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Gerenciamento de projetos em negócios baseados em projetos: uma proposta integrada das dimensões operacional, organizacional e estratégica; Project management in project based businesses: an integrated proposal of the operational, organizational and strategic dimensions

Anselmo, Jefferson Leandro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/12/2009 Português
Relevância na Pesquisa
45.49%
A emergência do gerenciamento de projetos é uma resposta às exigências impostas pelo ambiente empresarial atual. Além de instrumento operacional para a adaptação e evolução organizacional, o gerenciamento de projetos exerce importante papel estratégico, principalmente em empresas cujo negócio tem por base a comercialização de projetos. Os modelos e a literatura sobre as especificidades do gerenciamento de projeto, nesse contexto, são, entretanto, relativamente recentes e pouco extensos. Este estudo colabora com a expansão do conhecimento sobre o tema, propondo, como problema de pesquisa, a identificação das características do gerenciamento de projetos, nas suas dimensões operacional, organizacional e estratégica, em empresas cujo negócio seja baseado em projetos. O estudo, que foi estruturado por meio de casos múltiplos comparados a um referencial bibliográfico, possibilitou a elaboração de considerações sobre a validade da teoria nos casos estudados e sobre necessidades de adaptações que foram evidenciadas. Concluiu-se que a atual teoria de gerenciamento de projetos precisa ser complementada para melhor adequação ao contexto dos negócios baseados em projetos. Essa complementação teórica foi realizada por meio da proposição de um modelo de referência de gerenciamento de projetos...

Modelo e ferramenta para avaliação da agilidade no gerenciamento de projetos; A framework and tool for the project management agility assessment

Conforto, Edivandro Carlos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/03/2013 Português
Relevância na Pesquisa
45.47%
As pesquisas com o objetivo de relacionar o uso de práticas do gerenciamento ágil, desempenho e sucesso do projeto apresentam limitações como baixa qualidade semântica de construtos, dados e instrumentos de coleta com escalas subjetivas e pouco confiáveis, impedindo a verificação da eficácia dessas práticas. Outro problema é a tentativa de relacioná-las diretamente com o desempenho ou sucesso do projeto. Neste trabalho discute-se a hipótese de que a adoção de práticas dessa teoria e o desempenho do projeto não possuem relacionamento direto. Propõe-se a tese de que há um elemento intermediário, denominado neste trabalho de construto agilidade, que pode ser designado como um desempenho. As práticas provenientes da teoria de gerenciamento ágil (ditas ágeis), em conjunto com outros fatores ambientais, contribuiriam para o desempenho em agilidade, e este, por sua vez contribuiria para o desempenho e sucesso do projeto. Considerando esta hipótese, são três os objetivos desta pesquisa: 1) definir agilidade em gerenciamento de projetos; 2) propor um modelo conceitual capaz de explicar a relação entre práticas de gestão de projetos, fatores críticos organizacionais e o desempenho em agilidade, verificando-o; e 3) propor uma ferramenta de diagnóstico da agilidade em gerenciamento de projetos para profissionais...

Projetos de vida e educação moral: um estudo na perspectiva da teoria dos modelos organizadores do pensamento; Life projects and moral education: a study from the perspective of the theory of organizing models of thought

Danza, Hanna Cebel
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/04/2014 Português
Relevância na Pesquisa
55.37%
O presente estudo teve como objetivo investigar os projetos de vida de jovens em idade escolar juntamente com os valores que os subjazem. A relevância do tema se deve à importância dos jovens elaborarem seus projetos de vida orientados por um sentido moral, de modo a buscarem a realização pessoal mediante a atuação no mundo comum. Para esta investigação partimos do conceito de purpose, entendido como um projeto de vida significativo para o próprio jovem, mas que possui implicações para o mundo além dele e de concepções de moral que buscam a compreensão dos processos de integração entre a moralidade e o self. Buscamos na Teoria dos Modelos Organizadores do Pensamento o aporte teórico-metodológico que nos permitiu contemplar a ideia de indissociabilidade entre cognição e afetividade e analisar os dados empíricos sem prescindir da complexidade que emerge de ambas as dimensões. A pesquisa foi realizada com 240 jovens do Ensino Médio em duas escolas da região sul da cidade de São Paulo. A fim de contemplar nossos objetivos, dividimos a pesquisa em duas fases: a primeira, relativa aos projetos de vida dos jovens; a segunda, referente às contribuições que a escola pode ofertar para a elaboração dos projetos de seus alunos. Para o desenvolvimento da primeira fase aplicamos um questionário com os 240 jovens com o intuito de verificar as dinâmicas de pensamento destes sobre seus projetos de vida e os valores que os sustentam. Nesta fase também entrevistamos as diretoras de ambas as escolas sobre suas concepções de moral e projetos de vida. Para o desenvolvimento da segunda fase realizamos uma entrevista semiestruturada com cinco ex-alunos de uma das escolas...

