964 resultados para Two dimensions


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L'activitat professional és fonamental en la vida de qualsevol persona i en el cas de les persones amb discapacitat resulta molt potent per tal que assumeixin la identitat adulta. Per això, en la tesi es realitza una aproximació al binomi discapacitat i treball i a les mesures que justifiquen l'actual situació de la inserció laboral de les persones amb discapacitat al mercat laboral protegit i al mercat laboral ordinari. L'objectiu general de la tesi és conèixer en profunditat una experiència d'inserció laboral de persones amb discapacitat psíquica a l'Administració de la Generalitat de Catalunya. La investigació realitzada s'ha estructurat en dues fases. En la primera fase s'ha fet una anàlisi descriptiva del col·lectiu estudiat i en la segona fase, emmarcada en una perspectiva metodològica qualitativa, s'ha desenvolupat un estudi de casos per tal de mostrar el testimoni dels protagonistes, partir del seu relat i recollir les seves valoracions.

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For a nonlocally perturbed half- space we consider the scattering of time-harmonic acoustic waves. A second kind boundary integral equation formulation is proposed for the sound-soft case, based on a standard ansatz as a combined single-and double-layer potential but replacing the usual fundamental solution of the Helmholtz equation with an appropriate half- space Green's function. Due to the unboundedness of the surface, the integral operators are noncompact. In contrast to the two-dimensional case, the integral operators are also strongly singular, due to the slow decay at infinity of the fundamental solution of the three-dimensional Helmholtz equation. In the case when the surface is sufficiently smooth ( Lyapunov) we show that the integral operators are nevertheless bounded as operators on L-2(Gamma) and on L-2(Gamma G) boolean AND BC(Gamma) and that the operators depend continuously in norm on the wave number and on G. We further show that for mild roughness, i.e., a surface G which does not differ too much from a plane, the boundary integral equation is uniquely solvable in the space L-2(Gamma) boolean AND BC(Gamma) and the scattering problem has a unique solution which satisfies a limiting absorption principle in the case of real wave number.

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Slantwise convective available potential energy (SCAPE) is a measure of the degree to which the atmosphere is unstable to conditional symmetric instability (CSI). It has, until now, been defined by parcel theory in which the atmosphere is assumed to be nonevolving and balanced, that is, two-dimensional. When applying this two-dimensional theory to three-dimensional evolving flows, these assumptions can be interpreted as an implicit assumption that a timescale separation exists between a relatively rapid timescale for slantwise ascent and a slower timescale for the development of the system. An approximate extension of parcel theory to three dimensions is derived and it is shown that calculations of SCAPE based on the assumption of relatively rapid slantwise ascent can be qualitatively in error. For a case study example of a developing extratropical cyclone, SCAPE calculated along trajectories determined without assuming the existence of the timescale separation show large SCAPE values for parcels ascending from the warm sector and along the warm front. These parcels ascend into the cloud head within which there is some evidence consistent with the release of CSI from observational and model cross sections. This region of high SCAPE was not found for calculations along the relatively rapidly ascending trajectories determined by assuming the existence of the timescale separation.

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The X-ray crystal structure of the 1:2 condensate (1) of hydrazine hydrate and 4-methyl-imidazole-5-carboxaldehyde has been determined. The molecule is centrosymmetric crystallising in the space group Fddd with cell dimensions: a = 10.557(14), b = 17.062(22), c = 24.759(27) angstrom. Fourier map shows that the NH hydrogen atom of each imidazole moiety has equal possibility of occupying any of its two ring N atoms. This poses the possibility of finding three tautomers in 1 in the solid state. Consideration of the H-bonding pattern observed in 1 and related B3LYP/6-311+G(2d, p) calculations show that only two tautomers are present in the solid state. The situation is compared with that in the structure of 4(5)-nitro-5(4)-methoxy-imidazole reported previously by Kubicki.

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Whereas several clinical endpoints in monitoring the response to treatment in patients with Huntington's disease (HD) have been explored, there has been a paucity of research in the quality of life in such patients. The aim of this study was to validate the use of two generic health-related quality of life instruments (the Short Form 36 health survey questionnaire [SF-36] and the Sickness Impact Profile [SIP]) and to evaluate their psychometric properties. We found that both instruments demonstrated acceptable convergent validity and reliability for patients and carers. However, there was an advantage in using the SF-36 because of its more robust construct validity and test-retest reliability; furthermore, motor symptoms appeared to influence some strictly nonmotor dimensions of the SIP. On a pragmatic level, the SF-36 is shorter and quicker to administer and, therefore, easier for patients at various stages of the disease to complete. Thus, the SF-36 would appear to be the recommended instrument of choice for patients with HD and their carers, although further work needs to be done to investigate the sensitivity of this instrument longitudinally. (C) 2004 Movement Disorder Society.

