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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

The development of analysis of variance techniques for angular data

Harrison, David January 1987 (has links)
In many areas of research, such as within medical statistics, biology and geostatistics, problems arise requiring the analysis of angular (or directional) data. Many possess experimental design problems and require analysis of variance techniques for suitable analysis of the angular data. These techniques have been developed for very limited cases and the sensitivity of such techniques to the violation of assumptions made, and their possible extension to larger experimental models, has yet to be investigated. The general aim of this project is therefore to develop suitable experimental design models and analysis of variance type techniques for the analysis of directional data. Initially a generalised linear modelling approach is used to derive parameter estimates for one-way classification designs leading to maximum likelihood methods. This approach however, when applied to larger experimental designs is shown to be intractable due to optimization problems. The limited analysis of variance techniques presently available for angular data are reviewed and extended to take account of the possible addition of further factors within an experimental design. These are shown to breakdown under varying conditions and question basic underlying assumptions regarding the components within the original approach. A new analysis of variance approach is developed which possesses many desirable properties held in standard 'linear' statistical analysis of variance. Finally several data sets are analysed to support the validity of the new techniques.
32

Síntesis de funciones de seguridad de un sistema eléctrico

Cosgrove Leal, Roberto Fernando January 2007 (has links)
Este trabajo tiene como objetivo fundamental, formular una metodología que permita entregar un conjunto de restricciones a un sistema eléctrico de potencia, tal que se asegure su seguridad y estabilidad. La metodología presentada, puede ser aplicada a cualquier OPF con restricciones de seguridad.
33

Investigação dos limiares dos processos de fragmentação e fusão incompleta / Investigation of thresholds of the processes of fragmentation and incomplete fusion

Nemitala Added 01 March 1991 (has links)
Foram medidas correlações angulares entre C- \'ALFA\' nos sistemas \'ANTPOT. 16,18\'O + \'ANTPOT. 27\'Al e \'ANTPOT. 18\'O + \'ANTPOT. 28\'Si nas energias de 64, 56 e 50 MeV. As partículas pesadas (C) foram detetadas em ângulos próximos ao \"ângulo rasante\" do espalhamento. Os comportamentos das seções de choque dos processos de fusão incompleta e fragmentação em função do ângulo e energia são explciados com base em modelos simples de transferência-evaporação (fusão ncompleta) e decaimento sequencial (excitação-fragmentação) do projétil. / Charged particles angular correlations (C - ) were measured for the 16,18O + 27AI and 16 O + 28Si reactions at 64, 56 and 50 MeV bombarding energies. Heavy fragments (C) were detected near grazing angle. The observed energy dependence of incomplete fusion and projectile fragmen­ tation has been fitted to simple models based on a transfer reemission and projectile sequential decay (excitation-fragmentation) pictures.
34

A Biomechanical Study of Angular Momentum and External Moments During a Ballet Turn

Walters-Stewart, Coren January 2011 (has links)
The following thesis applies equations of motion used in linear locomotion (gait analysis) to the analysis of the purely rotational motion of the fouetté or tour à la seconde. Modifications to the method of analysis include the creation of several MATLAB programs to compute improved estimates of the moment of inertia tensor, three-dimensional angular momentum about the dancer’s centre of mass. The results of this investigation—the quantification of angular momentum and external moments—are compared to similar results from gait analysis to demonstrate how the dancer maintains balance during rotational motion. The variables calculated by the MATLAB programs are particularly relevant in the field of balance control research in the context of inputs into the body’s balance control systems.
35

Perturbed Angular Correlation Studies in Platinum

Kenyon, David Bevan 06 1900 (has links)
<p> Two isotopes of platinum, Pt192 and Pt194, have been investigated using Ge(Li) vs. NaI coincidence techniques. The following corrected angular distributions and mixing ratios in Pt192 were obtained: 468-316 keV A22 = 0.100(8) A44 = 0.011(8) 604-316 keV A22 = -0.410(15) A44 = -0.070(22) 308-612 keV A22 = -0.120(20) A44 = -0.027(20) 417-468 keV A22 = -0.120(26) A44 = -0.110(30) δ308 = -9.4(15) δ604 = + 3(1) |δ417|> 11 g factors for the following five levels of these nuclei were obtained using the method of perturbed angular correlations where the perturbing agent was the hyperfine field on platinum in an iron alloy: Pt192 316 keV g = 0.30(3) Pt192 612 keV g = 0.28(7) Pt192 785 keV g = 0.14(10) Pt194 329 keV g = 0.28(3) Pt194 622 keV g = 0.22(4) A comparison with the predictions of a microscopic collective model, the pairing-plus-quadrupole model, is made. / Thesis / Master of Science (MSc)
36