A teoria pulsional freudiana à luz da leitura de Green: uma alternativa ao biologismo mítico; Freuds drive theory in the light of Greens readings: an alternative to mythical biologism

Cano, Tatiana Monreal
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/05/2015 Português
Relevância na Pesquisa
55.34%
Diante da explicação freudiana para o fenômeno da compulsão à repetição através da tese da pulsão de morte concebida enquanto retorno ao estado inorgânico, formula-se a seguinte questão: seria possível, por um lado, recusar a explicação freudiana pautada em seu biologismo mítico e, por outro lado, aceitar a tese de que a pulsão de morte seja uma força de desligamento? Para responder a essa pergunta encontramos um vasto material na obra publicada por André Green ao longo de sua carreira de mais de quarenta anos sob a rubrica trabalho da pulsão de morte, mais tarde, substituída por trabalho do negativo. Este texto tem como objetivo sistematizar a leitura e os aportes de Green à teoria das pulsões freudiana, sobretudo em relação ao segundo dualismo pulsional. Ele se divide em duas partes. Na primeira, destaca-se a análise de Green sobre as relações entre a pulsão de morte e a teoria do narcisismo na obra freudiana; na segunda, sua crítica em relação ao solipsismo freudiano e a necessidade de sua superação através das teorizações contemporâneas em torno às noções de objeto e de espaço potencial. Estas são complementadas por uma teoria da temporalidade do psiquismo. O trabalho defende a tese de que Green aceita o conceito freudiano de pulsão de morte enquanto força de desligamento...

Modos de vida: novos percursos e novos conceitos

Guerra, Isabel
Fonte: CIES-ISCTE / CELTA Publicador: CIES-ISCTE / CELTA
Tipo: Artigo de Revista Científica
Publicado em /03/1993 Português
Relevância na Pesquisa
45.45%
A re-emergência do tema modos de vida recuperando um conceito tradicional na sociologia urbana (e não só) está longe de colocar os mesmos problemas do conceito inicial de Wirth. A sua abrangência, e os questionamentos que encerra são, em si, o maior factor de indefinição desta noção que se tomou um "leitmotiv" sem conteúdo preciso. No entanto, este conceito, ainda hoje confuso, permite interrogar os pressupostos mais essenciais da teoria sociológica. A proposta das análises dos "modos de vida" ao trazer à superfície as velhas questões da teoria sociológica pretende reconciliar, pelo menos, três níveis analíticos ainda pouco articulados: o sistema e os actores, a História e o quotidiano, e o objectivo e o subjectivo na percepção do real. Mas, a utilização deste quadro de referências exige, ainda, a exploração de novas dimensões de análise outrora secundarizadas pela sociologia. À identificação da triologia tradicional da sociologia: "práticas", "estruturas" e "representações" acrescentam-se novas dimensões como o "imaginário social", dimensão prospectiva e de ruptura com o real. Este novo percurso vai exigir a elaboração (ou re-elaboração) de novos conceitos, a maioria "transversais", que se situam na encruzilhada de diversas ciências - o conceito de identidade e de projecto...

