Results 241 to 250 of about 1,197,623 (286)

Quadratures for Implicit Differential Equations

SIAM Journal on Numerical Analysis, 1970
Quadrature methods are used to obtain numerical solutions of certain systems of implicit differential equations. Development of the methods leads to an extension of an existence theorem for implicit differential equations. Several examples indicate the range of application of the methods.
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Triangular differential quadrature

Communications in Numerical Methods in Engineering, 2000
Summary: We propose a triangular differential quadrature method, where the partial derivative of a function with respect to space variables at a given point is approximated by a weighted linear summation of function values at all discrete points in a triangular domain.
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THE MODIFIED DIFFERENTIAL QUADRATURES AND THEIR APPLICATIONS

Chemical Engineering Communications, 1993
Abstract In this paper, a number of modifications are instituted in implementing the quadrature method for solving chemical engineering problems with semi-infinite domains and/or steep gradients. This improvement in the curve-fitting ability of differential quadratures is achieved by adopting trial functions of forms other than the polynomials.
CHUEI-TIN CHANG†, CHII-SHANG TSAI, TIEN-TSAI LIN   +2 more
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Differential Encoding for Quadrature-Amplitude Modulation

2010 IEEE 71st Vehicular Technology Conference, 2010
In this paper, we propose a novel differential encoder for QAM (quadrature-amplitude modulation), by a look-up table instead of a rule. Using a table for differential encoding has the advantages of both low complexity and good error performance. We propose algorithms to construct the table for maximizing the minimum noncoherent distance and minimizing ...
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THE GENERALIZED DIFFERENTIAL QUADRATURE RULE FOR INITIAL-VALUE DIFFERENTIAL EQUATIONS

Journal of Sound and Vibration, 2000
Summary: The generalized differential quadrature rule (GDQR) proposed recently by the authors is applied here to solve initial-value differential equations of the 2nd to 4th order. Differential quadrature expressions are derived based on the GDQR for these equations. The Hermite interpolation functions are used as trial functions to obtain the explicit
Wu, T.Y., Liu, G.R.
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Numerical Differentiation, Quadrature and Interpolation

2004
A series of ef formulae tuned on functions of the form (3.38) or (3.39) are derived here by the procedure described in the previous chapter. We construct the ef coefficients for approximations of the first and the second derivative of y(x), for a set of quadrature rules, and for some simple interpolation formulae.
Liviu Gr. Ixaru, Guido Vanden Berghe
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The generalized differential quadrature rule for fourth‐order differential equations

International Journal for Numerical Methods in Engineering, 2001
AbstractThe generalized differential quadrature rule (GDQR) proposed here is aimed at solving high‐order differential equations. The improved approach is completely exempted from the use of the existing δ‐point technique by applying multiple conditions in a rigorous manner.
Wu, T.Y., Liu, G.R.
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Differential phase quadrature surface profiling interferometer

Applied Optics, 1990
This paper describes an optical surface profiling system based on phase quadrature differential interferometry. The optical path difference between two adjacent optical probe beams is measured. Interference phase calculation and sample scanning is controlled by a PC computer.
B A, Omar, A J, Holloway, D C, Emmony
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Differential Equations Solvable by Quadrature

1992
By a differential equation with separable variables we understand the equation of the form $$y'{\text{ }} = {\text{ }}f(x)g(y)$$ (1)
Gheorghe Micula, Paraschiva Pavel
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On the solution of the thomas-fermi equation by differential quadrature

Journal of Computational Physics, 1984
This paper presents a method of finding approximate solutions to the Thomas-Fermi equation \(d^ 2f/dx^ 2=f^{3/2}/x^{1/2}\) with \(f=1\) at \(x=0\) and \(f=0\) as \(x\to \infty\). The essential approximation used is that for any linear operator L \(L(f(x_ i))\simeq \sum^{N}_{j=1}W_{ij}f(x_ j),\) \(i=1,2,...,N\) where \(x_ i\) are sample points and \(W_ ...
Civan, Faruk, Sliepcevich, C. M.
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