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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.
211

Multi-platform Human Computer Interaction in Converged Media Spaces

Robison, David J., Palmer, Ian J., Excell, Peter S., Earnshaw, Rae A., Al Sheik Salem, Omar F.A. January 2009 (has links)
No / The boundaries between different kinds of media spaces are complex and challenging. The convergence of computing, media, and telecommunications produces environments that contain elements of their origins, but also contain new components that allow interaction in new ways by new users with new kinds of information. This poses problems for effective human computer interaction and human media interaction because the paradigms are not well understood. Converged environments are driving these new uses just as the first PCs supported keyboards and then WIMP interfaces. Traditional models of human computer interaction are not adequate to deal with this complexity, and the shifting of the boundaries brought about by convergence.
212

Parameter sensitivity, estimation and convergence: an information approach

DeBrunner, Victor Earl 14 October 2005 (has links)
Convergence rates are analyzed for Recursive Prediction (Output) Error Methods (RPEM) in the identification of linear state-space systems from (noisy) impulse response data) RPEM algorithms are derived which are suitable for the identification of the parameters in arbitrary state-space structures. Deterministic and stochastic versions of these identification algorithms are presented. These two classes indicate the number of realizations used in the identification, not the presence or absence of noise. The convergence analysis uses the eigen-information of the correlation matrix (really its inverse, the Fisher information matrix) for a chosen parameterization. This analysis explains why various state-space structures have different convergence properties, 1.e., why for the same system the estimation processes corresponding to different identification structures converge at different rates. The eigen-information of the parameter information matrix relates the system sensitivity and numerical conditioning in a manner which provides insight into the identification process. The relevant eigen-information is combined in the proposed scalar convergence time constant +. One important result is that identification of the usually identified direct form II parameters (the standard ARMA parameters) does not necessarily yield the fastest parameter set convergence for the system being identified. Identification from arbitrary input is also briefly considered, as is identification when the model order is different from the “true” system order. / Ph. D.
213

Governance Challenges of Technological Systems Convergence.

Whitman, Jim R. January 2006 (has links)
No / The convergence of several technological systems (especially nanotechnology, biotechnology, information technology, and robotics) has now been adopted as a strategic goal by several countries, most notably the United States and those of the European Union. The anticipated benefits and related fears of competitive disadvantage have brought together a wide range of interested parties, governmental and nongovernmental. In the rush to enter and/or dominate this arena, the benign promise of converging technologies (CT) are highlighted, although a range of risks and less welcome (if difficult to quantify) implications are at best understated. What, then, are the prospects for exercising governance over the technological systems we are busy creating¿and the uses to which they might be put? What will it mean to speak of "global governance" in a world in which the technological promise of CT has been fulfilled?
214

Toward a Convergent Evidence-Based Urban Design Approach

Carney, Mackenzie Amelia 05 June 2023 (has links)
Urban designers do not typically include research or evidence in practice, though the need for an evidence-based approach is becoming increasingly apparent. The way our built environment is constructed affects our health, well-being, and sense of place, as prior research has uncovered. Historically, urban design practice has negatively affected the well-being of urban residents by reinforcing inequitable social and power structures through the design of public space. Some theorists and designers have proposed evidence-based approaches as a response to these concerns. However, the emerging approaches can be disjointed. Tensions arise when deciding between the many types of evidence urban designers can use, and the different ethics they represent. In this thesis, I analyze three existing approaches to evidence-based urban design, including their benefits and their concerns, and ultimately argue that a convergent method is necessary. The conceptual framework I develop is one that responds to concerns of equity and accountability in the built environment, while also maintaining the significance of good design and acknowledging the inevitable integration of technology into society today. / Master of Urban and Regional Planning / Urban design is typically an artistic profession, and conducting or referencing research is not necessarily part of an urban designer's day-to-day. However, the need for a research-backed, or evidence-based, approach to public space design is becoming increasingly apparent. Prior researchers have suggested that the way our cities, neighborhoods, parks, roadways and other public spaces are constructed has an effect on our mental and physical health. Historically, these spaces have been designed to reinforce patterns of social inequity, which has negatively affected the well-being of urban residents. Some theorists and designers have proposed evidence-based approaches as a response to these concerns. However, the emerging approaches towards evidence-based urban design sometimes have conflicting physical and social goals. In this thesis, I analyze three existing approaches to evidence-based urban design, including their benefits and their concerns. I ultimately argue that a new method, which converges the existing methods, is necessary. The conceptual framework I develop is one that responds to concerns of equity and accountability in urban space, maintains the significance of artistry and good design, and acknowledges the inevitable integration of technology into society today.
215

