1,741,271 research outputs found
Inverse problems and conformal mapping
No full textIn this exposition we give a unified presentation of the conformal mapping technique that was developed over the last decade by Akduman et al. [I. Akduman and R. Kress, Electrostatic imaging via conformal mapping, Inverse Probl. 18 (2002), pp. 1659-1672; R. Kress, Inverse Dirichlet problem and conformal mapping, Math. Comput. Simul. 66 (2004), pp. 255-265; H. Haddar and R. Kress, Conformal mappings and inverse boundary value problems, Inverse Probl. 21 (2005), pp. 935-953; H. Haddar and R. Kress, Conformal mapping and an inverse impedance boundary value problem, J. Inverse Ill-Posed Probl. 14 (2006), pp. 785-804; H. Haddar and R. Kress, Conformal mapping and impedance tomography, Inverse Probl. 26 (2010), p. 074002] for the inverse problem to recover three different types of inclusions in a homogeneous conducting background medium from Cauchy data on the accessible exterior boundary. The main ingredient of this method is a nonlinear and nonlocal ordinary differential equation for boundary values of a holomorphic function in an annulus bounded by two concentric circles that maps this annulus conformally onto the unknown domain. Furthermore, in a concluding section we illustrate how this differential equation also can be applied to numerically construct conformal mappings for doubly connected domains including numerical examples
[H.E.B. store next to construction of Kress]
No full textPhoto of H.E.B. next to the construction of Kress. Austin, Texas
University Scholar Series: Monika Kress
Get PDFMeteorites and the Origin of Habitable Worlds
On November 30, 2011, Dr. Monika Kress spoke in the University Scholar Series hosted by Provost Gerry Selter at the Dr. Martin Luther King, Jr. Library. Monika Kress is an Associate Professor of Physics and Astronomy at SJSU and also a member of the NASA Astrobiology Institute\u27s Virtual Planetary Laboratory. In this seminar, she presents the theory of solar system formation, focusing on meteorites. Dr. Kress also describes a first-hand account of how meteorites are recovered from the most fertile meteorite-hunting ground on Earth: Antarcticahttps://scholarworks.sjsu.edu/uss/1010/thumbnail.jp
An iterative method for a two-dimensional inverse scattering problem for a dielectric
No full textThe inverse problem under consideration is to reconstruct the shape of a homogeneous dielectric infinite cylinder from the far field pattern for scattering of a time-harmonic E-polarized electromagnetic plane wave. We propose an inverse algorithm that extends the approach suggested and investigated by Kress and Rundell for the electrostatic case and by Ivanyshyn and Kress for the time-harmonic case when the scattering object is a perfect conductor. It is based on a system of nonlinear boundary integral equations associated with a single-layer potential approach to solve the forward scattering problem. We present the mathematical foundations of the method and exhibit its feasibility by numerical examples
Electrical impedance tomography using a point electrode inverse scheme for complete electrode data
No full textFor the two dimensional inverse electrical impedance problem in the case of piecewise constant conductivities with the currents injected at adjacent point electrodes and the resulting voltages measured between the remaining electrodes, in [3] the authors proposed a nonlinear integral equation approach that extends a method that has been suggested by Kress and Rundell [10] for the case of perfectly conducting inclusions. As the main motivation for using a point electrode method we emphasized on numerical difficulties arising in a corresponding approach by Eckel and Kress [4, 5] for the complete electrode model. Therefore, the purpose of the current paper is to illustrate that the inverse scheme based on point electrodes can be successfully employed when synthetic data from the complete electrode model are used.German Ministry of Education and Researc
On the far-field operator in elastic obstacle scattering
No full textWe investigate the far-field operator for the scattering of time-harmonic elastic plane waves by either a rigid body, a cavity, or an absorbing obstacle. Extending results of Colton & Kress for acoustic obstacle scattering, for the spectrum of the far-field operator we show that there exist an infinite number of eigenvalues and determine disks in the complex plane where these eigenvalues lie. In addition, as counterpart of an identity in acoustic scattering due to Kress & Paivarinta, we will establish a factorization for the difference of the far-field operators for two different scatterers. Finally, extending a sampling method for the approximate solution of the acoustic inverse obstacle scattering problem suggested by Kirsch to elasticity, this factorization is used for a characterization of a rigid scatterer in terms of the eigenvalues and eigenelements of the far-field operator
Newton's method for inverse obstacle scattering meets the method of least squares
No full textThe inverse scattering problem of how to image the shape of a scatterer D from the far-field pattern u(infinity) for the scattering of time-harmonic waves can be interpreted as a nonlinear ill-posed operator equation F(partial derivativeD) = u(infinity) with the operator F mapping the boundary onto the far field. We will review recent results on regularized Newton iteration methods as applied to the above equation and present first ideas of an alternative approach that resembles a least-squares method for the solution of inverse obstacle scattering problems due to Kirsch and Kress and does not require a forward solver
Letter from Melville L. Kress to Upton Sinclair - January 15, 1939
No full textA letter from Melville Kress to Upton Sinclair, dated January 15th, 1939, in which Kress responds to Sinclair's request to know more about him. Kress writes about his personal and professional life, passions, thoughts, and wishes
Letter from Melville L. Kress to Upton Sinclair - January 20, 1935
No full textA letter from Melville Kress to Upton Sinclair, dated January 20th, 1935, in which Kress questions Sinclair at length about his belief in a 'personal God' statement when Kress believed him to not have such belief
Letter from Melville L. Kress to Upton Sinclair - March 23, 1939
No full textA letter from Melville Kress to Upton Sinclair, dated March 23rd, 1939, in which Kress responds to the corrections from Sinclair and proposes he send more copies of 'World's End' for Kress to 'test' with various level readers
- …