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Recent research shows that because they rely on separate goals, cognitions about not performing a behaviour are not simple opposites of cognitions about performing the same behaviour. Using this perspective, two studies (N = 758 & N = 104) examined the psycho-social determinants of reduction in resource consumption. Results showed that goals associated with reducing versus not reducing resource consumption were not simple opposites (Study 1). Additionally, the discriminant validity of the Theory of Planned Behaviour constructs associated with reducing versus not reducing resource consumption was demonstrated (Study 1 & 2). Moreover, results revealed the incremental validity of both Intentions (to reduce and to not reduce resource consumption) for predicting a series of behaviours (Study 1 & 2). Finally, results indicated a mediation role for the importance of ecological dimensions on the effect of both Intentions on a mock TV choice and a mediation role for the importance of non ecological dimensions on the effect of Intention of not reducing on the same TV choice. Discussion is organized around the consequences, at both theoretical and applied levels, of considering separate motivational systems for reducing and not reducing resource consumption.

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For more than half a century, emotion researchers have attempted to establish the dimensional space that most economically accounts for similarities and differences in emotional experience. Today, many researchers focus exclusively on two-dimensional models involving valence and arousal. Adopting a theoretically based approach, we show for three languages that four dimensions are needed to satisfactorily represent similarities and differences in the meaning of emotion words. In order of importance, these dimensions are evaluation-pleasantness, potency-control, activation-arousal, and unpredictability. They were identified on the basis of the applicability of 144 features representing the six components of emotions: (a) appraisals of events, (b) psychophysiological changes, (c) motor expressions, (d) action tendencies, (e) subjective experiences, and (f) emotion regulation.

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Aim: The aim of this randomized, controlled, clinical study was to compare two surgical techniques with the acellular dermal matrix graft (ADMG) to evaluate which technique could provide better root coverage. Material and Methods: Fifteen patients with bilateral Miller Class I gingival recession areas were selected. In each patient, one recession area was randomly assigned to the control group, while the contra-lateral recession area was assigned to the test group. The ADMG was used in both groups. The control group was treated with a broader flap and vertical-releasing incisions, and the test group was treated with the proposed surgical technique, without releasing incisions. The clinical parameters evaluated before the surgeries and after 12 months were: gingival recession height, probing depth, relative clinical attachment level and the width and thickness of keratinized tissue. Results: There were no statistically significant differences between the groups for all parameters at baseline. After 12 months, there was a statistically significant reduction in recession height in both groups, and there was no statistically significant difference between the techniques with regard to root coverage. Conclusions: Both surgical techniques provided significant reduction in gingival recession height after 12 months, and similar results in relation to root coverage.

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Objective: To study the growth of children with complete unilateral cleft lip and palate (UCLP) from birth to 2 years of age and to construct specific UCLP growth curves. Design: Physical growth was a secondary outcome measure of a National Institutes of Health-sponsored longitudinal, prospective clinical trial involving the University of Florida (United States) and the University of Sao Paulo (Brazil). Patients: Six hundred twenty-seven children with UCLP, nonsyndromic, both genders. Methods: Length, weight, and head circumference were prospectively measured for a group of children enrolled in a clinical trial. Median growth curves for the three parameters (length, weight, head circumference) were performed and compared with the median for the National Center for Health Statistics (NCHS) curves. The median values for length, weight, and head circumference at birth and 6, 12, 18, and 24 months of age were plotted against NCHS median values and statistically compared at birth and 24 months. Setting: Hospital de Reabilitacao de Anomalias Craniofaciais, Universidade de Sao Paulo, Bauru, Brazil (HRAC-USP). Results: At birth, children of both genders with UCLP presented with smaller body dimensions in relation to NCHS median values, but the results suggest a catch-up growth for length, weight, and head circumference for girls and for weight (to some degree) and head circumference for boys. Conclusions: Weight was the most compromised parameter for both genders, followed by length and then head circumference. There was no evidence of short stature. This study established growth curves for children with UCLP.

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We present a detailed description of the Voronoi Tessellation (VT) cluster finder algorithm in 2+1 dimensions, which improves on past implementations of this technique. The need for cluster finder algorithms able to produce reliable cluster catalogs up to redshift 1 or beyond and down to 10(13.5) solar masses is paramount especially in light of upcoming surveys aiming at cosmological constraints from galaxy cluster number counts. We build the VT in photometric redshift shells and use the two-point correlation function of the galaxies in the field to both determine the density threshold for detection of cluster candidates and to establish their significance. This allows us to detect clusters in a self-consistent way without any assumptions about their astrophysical properties. We apply the VT to mock catalogs which extend to redshift 1.4 reproducing the ACDM cosmology and the clustering properties observed in the Sloan Digital Sky Survey data. An objective estimate of the cluster selection function in terms of the completeness and purity as a function of mass and redshift is as important as having a reliable cluster finder. We measure these quantities by matching the VT cluster catalog with the mock truth table. We show that the VT can produce a cluster catalog with completeness and purity > 80% for the redshift range up to similar to 1 and mass range down to similar to 10(13.5) solar masses.

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We develop the superfield approach to the effective potential in three dimensions and calculate the one-loop and two-loop Kahlerian effective potential in commutative and noncommutative cases. (C) 2009 Published by Elsevier B.V.