Nuclear g-Factors in Iron 55 from Perturbed Angular Correlation Studies

Kerr, Peter George 08 1900 (has links)
<p> The (α,n) reaction on natural chromium has been used to study levels in 55Fe up to 2.5 MeV excitation. Intensities and angular distributions of the decay gamma rays were measured, yielding branching and E2/M1 mixing ratios. In a magnetized target of the alloy Cr20Fe80, the rotation of the angular distributions was observed. Using recently determined lifetimes and the average internal field of 277 kOe measured in the target material by Mössbauer absorption, the following g-factors are obtained: - 931 keV, 5/2- -: +1.2 ±0.5 1316 keV, 7/2- -: +0.5 ± 0.5 1408 keV, 7/2- -: -0.77 ± 0.16 </p> / Thesis / Master of Science (MSc)
37

Angular Correlations in Mg24

Mabey, Clive 05 1900 (has links)
<p> A method is described by which spins of nuclear energy levels might be determined, which is a combination of coincidence experiments with Sodium Iodide detectors and angular distribution measurements with high resolution solid state detectors. The method is applied to the 8.87 MeV level in Mg24. </p> / Thesis / Master of Science (MSc)
38

Identificação de matrizes de função de resposta em freqüência multidirecionais em estruturas complexas / Multidirectional frequency response functions matrices assessment in complex structures

Cicogna, Thiago Rodrigo 24 October 2008 (has links)
Este trabalho apresenta o desenvolvimento de uma metodologia para a estimativa de funções de resposta em freqüência angulares (FRFAs). Trata-se de uma técnica que utiliza transdutores piezelétricos (PZT) do tipo bimorph para a medição da curvatura local da estrutura através do potencial elétrico induzido pela extensão e compressão do sensor. A partir da estimativa da curvatura, a rotação pode ser obtida diretamente através de várias técnicas de interpolação (polinomial, formas modais, etc). Apresenta-se a modelagem téorica da qual se deriva as equações que governam a dinâmica de estruturas uni-dimensionais, do tipo viga, e estruturas bidimensionais, do tipo placa, ambas isotrópicas, onde se incorpora o sensor bimorph. Modelos em elementos finitos foram propostos no intuito de avaliar a utilização destes sensores (bimorphs) aplicados à estimativa das FRFAs. Apresentam-se também resultados numéricos e experimentais considerando-se uma viga engastada-livre (cantilever) e resultados numéricos considerando-se uma placa simplesmente apoiada. Um algoritmo genético foi ainda desenvolvido no intuito de determinar a posição e dimensão ótimas dos bimorphs em estruturas do tipo viga. / The present work aims to perform the development of an attractive approach for accurate measurement of angular frequency response functions (AFRFs). It uses bimorph piezoceramic patches to measure the structure\'s local curvature through the measurement of the electric potential induced by the extension and compression of the patch\'s top and bottom stripes, respectively. From this curvature, rotation can be obtained directly by several interpolation techniques (single polynomial, modes basis). Theoretical modeling of the vibration incorporating piezoelectric bimorph sensor is presented and equations governing the dynamics for one-dimensional structures, like a beam, and for two-dimensional structures, like a plate, are derived for isotropic structures. Finite element model for the dynamic analysis were proposed to evaluate bimorphs patches applied to the measurement of angular FRFs. Numerical and experimental results are presented considering a cantilever beam and numerical results for a simply supported plate as tested structured. Also, in this work, a genetic algorithm was used as an adaptive heuristic search algorithm for optimal placement and sizing of the bimorph sensor into beam like structures.
39

Identificação de matrizes de função de resposta em freqüência multidirecionais em estruturas complexas / Multidirectional frequency response functions matrices assessment in complex structures

