picture that emerges is of Weinberg’s individuality and distinctive voice, manifested in a controlled experimentalism and a tendency towards extended lyricism. His affinity with better-known composers may prove an approachable entry-point for wider audiences, but many of the most striking elements in his quartet cycle are of his own invention. His quartets stand as an important contextual dimension for understanding Shostakovich’s cycle, and also for appreciating the broader repertoire of Soviet chamber music. As his centenary approaches, engagement with Weinberg’s music continues to increase: this thesis provides contexts and analysis-based conclusions to complement this ongoing revival.

The gauge/string correspondence provides a non-perturbative definition of string theory and hence quantum gravity in some backgrounds, making it possible to translate statements about strongly coupled quantum field theories into results about gravity. <p><p>In this thesis, we focus on the derivation of holographic backgrounds from the field theory, without using any supergravity input. Instead, we rely crucially on the addition of probe D-branes to the stack of D-branes generating the background.<p>From the field theory description of the probe branes in the presence of the background branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the D-brane probe action in a generic supergravity background then allows to determine the holographic background dual to the considered field theory vacuum.<p><p>In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons.<p><p>The second part contains the original results of this thesis, obtained by applying this strategy to several specific examples. We first derive the duals to three continuous deformations (Coulomb branch, β and non-commutative deformations) of the basic case, in the limit in which the D-instantons can probe the full geometry. We then derive the enhançon mechanism in a dual to a simple N=2 quiver gauge theory by using a fractional D-instanton as a probe and exploiting recent exact results on the Coulomb branch of N=2 quivers.<p>Finally, we obtain the near-horizon D4-brane geometry by probing the D4-branes with a small number of D0-branes.<p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Les contacts entre une corde vibrante et un obstacle unilatéral interviennent dans de nombreux instruments de musique tels que la tampoura, le sitar ou encore la basse électrique. Ils introduisent une forte non-linéarité dans le mouvement de la corde, qui se traduit notamment par d'importants transferts d'énergie. Dans ce manuscrit, une étude à la fois numérique et expérimentale du contact corde/obstacle est proposée. Trois types de schémas conservatifs sont développés. Ils s'appuient sur une description modale de la corde, ce qui permet un ajustement des fréquences propres et amortissements pour chaque mode. De plus, deux modèles de contact et frottement sont considérés, l'un régularisant et l'autre non. Des comparaisons à la solution analytique dans le cas d'un obstacle ponctuel sont menées et permettent une première validation des modèles. Des protocoles expérimentaux sont ensuite mis en place pour l'étude d'une corde isolée en présence d'un obstacle ponctuel, puis dans le cas d'une corde installée sur une basse électrique, munie ou non de frettes. Une forte concordance des signaux expérimentaux et numériques est observée sur des temps longs, montrant la capacité des modèles à rendre compte des éléments principaux observés expérimentalement. Enfin, une étude paramétrique est conduite dans le cas d'une basse munie de frettes, montrant l'influence de paramètres tels que la position de pincement de la corde et le réglage des frettes sur le son produit. Ces ajustements sont directement liés à des problématiques récurrentes et centrales rencontrées par les musiciens et les luthiers. / Collisions between a vibrating string and a unilateral obstacle arise in a number of instruments such as tanpuras, sitars and electric basses. Contacts introduce a strong nonlinearity in the string motion, resulting in energy transfers. In this document, a numerical and experimental study of string/obstacle contacts is investigated. Three conservative numerical schemes are developed. They rely on a modal description of the string, so that a fine tuning of eigenfrequencies and damping parameters is possible for each mode. Moreover, contact and friction models are numerically treated either with a penalty approach or with a nonsmooth contact dynamics method. In the case of a point obstacle, comparisons to an analytical solution constitute a first validation of models. Experiments are then carried out in the case of an isolated string vibrating against a point obstacle, as well as in the case of a string vibrating against the neck of a fretted or fretless electric bass on which the string is installed. A good agreement is observed between numerical and experimental signals over long durations, showing the ability of models to take into account the essential physical features experimentally observed. Finally, a parametric study is led on a fretted electric bass, showing the influence of parameters such as the plucking position and the fretboard profile on the resulting sound. These adjustements are directly related to common and central issues met by guitar makers and players.

