10,990 Hits in 3.0 sec

Titelei/Inhaltsverzeichnis [chapter]

Jochen-Christoph Kaiser
2017 Hans von Soden  
Jochen-Christoph Kaiser (Hg.) Hans von Soden.  ... 
doi:10.5771/9783828869509-1 fatcat:nz6uufy7pzbfxdrzm3rg6y64ga

Identifikation von Interferenzschichtsystemen

Hans Kaiser, Hans-Christoph Kaiser
1988 Zeitschrift für Analysis und ihre Anwendungen  
KAISER definiert.  ...  KAISER und H.-C. KAISER Der so bestimrnte Invertierungsalgorithmus für die N bzv.  ... 
doi:10.4171/zaa/328 fatcat:yfyb5xav75ddlpuskfkzqvoyoq


Helmut Abels, Karoline Disser, Hans-Christoph Kaiser, Alexander Mielke, Marita Thomas
2021 Discrete and Continuous Dynamical Systems. Series S  
Kaiser Weierstrass Institute for Applied Analysis and Stochastics, Germany  ...  Editors Helmut Abels Fakultt für Mathematik, Universität Regensburg, Germany Karoline Disser Institut für Mathematik, Universität Kassel, Germany Hans-Christoph  ... 
doi:10.3934/dcdss.2021101 fatcat:6hel24xxkbbvdgz7weqdquutlu

Classical solutions of drift-diffusion equations for semiconductor devices: the 2d case [article]

Hans-Christoph Kaiser, Hagen Neidhardt, Joachim Rehberg
2007 arXiv   pre-print
We regard drift-diffusion equations for semiconductor devices in Lebesgue spaces. To that end we reformulate the (generalized) van Roosbroeck system as an evolution equation for the potentials to the driving forces of the currents of electrons and holes. This evolution equation falls into a class of quasi-linear parabolic systems which allow unique, local in time solution in certain Lebesgue spaces. In particular, it turns out that the divergence of the electron and hole current is an
more » ... function. Hence, Gauss' theorem applies, and gives the foundation for space discretization of the equations by means of finite volume schemes. Moreover, the strong differentiability of the electron and hole density in time is constitutive for the implicit time discretization scheme. Finite volume discretization of space, and implicit time discretization are accepted custom in engineering and scientific computing.--This investigation puts special emphasis on non-smooth spatial domains, mixed boundary conditions, and heterogeneous material compositions, as required in electronic device simulation.
arXiv:math/0701132v1 fatcat:aes6lwousjfbnhk4i4xvcuxwoi

Convexity of trace functionals and Schrödinger operators

Hans-Christoph Kaiser, Hagen Neidhardt, Joachim Rehberg
2006 Journal of Functional Analysis  
Let H be a semi-bounded self-adjoint operator on a separable Hilbert space. For a certain class of positive, continuous, decreasing, and convex functions F we show the convexity of trace functionals of the form tr(F (H + U − ε(U ))) − ε(U ), where U is a bounded, self-adjoint operator and ε(U ) is a normalizing real function-the Fermi level-which may be identical zero. If additionally F is continuously differentiable, then the corresponding trace functional is Fréchet differentiable and there
more » ... an expression of its gradient in terms of the derivative of F . The proof of the differentiability of the trace functional is based upon Birman and Solomyak's theory of double Stieltjes operator integrals. If, in particular, H is a Schrödinger-type operator and U a real-valued function, then the gradient of the trace functional is the quantum mechanical expression of the particle density with respect to an equilibrium distribution function f = −F . Thus, the monotonicity of the particle density in its dependence on the potential U of Schrödinger's operator-which has been understood since the late 1980s-follows as a special case.  2005 Elsevier Inc. All rights reserved.
doi:10.1016/j.jfa.2005.12.014 fatcat:xz2wi26lfnbzvlzv7cbvg54e5m

Density and current of a dissipative Schrödinger operator

Hans-Christoph Kaiser, Hagen Neidhardt, Joachim Rehberg
2002 Journal of Mathematical Physics  
doi:10.1063/1.1507825 fatcat:xf2xfyxrebcvdf32ccq7sjzo6i

Modelling and Simulation of Strained Quantum Wells in Semiconductor Lasers [chapter]

