Ensemblestück für Oboe, Klarinette, Fagott, Marimba, 2 Violinen, Viola, Violoncello und Kontrabass. Das in freier Tonalität gehaltene Werk orientiert sich an der Sonatensatzform. Aufführungsdauer: 8\''20\".

L’objectif de cette thèse est d’améliorer la compréhension de l’acoustique du piano dans le contexte de la synthèse sonore par modèles physiques. Le manuscrit est décomposé en trois parties principales, dont les deux premières ont pour but la compréhension de l'origine de la double polarisation de la corde de piano, tandis que la dernière se focalise sur l’identification de sources d’un piano complet.Dans la première partie, la non linéarité géométrique, intervenant lorsque les amplitudesde vibration sont grandes, est étudiée afin de comprendre si le couplage non linéaire peut transmettre de l'énergie à une polarisation non initialement excitée et mener ainsi au phénomène de double polarisation. Un développement en échelles multiples est mené sur un modèle de corde de Kirchhoff-Carrier avec les deux extrémités fixes, restreint au mode fondamental de chacune des polarisations. Les deux oscillateurs ont alors des fréquences très proches, on parle de résonance 1:1. La condition d’existence et le critère de stabilitépour l’apparition de double polarisation sont obtenus et validés numériquement sur la base des équations de Kirchhoff-Carrier, ainsi qu’avec un modèle de corde enrichi.Des expériences sont menées sur un dispositif monocorde où les angles de polarisation naturelle de la corde, le désaccord entre les deux polarisations et le comportement non linéaire son observés et identifiés.La seconde partie se concentre sur le couplage entre la corde et le chevalet. Les degrés de liberté de la corde sont couplés au chevalet dont les mouvements (translation/rotation) sont représentés par un ensemble d'oscillateurs. Les fréquences propres des différents systèmes couplés sont analysés. Des schémas numériques sont proposés et mis en {oe}uvre pour une résolution directe. Ces schémas résolvent les équations de corde par une méthode d’éléments finis d’ordre élevé et les équations du chevalet analytiquement. Les conditions de couplage entre corde et chevalet sont assurées par des multiplicateurs de Lagrange. Expérimentalement, la corde est tendue sur le chevalet dans une configuration de type zig-zag et excitée verticalement ou horizontalement. Dans les deux cas, les phénomènes de double polarisation et de double décroissance sont observés et des résultats qualitativement similaires sont obtenus avec les modèles numériques.La dernière partie s'attache à décrire quantitativement les différentes sources vibro-acoustiques d'un piano complet. Une étude est menée en utilisant une analyse des chemins de transfert (transfer path analysis en anglais) sur un piano Bösendorfer 280VC-9. Les contributions de la table d’harmonie, des parties interne et externe de la ceinture, du cadre en fonte et du couvercle sont étudiées dans le domaine fréquentiel. L’analyse montre que la table d’harmonie est le principal contributeur mais que le cadre en fonte et le couvercle jouent également un rôle significatif, en particulier à hautes fréquences. / The objective of this thesis is to improve the understanding of the acoustics of the piano in the context of physically-based sound synthesis. The manuscript is decomposed in three parts, the first two being devoted to the undertsanding of the origin of the double polarisation in piano string, while the third one is dedicated to the identification of sound sources of a complete piano.In the first part, the geometric (large-amplitude) nonlinearity is studied in order to understand if the nonlinear coupling can transfer energy to an initially non excited polarisation, thus leading to the double polarisation phenomenon. A multiple-scaleanalysis is conducted on a Kirchhoff-Carrier string model with fixed boundary conditions at both ends. Each polarisation is restrained to its fundamental mode, leading to two oscillors having nearly equal eigenfrequencies, and thus presenting a 1:1 internal resonance. The existence condition and stability criteria for double polarisation to occur are obtained and validated numerically based on the complete Kirchhoff-Carrier equations, as well as a more enriched third-order string model. Experiments are carried out on a monochord setup where the natural polarisation angles of the string, detuning between the two polarisations and its nonlinear behaviour are observed and identified.The second part is devoted to the string/bridge coupling. The degrees of freedom of the string are coupled to the bridge whose translational and rotational motions are respresented by a set of oscillators. The eigenfrequencies of various coupled systems are analysed. Numerical schemes are proposed and implemented where the string is solved via high-order finite-element method while the lumped bridge is solved analytically and coupled to the string by Lagrange multipliers. Experimentally, the string is strung over a bridge in a zig-zag configuration and excited vertically and horizontally. In both cases, double polarisation and double decay are observed and similar results are also obtained qualitatively in numerical models.The last part is devoted to a quantitative description of the vibroacoustic sources of a Bösendorfer 280VC-9 piano via operational transfer path analysis. The contribution of the soundboard, inner and outer rim, iron frame and lid are investigated in the frequency domain. It is found out that the soundboard is the primary contributor but the iron frame and the lid also play a significant role, especially at high frequencies.

