On an inverse problem in the theory of thermistors
An inverse problem for a nonlocal problem describing the temperature of a conducting device is studied.
On an inverse scattering problem for a discontinuous Sturm-Liouville equation with a spectral parameter in the boundary condition.
On the ersatz material approximation in level-set methods
The level set method has become widely used in shape optimization where it allows a popular implementation of the steepest descent method. Once coupled with a ersatz material approximation [Allaire et al., J. Comput. Phys.194 (2004) 363–393], a single mesh is only used leading to very efficient and cheap numerical schemes in optimization of structures. However, it has some limitations and cannot be applied in every situation. This work aims at exploring such a limitation. We estimate the systematic...
On the regular Sturm-Liouville transform.
Perturbations of the harmonic map equation
We consider perturbations of the harmonic map equation in the case where the source and target manifolds are closed riemannian manifolds and the latter is in addition of nonpositive sectional curvature. For any semilinear and, under some extra conditions, quasilinear perturbation, the space of classical solutions within a homotopy class is proved to be compact. For generic perturbations the set of solutions is finite and we present a count of this set. An important ingredient for our analysis is...
Problèmes inverses pour des équations différentielles sur la droite
Representation of the norming constants by two spectra.
Small Potential Corrections for the Discrete Eigenvalues of the Sturm-Liouville Problem.
Solving an inverse Sturm-Liouville problem by a Lie-group method.
Solving inverse nodal problem with frozen argument by using second Chebyshev wavelet method
We consider the inverse nodal problem for Sturm-Liouville (S-L) equation with frozen argument. Asymptotic behaviours of eigenfunctions, nodal parameters are represented in two cases and numerical algorithms are produced to solve the given problems. Subsequently, solution of inverse nodal problem is calculated by the second Chebyshev wavelet method (SCW), accuracy and effectiveness of the method are shown in some numerical examples.
Some converse theorems in the asymptotic theory of ordinary differential equations
Some new results in 1D inverse scattering
Spectral analysis for differential operators with singularities.
Spectral asymptotics for inverse nonlinear Sturm-Liouville problems.
Switched modified function projective synchronization between two complex nonlinear hyperchaotic systems based on adaptive control and parameter identification
This paper investigates adaptive switched modified function projective synchronization between two complex nonlinear hyperchaotic systems with unknown parameters. Based on adaptive control and parameter identification, corresponding adaptive controllers with appropriate parameter update laws are constructed to achieve switched modified function projective synchronization between two different complex nonlinear hyperchaotic systems and to estimate the unknown system parameters. A numerical simulation...
Symmetries of the nonlinear Schrödinger equation
Symmetries of the defocusing nonlinear Schrödinger equation are expressed in action-angle coordinates and characterized in terms of the periodic and Dirichlet spectrum of the associated Zakharov-Shabat system. Application: proof of the conjecture that the periodic spectrum of a Zakharov-Shabat operator is symmetric,i.e. for all , if and only if the sequence of gap lengths, , is symmetric with respect to .
The eigenvalues of symmetric Sturm-Liouville problem and inverse potential problem, based on special matrix and product formula
The Sturm-Liouville eigenvalue problem is symmetric if the coefficients are even functions and the boundary conditions are symmetric. The eigenfunction is expressed in terms of orthonormal bases, which are constructed in a linear space of trial functions by using the Gram-Schmidt orthonormalization technique. Then an -dimensional matrix eigenvalue problem is derived with a special matrix , that is, if is odd.Based on the product formula, an integration method with a fictitious time, namely...
The inverse carrier problem
The problem was motivated by Borůvka’s definitions of the carrier and the associated carrier. The inverse carrier problem is precisely defined and partially solved. Examples are given.
The inverse spectral problem for the Sturm-Liouville operators with discontinuous coefficients.
Востановление несамосопряженных дифференциальных операторов на полуоси по матрице Вейля