• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 187
  • 100
  • 52
  • 36
  • 21
  • 13
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 495
  • 65
  • 45
  • 43
  • 43
  • 42
  • 36
  • 36
  • 34
  • 33
  • 33
  • 33
  • 32
  • 31
  • 30
  • 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.
1

Operadores Maximais via método TT*

Oliveira, Lucas da Silva January 2009 (has links)
Desenvolvemos o método TT* , uma técnica baseada na estrutura de espaço de Hilbert dos espaços de funções L², e obtemos resultados sobre a continuidade de operadores maximais definidos sobre esses espaços. Em um segundo momento, fixamos nossa atenção nos operadores maximais direcionais no plano. Definimos uma nova classe de operadores maximais direcionais que generalizam uma introduzida por Córdoba 1971 e provamos sua continuidade em L²(R²). Além disso, obtemos uma prova alternativa e mais simples para o teorema de quase ortogonalidade de Alfonseca, Sória e Vargas. / Primarily, we develop the TT* method, a technique based on the Hilbert space structure of de L² spaces, to establish continuity results for certain maximal operators of interest in Harmonic Analysis and Ergodic Theory. In a second moment, we fix our attention on a special class of maximal operators, the maximal directional operators on the plane. We will define a new class of maximal operators in the plane that generalizes a class introduce earlier by Córdoba and prove sharp estimates on L². Moreover, we obtain a new proof of the optimal result of Alfonseca, Sória e Vargas.
2

Operadores Maximais via método TT*

Oliveira, Lucas da Silva January 2009 (has links)
Desenvolvemos o método TT* , uma técnica baseada na estrutura de espaço de Hilbert dos espaços de funções L², e obtemos resultados sobre a continuidade de operadores maximais definidos sobre esses espaços. Em um segundo momento, fixamos nossa atenção nos operadores maximais direcionais no plano. Definimos uma nova classe de operadores maximais direcionais que generalizam uma introduzida por Córdoba 1971 e provamos sua continuidade em L²(R²). Além disso, obtemos uma prova alternativa e mais simples para o teorema de quase ortogonalidade de Alfonseca, Sória e Vargas. / Primarily, we develop the TT* method, a technique based on the Hilbert space structure of de L² spaces, to establish continuity results for certain maximal operators of interest in Harmonic Analysis and Ergodic Theory. In a second moment, we fix our attention on a special class of maximal operators, the maximal directional operators on the plane. We will define a new class of maximal operators in the plane that generalizes a class introduce earlier by Córdoba and prove sharp estimates on L². Moreover, we obtain a new proof of the optimal result of Alfonseca, Sória e Vargas.
3

Operadores Maximais via método TT*

Oliveira, Lucas da Silva January 2009 (has links)
Desenvolvemos o método TT* , uma técnica baseada na estrutura de espaço de Hilbert dos espaços de funções L², e obtemos resultados sobre a continuidade de operadores maximais definidos sobre esses espaços. Em um segundo momento, fixamos nossa atenção nos operadores maximais direcionais no plano. Definimos uma nova classe de operadores maximais direcionais que generalizam uma introduzida por Córdoba 1971 e provamos sua continuidade em L²(R²). Além disso, obtemos uma prova alternativa e mais simples para o teorema de quase ortogonalidade de Alfonseca, Sória e Vargas. / Primarily, we develop the TT* method, a technique based on the Hilbert space structure of de L² spaces, to establish continuity results for certain maximal operators of interest in Harmonic Analysis and Ergodic Theory. In a second moment, we fix our attention on a special class of maximal operators, the maximal directional operators on the plane. We will define a new class of maximal operators in the plane that generalizes a class introduce earlier by Córdoba and prove sharp estimates on L². Moreover, we obtain a new proof of the optimal result of Alfonseca, Sória e Vargas.
4

On estimates of constants for maximal functions

Iakovlev, Alexander January 2014 (has links)
In this work we will study Hardy-Littlewood maximal function and maximal operator, basing on both classical and most up to date works. In the first chapter we will give definitions for different types of those objects and consider some of their most important properties. The second chapter is entirely devoted to an overview of the fundamental properties of Hardy-Littlewood maximal function, which are strong (p, p) and weak (1, 1) inequalities. Here we list the most actual results on this inequalities in correspondence to the way the maximal func-tion is defined. The third chapter presents the theorem on asymptotic behavior of the lower bound of the constant in the weak-type (1, 1) inequality for the maximal function associated with cubes of Rd, then the dimension d tends to infinity. In the last chapter a method forcomputing constant c, appearing in the main theorem of chapter 3, is given. / <p>QC 20140527</p>
5

Local integrability of strong and iterated maximal functions /

Hagelstein, Paul Alton. January 2000 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Mathematics, June 2000. / Includes bibliographical references. Also available on the Internet.
6

Maximal operators along surfaces of revolution /

Le, Hung Viet. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2000. / Typescript (photocopy). Includes bibliographical references (leaves 29-30). Also available on the World Wide Web.
7

Physiological and Metabolic Responses to Constant-Load Exercise on an Inclined Stepper and Treadmill

