970 resultados para Classical testing theory
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We construct exact vortex solutions in 3+1 dimensions to a theory which is an extension, due to Gies, of the Skyrme-Faddeev model, and that is believed to describe some aspects of the low energy limit of the pure SU(2) Yang-Mills theory. Despite the efforts in the last decades those are the first exact analytical solutions to be constructed for such type of theory. The exact vortices appear in a very particular sector of the theory characterized by special values of the coupling constants, and by a constraint that leads to an infinite number of conserved charges. The theory is scale invariant in that sector, and the solutions satisfy Bogomolny type equations. The energy of the static vortex is proportional to its topological charge, and waves can travel with the speed of light along them, adding to the energy a term proportional to a U(1) No ether charge they create. We believe such vortices may play a role in the strong coupling regime of the pure SU(2) Yang-Mills theory.
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We construct static soliton solutions with non-zero Hopf topological charges to a theory which is the extended Skyrme-Faddeev model with a further quartic term in derivatives. We use an axially symmetric ansatz based on toroidal coordinates, and solve the resulting two coupled nonlinear partial differential equations in two variables by a successive over-relaxation method. We construct numerical solutions with the Hopf charge up to 4. The solutions present an interesting behavior under the changes of a special combination of the coupling constants of the quartic terms.
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The internet has revolutionized the way we socialize, and as a consequence the way to love. The new communication technologies have facilitated intercultural relationships. Nowadays family relations are one of the major factors in immigration to European countries. Family relations means persons who arrive as family dependents and in accordance with laws regulating family reunification. This thesis aims to apply the classical assimilation theory stated by Milton Gordon (1964), which formulates a series of assimilation stages through which an individual must pass in order to be completely assimilated. In accordance with this theory, marriage is the final phase for a newcomer to fully incorporate into the host society. Thus, based on this presumption and other contemporary theories, the present study has analysed how women who get involved in intercultural marriages based on internet meeting experience these assimilation stages and evaluated the resources used by respondents to incorporate themselves into Swedish society.The main goal of the study was to determine if jumping to the last stage of assimilation does assure the incorporation in the social or/and labour spheres and the findings demonstrate that even though husbands are a valuable resource for assimilation, several cultural issues in Swedish society make it difficult to assure success for the newcomers.On the other hand, Sweden is a country with a strong national sentiment and the assimilation of immigrants still is an important issue to deal with. The Swedish Integration Board has disappeared and major projects for integration have been left in the hands of the municipalities or the Migration Board, institutions that still do not know how to deal with this dilemma.
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o objetivo desta dissertação é analisar como se configuram as funções '< administrativas de planejamento, organização, direção e controle, nas equipes funcionais em nível operacional do Banco Central do Brasil, em função do grau de racionalidade comunicativa I. que referencia a ação gerencial. A partir dos conceitos de processo administrativo e de suas funções integrantes, decorrentes da teoria clássica da administração, a ação gerencial é analisada à luz da epistemologia crítica, particularmente quanto aos conceitos de racionalidade comunicativa e das categorias de ação social. A pesquisa classifica-se como explicativa quanto aos fins e utiliza-se do método de estudo de caso, pois a análise é ambientada nas equipes de trabalho em nível operacional do Banco Central do Brasil. Os dados foram coletados por meio de aplicação de questionário junto aos servidores da instituição que trabalham nos componentes administrativos denominados "Coordenadorias". A partir desses dados foi possível a validação", das escalas e das correlações estabelecidas entre os construtos integrantes do modelo de pesquisa. Os resultados obtidos permitiram confirmar e discutir a hipótese principal do presente estudo de que a racionalidade comunicativa é preditora dos atributos das funções administrativas de planejamento, organização, direção e controle nas equipes funcionais em nível operacional do Banco Central.
