Hans-Georg Matuttis
| Department of Mechanical and Intelligent Systems Engineering | Professor |
| Cluster III (Fundamental Science and Engineering) | Professor |
| Fundamental Program for Advanced Engineering (Evening Course) | Professor |
| International Education Center | Professor |
Researcher Information
Field Of Study
Career
Research Activity Information
Paper
- A force–displacement relation based on the JKR theory for DEM simulations of adhesive particles
Jian Chen; Dominik Krengel; Daisuke Nishiura; Mikito Furuichi; Hans-Georg Matuttis
Powder Technology, Elsevier BV, 427, 118742-118742, Sep. 2023
Scientific journal - The Good, the Bad and the Ugly: droplet recognition by a “shootout”-heuristics
Hans-Georg Matuttis; Silvia Holler; Federica Casiraghi; Johannes Josef Schneider; Alessia Faggian; Rudolf Marcel Füchslin; Martin Michael Hanczyc
https://www.wivace2021.org, XV, 17 Sep. 2021, Peer-reviwed
International conference proceedings, English - Grid-algorithm improvements for dense suspensions of discrete element particles in finite element fluid simulations
Jan Mueller; Akira Kyotani; Hans-Georg Matuttis
Proceedings to Powders & Grains 2021, EPJ Web of Conferences, 249, 09006-1-09006-4, 2021, Peer-reviwed
International conference proceedings, English - Experimental study of particle shape dependence of avalanches inside a rotating drum
Jian Chen; Dominik Krengel; Hans-Georg Matuttis
Proceedings of Powders and Grains 2021, EPJ Web of Conferences, 249, 06001-1-06001-1, 2021, Peer-reviwed
International conference proceedings, English - Implementation of numerically exact Coulomb friction for discrete element simulations in three dimensions
Shouta Sakamaki; Dominik Krengel; Jan Mueller; Jian Chen; Hans-Georg Matuttis
Proceedings to Powders and Grains 2021, 249, 14005-1-14005-2, 2021, Peer-reviwed
International conference proceedings, English - Towards a Micromechanical Understanding of Landslides - Aiming at a Combination of Finite and Discrete Elements with Minimal Number of Degrees of Freedom
Jan Mueller; Akira Kyotani; Hans-Georg Matuttis
JAMP (Journal of applied Mathematics and Phyics), 87, 9, 1779-1798, Sep. 2020, Peer-reviwed
Scientific journal, English - Some basic ideas on friction
Dominik Krengel; Hans-Georg. Matuttis
to appear in Environmental Geotechnics, Themed Issue: Thermodynamics in Material Modelling and Geotechnical Design, 16 pages, 2019
International conference proceedings, English - Implementation of Static Friction for Many-Body Problems in Two Dimensions
Dominik Krengel; Hans-Georg Matuttis
Journal of the Physical Society of Japan, 87, 124402-1-124402-16, Dec. 2018, Peer-reviwed
Scientific journal, English - Comparing numerically exact and modelled static friction
Dominik Krengel; Hans-Georg Matuttis
EPJ Web of Conferences, EDP Sciences, 140, 15020, 1-4, 30 Jun. 2017, Peer-reviwed, Currently there exists no mechanically consistent "numerically exact" implementation of static and dynamic Coulomb friction for general soft particle simulations with arbitrary contact situations in two or three dimension, but only along one dimension. We outline a differential-algebraic equation approach for a "numerically exact" computation of friction in two dimensions and compare its application to the Cundall-Strack model in some test cases.
International conference proceedings, English - Stress-Strain diagrams for non-convex particles
Hans-Georg Matuttis; Masaki Nawa; Dominik Krengel
EPJ Web of Conferences, EDP Sciences, 140, 06005-1-06005-4, 30 Jun. 2017, Peer-reviwed, While most granular materials in nature and technology consist of non-convex particles, the majority of discrete element (DEM) codes are still only able to cope with convex particles, due to the complexity of the computational geometry and the occurrence of multiple contacts. We have reengineered a code for convex polygonal particles to model non-convex particles as rigidly connected clusters. Constricting non-convex particles along the symmetry axes by 30% leads to an increase of the materials strength of up to 50%.
International conference proceedings, English - The Effect of the Shape of Granular Particles on Density
Dominik Krengel; Wei Shen Cheng; Jian Chen; Hans-Georg Matuttis
Journal of the Physical Society of Japan, 84, 67065-1-67065-5, May 2015, Peer-reviwed
Scientific journal, English - Synergies from using Higher Order Symplectic Decompositions Both for Ordinary Differential Equations and Quantum Monte Carlo Methods
Hans-Georg Matuttis; Xiaoxing Wang
PROCEEDINGS OF THE INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014), AMER INST PHYSICS, 1648, 200002, 2015, Peer-reviwed, Decomposition methods of the Suzuki-Trotter type of various orders have been derived in different fields. Applying them both to classical ordinary differential equations (ODEs) and quantum systems allows to judge their effectiveness and gives new insights for many body quantum mechanics where reference data are scarce. Further, based on data for 6x6 system we conclude that sampling with sign (minus-sign problem) is probably detrimental to the accuracy of fermionic simulations with determinant algorithms.
