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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Three Arias From Mozart’s Don Giovanni: a Comparative Analysis of Performance Issues and Technical Problems Found in Four Complete Piano-Vocal Scores. A Vocal Accompanist’s Perspective

Fateeva, Anna A 01 May 2011 (has links)
The objective of this essay is to study technical problems and performance issues in the piano-reduction accompaniments of three solo arias from Mozart’s Don Giovanni: “Or sai chi l’onore,” “Dalla sua pace la mia dipende,” and “Batti, batti, o bel Masetto.” This study is executed through the comparative analysis of the arias’ accompaniments from four piano-vocal score editions of the opera (Bärenreiter, G. Schirmer, Ricordi, and Boosey & Hawkes) with cross-reference to the full orchestral score (the Neue Mozart-Ausgabe). The essay contains a detailed presentation of the merits and flaws of each of the four piano-vocal score editions; a discussion of the realizations’ quality; examples by the author of plausible modifications; and the author’s suggestions for practice, fingering, pedaling, and dealing with various performance issues. This essay can provide a stimulus for vocal pianists to explore the countless possibilities in piano realizations of the orchestral accompaniments of operatic works, and to continue to refine and improve their ability to imitate orchestral sonorities and textures at the piano.
22

Catalytic Asymmetric Ketone and Alkene Reductions Using Transition Metal Complexes

Källström, Klas January 2006 (has links)
This thesis contains seven papers dealing with iridium and ruthenium based catalytic asymmetric reductions, either of ketones into chiral alcohols, or olefins into chiral alkanes. The first part of the thesis describes how we have designed and evaluated new bicyclic ligands containing either N,S or N,N chelating atoms. The ligands have been evaluated in the asymmetric Ir-catalyzed transfer hydrogenation of acetophenone. The complexes evaluated induced good enentioselectivity of the product. Moreover we have also utilized a commercially available chiral diamine (QCD-amine) as a ligand in the Ru-catalyzed hydrogenation of prochiral ketones, with excellent enantioselectivity for some of the substrates used. As part of this work we investigated, both theoretically and experimentally, the mechanism of this hydrogenation. Based on these results we have proposed a new reaction mechanism for this type of hydrogenations which involves active participation of the solvent in the catalytic cycle. The last part of the thesis describes the design, synthesis and evaluation of N,P and N2C-carbene,N ligands for the Ir-catalyzed hydrogenation of carbon-carbon double bonds. The selectivities obtained in these investigations are among the best reported so far for a broad variation of substrates. A selectivity model for this hydrogenation has been derived and used in the rationalization of the results. As a part of this work we have synthesized and evaluated a new class of substrates, vinyl silanes, and showed that the scope of the hydrogenation reaction can be expanded to this new substrate class.
23

Reductions and Triangularizations of Sets of Matrices

Davidson, Colin January 2006 (has links)
Families of operators that are triangularizable must necessarily satisfy a number of spectral mapping properties. These necessary conditions are often sufficient as well. This thesis investigates such properties in finite dimensional and infinite dimensional Banach spaces. In addition, we investigate whether approximate spectral mapping conditions (being "close" in some sense) is similarly a sufficient condition.
24

Reductions and Triangularizations of Sets of Matrices

Davidson, Colin January 2006 (has links)
Families of operators that are triangularizable must necessarily satisfy a number of spectral mapping properties. These necessary conditions are often sufficient as well. This thesis investigates such properties in finite dimensional and infinite dimensional Banach spaces. In addition, we investigate whether approximate spectral mapping conditions (being "close" in some sense) is similarly a sufficient condition.
25

Integrability of Second-Order Partial Differential Equations and the Geometry of GL(2)-Structures

Smith, Abraham David January 2009 (has links)
<p>A GL(2,R)-structure on a smooth manifold of dimension n+1 corresponds to a distribution of non-degenerate rational normal cones over the manifold. Such a structure is called k-integrable if there exist many foliations by submanifolds of dimension k whose tangent spaces are spanned by vectors in the cones.</p><p>This structure was first studied by Bryant for n=3 and k=2. The work included here (n=4 and k=2,3) was suggested by Ferapontov, et al., who showed that the cases (n=4,k=2) and (n=4, k=3) can arise from integrability of second-order PDEs via hydrodynamic reductions.</p><p>Cartan--Kahler analysis for n=4 and k=3 leads to a complete classification of local structures into 54 equivalence classes determined by the value of an essential 9-dimensional representation of torsion for the GL(2,R)-structure. These classes are described by the factorization root-types of real binary octic polynomials. Each of these classes must arise from a PDE, but the PDEs remain to be identified. </p><p>Also, we study the local problem for n >= 5 and k=2,3 and conjecture that similar classifications exist for these cases; however, the interesting integrability results are essentially unique to degree 4. The approach is that of moving frames, using Cartan's method of equivalence, the Cartan--Kahler theorem, and Cartan's structure theorem.</p> / Dissertation
26