This thesis is concerned with several problems in general relativity and low energy string theory that are pertinent to the time evolution of the gravitational field. We present a formulation of the Einstein field equations in terms of variational techniques borrowed from geometric analysis. These equations yield the evolution equations for the Cauchy problems of both general relativity and low energy string theory. We then proceed to investigate the evolutionary linear stability of Schwarzschild-like solutions in higher dimensional relativity called black strings. These objects are determined to be linearly unstable. This motivates a further stability analysis of the charged p-brane solutions of low energy string theory. We show that one can eliminate linear instabilities in p-branes for sufficiently large values of charge. We also consider the characteristic problem of general relativistic magnetohydrodynamics (GRMHD). We compute the eigenvalues and eigenvectors of GRMHD and establish degeneracy conditions. Finally, we consider the initial value problem for axisymmetric GRMHD. We formulate the general Einstein and MHD equations under the assumption of a stationary axisymmetric spacetime without assuming the circularity condition.

This thesis, titled ”Exploration in Art Music”, was conceived based on my curiosity to explore and compose music which combines the styles of jazz and Western classical music. Inspired by the Third Stream movement led by Gunther Schuller, which evolved in parallel with the 50’s avant-garde jazz scene, I have composed three musical pieces for a twelve-piece orchestra consisting of woodwinds, strings, and a jazz quartet. I’ve examined this work from the following two perspectives: As a composer – exploring ways to fuse the genres, observing contrasting idioms, and finding ways of opening up for improvisation when the music is otherwise through-composed. As a musician and bandleader – noticing how musicians from each of the two musical cultures approach and interpret written and improvised music. Throughout the project I have gotten a deeper insight into the culture of Western classical music, and this thesis observes and analyzes some of the differences and similarities, musically and performance-wise, between that and the jazz culture which I am originating from. / <p><strong>Framförd musik:</strong></p><p><em>Antmarch</em> - Erik Hasselfeldt</p><p><em>Midnatt i 1C307</em> - Erik Hasselfeldt</p><p><em>Akta dig för scootrar</em> - Erik Hasselfeldt</p><p><em>Louange á l’éternité de Jésus</em> - Olivier Messiaen</p><p><em>I stormens öga</em> - Erik Hasselfeldt</p><p><strong>Medverkande:</strong></p><p>Tvärflöjt – Tiitta Moilanen</p><p>Oboe – Sabina Scott</p><p>Bb Klarinett – Filippa Hedberg</p><p>Bb Klarinett &amp; basklarinett – Eskil Larsson</p><p>Fagott – Ciarán Hayes</p><p></p><p>Fiol – Maria Ikonen</p><p>Fiol – Vidar Karlsvärd</p><p>Cello – Elis Hakola</p><p></p><p>Sopran &amp; altsaxofon – Erik Hasselfeldt</p><p>Piano – Milos Lindegren</p><p>Kontrabas – Amanda Karström</p><p>Trummor – Filip Bällstav Öhman</p><p>Trumpet – Tumi Torfason</p>