Rieger, Brian W. 25 March 1997 (has links)
This study evaluated oxygen uptake (VO2), heart rate (HR), and lactate [HLa] responses between the treadmill (TM) and the CardiosquatTM 1650 LETM inclined stepper by StairMasterTM (SM) during constant-load exercise. The slow component of VO2 (SC) was a central variable assessed during exercise. Twenty-two healthy college-aged (18-30) subjects completed an incremental TM and SM exercise test to establish a workload equivalent to 70% VO2peak. Following each incremental test, a 20-minute constant-load exercise bout was performed . Incremental and instant-load exercise bouts were separated by at least 48 hours. The order of the tests were randomized. VO2, HR, and [HLa] were evaluated at 5, 10, 15, and 20-minutes of exercise. Expired gases were analyzed using a Med Graphics CPX/D metabolic cart. Blood samples were analyzed immediately for lactate concentration with an automated lactate analyzer (Yellow Springs Instrument Model 1500 Sport ). A two-way ANOVA with repeated measures was performed on the rate of change between the treadmill and stepper for VO2, HR, and [HLa]. No significant differences were found for any of the response variables (P>0.05). These results suggest at that the same relative workload, the SM does not elicit a more pronounced SC than the TM. Based on these findings, the SM appears to be an appropriate modality of exercise for various clinical populations. / Master of Science
8

Sobre curvas maximais não recobertas pela curva hermitiana / Over maximal curves cannot be covered by the hermitian curve

Teherán Herrera, Arnoldo Rafael, 1968- 08 June 2014 (has links)
Orientadores: Fernando Eduardo Torres Orihuela, Ercílio Carvalho da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-25T19:08:58Z (GMT). No. of bitstreams: 1 TeheranHerrera_ArnoldoRafael_D.pdf: 1331567 bytes, checksum: 7885ebc0ee3a5a3c7ddbc40bca6def1e (MD5) Previous issue date: 2014 / Resumo: Apresentamos algumas aplicações, especialmente usaremos as curvas construídas para calcular alguns AG códigos num ponto racional; estes serão construídos usando certo semigrupo telescópico no ponto racional da curva correspondente. Finalmente compararemos os parâmetros obtidos de nossos exemplos, com os parâmetros dos códigos existentes na literatura / Abstract: In this thesis we work out exemples of maximal curve wich are not covered by the corresponding Hermitian curve. These exemples arise as covered curves of the called GK curve. We also construct exemples of maximal array which cannot be Galois covered by the corresponding Hermitian curve. Finally we stay some applications to coding theory / Doutorado / Matematica Aplicada / Doutor em Matemática Aplicada
9

Sub-Maximal Exchange Flow over a Sill with Barotropic Forcing

Clouston, Ryan 19 July 2013 (has links)
Two basins separated by a strait often have different densities due to environmental factors, resulting in a situation in the strait where fluids of different densities are essentially side-by-side, causing an exchange flow due to gravitational forces. Dense fluid is pulled below light fluid and the light fluid is pushed above the dense, creating an opposing flow in the two layers. This exchange is often “controlled” at the point in the strait where cross-sectional area is minimized due to a constriction, either horizontal or vertical. Exchange in the strait can control the dynamics, and in turn energy, nutrient, pollutant and biological transport between the basins. Since strait dynamics are often not resolved in regional or global models, it is useful to parameterize the exchange based on external variables such as the density difference in the basins, the level of the dense water in the dense basin, and the tidal forcing. Exchange flow can be “maximal” or “sub-maximal”. The flow is “maximal” if raising the interface in the dense basin (presumably by modifying light water to be dense) does not further increase the exchange flow through the strait. While many ocean straits are usually “maximal”, there are also many that are “sub-maximal,” and thus require separate theoretical treatment. Time-dependent external barotropic forcing (i.e. the tide) modifies the time-averaged exchange flow in a strait. The relationship between tidal forcing and the average exchange flow in a channel has been examined for maximal exchange (Helfrich, 1995). In the present study, that effort is extended to include tidal forcing on a sub-maximal exchange flow. A strait with a sill is simulated numerically, using a two layer hydrostatic approximation. Time-averaged exchange flow increases with tidal amplitude depending on three factors: the physical dimensions of the problem, the tidal amplitude, and the relative strength of flow of the density layers. Results show that all exchange flows increase at a similar rate with tidal forcing, after being normalized by a parameter relating physical dimensions of the strait to the interfacial wave speed. This result quantifies the exchange increase due to tidal forcing for all degrees of “maximality” in this simple sill-only geometry. This relates time-dependent sub-maximal flows to the maximal case that has already been studied in depth. / Graduate / 0415 / ryanpc@uvic.ca
10

Relatively Maximal Covering Spaces

Liebovitz, Morris J. 10 1900 (has links)
This thesis deals with the existence and properties of certain types of covering spaces. It contains the discussion of a generalization of the notion of simple connectedness and several well-known theorems depending on this. / Thesis / Master of Science (MS)

Page generated in 0.0389 seconds