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Showing 1 to 20 of 109 for “"Finite differences"”.
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Orbital-free density functional theory using higher-order finite differences
… a real-space formulation and higher-order finite-difference implementation of periodic Orbital-free Density Functional Theory (OF-DFT). Specifically, utilizing a local reformulation of the electrostatic and kernel terms, we develop a generalized framework suitable for performing OF-DFT …
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Wavelets and wavelet optimized-finite differences for electronic structure calculations
… few functions. Using the Wavelet Optimized Finite Difference Method (WOFD) [1], wavelets can also be used to determine a grid for finite difference calculations. In one dimension, starting with a guess for the wavefunction on a coarse grid with few points, an accurate solution on a nouniform …
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Very large scale finite differences in modeling of seismic waves
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1995.
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The Other Calculus: a Survey of the Calculus of Finite Differences
The Calculus of Finite Differences is a fascinating field of mathematics which is easily accessible to an undergraduate mathematics major. This paper attempts to present a broad survey of results from this field which show its richness, without appealing to deep results in analysis. Topics covered …
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Analysis of Cylindrical Shell Roofs by Use of Energy Principles and Finite Differences
Made available in DSpace on 2014-12-05T17:37:38Z (GMT). No. of bitstreams: 1 6303219.pdf: 4692888 bytes, checksum: 02509f5adbd0149f4e1c8231dd51bc01 (MD5) Previous issue date: 1962
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Método das equivalências aplicado a placas esconsas
… by the numerical methods of equivalences, finite differences and finite elements, applied to several cases of skew plates with built in edges. Convergence towards the analytic solution has been examinated for different skew angles, and a study of time increasing with the number of joints …
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Análise do adensamento da fundação da barragem de Juturnaíba
… are presented as well as the numerical method of finite differences, the mathematical tool used in this thesis. The program CONMULTM (conceived by the L.C.P.C. - Paris), based on the finite differences method for the solution of unidimensional consolidation problems is described. Researches …
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Numerical Prediction of Three-Dimensional Incompressible Recirculating Flows
… flow over a backward-facing step, using finite-differences and the Navier-Stokes equations in primitive variables.
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Theoretical Studies in Two-Phase Flow Prior to the Transition to Detonation in Granular Solid Propellants
… governing equations are solved by the method of finite differences. Details of two distinct numerical methods to solve these nonlinear, coupled hyperbolic partial differential equations simultaneously are also presented. In addition, artificial smearing techniques which are generally needed for …
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Sensitivity analysis and computational shape optimization for incompressible flows
… of the inflow. The problem is discretized using finite elements. Optimization algorithms are considered which use either finite differences or sensitivities to estimate the gradient of the cost functional. Problems of scaling, local minimization, and cost functional regularization are considered. …
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Kippe em hastes retas em regime elasto-plástico
… buckling equations are solved by the method of finite differences, both in the elastic and the elasto-plastic range. Relevant results are discussed in a special chapter. In order to avoid, more involved questions, numerical treatments have been restricted to steel beams with rectangular …
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Topics in Optimization and Sparse Linear Systems
… for large sparse Symmetric Positive Definite Diagonally Dominant (SPDDD) linear systems. These kinds of linear systems arise in the solution of scalar second order PDEs for Heat Transfer, Electrostatics, Electromagnetics, Ground Water Flow, and Diffusion (with or without reaction) when …
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ΑΡΙΘΜΗΤΙΚΗ ΜΕΛΕΤΗ ΤΗΣ ΤΡΙΔΙΑΣΤΑΤΗΣ ΠΑΡΑΚΤΙΑΣ ΚΥΚΛΟΦΟΡΙΑΣ ΜΕ ΑΛΓΕΒΡΙΚΟΥΣ ΜΕΤΑΣΧΗΜΑΤΙΣΜΟΥΣ
… ARE TRANSFORMED TO THE CURVILINEAR SYSTEM. A FINITE-VOLUME (ALGEBRAIC TRANSFORMATIONS+FINITE DIFFERENCES) NUMERICAL SCHEME DEVELOPED TO SOLVE THE THREE-DIMENSIONAL AND TWO-DIMENSIONAL MODELS. THE VERACITY OF THE MODEL IS CHECKED BY ITS APPLICATION TO A SIMPLIFIED FLOW DOMAIN AND TO …
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Um modelo de malha irregular para o Método das Diferenças Finitas
… of the irregular meshes in the Method of Finite Differences, which makes the solution of partial differential equations possible up to the second order. The process is, thus, applied to the solution of simply supported plates and of plates under a plane stress state. Preliminarly, we study …
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ΜΑΘΗΜΑΤΙΚΗ ΠΕΡΙΓΡΑΦΗ ΤΗΣ ΔΙΑΔΟΣΗΣ ΤΩΝ ΜΗ ΓΡΑΜΜΙΚΩΝ ΔΙΑΣΠΕΙΡΟΜΕΝΩΝ ΚΥΜΑΤΙΣΩΝ ΣΤΟΝ ΠΑΡΑΚΤΙΟ ΧΩΡΟ
… OF EQUATIONS IS PROPOSED, BASED ON A CENTRAL FINITE DIFFERENCES SCHEME, WITH THIRD ORDER ACCURACY. THE CORRECTION TERMS, FROM TRUNCATION ERRORS, ARE INCLUDED IN THE F.D. INTEGRATION. BY INTRODUCINGA DIFFUSION TERM, TO SIMULATE TURBULENCE, WE PROPOSE AN EXTENSION OF THE BOUSSINESQ EQUATIONS IN …
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Perfilagem do problema de resolução da equação da onda por diferenças finitas em coprocessador Xeon Phi
… using performance metrics, the optimization of a finite differences code that solve the wave equation in isotropic media (ISO) in two dimensional (2D) and also, transverse tilted isotropic (TTI) three dimensional (3D) media. The objective is to measure the number of floating point operations per …
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Multiple steady solutions and bifurcations in the symmetric driven cavity
… terms. Spatial derivatives are evaluated with finite differences, and matrix equations are treated with SOR by lines. The results show symmetric solutions for low Reynolds numbers and asymmetric solutions for higher Reynolds numbers. Subcritical bifurcations are observed for two-dimensional …
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Three dimensional heterogeneous finite element method for static multi-group neutron diffusion
… heterogeneity. A three-dimensional Heterogeneous Finite Element Method (HFEM) is developed to address the limitations of current methods by offering fine-group energy representation and fuel-pin-level spatial detail at modest computational cost. The calculational cost of the method is roughly …
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Análise de transientes hidráulicos em oleodutos
… via the method of characteristics. Using finite differences these ordinary differential equations are then transformed into algebric equations which may be solved on a computer. The program developed here models equipments usually found in the petrol industry for transporting fluids …
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Análise de estruturas laminares pelo Método da Energia Discretizada
… on energy principles through a special form of finite differences. It does not depend on the boundary conditions and uses the concept of matrix of elements in which the structures are discretized. The objective of this work is the analysis of plates using cylindrical coordinates, subjected to …
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