Thiago Rodrigo Cicogna 24 October 2008 (has links)
Este trabalho apresenta o desenvolvimento de uma metodologia para a estimativa de funções de resposta em freqüência angulares (FRFAs). Trata-se de uma técnica que utiliza transdutores piezelétricos (PZT) do tipo bimorph para a medição da curvatura local da estrutura através do potencial elétrico induzido pela extensão e compressão do sensor. A partir da estimativa da curvatura, a rotação pode ser obtida diretamente através de várias técnicas de interpolação (polinomial, formas modais, etc). Apresenta-se a modelagem téorica da qual se deriva as equações que governam a dinâmica de estruturas uni-dimensionais, do tipo viga, e estruturas bidimensionais, do tipo placa, ambas isotrópicas, onde se incorpora o sensor bimorph. Modelos em elementos finitos foram propostos no intuito de avaliar a utilização destes sensores (bimorphs) aplicados à estimativa das FRFAs. Apresentam-se também resultados numéricos e experimentais considerando-se uma viga engastada-livre (cantilever) e resultados numéricos considerando-se uma placa simplesmente apoiada. Um algoritmo genético foi ainda desenvolvido no intuito de determinar a posição e dimensão ótimas dos bimorphs em estruturas do tipo viga. / The present work aims to perform the development of an attractive approach for accurate measurement of angular frequency response functions (AFRFs). It uses bimorph piezoceramic patches to measure the structure\'s local curvature through the measurement of the electric potential induced by the extension and compression of the patch\'s top and bottom stripes, respectively. From this curvature, rotation can be obtained directly by several interpolation techniques (single polynomial, modes basis). Theoretical modeling of the vibration incorporating piezoelectric bimorph sensor is presented and equations governing the dynamics for one-dimensional structures, like a beam, and for two-dimensional structures, like a plate, are derived for isotropic structures. Finite element model for the dynamic analysis were proposed to evaluate bimorphs patches applied to the measurement of angular FRFs. Numerical and experimental results are presented considering a cantilever beam and numerical results for a simply supported plate as tested structured. Also, in this work, a genetic algorithm was used as an adaptive heuristic search algorithm for optimal placement and sizing of the bimorph sensor into beam like structures.
40

Mancha-angular do feijoeiro-comum: variabilidade genética do patógeno e identificação de marcadores moleculares ligados à resistência / Common bean angular leaf spot pathogen genetic variability and identification of molecular markers associated with resistance

