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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.
31

Le Traitement lexicographique des noms propres du vocabulaire politique dans les dictionnaires généraux de langue française / Lexicographical Treatment of the Proper Nouns of the Political Vocabulary in French Language Dictionaries

Elchacar, Mireille 26 August 2011 (has links)
La tradition lexicographique de langue française opère, en théorie, une séparation stricte entre noms communs et noms propres. Or, dans les faits, cette séparation touche surtout les noms propres de lieux et de personnes. En effet, l'observation des articles du vocabulaire politique révèle un nombre important de noms propres d'une autre nature dans les pages de dictionnaires, comme des noms propres d'institutions, de partis politiques ou d'événements et de périodes historiques. Qui plus est, ces noms propres reçoivent souvent un traitement lexicographique comparable à celui des noms communs. Toutefois, ce traitement n'a pas encore fait l'objet d'une étude approfondie, et on constate une lacune dans la métalexicographie à son sujet.Afin de faire la lumière sur le traitement lexicographique des noms propres du vocabulaire politique, nous avons procédé à une analyse de ces noms propres à travers quatre dictionnaires généraux de langue française (Le Nouveau Petit Robert 2007 (version électronique), Le Petit Larousse Illustré 2007 (version électronique), le Dictionnaire du français Plus – À l'intention des francophones d'Amérique (1988) et le Dictionnaire québécois d'aujourd'hui (1992). Nous avons d'abord mis sur pied une typologie des noms propres du vocabulaire politique susceptibles d'être définis dans les dictionnaires généraux de langue française; puis nous avons relevé ces noms propres dans les dictionnaires à l'étude. Il ressort de ce relevé que le nombre de noms propres du vocabulaire politique dans les dictionnaires est assez élevé pour nécessiter une caractérisation de la pratique lexicographique des entourant. En outre, la description du vocabulaire politique passe par une description des noms propres en plus des mots du lexique commun. Nous nous sommes penchée sur la manière dont sont présentés les noms propres dans les dictionnaires, pour conclure que leur intégration et leur identification n'obéit pas à une méthode systématique. Nous avons réfléchi à la nomenclature des noms propres à inclure dans le dictionnaire de langue à travers l'exemple des noms de partis politiques, dont ceux qui sont représentés dans les instances officielles devraient être décrits dans les dictionnaires généraux. Nous avons ensuite analysé en profondeur les catégories de noms propres les plus représentées dans notre corpus d'articles du vocabulaire politique (les noms propres d'événements et de périodes historiques, les noms de partis politiques, dont les sigles, et les noms propres d'institutions). À la suite de cette analyse, nous proposons une liste d'éléments que le traitement lexicographique devrait inclure afin de permettre une circonscription efficace du référent (en d'autres termes, les traits distinctifs que devrait contenir une définition suffisante pour ces type de noms propres). Un point commun à toutes les catégories concerne la prise en compte de la variation géographique : en contexte francophone particulièrement, le lieu doit être précisé par le traitement lexicographique. L'étude se termine par une analyse de l'arrimage entre noms propres et lexique commun dans les dictionnaires où ils sont intégrés dans même ouvrage (PLI) ou dans une même nomenclature (Dictionnaire Hachette, Dixel). Nous arrivons à la conclusion que ces particularités dictionnairiques ne remplacent pas une réflexion en profondeur sur l'intégration des noms propres du vocabulaire politique dans le dictionnaire de langue. / In theory, French lexicographical tradition separates the description of proper nouns from that of the other words. In reality, this separation concerns mostly proper names of persons and of places. The observation of the articles of the political lexicon reveals an important number of proper nouns of another nature, such as proper nouns of institutions, political parties, or historical events or periods. Not only are these proper nouns present in the general dictionaries, but they are often described in the same manner as the other words.In order to understand this phenomenon, we analyzed the proper nouns of the political vocabulary in four French language dictionaries: (Le Nouveau Petit Robert 2007 (version électronique), Le Petit Larousse Illustré 2007 (version électronique), le Dictionnaire du français Plus – À l'intention des francophones d'Amérique (1988) et le Dictionnaire québécois d'aujourd'hui (1992). We first developed a typology of the proper nouns in the political lexicon that were likely to receive a lexicographical treatment; we then looked for these proper nouns in the chosen dictionaries. What came out of this initial search was that there are enough proper names of the political vocabulary in French language dictionaries to study their lexicographical treatment. We also concluded that the description of the political lexicon should embrace both proper nouns and common words. We then studied the manner in which proper nouns are visually presented in the dictionaries, and concluded that dictionaries do not seem to obey a strict methodology. The word list seems also incomplete, as we concluded about the proper names of political parties - those who are officially represented in official instances are often lacking. We then analyzed in detail three categories of our typology – historical events and periods, political parties and institutions – and for each category, we put forward a list of elements which are necessary to ensure a good definition for this type of vocabulary. A common element for all categories is the necessity to specify the geographical setting (country, state, etc.) of the reality to which the name refers – this is particularly important for the French language, which is spoken in many places around the world. Our thesis ends with a look at new dictionaries that offer a word list combining proper nouns and regular words (Dixel, Dictionnaire Hachette). We conclude that those technical features do not replace a profound analysis and reflexion on the integration of proper nouns in French language dictionaries.
32

