968 resultados para resource dependence theory


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The phenomenon of portfolio entrepreneurship has attracted considerable scholarly attention and is particularly relevant in the family fi rm context. However, there is a lack of knowledge of the process through which portfolio entrepreneurship develops in family firms. We address this gap by analyzing four in-depth, longitudinal family firm case studies from Europe and Latin America. Using a resource-based perspective, we identify six distinct resource categories that are relevant to the portfolio entrepreneurship process. Furthermore, we reveal that their importance varies across time. Our resulting resource-based process model of portfolio entrepreneurship in family firms makes valuable contributions to both theory and practice.

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How useful is a quantum dynamical operation for quantum information processing? Motivated by this question, we investigate several strength measures quantifying the resources intrinsic to a quantum operation. We develop a general theory of such strength measures, based on axiomatic considerations independent of state-based resources. The power of this theory is demonstrated with applications to quantum communication complexity, quantum computational complexity, and entanglement generation by unitary operations.

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Thesis (D.M.A.)--University of Washington, 2016-06

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The integration of geo-information from multiple sources and of diverse nature in developing mineral favourability indexes (MFIs) is a well-known problem in mineral exploration and mineral resource assessment. Fuzzy set theory provides a convenient framework to combine and analyse qualitative and quantitative data independently of their source or characteristics. A novel, data-driven formulation for calculating MFIs based on fuzzy analysis is developed in this paper. Different geo-variables are considered fuzzy sets and their appropriate membership functions are defined and modelled. A new weighted average-type aggregation operator is then introduced to generate a new fuzzy set representing mineral favourability. The membership grades of the new fuzzy set are considered as the MFI. The weights for the aggregation operation combine the individual membership functions of the geo-variables, and are derived using information from training areas and L, regression. The technique is demonstrated in a case study of skarn tin deposits and is used to integrate geological, geochemical and magnetic data. The study area covers a total of 22.5 km(2) and is divided into 349 cells, which include nine control cells. Nine geo-variables are considered in this study. Depending on the nature of the various geo-variables, four different types of membership functions are used to model the fuzzy membership of the geo-variables involved. (C) 2002 Elsevier Science Ltd. All rights reserved.

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We present here a tractable theory of transport of simple fluids in cylindrical nanopores, which is applicable over a wide range of densities and pore sizes. In the Henry law low-density region the theory considers the trajectories of molecules oscillating between diffuse wall collisions, while at higher densities beyond this region the contribution from viscous flow becomes significant and is included through our recent approach utilizing a local average density model. The model is validated by means of equilibrium as well nonequilibrium molecular dynamics simulations of supercritical methane transport in cylindrical silica pores over a wide range of temperature, density, and pore size. The model for the Henry law region is exact and found to yield an excellent match with simulations at all conditions, including the single-file region of very small pore size where it is shown to provide the density-independent collective transport coefficient. It is also shown that in the absence of dispersive interactions the model reduces to the classical Knudsen result, but in the presence of such interactions the latter model drastically overpredicts the transport coefficient. For larger micropores beyond the single-file region the transport coefficient is reduced at high density because of intermolecular interactions and hindrance to particle crossings leading to a large decrease in surface slip that is not well represented by the model. However, for mesopores the transport coefficient increases monotonically with density, over the range studied, and is very well predicted by the theory, though at very high density the contribution from surface slip is slightly overpredicted. It is also seen that the concept of activated diffusion, commonly associated with diffusion in small pores, is fundamentally invalid for smooth pores, and the apparent activation energy is not simply related to the minimum pore potential or the adsorption energy as generally assumed. (C) 2004 American Institute of Physics.

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We present results of application of the density functional theory (DFT) to adsorption and desorption in finite and infinite cylindrical pores accounting for the density distribution in radial and axial directions. Capillary condensation via formation of bridges is considered using canonical and grand canonical versions of the 2D DFT. The potential barrier of nucleation is determined as a function of the bulk pressure and the pore diameter. In the framework of the conventional assumptions on intermolecular interactions both 1D and 2D DFT versions lead to the same results and confirm the classical scenario of condensation and evaporation: the condensation occurs at the vapor-like spinodal point, and the evaporation corresponds to the equilibrium transition pressure. The analysis of experimental data on argon and nitrogen adsorption on MCM-41 samples seems to not completely corroborate this scenario, with adsorption branch being better described by the equilibrium pressure - diameter dependence. This points to the necessity of the further development of basic representations on the hysteresis phenomena.

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A comparison is made between Arrhenius and transition-state analyses of the temperature dependence of rate constants reported in four published biosensor studies. Although the Eyring transition-state theory seemingly affords a more definitive solution to the problem of characterizing the activation energetics, the analysis is equivocal because of inherent assumptions about reaction mechanism and the magnitude of the transmission coefficient. In view of those uncertainties it is suggested that a preferable course of action entails reversion to the empirical Arrhenius analysis with regard to the energy of activation and a preexponential factor. The former is essentially equivalent to the enthalpy of activation, whereas the magnitude of the latter indicates directly the extent of disparity between the frequency of product formation and the universal frequency factor (temperature multiplied by the ratio of the Boltzmann and Planck constants) and hence the likelihood of a more complicated kinetic mechanism than that encompassed by the Eyring transition-state theory. (C) 2004 Elsevier Inc. All rights reserved.