Distinct Element Modeling of the Shimizu Tunnel No.3 in Japan

Vardakos, Sotirios 22 December 2003 (has links)
In the present research a highway twin tunnel project completed in Japan in 1998 is used as a case study to verify results of numerical analyses with measurement data. Each of the tunnels had approximately 1.1 km of length. For this project a wide geometry of approximately 18.0 m was selected by the designers to facilitate three lanes per tunnel. A sequential tunneling technique known in Japan as the "TBM pilot and enlargement method" was used along with NATM principles. The tunnel was used as a reference project, involving performance testing and extensive monitoring in order to verify and standardize support requirements for other tunnels excavated under similar geologic conditions in the Tomei II expressway. The tunnel was excavated in a region consisting mainly of soft sedimentary rocks, such as locally weathered sandstone, underlain by interbedded sandstone and mudstone. Due to observed non symmetric deformations and loads in the tunnel, the distinct element and the convergence-confinement methods were used during the numerical simulations. A parametric analysis was performed initially in a pseudo-continuum approach to study the behavior of the wide tunnel geometry under various conditions. The effects of rock mass elastic modulus, in situ Ko ratio and boundary conditions are discussed. More complex parametric studies were performed in a stochastically generated model by using joint spatial data from geotechnical investigations. The Barton-Bandis constitutive law was assumed for the behavior of the joints. The sensitivity of the ground "characteristic curves" was examined by statistical variation of the joint shear strength parameters. A final simulation using the code UDEC and the convergence-confinement method yields interesting results which are comparable to the monitored data. / Master of Science
216

An Investigation of Points About the Circle of Convergence

Gray, Brucy Clothus 08 1900 (has links)
This paper will be concerned with the convergence of complex power series.
217

Disparités, interactions et convergence régionale en Inde : une approche par l'économétrie spatiale / Disparities, interactions and regional convergence : an approach by spatial econometrics

Hazem, Mohamed 22 October 2010 (has links)
Dans cette thèse, nous avons développé un algorithme de détermination d’une nouvelle forme de la matrice de poids spatiale qui prend en compte aussi bien les effets de proximité spatiale que les critères idiosyndratiques des unités régionales. Ainsi, nous avons proposé une approche originale de détermination d’une forme stationnaire du diagramme de Moran à travers laquelle nous pouvons déterminer les formes des associations spatiales de long terme. En ce sens, nous avons montré la conformité qui peut exister entre les résultats trouvés suite à l’application de cette approche et ceux découlant à partir de l’estimation du modèle de convergence absolue dans un cadre spatial. Dans une autre partie du travail, nous avons proposé deux nouvelles méthodes de détermination des régimes spatiaux sous forme de polarisation et de stratification. Une nouvelle approche de spécification des modèles spatiaux qui se base sur la robustesse du test de Moran dans la détection de l’autocorrélation spatiale globale et le bon choix de la matrice de poids spatiale, a été encore proposée. Nous avons utilisé l’approche d’Analyse Exploratoire des Données Spatiales, l’Approche d’Econométrie Spatiale et les méthodes que nos avons développées pour expliquer les différentes formes de disparités, des interactions spatiales et de convergence régionale en Inde en termes de taux d’alphabétisation au niveau national, pour l’ensemble de la population (Homme et Femme) et au niveau rural et urbain pour l’ensemble des districts sur la période de 1991-2001. Dans la dernière partie du travail, nous avons développé un modèle théorique des facteurs déterminants de l’alphabétisation en Inde. / In this thesis, we have developed an algorithm for determining a new form of the spatial weight matrix that takes into account both the effects of spatial proximity and the idiosyncratic criteria of regional units. Thus, we propose a new approach for determining a stationary form of the Moran scatter plot in which we highlight the forms of steady state spatial associations and the conformity that can exist between the results arising out of this method and those obtained from the model of absolute convergence in a spatial framework. In another part of the thesis, we propose two new methods of determining the spatial regimes in the form of polarization and stratification. A new approach to the specification of spatial models which is based on the robustness of the Moran test in the detection of global spatial autocorrelation and the proper choice of the spatial weight matrix has also been proposed. We used the approach of Exploratory Spatial Data Analysis, Spatial Econometrics approach and methods we developed to explain the different forms of disparities, spatial interaction and regional convergence in India in terms of literacy rate at the national level for the entire population (Male and Female) and rural and urban level for all districts over the period 1991-2001. In the last part of the work, we develop a theoretical model of the determinants of literacy in India.
218