Structure and Proper Orthogonal Decomposition in Simulations of Wall-Bounded Turbulent Shear Flows with Canonical Geometries

January 2012 (has links)
abstract: Structural features of canonical wall-bounded turbulent flows are described using several techniques, including proper orthogonal decomposition (POD). The canonical wall-bounded turbulent flows of channels, pipes, and flat-plate boundary layers include physics important to a wide variety of practical fluid flows with a minimum of geometric complications. Yet, significant questions remain for their turbulent motions' form, organization to compose very long motions, and relationship to vortical structures. POD extracts highly energetic structures from flow fields and is one tool to further understand the turbulence physics. A variety of direct numerical simulations provide velocity fields suitable for detailed analysis. Since POD modes require significant interpretation, this study begins with wall-normal, one-dimensional POD for a set of turbulent channel flows. Important features of the modes and their scaling are interpreted in light of flow physics, also leading to a method of synthesizing one-dimensional POD modes. Properties of a pipe flow simulation are then studied via several methods. The presence of very long streamwise motions is assessed using a number of statistical quantities, including energy spectra, which are compared to experiments. Further properties of energy spectra, including their relation to fictitious forces associated with mean Reynolds stress, are considered in depth. After reviewing salient features of turbulent structures previously observed in relevant experiments, structures in the pipe flow are examined in greater detail. A variety of methods reveal organization patterns of structures in instantaneous fields and their associated vortical structures. Properties of POD modes for a boundary layer flow are considered. Finally, very wide modes that occur when computing POD modes in all three canonical flows are compared. The results demonstrate that POD extracts structures relevant to characterizing wall-bounded turbulent flows. However, significant care is necessary in interpreting POD results, for which modes can be categorized according to their self-similarity. Additional analysis techniques reveal the organization of smaller motions in characteristic patterns to compose very long motions in pipe flows. The very large scale motions are observed to contribute large fractions of turbulent kinetic energy and Reynolds stress. The associated vortical structures possess characteristics of hairpins, but are commonly distorted from pristine hairpin geometries. / Dissertation/Thesis / Ph.D. Mechanical Engineering 2012
33

O Significado dos nomes PrÃprios / The Meaning of Proper Names

Valdetonio Pereira de Alencar 17 August 2007 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A dissertaÃÃo trata do problema dos nomes prÃprios Ela se divide em duas partes Na primeira as teorias de Frege Russell Searle e Kripke sÃo examinadas de forma analÃtica e crÃtica Na segunda trato de forma sistemÃtica meu tema Procurei introduzir uma descriÃÃo definida que possui o mesmo comportamento semÃntico dos respectivos nomes prÃprios mas mantendo os aspectos fundamentais da teoria de Kripke acerca dos nomes prÃprios / My work is divided in two parts First I explain the theories (about proper names) of Frege Russell Searle and Kripke Second my approach is more systematical I wanted to introduce a definite description that it has the same behavior semantic of the proper name (co-extensional with the definite description) However I pretended to maintain the fundamental aspects of the theory of Kripke about the proper names
34

