982 resultados para Gap model


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While the simulation of flood risks originating from the overtopping of river banks is well covered within continuously evaluated programs to improve flood protection measures, flash flooding is not. Flash floods are triggered by short, local thunderstorm cells with high precipitation intensities. Small catchments have short response times and flow paths and convective thunder cells may result in potential flooding of endangered settlements. Assessing local flooding and pathways of flood requires a detailed hydraulic simulation of the surface runoff. Hydrological models usually do not incorporate surface runoff at this detailedness but rather empirical equations are applied for runoff detention. In return 2D hydrodynamic models usually do not allow distributed rainfall as input nor are any types of soil/surface interaction implemented as in hydrological models. Considering several cases of local flash flooding during the last years the issue emerged for practical reasons but as well as research topics to closing the model gap between distributed rainfall and distributed runoff formation. Therefore, a 2D hydrodynamic model, depth-averaged flow equations using the finite volume discretization, was extended to accept direct rainfall enabling to simulate the associated runoff formation. The model itself is used as numerical engine, rainfall is introduced via the modification of waterlevels at fixed time intervals. The paper not only deals with the general application of the software, but intends to test the numerical stability and reliability of simulation results. The performed tests are made using different artificial as well as measured rainfall series as input. Key parameters of the simulation such as losses, roughness or time intervals for water level manipulations are tested regarding their impact on the stability.

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Ao analisar o grande esforço e tempo dedicado ao planejamento da estratégia corporativa, nota-se que muitas empresas não apresentam resultados coerentes com a dedicação empregada. Um estudo realizado pela consultoria Marakon Associates (2004), sugere que, na média, apenas 60% dos resultados financeiros da empresa derivam do plano estratégico. O presente trabalho foca principalmente em incorporar a estratégia, refletida no mapa estratégico do balanced scorecard, às atividades e projetos da empresa, a fim de que sejam alcançados os resultados almejados. O objetivo é avaliar o modelo proposto, priorizando e balanceando os projetos de acordo com a estratégia planejada. Com isto, podese minimizar o gap entre a formulação e a execução da estratégia, para tanto, o modelo é composto de vários processos e métodos de avaliação, utilizando teorias relacionadas à estratégia e gestão de portfólio como referência. No presente trabalho, este modelo foi aplicado em uma empresa de telecomunicações situada no Brasil (para assegurar confidencialidade a empresa será tratada como "empresa X"). Porém, este modelo também poderá ser aplicado em empresas com características similares, desde que sejam efetuadas as customizações devidas. O ponto forte deste modelo é que engloba todas as dimensões da estratégia corporativa, tais quais, evolução organizacional, clientes e processos internos, e não somente a perspectiva financeira, como na maioria dos outros modelos. Por outro lado, o ponto fraco do modelo é a dependência em relação à qualidade da informação recebida para efetuar a análise, priorização e balanceamento do portfólio de projetos. Devido a esta característica inerente ao modelo, algumas metas de indicadores do balanced scorecard apresentaram diferenças em relação ao valor realizado. Conclui-se, com a utilização do modelo proposto, que os resultados obtidos são bem consistentes e alinhados com o plano estratégico do balanced scorecard.

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It is well documented venture capital‟s positive impact on creation and development of highly successful innovative companies worldwide. Venture capital not only provides funding to startups and SMEs (small and medium enterprises) that usually have financing gap, especially in emerging markets, but also brings a whole package of valuable resources that reduces companies‟ mortality rates. Using quantitative data obtained from an empirical survey as background, this paper discusses the role of venture capital in the success of innovative startups and SMEs, and it examines if, and to what extent, venture capitalists are supporting the entrepreneurial activity in Brazil. I focused on the portfolio companies analyzes and confirmed the hypothesis that the venture capital industry has been supporting entrepreneurship in Brazil. Second, I identified an important evidence of a venture capital‟s positive impact on economic activity, especially the capital market. Third, it became clear that venture capital-back entrepreneurship is highly concentrated in the Southeast region. And fourth, I identified that private equity expansion is also playing a key role on that dynamics. As consequence, I conclude that the venture capital (and private equity) industry has been very important to build an enormously dynamic and strong local entrepreneurial economy. Its committed capital grew 50% per year between 2005 and 2008 to achieve US$27 billion, which invested US$ 11 billion, which employs 1,400 professionals (75% with post-graduate degrees) and maintains 482 portfolio companies, mostly SMEs. In addition, venture capital-backed companies represented one third of the IPOs that occurred in Brazil between 2004 and 2008 (approximately US$15 billion).

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The Knowledge Management in organizations is a continuous process of learning that is given by the integration of data, information and the ability of people to use this information. The Management Skills is concerned to understand the powers of officials in the face of organizational skills (teams) and professionals (or tasks positions) want. Joints are located in the greater context of the economy of organizatio s and have the same assumption: that the possession of scarce resources, valuable and difficult to imitate gives the organization a competitive advantage. In this sense, this thesis proposes a model of knowledge management based on analysis of GAP of powers, namely the gap between the skills needed to reach the expected performance and skills already available in the organization, officials and trainees of Coordination of Registration of conductors of DETRAN-RN. Using the method of survey research could make an analysis of academic skills, techniques and emotional individual and a team of officials and trainees, identifying levels of GAP's competence in that sector of the organization and suggest a plan for training , A level of expertise for each sector of coordination, and propose a model for Knowledge Management to help the management of GAP's identified