International conference proceedings, English - OPTIMIZATION AND OPENMP PARALLELIZATION OF A DISCRETE ELEMENT CODE FOR CONVEX POLYHEDRA ON MULTI-CORE MACHINES
Jian Chen; Hans-Georg Matuttis
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 24, 2, 1350001 1-24, Feb. 2013, Peer-reviwed, We report our experiences with the optimization and parallelization of a discrete element code for convex polyhedra on multi-core machines and introduce a novel variant of the sort-and-sweep neighborhood algorithm. While in theory the whole code in itself parallelizes ideally, in practice the results on different architectures with different compilers and performance measurement tools depend very much on the particle number and optimization of the code. After difficulties with the interpretation of the data for speedup and efficiency are overcome, respectable parallelization speedups could be obtained.
Scientific journal, English - Granular acoustics of polyhedral particles
Wei Shen Cheng; Jian Chen; Hans-Georg Matuttis
AIP Conference Proceedings, 1542, 567-570, 2013, Peer-reviwed, Our previous time-of-flight studies with two-dimensional polygonal simulations and one-and three-dimensional experiments showed that the sound-velocity in granular materials in one and two dimensions is of the order of 10% of that of the bulk material, while in three dimensions with spherical beads, it is only of the order of one percent. The conclusion was that the force network in three dimensions leads to a reduction of the sound velocity compared to two dimensions. With our newly completed fully three dimensional discrete element method with polyhedral particles, we investigate the relation between particle shape, size dispersion and sound velocity. The force-law is able to reproduce the sound velocity of the bulk material for space-filling particle packings. We find that the sound velocities in polyhedral assemblies are about 3% to 5% of the bulk sound velocities. This means that the influence of the particle geometry on the contact is significant. Aggregates with particles with many surfaces show higher sound velocities than those with sharp edges. Additionally, solitonic waves were observed which propagated in front of the sound-waves, but only in a relatively short range. © 2013 AIP Publishing LLC.
International conference proceedings, English - Polygonal Particles in Fluids
Shi Han Ng; Hans-Georg Matuttis
POWDERS AND GRAINS 2013, AMER INST PHYSICS, 1542, 1138-1141, 2013, Peer-reviwed, For arbitrary convex polygonal discrete elements in a fluid in two dimensions, we have implemented a stable microscopic simulation method, i.e. the flow goes around the particles, not through them, as in macroscopic simulations. The incompressible fluid is modeled via the differential algebraic equation formulation for finite elements, so that the pressures are Lagrange parameters of the underlying constraint system. Granular particles are modeled with of a core and a wider shadow around the core: The particle interaction is via the shadow, in which fluid flow is allowed, while the core is an impenetrable boundary for the fluid. The simulation works for arbitrary volume rations, so that both fluid flowing through a granular pore-space as well as particles sinking in a fluid can be simulated. We investigate the collapse of a granular step with and without fluid.
International conference proceedings, English - Effect of the surrounding fluid on the compaction of granular materials by tapping: Slow dynamics made slower?
Shi Han Ng; Hans-Georg Matuttis
4TH INTERNATIONAL SYMPOSIUM ON SLOW DYNAMICS IN COMPLEX SYSTEMS: KEEP GOING TOHOKU, AMER INST PHYSICS, 1518, 372-378, 2013, Peer-reviwed, We investigate compaction due to tapping in two-dimensional granular columns computationally with the discrete element method (DEM) in two dimensions. We compare the compaction in dry granulates with the compaction of the system immersed in a viscous fluid. We use polygons as particle shapes, so that the resulting pore-space can be triangulated for a finite element method (FEM) for an incompressible fluid. We investigate the competition between a slowing-down of the dynamics due to the viscous forces of the fluid and the improved transmission of the tapping pulses through the fluid in the pore space. For the system immersed in water, the propagation of the shocks due to the tapping of the floor is faster than in the corresponding dry system. The center of mass of a nearly square system drops faster for the dry case than for immersed particles. For a system twice as high and half as wide, for the same vibration, for the dry system, the center of mass rises, while for the immersed particles there is hardly any change.
International conference proceedings, English - Simulating Free Boundaries in 2D FEM Flow-Simulation with Direct Time Integration of the Surface Velocities
Ng Shi Han; Hans-Georg Matuttis
Journal of Algorithms & Computational Technology, 7, 3, 287-300, 2013, Peer-reviwed
Scientific journal, English - Effect of the surrounding fluid on the compaction of granular materials by tapping: Slow dynamics made slower?
Shi Han Ng; Hans-Georg Matuttis
4TH INTERNATIONAL SYMPOSIUM ON SLOW DYNAMICS IN COMPLEX SYSTEMS: KEEP GOING TOHOKU, AMER INST PHYSICS, 1518, 372-378, 2013, We investigate compaction due to tapping in two-dimensional granular columns computationally with the discrete element method (DEM) in two dimensions. We compare the compaction in dry granulates with the compaction of the system immersed in a viscous fluid. We use polygons as particle shapes, so that the resulting pore-space can be triangulated for a finite element method (FEM) for an incompressible fluid. We investigate the competition between a slowing-down of the dynamics due to the viscous forces of the fluid and the improved transmission of the tapping pulses through the fluid in the pore space. For the system immersed in water, the propagation of the shocks due to the tapping of the floor is faster than in the corresponding dry system. The center of mass of a nearly square system drops faster for the dry case than for immersed particles. For a system twice as high and half as wide, for the same vibration, for the dry system, the center of mass rises, while for the immersed particles there is hardly any change.
