Numerical Differentiation
Mostrando 1-12 de 34 artigos, teses e dissertações.
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1. Sensitivity analysis of 3D frictional contact with BEM using complex-step differentiation
Abstract This paper presents a study of the complex step differentiation method applied to a parameter sensitivity analysis for 3D elastic contact problem. The analysis is performed with the Boundary Element Method (BEM) using discontinuous elements and the Generalized Newton Method with line search (GNMls). A standard BEM implementation is used and the cont
Lat. Am. j. solids struct.. Publicado em: 22/10/2018
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2. A numerical method for free vibration analysis of beams
In this paper, a numerical method for solution of the free vibration of beams governed by a set of second-order ordinary differential equations of variable coefficients, with arbitrary boundary conditions, is presented. The method is based on numerical integration rather than the numerical differentiation since the highest derivatives of governing functions
Lat. Am. j. solids struct.. Publicado em: 2014-12
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3. A comparison of CA125, HE4, risk ovarian malignancy algorithm (ROMA), and risk malignancy index (RMI) for the classification of ovarian masses
OBJECTIVE: Differentiation between benign and malignant ovarian neoplasms is essential for creating a system for patient referrals. Therefore, the contributions of the tumor markers CA125 and human epididymis protein 4 (HE4) as well as the risk ovarian malignancy algorithm (ROMA) and risk malignancy index (RMI) values were considered individually and in comb
Clinics. Publicado em: 2012
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4. Diversificação evolutiva de gobídeos no litoral brasileiro: padrões citogenéticos e ecomorfológicos
The fishes of the order Perciformes are characterized as an important model for understanding the genetic structure of marine populations, because besides they present examples of conservation chromosomal, also they present the karyotype diversification for some groups. Gobiidae family is the most specious in the marine environment. Among its representatives
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/05/2011
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5. Diferenciação automática de matrizes Hessianas / Automatic differentiation of hessian matrices
In the context of nonlinear programming, many algorithms boil down to the application of Newton s method to the system constituted by the first order Lagrangian conditions. The calculation of Hessian matrices is necessary in this class of solvers. Our focus is on the exact calculation, within machine precision, of Hessian matrices through automatic different
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/04/2011
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6. Mathematical modeling of emulsion copolymerization process of butyl acrylate and vynil acetate. / Modelagem matemática do processo de copolimerização em emulsão de acrilato de butila e acetato de vinila.
Polimeric materials have been largely used and, today, more stringent specifications have been imposed to these materials for special applications. In general, microstructure exercises intense influence on the macroscopic properties of the polymer: therefore, the control of the microstructure and its relation with these properties is of strategic interest. M
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/04/2011
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7. A global linearization approach to solve nonlinear nonsmooth constrained programming problems
In this paper we introduce a new approach to solve constrained nonlinear non-smooth prograing probles ith any desirable accuracy even hen the objective function is a non-smooth one. In this approach for any given desirable accuracy, all the nonlinear functions of original problem (in objective function and in constraints) are approximated by a piecewise line
Computational & Applied Mathematics. Publicado em: 2011
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8. Simulador de meios porosos saturados elastoplasticos / Numerical simulator of saturated elastoplastic porous media
The exploration of mineral resources is growing in importance in the Brazilian economy. Since the environments in which these resources are found are becoming increasingly more complex and challenging for the production phase, currently unavailable knowledge and technologies are required to produce these reserves. In the particular well drilling and completi
Publicado em: 2009
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9. Computação evolutiva na resolução de equações diferenciais ordinárias não lineares no espaço de Hilbert. / Evolutive computation in the resolution of non-linear ordiinary diferential equations in the Hilbert space.
This thesis shows a new method to get polynomial solutions to the initial value problems (IVP), with an error margin comparable to the consecrate numerical methods (NM), for both the function and its derivatives. The method works with differential equations (DEs) linear or not, beeing the developed tolls available until 4th order, whose can be expanded to hi
Publicado em: 2009
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10. Citogenética molecular comparativa do DNAr 18S e 5S em piranhas (Serrasalminae, Characidae) Amazônia Central
Basic and molecular cytogenetic studies have been performed in 11 species of the subfamily Serrasalminae: Colossoma macropomum, Serrasalmus (S. altispinnis, S. elongatus, S. gouldingi, S. rhombeus, S. cf rhombeus, S. serrulatus and S. maculatus), Pygocentrus nattereri, Pristobrycon striolatus and Catoprion mento, collected along different sites in Central Am
Publicado em: 2007
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11. SOLUTION OF SYSTEMS OF EQUATIONS DIFFERENTIATE AND ALGEBRAIC: APPLICATION IN SYSTEMS OF ELECTRIC ENERGY / SOLUÇÃO DE SISTEMAS DE EQUAÇÕES DIFERENCIAS E ALGÉBRICAS: APLICAÇÃO EM SISTEMAS DE ENERGIA ELÉTRICA
The present work investigates and compares the computational performance of numerical techniques, selected from specialized literature and applied to the solution of large-scale algebraic and differential equations. Among the considered techniques, emphasis was given to the method known as MEBDF (Modified Extended Backward Differentiation Formulae), because
Publicado em: 2005
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12. Desenvolvimento de metodo implicito para simulador numerico tridimensional de escoamentos compressiveis inviscidos
The simulation of compressible flows considered inviscid is largely appliable to aeronautics. The development of such simulations using the Garlekin discontinuous method[7,12,16,20], wich presents the good characteristics of fine element and finite volume methods, benefitting from the polynomial interpolation within subdomains and discontinuous across interf
Publicado em: 2004