The HST Large Programme on ω Centauri. II. Internal Kinematics

Bellini, Andrea, Libralato, Mattia, Bedin, Luigi R., Milone, Antonino P., Marel, Roeland P. van der, Anderson, Jay, Apai, Dániel, Burgasser, Adam J., Marino, Anna F., Rees, Jon M. 25 January 2018 (has links)
In this second installment of the series, we look at the internal kinematics of the multiple stellar populations of the globular cluster omega Centauri in one of the parallel Hubble Space Telescope (HST) fields, located at about 3.5 hal-flight radii from the center of the cluster. Thanks to the over 15 yr long baseline and the exquisite astrometric precision of the HST cameras, well-measured stars in our proper-motion catalog have errors as low as similar to 10 mu as yr(-1), and the catalog itself extends to near the hydrogen-burning limit of the cluster. We show that second-generation (2G) stars are significantly more radially anisotropic than first-generation (1G) stars. The latter are instead consistent with an isotropic velocity distribution. In addition, 1G stars have excess systemic rotation in the plane of the sky with respect to 2G stars. We show that the six populations below the main-sequence (MS) knee identified in our first paper are associated with the five main population groups recently isolated on the upper MS in the core of cluster. Furthermore, we find both 1G and 2G stars in the field to be far from being in energy equipartition, with eta(1G) = -0.007 +/- 0.026 for the former and eta(2G) = 0.074 +/- 0.029 for the latter, where eta is defined so that the velocity dispersion sigma(mu) scales with stellar mass as sigma(mu) proportional to m(-eta). The kinematical differences reported here can help constrain the formation mechanisms for the multiple stellar populations in omega Centauri and other globular clusters. We make our astro-photometric catalog publicly available.
35

PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING

Piatek, Slawomir, Pryor, Carlton, Olszewski, Edward W. 17 November 2016 (has links)
This article reports a measurement of the proper motion of Leo II, a dwarf galaxy that is a likely satellite of the Milky Way, based on imaging with the Hubble Space Telescope and Wide Field Camera. 3. The measurement uses compact background galaxies as standards of rest in both channels of the camera for two distinct pointings of the telescope, as well as a QSO in one channel for each pointing, resulting in the weighted average of six measurements. The measured proper motion in the the equatorial coordinate system is (mu(alpha), mu(delta))= (-6.9 +/- 3.7, -8.7 +/- 3.9) mas century(-1) and in the Galactic coordinate system it is (mu(l), mu(b)) = (6.2 +/- 3.9, -9.2 +/- 3.7) mas. century(-1). The implied space velocity with respect to the Galactic center is (Pi, Theta, Z) =(-37 +/- 38, 117 +/- 43, 40 +/- 16) km s(-1) or, expressed in Galactocentric radial and tangential components, (V-r, V-tan) = (21.9 +/- 1.5, 127 +/- 42) km s(-1). The space velocity implies that the instantaneous orbital inclination is 68 degrees, with a 95% confidence interval of (66 degrees, 80 degrees). The measured motion supports the hypothesis that Leo. II, Leo. IV, Leo. V, Crater. 2, and the globular cluster Crater fell into the Milky Way as a group.
36

Space Motions of the Dwarf Spheroidal Galaxies Draco and Sculptor Based on HST Proper Motions with a ∼10 yr Time Baseline

Sohn, Sangmo Tony, Patel, Ekta, Besla, Gurtina, van der Marel, Roeland P., Bullock, James S., Strigari, Louis E., van de Ven, Glenn, Walker, Matt G., Bellini, Andrea 06 November 2017 (has links)
We present new proper motion (PM) measurements of the dwarf spheroidal galaxies (dSphs) Draco and Sculptor using multiepoch images obtained with the Hubble Space Telescope ACS/WFC. Our PM results have uncertainties far lower than previous measurements, even those made with the same instrument. The PM results for Draco and Sculptor are (mu(W),mu(N))(Dra) = (-0.0562 +/- 0.0099, -0.1765 +/- 0.0100 mas yr(-1) and (mu(W), mu(N) )(Scl) = (-0.0296 +/- 0.0209, 0.1358 +/- 0.0214 mas yr(-1)) -1. The implied Galactocentric velocity vectors for Draco and Sculptor have radial and tangential components: (V-rad, V-tan)(Dra) =(-88.6, 161.4) +/- (4.4, 5.6) km s(-1) and (V-rad, V-tan )(Scl) = (72.6, 200.2)+/-(1.3, 10.8) km s(-1). We study the detailed orbital histories of both Draco and Sculptor via numerical orbit integrations. Orbital periods of Draco and Sculptor are found to be 1-2 Gyr and 2-5 Gyr, respectively, accounting for uncertainties in the Milky Way (MW) mass. We also study the influence of the Large Magellanic Cloud (LMC) on the orbits of Draco and Sculptor. Overall, the inclusion of the LMC increases the scatter in the orbital results. Based on our calculations, Draco shows a rather wide range of orbital parameters depending on the MW mass and inclusion/exclusion of the LMC, but Sculptor's orbit is very well constrained, with its most recent pericentric approach to the MW being 0.3-0.4 Gyr ago. Our new PMs imply that the orbital trajectories of both Draco and Sculptor are confined within the " Disk of Satellites," better so than implied by earlier PM measurements, and likely rule out the possibility that these two galaxies were accreted together as part of a tightly bound group.
37

