Eckart Deutsch, Christoph Zenger,
Tópico(s): Matrix Theory and Algorithms
1971 - Springer Science+Business Media | Numerische Mathematik
Tópico(s): Graph theory and applications
1972 - Springer Science+Business Media | Numerische Mathematik
Tópico(s): Material Science and Thermodynamics
1978 - Springer Science+Business Media | Numerische Mathematik
M. Breuer, F. Durst, Christoph Zenger,
Tópico(s): Distributed and Parallel Computing Systems
2002 - Springer Nature | Lecture notes in computational science and engineering
T. Störtkuhl, Christoph Zenger, Scott Zimmer,
In this paper, we analyse the behaviour of the solution of the Navier—Stokes equations near the corner of the driven cavity where the moving band touches the wall. At this point, the solution is singular. Since the singularity does not depend on the Reynolds number, it is sufficient to study the problem in the case of infinite viscosity, which is governed by the Stokes equations. We present an analytical asymptotic solution near the corner. Furthermore, numerical results are given, which were gained ...
Tópico(s): Lattice Boltzmann Simulation Studies
1994 - Emerald Publishing Limited | International Journal of Numerical Methods for Heat &Fluid Flow
Judith Hartmann, Andreas Krahnke, Christoph Zenger,
Due to the increasing gap between speed of CPU and speed of access to memory the latter is often the main bottleneck in modern high performance computing. Hierarchical cache architectures designed to avoid this problem conflict with the rather irregular memory access of modern adaptive multilevel algorithms which cause frequent cache misses. In this paper we present an algorithm for an adaptive multilevel FE solver that reduces random access and jumps in address space considerably. The grid is based ...
Tópico(s): Advanced Numerical Methods in Computational Mathematics
2007 - Elsevier BV | Applied Numerical Mathematics
Michael Bäder, Christoph Zenger,
One of the keys to tap the full performance potential of current hardware is the optimal utilization of cache memory. Cache oblivious algorithms are designed to inherently benefit from any underlying hierarchy of caches, but do not need to know about the exact structure of the cache. In this paper, we present a cache oblivious algorithm for matrix multiplication. The algorithm uses a block recursive structure and an element ordering that is based on Peano curves. In the resulting code, index jumps ...
Tópico(s): Interconnection Networks and Systems
2006 - Elsevier BV | Linear Algebra and its Applications
Frank Günther, Miriam Mehl, Markus Pögl, Christoph Zenger,
Competitive numerical algorithms for solving partial differential equations have to work with the most efficient numerical methods like multigrid and adaptive grid refinement and thus with hierarchical data structures. Unfortunately, in most implementations, hierarchical data—typically stored in trees—cause a nonnegligible overhead in data access. To overcome this quandary—numerical efficiency versus efficient implementation—our algorithm uses space‐filling curves to build up data structures which ...
Tópico(s): Distributed and Parallel Computing Systems
2006 - Society for Industrial and Applied Mathematics | SIAM Journal on Scientific Computing
A new extension of the Hindley/Milner type system is proposed. The type system has algebraic types, that have not only type parameters but also value parameters (indices). This allows for example to parameterize matrices and vectors by their size and to check size compatibility statically. This is especially of interest in computer algebra.
Tópico(s): Computability, Logic, AI Algorithms
1997 - Elsevier BV | Theoretical Computer Science
Hans–Joachim Bungartz, F. Durst, Christoph Zenger,
Since the creation of the term "Scientific Computing" and of its German counterpart "Wissenschaftliches Rechnen" (whoever has to be blamed for that), scientists from outside the field have been confus
Tópico(s): Scientific Computing and Data Management
1999 - Springer Nature | Lecture notes in computational science and engineering
Th. Belling, Th. Grauschopf, Sven Krüger, Markus Mayer, Folke Nörtemann, Markus Staufer, Christoph Zenger, Notker Rösch,
A density functional method for electronic structure calculations of atoms, molecules and clusters has been parallelized and newly implemented in the program ParaGauss. Parallelization strategies and performance aspects are discussed. The capabilities of this new quantum chemical code, which includes an option for scalar-relativist ic calculations, are demonstrated by all-electron results for large transition metal clusters (Pd309, Au38(SH)24).