Les nombreux écrits théoriques d’Antoine Reicha sont bien connus de la musicologie, qui voit dans le théoricien un personnage central du XIXe siècle. Sa production musicale reste cependant encore largement ignorée. Ainsi, les 20 quatuors à cordes de Reicha édités de son vivant n’ont encore fait l’objet d’aucune étude approfondie : les 8 premiers sont publiés en 1804-1805 lors du séjour viennois de Reicha, les 12 suivants paraissent dans les années 1820, après son installation définitive à Paris. Leur publication entre deux grandes capitales de la musique s’étend des derniers quatuors de Haydn aux derniers quatuors de Beethoven : ces quatuors constituent donc un corpus d’étude privilégié pour la connaissance de l’œuvre musicale de Reicha, mais aussi pour celle du genre du quatuor à l’époque. Cette thèse s’appuie sur l’établissement d’une édition critique des quatuors de Reicha ; leur étude se poursuit par la mise au jour des présupposés esthétiques qui sous-tendent les écrits théoriques de Reicha et se clôt par l’analyse des phénomènes d’intertextualité entre ses quatuors et des œuvres de Haydn et Mozart ainsi que par l’observation de leur écriture à travers le prisme des écrits théoriques de la fin du XVIIIe siècle. L’étude proprement analytique révèle les constantes et les variantes stylistiques entre les « Quatuors viennois » du début du siècle et les « Quatuors parisiens » des années 1820. La comparaison systématique avec un large contre-corpus formé de quatuors contemporains permet de situer les quatuors de Reicha par rapport à l’héritage viennois revendiqué, mais aussi par rapport aux musiciens français actifs sous la Restauration. / Anton Reicha’s numerous theoretical writings are well-known in musicology today. Though Reicha is seen as a central theorist of the 19th century, his proper music nevertheless remains largely unknown. This PhD dissertation studies Reicha’s twenty string quartets published during his lifetime – which up to now have not been investigated in depth. The first eight quartets were published in 1804-1805 during Reicha’s stay in Vienna, whereas the last twelve were published in the 1820’s, after the composer settled in Paris: that is, they were published during a period lasting from Haydn’s last quartets to Beethoven’s last quartets. As a consequence, these quartets represent a corpus of particular relevance of knowledge of Reicha’s musical work, as well as for the history of this genre in the 19th century. This PhD dissertation, based on both an aesthetic and an analytical approach, creates a critical edition of Reicha’s quartets. This study starts by shedding light on the aesthetic premises of Reicha’s theoretical work and then analyses intertextual phenomena between his quartets and some of Haydn’s and Mozart’s works. Eventually it examines the composition process of Reicha’s quartets in the light of late 18th-century theoretical writings. The study of the constants and the variations of style between the early 19th-century “Vienna quartets” and the 1820’s “Paris quartets” is at the core of this study. The systematic comparison between the Reicha’s corpus and a counter-corpus made of quartets by Haydn, Mozart, Beethoven, Onslow and Cherubini helps situating Reicha as regarding his claimed Vienna legacy, but also as regarding French musician from the “Restauration” era.

當今已有數以百萬計的行動應用程序在 Apple 的 App Store 中發布，並在iOS設備下載量超過150億次。為了保護iOS用戶免於惡意應用程式的傷害，Apple 對於上架之App 有相對嚴格的審查政策。通過審查的App才能在App Store中發布。在本文中，我們提出基於 iOS可執行檔的靜態字串分析技術用於檢驗App可能動態載入之類別 。為了檢查動態載入之類別是否符合Apple之規範，必須要能確定動態加載函數之可能字串參數值 。我們方法的第一步是使用現有工具擷取 iOS可執行檔的組合語言。然後自組合語言中建立整個程式的控制流程圖（CFGs） 。接著，在控制流程圖上識別動態加載類別的函數，並且對於該函數的每個參數，我們構造一個字串相依圖，用以顯示流向字串參數值的所有構成成分以及構成方式 。最後，我們對這些可能流向參數的字串進行字串分析，以確定這些參數值所有的可能值集合。透過把這些可能值與特徵值（從Apple 審查政策建構而來，例如私有/敏感性API），我們能夠檢測到App 潛在違背Apple政策之情形。我們分析了1300多種目前上架於App Store的App，並檢查他們是否違反蘋果關於使用私有API的政策以及 廣告識別碼（IDFA）政策。我們的工具提取了超過37000 這些App的字符相依圖，分析結果顯示208個App透過字串操作構組合出對應的API名稱並且有潛在的IDFA違規濫用之可能。我們的分析還發現了372個可以使用字串構建私有類名稱的應用程序和236個可以使用路徑字符串加載私有框架的App，這些App可能違反Apple 禁止使用私有API使用政策。 / Millions of mobile apps have been published in Apple's AppStore with more than 15 billion downloads by iOS devices. In order to protect iOS users from malicious apps, Apple has strict policies which are used to eliminate apps before they can be published in the AppStore. In this paper we present a string analysis technique for iOS executables for statically checking policies that are related to dynamically loaded classes. In order to check that an app conforms to such a policy, it is necessary to determine the possible string values for the class name parameters of the functions that dynamically load classes. The first step of our approach is to construct the assembly for iOS executables using existing tools. We then extract flow information from the assembly code and construct control flow graphs (CFGs) of functions. We identify functions that dynamically load classes, and for each parameter that corresponds to a dynamically loaded class, we construct a dependency graph that shows the set of values that flow to that parameter. Finally, we conduct string analysis on these dependency graphs to determine all potential string values that these parameters can take, which identifies the set of dynamically loaded classes. Taking the intersection of these values with patterns that characterize Apple's app policies (such as private/sensitive APIs), we are able to detect potential policy violations. We analyzed more than 1300 popular apps from Apple's AppStore and checked them against Apple's policy about the use of private APIs and the identifier for Advertising (IDFA). Our tool extracted more than 37000 string dependency graphs from these applications and our analysis reported 208 apps that compose the corresponding API with strings and have potential IDFA violations. Our analysis also found 372 apps that could have compose the private class name with string and 236 apps that could have load the private framework with path string; and could violate the private API usage policy.

