• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 51
  • 40
  • 32
  • 7
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 151
  • 33
  • 22
  • 16
  • 16
  • 13
  • 12
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • 10
  • 10
  • 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.
11

Density stratification and associated front in Liverpool bay

Czitrom Baus, S. P. R. January 1982 (has links)
No description available.
12

Numerical simulation of frontogenesis using the finite-element method

Koclas, Pierre, 1957- January 1981 (has links)
No description available.
13

Zhong gong "tong yi zhan xian" zhi yan jiu

Qu, Guofan. January 1900 (has links)
Thesis (M.A.)--Zheng zhi zuo zhan xue xiao. / Reproduced from typescript. Bibliography: leaves 99-102.
14

Colonização estatal no noroeste paulista : fazenda Jacylândia no município de Meridiano-SP /

Barbudo, Reolarde Ramalho. January 2002 (has links)
Orientador: Márcio Antônio Teixeira / Banca: Antônio Nivaldo Hespanhol / Banca: Sônia Maria Pessoa Pereira Bergamasco / Resumo: Este trabalho tem como objetivo a análise dos movimentos de ocupação pelas frentes pioneiras de colonização (1940-1960),que contribuíram para a apropriação e valorização das terras do Noroeste Paulista, identificando o momento dos conflitos reivindicatórios e o papel dos órgãos públicos na consolidação do projeto de colonização da Gleba 06 - Fazenda Jacylândia no município de Meridiano, estado de São Paulo . O estudo revela a evolução da estrutura agrária e fundiária, seu suporte legal no tocante a Fazenda, município e região, e analisa a situação atual dos sitiantes-residentes da Fazenda face às políticas agrárias vigentes. A localização da Fazenda (proximidade dos núcleos urbanos), o desgaste da terra, o predomínio do minifúndio, a morosidade das decisões políticas do Estado, a falta de recursos econômicos, apontou para a busca de alternativas e estratégias de sobrevivência e inclusões de atividades não-agrícolas que apontam para um "novo rural" - polissêmico. / Abstract: This work has as its purpose to analyse the movements of occupation done by the pioneer fronts of colonization (1940 - 1960), that contributed for the possession and valuation of the lands on Noroeste Paulista, by identifying the moments of the reivindicative conflicts and the role of the public organisms for the consolidation of the colonization project of the Glebe 6 - Jacylândia Farm, in the municipality of Meridiano, São Paulo state. This study shows the evolution of the agrarian, landed structure, its legal support concerning to the Farm, the municipality and the region, and it evaluates the present situation of the small farmers living on the Farm before the agrarian politics in vigor. The localization of the Farm (near the urban nuclei), the wearing of the lands, the prevalence of the small properties, the slowness of the political actions of the State, the lack of economic funds indicated the search of options and survival strategies through the non-agricultural activities that pointed towards a polysemic "new rural". / Mestre
15

Cast-Iron Facades in Texas

Giritz, Cheryl A. 12 1900 (has links)
In this limited survey, nineteenth-century cast-iron facades in Texas were recorded and compared to iron-fronted buildings in New York City. It was found that generally, the still existing buildings in Texas cities and towns were similar to those in New York in style but differed to the extent to which the cast-iron elements were used. None of the existing iron facades in Texas used iron as support beyond the first floor of the facade. This held true even in multi-storied buildings in Texas where cast-iron columns on the first floor carried the weight of a brick facade on the upper floors. It appears that nineteenth-century builders in Texas knew of New York trends but had definite regional preferences.
16

On the generation of waves during frontogenesis

Shakespeare, Callum January 2015 (has links)
Density fronts are ubiquitous features of the ocean and atmosphere boundary layers. Boundary layers are characterised by strong surface fluxes of heat, water and momentum, and exhibit intense eddy fields that are associated with strong horizontal strains. Such boundary layer phenomena can drive the generation and sharpening of frontal density gradients in a process known as frontogenesis. Analytic models of frontogenesis have typically employed the `two-dimensional front' configuration where the density front is assumed to be infinitely long and straight, such that gradients along the front may be neglected, and the mathematical problem reduced to two spatial dimensions. Hoskins and Bretherton (1972) used this configuration to demonstrate how a weak background strain flow, associated with a large scale weather system, can drive the collapse of a boundary front to a discontinuity in the inviscid equations in finite time. More recently, Blumen (2000) has used the same configuration to demonstrate how an unbalanced initial state --- associated with a rapidly applied boundary flux --- can trigger an adjustment process which drives frontogenesis on the boundary. These two types of frontogenesis are known as `forced' and `spontaneous', respectively. Forced and spontaneous frontogenesis have typically been studied in isolation, despite it being well established that they can and do occur simultaneously. Furthermore, neither the Hoskins and Bretherton (1972) nor Blumen (2000) models include propagating inertia-gravity waves, despite recent observations and numerical simulations showing that these waves are often generated during active frontogenesis. Here we formulate a generalised mathematical model for the classical two-dimensional density front subject to a simple background strain flow, as studied by Hoskins and Bretherton (1972) . This model firstly unifies the disparate frontogenesis theories of Hoskins and Bretherton (1972) and Blumen (2000). Secondly, the model extends these theories by permitting arbitrary initial conditions, stratification and strong strains. Thirdly, the model incorporates non-hydrostatic effects and unbounded domains. An important novel feature of the model is the accurate description of inertia-gravity wave generation during frontogenesis. We show that these waves can be generated both by the geostrophic adjustment of initial imbalances in a stratified ambient, and spontaneously due to the acceleration of the strain flow around the front. The generalised model thus provides a unified theory capable of describing frontogenesis and wave generation in the atmosphere and ocean boundary layers on a vast range of scales. In particular, the inclusion of strong strains permits the description of frontogenesis on the ocean submesoscale. The predictions of the generalised model are confirmed by comparison with a suite of fully non-linear numerical simulations.
17