International conference proceedings, English - The Fermionic Minus-Sign Problem for the Ground State, Revisited with Higher Order Suzuki-Trotter Decompositions
Xiaoxing Wang; Hans-Georg Matuttis
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 81, 10, 104002 1-17, Oct. 2012, Peer-reviwed, A theorem by Yoshida which states that the discretization error for the Suzuki-Trotter (ST) decomposition is one order smaller than for the corresponding approximated Hamiltonian has long been overlooked with grave consequences for the accuracy of algorithms which use decomposition schemes. In our error analysis for the ground state energy of the Hubbard Hamiltonian by the projector quantum Monte Carlo method, we have used various orders of ST-decompositions, including for the first time in this field, pseudo-symplectic methods. We show that higher order does not necessarily imply better convergence, and identify the condition to obtain good convergence with higher order ST-decompositions. For the first order ST-decomposition, the ground state energy does not converge to the values for numerical diagonalization, in agreement with Yoshida's theorem, which may have caused confusion in connection with the "fermionic sign problem". We show how the use of the sign of the fermion determinant is in fact a reweighing method which for the ground state energy violates some basic Monte Carlo properties (the Gaussian distribution of observables), in contrast to sampling without sign. Whether sampling with or without the sign deviates less from the exact ground state energy depends on the system parameters (interaction, filling) and on the test wave function, so sampling with sign gives not necessarily better or more physical than sampling without sign, a result which can be supported by arguments on the error compensation. We discuss the implications for related methods.
Scientific journal, English - Study of quasi two dimensional granular heaps
Jian Chen; Hans-Georg Matuttis
Theoretical and Applied Mechanics Japan, 60, 225-238, 2012, Peer-reviwed
Scientific journal, English - Two-dimensional microscopic simulation of granular particles in fluid
Shi Han Ng; Hans-Georg Matuttis
Theoretical and Applied Mechanics Japan, 60, 105-115, 2012
Scientific journal, English - Adaptive Mesh Generation for Two-Dimensional Simulation of Polygonal Particles in Fluid
Shi Han Ng; Hans-Georg Matuttis
Theoretical and Applied Mechanics Japan, 59, 323-333, 2011, Peer-reviwed
Scientific journal, English - Numerical irreversibility in energy-conserving many particle systems
Xiaoxing Wang; Hans-Georg Matuttis
Theoretical and Applied Mechanics Japan, 59, 309-321, 2011, Peer-reviwed
Scientific journal, English - Discrete Element Simulation for Polyhedral Granular Particles
Chen, J; Schinner, A; Matuttis, H.-G
Theoretical and Applied Mechanics Japan, 59, 335–346, 2011, Peer-reviwed
Scientific journal, English - Static Friction, Differential Algebraic Systems and Numerical Stability
Jian Chen; Alexander Schinner; Hans-Georg Matuttis
COMPUTER SIMULATIONS STUDIES IN CONDENSED MATTER PHYSICS XXI - PROCEEDINGS OF THE 21ST WORKSHOP, ELSEVIER SCIENCE BV, 6, 65-75, 2010, We show how Differential Algebraic Systems (Ordinary Differential Equations with algebraic constraints) in mechanics are affected by stability issues and we implement Lubich's projection method to reduce the error to practically zero. Then, we explain how the "numerically exact" implementation for static friction by Differential Algebraic Systems can be stabilized. We conclude by comparing the corresponding steps in the "Contact mechanics" introduced by Moreau. (C) 2010 Published by Elsevier Ltd.
International conference proceedings, English - Static Friction, Differential Algebraic Systems and Numerical Stability
Jian Chen; Alexander Schinner; Hans-Georg Matuttis
COMPUTER SIMULATIONS STUDIES IN CONDENSED MATTER PHYSICS XXI - PROCEEDINGS OF THE 21ST WORKSHOP, ELSEVIER SCIENCE BV, 6, 65-75, 2010, We show how Differential Algebraic Systems (Ordinary Differential Equations with algebraic constraints) in mechanics are affected by stability issues and we implement Lubich's projection method to reduce the error to practically zero. Then, we explain how the "numerically exact" implementation for static friction by Differential Algebraic Systems can be stabilized. We conclude by comparing the corresponding steps in the "Contact mechanics" introduced by Moreau. (C) 2010 Published by Elsevier Ltd.
International conference proceedings, English - Jian Chen, Lisa Watanabe, Hans-Georg Matuttis¤ and Hide Sakaguchi
History Dependence of the; Density Distribution in; Granular Heaps
Powders & Grains 2009, 1, Jul. 2009
International conference proceedings, English - History Dependence Of The Density Distribution On Granular Heaps
Jian Chen; Lisa Watanabe; Hans-Georg Matuttis; Hide Sakaguchi
POWDERS AND GRAINS 2009, AMER INST PHYSICS, 1145, 199-+, 2009, Peer-reviwed, In previous computational work by one of the authors, the pressure minimum under heaps was shown to result from the construction history. In this work we will show that the construction history is actually embedded in the average density of the granular material.
