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Optimal Selection of the Regularization Function in a Weighted Total Variation Model. Part II : Algorithm, Its Analysis and Numerical Tests

Based on the weighted total variation model and its analysis pursued in Hintermüller and Rautenberg 2016, in this paper a continuous, i.e., infinite dimensional, projected gradient algorithm and its convergence analysis are presented. The method computes a stationary point of a regularized bilevel optimization problem for simultaneously recovering the image as well as determining a spatially distr

Automated Parameter Selection for Total Variation Minimization in Image Restoration

Algorithms for automatically selecting a scalar or locally varying regularization parameter for total variation models with an Lτ-data fidelity term, τ∈ { 1 , 2 } , are presented. The automated selection of the regularization parameter is based on the discrepancy principle, whereby in each iteration a total variation model has to be minimized. In the case of a locally varying parameter, this amoun

Non-Overlapping Domain Decomposition Methods For Dual Total Variation Based Image Denoising

In this paper non-overlapping domain decomposition methods for the pre-dual total variation minimization problem are introduced. Both parallel and sequential approaches are proposed for these methods for which convergence to a minimizer of the original problem is established. The associated subproblems are solved by a semi-smooth Newton method. Several numerical experiments are presented, which sh

Subspace correction methods for a class of nonsmooth and nonadditive convex variational problems with mixed L1/L2 data-fidelity in image processing

The minimization of a functional composed of a nonsmooth and nonadditive regularization term and a combined L1 and L2 data-fidelity term is proposed. It is shown analytically and numerically that the new model has noticeable advantages over popular models in image processing tasks. For the numerical minimization of the new objective, subspace correction methods are introduced which guarantee the c

Frequency domain optical resolution photoacoustic and fluorescence microscopy using a modulated laser diode

In this paper a multimodal optical-resolution photoacoustic and fluorescence microscope in frequency domain is presented. Photoacoustic waves and modulated fluorescence are generated in chromophores by using a modulated diode laser. The photoacoustic waves, recorded with a hydrophone, and the fluorescence signals, acquired with an avalanche photodiode, are simultaneously measured using a lock-in t

Wavelet decomposition method for L2/TV-image deblurring

In this paper, we show additional properties of the limit of a sequence produced by the subspace correction algorithm proposed by Fornasier and Schönlieb [SIAM J. Numer. Anal., 47 (2009), pp. 3397-3428 for L2/TV-minimization problems. An important but missing property of such a limiting sequence in that paper is the convergence to a minimizer of the original minimization problem, which was obtaine

Bregmanized domain decomposition for image restoration

Computational problems of large-scale data are gaining attention recently due to better hardware and hence, higher dimensionality of images and data sets acquired in applications. In the last couple of years non-smooth minimization problems such as total variation minimization became increasingly important for the solution of these tasks. While being favorable due to the improved enhancement of im

A convergent overlapping domain decomposition method for total variation minimization

In this paper we are concerned with the analysis of convergent sequential and parallel overlapping domain decomposition methods for the minimization of functionals formed by a discrepancy term with respect to the data and a total variation constraint. To our knowledge, this is the first successful attempt of addressing such a strategy for the nonlinear, nonadditive, and nonsmooth problem of total

Using DUNE-ACFem for Non-smooth Minimization of Bounded Variation Functions

The utility of Dune-ACFem is demonstrated to work well for solving a non-smooth minimization problem over bounded variation functions by implementing a primal-dual algorithm. The implementation is based on the simplification provided by Dune-ACFem. Moreover, the convergence of the discrete minimizer to the continuous one is shown theoretically.

On the development of all-cellulose capsules by vesicle-templated layer-by-layer assembly

Polymeric multilayer capsules formed by the layer-by-layer (LbL) technique are interesting candidates for the purposes of storage, encapsulation, and release of drugs and biomolecules for pharmaceutical and biomedical applications. In the current study, cellulose-based core-shell particles were developed via the LbL technique alternating two cellulose derivatives, anionic carboxymethyl-cellulose (

GenetIC - A new initial conditions generator to support genetically modified zoom simulations

We present genetIC, a new code for generating initial conditions for cosmological N-body simulations. The code allows precise, user-specified alterations to be made to arbitrary regions of the simulation (while maintaining consistency with the statistical ensemble). These "genetic modifications"allow, for example, the history, mass, or environment of a target halo to be altered in order to study t

Well-being and dietary adherence in patients with coeliac disease depending on follow-up

Objective: It is not clear how follow-up of coeliac disease should be optimally organised. In Malmö, Sweden, patients are followed up by general practitioners (GP), but in Linköping by gastroenterologists (GE). The aim of this study was to investigate if there were any differences in well-being and dietary adherence depending on type of follow-up. Methods: All adult patients with newly diagnosed b

Is the General Factor of Personality really related to frequency of agreeable, conscientious, emotionally stable, extraverted, and open behavior? : An experience sampling study

Proponents of the general factor of personality have suggested that it is related to more instances of agreeable, conscientious, emotionally stable, extraverted, and open behavior. We tested this frequency hypothesis by relating the GFP from personality self-ratings to the number of instances of typical Big Five behaviors in real life. For a period of 18 consecutive days, 108 students provided res

Socially desirable responding in experience sampling : Consequences for personality research

Experience sampling often makes use of items that are similar to personality questionnaire items. Arguably, this opens up for item-popularity effects, where some respondents react to the items' level of evaluative phrasing, causing a separate factor. Gauging the risk of item popularity effects in experience sampling is important since the multifactorial aspect of the responses to the items may cau

Widespread non-joint pain in early rheumatoid arthritis

Objective: The aim of the study was to assess the development of widespread non-joint pain (WNP) in a cohort of patients with early rheumatoid arthritis (RA), the associated health-related quality of life (HRQoL), and clinical and demographic risk factors for WNP. Method: Incident cases with RA, from the Swedish population-based study Epidemiological Investigation of Rheumatoid Arthritis (EIRA), w

An ultra-low power high-precision logarithmic-curvature compensated all-CMOS voltage reference in 65 nm CMOS

In this paper, a low-complexity resistorless high-precision sub-1 V MOSFET-only voltage reference is presented. To obtain an accurate output, a curvature-compensation technique is used, canceling its logarithmic temperature dependence regardless of the value of the mobility temperature exponent (γ). The circuit is realized in 65 nm CMOS technology and yields an output voltage of 574 mV, a temperat

Chemoenzymatic Synthesis of Glycopeptides Bearing Galactose-Xylose Disaccharide from the Proteoglycan Linkage Region

Proteoglycans have important biological activities. To improve the overall synthetic efficiency, a new chemoenzymatic route has been established for the proteoglycan linkage region bearing a galactose-xylose disaccharide. The xylosylated glycopeptides were synthesized via solid phase synthesis, which was followed by the addition of the galactose unit by the galactosyl transferase β4GalT7. This wor

Predicting sample success for large-scale ancient DNA studies on marine mammals

In recent years, nonhuman ancient DNA studies have begun to focus on larger sample sizes and whole genomes, offering the potential to reveal exciting and hitherto unknown answers to ongoing biological and archaeological questions. However, one major limitation to such studies is the substantial financial and time investments still required during sample screening, due to uncertainty regarding succ