Results 21 to 30 of about 356,969 (310)
Determination of optimal nudging coefficients [PDF]
Tellus A: Dynamic Meteorology and Oceanography, 2003 A four-dimensional variational assimilation (4D-Var) scheme is now widely used by meteorological centres in a operational way. However, most of these applications do not take account of model error. Indeed, the classical 4D-Var with imperfect model formulation is unaffordable for current computational means.
Vidard, Arthur +2 more
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Two Inverse Problems Solution by Feedback Tracking Control
Axioms, 2021 Two inverse ill-posed problems are considered. The first problem is an input restoration of a linear system. The second one is a restoration of time-dependent coefficients of a linear ordinary differential equation.
Vladimir Turetsky
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Simultaneous Optimal Estimation of Roughness and Minor Loss Coefficients in a Pipeline
Mathematical and Computational Applications, 2020 This paper presents a proposal to estimate simultaneously, through nonlinear optimization, the roughness and head loss coefficients in a non-straight pipeline.
Ildeberto Santos-Ruiz +3 more
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On the optimal regularity of coefficients in hyperbolic Cauchy problems
Bulletin des Sciences Mathématiques, 2003 The authors consider the Cauchy problem for a second-order hyperbolic equation \[ \begin{gathered} u_{tt}(t, x)- a(t) u_{xx}(t, x)+ b(t) u_x(t, x)= 0,\quad [0, T]\times \mathbb{R}^n,\\ u(0, x)= \phi(x),\quad u_t(0, x)= \psi(x).\end{gathered} \] They prove that if the coefficients \(a(t)> 0\) and \(b(t)\) satisfy \[ \begin{alignedat}{2} |\partial^k_t a ...
COLOMBINI, FERRUCCIO +2 more
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OPTIMAL MODEL AVERAGING OF VARYING COEFFICIENT MODELS [PDF]
Statistica Sinica, 2019 We consider the problem of model averaging over a set of semiparametric varying coefficient models where the varying coefficients can be functions of continuous and categorical variables. We propose a Mallows model averaging procedure that is capable of delivering model averaging estimators with solid finite-sample performance.
Li, Cong +3 more
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Is there a growing social acceptance of earnings inequalities in Poland?
Annales Etyka w Życiu Gospodarczym, 2018 In our studies, we deal with the estimating of the optimal ranges of earnings – the optimal Gini indexes which are favourable to the maximisation of GDP growth in Poland.
Paweł Kumor
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Determination of Optimal Diffusion Coefficients in Lake Zirahuén through a Local Inverse Problem
Mathematics, 2021 In this study, optimal diffusion coefficients for Lake Zirahuén, Mexico, were found under particular conditions based on images taken with a drone of a dye release experiment.
Tzitlali Gasca-Ortiz +2 more
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Modification of Roughness Coefficients of Water Distribution Network Using Optimization Method [PDF]
رویکردهای نوین در مهندسی عمران, 2018 Due to the breadth and complexity of water distribution networks, modeling of these networks is essential for proper utilization and proper network management. Determination of network coefficients is the more importance in network modeling.
Hamid Azarvash, Mehdi Dini
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Weighted Optimal Quadrature Formulas in Sobolev Space and Their Applications
AlgorithmsThe optimization of computational algorithms is one of the main problems of computational mathematics. This optimization is well demonstrated by the example of the theory of quadrature and cubature formulas.
Kholmat Shadimetov, Khojiakbar Usmanov
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Optimal Control Systems by Time-Dependent Coefficients Using CAS Wavelets
Journal of Applied Mathematics, 2009 This paper considers the problem of controlling the solution of an initial boundary-value problem for a wave equation with time-dependent sound speed. The control problem is to determine the optimal sound speed function which damps the vibration of the ...
Taher Abualrub +2 more
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