Hans-Christoph Kaiser, Uwe Bandelow, Thomas Koprucki, Joachim Rehberg
2003 Mathematics — Key Technology for the Future  
Talk at session of scientific committee of WIAS, WIAS, Berlin, oct 13 2000. • Uwe Bandelow, Herbert Gajewski, Hans-Christoph Kaiser, Thomas Koprucki, and Joachim Rehberg.  ...  Kaiser, and J. Rehberg.  ... 
doi:10.1007/978-3-642-55753-8_31 fatcat:p3epwyxhpzhrdob4khmx6dehoy

Analyticity for Some Operator Functions from Statistical Quantum Mechanics

Kurt Hoke, Hans-Christoph Kaiser, Joachim Rehberg
2009 Annales de l'Institute Henri Poincare. Physique theorique  
doi:10.1007/s00023-009-0419-7 fatcat:75ynrfbyzjf2nhjw45uibbmu2y

Elliptic model problems including mixed boundary conditions and material heterogeneities

Robert Haller-Dintelmann, Hans-Christoph Kaiser, Joachim Rehberg
2008 Journal des Mathématiques Pures et Appliquées  
We present model problems in three dimensions, where the operator −∇ · μ∇ maps the Sobolev space W 1,p The emphasis is here on the case where different boundary conditions meet material heterogeneities. Résumé Cet article présente des situations modèles, en trois dimensions, dans lesquelles l'opérateur −∇ · μ∇ est un isomorphisme de W 1,p Γ (Ω) sur W −1,p Γ (Ω) pour un p > 3. On s'intéresse notamment au cas où des conditions au bord mixtes Dirichlet/Neumann sont combinées avec des sauts du coefficient μ.
doi:10.1016/j.matpur.2007.09.001 fatcat:fnd2uezdajbwbpigf3qynsodwu

Hybrid Spline-Based Multimodal Registration Using Local Measures for Joint Entropy and Mutual Information [chapter]

Andreas Biesdorf, Stefan Wörz, Hans-Jürgen Kaiser, Christoph Stippich, Karl Rohr
2009 Lecture Notes in Computer Science  
We introduce a new hybrid approach for spline-based elastic registration of multimodal medical images. The approach uses point landmarks as well as intensity information based on local analytic measures for joint entropy and mutual information. The information-theoretic similarity measures are computationally efficient and can be optimized independently for each voxel. We have applied our approach to synthetic images, brain phantom images, as well as clinically relevant multimodal medical
more » ... . We also compared our measures with previous measures.
doi:10.1007/978-3-642-04268-3_75 fatcat:fvkeb7ft4jazlg2wsyf7orfma4

Structural connectivity changes in temporal lobe epilepsy: Spatial features contribute more than topological measures

Peter N. Taylor, Cheol E. Han, Jan-Christoph Schoene-Bake, Bernd Weber, Marcus Kaiser
2015 NeuroImage: Clinical  
This could be tested in the future using, for example, a computational model of spreading (Kaiser et al., 2007; Kaiser, 2013; Taylor et al., 2013) .  ...  Since so many ROIs have decreased surface area it is not surprising that alterations in connectivity have been observed in those studies which consequently impacts graph theoretic measures (Kaiser, 2011  ... 
doi:10.1016/j.nicl.2015.02.004 pmid:26106557 pmcid:PMC4473265 fatcat:watffzy2nzggto3mifdw2vn5jy

Switzerland: coronary and structural heart interventions from 2010 to 2015

Fabio Rigamonti, Gregor Fahrni, Micha Maeder, Stéphane Cook, Daniel Weilenmann, Peter Wenaweser, Christian Röthlisberger, Roberto Corti, Hans Rickli, Christoph Kaiser, Marco Roffi
2017 EuroIntervention  
doi:10.4244/eij-d-16-00828 pmid:28504236 fatcat:qidqksqkvfhmffv6dww6wf3nzy