Imaging neural correlates of syntactic complexity in a naturalistic context

Bachrach, Asaf
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 280 p.
Português
Relevância na Pesquisa
55.33%
The aim of this thesis, and the research project within which it is embedded, is to delineate a neural model of grammatical competence. For this purpose, we develop here a novel integrated, multi-disciplinary experimental paradigm that endorses the fundamental premise of generative grammar, that the study of language is in essence, the study of the mind. We use functional Magnetic Resonance Imaging (fMRI) to monitor brain activation while subjects listen to short narratives. The texts have been written so as to introduce various syntactic complexities (relative clauses, embedded questions, etc.) not usually found (in such density) in actual corpora. We have calculated a number of complexity measures (both at the level of the single word and at that of the phrase) based on current linguistic and psycholinguistic theory and with the use of a computationally implemented probabilistic parser. By correlating these measures with observed brain activity, we are able to identify the different brain networks that support linguistic processing and characterize their particular function. Conversely, we use the rich brain data to inform our cognitive, and linguistic, theory. We report here the neural correlates of surprisal (based on contextual predictions)...

Encontro clínico no modelo biopsicossocial: autopercepção dos acadêmicos de medicina da Pontifícia Universidade Católica de Goiás; Pacient-physician encounter in biopsychosocial model: selfconcept of medicine students on Pontifical Catholic University of Goiás

CARVALHO, Gélcio Sisteroli de
Fonte: Universidade Federal de Goiás; BR; UFG; Doutorado em Ciencias da Saude; Ciencias da Saude Publicador: Universidade Federal de Goiás; BR; UFG; Doutorado em Ciencias da Saude; Ciencias da Saude
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
45.49%
Introduction: The Pontifical Catholic University of Goiás pedagogical project for its medical course has stemmed from a thirty year long dream. It came into existence in 2005 following the authorization granted by the National Council of Education after the homologation of the National Curricular Guidelines. The present study shows the need to further investigate the development of assessment processes which are used to identify, follow and materialize changes in medical training. The theory used lies on the possibility of quantifying the medical performance in the patient-physician encounter. Objective: to evaluate some components of the patient-physician encounter based on biopsychosocial model; to create an assessment tool to measure the self-perception of this encounter; to test the effectiveness of this tool in this scenario; and to quantify the category variables of the research in a Pontifical Catholic University of Goiás medical course. Materials and Methods: This was a quantitative, longitudinal and cohort study. The study group presented 39 medical students from 5th Class of the Pontifical Catholic University of Goiás Medical School Course and the investigation was divided into two stages with a year interval between the application of the required academic protocols preceded by a medical semiological conclusion. The dimensions under observation were the following: biomedical...

The importance of Complex Product Systems to the space industry in Australia : a small satellite case study

Moody, James Bradfield
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD); Doctor of Philosophy (PhD)
Português
Relevância na Pesquisa
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The great paradox of the space industry in Australia is why, given a strong history of space involvement and a capacity for excellence in space and other complex projects, Australia is unique among developed countries in that it does not have a recognisable space agency and it has little space policy. To try and understand this paradox, this thesis follows the development of the FedSat satellite project, formed in 1998 to ‘re-ignite the Australian Space Industry’. It asks the central question, “Can Australia develop an indigenous satellite industry made up if high-value, complex products?”, framed against the backdrop of innovation, management and policy issues in a multidisciplinary context. The techniques used to analyse the FedSat project draw heavily on the Complex Product System (CoPS) framework, which proposes that high-cost, one-off products have unique innovation, management and policy dimensions and as such, require a different approach to analysis. It is found that CoPS are not only an ideal mechanism for analysing a satellite project, but also a means of placing the space industry within the purview of innovation theory for future comparison with other projects across a range of industry sectors. Within the space industry...

Demixing behavior in two-dimensional mixtures of anisotropic hard bodies

Martínez-Ratón, Yuri; Velasco, Enrique; Mederos, Luis
Fonte: The American Physical Society Publicador: The American Physical Society
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em /09/2005 Português
Relevância na Pesquisa
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Scaled particle theory for a binary mixture of hard discorectangles and for a binary mixture of hard rectangles is used to predict possible liquid-crystal demixing scenarios in two dimensions. Through a bifurcation analysis from the isotropic phase, it is shown that isotropic-nematic demixing is possible in two-dimensional liquid-crystal mixtures composed of hard convex bodies. This bifurcation analysis is tested against exact calculations of the phase diagrams in the framework of the restricted-orientation two-dimensional model (Zwanzig model). Phase diagrams of a binary mixture of hard discorectangles are calculated through the parametrization of the orientational distribution functions. The results show not only isotropic-nematic, but also nematic-nematic demixing ending in a critical point, as well as an isotropic-nematic-nematic triple point for a mixture of hard disks and hard discorectangles.; One of the authors (Y.M.-R.) was supported by a Ramón y Cajal research contract from the Spanish MCyT. This work is part of the research Project Nos. BFM2003-0180, BFM2001-0224-C02-01, BFM2001-0224-C02-02, and BFM2001-1679-C03-02 (DGI) of the Ministerio de Ciencia y Tecnología (Spain).; 11 pages, 9 figures.-- PACS nrs.: 64.70.Md, 64.75.+g...