Quelques problèmes de convergence et de récurrence multiple en théorie ergodique / Some problems of multiple convergence and recurrence in ergodic theory

Chu, Qing 06 July 2010 (has links)
Cette thèse est consacrée à l'étude de certaines questions de convergence et de récurrence multiples en théorie ergodique. Nous distinguons les systèmes munis d'une transformation et ceux munis de plusieurs transformations qui commutent. Dans les premiers, le mécanisme de facteurs caractéristiques et les nilsystèmes jouent un rôle important dans l'étude de convergence et de récurrence multiples. À l'aide de ces outils, nous étendons les résultats sur la convergence de moyennes ergodiquesmultiples pondérées de Host et Kra pour le cas linéaire au cas polynômial. En conséquence, nous montrons que pour toute fonction $f$ mesurable bornée sur un système ergodique, la suite $(f(T^n x))$ est universellement bonne pour presque tout $x$. Quand il y a plusieurs transformations qui commutent, à l'aide de la machinerie des systèmes magiques introduite récemment par Host et développée dans cette thèse, nous étendons les résultats sur la convergence de moyennes ergodiques multiples sur les cubes de Host et Kra avec une transformation à plusieurs transformations qui commutent. Nous obtenons aussi un résultat de récurrence multiple quantitatif pour deux transformations qui commutent, similaire en faveur du cas d'une transformation établi par Bergelson, Host et Kra / This thesis is devoted to the study of some questions of multiple convergence and recurrence in ergodic theory. We distinguish between systems endowed with a single transformation and systems endowed with several commuting transformations. In the former, characteristic factors and nilsystemsplay an important role in the study of multiple convergence and recurrence. Using these tools, we extend results on convergence of weighted multiple ergodic averages of Host and Kra for the linear case to the polynomial case. As a consequence, we show that for any bounded measurable function $f$ on an ergodic system, the sequence $f(T^n x)$ is universally good for almost every $x$. In systems endowed with several commuting transformations, we use the machinery of magic systems introduced recently by Host and further properties of magic systems developed in this thesis,to extend results of Host and Kra on convergence of multiple ergodic averages along cubes with a single transformation to commuting transformations. We obtain a quantitative multiple recurrence result for two commuting transformations, similar in flavour to that of a single transformationestablished by Bergelson, Host and Kra, but with a different conclusion
219

Elaboration de solveurs volumes finis 2D/3D pour résoudre le problème de l'élasticité linéaire / Computational 2D/3D finite volume solvers applied to linear elasticity