Analysis and interpretation of astrophysical optical emission-line spectra / Susan Ilani Loubser

Loubser, Susan Ilani January 2005 (has links)
This study consists of a quantitative optical emission-line analysis of spectra from five blue compact galaxies (Zw 0855, Mrk 1267, II Zw 33, Tol 2 & Tol 3), as well as a qualitative analysis of spectra from two galactic H II regions (NGC 3603 & NGC 3576). It serves a two-fold purpose: first, to understand the CCD reduction, spectra extraction and different nebular analysis methods, together with their applications and limitations, preparatory to studies using the Southern African Large Telescope (SALT) and second, to extend current star formation related research to include extragalactic starburst galaxies. The observations were carried out using the 1.9m telescope (equipped with a grating spectroscope and CCD detector) of the South African Astronomical Observatory (SAAO), during the period 1 to 7 March 2005. The necessary CCD data reduction, spectra extraction, wavelength and flux calibration, Doppler shift as well as reddening correction procedures were performed before the emission lines were identified and measured. A full nebular analysis, including temperature, density, metallicity (oxygen abundance) and other chemical abundance determinations, was performed on the blue compact galaxies (BCGs). Two different nebular analysis packages viz. IRAF's nebular and SNAPwere used, with all the results well within the range of values expected for metal poor BCGs. Recommendations on the different methods and their applications are made. / Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2006.
27

Methods for reducing vehicular greenhouse gas emissions using electric vehicles and wind-electricity

Kannan, Shanmuga Sundaram 12 July 2012 (has links)
Recently, electric vehicles (EVs) have been gaining attention in passenger transportation due to their greater fuel economy and reduced greenhouse gas (GHG) emissions compared to conventional vehicles (CVs). The amount of GHG emissions reduction from EVs depends on the energy sources used to generate electricity. Wind is a clean, renewable energy source and EVs charged from wind-generated electricity do not produce any emissions. However, wind is variable in nature. This thesis examines the potential impact of EVs on reducing a jurisdiction’s vehicular GHG emissions using locally available wind-electricity. Four methods of charging EVs using wind-electricity are considered, with grid-electricity as a backup, and the overall well-to-wheels GHG emission reductions are discussed. The thesis includes a case study of Summerside. The results show that up to 68% of the EVs’ demands were met with wind-electricity, and Summerside’s vehicular GHG emissions were reduced by between 56% and 73% when compared to CVs.
28

Analysis and interpretation of astrophysical optical emission-line spectra / Susan Ilani Loubser

Loubser, Susan Ilani January 2005 (has links)
This study consists of a quantitative optical emission-line analysis of spectra from five blue compact galaxies (Zw 0855, Mrk 1267, II Zw 33, Tol 2 & Tol 3), as well as a qualitative analysis of spectra from two galactic H II regions (NGC 3603 & NGC 3576). It serves a two-fold purpose: first, to understand the CCD reduction, spectra extraction and different nebular analysis methods, together with their applications and limitations, preparatory to studies using the Southern African Large Telescope (SALT) and second, to extend current star formation related research to include extragalactic starburst galaxies. The observations were carried out using the 1.9m telescope (equipped with a grating spectroscope and CCD detector) of the South African Astronomical Observatory (SAAO), during the period 1 to 7 March 2005. The necessary CCD data reduction, spectra extraction, wavelength and flux calibration, Doppler shift as well as reddening correction procedures were performed before the emission lines were identified and measured. A full nebular analysis, including temperature, density, metallicity (oxygen abundance) and other chemical abundance determinations, was performed on the blue compact galaxies (BCGs). Two different nebular analysis packages viz. IRAF's nebular and SNAPwere used, with all the results well within the range of values expected for metal poor BCGs. Recommendations on the different methods and their applications are made. / Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2006.
29

As mulheres indígenas nos relatos jesuíticos da província do Paraguai (1609-1768)

Mendes, Isackson Luiz Cavilha January 2013 (has links)
Na Província Jesuítica do Paraguai, entre os anos de 1609 e 1768, os jesuítas fundaram as reduções de índios com o objetivo de civilizar e converter ao cristianismo os gentios. Nesse processo de redução houve a necessidade de deslocar as mulheres de suas atividades tradicionais. A partir das prescrições de gênero ocidentais foram conferidos às mulheres indígenas espaços restritos de atuação com a finalidade de diminuir o seu prestígio junto aos grupos ameríndios. Apesar da tentativa dos padres de impor uma rotina, circunscrevendo as mulheres ao espaço doméstico e/ou de confinamento, houve apropriações e resistências a este ordenamento sugerido. O trânsito intenso das mulheres, na construção criativa dos espaços de sociabilidade, faz delas agentes de mediação muito além do papel idealizado pelos jesuítas, restrito à maternidade e ao lar. Neste trabalho analiso o protagonismo feminino a partir dos relatos jesuíticos evidenciando um cotidiano mais matizado do que as narrativas inacianas supõem. / In the Jesuit Province of Paraguay, between the years 1609 and 1768, the Jesuits founded the reductions of Indians in order to civilize and convert the heathen to Christianity. This reduction process was necessary to move women from their traditional activities. From the Western genre prescriptions were granted to indigenous women restricted spaces of operation in order to reduce its prestige among the Amerindian groups. Despite the attempts of priests to impose a routine circumscribing women's domestic and / or confinement of space, resistance and appropriation was suggested this order. The heavy traffic of women in the creative construction of spaces of sociability makes them agents of mediation beyond the role envisioned by the Jesuits, confined to motherhood and home. In this paper I analyze the female protagonist from the Jesuit reports showing a more nuanced everyday narratives assume that the Ignatian.
30