In this thesis we employ string perturbation theory in toroidal orbifold models to study aspects of supersymmetry breaking in type IIB string theory. First, we determine the dependence of physical Yukawa couplings on blow-up moduli in models with D3-branes at orbifold singularities. Blow-up moduli are scalar fields describing the size of small blow-up cycles in the compactification geometry. In models implementing moduli stabilisation these fields can acquire F-terms and break supersymmetry. We examine the moduli-dependence of physical Yukawa couplings at string tree-level by computing disk correlation functions involving a Yukawa interaction of visible sector fields and an arbitrary number of blow-up moduli. We perform the calculation for one blow-up insertion explicitly and find that the correlation function vanishes if the blow-up modulus is associated with a small cycle distant to the visible sector. For more than one blow-up insertion we show that all such correlation functions are exponentially suppressed by the compactification volume. We explain how these results are relevant to suppressing soft terms to scales parametrically below the gravitino mass. Further, we determine corrections to holomorphic Yukawa couplings on D3-branes at an orbifold singularity due to non-perturbative effects such as gaugino condensation on a stack of D7-branes. This can be done by calculating a one-loop threshold correction to the gauge coupling on the D7-branes. We show that, if present, the new contributions to Yukawa couplings are not aligned with the tree-level couplings. As the new Yukawa couplings contribute to soft A-terms they are sources of flavour-changing neutral currents. Last we discuss an effect unrelated to supersymmetry breaking. We show that orbifold models with D3-branes at orbifold singularities can exhibit kinetic mixing of different massless Abelian factors. For this to be possible, the relevant U(1) factors have to be associated with more than one orbifold singularity.

L'adoption récente et généralisée des systèmes d'automatisation des véhicules, avec l’incorporation de la connectivité entre voitures, a encouragé l’utilisation des techniques comme le Contrôle Croisière Adaptatif Coopératif (CACC) et la conduite en convoi. Ces techniques ont prouvé l’amélioration du flux de trafic et la sécurité de la conduite, tout en réduisant la consommation d’énergie et les émissions CO_2. Néanmoins, la robustesse et la stabilité stricte du convoi, malgré les délais de communication et l’hétérogénéité des convois, restent des sujets de recherche en cours. Cette thèse a pour sujet la conception, l’analyse et validation de systèmes de contrôle pour le car-following automatisé et coopératif, en ciblant l’augmentation de ses avantages et son usage, en se concentrant sur la robustesse et la stabilité du convoi même sur des séries de véhicules hétérogènes avec des retards de communication. Une structure feedforward/feedback est développée, dont sa modularité est fondamentale pour la mise au point des approches avec des objectifs différents mais complémentaires. L’architecture permet non seulement l’adoption d’une stratégie d’espacement pour la range entière de vitesse, mais elle peut aussi être employée dans le cadre d’un CACC basé sur une machine d’état pour la conduite en convoi sur des environnements urbains avec des capacités de freinage d’urgence et de rejoint du convoi. Des différents algorithmes pour la conception de systèmes de contrôle feedback pour la régulation des distances sont présentés, pour quoi le calcul d’ordre fractionnaire démontre fournir des réponses fréquentielles de boucle fermé plus précises et satisfaire des besoins plus exigeantes. La performance est assurée malgré l’hétérogénéité avec la proposition de deux approches feedforward différents. Le premier est basé sur une topologie en considérant que le véhicule précédent dans la boucle, tandis que le deuxième inclut le véhicule leader pour améliorer la performance de suivi. Les algorithmes proposés sont validés avec des études de stabilité dans le domaine du temps et fréquence, ainsi que simulations et expérimentations réelles. / Recent widespread adoption of vehicle automation and introduction of vehicle-to-vehicle connectivity has opened the doors for techniques as Cooperative Adaptive Cruise Control (CACC) and platooning, showing promising results in terms of traffic capacity and safety improvement, while reducing fuel consumption and CO_2 emissions. However, robustness and strict string stability, despite communication delays and string heterogeneity is still an on-going research field. This thesis deals with the design, study and validation of control systems for cooperative automated car-following, with the purpose of extending their benefits and encourage their employment, focusing on robustness and string stability, despite possible V2V communication delays and string heterogeneity. A feedforward/feedback hierarchical control structure is developed, which modularity is fundamental for the proposal of approaches that target different but complementary performance objectives. The architecture not only permits the adoption of a full speed range spacing policy that target multiple criteria, but can also be employed in a state machine-based CACC framework for urban environments with emergency braking and platoon re-joining capabilities in case of pedestrian interaction. Different feedback control design algorithms are presented for the gap-regulation, for which the fractional-order calculus is demonstrated to provide more accurate closed loop frequency responses and satisfy more demanding requirements. Desired performance is ensured in spite of string heterogeneity through the proposal of two feedforward methods : one based on predecessor-only topology, while the second includes the leader vehicle information on feedforward to gain tracking capabilities. Proposed control algorithms are validated through time and frequency-domain stability studies, simulation and real platforms experiments.