International conference proceedings, English - Simulation Of Polygonal Grains In A Finite-Element-Fluid
Yuuske Sakai; Jian Chen; Hans-Georg Matuttis
POWDERS AND GRAINS 2009, AMER INST PHYSICS, 1145, 1019-1022, 2009, Peer-reviwed, While many phenomena in granular materials can be treated with "dry" grains, in some applications the surrounding fluid plays a role. We show how a Discrete Element code with polygonal particles (to take into account shape effects from roughness and elongation) can be combined with a Finite-Element method of an incompressible Navier Stokes fluid.
International conference proceedings, English - Random-walk type model with fat tails for financial markets
Hans-Geors Matuttis
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 19, 7, 1017-1026, Jul. 2008, Starting from the random-walk model, practices of financial markers are included into the random-walk so that fat tail distributions like those in the high frequency data of the SP500 index are reproduced, though the individual mechanisms are modeled by normally distributed date. The incorporation of local correlation narrows the distribution for "frequent" events, whereas global correlations due to technical analysis leads to fat tails. Delay of market transactions in the trading process shifts the fat tail probabilities dowmwards. Such an inclusion of reactions to market fluctuations leads to mini-trends which are distributed with unit variance.
Scientific journal, English - Acoustic of sound propagation in granular materials in one, two, and three dimensions
Salah A. M. El Shourbagy; Shiro Okeda; Hans-Georg Matuttis
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 77, 3, 034606-1-034606-15, Mar. 2008, We investigate the sound velocity of assemblies of granular particles. Computationally, we investigate regular polygons with various corner numbers in two dimensions with the discrete element method and compare the results for large corner numbers with experiments on soft air-gun beads. The sound velocity for one-dimensional granular chains of spherical particles is about one order of magnitude less than the sound velocity of the bulk material, both in the simulation as well as in the experiment. For two-dimensional simulations, the results are comparable to that for one-dimensional chains, but vary with the packing. For the experiments in three dimensions, we find that the sound velocity is two orders of magnitude less than that of the bulk, or one order of magnitude less than that for one- or two-dimensional systems. This result is consistent with the group velocity reported by Liu and Nagel, but well below their reported "sound velocity". The latter was in all likelihood not a linear (amplitude-independent) sound wave but one for which the sound-velocity was already affected by non-linear effects, as we elaborate on experimental, theoretical and computational considerations.
Scientific journal, English - Numerical Solution of Ordinary Differential Equations for Modeling in Socio-Econo-Physics
H.-G. Matuttis; J. Chen
Lectures on Socio- and Econophysics, 1, 1, Sep. 2007, Peer-reviwed
International conference proceedings, English - Simulation of the dependence of the Bulk-Stress-Strain Relations of Granular Materials on the Particle Shape
Salah A. M. El Shourbagy; Shinichi Morita; Hans-Georg Matuttis
Journal of the physical society of Japan, 75, 10, 104602-1 - 104602-10, Aug. 2006
Scientific journal, English - 複雑粒体中における音響伝播の異方性
板橋洋平; H.-G. Matuttis
第１９回数値流体力学シンポジウム学会論文誌, 189, Dec. 2005
Research institution, Japanese - 複雑流体としての粉粒体：３次元相互作用のモデリングの提唱
諏訪光太; H.-G. Matuttis
第１９回数値流体力学シンポジウム学会論文誌, 91, Dec. 2005
Research institution, English - 二次元粉粒体中における応力伝播の測定
H.-G. Matuttis
Proceedings of 2005 Annual Meeting , Japan Society of Fluid Mechanics ( NAGARE Additional Volume), 日本流体力学会, 24, 40-40, Sep. 2005, Many Models have been proposed for the Stress-Propagation in Granular Materials, which all assume a "universal" behaviour independent of external parameters. Measurements (by Behringer et. al) up to now had been inconclusive. We present experimental results where we can show that the characteristics of the stress propagation in granular materials is not "universal" but depends on the fubric and ordering in the granular packing.
Research institution, Japanese - 次元および２次元における粉粒体中の音響伝播シミュレーション
Salah El Shourbagy; H.-G. Matuttis
Proceedings of 2005 Annual Meeting , Japan Society of Fluid Mechanics ( NAGARE Additional Volume), 24, 309, Sep. 2005
Research institution, English - Multicanonical simulations of the tails of the order-parameter distribution of the two-dimensional Ising model
R Hilfer; B Biswal; HG Mattutis; W Janke
COMPUTER PHYSICS COMMUNICATIONS, ELSEVIER SCIENCE BV, 169, 1-3, 230-233, Jul. 2005, Peer-reviwed, We report multicanonical Monte Carlo simulations of the tails of the order-parameter distribution of the two-dimensional Ising model for fixed boundary conditions. Clear numerical evidence for "fat" stretched exponential tails is found below the critical temperature, indicating the possible presence of fat tails at the critical temperature. (c) 2005 Elsevier B.V. All rights reserved.
Scientific journal, English - Nonexistence of d-wave-superconductivity in the quantum Monte Carlo simulation of the Hubbard model
HG Matuttis; N Ito
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 16, 6, 857-866, Jun. 2005, For the existence of d-wave-superconductivity in the Hubbard model, previous quantum Monte Carlo results by other authors, which showed a power law increase of the d-wave susceptibility, seem to contradict a recently published theorem. We show those quantum Monte Carlo calculations were numerically contaminated, analyze the numerical problem and propose a numerically more stable computing scheme.
