Suche
Anzeige der Dokumente 11-20 von 30
Dissertation
Zur Konvergenz der Randpunktmethode
(2008-09-24)
Das von Maz'ya eingeführte Approximationsverfahren, die Methode der näherungsweisen Näherungen (Approximate Approximations), kann auch zur numerischen Lösung von Randintegralgleichungen verwendet
werden (Randpunktmethode). In diesem Fall hängen die Komponenten der Matrix des resultierenden Gleichungssystems zur Berechnung der Näherung für die Dichte nur von der Position der Randpunkte und der Richtung der äußeren Einheitsnormalen in diesen Punkten ab. Dieses numerisches Verfahren wird am Beispiel des Dirichlet ...
Dissertation
Influence of the buffer environment on the Relative Biological Effectiveness of carbon ion radiation, investigated by Scanning Force Microscopy and gel electrophoresis
(2008-06-06)
This work focuses on the analysis of the influence of environment on the relative biological effectiveness (RBE) of carbon ions on molecular level. Due to the high relevance of RBE for medical applications, such as tumor therapy, and radiation protection in space, DNA damages have been investigated in order to understand the biological efficiency of heavy ion radiation. The contribution of this study to the radiobiology research consists in the analysis of plasmid DNA damages induced by carbon ion radiation in ...
Aufsatz
Effect of dressing on high-order harmonic generation in vibrating H2 molecules
(American Physical Society, 2008-04-03)
Wir entwickeln die Starkfeldnäherung für die Erzeugung hoher Harmonischer in Wasserstoffmolekülen, wobei die Vibrationsbewegung berücksichtigt wird, sowie die laserinduzierte Kopplung zwischen den beiden untersten Born-Oppenheimer-Zuständen im Molekülion, das durch die anfängliche Ionisation des Moleküls erzeugt wird. Wir zeigen, dass die Kopplung bei längeren Laserwellenlängen (≈ 2 μm) wichtig wird und zu einer Reduzierung der Erzeugung von Harmonischen führt, sowie zu einer Änderung des Verhältnisses von Harmonischen ...
Dissertation
Entanglement analysis of atomic processes and quantum registers
(2008-09-24)
During recent years, quantum information processing and the study of N−qubit quantum systems have attracted a lot of interest, both in theory and experiment. Apart from the promise of performing efficient quantum information protocols, such as quantum key distribution, teleportation or quantum computation, however, these investigations also revealed a great deal of difficulties which still need to be resolved in practise.
Quantum information protocols rely on the application of unitary and non–unitary quantum ...
Preprint
Construction of recurrent fractal interpolation surfaces(RFISs) on rectangular grids
(2008)
A recurrent iterated function system (RIFS) is a genaralization of an IFS and provides
nonself-affine fractal sets which are closer to natural objects. In general, it's attractor
is not a continuous surface in R3. A recurrent fractal interpolation surface (RFIS) is an
attractor of RIFS which is a graph of bivariate continuous interpolation function. We
introduce a general method of generating recurrent interpolation surface which are at-
tractors of RIFSs about any data set on a grid.
Preprint
Construction of fractal interpolation surfaces on rectangular grids
(2008)
We present a general method of generating continuous fractal interpolation surfaces
by iterated function systems on an arbitrary data set over rectangular grids and estimate
their Box-counting dimension.
Dissertation
Vergleichend anatomische Studien an den nasalen und vomeronasalen olfaktorischen Organen der Anuren unter funktionsmorphologischen und phylogenetischen Aspekten
(2008-07-11)
Gegenüber anderen sensorischen Systemen wie z. B. optischer oder akustischer Wahrnehmung wurde der olfaktorische Sinn der Anuren von wissenschaftlicher Seite her in der Vergangenheit eher vernachlässigt. Dementsprechend gering sind auch die Erkenntnisse bezüglich der biologischen Bedeutung von Gerüchen für die Froschlurche sowie das Verständnis der damit verbundenen physiologischen Abläufe.
Wie die meisten Tetrapoden besitzen auch Anuren ein mehrteiliges Geruchsorgan, welches im Wesentlichen aus dem klassischen ...
Preprint
The Parity of the Number of Irreducible Factors for Some Pentanomials
(2008)
It is well known that Stickelberger-Swan theorem is very important for determining reducibility of polynomials over a binary field. Using this theorem it was determined the parity of the number of irreducible factors for some kinds of polynomials over a binary field, for instance, trinomials,
tetranomials, self-reciprocal polynomials and so on. We discuss this problem for type II pentanomials namely x^m +x^{n+2} +x^{n+1} +x^n +1 \in\ IF_2 [x].
Such pentanomials can be used for efficient implementing multiplication ...
Preprint
On Nonlinear Preconditioners in Newton-Krylov-Methods for Unsteady Flows
(2008)
The application of nonlinear schemes like dual time stepping as preconditioners in matrix-free Newton-Krylov-solvers is considered and analyzed. We provide a novel formulation of the left preconditioned operator that says it is in fact linear in the matrix-free sense, but changes the Newton scheme. This allows to get some insight in the convergence properties of these schemes which are demonstrated through numerical results.
Preprint
Parity of the Number of Irreducible Factors for Composite Polynomials
(2008)
Various results on parity of the number of irreducible factors of given polynomials over finite fields have been obtained in the recent literature. Those are mainly based on Swan’s theorem in which discriminants of polynomials over a finite field or the integral ring Z play an important role. In this paper we consider discriminants of the composition of some polynomials over finite fields. The relation between the discriminants of composed polynomial and the original ones will be established. We apply this to obtain ...