Le but de cette thèse est d'étudier lagravité quantique bidimensionnelle. Nousnous intéressons plus particulièrement auxapproches dans le continu. Ces dernièresreposent principalement sur l'action deLiouville qui décrit le couplage entre théorieconforme et gravité. Si cette action, bienconnue, est très bien comprise, la mesure del'intégrale fonctionnelle sur l'espace desmétriques pose plus de problèmes. Toutefois,sous l'hypothèse simplificatrice d'une mesurede champ libre, la dépendance en l'aire de lafonction de partition de la gravité quantiqueen présence de matière conforme a pu êtreétablie. Malgré l'hypothèse assez forte sur lamesure d'intégration, cette formule (diteKPZ), a été confirmée par des calculs issusde méthodes discrètes, et ce dans plusieurscas particuliers. Grâce à une nouvelle méthode derégularisation spectrale en espace courbe,cette mesure d'intégration a récemment puêtre proprement définie. Dans cette thèse,un calcul perturbatif de la fonction departition à aire fixée est mené, jusqu'à troisboucles, en considérant l'action de Liouvilleet des surfaces de Kähler de genrequelconque (qui coïncident avec l'ensembledes surfaces à deux dimensions). Desdivergences apparaissant dans les calculs, ilest nécessaire de renormaliser les actions.Cette renormalisation peut être interprétéecomme une renormalisation de la mesured'intégration. Nos résultats à deux bouclessont finis, indépendants de la régularisationet compatibles avec le résultat KPZ, maisdépendent d'un paramètre libre. L'étude àtrois boucles suggère que la théorie resterenormalisable aux ordres supérieurs maisdépend de nouveaux paramètres à chaqueordre. Ces résultats ont été généralisé dansle cas du tore au couplage à de la matièrenon-conforme. / Nowadays, two-dimensional quantumgravity can be studied in two differentapproaches, one involving discrete theories(triangulation, matrix model...), the othercontinuous ones, mainly based on the socalled Liouville action which universallydescribes the coupling of any conformal fieldtheory to gravity. While the Liouville action isrelatively well understood, the appropriatefunctional integral measure is however rathercomplicated. Nevertheless, a formula for thearea dependence of the quantum gravitypartition function in the presence of conformalmatter has been obtained, under thesimplifying assumption of a free-fieldmeasure. Notwithstanding its non-rigorousderivation, this formula, often referred to asthe KPZ formula, has since been verified inmany instances and has scored manysuccesses. Recent developments of efficient multiloopregularization methods on curved spacetimesopened the way for a precise and welldefinedperturbative computation of the fixedareapartition function in the Kählerformalism. In this work, a first-principlescomputation of the fixed-area partitionfunction in the Liouville theory is performed,up to three loops. Among other things, therole of the non-trivial quantum gravityintegration measure is highlighted.Renormalization is required and may beinterpreted as a renormalization of theintegration measure. This leads to a finite andregularization-independent result at two loops,that is more general than the KPZ result,although compatible. Finiteness andregularization-independence seem alsopossible at three loops. These results aregeneralized to the coupling to non-conformalmatter on the torus.

Nous étudions différents aspects liés aux compactifications hétérotiques avec torsion. Nous définissons et calculons le genre elliptique vêtu associé aux compactifications Fu-Yau, et exploitons ce résultat pour calculer les corrections de seuil à une boucle de différents couplages BPS-saturés dans l’action effective de supergravité à quatre dimen- sions. Enfin nous nous intéressons à des solutions supersymétriques non-compactes qui généralisent, entre autres, les solutions hétérotiques connues sur le conifold. / We study various aspects of heterotic compactifications with torsion. We de- fine and compute the dressed elliptic genus associated to Fu-Yau compactifications, and use this result to compute one-loop threshold corrections to various BPS-saturated cou- plings in the four-dimensional effective supergravity action. Finally, we study non-compact supersymmetric solutions which generalize, among others, the known heterotic solutions on the conifold.