Tópico(s): Catalytic Processes in Materials Science
1999 - Springer Nature | Lecture notes in computational science and engineering
Aryeh Shander, Susan M. Goobie, Matthew A. Warner, Matti Aapro, Elvira Bisbe, Ángel Augusto Pérez-Calatayud, Jeannie Callum, Melissa M. Cushing, Wayne B. Dyer, J. Erhard, David Faraoni, Shannon L. Farmer, Т. А. Федорова, Steven M. Frank, Bernd Froessler, H. Gombotz, Irwin Gross, Nicole R. Guinn, Thorsten Haas, Jeffrey M. Hamdorf, James P. Isbister, Mazyar Javidroozi, Hongwen Ji, Young‐Woo Kim, Daryl J. Kor, Johann Kurz, Sigismond Lasocki, Michael F. Leahy, Cheuk‐Kwong Lee, Jeong Jae Lee, Vernon Louw, Jens Meier, Anna Mezzacasa, Manuel Múñoz, Sherri Ozawa, Marco Pavesi, Nina Shander, Donat R. Spahn, Bruce D. Spiess, Jackie Thomson, Kevin M. Trentino, Christoph Zenger, Axel Hofmann,
The World Health Organization (WHO) has declared coronavirus disease 2019 (COVID-19), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a pandemic. Global health care now faces unprecedented challenges with widespread and rapid human-to-human transmission of SARS-CoV-2 and high morbidity and mortality with COVID-19 worldwide. Across the world, medical care is hampered by a critical shortage of not only hand sanitizers, personal protective equipment, ventilators, ...
Tópico(s): Trauma, Hemostasis, Coagulopathy, Resuscitation
2020 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
M. Griebel, W. Huber, T. Störtkuhl, Christoph Zenger,
In this paper we study the parallel solution of elliptic partial differential equations with the sparse grid combination technique. This algorithmic concept is based on the independent solution of many problems with reduced size and their linear combination. We describe the algorithm for three-dimensional problems and discuss its parallel implementation on a network of HP720 workstations and on vector computers.
Tópico(s): Advanced Numerical Methods in Computational Mathematics
1993 - Springer Science+Business Media | Lecture notes in computer science
M. Griebel, Christoph Zenger, Stefan Zimmer,
Tópico(s): Geophysics and Gravity Measurements
1993 - Springer Science+Business Media | Computing
Martin Backschat, Alexander Pfaffinger, Christoph Zenger,
Dynasty is a scalable hierarchical system for dynamic load distribution of general divide&conquer applications on large heterogeneous networks of workstations. It is based on economical principles with prices as the basic instrument for regulating offer and demand. The performance of Dynasty is evaluated by a Finite Element application running on up to 96 workstations.
Tópico(s): Cloud Computing and Resource Management
1996 - Springer Science+Business Media | Lecture notes in computer science
Robert Balder, Christoph Zenger,
Sparse grids provide a very efficient method for the multilinear approximation of functions, especially in higher-dimensional spaces. In the d-dimensional space, the nodal multilinear basis on a grid with mesh size $h = 2^{ - n} $ consists of $O(2^{nd} )$ basis functions and leads to an $L\_2$-error of order $O(4^{ - n} )$ and an $H\_1$-error of order $O(2^{ - n} )$. -With sparse grids we get an $L\_2$-error of order $O(4^{ - n} n^{d - 1} )$ and an $H\_1$-error of order $O(2^{ - n} )$ with only $O(2^n n^{d - 1} )$ basis functions, if the function ...
Tópico(s): Matrix Theory and Algorithms
1996 - Society for Industrial and Applied Mathematics | SIAM Journal on Scientific Computing
A. Lucic, Maximilian Emans, Franz Mayinger, Christoph Zenger,
Abstract An interferometric study and a numerical simulation are presented of the combined process of the bulk turbulent convection and the dynamic of a vapor bubble which is formed in the superheated boundary layer of a subcooled flowing liquid, in order to determine the heat transfer to the flowing subcooled liquid. In this investigation focus has been given on a single vapor bubble at a defined cavity site to provide reproducible conditions. In the experimental study single bubbles were generated ...
Tópico(s): Particle Dynamics in Fluid Flows
2004 - Elsevier BV | International Journal of Heat and Fluid Flow
Hans–Joachim Bungartz, Michael Griebel, Dierk Röschke, Christoph Zenger,
Tópico(s): Computational Fluid Dynamics and Aerodynamics
1996 - Elsevier BV | Mathematics and Computers in Simulation
Martin Odersky, Christoph Zenger, Matthias Zenger,
We present a type system for a language based on F ≤, which allows certain type annotations to be elided in actual programs. Local type inference determines types by a combination of type propagation and local constraint solving, rather than by global constraint solving. We re ne the previously existing local type inference system of Pierce and Turner[PT98] by allowing partial type information to be propagated. This is expressed by coloring types to indicate propagation directions. Propagating ...
Tópico(s): Natural Language Processing Techniques
2001 - Association for Computing Machinery | ACM SIGPLAN Notices
Hans–Joachim Bungartz, Wolfgang Eckhardt, Tobias Weinzierl, Christoph Zenger,
A PDE solver's value is increasingly co-determined by its memory footprint, as the increase of computational multicore power overtakes the memory access speed, and as memory restricts the maximum experiment size. Tailoring a code to require less memory is technical challenging, error-prone, and hardware-dependent. Object-oriented code typically consumes much memory, though developers favour such high-level languages offering meaningful models and good maintainability. We augment the language C++ ...
