abstract: A simulation study was conducted to explore the influence of partial loading invariance and partial intercept invariance on the latent mean comparison of the second-order factor within a higher-order confirmatory factor analysis (CFA) model. Noninvariant loadings or intercepts were generated to be at one of the two levels or both levels for a second-order CFA model. The numbers and directions of differences in noninvariant loadings or intercepts were also manipulated, along with total sample size and effect size of the second-order factor mean difference. Data were analyzed using correct and incorrect specifications of noninvariant loadings and intercepts. Results summarized across the 5,000 replications in each condition included Type I error rates and powers for the chi-square difference test and the Wald test of the second-order factor mean difference, estimation bias and efficiency for this latent mean difference, and means of the standardized root mean square residual (SRMR) and the root mean square error of approximation (RMSEA). When the model was correctly specified, no obvious estimation bias was observed; when the model was misspecified by constraining noninvariant loadings or intercepts to be equal, the latent mean difference was overestimated if the direction of the difference in loadings or intercepts of was consistent with the direction of the latent mean difference, and vice versa. Increasing the number of noninvariant loadings or intercepts resulted in larger estimation bias if these noninvariant loadings or intercepts were constrained to be equal. Power to detect the latent mean difference was influenced by estimation bias and the estimated variance of the difference in the second-order factor mean, in addition to sample size and effect size. Constraining more parameters to be equal between groups—even when unequal in the population—led to a decrease in the variance of the estimated latent mean difference, which increased power somewhat. Finally, RMSEA was very sensitive for detecting misspecification due to improper equality constraints in all conditions in the current scenario, including the nonzero latent mean difference, but SRMR did not increase as expected when noninvariant parameters were constrained. / Dissertation/Thesis / Masters Thesis Educational Psychology 2016

O objetivo deste trabalho é apresentar algoritmos aplicados para extração de características invariantes à rotação em imagens de impressões digitais. No pré-processamento da imagem utiliza-se detecção de bordas pelo detector de Canny tendo como resultado uma imagem binarizada e afinada. Na extração das minúcias a metodologia adotada é o número de cruzamentos (CN), que extrai os aspectos locais, tais como, as minúcias fim de linha e bifurcações. A direção das cristas locais não é utilizada porque nas imagens rotacionadas a condição de permanência das propriedades biométricas não são satisfeitas. A comparação das impressões digitais utiliza os vetores gerados pela extração de minúcias considerando a posição (x,y) da minúcia armazenada em um vetor por tipo de minúcia (um vetor para crista final e outro vetor para crista bifurcada) e calculando a distância Euclidiana dessa posição (x,y) ao centro de massa da distribuição de minúcias para cada tipo de minúcia. Assim, as duas imagens são similares quando a distância Euclidiana entre os vetores de cada imagem e por tipo de minúcia forem mínimas. São discutidas as limitações de outros trabalhos existentes envolvendo rotação, translação e distorção da imagem de impressão digital, mostrando que os poucos trabalhos que tratam o problema possuem resultados não satisfatórios. Os maiores problemas ocorridos foram a extração de minúcias espúrias, mas foram resolvidos com os métodos sugeridos por Dixon (1979), tendo resultados satisfatórios em duas metodologias. No método média, a precisão para encontrar uma imagem foi de 100%, duas imagens 97,32%, três imagens 92,35%, quatro imagens 86,41% e cinco imagens 71,86%. E no método normal, a precisão para encontrar uma imagem foi de 100%, duas imagens 99,20%, três imagens 96,95%, quatro imagens 94,00% e cinco imagens 76,43%. / The objective of this research is to present algorithms that can be applied in fingerprints images in order to extract certain features, which are invariant to an likely rotation in the given image. In the preprocessing stage, the Canny border detector is used, resulting in a binary, fine tuned image. For the minutiae extraction, the crossing number method is used, which extracts local aspects such as minutiae endings and bifurcations. The direction of local ridges is ignored because, in rotated images, the permanence conditions of the biometric attributes are not fulfilled. The process of matching fingerprints uses two arrays (one for ridge endings and the other for bifurcations), which are generated by the extraction of the minutiae, considering the (x,y) coordinate of the given minutiae stored in the arrays, and calculating its Euclidian distance relating to the center of mass of the minutiae distribution, for each of its types (ending or bifurcation). Thus, both images are similar when the Euclidian distance between the arrays of each image, distinct by the type of each minutiae, is minimal. The limitations of other pieces of research works concerning fingerprint image rotation, translation and distortion are discussed, indicating that the only few ones that deal with these kinds of problems give unsatisfactory results.