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We provide here a detailed theoretical explanation of the floating molecule or levitation effect, for molecules diffusing through nanopores, using the oscillator model theory (Phys. Rev. Lett. 2003, 91, 126102) recently developed in this laboratory. It is shown that on reduction of pore size the effect occurs due to decrease in frequency of wall collision of diffusing particles at a critical pore size. This effect is, however, absent at high temperatures where the ratio of kinetic energy to the solid-fluid interaction strength is sufficiently large. It is shown that the transport diffusivities scale with this ratio. Scaling of transport diffusivities with respect to mass is also observed, even in the presence of interactions.

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This economic evaluation was part of the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD) project. Data from four trials of heroin detoxification methods, involving 365 participants, were pooled to enable a comprehensive comparison of the cost-effectiveness of five inpatient and outpatient detoxification methods. This study took the perspective of the treatment provider in assessing resource use and costs. Two short-term outcome measures were used-achievement of an initial 7-day period of abstinence, and entry into ongoing post-detoxification treatment. The mean costs of the various detoxification methods ranged widely, from AUD $491 (buprenorphine-based outpatient); to AUD $605 for conventional outpatient; AUD $1404 for conventional inpatient; AUD $1990 for rapid detoxification under sedation; and to AUD $2689 for anaesthesia per episode. An incremental cost-effectiveness analysis was carried out using conventional outpatient detoxification as the base comparator. The buprenorphine-based outpatient detoxification method was found to be the most cost-effective method overall, and rapid opioid detoxification under sedation was the most costeffective inpatient method.

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Os ativos intangíveis receberam atenção especial de estudiosos nos últimos anos, no contexto organizacional de gestão de pessoas, visto que foram desenvolvidas propostas teóricas para compreendê-los e mensurá-los. Ancorados nesta linha de investigação, encontram-se o capital humano e o capital psicológico. Enquanto o capital humano representa o que os trabalhadores sabem fazer, o capital psicológico compreende um estado mental positivo composto por autoeficácia, esperança, otimismo e resiliência. Este estudo teve, como objetivo geral, analisar as relações entre capital humano e capital psicológico. Tratou-se de um estudo quantitativo do qual participaram 60 trabalhadores, estudantes do último período do Curso de Administração, com idade média de 23,85 anos, sendo a maioria do sexo feminino, solteira e empregada. Os dados para o estudo foram coletados em salas de aula de uma universidade particular, situada na Região do Grande ABC, por meio de um instrumento auto aplicável, contendo uma medida intervalar de capital psicológico com 12 itens, validada para o Brasil, e uma de capital humano com seis questões, sendo duas para medir a dimensão experiência e quatro para aferir educação. Foi criado um banco eletrônico, o qual foi submetido a análises descritivas e de correlação (r de Pearson) por meio do SPSS, versão 19.0. Os resultados revelaram que os participantes detinham um capital humano representado por 4,38 anos médios de experiência de trabalho , e que a maioria (75%) havia revelado possuir no máximo cinco anos neste quesito. Quanto à dimensão educação do capital humano, a maioria (96,70%) não havia concluído nenhum curso de graduação, se dedicou entre 11 a 20 anos aos estudos (81,60%), não realizou intercâmbios de estudos (93%), enquanto 86,70% já incluíram, em seu currículo acadêmico, atividades complementares previstas no Plano Pedagógico do Curso de Administração que cursavam, bem como 73,30% realizaram entre um a três estágios curriculares. As análises indicaram um escore mediano de capital psicológico, acentuado pela dificuldade dos participantes para reconhecerem que estavam em uma fase de sucesso no trabalho e de conseguirem enxergar o lado brilhante das coisas relativas ao trabalho. Ao se investigar as relações entre o capital humano e capital psicológico não foram encontradas correlações significativas. Diante de tais resultados, pareceu provável que os participantes do estudo, por serem predominantemente jovens trabalhadores que ainda não concluíram um curso de graduação, embora tivessem em seu percurso de vida mais de 10 anos dedicados aos estudos e trabalhado por volta de cinco anos em média, ainda não reconheciam, em si, a presença de um consistente capital humano nem psicológico. A ausência de relação observada entre os dois ativos intangíveis preconizados por teóricos como importantes, para que o trabalhador pudesse contribuir com a empresa no alcance de suas metas, pareceu revelar que ainda eram necessários mais estudos e desenvolvimento de teorização, para sustentar não somente as hipóteses acerca de ativos intangíveis, como também permitir identificar a relação de dependência que pudesse existir entre as categorias de capital humano e psicológico.

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Aquifers are a vital water resource whose quality characteristics must be safeguarded or, if damaged, restored. The extent and complexity of aquifer contamination is related to characteristics of the porous medium, the influence of boundary conditions, and the biological, chemical and physical processes. After the nineties, the efforts of the scientists have been increased exponentially in order to find an efficient way for estimating the hydraulic parameters of the aquifers, and thus, recover the contaminant source position and its release history. To simplify and understand the influence of these various factors on aquifer phenomena, it is common for researchers to use numerical and controlled experiments. This work presents some of these methods, applying and comparing them on data collected during laboratory, field and numerical tests. The work is structured in four parts which present the results and the conclusions of the specific objectives.