Treewidth : algorithmic, combinatorial, and practical aspects / Treewidth : aspects algorithmiques, combinatoires et pratiques

Baste, Julien 22 September 2017 (has links)
Dans cette thèse, nous étudions la complexité paramétrée de problèmes combinatoires dans les graphes. Plus précisément, nous présentons une multitude d’algorithmes de programmation dynamique ainsi que des réductions montrant que certains de ces algorithmes sont optimaux. Nous nous intéressons principalement à la treewidth, un paramètre de graphes pouvant être vu comme une mesure de distance entre la structure d’un graphe et la structure topologique d’un arbre. Certains de nos algorithmes sont aussi paramétrés par la taille de la solution demandée et le degré maximum du graphe donné en entrée. Nous avons obtenu un certain nombre de résultats dont certains d’entre eux sont listés ci-dessous. Nous présentons un encadrement du nombre de graphes étiquetés de treewidth bornée. Nous étendons le domaine d’application de la théorie de la bidimensionalité par contraction au delà des graphes ne contenant pas de graphe apex en tant que mineur. Nous montrons aussi que la technique des structures de Catalan, outil améliorant l’efficacité des algorithmes résolvant des problèmes de connexité lorsque le graphe d’entrée est creux, ne peut être appliquée à la totalité des problèmes de connectivité, même si l’on ne considère, parmi les graphes creux, que les graphes planaires. Nous considérons le problème F-M-Deletion qui, étant donné une collection de graphes F, un graphe G et un entier k, demande s’il est possible de retirer au plus k sommets de G de telle sorte que le graphe restant ne contienne aucun graphe de F en tant que mineur. Nous considérons aussi la version topologique de ce problème, à savoir F-TM-Deletion. Ces deux problèmes généralisent des problèmes de modification de graphes bien connus tels que Vertex Cover, Feedback Vertex Set et Vertex Planarization. En fonction de la collection de graphes F, nous utilisons différentes techniques de programmation dynamique pour résoudre F-M-Deletion et F-TM-Deletion paramétrés par la treewidth. Nous utilisons des techniques standards, la structure des graphes frontières et l’approche basée sur le rang. En dernier lieu, nous appliquons ces techniques algorithmiques à deux problèmes issus du réseau de communications, à savoir une variation du problème classique de domination et un problème consistant à trouver un arbre couvrant possédant certaines propriétés, et un problème issu de la bioinformatique consistant à construire un arbre contenant en tant que mineur (topologique) un ensemble d’arbres donnés correspondant à des relations d’évolution entre ensembles d’espèces. / In this thesis, we study the Parameterized Complexity of combinatorial problems on graphs. More precisely, we present a multitude of dynamic programming algorithms together with reductions showing optimality for some of them. We mostly deal with the graph parameter of treewidth, which can be seen as a measure of how close a graph is to the topological structure of a tree. We also parameterize some of our algorithms by two other parameters, namely the size of a requested solution and the maximum degree of the input graph. We obtain a number of results, some of which are listed in the following. We estimate the number of labeled graphs of bounded treewidth. We extend the horizon of applicability of the theory of contraction Bidimensionality further than apex-minor free graphs, leading to a wider applicability of the design of subexponential dynamic programming algorithms. We show that the Catalan structure technique, that is a tool used to improve algorithm efficiency for connectivity problems where the input graph is restricted to be sparse, cannot be applied to all planar connectivity problems. We consider the F-M-Deletion problem that, given a set of graphs F, a graph G, and an integer k, asks if we can remove at most k vertices from G such that the remaining graph does not contain any graph of F as a minor. We also consider the topological version of this problem, namely F-TM-Deletion. Both problems generalize some well-known vertex deletion problems, namely Vertex Cover, Feedback Vertex Set, and Vertex Planarization. Depending on the set F, we use distinct dynamic programming techniques to solve F-M-Deletion and F-TM-Deletion when parameterized by treewidth. Namely, we use standard techniques, the rank based approach, and the framework of boundaried graphs. Finally, we apply these techniques to two problems originating from Networks, namely a variation of the classical dominating set problem and a problem that consists in finding a spanning tree with specific properties, and to a problem from Bioinformatics, namely that of construcing a tree that contains as a minor (or topological minor) a set of given trees corresponding to the evolutionary relationships between sets of species.

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