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-18T12:14:57Z No. of bitstreams: 1 arquivototal.pdf: 2895129 bytes, checksum: 572a06d99b50bb3cd9314e80d1c5b3c7 (MD5) / Made available in DSpace on 2017-09-18T12:14:57Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2895129 bytes, checksum: 572a06d99b50bb3cd9314e80d1c5b3c7 (MD5) Previous issue date: 2017-07-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / In this dissertation, we study the possibility of violation of the Lorentz invariance taking into account some terms of the standard extended model, more specifically, the part of this model that deals with the extended quantum electrodynamics. We perform quantum corrections in the fermionic sector of the usual quantum electrodynamics added with terms that violate the Lorentz symmetries and in two different configurations. First, the coefficient added and that causes the Lorentz symmetry breaking is introduced th­rough the constant pseudo-tensor Ic juvAp And we treat the constant electric and magnetic fields, that is, we do not evaluate as external leg between the coupling of the photon and fermions, evaluating the field FAp Without opening in term of the gauge field. In the second case, we investigated the operators governed by the coefficient of interaction FAp open in term of the gauge field. In the second case, we investigated the mixed contribu­tion of the minimum and non-minimum coupling. We immediately know that for each coupling evaluated will have their respective vertices. For both cases, we calculate the quantum corrections in a loop. In the first case, the theory with the coefficient Ic juvAp and field FAp without being opened at the end of the gauge field AP, The contribution of a loop and we calculate the counter-ter, having a CPT-par characteristic, which will be useful to be introduced in action to eliminate divergences. In the second case, we examined the contribution of a loop, considering the mixture of minimum and non-minimum coupling, that is, and and and an external one AP, having a CPT-par characteristic, One related to the non-minimum coupling and another to the minimum, respectively and verifying the vertex correction also having the contribution of its counter-term. / Nesta dissertagao, estudamos a possibilidade de violagao da invariancia de Lorentz le­vando em conta alguns termos do modelo padrao estendido, mais especificamente da parte do modelo que trata da eletrodinamica quantica estendida. Realizamos corregoes quanticas no setor fermiOnico da eletrodinamica quantica usual adicionada de termos que violam as simetrias de Lorentz e em duas configuragoes diferentes. Primeiramente, o co­eficiente adicionado e que ocasiona a quebra de simetria de Lorentz é introduzida atraves do pseudo-tensor constante is juvAp e tratamos os campos eletricos e magneticos constantes, ou seja, nao avaliamos como perna externas entre o acoplamento do fOton e fermions, avaliando o campo FAp sem abrir em termo do campo de gauge. No segundo caso, investi­gamos a contribuigao mista do acoplamento minim° e nao-minimo. De imediato sabemos que para cada acoplamento avaliado tera seus respectivo vertices. Para os dois casos, cal­culamos as corregoes quanticas em um lago. No primeiro caso, a teoria com o coeficiente I c juvAp e campo FAp sem ser aberto em termo do campo de gauge AP, a contribuigao de um lago e calculamos a pega de polo, tendo uma caracteristica CPT-par, que sera iltil para ser introduzida na agao para eliminar as divergencias. No segundo caso, nos examinamos a contribuigao de um lago, considerando a mistura dos acoplamento minimo e nao-minimo, ou seja, um Fill, e um externo AP, tendo como caracteristica CPT-impar um relacionado ao acoplamento nao-minimo e outro ao minimo, respectivamente e verificando a corregao de vertice tendo tambem a contribuigao do seu contra termo.