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Lucas (2000) estimates that the US welfare costs of inflation are around 1% of GDP. This measurement is consistent with a speci…c distorting channel in terms of the Bailey triangle under the demand for monetary base schedule (outside money): the displacement of resources from the production of consumption goods to the household transaction time à la Baumol. Here, we consider also several new types of distortions in the manufacturing and banking industries. Our new evidences show that both banks and firms demand special occupational employments to avoid the inflation tax. We de…ne the concept of ”the foat labor”: The occupational employments that are aflected by the in‡ation rates. More administrative workers are hired relatively to the bluecollar workers for producing consumption goods. This new phenomenon makes the manufacturing industry more roundabout. To take into account this new stylized fact and others, we redo at same time both ”The model 5: A Banking Sector -2” formulated by Lucas (1993) and ”The Competitive Banking System” proposed by Yoshino (1993). This modelling allows us to characterize better the new types of misallocations. We …nd that the maximum value of the resources wasted by the US economy happened in the years 1980-81, after the 2nd oil shock. In these years, we estimate the excess resources that are allocated for every speci…c distorting channel: i) The US commercial banks spent additional resources of around 2% of GDP; ii) For the purpose of the firm foating time were used between 2.4% and 4.1% of GDP); and iii) For the household transaction time were allocated between 3.1% and 4.5 % of GDP. The Bailey triangle under the demand for the monetary base schedule represented around 1% of GDP, which is consistent with Lucas (2000). We estimate that the US total welfare costs of in‡ation were around 10% of GDP in terms of the consumption goods foregone. The big di¤erence between our results and Lucas (2000) are mainly due to the Harberger triangle in the market for loans (inside money) which makes part of the household transaction time, of the …rm ‡oat labor and of the distortion in the banking industry. This triangle arises due to the widening interest rates spread in the presence of a distorting inflation tax and under a fractionally reserve system. The Harberger triangle can represent 80% of the total welfare costs of inflation while the remaining percentage is split almost equally between the Bailey triangle and the resources used for the bank services. Finally, we formulate several theorems in terms of the optimal nonneutral monetary policy so as to compare with the classical monetary theory.
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Apesar do crescente interesse no conceito de engajamento da marca ainda existe discordância quanto aos seus conceitos fundamentais. Esta tese de doutorado explora a natureza da construção engajamento da marca do consumidor (EMC). No primeiro artigo, EMC é avaliada no âmbito da Teoria da Expectância para explicar e esclarecer como a antecipação de possíveis resultados de se envolver com uma marca, sendo tais resultados classificados como “primeiro nível” (resultante do esforço pessoal alocado para interagir com uma marca) e “segundo nível” (ou nível final, representando a consequência dos resultados de primeiro nível) e uma nova definição de EMC é formulada. Um arcabouço teórico abrangente é proposto para engajamento da marca, usando o Teoria Organizacional de Marketing para Expansão de Fronteiras (TOMEF) como referência para os pontos de contato entre o consumidor e a marca. A partir dos fundamentos teóricos das dimensões cognitivas, emocionais e comportamentais do EMC, quinze proposições teóricas são desenvolvidas para incorporar uma perspectiva multilateral às doutrinas teóricas do construto. No segundo artigo, quatro estudos são usados para desenvolver uma escala de engajamento da marca do consumidor. O Estudo 1 (n = 11) utiliza revisão da literatura e entrevistas em profundidade com os consumidores para gerar os itens da escala. No Estudo 2, oito especialistas avaliam 144 itens quanto a validade de face e validade de conteúdo. No Estudo 3 dados coletados com alunos de graduação (n = 172) é submetida à análise fatorial exploratória (AFE) e confirmatória (AFC) para redução adicional de itens. Trezentos e oitenta e nove respostas de um painel de consumidores são usados no Estudo 4 para avaliar o ajuste do modelo, usando a análise fatorial confirmatória (AFC) e Modelagem por Equações Estruturais (MEE). A escala proposta possui excelentes níveis de validade e confiabilidade. Finalmente, no terceiro papel, uma escala de engajamento do consumidor de Vivek et al. (2014) é replicada (n = 598) junto à consumidores em uma feira automotiva, para estender o debate sobre formas de medição do constructo usando a perspectiva da Teoria de Resposta ao Item (TRI). Embora o modelo desenvolvido com base na teoria clássica de teste (TCT) usando AFC, um modelo de resposta gradual (MRG) identifica cinco itens que têm baixos níveis de poder discriminante e com baixos níveis de informação. A abordagem usando TRI indica um possível caminho para melhorias metodológicas futuras para as escalas desenvolvidas na área de marketing em geral, e para a escala engajamento do consumidor, em particular.