Tópico(s): Advanced Mathematical Modeling in Engineering
2009 - Elsevier BV | Future Generation Computer Systems
Shmuel Friedland, Christoph Zenger,
A vector norm |·|on the space of n×n complex valued matrices is called stable if for some constant K&>0, not depending upon A or m, we have |Am|⩽K|A|m We show that such a norm is stable if and only if it dominates the spectralradius.
Tópico(s): Matrix Theory and Algorithms
1984 - Elsevier BV | Linear Algebra and its Applications
Michael Griebel, W. Huber, Christoph Zenger,
The parallel numerical solution of the Navier-Stokes equations with the sparse grid combination method was studied. This algorithmic concept is based on the independent solution of many problems with reduced size and their linear combination. The algorithm for three-dimensional problems is described and its application to turbulence simulation is reported. Statistical results on a pipe flow for Reynolds number Re cl = 6950 are presented and compared with results obtained from other numerical simulations ...
Tópico(s): Meteorological Phenomena and Simulations
1996 - | Notes on numerical fluid mechanics
Lukas Durrer, Thomas Helbling, C. Zenger, A. Jungen, Christoph Stampfer, Christofer Hierold,
We investigated the growth of individual single-walled carbon nanotubes (SWNTs) by chemical vapor deposition (CVD) on Ferritin-based Fe catalyst. According to Ferritin adsorption measurements by atomic force microscope (AFM) imaging, we show that the SWNT density on the surface can be controlled by the Ferritin concentration in the adsorption solution, which is important for SWNT integration and avoiding SWNT bundle formation. The grown SWNTs were contacted by Cr/Au layers, structured by electron beam ...
Tópico(s): Force Microscopy Techniques and Applications
2007 - Elsevier BV | Sensors and Actuators B Chemical
Simone Laister, Barbara Stockinger, Anna-Maria Regner, Karin Zenger, Ute Knierim, Christoph Winckler,
Using heart rate (HR) measurements we investigated whether potential calming effects of social licking were evident for both active (performers) and passive (receivers) licking partners. A HR decline was assumed to indicate relaxation and thus the experience of positive emotions. Effects of the licking category (spontaneous, solicited), the animals’ basic activity (standing, lying) and the licked body region (head, neck, rest) were also considered. Two studies (A, B) were carried out in the same loose ...
Tópico(s): Meat and Animal Product Quality
2011 - Elsevier BV | Applied Animal Behaviour Science
Peter Saladin, Christoph Zenger,
Tópico(s): Sociology and Education Studies
1990 - Gütersloher Verlagshaus | Evangelische Theologie
Philipp Bitzenbauer, Sebastian Franz Höfler, Joaquin M. Veith, Bianca Winkler, Tim Zenger, Christoph Kulgemeyer,
Abstract Physics education research on explanatory videos has experienced a boost in recent years. Due to the vast number of explanatory videos available online, e.g. on YouTube, finding videos of high explaining quality is a challenging task for learners, teachers, and lecturers alike. Prior research on the explaining quality of explanatory videos on classical mechanics topics has uncovered that the surface features provided by YouTube (e.g. number of views or likes) do not seem to be suitable indicators ...
Tópico(s): Educational Strategies and Epistemologies
2023 - Springer Nature | International Journal of Science and Mathematics Education
Michael Bäder, Christoph Zenger,
Tópico(s): Quantum Computing Algorithms and Architecture
2006 - Springer Science+Business Media | Lecture notes in computer science
Victor Ganzha, Richard Liška, Mikhail Shashkov, Christoph Zenger,
A finite difference algorithm for solution of generalized Laplace equation on unstructured triangular grid is constructed by a support operator method. The support operator method first constructs discrete divergence operator from the divergence theorem and then constructs discrete gradient operator as the adjoint operator of the divergence. The adjointness of the operators is based on the continuum Green formulas which remain valid also for discrete operators. Developed method is exact for linear ...
Tópico(s): Soil, Finite Element Methods
2002 - | Selçuk journal of applied mathematics
Frank Günther, Andreas Krahnke, Markus Langlotz, Miriam Mehl, Markus Pögl, Christoph Zenger,
Tópico(s): Advanced Numerical Methods in Computational Mathematics
2004 - Springer Science+Business Media | Lecture notes in computer science
Minimal subadditive inclusion sets for the eigenvalues of matrices are constructed as numerical ranges based on a relation called parallelism which generalizes Bauer's dual vector pairs and Lumers semi-inner-product spaces. The corresponding sets of dissipative matrices are shown to be maximal convex cones of nonsingular matrices. The results are useful as a basis for an axiomatic definition of numerical ranges not restricted to normed algebras. The invariance of certain cones of dissipative matrices ...
Tópico(s): Advanced Topics in Algebra
1977 - Elsevier BV | Linear Algebra and its Applications