Made available in DSpace on 2014-10-09T12:23:44Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:48Z (GMT). No. of bitstreams: 1 00947.pdf: 5792768 bytes, checksum: 3655a803616339af18a1a368dc3f4567 (MD5) / Thesis / IEA/T / University of Sussex, England

abstract: In order to analyze data from an instrument administered at multiple time points it is a common practice to form composites of the items at each wave and to fit a longitudinal model to the composites. The advantage of using composites of items is that smaller sample sizes are required in contrast to second order models that include the measurement and the structural relationships among the variables. However, the use of composites assumes that longitudinal measurement invariance holds; that is, it is assumed that that the relationships among the items and the latent variables remain constant over time. Previous studies conducted on latent growth models (LGM) have shown that when longitudinal metric invariance is violated, the parameter estimates are biased and that mistaken conclusions about growth can be made. The purpose of the current study was to examine the impact of non-invariant loadings and non-invariant intercepts on two longitudinal models: the LGM and the autoregressive quasi-simplex model (AR quasi-simplex). A second purpose was to determine if there are conditions in which researchers can reach adequate conclusions about stability and growth even in the presence of violations of invariance. A Monte Carlo simulation study was conducted to achieve the purposes. The method consisted of generating items under a linear curve of factors model (COFM) or under the AR quasi-simplex. Composites of the items were formed at each time point and analyzed with a linear LGM or an AR quasi-simplex model. The results showed that AR quasi-simplex model yielded biased path coefficients only in the conditions with large violations of invariance. The fit of the AR quasi-simplex was not affected by violations of invariance. In general, the growth parameter estimates of the LGM were biased under violations of invariance. Further, in the presence of non-invariant loadings the rejection rates of the hypothesis of linear growth increased as the proportion of non-invariant items and as the magnitude of violations of invariance increased. A discussion of the results and limitations of the study are provided as well as general recommendations. / Dissertation/Thesis / Ph.D. Psychology 2013

Estudamos nesta dissertação o conteúdo de operadores da cadeia quântica do modelo XY anisotrópico com interações de três spins (XY triplete anisotrópico). Verificamos que, como no caso de interações de dois spins, este modelo pode ser visto como uma superposição de duas cadeias quânticas Ising, que neste caso apresentam interações de três spins (Ising triplete). Como conseqüência, todo o conteúdo de operadores do modelo XY triplete é obtido através de um estudo sistemático do conteúdo de operadores do Ising triplete o que é feito numericamente explorando-se as relações entre as lacunas de massa e as dimensões anômalas dos operadores do modelo, previstas pela invariância conforme. / We study in this work the operator content of the staggered XY model quantum chain with three-spin interactions (staggered XY triplet). We verified that, as quantum Ising chains, but in this case with three-spin interactions (Ising triplet). It is possible therefore to obtain all the operator content of the XY triplet model by a systematic numerical analysis of the Ising triplet´s operator content, which follows by exploiting the relations between the mass gap amplitudes and the anomalous dimension of the operators of the model, predicted by conformal invariance.

Em decorrência do grande avanço alcançado pela mecânica estatística devido a introdução das idéias de invariância conforme às teorias de escala para sistemas finitos, retomamos, neste trabalho, o estudo do modelo XY em campo transverso. A princípio, apresentamos uma análise detalhada do comportamento \"crossover\" característico do modelo, onde incluímos cálculos melhorados dos expoentes da susceptibilidade e do gap de energia anteriormente apresentados por dos Santos e Stinch-combe. Em seguida, uma análise numérica do espectro foi desenvolvida, considerando-se condições livres de contorno, e comparada com as previsões da invariância conforme. Finalmente, as correções à energia do estado fundamental de cadeias finitas foram utilizadas para obter o parâmetro que caracteriza as classes de universalidade (a carga central c). / In view of the great advance attached from statistical mechanics due to the conformal invariance ideas introduced to the scale theories, we take over at this work, the study of the XY model in a transverse field. At first, we present a detailed analysis on the sample\'s typical crossover behavior. An improved calculation of the susceptibility and gap exponents early presented by dos Santos and Stinchcombe is included. Nest, a numerical analysis of the spectrum, regarding free boundary condi¬tions was developed and compared with conformal invariance predictions. Finally, the fundamental state energy corrections of finite chains were used to obtain the parameter which ,distingoishes the universality classes (the central charge c).