Martin, Benjamin 19 September 2012 (has links)
Les méthodes classiques de résolution des équations de l'élasticité linéaire sont les méthodes éléments finis. Ces méthodes produisent de très bons résultats et sont très largement analysées mathématiquement pour l'étude des déformations solides. Pour des problèmes de couplage solide/fluide, pour des situations réalistes en présence de discontinuités (modélisation des fronts de gel dans les sols humides), ou bien encore pour des domaines de calcul mieux adaptés aux maillages non conformes, il parait intéressant de disposer de solveurs Volumes Finis. Les méthodes Volumes Finis sont très largement utilisées en mécanique des fluides. Appliquées aux problèmes de convection, elles sont bien adaptées à la capture de solutions présentant des discontinuités et ne nécessitent pas de maillages conformes. De plus, elles présentent l'avantage de conserver au niveau discret les flux à travers les interfaces du maillage. C'est pourquoi sont développées et testées, dans cette thèse, plusieurs méthodes de volumes finis, qui permettent de traiter le problème de l'élasticité. On a, dans un premier temps, mis en œuvre la méthode LSGR (Least Squares Gradient Reconstruction), qui reconstruit des gradients par volumes à partir d'une formule de moindres carrés pondérés sur les volumes voisins. Elle est testée pour des maillages tétraédriques non structurés, et montre un ordre 1 de convergence. La méthode des Volumes Finis mixtes est ensuite présentée, basée sur la conservation d'un flux "pénalisé" à travers les interfaces. Cette pénalisation impose une contrainte sur le type de maillage utilisé, et des tests sont réalisés en 2d avec des maillages structurés et non structurés de quadrangles. On étend ensuite la méthode des Volumes Finis diamants à l'élasticité. Cette méthode détermine un gradient discret sur des sous volumes associés aux interfaces à partir de l'interpolation de la solution aux sommets du maillage. La convergence théorique est prouvée sous réserve de vérifier une condition de coercivité. Les résultats numériques, en 2d pour des maillages non structurés, conduisent à un ordre de convergence meilleur que celui prouvé. Enfin, la méthode DDFV (Discrete Duality Finite Volume), qui est une extension de la méthode Diamant, est présentée. Elle est basée sur une correspondance entre plusieurs maillages afin d'y construire des opérateurs discrets en "dualité discrète". On montre que la méthode est convergente d'ordre 1. Les illustrations numériques, réalisées en 2d et en 3d pour des maillages non structurés, montrent une convergence d'ordre 2, ce qui est fréquemment observé pour cette méthode. / Finite element methods are conventionally used for solving linear elasticity equations. These methods produce very good results and are widely analyzed from a mathematical point of view to study solid deformations. It seems interesting to have Finite Volume solvers for coupled solid/fluid problems, realistic situations in presence of discontinuities (freezing fronts modeling in wet soils), or even to compute fields better suited to non-conforming meshes. Finite Volume methods are widely used in fluid mechanics. Applied to convection problems, they are well suited to compute solutions with discontinuities and do not require mesh conformity. Moreover, they have the advantage of preserving discrete flows across the interfaces of the mesh. Therefore, we develop and test in this thesis several finite volume methods for solving the elasticity problem. First of all, we implement the LSGR method (Least Squares Gradient Reconstruction), which reconstructs gradients by volume from a weighted least squares formula on neighboring volumes. This method has been successfully tested for unstructured tetrahedral meshes, and shows a first-order convergence rate. Then, we present the Mixed Finite Volume method, based on the conservation of a "penalized" flow across the interfaces. The penalty term imposes a constraint on the type of meshes, and numerical tests are performed in 2D with structured and unstructured quadrangles. Afterwards, we extend the diamond-cell Finite Volume method to the elasticity. This method computes a discrete gradient on sub-volumes related to the interfaces from the interpolation of the solution at vertices. The theoretical convergence is proved under a coercivity condition. The numerical results, achieved in 2d for unstructured meshes, give a second-order convergence rate. Finally, we present the DDFV method (Discrete Duality Finite Volume), which is an extension of the precedent one. This method is based on a correspondence between several meshes in order to construct discrete operators on "discrete duality". We show that the DDFV scheme is a first-order convergent method. The 2d and 3d numerical tests on unstructured meshes show a second-order convergence rate, which is a classical result for this method.
220

Optimalité de la Zone Euro? / Optimality of the Euro Zone?

Razanamparany, Haja Mirana 19 January 2012 (has links)
La thèse examine l'optimalité de la Zone Euro une vingtaine d'années après le débat entre la Commission Européenne puis Frankel et Rose (1998) et Krugman (1993). Elle porte principalement sur les membres fondateurs (1980-2010), et s'intéresse secondairement à l'élargissement de la zone monétaire aux PECO. Elle retient un critère transversal d'analyse: la convergence des cycles économiques des pays membres évoqué dès Mundell (1961). L'analyse de la convergence des cycles (corrélation) et des chocs (modèle SVAR) est complétée par celle des déterminants de la première faite à l'aide de modèles à équations simultanées et de modèles dynamiques sur données de panel, ceci afin de répondre à la question de l'endogénéité des critères d'optimalité et ses conditions de réalisation. Enfin, le cas des biens non échangeables mérite d'être étudié à la lumière des caractéristiques de la crise économique de 2007-2008 qui a fortement touché les pays membres en rattrapage. L'analyse de la synchronisation des cycles immobiliers tient compte des caractéristiques particulières du secteur immobilier. La zone montre des divergences qui s'accentuent à nouveau avec la crise actuelle qui met en cause la viabilité de la monnaie unique ainsi que l'optimalité de la zone monétaire. / We examine the optimality of the euro zone two decades after the debate between the European Commission and Frankel and Rose (1998) versus Krugman (1993). The study focuses on the founding members between 1980 and 2010, and it also deals with the expansion of the currency area to CEECs. We retain a main convergence criterion through the analysis: the convergence of business cycles in member countries [Mundell (1961)]. The analysis of the convergence of cycles (with their bilateral correlations) and shocks at their origin (using a SVAR model) is completed by the study of its determinants (using simultaneous equations models and dynamic panel models). We then address the issue of endogeneity of the optimality criteria and its conditions of realization. Finally, the case of the real estate sector deserves to be studied in light of the characteristics of the economic crisis of 2007 - 2008 which has greatly affected catching up members. The analysis of the housing cycles takes also into account the specific characteristics of the housing sector. The area displays differences that are growing again with the crisis and calls upon the viability of the Euro Zone and the optimal currency area.

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