Orientador: Gisela Gomes Pupo Nogueira / Banca: Giacomo Bartoloni / Banca: Sydney Molina Jr. / Resumo: Esta pesquisa constitui um estudo crítico de transcrições para violão do repertório para instrumentos de cordas dedilhadas, particularmente vihuelas, guitarras e alaúdes dos séc. XVI ao XVIII. Objetivando a proposição de subsídios teóricos para a elaboração da interpretação desse repertório, este trabalho discute os sistemas de codificação, os procedimentos de transcrição e a execução musical do repertório em questão, por meio do diálogo entre as Práticas Interpretativas e a Musicologia Histórica, assumindo como vertentes metodológicas o estudo dos sistemas de codificação, a crítica textual e a análise interpretativa de gravações. / Abstract: This research is a critical study of transcriptions for the guitar repertoire for plucked string instruments, particularly vihuela, guitars and lutes of the century. XVI to XVIII. Aiming to propose theoretical basis for the elaboration of the interpretation of this repertoire, this paper discusses the coding systems, procedures transcription and musical performance of the repertoire in question through dialogue between the practices and Historical Musicology and Interpretation Practices, assuming as methodological approaches the study of coding systems, textual criticism and the interpretative analysis of recordings. / Mestre

Esta pesquisa investiga as possibilidades de iniciação aos instrumentos de cordas dedilhadas por meio da improvisação livre. Ela divide-se em três partes: fundamentação teórica, oficinas de improvisação livre e elaboração de um caderno de iniciação. A reflexão teórica tem como principais referências, as pesquisas de Rogério L. M. Costa e H. J. Koellreutter a cerca da Improvisação Livre, e as investigações de Flávia M. Cruvinel sobre o Ensino Coletivo de Instrumentos Musicais. Os diversos tipos de gestos musicais são descritos com enfoque no gesto instrumental, termo adotado na pesquisa para representar os elementos da técnica instrumental. Os gestos instrumentais foram selecionados através de seis oficinas de improvisação livre realizadas nos Conservatórios Estaduais de Música do Triângulo Mineiro, onde se procurou uma forma de registro gráfico musical que favorecesse a prática da improvisação livre e colaborasse no desenvolvimento de um caderno de iniciação aos instrumentos de cordas dedilhadas. Esta nova proposta de iniciação instrumental divide-se em seis partes através da sugestão de roteiros para improvisação livre, grafados de forma não tradicional, com o objetivo de estimular a exploração sonora e timbrística em sintonia com a música da contemporaneidade. Através da criação, da liberdade gestual e da expansão da escuta, permite ao aprendiz desenvolver habilidades instrumentais e musicais para a criação de seu próprio repertório, de acordo com sua identidade, sua biografia, sua experiência de vida. / This research investigates the possibilities of initiation to plucked strings instruments through free improvisation. It is divided into three parts: theoretical foundation, free improvisation workshops and notebook initiation. The theoretical reflection has as main references the research of Rogério L. M. Costa and H. J. Koellreutter about Free Improvisation and Flávia M. Cruvinel investigations on Collective Teaching of Musical Instruments. The various kinds of musical gestures are described focusing on instrumental gesture, term adopted in the research to represent the elements of instrumental technique. The instrumental gestures were selected during six free improvisation workshops held in music conservatories in the state of Minas Gerais, where he sought a form of musical graphic record favoring the practice of free improvisation and collaborate into the development of a notebook initiation to plucked strings instruments. This new instrumental initiation proposal is divided into six parts that suggest a guide for free improvisation, written in a nontraditional way, with the aim of stimulating sound and timbre exploration combined with the contemporary music. Through the creation of the gestural freedom and the expansion of listening abilities, it seems likely that could develop musical and instrumental skills to create his/her own repertoire, according to his identity, his biography and life experience.