Improved performance of LDPC-coded MIMO systems with EP-based soft-decisions

Céspedes Martín, Javier; Olmos, Pablo M.; Sánchez-Fernández, Matilde; Pérez-Cruz, Fernando
Fonte: IEEE - The Institute of Electrical and Electronics Engineers, Inc Publicador: IEEE - The Institute of Electrical and Electronics Engineers, Inc
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/bookPart; info:eu-repo/semantics/conferenceObject
Publicado em /06/2014 Português
Relevância na Pesquisa
75.32%
Modern communications systems use efficient encoding schemes, multiple-input multiple-output (MIMO) and high-order QAM constellations for maximizing spectral efficiency. However, as the dimensions of the system grow, the design of efficient and low-complexity MIMO receivers possesses technical challenges. Symbol detection can no longer rely on conventional approaches for posterior probability computation due to complexity. Marginalization of this posterior to obtain per-antenna soft-bit probabilities to be fed to a channel decoder is computationally challenging when realistic signaling is used. In this work, we propose to use Expectation Propagation (EP) algorithm to provide an accurate low-complexity Gaussian approximation to the posterior, easily solving the posterior marginalization problem. EP soft-bit probabilities are used in an LDPC-coded MIMO system, achieving outstanding performance improvement compared to similar approaches in the literature for low-complexity LDPC MIMO decoding.; This work has been partly funded by the Spanish Ministry of Science and Innovation with the projects GRE3NSYST (TEC2011-29006-C03-03) and ALCIT (TEC2012-38800-C03-01) and by the program CONSOLIDERINGENIO 2010 under the project COMONSENS (CSD 2008-00010).; The proceeding at: IEEE International Symposium on Information Theory (ISIT 2014)...

Care in hospital organization: the perspective of the nurses

Santos, Daniela; Pinheiro, Elisabete; Teixeira, Aida; Macedo, Ana Paula
Fonte: International Association for Human Caring Publicador: International Association for Human Caring
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
Relevância na Pesquisa
55.38%
This project takes place at the Hospital de Braga, an university hospital in Portugal, and his end is predicted for December 2016. Some reasons motivate this project: on the one hand, the nursing literature emphasizes that is necessary to research the care and the way it is expressed by nurses. On the other hand, the opportunity arises and it is encouraged by the new Portuguese Development Professional Model in Nursing. One of the required indicators is the existence of a framework which can be enhanced with the support of a philosophy of care associated with the nursing conceptualization. The main objective of this work is to understand the appropriation of care by the nursing professionals, particularly in the behaviors which reflect care, and evolving into an organizational approach to caring because it can influence the care. The guiding questions of this study are: 1) what are the perspectives of nurses about care in the hospital organization? 2) What is the influence of the hospital organization on the nursing care? The used research methodology can be classified mixed because it associated techniques of the qualitative and quantitative ways. First - Collect and interpret the nurse’s perspectives about the care and how they experience it through the use of an open questions survey created by the authors. Second - Identify the dimensions of care valued by nurses through implementation of the “Caring Behaviors Inventory”. Third - Analyze the complexity of integrated care hospital organization...

Visualisierung der Relativitätstheorie - Koordinatenfreie und interaktive Werkzeuge; Visualization of the Theory of Relativity - Coordinate-Free and Interactive Tools