Scientific journal, English - Structure formation in a binary monolayer of dipolar particles
Varga, I; H Yamada; F Kun; HG Matuttis; N Ito
PHYSICAL REVIEW E, AMER PHYSICAL SOC, 71, 5, 051405(1-7), May 2005, Peer-reviwed, We propose an experimental technique for an easy to control realization of a binary dipolar monolayer where the two components have oppositely oriented dipole moments constrained perpendicular to the plane of motion without the application of an external field. The experimental setup ensures that hydrodynamic effects do not play a crucial role in the structure formation, the particles move deterministically due to the dipole-dipole interaction. At low concentrations, cluster-cluster aggregation occurs with chainlike morphologies, while at high concentration the particles self-assemble into various types of binary crystal lattices, in good agreement with the theoretical predictions. The structures formed by the particles are found to be sensitive to external perturbations due to the central interparticle forces, however, static friction arising at the contact surface of particles can increase the stability compared to systems with only viscous friction.
Scientific journal, English - Simple stochastic modeling for fat tails in financial markets
H.-G. Matuttis
rd Nikkei Econophysics Symposium 2005, Ed. H. Takayasu, "Practical Fruits of Econophysics", 178-182, 2005, Peer-reviwed
International conference proceedings, English - Angle of repose for two-dimensional particle aggregates from particle-size and -shape
Salah A. M. El Shourbagy; Hans-Georg Matuttis
Proceedings of the 5th international conference "Powders&Grains 2005", ed. Ramon Garcia-Roji, Hans J. Herrmann, Sean McNamara, 1289-1293, 2005, Peer-reviwed
International conference proceedings, English - Shape segregation in granular materials: A game of Go where shape beats size and buoyancy
Hans-Georg Matuttis; Seiji Omata; Osamu Sano
Proceedings of the 5th international conference "Powders&Grains 2005", ed. Ramon Garcia-Roji, Hans J. Herrmann, Sean McNamara, 1349-1353, 2005, Peer-reviwed
International conference proceedings, English - Density and size segregation in deposits of pyroclastic flow
NK Mitani; HG Matuttis; T Kadono
GEOPHYSICAL RESEARCH LETTERS, AMER GEOPHYSICAL UNION, 31, 15, Aug. 2004, The main portion in the deposits of pyroclastic flow shows various characteristic features such as density and size segregation of large fragments in the vertical direction. To understand the mechanism which produces these features, we numerically study granular flows on an inclined rough surface with impurities that are different in density and size from the matrix particles. The simulation shows the occurrence of density and size segregation of large impurities, and the impurities finally concentrate at the top and the bottom. Based on these results, we discuss the mechanism of the segregation. It is found that the behavior of impurities is governed by gravity, buoyancy and the viscosity of the randomly moving matrix.
Scientific journal, English - Vibration-induced compaction in elongated vessels
Hans-Georg Matuttis; Takumi Kinouchi; Hide Sakaguchi
Mathematical Aspects of Complex Fluids IV, RIMS Kokyoroku series, 1413, Feb. 2004 - Multicanonical Monte Carlo study and analysis of tails for the order-parameter distribution of the two-dimensional Ising model
R Hilfer; B Biswal; HG Mattutis; W Janke
PHYSICAL REVIEW E, AMER PHYSICAL SOC, 68, 4, Oct. 2003, The tails of the critical order-parameter distribution of the two-dimensional Ising model are investigated through extensive multicanonical Monte Carlo simulations. Results for fixed boundary conditions are reported here, and compared with known results for periodic boundary conditions. Clear numerical evidence for "fat" stretched exponential tails exists below the critical temperature, indicating the possible presence of fat tails at the critical temperature. Our work suggests that the true order-parameter distribution at the critical temperature must be considered to be unknown at present.
Scientific journal, English - Modeling Friction in Granular Materials
H.-G. Matuttis; A. Schinner
Bussei Kenkyuu, 43, 2, Jul. 2003
Scientific journal - Shape segregation for bidisperse mixtures of ellipses in two dimensions
HG Matuttis; N Ito; H Watanabe
TRAFFIC AND GRANULAR FLOW'01, SPRINGER-VERLAG BERLIN, 455-460, 2003, Whereas size segregation is a fairly common phenomenon in granular material research, up to now shape segregation was has not been observed. We present simulations of bidisperse shaped (elliptic and round) granular particle systems which exhibit a demixing of round and elongated particles. The effect is not only controlled by the particle elongation, but also by the Coulomb friction coefficient in the system.
International conference proceedings, English - Outline for a simulation method for volcanic eruptions using DEM
K. Kagami; N. K. Mitani; N. Ito; T. Koyaguchi
火山爆発のダイナミックス、文部科学省科学研究費特定領域研究, 422, 2003
English - Quantum computing simulation using the auxiliary field decomposition
K Fischer; HG Matuttis; S Yukawa; N Ito
COMPUTER SIMULATION STUDIES IN CONDENSED-MATTER PHYSCIS XVI, SPRINGER-VERLAG BERLIN, 95, 79-85, 2003
International conference proceedings, English - Auxiliary field methods for the simulation of quantum computation circuits
HG Matuttis; K Fischer; N Ito; M Ishikawa
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 13, 7, 917-929, Sep. 2002, One obstacle in the simulation of quantum circuits is the high dimension of the Hilbert space. Using auxiliary field decompositions known from many-particle simulation, we can transform the mathematical description of the quantum circuit into a combination low-dimensional product states which can be sampled using Monte Carlo techniques. We demonstrate the method using Simon's algorithm for the detection of the period of a function.
