Now showing items 355-374 of 541

    • Noncommutative manifolds and Seiberg-Witten-equations 

      Alekseev, Vadim (2011-10-17)
      In this thesis we study differential geometry of noncommutative manifolds. We introduce a general framework of noncommutative manifolds based on Poincaré duality and study the notions of differential forms and Sobolev ...
    • Nonlinear Reconstruction Methods for Parallel Magnetic Resonance Imaging 

      Uecker, Martin (2009-10-14)
      Parallel acquisition techniques have been proposed to reduce the measurement times for magnetic resonance imaging. These techniques rely on the simultaneous acquisition of an undersampled ...
    • Nonparametric Methods in Spot Volatility Estimation 

      Schmidt-Hieber, Anselm Johannes (2011-01-06)
      This work is devoted to study a model, where we observe a stochastic process X under additional measurement noise. The main objective is to estimate a ``fluctuation measure``, called the volatility/intermittency of ...
    • Novel machine learning solutions for precision medicine - from causal inference to cellular perturbations and interactions 

      Schrod, Stefan (2024-10-04)
      Optimal therapy of complex diseases necessitates a shift from one-size-fits-all solutions towards personalized treatment plans. To achieve this, it is crucial to understand the casual effect of medical interventions, such ...
    • Novikov-Shubin Invariants of Nilpotent Lie Groups 

      Höpfner, Tim Martin (2023-05-25)
      Novikov-Shubin invariants are so-called L2-invariants of non-compact manifolds. They are defined using the Laplace operators and measure the density of their spectra near zero. This near-zero part of the spectrum is ...
    • Numerical Simulation of Bloch Equations for Dynamic Magnetic Resonance Imaging 

      Hazra, Arijit (2017-03-21)
      With recent advancements of image reconstruction techniques, magnetic resonance imaging (MRI) can produce real-time images at a temporal resolution of 10 to 40 ms to observe complex physiological processes and also serves ...
    • Numerical study of an evolutionary algorithm for electrical impedance tomography 

      Eckel, Harry (2008-03-03)
      We consider the two-dimensional inverse electrical impedance problem without a-priori information. There, we want to reconstruct the conductivity inside a conducting object from currents and voltages applied at its ...
    • Numerische Methoden zur Analyse hochdimensionaler Daten 

      Heinen, Dennis (2014-09-10)
      This thesis is concerned with two of the major tasks in processing huge data sets, dimensionality reduction and data denoising. The first part of the thesis yields a summary on dimensionality reduction. Dimensionality ...
    • Obere und untere Schranken für eingeschränkte Parity-Branchingprogramme 

      Brosenne, Henrik (2006-08-15)
      Boolean Functions are classified in complexity classes by the upper and lower bounds of the resources a computation required to solve the function in a certain computation model.Thus one ...
    • Oktaven und Reduktionstheorie 

      Roeseler, Karsten (2012-02-02)
      The thesis studies the split octonion algebra and its automorphism group. This group is a Lie group of Type G2. One object of the thesis is to look at methods introduced by Behrend, Harder ...
    • On a Two Dimensional Inverse Scattering Problem for a Dielectric 

      Altundag, Ahmet (2012-03-05)
      The inverse problem under consideration is to reconstruct the shape of an infinitely long homogeneous dielectric cylinder from the far field (or near field) pattern for scattering of a ...
    • On an analogue of L2-Betti numbers for finite field coefficients and a question of Atiyah 

      Neumann, Johannes (2016-07-12)
      We construct a dimension function for modules over the group ring of an amenable group. This may replace the von Neumann dimension in the definition of L2-Betti numbers and thus allows an analogue definition for finite ...
    • 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 ...
    • On C*-algebras associated to product systems 

      Fabre Sehnem, Camila (2018-05-17)
      We consider a class of Fell bundles over quasi-lattice ordered groups. We show that these are completely determined by the positive fibres and that their cross sectional C*-algebras are relative Cuntz–Pimsner algebras ...
    • On Collective Communication and Notified Read in the Global Address Space Programming Interface (GASPI) 

      End, Vanessa (2017-03-28)
      In high performance computing (HPC) applications, scientific or engineering problems are solved in a highly parallel and often necessarily distributed manner. The distribution of work leads to the distribution of data ...
    • On Combinatorial Properties of Subsequences 

      Koß, Tore (2024-08-22)
      A word, also known as string, is a sequence of letters, while a subsequence of a word w is another word u which can be obtained by deleting some of the letters of w. Words in general, and subsequences in particular, play ...
    • On Localization and Multiscale in Data Assimilation 

      Nadeem, Aamir (2017-06-01)
      The main goal of inverse problems is the reconstruction of unknown quantities, often they are located in an inaccessible part of space. Data assimilation, which is the integration of inverse problems techniques with dynamical ...
    • On Localization Issues of Mobile Devices 

      Yuan, Yali (2018-11-05)
      Mobile devices, such as sensor nodes, smartphones and smartwatches, are now widely used in many applications. Localization is a highly important topic in wireless networks as well as in many Internet of Things applications. ...
    • On Lower Bounds for Parity Branching Programs 

      Homeister, Matthias (2003-12-18)
      This thesis concerns the complexity of parity branching programs with limitations on the way in which variables may be read.Interest in such branching programs has been raised by a popular ...
    • On minimax detection of localized signals from indirect or correlated data 

      Pohlmann, Markus (2022-05-05)
      This is a cumulative thesis consisting of two papers, in which we treat two problems related to the detectability of local anomalies within certain types of data. In the first paper, we suppose that a segment of a Gaussian ...