Zahn, Corvin
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
Português
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55.45%
Das Ziel dieser Arbeit ist es, ein intuitives Verständnis der Relativitätstheorie zu gewinnen. Dazu wurden Werkzeuge entwickelt, die es erlauben, einfache Modelle relativistischer Welten mit Hilfe von Methoden unserer alltäglichen Erfahrungswelt wie Betrachten, Betasten oder Begehen zu erforschen. In unserer Erfahrungswelt gibt es keine Koordinatensysteme. Ein wichtiges Ziel war daher, koordinatenfreie Darstellungen interessanter physikalischer Problemstellungen zu entwickeln, wie die (auch interaktive) Visualisierung einer relativistischen Modellwelt aus der Ich-Perspektive, maßstabsgetreue, "anfassbare" 3D-Modelle gekrümmter Räume oder die zeichnerische Darstellung globaler Kausalstrukturen. Die verschiedenen Problemstellungen spiegeln sich in mehreren unabhängigen Projekten wieder. Das verbindendende Element ist die Suche nach einem intuitiven Zugang, was sich in der Koordinatenfreiheit der entwickelten Darstellungen ausdrückt. In dem speziellrelativistischen Visualisierungsprojekt "Rollende Räder" wurde mit einem hierfür entwickelten vierdimensionalen Raytracingprogramm untersucht, wie ein fast lichtschnell rollendes Rad inklusive Schattenwurf relativistisch korrekt aussieht. Für den "Relativistischen Flugsimulator" wurde basierend auf der Modellierung der Raumzeit mit dem Regge-Calculus ein neuartiges schnelles Real-Time Raytracing-Verfahren für gekrümmte Raumzeiten entwickelt. Das dimensionsunabhängige Verfahren ist allgemein gehalten und kann prinzipiell mit beliebigen Raumzeiten eingesetzt werden. In diesem Projekt wurde es in einem interaktiven Flugsimulator angewandt...

Les dimensions négligées de l'évaluation de la performance : les valeurs et la qualité de vie au travail

Thiebaut, Georges-Charles
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
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45.45%
L’objet de cette thèse est l’élaboration d’un modèle logique de mesure du maintien des valeurs, ainsi que son opérationnalisation afin d’entreprendre l’évaluation de la performance des systèmes de santé. Le maintien des valeurs est l’une des quatre fonctions de la théorie de l’action sociale de T.Parsons permettant d’analyser les systèmes d’action. Les autres fonctions sont l’adaptation, la production et l’atteinte des buts. Cette théorie est la base du modèle EGIPSS (évaluation globale et intégrée de la performance des systèmes de santé), dans lequel cette thèse s’insère. La fonction étudiée correspond, dans l’oeuvre de T.Parsons, au sous-système culturel. Elle renvoie à l’intangible, soit à l’univers symbolique par lequel l’action prend son sens et les fonctions du système s’articulent. Le modèle logique de mesure du maintien des valeurs est structuré autour de deux concepts principaux, les valeurs individuelles et organisationnelles et la qualité de vie au travail. À travers les valeurs individuelles et organisationnelles, nous mesurons la hiérarchie et l’intensité des valeurs, ainsi que le niveau de concordance interindividuelle et le degré de congruence entre les valeurs individuelles et organisationnelles. La qualité de vie au travail est composée de plusieurs concepts permettant d’analyser et d’évaluer l’environnement de travail...

Design thinking and the precautionary principle : development of a theoretical model complementing preventive judgment for design for sustainability enriched through a study of architectural competitions adopting LEED

Cucuzzella, Carmela
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
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55.39%
Cette thèse contribue à une théorie générale de la conception du projet. S’inscrivant dans une demande marquée par les enjeux du développement durable, l’objectif principal de cette recherche est la contribution d’un modèle théorique de la conception permettant de mieux situer l’utilisation des outils et des normes d’évaluation de la durabilité d’un projet. Les principes fondamentaux de ces instruments normatifs sont analysés selon quatre dimensions : ontologique, méthodologique, épistémologique et téléologique. Les indicateurs de certains effets contre-productifs reliés, en particulier, à la mise en compte de ces normes confirment la nécessité d’une théorie du jugement qualitatif. Notre hypothèse principale prend appui sur le cadre conceptuel offert par la notion de « principe de précaution » dont les premières formulations remontent du début des années 1970, et qui avaient précisément pour objectif de remédier aux défaillances des outils et méthodes d’évaluation scientifique traditionnelles. La thèse est divisée en cinq parties. Commençant par une revue historique des modèles classiques des théories de la conception (design thinking) elle se concentre sur l’évolution des modalités de prise en compte de la durabilité. Dans cette perspective...