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In this dissertation, the theoretical principles governing the molecular modeling were applied for electronic characterization of oligopeptide α3 and its variants (5Q, 7Q)-α3, as well as in the quantum description of the interaction of the aminoglycoside hygromycin B and the 30S subunit of bacterial ribosome. In the first study, the linear and neutral dipeptides which make up the mentioned oligopeptides were modeled and then optimized for a structure of lower potential energy and appropriate dihedral angles. In this case, three subsequent geometric optimization processes, based on classical Newtonian theory, the semi-empirical and density functional theory (DFT), explore the energy landscape of each dipeptide during the search of ideal minimum energy structures. Finally, great conformers were described about its electrostatic potential, ionization energy (amino acids), and frontier molecular orbitals and hopping term. From the hopping terms described in this study, it was possible in subsequent studies to characterize the charge transport propertie of these peptides models. It envisioned a new biosensor technology capable of diagnosing amyloid diseases, related to an accumulation of misshapen proteins, based on the conductivity displayed by proteins of the patient. In a second step of this dissertation, a study carried out by quantum molecular modeling of the interaction energy of an antibiotic ribosomal aminoglicosídico on your receiver. It is known that the hygromycin B (hygB) is an aminoglycoside antibiotic that affects ribosomal translocation by direct interaction with the small subunit of the bacterial ribosome (30S), specifically with nucleotides in helix 44 of the 16S ribosomal RNA (16S rRNA). Due to strong electrostatic character of this connection, it was proposed an energetic investigation of the binding mechanism of this complex using different values of dielectric constants (ε = 0, 4, 10, 20 and 40), which have been widely used to study the electrostatic properties of biomolecules. For this, increasing radii centered on the hygB centroid were measured from the 30S-hygB crystal structure (1HNZ.pdb), and only the individual interaction energy of each enclosed nucleotide was determined for quantum calculations using molecular fractionation with conjugate caps (MFCC) strategy. It was noticed that the dielectric constants underestimated the energies of individual interactions, allowing the convergence state is achieved quickly. But only for ε = 40, the total binding energy of drug-receptor interaction is stabilized at r = 18A, which provided an appropriate binding pocket because it encompassed the main residues that interact more strongly with the hygB - C1403, C1404, G1405, A1493, G1494, U1495, U1498 and C1496. Thus, the dielectric constant ≈ 40 is ideal for the treatment of systems with many electrical charges. By comparing the individual binding energies of 16S rRNA nucleotides with the experimental tests that determine the minimum inhibitory concentration (MIC) of hygB, it is believed that those residues with high binding values generated bacterial resistance to the drug when mutated. With the same reasoning, since those with low interaction energy do not influence effectively the affinity of the hygB in its binding site, there is no loss of effectiveness if they were replaced.
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How ecologically similar species are able to coexist has always generated great interest in the scientific community. Classical niche theory predicts that species coexistence is only possible when they segregate in at least one dimension of the ecological niche, thus leading to ecological differentiation among species. However, recent work has shown that species that are more similar in some ecological traits are the ones more prone to be able to coexist (environmental filter). The knowledge of how these forces act shaping ecological communities can reveal co-existence strategies, providing important information for management and conservation of the species. This study tested these hypotheses using a pair of coexisting species of Herpsilochmus, H. pectoralis and H. sellowi. In this study I use high resolution (50 x 50 m) ecological niche models to Identify which environmental factors best predict species occurrence. Next, I calculate the overlap in habitat use by species and build null models to test the hypothesis of spatial niche segregation. In addition, I obtain the selectivity parameters of habitat use to test whether the species H. pectoralis (larger body size) is less selective than H. sellowi (smaller body size) as stated in the literature for other species. The results reject the ecological equivalence among species, revealing that the species of Herpsilochmus explore the habitat differently, having different environmental niches. The hypothesis of environmental filter was not observed in my analysis, the observed overlap in habitat use among species was lower than expected by chance. Evidence that Herpsilochmus are spatially segregating reinforces the hypothesis of interspecific competition as the predominant force in the selection of microhabitat of the species. However, more data and experiments are necessary to state categorically that the observed pattern is a result of current or past competition