Heat, moisture, and momentum budgets for an Oklahoma squall line.

Stokes, Judith January 1976 (has links)
Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography: leaves 38-39. / M.S.
18

Numerical simulation of frontogenesis using the finite-element method

Koclas, Pierre, 1957- January 1981 (has links)
No description available.
19

Antarctic intermediate water and the Antarctic circumpolar current in the Southwest Atlantic

Marwood, Tim January 2000 (has links)
No description available.
20

Architectural exploration methods and tools for heterogeneous 3D-IC

Frantz Ferreira, Felipe 26 October 2012 (has links)
L'intégration tridimensionnelle (3D), où plusieurs puces sont empilées et interconnectées, est en train de révolutionner l'industrie des semi-conducteurs.Cette technologie permet d'associer, dans un même boîtier, des puces électroniques (analogique, numérique, mémoire) avec des puces d'autres domaines(MEMS, bio-capteurs, optique, etc). Cela ouvre de nombreuses voies d'innovation. Néanmoins, l'absence d'outils de conception assistée ordinateur(CAO) adaptés aux systèmes 3D freine l'adoption de la technologie.Cette thèse contribue à deux problématiques liées à la conception 3D : le partitionnement d'un système sur de multiples puces et l'optimisation hiérarchique de systèmes multiphysiques (hétérogènes).La première partie de la thèse est dédiée au problème de partitionner la fonctionnalité d'un système sur de multiples puces. Un outil de « floorplan » 3D a été développé pour optimiser ce partitionnement en fonction de la surface des puces, de la température d'opération du circuit et de la structure des interconnexions. Ce type d'outil étant complexe, nous proposons de régler ses paramètres de façon automatique par l'utilisation d'algorithmes évolutionnaires.Des résultats expérimentaux sur une suite de benchmarks et sur une architecture multi processeur connecté en réseau démontrent l'efficacité et l'applicabilité des techniques d'optimisation proposées.Dans la deuxième partie, nous présentons une méthodologie de conception hiérarchique qui est adaptée aux systèmes hétérogènes. La méthode combine une approche ascendante et descendante et utilise des courbes de compromis(Fronts de Pareto) comme une abstraction de la performance d'un circuit.La contribution principale de la thèse consiste à utiliser des techniques d'interpolation pour représenter les Fronts de Pareto par des fonctions continues et à leur intégration dans des processus d'optimisation classiques. Cela permet un gain en flexibilité lors de l'étape ascendante du flot (caractérisation) et un gain en temps lors de l'étape descendante (synthèse). Le flot de conception est démontré sur un amplificateur opérationnel ainsi comme sur la synthèse d'un lien optoélectronique avec trois niveaux hiérarchiques. / 3D integration technology is driving a strong paradigm shift in the design of electronic systems. The ability to tightly integrate functions from different technology nodes (analog, digital, memory) and physical domains (MEMS, optics, etc) offers great opportunities for innovation (More than Moore). However, leveraging this potential requires efficient CAD tools to compare architectural choices at early design stages and to co-optimize multiphysics systems.This thesis work is divided into two parts. The first part is dedicated to the problem of partitioning a system into multiple dies. A 3D floorplanning tool was developed to optimize area, temperature and the interconnect structure of a 3DIC. Moreover, a meta-optimization approach based on genetic algorithms is proposed to automatically configure the key parameters of the floorplanner. Tests were carried out on architectural benchmarks and a NoC based multiprocessor to demonstrate the efficiency of the proposed techniques.In the second part of the thesis, a hierarchical design methodology adapted to heterogeneous systems is presented. The method combines the bottom-up and top-down approaches with Pareto-front techniques and response surface modeling. The Pareto front of lower level blocks are extracted and converted into predictive performance models that can be stored and reused in a top-down optimization process. The design flow is demonstrated on an operational amplifier as well as on the synthesis of an optoelectronic data link with three abstraction levels.

Page generated in 0.0603 seconds