Scientific journal, English - Quantum-statistical simulations for quantum circuits
K Fischer; HG Matuttis; N Ito; M Ishikawa
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 13, 7, 931-945, Sep. 2002, Using a Hubbard-Stratonovich like decomposition technique, we implemented simulations for the quantum circuits of Simon's algorithm for the detection of the periodicity of a function and Shor's algorithm for the factoring of prime numbers on a classical computer. Our approach has the advantage that the dimension of the problem does not grow exponentially with the number of qubits.
Scientific journal, English - Advances in the investigation of the minus sign problem for the fermionic case
HG Matuttis; N Ito
COMPUTER SIMULATION STUDIES IN CONDENSED-MATTER PHYSICS XIV, SPRINGER-VERLAG BERLIN, 89, 194-199, 2002, Recent results in the investigation of the quantum Monte Carlo method for the Hubbard model using auxiliary fields revealed that the minus-sign problem for the fermionic case may be much more benign than conclusions in earlier studies indicated.
International conference proceedings, English - Particle simulation of cohesive granular materials
HG Matuttis; A Schinner
INTERNATIONAL JOURNAL OF MODERN PHYSICS C, WORLD SCIENTIFIC PUBL CO PTE LTD, 12, 7, 1011-1021, Sep. 2001, We present two-dimensional molecular dynamics simulations of cohesive regular polygonal particles. The cohesive part of the force-law for the particle-particle interaction is validated by the agreement with existing experimental data. We investigate microscopic parameters, which axe not accessible to experiments such as contact length, raggedness of the surface and correlation time. With increasing cohesion, the particles move in clusters for long times.
Scientific journal, English - Some findings on the minus-sign problem for the Hubbard model in the projector quantum Monte Carlo method
HG Matuttis; N Ito
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, 70, 6, 1519-1522, Jun. 2001, The quantum Monte Carlo method for the Hubbard model using the Hubbard-Stratonovich transformation is reexamined. It is observed that the value of the ground state energy for a 3 x 2 and 4 x 4 system is estimated correctly by ignoring the minus-sign of the negative sampling weight appearing in the simulation using the projector method. It is also observed that the average of sign is positive and the correlation between the energy and the sign is weak for these systems. The reasons why the ground state energy is estimated correctly is given on a phenomenological base.
Scientific journal, English - Rotational dynamics of magnetic particles in suspensions
C Scherer; HG Matuttis
PHYSICAL REVIEW E, AMER PHYSICAL SOC, 63, 1, Jan. 2001, An approach for the rotational dynamics of magnetic particles and their magnetic moments, in fluid suspensions, is developed. A possible application is to magnetic resonance in ferrofluids. Based on a generalized Lagrangian formulation for the equations of motion of the particle, we introduce its interaction with the solvent fluid via dissipative and random noise torques, as well as the interaction between the particle and its magnetic moment, treated as an independent physical entity and characterized by three generalized coordinates: its two polar angles and its modulus. In the appropriate limits, it reduces to the cases of superparamagnetic particles or nonsuperparamagnetic (blocked magnetic moments) particles. It is also indicated how the dynamic complex susceptibility may be calculated from the equations of motion, and as an example the effect of the particles inertia on the susceptibility is numerically evaluated for some arbitrary values of the parameters.
Scientific journal, English - Fractal space, cosmic strings and spontaneous symmetry breaking
J Argyris; C Ciubotariu; HG Matuttis
CHAOS SOLITONS & FRACTALS, PERGAMON-ELSEVIER SCIENCE LTD, 12, 1, 1-48, Jan. 2001, The present paper is conceived within the framework of El Naschie's fractal-Cantorian program and proposes to develop a model of the fractal properties of spacetime. We show that, starting from the most fundamental level of elementary particles and rising up to the largest scale structure of the Universe, the fractal signature of spacetime is imprinted onto matter and fields via the common concept for all scales emanating from the physical spacetime vacuum fluctuations. The fractal structure of matter, field and spacetime (i.e. the nature and the Universe) possesses a universal character and can encompass also the well-known geometric structures of spacetime as Riemannian curvature and torsion and includes also, deviations from Newtonian or Einsteinian gravity (e.g. the Rossler conjecture). The leitmotiv of the paper is generated by cosmic strings as a fractal evidence of cosmic structures which are directly related to physical properties of a vacuum slate of matter (VSM). We present also some physical aspects of a spontaneous breaking of symmetry and the Higgs mechanism in their relation with cosmic string phenomenology. Superconducting cosmic strings and the presence of cosmic inhomogeneities can induce to cosmic Josephson junctions (weak links) along a cosmic string or in connection with a cosmic string (self) interactions and thus some intermittency routes to a cosmic chaos can be explored. The key aspect of fractals in physics and of fractal geometry is to understand why nature gives rise to Fractal structures. Our present answer is: because a fractal structure is a manifestation of the universality of self-organisation processes, as a result of a sequence of spontaneous symmetry breaking (SSB). Our conclusion is that it is very difficult to prescribe a certain type of fractal within an empty spacetime. Possibly, a random fractal (like a Brownian motion) characterises the structure of free space. The presence of matter will decide the concrete form of fractalisation. But, what does it mean the presence of matter? Can there exist a spacetime without matter or matter without spacetime? Possibly not, but consider on the other hand a space far removed from usual matter, or a space containing isolated small particles in which a very low density matter can exist. Very low density matter might be influenced by a fractal structure of space, for example in the sense that it is subject also to fluctuations structured by random fractals. Diffraction and diffusion experiments in an empty space and very low density matter could provide evidence of a fractal structure of space. However, at very high (Planck) densities, and a spacetime in which fluctuations represent also the source of matter and fields (which is very resonable within the context of a quantum gravity), we can assert that Einstein's dream of geometrising physics and El Naschie's hope to prove the fractalisation (or Cantorisation) of spacetime are fully realised. (C) 2000 Elsevier Science Ltd. All rights reserved.