Esta pesquisa investiga as possibilidades de iniciação aos instrumentos de cordas dedilhadas por meio da improvisação livre. Ela divide-se em três partes: fundamentação teórica, oficinas de improvisação livre e elaboração de um caderno de iniciação. A reflexão teórica tem como principais referências, as pesquisas de Rogério L. M. Costa e H. J. Koellreutter a cerca da Improvisação Livre, e as investigações de Flávia M. Cruvinel sobre o Ensino Coletivo de Instrumentos Musicais. Os diversos tipos de gestos musicais são descritos com enfoque no gesto instrumental, termo adotado na pesquisa para representar os elementos da técnica instrumental. Os gestos instrumentais foram selecionados através de seis oficinas de improvisação livre realizadas nos Conservatórios Estaduais de Música do Triângulo Mineiro, onde se procurou uma forma de registro gráfico musical que favorecesse a prática da improvisação livre e colaborasse no desenvolvimento de um caderno de iniciação aos instrumentos de cordas dedilhadas. Esta nova proposta de iniciação instrumental divide-se em seis partes através da sugestão de roteiros para improvisação livre, grafados de forma não tradicional, com o objetivo de estimular a exploração sonora e timbrística em sintonia com a música da contemporaneidade. Através da criação, da liberdade gestual e da expansão da escuta, permite ao aprendiz desenvolver habilidades instrumentais e musicais para a criação de seu próprio repertório, de acordo com sua identidade, sua biografia, sua experiência de vida. / This research investigates the possibilities of initiation to plucked strings instruments through free improvisation. It is divided into three parts: theoretical foundation, free improvisation workshops and notebook initiation. The theoretical reflection has as main references the research of Rogério L. M. Costa and H. J. Koellreutter about Free Improvisation and Flávia M. Cruvinel investigations on Collective Teaching of Musical Instruments. The various kinds of musical gestures are described focusing on instrumental gesture, term adopted in the research to represent the elements of instrumental technique. The instrumental gestures were selected during six free improvisation workshops held in music conservatories in the state of Minas Gerais, where he sought a form of musical graphic record favoring the practice of free improvisation and collaborate into the development of a notebook initiation to plucked strings instruments. This new instrumental initiation proposal is divided into six parts that suggest a guide for free improvisation, written in a nontraditional way, with the aim of stimulating sound and timbre exploration combined with the contemporary music. Through the creation of the gestural freedom and the expansion of listening abilities, it seems likely that could develop musical and instrumental skills to create his/her own repertoire, according to his identity, his biography and life experience.

<p>In this thesis, two aspects of string theory are discussed, tensionless strings and supersymmetric sigma models.</p><p>The equivalent to a massless particle in string theory is a tensionless string. Even almost 30 years after it was first mentioned, it is still quite poorly understood. We discuss how tensionless strings give rise to exact solutions to supergravity and solve closed tensionless string theory in the ten dimensional maximally supersymmetric plane wave background, a contraction of AdS(5)xS(5) where tensionless strings are of great interest due to their proposed relation to higher spin gauge theory via the AdS/CFT correspondence.</p><p>For a sigma model, the amount of supersymmetry on its worldsheet restricts the geometry of the target space. For N=(2,2) supersymmetry, for example, the target space has to be bi-hermitian. Recently, with generalized complex geometry, a new mathematical framework was developed that is especially suited to discuss the target space geometry of sigma models in a Hamiltonian formulation. Bi-hermitian geometry is so-called generalized Kähler geometry but the relation is involved. We discuss various amounts of supersymmetry in phase space and show that this relation can be established by considering the equivalence between the Hamilton and Lagrange formulation of the sigma model. In the study of generalized supersymmetric sigma models, we find objects that favor a geometrical interpretation beyond generalized complex geometry.</p>