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The count intercept is a robust method for the numerical analysis of fabrics Launeau and Robin (1996). It counts the number of intersections between a set of parallel scan lines and a mineral phase, which must be identified on a digital image. However, the method is only sensitive to boundaries and therefore supposes the user has some knowledge about their significance. The aim of this paper is to show that a proper grey level detection of boundaries along scan lines is sufficient to calculate the two-dimensional anisotropy of grain or crystal distributions without any particular image processing. Populations of grains and crystals usually display elliptical anisotropies in rocks. When confirmed by the intercept analysis, a combination of a minimum of 3 mean length intercept roses, taken on 3 more or less perpendicular sections, allows the calculation of 3-dimensional ellipsoids and the determination of their standard deviation with direction and intensity in 3 dimensions as well. The feasibility of this quick method is attested by numerous examples on theoretical objects deformed by active and passive deformation, on BSE images of synthetic magma flow, on drawing or direct analysis of thin section pictures of sandstones and on digital images of granites directly taken and measured in the field. (C) 2010 Elsevier B.V. All rights reserved.

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We investigate several two-dimensional guillotine cutting stock problems and their variants in which orthogonal rotations are allowed. We first present two dynamic programming based algorithms for the Rectangular Knapsack (RK) problem and its variants in which the patterns must be staged. The first algorithm solves the recurrence formula proposed by Beasley; the second algorithm - for staged patterns - also uses a recurrence formula. We show that if the items are not so small compared to the dimensions of the bin, then these algorithms require polynomial time. Using these algorithms we solved all instances of the RK problem found at the OR-LIBRARY, including one for which no optimal solution was known. We also consider the Two-dimensional Cutting Stock problem. We present a column generation based algorithm for this problem that uses the first algorithm above mentioned to generate the columns. We propose two strategies to tackle the residual instances. We also investigate a variant of this problem where the bins have different sizes. At last, we study the Two-dimensional Strip Packing problem. We also present a column generation based algorithm for this problem that uses the second algorithm above mentioned where staged patterns are imposed. In this case we solve instances for two-, three- and four-staged patterns. We report on some computational experiments with the various algorithms we propose in this paper. The results indicate that these algorithms seem to be suitable for solving real-world instances. We give a detailed description (a pseudo-code) of all the algorithms presented here, so that the reader may easily implement these algorithms. (c) 2007 Elsevier B.V. All rights reserved.

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We examine bivariate extensions of Aït-Sahalia’s approach to the estimation of univariate diffusions. Our message is that extending his idea to a bivariate setting is not straightforward. In higher dimensions, as opposed to the univariate case, the elements of the Itô and Fokker-Planck representations do not coincide; and, even imposing sensible assumptions on the marginal drifts and volatilities is not sufficient to obtain direct generalisations. We develop exploratory estimation and testing procedures, by parametrizing the drifts of both component processes and setting restrictions on the terms of either the Itô or the Fokker-Planck covariance matrices. This may lead to highly nonlinear ordinary differential equations, where the definition of boundary conditions is crucial. For the methods developed, the Fokker-Planck representation seems more tractable than the Itô’s. Questions for further research include the design of regularity conditions on the time series dependence in the data, the kernels actually used and the bandwidths, to obtain asymptotic properties for the estimators proposed. A particular case seems promising: “causal bivariate models” in which only one of the diffusions contributes to the volatility of the other. Hedging strategies which estimate separately the univariate diffusions at stake may thus be improved.

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Apesar da pesquisa em confiança interorganizacional e sua relação com performance ter sido conduzida sob as perspectivas da Teoria de Custos de Transação, Teoria das Trocas Sociais e Canais de Marketing, três importantes lacunas na literatura requerem investigação. Primeiro, está em andamento um debate conceitual sobre a multi-dimensionalidade da confiança, e como ela deve ser operacionalizada e medida, e que se divide em três correntes de pensamento - um construto multidimensional definido por dimensões não dominantes, um construto baseado em duas dimensões dominantes (afetiva e calculativa), ou um construto unidimensional. Segundo, existe ambiguidade em como as dimensões da confiança são definidas, levando a artefatos de equivalência nas escalas e resultados contraditórios. Terceiro, as diferentes percepções que compradores e fornecedores podem ter em cada dimensão da confiança e seu impacto na performance logística ainda não estão claros. Esta pesquisa empírica examina a confiança nas relações entre compradores e fornecedores no setor de logística no Brasil, através de duas amostras e estudos independentes: um examina a percepção dos compradores e o outro examina a dos fornecedores. Em seguida, os dois estudos são comparados para determinar as diferentes perspectivas da confiança e as implicações na performance logística. A análise multivariada mostrou que a confiança parece estar presente nas relações interorganizacionais, e é a percepção do comprador que possui maior relação com a performance logística. Ao mesmo tempo, compradores percebem fornecedores de forma mais negativa nas dimensões mensuráveis (competência e performance), enquanto não foram encontradas diferenças nos aspectos sociais (honestidade e benevolência), o que pode ser resultado do ambiente e cultura pesquisados. As análises mostraram que, apesar da confiança poder ser definida como um construto multidimensional, ela deve ser operacionalizada como um construto unidimensional direcionado pela competência e credibilidade. Este estudo contribui para a prática sugerindo formas de aumentar a confiança interorganizacional para aumento da performance.