On Discrete Physics: a Perfect Deterministic Structure for Reality - And "The Mathematical Derivation of the Laws of the Fundamental Forces of Nature"

Zahedi, Ramin
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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In part I (pp. 1-10) of this article, I provide an analysis and overview of some notable definitions, works and thoughts concerning discrete physics (a.k.a. digital philosophy, digital physics or digital cosmology) that propose finite, discrete and deterministic characteristics for the physical world. Particular attention is given to theories which suggest cellular automata, as the basis of a (or the only) perfect mathematical deterministic model for the physical reality. In part II (the main part, pp.11-104, Ref. [37]) of this article, I've presented a new algebraic matrix approach based on the theory of Rings (including the Integral Domains). On the basis of this approach, by linearization (and simultaneous parameterization) followed by quantization of the relativistic energy-momentum relation, a unique set of tensor field equations are derived. These tensor equations are shown to correspond to the general forms of equations of motion of all the fundamental fields of physics, including the laws of the fundamental forces of nature (i.e. gravitational, electromagnetic and nuclear field equations), the relativistic particle wave-equations, and their generalizations. Notably, this result is primarily mathematical, assuming the relativistic energy-momentum is discrete (that is a basic and primary quantum mechanical assumption). In particular...

The Adapted Ordering Method for Lie algebras and superalgebras and their generalizations

Gato Rivera, Beatriz
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artículo Formato: 175838 bytes; application/pdf
Português
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65.33%
11 pages, 2 tables.-- PACS numbers: 02.20.Qs, 02.20.Tw.-- ArXiv pre-print available at: http://arxiv.org/abs/0706.2859; In 1998 the Adapted Ordering Method was developed for the representation theory of the superconformal algebras in two dimensions. It allows us to determine maximal dimensions for a given type of space of singular vectors, to identify all singular vectors by only a few coefficients, to spot subsingular vectors and to set the basis for constructing embedding diagrams. In this paper we present the Adapted Ordering Method for general Lie algebras and superalgebras and their generalizations, provided they can be triangulated. We also review briefly the results obtained for the Virasoro algebra and for the N = 2 and Ramond N = 1 superconformal algebras.; The work of the author is partially supported by funding of the Spanish Ministerio de Educación y Ciencia, Research Project FPA2005-05046.; Peer reviewed

Discrete solitons and vortices in the two-dimensional Salerno model with competing nonlinearities

Gómez-Gardeñes, Jesús; Malomed, B. A.; Floría, Luis Mario; Bishop, A. R.
Fonte: American Physical Society Publicador: American Physical Society
Tipo: Artículo Formato: 1192871 bytes; application/pdf
Português
Relevância na Pesquisa
55.29%
10 pages, 11 figures.-- PACS number(s): 05.45.Yv, 63.20.Ry, 03.75.Lm; An anisotropic lattice model in two spatial dimensions, with on-site and intersite cubic nonlinearities (the Salerno model), is introduced, with emphasis on the case in which the intersite nonlinearity is self-defocusing, competing with on-site self-focusing. The model applies, for example, to a dipolar Bose-Einstein condensate trapped in a deep two-dimensional (2D) optical lattice. Soliton families of two kinds are found in the model: ordinary ones and cuspons, with peakons at the border between them. Stability borders for the ordinary solitons are found, while all cuspons (and peakons) are stable. The Vakhitov-Kolokolov criterion does not apply to cuspons, but for the ordinary solitons it correctly identifies the stability limits. In direct simulations, unstable solitons evolve into localized pulsons. Varying the anisotropy parameter, we trace a transition between the solitons in 1D and 2D versions of the model. In the isotropic model, we also construct discrete vortices of two types, on-site and intersite centered (vortex crosses and squares, respectively), and identify their stability regions. In simulations, unstable vortices in the noncompeting model transform into regular solitons...