Coronary Artery Disease Progression Late After Successful Stent Implantation

Michael J. Zellweger, Christoph Kaiser, Raban Jeger, Hans-Peter Brunner-La Rocca, Peter Buser, Franziska Bader, Jan Mueller-Brand, Matthias Pfisterer
2012 Journal of the American College of Cardiology  
Objectives This study sought to define the importance of 5-year coronary artery disease (CAD) progression after successful stenting. Background Safety concerns regarding first-generation drug-eluting stents mandate 5-year follow-up studies. However, only limited data exist on the long-term importance of CAD progression relative to late stent-related problems. Methods This study followed for 5 years, 428 consecutive patients randomized to drug-eluting versus bare-metal stents with successful
more » ... ting documented by freedom from symptoms/events and no ischemic perfusion defects (PDs) after 6 months. Rest/stress scintigraphic scans were repeated after 60 months. Late events and new PDs in areas remote from stented vessels indicated CAD progression. Results During follow-up, 110 of 428 (25.7%) patients had 150 clinical events: 43 patients (10%) died, 36 (8.4%) suffered a myocardial infarction, and 71 (16.6%) needed repeat revascularization. Event rates were lower in remote versus target-vessel areas (9.8% vs. 14.3%, p ϭ 0.019). Remote myocardial infarction and repeat revascularization accounted for 46 of 124 (37.1%) nonfatal events and were similar for both stent types. Five-year scintigraphic studies in patients without follow-up events showed 23.3% new PDs, 71% of which were asymptomatic. Remote defects accounted for 37.5% PDs and were similar for both stent types. Conclusions Even 5 years after stenting, target-vessel events and/or new PDs remained more frequent than CAD progression assessed by remote events and/or new PDs. Still, remote events accounted for almost 40% of all events with a similar rate of additional new PDs, often silent, and independent of stent type. This documents the importance of CAD progression and stresses the need to differentiate remote from target-vessel events/PDs in long-term stent safety studies. (Basel Stent Kosten-Effektivitäts Trial [BASKET]; ISRCTN75663024) (J Am Coll Cardiol 2012;59:793-9)
doi:10.1016/j.jacc.2011.11.024 pmid:22361397 fatcat:s3rauw3krvg57psjwulrjrmq6i

Psychometric evaluation of the Temporal Experience of Pleasure Scale (TEPS) in a German sample

Joe J. Simon, Johannes Zimmermann, Sheila A. Cordeiro, Ina Marée, David E. Gard, Hans-Christoph Friederich, Matthias Weisbrod, Stefan Kaiser
2018 Psychiatry Research  
Weisbrod and Kaiser received speaker honoraria from Roche and royalties for cognitive test and training software from Schuhfried (none related to this study).  ...  Another construct of interest is apathy, which has been defined as an impairment in goal-directed behavior due to a loss of motivation (Kaiser et al., 2016; Marin, 1991) .  ... 
doi:10.1016/j.psychres.2017.11.060 pmid:29195165 fatcat:cq64vczndbgjdivafvelfqmyp4

Are Scots pine forest edges particularly prone to drought-induced mortality?

Allan Buras, Christian Schunk, Claudia Zeiträg, Corinna Herrmann, Laura Kaiser, Hannes Lemme, Christoph Straub, Steffen Taeger, Sebastian Gößwein, Hans-Joachim Klemmt, Annette Menzel
2018 Environmental Research Letters  
Climate change is expected to exacerbate the frequency of drought-induced tree mortality world-wide. To better predict the associated change of species composition and forest dynamics on various scales and develop adequate adaptation strategies, more information on the mechanisms driving the often observed patchiness of tree die-back is needed. Although forest-edge effects may play an important role within the given context, only few corresponding studies exist. Here, we investigate the
more » ... die-back of Scots pine in Franconia, Germany, after a hot and dry summer in 2015, thereby emphasizing possible differences in mortality between forest edge and interior. By means of dendroecological investigations and close-range remote sensing, we assess long-term growth performance and current tree vitality along five different forest-edge distance gradients. Our results clearly indicate a differing growth performance between edge and interior trees, associated with a higher vulnerability to drought, increased mortality rates, and lower tree vitality at the forest edge. Prior long-lasting growth decline of dead trees compared to live trees suggests depletion of carbon reserves in course of a long-term drought persisting since the 1990s to be the cause of regional Scots pine die-back. These findings highlight the forest edge as a potential focal point of forest management adaptation strategies in the context of drought-induced mortality.
doi:10.1088/1748-9326/aaa0b4 fatcat:nlddw6bytfe3bnaxiggw34r7ya
« Previous Showing results 1 — 15 out of 10,990 results