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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 171 to 175 of 175 (0.05 seconds)Spelling suggestions: "subject:"werteinteilung"" "subject:"artenverteilung""
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Strategies of Sexual Reproduction in Aphids / Fortpflanzungsstrategien der Sexuellen Generation von BlattläusenDagg, Joachim 30 October 2002 (has links)
No description available.
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| 172 |
Studies on two specific inverse problems from imaging and financeRückert, Nadja 20 July 2012 (has links) (PDF)
This thesis deals with regularization parameter selection methods in the context of Tikhonov-type regularization with Poisson distributed data, in particular the reconstruction of images, as well as with the identification of the volatility surface from observed option prices.
In Part I we examine the choice of the regularization parameter when reconstructing an image, which is disturbed by Poisson noise, with Tikhonov-type regularization. This type of regularization is a generalization of the classical Tikhonov regularization in the Banach space setting and often called variational regularization. After a general consideration of Tikhonov-type regularization for data corrupted by Poisson noise, we examine the methods for choosing the regularization parameter numerically on the basis of two test images and real PET data.
In Part II we consider the estimation of the volatility function from observed call option prices with the explicit formula which has been derived by Dupire using the Black-Scholes partial differential equation. The option prices are only available as discrete noisy observations so that the main difficulty is the ill-posedness of the numerical differentiation. Finite difference schemes, as regularization by discretization of the inverse and ill-posed problem, do not overcome these difficulties when they are used to evaluate the partial derivatives. Therefore we construct an alternative algorithm based on the weak formulation of the dual Black-Scholes partial differential equation and evaluate the performance of the finite difference schemes and the new algorithm for synthetic and real option prices.
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| 173 |
Studies on two specific inverse problems from imaging and financeRückert, Nadja 16 July 2012 (has links)
This thesis deals with regularization parameter selection methods in the context of Tikhonov-type regularization with Poisson distributed data, in particular the reconstruction of images, as well as with the identification of the volatility surface from observed option prices.
In Part I we examine the choice of the regularization parameter when reconstructing an image, which is disturbed by Poisson noise, with Tikhonov-type regularization. This type of regularization is a generalization of the classical Tikhonov regularization in the Banach space setting and often called variational regularization. After a general consideration of Tikhonov-type regularization for data corrupted by Poisson noise, we examine the methods for choosing the regularization parameter numerically on the basis of two test images and real PET data.
In Part II we consider the estimation of the volatility function from observed call option prices with the explicit formula which has been derived by Dupire using the Black-Scholes partial differential equation. The option prices are only available as discrete noisy observations so that the main difficulty is the ill-posedness of the numerical differentiation. Finite difference schemes, as regularization by discretization of the inverse and ill-posed problem, do not overcome these difficulties when they are used to evaluate the partial derivatives. Therefore we construct an alternative algorithm based on the weak formulation of the dual Black-Scholes partial differential equation and evaluate the performance of the finite difference schemes and the new algorithm for synthetic and real option prices.
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| 174 |
Rohstoffprognosen für Zinn, Wolfram, Fluss- und Schwerspat im MittelerzgebirgeBrosig, Andreas, Barth, Andreas, Knobloch, Andreas, Dickmayer, Ellen 04 January 2022 (has links)
Im Rahmen des Projektes ROHSA 3 wurden auf Basis vorhandener und neu verfügbar gemachter Daten Prognosen für Zinn, Wolfram sowie Fluss- und Schwerspat in einem 740 m² großen Gebiet im Mittelerzgebirge angefertigt. Die Karten zeigen höffige Gebieten, wobei für Zinn und Wolfram erstmals auch Mengen-Prognosen erstellt wurden. Geophysikalische, geochemische Daten sowie Lagerstättenindikatoren (z. B. Tektonik, Erz kontrollierende Lithologien) wurden durch die Software advangeo@ aufbereitet und mittels ihrer künstlich neuronalen Netze (KNN) verarbeitet. Durch höhere Datendichte, Einbeziehung dreidimensionaler geologischer Daten und Aufstellung quantitativer Modelle wurde ein deutlicher Erkenntnisfortschritt erzielt.
Redaktionsschluss: 31.07.2020
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| 175 |
Photodissoziation von Halogenwasserstoff- und orientierten Wasserstoff-Edelgas-Halogen-Molekülen in Clusterumgebungen / Photodissociation of hydrogen halide and oriented hydrogen-rare gas-halogen molecules in cluster environmentsNahler, Nils Hendrik 28 October 2002 (has links)
No description available.
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