Results 21 to 30 of about 547,161 (285)
Renormalization techniques for quantum spin systems. Ground-state energies [PDF]
, 1980 Projection of the Hamiltonian of an antiferromagnetic lattice of spins , without external fields, onto a subspace of the total spinor space gives an approximation for the lowest eigenvalue of this Hamiltonian.
Caspers, W.J.
core +2 more sources
On the Approximation of Delayed Systems by Taylor Series Expansion [PDF]
Journal of Computational and Nonlinear Dynamics, 2015 It is known that stability properties of delay-differential equations are not preserved by Taylor series expansion of the delayed term. Still, this technique is often used to approximate delayed systems by ordinary differential equations in different engineering and biological applications.
openaire +1 more source
Gain Scheduling Controller Synthesis for Control Moment Gyroscope Using Improved Approximation
SICE Journal of Control, Measurement, and System Integration, 2018 This paper presents gain scheduling (GS) control of a variable speed control moment gyroscope (VSCMG) based on sum of squares (SOS). Nonlinear motion equations of the VSCMG are complicated because they contain many trigonometric functions of angles of ...
Toru Inaba, Gan Chen, Isao Takami
doaj +1 more source
An Operator-Based Scheme for the Numerical Integration of FDEs
Mathematics, 2021 An operator-based scheme for the numerical integration of fractional differential equations is presented in this paper. The generalized differential operator is used to construct the analytic solution to the corresponding characteristic ordinary ...
Inga Timofejeva +4 more
doaj +1 more source
Applied Sciences, 2020 This paper proposes a new method to get explicit expressions of some quantities associated with performance analysis of the maximum likelihood DOA algorithm in the presence of an additive Gaussian noise on the antenna elements.
Ji Woong Paik, Kyu-Ho Lee, Joon-Ho Lee
doaj +1 more source
Results in Physics, 2018 Simple analytic approximations valid for x⩾0 have been found for the modified Bessel functions I2(x) and I2/3(x), used amply in Electromagnetism and Mechanics applications.
Pablo Martin +3 more
doaj +1 more source
, 2022 The article is devoted to the mean-square approximation of iterated Ito and Stratonovich stochastic integrals in the context of the numerical integration of Ito stochastic differential equations.
Kuznetsov, Dmitriy F.
core +1 more source
Approximation of Probability Density Functions for PDEs with Random Parameters Using Truncated Series Expansions [PDF]
Vietnam Journal of Mathematics, 2021 The probability density function (PDF) of a random variable associated with the solution of a partial differential equation (PDE) with random parameters is approximated using a truncated series expansion. The random PDE is solved using two stochastic finite element methods, Monte Carlo sampling and the stochastic Galerkin method with global polynomials.
Giacomo Capodaglio +2 more
openaire +3 more sources
A High Order Theory for Linear Thermoelastic Shells: Comparison with Classical Theories
Journal of Engineering, 2013 A high order theory for linear thermoelasticity and heat conductivity of shells has been developed. The proposed theory is based on expansion of the 3-D equations of theory of thermoelasticity and heat conductivity into Fourier series in terms of ...
V. V. Zozulya
doaj +1 more source
Sub-Wavelength Plasmonic Crystals: Dispersion Relations and Effective Properties [PDF]
, 2009 We obtain a convergent power series expansion for the first branch of the dispersion relation for subwavelength plasmonic crystals consisting of plasmonic rods with frequency-dependent dielectric permittivity embedded in a host medium with unit ...
Fortes, Santiago +2 more
core +4 more sources