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The objective of this dissertation is the development of a general formalism to analyze the thermodynamical properties of a photon gas under the context of nonlinear electrodynamics (NLED). To this end it is obtained, through the systematic analysis of Maxwell s electromagnetism (EM) properties, the general dependence of the Lagrangian that describes this kind of theories. From this Lagrangian and in the background of classical field theory, we derive the general dispersion relation that photons must obey in terms of a background field and the NLED properties. It is important to note that, in order to achieve this result, an aproximation has been made in order to allow the separation of the total electromagnetic field into a strong background electromagnetic field and a perturbation. Once the dispersion relation is in hand, the usual Bose-Einstein statistical procedure is followed through which the thermodynamical properties, energy density and pressure relations are obtained. An important result of this work is the fact that equation of state remains identical to the one obtained under EM. Then, two examples are made where the thermodynamic properties are explicitly derived in the context of two NLED, Born-Infelds and a quadratic approximation. The choice of the first one is due to the vast appearance in literature and, the second one, because it is a first order approximation of a large class of NLED. Ultimately, both are chosen because of their simplicity. Finally, the results are compared to EM and interpreted, suggesting possible tests to verify the internal consistency of NLED and motivating further developement into the formalism s quantum case
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A fundamental action, representing a mass dimension-transmuting operator between Dirac and ELKO spinor fields, is performed on the Dirac Lagrangian, in order to lead it into the ELKO Lagrangian. Such a dynamical transformation can be seen as a natural extension of the Standard Model that incorporates dark matter fields. The action of the mass dimension-transmuting operator on a Dirac spinor field, that de fines and introduces such a mapping, is shown to be a composition of the Dirac operator and the nonunitary transformation that maps Dirac spinor fields into ELKO spinor fields, de fined in J. Math. Phys. 4 8, 123517 (2007). This paper gives allowance for ELKO, as a candidate to describe dark matter, to be incorporated in the Standard Model. It is intended to present for the first time, up to our knowledge, the dynamical character of a mapping between Dirac and ELKO spinor fields, transmuting the mass dimension of spin one-half fermionic fields from 3/2 to 1 and from 1 to 3/2.
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In the classical pure spinor worldsheet theory of AdS(5) x S-5 there are some vertex operators which do not correspond to any physical excitations. We study their flat space limit. We find that the BRST operator of the worldsheet theory in flat space-time can be nontrivially deformed without deforming the worldsheet action. Some of these deformations describe the linear dilaton background. But the deformation corresponding to the nonphysical vertex differs from the linear dilaton in not being worldsheet parity even. The nonphysically deformed worldsheet theory has nonzero beta-function at one loop. This means that the classical Type IIB SUGRA backgrounds are not completely characterized by requiring the BRST symmetry of the classical worldsheet theory; it is also necessary to require the vanishing of the one-loop beta-function.
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The time evolution of the matter produced in high energy heavy-ion collisions seems to be well described by relativistic viscous hydrodynamics. In addition to the hydrodynamic degrees of freedom related to energy-momentum conservation, degrees of freedom associated with order parameters of broken continuous symmetries must be considered because they are all coupled to each other. of particular interest is the coupling of degrees of freedom associated with the chiral symmetry of QCD. Quantum and thermal fluctuations of the chiral fields act as noise sources in the classical equations of motion, turning them into stochastic differential equations in the form of Ginzburg-Landau-Langevin (GLL) equations. Analytic solutions of GLL equations are attainable only in very special circumstances and extensive numerical simulations are necessary, usually by discretizing the equations on a spatial lattice. However, a not much appreciated issue in the numerical simulations of GLL equations is that ultraviolet divergences in the form of lattice-spacing dependence plague the solutions. The divergences are related to the well-known Rayleigh-Jeans catastrophe in classical field theory. In the present communication we present a systematic lattice renormalization method to control the catastrophe. We discuss the implementation of the method for a GLL equation derived in the context of a model for the QCD chiral phase transition and consider the nonequilibrium evolution of the chiral condensate during the hydrodynamic flow of the quark-gluon plasma.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The crystal nucleation rates of a metastable phase (chi) on the surface of a near stoichiometric cordierite glass were determined for temperatures between 839 and 910 degrees C (T-g similar to 800 degrees C). The surface nucleation kinetics of that phase on our glass, as well as on a stoichiometric glass (2 MgO-2Al(2)O(3)-5SiO(2)) studied by other authors, were analysed in terms of the classical nucleation theory; for the first time. It was shown that the effective interfacial energy for surface nucleation is substantially lower than that for homogeneous volume nucleation in silicate glasses, vindicating the assumption of heterogeneous nucleation on free glass surfaces. The average wetting angle between the nucleating crystals and the active solid particles was estimated to be around 46 degrees C. The pre-exponential constant was several orders of magnitude higher than the theoretical values as found for volume homogeneous nucleation in oxide glasses.