Nietsche, Silvia 02 March 2000 (has links)
Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-10-10T18:16:30Z No. of bitstreams: 1 texto completo.pdf: 13406581 bytes, checksum: 15d4117957a92e914ab43a5c6615e1ba (MD5) / Made available in DSpace on 2017-10-10T18:16:30Z (GMT). No. of bitstreams: 1 texto completo.pdf: 13406581 bytes, checksum: 15d4117957a92e914ab43a5c6615e1ba (MD5) Previous issue date: 2000-03-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A mancha-angular, causada pelo fungo Phaeoisariopsis griseola (Saco) Ferraris, é atualmente uma das principais doenças do feijoeiro no Brasil. O patógeno apresenta alta variabilidade, e o desenvolvimento de novas variedades depende da identificação de novas fontes de resistência. Trabalhos recentes têm demonstrado a alta diversidade genética desse patógeno e a sua co-evolução com os grupos Andino e Mesoamericano de feijoeiro. Trabalhos acerca da herança da resistência a P. griseola têm evidenciado uma herança monogênica dominante em alguns casos e recessiva em outros. Os objetivos dessa série de estudos foram investigar a diversidade genética de P. griseola, determinar a herança da resistência e identificar marcadores RAPD e SCAR ligados ao gene de resistência à mancha-angular no cruzamento entre Rudá e Cornell 49-242. Para avaliar a diversidade genética de isolados de P. griseola coletados no Estado de Minas Gerais e em diversos estados brasileiros. foi utilizada uma série diferenciadora composta de 12 variedades de feijão e marcadores RAPD. Os estudos acerca da diversidade genética confirmaram a 17 raças fisiológicas. O patótipo 63.31 foi a raça que agrupou o maior numero de isolados, estando distribuída em quatro das cinco regiões amostradas. Apenas um isolado apresentou reação de compatibilidade com todos os genótipos da série diferenciadora e foi classificado como do patótipo 63.63, o que indicou a necessidade de inclusão de novos genótipos na série diferenciadora. Por meio do uso do primer OPAA 11 e dos dados do fenótipo de virulência, determinou-se a presença do acervo Mesoamericano no Estado de Minas Gerais. Foram estudados 39 isolados provenientes de diversos estados brasileiros, tendo sido identificados 20 patótipos. Além da determinação da diversidade genética, foram testadas nove potenciais fontes de resistência. 0 cultivar México 54 evidenciou-se como o mais resistente, apresentando reação de incompatibilidade a 20 das 25 raças testadas. Os cultivares AND 277, MAR 2, Cornell 49-242, Bat 332 e G 5686 também se destacaram como boas fontes de resisténcia. O cultivar Rudá foi suscetível à maioria dos isolados testados. Os resultados do estudo de herança indicaram a presença de um gene dominante controlando a resistência à mancha-angular no cultivar Cornell 49-242. Foram mapeados dois marcadores RAPD (OPNOZ 890 e OPEO4 650) ligados em fase de acoplamento a 3,2 e 12,5 CM do gene de resistência. 0 fragmento NOOZ 890 foi transformado em um marcador do tipo SCAR. Foi proposta a designação Phg-2 para o gene de resistência presente no cultivar Cornell 49-242. As análises efetuadas na série diferenciadora indicaram que alguns genótipos não são bons diferenciadores da mancha-angular. Fatores experimentais podem estar contribuindo para uma classificação incorreta dos patótipos de P. griseola. / Angular leaf spot, caused by fungus Phaeoisariopsis griseola (Saco) Ferraris, is one of the most important bean disease in Brazil. The pathogen has demonstrated to be highly variable and breeding programs dependent on the identification of new resistance genes to develop resitant cultivars. Recent studies demonstrated a high genetic diversity of this pathogen and its co- evolution with the Andean and Mesoamerican common bean groups. Several works has demonstrated that resistance to this pathogen has been attributed to one gene, sometimes dominant or recessive. The objective of this study were to determinate the inheritance of the resistance and to identify RAPD and SCARs markers linked to angular leaf spot resistance gene in the cross between Cornell 49 -2424 and Ruda, and to assay the genetic diversity P. griseola isolates from the state of Minas Gerais and from others Brazilian states. A differential series composed of 12 bean varieties and RAPD markers were used. Out of 49 isolates tested in Minas Gerais state, 17 races were identified. Race 63.31 grouped the greatest number of isolates. being distributed in four of the five studied regions. The virulence phenotypes showed a high virulence of the isolates. One isolate presented a reaction of compatibility with all genotypes of the differential series and was classified as being from race 63.63, wich suggest the introduction of the new genotypes in the series. The use of OPAA 11 primer and differential series, suggest the group mesoamerican in Minas Gerais state presence. The genetic diversity of 39 P. griseo/a isolates from the seven brasilian states were studied. The results confirmed a variability of the pathogen in Brazil: in 30 isolates tested, 20 phisiological races were obtained. In this study, not only the determination of the races was carrie out, but also nine potential resistance sources were tested. The results confirmed a variability of the pathogen in Mlnas Gerais state and in Brazil. The Mexico 54 cultivar was the most resistant, pressenting incompatibility reaction to 20 of the 25 races tested. AND 277, MAR-2, Cornell 49-242, BAT 332 and (55686 cultivars were good resistance sources. The cultivar Rudá, type, was susceptible to most of the isolates. In the inheritance study, the results indicated that a single gene dominant controls resistance in Cornell 49-242. Two RAPD markers were mapped OPNo2 ago and OPEO4 650 in coupling phase at 3.2 and 12.5 CM from the resistance gene. The No02 890 fragment was transformed into a SCAR marker and we proposed the designation Phg-2 for the angular leaf spot resistance gene in cultivar Cornell 49-242. The use of RAPD markers and the characterization of the pathotypes of P. griseola indicate the necessity of the substitution of some genotypes and the standardization of the protocols and methodologies related to the characterization of the genetic variability of P. griseola.

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