Stratégie multiparamétrique pour la conception robuste en fatigue / Multiparametric strategy for robust design in fatigue

Relun, Nicolas 12 December 2011 (has links)
La conception robuste de pièce mécaniques consiste à prendre en compte dans la modélisation les sources d'incertitudes.Le modèle devient alors assez représentatif de la réalité pour pouvoir diminuer les marges de sécurité, qui permettent de garantir que la pièce en fonctionnement ne sera pas mise en défaut.Dans le cas de pièces aérospatiales, une diminution des marges de sécurité est un enjeu économique majeur car cela entraîne une diminution du poids des pièces.La probabilité de défaillance est une des quantités critiques lors de la conception robuste. Celle-ci quantifie le risque de défaillance de la pièce en comparant la probabilité de résistance du matériau (caractérisée à partir d'essais sur éprouvettes) avec la probabilité de sollicitation du matériau, qui est déterminée à partir des contraintes extérieures à la pièce et des caractéristiques du matériau. C'est ce dernier problème qui a fait l'objet de cette thèse.Dans le cas d'un comportement non linéaire du matériau, la détermination de la probabilité de sollicitation impose d'exécuter de nombreuses fois un calcul de la pièce pour différentes valeurs des conditions aux limites et des paramètres du comportement matériau.Ceci devient rapidement hors de portée sans une stratégie adaptée, un calcul pouvant prendre jusqu'à 12 heures.Une stratégie dédiée à la résolution de l'ensemble de ces calculs est proposée dans ce travail. Elle tire parti de la similarité des calculs pour diminuer le temps total nécessaire. Un gain allant jusqu'à 30 est atteint sur des pièces industrielles simples en quasi-statique avec un comportement élasto-viscoplastique. / The robust design of mechanical parts consists in modeling the sources of uncertainty.The model becomes fairly representative of the reality in order to reduce safety margins, which guarantee that the operating part will not been at fault.In the case of aerospace parts, a reduction of safety margins is a major economic issue as it leads to a decrease in weight.The probability of failure is a critical quantity in the robust design. It quantifies the risk of failure of the part by comparing the likelihood of resistance of the material (characterized from tests on specimens) with the probability of solicitation of the material, which is determined from external constraints to the part and characteristics of the material. This last problem has been the subject of this thesis.In the case of a non-linear behavior of the material, determining the probability of solicitation requires to run many times a calculation of the part for different values of boundary conditions and parameters values of the material constitutive law.This is quickly becoming out of reach without an appropriate strategy, as one calculation can take up to 12 hours.A strategy dedicated to solving all of these calculations is proposed in this work. It takes advantage of the similarity of the calculations to reduce the total time required. A gain of up to 30 is reached on industrial parts with quasi-static elastic-viscoplastic behavior.
38

On a PGD model order reduction technique for mid-frequency acoustic / Technique de réduction de modèle PGD en acoustique en moyennes fréquences