Theory of neutrinos: a white paper

Mohapatra, R. N.; Antusch, S.; Babu, K. S.; Barenboim, Gabriela; Chen, M. C.; De Gouvea, A.; De Holanda, P.; Dutta, B.; Grossman, Y.; Joshipura, A.; Kayser, B.; Kersten, J.; Keum, Y. Y.; King, S. F.; Langacker, P.; Lindner, M.; Loinaz, W.; Masina, I.; Moc
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artículo Formato: 2373 bytes; text/plain
Português
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111 pages, 23 figures.-- ISI Article Identifier: 000250727500002.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ph/0510213; Printed version published in Nov 2007.; This paper is a review of the present status of neutrino mass physics, which grew out of an APS sponsored study of neutrinos in 2004. After a discussion of the present knowledge of neutrino masses and mixing and some popular ways to probe the new physics implied by recent data, it summarizes what can be learned about neutrino interactions as well as the nature of new physics beyond the Standard Model from the various proposed neutrino experiments. The intriguing possibility that neutrino mass physics may be at the heart of our understanding of a long standing puzzle of cosmology, i.e. the origin of matter-antimatter asymmetry is also discussed.; The work of RNM is supported by the National Science Foundation grant no. PHY-0099544 and PHY-0354401. The work of WR and ML is supported by the ‘Deutsche Forschungsgemeinschaft’ in the ‘Sonderforschungsbereich 375 für Astroteilchenphysik’ and under project number RO–2516/3–1 (WR). The work of MR is partially supported by the EU 6th Framework Program MRTN-CT-2004-503369 ‘Quest for Unification’ and MRTNCT-2004-005104 ‘ForcesUniverse’. The work of RS is supported in part by the NSF grant NSF-PHY-03-54776. The work of JK is supported by the ‘Impuls- und Vernetzungsfonds’ of the Helmholtz Assciation...

Quantum Gowdy T3 model: a uniqueness result

Corichi, Alejandro; Cortez, Jerónimo; Mena Marugán, Guillermo A.; Velhinho, José M.
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artículo Formato: 248754 bytes; application/pdf
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19 pags. ; appendix; Modulo a homogeneous degree of freedom and a global constraint, the linearly polarized Gowdy T3 cosmologies are equivalent to a free scalar field propagating in a fixed nonstationary background. Recently, a new field parametrization was proposed for the metric of the Gowdy spacetimes such that the associated scalar field evolves in a flat background in (1+1) dimensions with the spatial topology of S1, although subject to a time-dependent potential. Introducing a suitable Fock quantization for this scalar field, a quantum theory was constructed for the Gowdy model in which the dynamics is implemented as a unitary transformation. A question that was left open is whether one might adopt a different, nonequivalent Fock representation by selecting a distinct complex structure. The present work proves that the chosen Fock quantization is in fact unique (up to unitary equivalence) if one demands unitary implementation of the dynamics and invariance under the group of S1 translations. These translations are precisely those generated by the global constraint that remains on the Gowdy model. It is also shown that the proof of uniqueness in the choice of the complex structure can be applied to more general field dynamics than that corresponding to the Gowdy cosmologies.; The authors are greatly thankful to A Ashtekar for enlightening conversations and suggestions. Thisworkwas supported by the joint Spanish–Portuguese Project HP03-140...

A Test Of Culture Opposition's Power Grid

Aguirre, Benigno E.
Fonte: Disaster Research Center Publicador: Disaster Research Center
Tipo: Outros Formato: 1557591 bytes; application/pdf
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The paper uses culture of opposition theory to identify ten attributes of cultures of opposition (CO) in state polities. It then uses these general attributes of CO to construct a measure of knowledge of the culture of opposition (CO) and of a set of covariates using information from Cuba. Six theoretically derived dimensions are used to group the sixteen covariates included in the OLS models. They are oppositional politics, respondents' perceptions and activities in relation to the dissidence in the island, the use of mass media, integration with state, evaluation of life in Cuba, and the economic situation of the respondents. OLS is used to model the experiences of 1023 Cuban immigrants who participated in the recently completed survey "Measuring Cuban Opinion Project." Six hypotheses are tested. The results support most of the predictions. Knowledge of the culture of opposition is: a.positively associated with the extent to which respondents feel repressed by the state and with their tendency to perceive people to be opposed to the government's repressive tactics; b. is positively associated with the extent to which respondents develop dissidents' self-conceptions, participate in dissident organizations, and perceive people as respecting the dissidents; c. negatively correlated with lack of access to news from abroad; d. negatively associated with membership in state organizations prior to emigrating from Cuba; e. positively associated with hatred of the leaders and organization of the Cuban state and if respondents thought that there had not been advances in public health and education. Contrary to the prediction...