1,135 research outputs found

    On inversion and connection coefficients for basic hypergeometric polynomials

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    In this paper, we propose a general method to express explicitly the inversion and the connection coefficients between two basic hypergeometric polynomial sets. As application, we consider some dd-orthogonal basic hypergeometric polynomials and we derive expansion formulae corresponding to all the families within the qq-Askey scheme.Comment: 15 page

    Blow-up results for semilinear wave equations in the super-conformal case

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    We consider the semilinear wave equation in higher dimensions with power nonlinearity in the super-conformal range, and its perturbations with lower order terms, including the Klein-Gordon equation. We improve the upper bounds on blow-up solutions previously obtained by Killip, Stovall and Vi\c{s}an [6]. Our proof uses the similarity variables' setting. We consider the equation in that setting as a perturbation of the conformal case, and we handle the extra terms thanks to the ideas we already developed in [5] for perturbations of the pure power case with lower order terms

    New Results On the Sum of Two Generalized Gaussian Random Variables

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    We propose in this paper a new method to compute the characteristic function (CF) of generalized Gaussian (GG) random variable in terms of the Fox H function. The CF of the sum of two independent GG random variables is then deduced. Based on this results, the probability density function (PDF) and the cumulative distribution function (CDF) of the sum distribution are obtained. These functions are expressed in terms of the bivariate Fox H function. Next, the statistics of the distribution of the sum, such as the moments, the cumulant, and the kurtosis, are analyzed and computed. Due to the complexity of bivariate Fox H function, a solution to reduce such complexity is to approximate the sum of two independent GG random variables by one GG random variable with suitable shape factor. The approximation method depends on the utility of the system so three methods of estimate the shape factor are studied and presented

    Monopolism versus Competition: Assessing Impacts on Export Capability (Comparative Study on Gum Arabic Export Merit)

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    This study aims to examine the impact of key policy changes on the gum Arabic sector after Gum Arabic Company concession withdrawn. Focusing on attitude of production and export performance. It is an attempt to contribute to solve the problem of huge decline and fluctuation of Gum Arabic production and exports in last decay. This decline had led to drop in revenues. Many factors were behind this problem ; part of them are naturally as drought, and mainly are human made as lack of policies and strategies of both government and the Gum Arabic Company (GAC),which was monopolized gum Arabic exports till recent years. The main object of the study was to evaluate the impact of de-monopolism policy on gum export performance, and generally, the paper intended to conduct comparative study between monopolism and competition. The study has formulated some hypotheses, concluded to that; monopolism policy of gum export is ineffective. Data has conducted through questionnaire, personal meeting, records and observation. Statistical Package of Social Studies (SPSS) has used to test the hypotheses and get results. The results confirmed that, monopolism policy is ineffective and mainly caused in the drop of the exports revenue and lowered Sudan world market share. Keywords: Gum Arabic, competition, monopolism, capability

    Strategic Planning Practices: A Key Success of Organization Growth and Development (A Case Study of Dal Group Company Ltd)

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    This paper asks to what extend strategic planning can have effects on organizations growth and development. Taking in consideration the issues that been raised by some researchers; that the strategic planning process tended to be inflexible since it operates in hyperactive changing environment and poorly  adapted to changing environment usually affected organization adversely. The main object of the study was to evaluate the impact of strategic planning on growth and development of manufacturing organizations in Sudan; a country marked by political and economic instability, due to multiple wars and USA economic sanctions, which extended for almost twenty years. More precisely the study focused on Dal Group Company Limited (DGCL).The study has formulated three hypotheses that have more effects on organization growth and development; setting objectives, organization structure, and budget allocations. Data has conducted through questionnaire, interviews, records and observation. Statistical Package of Social Studies (SPSS) has used to test the hypotheses and get results. The findings confirmed that, strategic planning has significant impact on the company growth and development. Therefore, the study revealed that, well implemented strategic planning is effective in an organization growth and development. This underscores the importance roles of strategic management, especially in light of volatile and turbulent environment. Keywords: Strategic planning, objectives, structure, budget, organization growth
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