Scientific journal, English - History-dependent structure in granular piles
A Schinner; HG Mattutis; T Akiyama; J Aoki; S Takahashi; KM Aoki; K Kassner
POWDERS AND GRAINS 2001, A A BALKEMA PUBLISHERS, 499-502, 2001, The pressure distribution under heaps has found to be dependent on the building history of the heap both in experiments and in simulations. Up to now, theoretical models and analysis assume that the packing of the heap is homogeneous. We show new experimental and simulational results which indicate that the packing is inhomogeneous and that this packing property is likely causing the pressure minimum under the heap.
International conference proceedings, English - Vectorizable overlap computation for ellipse-based discrete element method
HG Matuttis; N Ito; H Watanabe; KM Aoki
POWDERS AND GRAINS 2001, A A BALKEMA PUBLISHERS, 173-176, 2001, Ellipse shaped particles offer a wider variety of modellization for granular materials and complex fluids. Nevertheless, the contact and intersection detection for ellipses on the computer is a complicated task. Direct implementations of analytic approaches are not simple because the problem is numerically ill-conditioned. This article gives a new algorithm which allows a data-parallel computation of the ellipse intersection points for many-body simulations.
International conference proceedings, English - Behandlung des Schotters als Vielkoerpersystem mit wechselnden Bindungen
Holger Kruse; Karl Popp; Hans-Georg Matuttis; Alexander Schinner
Der Eisenbahningenieur, 52, 2, 2001
English - Discrete element simulations of dense packings and heaps made of spherical and non-spherical particles
HG Matuttis; S Luding; HJ Herrmann
POWDER TECHNOLOGY, ELSEVIER SCIENCE SA, 109, 1-3, 278-292, Apr. 2000, The discrete element method (DEM) in the simulation of static packings allows one to investigate the behavior of granular materials by modeling the forces on the particle level. No macroscopic parameters like the angle of repose enter the simulation, but they can be extracted as a result of the particle properties like friction, roughness or shape. One of the issues of static packings recently discussed is the stress distribution under granular heaps. This problem is used to highlight the possibilities of modeling at the particle level using DEM. Phenomena like arching or stress-chains are observed even for spherical particles in a regular pile in the absence of friction if the bottom is rough. The situation does not change much if polygonal, frictional particles are used without disturbing the regular piling. For more realistic situations, when the pile is built by pouring grains from above, the packing and the stresses are influenced by the creation history. The more eccentric the polygons are, the more pronounced a dip is observed in the vertical stress under the apex of the sand-pile. (C) 2000 Elsevier Science S.A. All rights reserved.
Scientific journal, English - Molecular dynamics simulation of cohesive granular materials
A Schinner; HG Matuttis
TRAFFIC AND GRANULAR FLOW'99, SPRINGER-VERLAG BERLIN, 505-510, 2000
International conference proceedings, English - Towards a micromechanic understanding of the pressure distribution under heaps
lexander Schinner; Hans-Georg Mattutis; Tetsuo Akiyama; Junya Aoki; Satoshi Takahashi; Keiko M. Aoki; Klaus Kassner
Proceedings of RIMS Symposium on Mathematical Aspects of Complex Fluids II, RIMS Kokyoroku series, 1188, 2000
English - Influence of the geometry on the pressure distribution of granular heaps
Hans-Georg Matuttis; Alexander Schinner
Granular Matter, 1, 4, 1999
English - The effect of particle shape and friction on the stresses in heaps of granular media in Friction
H.-G. Matuttis; S. Luding
Friction, Arching and Contact Dynamics, edited by D. E. Wolf and P. Grassberger, 1997
International conference proceedings, English - The effect of interaction laws on the stresses in frictionless granular media
S. Luding; H; G. Matuttis
Friction, Arching and Contact Dynamics, edited by D. E. Wolf and P. Grassberger, 1997
English - Simulation of the pressure distribution under a two dimensional heap of polygonal particles
H. -G. Matuttis
Granular Matter, 1, 2, 83-91, 1997
English - Quantum Monte Carlo evidence for d-wave pairing in the two-dimensional Hubbard model at a van Hove singularity
T Husslein; Morgenstern, I; DM Newns; PC Pattnaik; JM Singer; HG Matuttis
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 54, 22, 16179-16182, Dec. 1996, We implement a quantum Monte Carlo calculation for a repulsive Hubbard model with nearest- and next-nearest-neighbor hopping interactions on clusters up to 12 x 12. A parameter region where the Fermi level lies close to the van Hove singularity at the saddle points in the bulk band structure is investigated. A pairing tendency in the d(x2-y2), symmetry channel, but no other channel, is found. Estimates of the effective pairing interaction show that it is close to the value required for a 40 K superconductor. Finite-size scaling compares with the attractive Hubbard model.