Barbarulo, Andrea 30 November 2012 (has links)
Aujourd'hui, les outils de simulations numériques sont omniprésents dans l'industrie, que ce soit dans l'industrie aéronautique, aérospatiale, ferroviaire ou automobile.En effet leur utilisation limite la fabrication (souvent très couteuse) de prototype, et permettent ainsi de réduire les couts et d'accélérer la phase de conception d'un nouveau produit.Dans le cadre des applications acoustiques, il est souvent recommandé de calculer la réponse sur l'ensemble de la bande de fréquences d'intérêt.Les outils de simulation numérique sur une bande de fréquences impliquent généralement plusieurs calculs à fréquences fixes.Même si c'est un moyen simple et naturel pour répondre au problème posé, une telle stratégie peut facilement conduire à des calculs énormes. Cela est particulièrement vrai dans la gamme des moyennes fréquences, où la réponse est particulièrement sensible à la fréquence.Dans cette thèse, la PGD (Proper Generalized Decomposition), est appliqué pour trouver une représentation fonctionnelle distincte de la fréquence et de l'amplitude des inconnues de la TVRC (théorie variationnelle des rayons complexes) sur une bande de fréquences donnée.Ceci permet d'obtenir une réponse de haute qualité sur une large bande en moyennes fréquences, sans nécessité de discrétisation fine de la plage de fréquences considérées. En outre, la représentation PGD de la solution permet d'économiser une grande quantité d'espace en terme de stockage de données. Dans un second temps, la technique PGD a été étendue à la stochastique. / In many industrial contexts, such as aerospace applications or cars design, numerical prediction techniquesbecome more and more useful. They restrict the use of real prototypes to a minimum and make easier thedesign phase. In such industries and in the specific for acoustic, engineers are interested in computing theresponses of systems on frequency bands. In order to predict the vibration behavior of systems overfrequency bands, standard numerical techniques usually involve many frequency-fixed computations, atmany different frequencies. Although it is a straightforward and natural mean to answer to the posed problem,such a strategy can easily lead to huge computations, and the amount of data to store often increasessignificantly. This is particularly true in the context of medium frequency bands, where these responses havea strong sensitivity to the frequency. In this work PGD (Proper Generalized Decomposition), in a first time, isapplied to found a separate functional representation over frequency and space of the unknown amplitude ofVTCR (Variational Theory of Complex Rays) formulation on a reduced frequency space. This allows tocalculate an high quality mid-frequency response over a wide band without a fine frequency discretization,saving computational resources. Moreover the PGD representation of the solution allows to save a hugeamount of space in term of stored data. In a second time, PGD technique as been applied to extend itspeculiarity to mid-frequency wide band with uncertainty.
39

Frank O'Hara: A Story in Names

Chatzidimitriou, Romanos January 2019 (has links)
This paper is an analysis of two poems by the American New York School poet Frank O’Hara. The two poems analysed here are “The Day Lady Died” and “Adieu to Norman, Bon Jour to Joan and Jean-Paul.” Both poems have O’Hara’s distinctive ‘I do this, I do that’ style which is characterised by a conversational tone and a narrative of everyday events in New York City. O’Hara’s poetry has long been criticized by the literary community for being targeted to a coterie circle, specifically to his friends and artists in the New York School in the 1950s and early 1960s. Because these criticisms partly derive from the considerable amount of proper names O’Hara includes in many of his poems, the following analysis will be based on the proper names included in the poems. By using two different theories/typologies to analyse the poems, this paper finds the proper name to be a core part of the narrative of the poems and an important source of information for the context in which the poems were written.
40

A Hybrid Optimization Framework with POD-based Order Reduction and Design-Space Evolution Scheme

Ghoman, Satyajit Sudhir 29 May 2013 (has links)
The main objective of this research is to develop an innovative multi-fidelity multi-disciplinary design, analysis and optimization suite that integrates certain solution generation codes and newly developed innovative tools to improve the overall optimization process. The research performed herein is divided into two parts: (1) the development of an MDAO framework by integration of variable fidelity physics-based computational codes, and (2) enhancements to such a framework by incorporating innovative features extending its robustness. The first part of this dissertation describes the development of a conceptual Multi-Fidelity Multi-Strategy and Multi-Disciplinary Design Optimization Environment (M3 DOE), in context of aircraft wing optimization. M3 DOE provides the user a capability to optimize configurations with a choice of (i) the level of fidelity desired, (ii) the use of a single-step or multi-step optimization strategy, and (iii) combination of a series of structural and aerodynamic analyses. The modularity of M3 DOE allows it to be a part of other inclusive optimization frameworks. The M3 DOE is demonstrated within the context of shape and sizing optimization of the wing of a Generic Business Jet aircraft. Two different optimization objectives, viz. dry weight minimization, and cruise range maximization are studied by conducting one low-fidelity and two high-fidelity optimization runs to demonstrate the application scope of M3 DOE. The second part of this dissertation describes the development of an innovative hybrid optimization framework that extends the robustness of M3 DOE by employing a proper orthogonal decomposition-based design-space order reduction scheme combined with the evolutionary algorithm technique. The POD method of extracting dominant modes from an ensemble of candidate configurations is used for the design-space order reduction. The snapshot of candidate population is updated iteratively using evolutionary algorithm technique of fitness-driven retention. This strategy capitalizes on the advantages of evolutionary algorithm as well as POD-based reduced order modeling, while overcoming the shortcomings inherent with these techniques. When linked with M3 DOE, this strategy offers a computationally efficient methodology for problems with high level of complexity and a challenging design-space. This newly developed framework is demonstrated for its robustness on a non-conventional supersonic tailless air vehicle wing shape optimization problem. / Ph. D.

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