Kreß, Rainer

[["dc.bibliographiccitation.firstpage","2192"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","IEEE Transactions on Geoscience and Remote Sensing"],["dc.bibliographiccitation.lastpage","2199"],["dc.bibliographiccitation.volume","43"],["dc.contributor.author","Yapar, A."],["dc.contributor.author","Sahinturk, H."],["dc.contributor.author","Akduman, I."],["dc.contributor.author","Kress, Rainer"],["dc.date.accessioned","2018-11-07T10:55:21Z"],["dc.date.available","2018-11-07T10:55:21Z"],["dc.date.issued","2005"],["dc.description.abstract","A method to reconstruct the one-dimensional profile of a cylindrical layer with an inhomogeneous impedance boundary is proposed. Through the finite Fourier transformation of the field expressions the problem is first reduced to the solutions of a two-coupled system of operator equations which is solved iteratively starting from an initial estimate of the profile. The reconstruction of the profile is achieved by linearizing one of the equations in the Newton sense. The method is tested by considering several numerical examples and yields satisfactory reconstructions. As is typical for Newton-type methods, the convergence of the iteration depends on the initial guess."],["dc.identifier.doi","10.1109/TGRS.2005.855068"],["dc.identifier.isi","000232192800004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49765"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0196-2892"],["dc.title","One-dimensional profile inversion of a cylindrical layer with inhomogeneous impedance boundary: A Newton-type iterative solution"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","939"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Inverse Problems"],["dc.bibliographiccitation.lastpage","954"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Akduman, I."],["dc.contributor.author","Kress, Rainer"],["dc.contributor.author","Yapar, A."],["dc.date.accessioned","2018-11-07T09:45:22Z"],["dc.date.available","2018-11-07T09:45:22Z"],["dc.date.issued","2006"],["dc.description.abstract","A new, simple and fast method is presented for determining the location and the shape of a one-dimensional rough interface between two lossy dielectric half-spaces. The reconstruction is obtained from a set of reflected field measurements for a single illumination by a plane wave at a fixed frequency. Through a special representation of the scattered field in the half-spaces above and below the interface in terms of a Fourier transform and a Taylor expansion the problem is first reduced to the solution of a system of two nonlinear operator equations. Then this system is solved iteratively by alternating between a linear equation for a spectral coefficient of the scattered wave and a linearization of a nonlinear equation for the surface profile. The numerical simulations show that the method yields satisfactory reconstructions for slightly rough surface profiles."],["dc.identifier.doi","10.1088/0266-5611/22/3/013"],["dc.identifier.isi","000238422400016"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34602"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0266-5611"],["dc.title","Iterative reconstruction of dielectric rough surface profiles at fixed frequency"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","PII S0266-5611(02)37141-7"],["dc.bibliographiccitation.firstpage","1659"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Inverse Problems"],["dc.bibliographiccitation.lastpage","1672"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Akduman, I."],["dc.contributor.author","Kress, Rainer"],["dc.date.accessioned","2018-11-07T09:45:12Z"],["dc.date.available","2018-11-07T09:45:12Z"],["dc.date.issued","2002"],["dc.description.abstract","We present the solution of an inverse boundary value problem for harmonic functions arising in electrostatic imaging through conformal mapping techniques. The numerical method consists of two parts. In a first step, by successive approximations a nonlinear equation is solved to determine the boundary values of a holomorphic function on the outer boundary circle of an annulus. Then in a second step an ill-posed Cauchy problem is solved to determine the holomorphic function in the annulus. The method extends and modifies an earlier analysis of Idemen and Akduman (Idemen M and Akduman I 1988 SIAM J. Appl. Math. 48 703-18). We establish a convergence result for the iteration procedure and through numerical examples we illustrate the feasibility of the method."],["dc.identifier.doi","10.1088/0266-5611/18/6/315"],["dc.identifier.isi","000180001900017"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34563"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0266-5611"],["dc.title","Electrostatic imaging via conformal mapping"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","1055"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Radio Science"],["dc.bibliographiccitation.volume","38"],["dc.contributor.author","Akduman, I."],["dc.contributor.author","Kress, Rainer"],["dc.date.accessioned","2018-11-07T10:38:17Z"],["dc.date.available","2018-11-07T10:38:17Z"],["dc.date.issued","2003"],["dc.description.abstract","[1] The direct and inverse scattering problems related to objects having inhomogeneous impedance boundaries are addressed by considering cylindrical bodies. In the solution of the direct scattering problem, the scattered field is first expressed in terms of a combined single- and double-layer potential through Green's formula and the boundary condition. By using the jump relations on the boundary of the object, the scattering problem is reduced to a boundary integral equation that can be solved via a Nystrom method. The aim of the inverse impedance problem is to reconstruct the inhomogeneous surface impedance of the body from the measured far field data. Here representing the scattered field as a single- layer potential leads to an ill-posed integral equation of the first kind for the density that requires stabilization for its numerical solution; for example, by Tikhonov regularization. With the aid of the jump relations the single- layer potential enables the evaluation of the total field and its derivative on the boundary of the scatterer. Consequently, from the boundary condition the surface impedance can be reconstructed either by direct evaluation or by a minimum norm solution in the least squares sense. The numerical results show that our methods yields good resolution both for the direct and the inverse problem."],["dc.identifier.doi","10.1029/2002RS002631"],["dc.identifier.isi","000183633400001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45775"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Geophysical Union"],["dc.relation.issn","0048-6604"],["dc.title","Direct and inverse scattering problems for inhomogeneous impedance cylinders of arbitrary shape"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]