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Within the framework of the mean-field hydrodynamic model of a degenerate Fermi gas ( DFG), we study, by means of numerical methods and variational approximation ( VA), the formation of fundamental gap solitons ( FGSs) in a DFG ( or in a BCS superfluid generated by weak interaction between spin- up and spin- down fermions), which is trapped in a periodic optical- lattice ( OL) potential. An effectively one- dimensional ( 1D) con. guration is considered, assuming strong transverse confinement; in parallel, a proper 1D model of the DFG ( which amounts to the known quintic equation for the Tonks- Girardeau gas in the OL) is considered too. The FGSs found in the first two bandgaps of the OL- induced spectrum ( unless they are very close to edges of the gaps) feature a ( tightly bound) shape, being essentially confined to a single cell of the OL. In the second bandgap, we also find antisymmetric tightly bound subfundamental solitons ( SFSs), with zero at the midpoint. The SFSs are also confined to a single cell of the OL, but, unlike the FGSs, they are unstable. The predicted solitons, consisting of similar to 10(4) - 10(5) atoms, can be created by available experimental techniques in the DFG of Li-6 atoms.

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We propose an approach which allows one to construct and use a potential function written in terms of an angle variable to describe interacting spin systems. We show how this can be implemented in the Lipkin-Meshkov-Glick, here considered a paradigmatic spin model. It is shown how some features of the energy gap can be interpreted in terms of a spin tunneling. A discrete Wigner function is constructed for a symmetric combination of two states of the model and its time evolution is obtained. The physical information extracted from that function reinforces our description of phase oscillations in a potential. (c) 2004 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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We consider a dynamical model of a superfluid Fermi gas in the Bardeen-Cooper-Schrieffer regime trapped in a periodic optical lattice (OL) potential. The model is based on an equation for complex order parameter phi of the superfluid, which is derived from the relevant energy density and includes a self-repulsive term similar to phi(7/3). By means of the variational approximation (VA) and numerical simulations, we find families of stable one- and two-dimensional (I D and 2D) gap solitons (GSs) in this model. Chiefly, they are compact objects trapped in a single cell of the OL. Families of stable even and odd bound states of these GSs are also found in one dimension. A 3D GS family is constructed too, but solely within the framework of the VA. In the linear limit, the VA predicts an almost exact position of the left edge of the first band-gap in the OL-induced spectrum. The full VA provides an accurate description of families of I D and 2D fundamental GSs. We also demonstrate that a I D GS can be safely transported by an OL moving at a moderate velocity. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved.

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An integrable asymmetric exclusion process with impurities is formulated. The model displays the full spectrum of the stochastic asymmetric XXZ chain plus new levels. We derive the Bethe equations and calculate the spectral gap for the totally asymmetric diffusion at half filling. While the standard asymmetric exclusion process without impurities belongs to the KPZ universality class with an exponent 3/2, our model has a scaling exponent 5/3.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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We study the (D) over barN interaction at low energies with a quark model inspired in the QCD Hamiltonian in Coulomb gauge. The model Hamiltonian incorporates a confining Coulomb potential extracted from a self-consistent quasiparticle method for the gluon degrees of freedom, and transverse-gluon hyperfine interaction consistent with a finite gluon propagator in the infrared. Initially a constituent-quark mass function is obtained by solving a gap equation and baryon and meson bound-states are obtained in Fock space using a variational calculation. Next, having obtained the constituent-quark masses and the hadron waves functions, an effective meson-nucleon interaction is derived from a quark-interchange mechanism. This leads to a short range meson-baryon interaction and to describe long-distance physics vector- and scalar-meson exchanges described by effective Lagrangians are incorporated. The derived effective (D) over barN potential is used in a Lippmann-Schwinger equation to obtain phase shifts. The results are compared with a recent similar calculation using the nonrelativistic quark model.

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We propose a two band model for superconductivity. It turns out that the simplest nontrivial case considers solely interband scattering, and both bands can be modeled as symmetric (around the Fermi level) and flat, thus each band is completely characterized by its half-band width Wn (n=1,2). A useful dimensionless parameter is d, proportional to W2 - W1. The case delta = 0 retrieves the conventional BCS model. We probe the specific heat, the ratio gap over critical temperature, the thermodynamic critical field and tunneling conductance as functions of d and temperature (from zero to Tc). We compare our results with experimental results for MgB2 and good quantitative agreement is obtained, indicating the relevance of interband coupling. Work in progress also considers the inclusion of band hybridization and general interband as well as intra-band scattering mechanisms.

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Supersymmetry is already observed in (i) nuclear physics where the same empirical formula based on a graded Lie group described even-even and odd-even nuclear spectra and (ii) in Nambu-BCS theory where there is a simple relationship between the energy gap of the basic fermion and the bosonic collective modes. We now suggest similar relationships between the large number of mesonic and baryonic excitations based on the SU(3) substructure in the U(15/30) graded Lie group.

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Includes bibliography

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Purpose: The aim of this work is to address the issue of environmental training in organizations, presenting a theoretical review on the subject and proposing a model that highlights the importance of this type of training for organizations. Design/methodology/approach: The paper presents a thorough, updated literature review, discusses typology and the best practices of environmental training, and presents a framework integrating environmental training and organizational results. Findings: A careful consideration allows identifying a significant theoretical gap related to the lack of theoretical references, best practices, and an alignment between environmental training and organizational results. To overcome this gap, a model was proposed that helps to manage the environmental training process in organizations. Research limitations/implications: The paper needs to be complemented with empirical research on the topic. Originality/value: Environmental training is considered to be an essential element for organizations seeking to mitigate their environmental impacts. ISO 14001 states that environmental management is a duty of certified organizations. However, there have been few published articles that suggest models and insights to improve the environmental training in organizations. © Emerald Group Publishing Limited.