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    • A new approach to the investigation of Iwasawa invariants 

      Kleine, Sören (2015-01-05)
      Let K be a fixed number field, let p be a prime number, and let Z_p denote the additive group of p-adic integers. The growth of the p-Sylow subgroups of the ideal class groups of the intermediate fields in a Z_p-extension ...
    • A unified framework for spline estimators 

      Schwarz, Katsiaryna (2013-07-09)
      This dissertation develops a uni ed framework to study the (asymptotic) properties of all (periodic) spline based estimators, that is of regression, penalized and smoothing splines. The explicit form of the periodic ...
    • Classical Conjectures in Iwasawa Theory for the split prime Z_p-extension and the cyclotomic Z_p-extension 

      Müller, Katharina (2021-04-15)
      This thesis constist of three parts. The first one considers the so called split prime Z_p extension over an imaginary quadratic field in which the rational prime p splits. In this setup we discuss the mu=0 conjecture as ...
    • Cryptanalysis of the Fuzzy Vault for Fingerprints: Vulnerabilities and Countermeasures 

      Tams, Berend-Benjamin (2013-07-08)
      The fuzzy fingerprint vault is a popular approach to protect a fingerprint's minutiae as a building block of a security application. In this thesis simulations of several attack scenarios are conducted against implementations ...
    • Cyclotomic Norm Diophantine Equations 

      Chen, Han (2023-10-25)
      In this thesis, I consider two Diophantine norm equations. For the equation of the Nagell-Ljunggren equation $\frac{x^p-1}{x-1} = p^e y^q$ with distinct odd prime exponents $p, q$, I show that, for $p > 3$, it has no ...
    • Diophantine Representation in Thin Sequences 

      Baur, Stefan (2016-08-24)
      In this work we investigate conditions under which forms of arbitrary degree represent almost all elements of thin sequences (especially the set of squares). Stronger results are given for forms of degree 3 and 4.
    • Exakte Moduln über dem von Manuel Köhler beschriebenen Ring 

      Grande, Vincent (2018-11-13)
      When proving an equivariant universal coefficient theorem for C*-Algebras acted on by a finite cyclic group Z/pZ, Manuel Köhler introduces the endomorphism ring R of the tuple (C,C(G),D). The aim of this thesis is to show ...
    • Fingerprint Growth Prediction, Image Preprocessing and Multi-level Judgment Aggregation 

      Gottschlich, Carsten (2011-01-06)
      Finger growth is studied in the first part of the thesis and a method for growth prediction is presented. The effectiveness of the method is validated in several tests. Fingerprint image ...
    • Fourier and Variational Based Approaches for Fingerprint Segmentation 

      Hoang Thai, Duy (2015-05-22)
      Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing ...
    • Hierarchically linked extended features for fingerprint processing 

      Mieloch, Krzysztof (2009-03-23)
      This thesis discusses a novel approach for fingerprint feature extraction. A new fingerprint structure has been proposed as a basis for the extraction of extended features. These new features ...
    • Julia Set as a Martin Boundary 

      Islam, Md. Shariful (2010-11-18)
      The Julia set of the class of hyperbolic rational maps having a totally disconnected Julia set is here identified as the Martin boundary of a Markov chain by using symbolic dynamics. When ...
    • Modelling and Analysing Orientation Fields of Fingerprints 

      Hotz, Thomas (2007-09-21)
      Global features of fingerprints, the most useful of which are orientation fields, are deployed for classification, image enhancement, and to define intrinsic coordinates. We thus strive for ...
    • On Artin's primitive root conjecture 

      Ambrose, Christopher Daniel (2014-07-15)
      Artin’s primitive root conjecture states that for any integer a, neither 0, ±1 nor a perfect square, there exist infinitely many primes p such that a is a primitive root modulo p, or alternatively, such that a generates a ...
    • Some Aspects on Coarse Homotopy Theory 

      Norouzizadeh, Behnam (2010-01-08)
      The most important examples of coarse spaces arise from proper metrics on spaces or from metrisable compactifications. In both cases, the bounded subsets are precisely the relatively compact ones. On the other hand, one ...
    • Statistical Inference for Propagation Processes on Complex Networks 

      Manitz, Juliane (2014-07-29)
      Scientists of various research fields have discovered the advantages of network-centric analysis, which captures complex systems by networks and allows for their representation as a collection of nodes connected by links. ...
    • The Barban-Davenport-Halberstam for tuples of k-free numbers 

      Parry, Tomos (2020-10-23)
      An asymptotic formula for variance of tuples of k-free numbers in arithmetic progressions
    • The Capitulation Problem in Class Field Theory 

      Bembom, Tobias (2012-04-10)
      We develop Chevalley's Theorem and interesting implications. Revisiting Galois Cohomology we analyse the structure of the capitulation kernel. Moreover investigate the growth of ideal classes and consequences of a ...
    • The split prime μ-conjecture and further topics in Iwasawa theory 

      Crisan, Vlad-Cristian (2019-03-25)
      The thesis is divided in three independent chapters, each focused on a different problem in Iwasawa theory. In Chapter 1 we prove the split prime μ-conjecture for abelian extensions of imaginary quadratic fields. In Chapter ...
    • Twisted Kloosterman sums and cubic exponential sums 

      Louvel, Benoît (2009-12-15)
      In this thesis work, we study the problem of the distribution of cubic exponential sums. Using the theory of of automorphic forms, we are able to determine the asymptotic behavior of these ...
    • Two Cases of Artin's Conjecture 

      Kaesberg, Miriam Sophie (2021-02-25)
      Let $f_1, \dots, f_R$ be forms of degree $k_1, \dots, k_R$ in $s$ variables. A generalised version of a conjecture by Artin states that the equations $f_1= \dots=f_R=0$ have a non-trivial $p$-adic solution for all primes ...