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / PadrÃes de invariÃncia de escala, associados à leis de potÃncia, sÃo frequentemente observados na natureza. Alguns exemplos sÃo: flutuaÃÃes em preÃos de itens de bolsa de valores e outros investimentos, alÃm do espectro de energia em sistemas turbulentos. Esses dois sistemas e vÃrios outros que exibem invariÃncia de escala tÃm propriedades em comum: compÃem-se de vÃrios elementos que interagem de forma nÃo linear, estÃo fora do equilÃbrio e exibem auto-organizaÃÃo. InvariÃncia de escala tambÃm à encontrada nas correlaÃÃes observadas no ponto crÃtico de sistemas que apresentam transiÃÃes de fase. O conceito de criticalidade auto-organizada sugere que as propriedades de invariÃncia emergem espontaneamente em sistema complexos. VÃrios modelos exibem propriedades criticamente auto-organizadas, entre eles percolaÃÃo invasiva, pilhas de areia e o modelo de desnÃveis, no entanto, nÃo se sabe ao certo quais os ingredientes necessÃrios para criticalidade emergir. Sabe-se que essa propriedade se manifesta em alguns sistemas difusivos nÃo lineares. Nesse trabalho, introduzimos um potencial confinante em um modelo de difusÃo unidimensional com uma nÃo linearidade singular no coeficiente de difusÃo e analisamos a influÃncia dessa mudanÃa no estado estacionÃrio do sistema. Conseguimos, entÃo, derivar uma equaÃÃo de difusÃo do modelo e obtemos uma soluÃÃo para o perfil de densidade. Nossa soluÃÃo analÃtica concorda perfeitamente com os resultados numÃricos. Fizemos, ainda, um estudo estatÃstico do perfil de avalanches do modelo, e obtemos perfis de avalanche em leis de potÃncia, o que normalmente nÃo à observado em outros sistemas unidimensionais. Analisamos, ainda, como esses perfis variam na medida que se aumenta o confinamento, e usando transformaÃÃes de escala encontramos uma curva universal para os perfis de distribuiÃÃo de tamanhos de avalanche. Nossos resultados demonstram que a aÃÃo do confinamento em um sistema unidimensional pode levar ao surgimento da invariÃncia de escala. / Patterns of scale invariance, associated with power laws, are often found in nature, for instance, in the fluctuations of prices of items in stock markets and in the energy spectrum of turbulent systems. These two systems and many others that exhibit scale invariance present some common properties: they are comprised of several elements that interact in a non-linear way, are not in equilibrium, and exhibit self-organization. Scale invariance is also found in the correlations observed in the critical state of systems that present phase transitions. The concept of self-organized criticality suggests that the properties of invariance spontaneously arise in complex systems. Several models exhibit properties of self-organized critically, including invasion percolation, sand-piles and the trough model, however it is not clear what are the necessary ingredients for criticality to arise. It is known that this property appears in some non-linear diffusive systems. In this work, we introduce a confining potential in a one-dimensional diffusion model with a singular non-linearity on diffusion coefficient, and analyze how this affects in the steady state of the system. We then derive a diffusion equation and obtain a solution for stationary density profile. Our analytical solution is in good agreement with the numerical results. We also present a statistical study of the distribution of avalanches sizes in this model, and obtain profiles following power laws, what is not usually observed in other one-dimensional systems. We also investigated how these profiles vary when the confinement increases, and using finite size scaling we found a universal curve for the distribution of avalanche sizes. Our results show that the action of confinement in a one-dimensional system can yield scale invariance.

O conceito de indistinguibilidade em uma estrutura, entendido como invariância sob os automorfismos dessa estrutura, é apresentado, analisado e aplicado ao exa me do problema filosófico dos objetos indistinguíveis. Especialmente considerada é a versão desse problema que aparece na teoria quântica. / The concept of indistinguishability in a structure, understood as invariance under the automorphisms of that structure, is presented, analysed and applied to the examination of the philosophical problem of indistinguishable objects. Specially considered is the version of this problem that appears in the quantum theory.

Made available in DSpace on 2014-10-09T12:23:44Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:48Z (GMT). No. of bitstreams: 1 00947.pdf: 5792768 bytes, checksum: 3655a803616339af18a1a368dc3f4567 (MD5) / Thesis / IEA/T / University of Sussex, England