Scientific journal, English - From BCS-like superconductivity to condensation of local pairs: A numerical study of the attractive Hubbard model
JM Singer; MH Pedersen; T Schneider; H Beck; HG Matuttis
PHYSICAL REVIEW B, AMERICAN PHYSICAL SOC, 54, 2, 1286-1301, Jul. 1996, We investigate the two-dimensional attractive Hubbard model with quantum Monte Carlo techniques to reveal the crossover from a BCS-type superconductivity in the weak-coupling regime to a superconductivity properly described by a Bose-Einstein condensation (BEC) of local, preformed pairs. The crossover from BCS to BEC is particularly well exposed in the temperature dependence of both the spin susceptibility and the double occupancy, as well as by the appearance of a pseudogap in the density of states far above T-c. These features are also mirrored in the shape of the specific-heat peak around T-c, the separation of the temperature regimes where pair formation and their condensation occur, and in the transfer of spectral weight from the single-particle excitation branch to a pair band in the normal state.
Scientific journal, English - DENSITY-OF-STATES IN THE T'-HUBBARD MODEL - EXACT DIAGONALIZATION RESULTS
W FETTES; MORGENSTERN, I; T HUSSLEIN; HG MATUTTIS; JM SINGER; C BAUR
JOURNAL DE PHYSIQUE I, EDITIONS PHYSIQUE, 5, 4, 455-464, Apr. 1995, We calculated the density of states in a Hubbard model with nearest and next nearest neighbour hopping. Using an exact diagonalisation technique, we examined this model in a wide area of parameters. The density of states was calculated for different fillings and for positive and negative interaction U. The additional hopping to the next nearest neighbour sites has different effects on the gap between the particle and hole spectrum compared to the pure Hubbard model.
Scientific journal, English - EFFICIENT PARALLELIZATION OF THE 2D SWENDSEN-WANG ALGORITHM
R HACKL; HG MATUTTIS; JM SINGER; T HUSSLEIN; MORGENSTERN, I
PHYSICA A, ELSEVIER SCIENCE BV, 212, 3-4, 261-276, Dec. 1994, We established a fast Swendsen-Wang algorithm for the two-dimensional Ising model on parallel computers with a high efficiency. On an Intel paragon with 140 processors we reached spin update times of only 14 ns with an efficiency of 89%. This algorithm was used to examine the non-equilibrium relaxation of magnetization and energy in large Ising systems of a size up to 17920 x 17920 spins. Nevertheless we observed still a strong finite-size effect for the magnetization. We assume both magnetization and energy decay to behave like (t + DELTA)-lambda(e)-bt in an infinitely large system. Thus, for long times magnetization and energy show an exponential, asymtotic time-dependence, implying a critical dynamic exponent z of zero.
Scientific journal, English - 3D ISING-MODEL WITH SWENDSEN-WANG DYNAMICS - A PARALLEL APPROACH
M BAUERNFEIND; R HACKL; HG MATUTTIS; J SINGER; T HUSSLEIN; MORGENSTERN, I
PHYSICA A, ELSEVIER SCIENCE BV, 212, 3-4, 277-298, Dec. 1994, We propose an efficient parallel implementation of the Swendsen-Wang algorithm for a 3D Ising system. A modified relaxation method was used for the parallelization. The simulations were performed on the Intel Paragon. We discuss the implementation in detail.
Scientific journal, English - SPIN-SPIN CORRELATIONS IN THE TT'-HUBBARD MODEL
T HUSSLEIN; DM NEWNS; HG MATTUTIS; PC PATTNAIK; MORGENSTERN, I; JM SINGER; W FETTES; C BAUR
JOURNAL DE PHYSIQUE I, EDITIONS PHYSIQUE, 4, 11, 1573-1576, Nov. 1994, We present calculations of the tt'-Hubbard model using Quantum Monte Carlo techniques. The parameters are chosen so that the van Hove Singularity in the density of states and the Fermi level coincide. We study the behaviour of the system with increasing Hubbard interaction U. Special emphasis is on the spin-spin correlation (SSC). Unusual behaviour for large U is observed there and in the momentum distribution function (n(q)).
English - EXPERIENCES WITH REENGINEERING AND PARALLELIZING A HIGH-T(C) SUPERCONDUCTIVITY CODE
U KLEIS; JM SINGER; MORGENSTERN, I; T HUSSLEIN; HG MATUTTIS
PARALLEL COMPUTING, ELSEVIER SCIENCE BV, 20, 3, 399-407, Mar. 1994, Motivated by experiments on high-T(c) superconducting compounds and made possible by the power of present day supercomputers, a number of researchers have used the Quantum Monte Carlo method to gain more insight into Hubbard-like many particle models.
We used the Projector Quantum Monte Carlo method (PQMC) [1,2] as a computational technique for studying the physical properties of many-electron and quantum-spin systems.
This review gives a survey of the algorithms and techniques as well as of the methods to implement the PQMC scheme on modem parallel computers like the Intel Hypercube or IBM RS/6000 workstation clusters.
In order to study systems of larger size or with more complex interactions, increasingly large amounts of computational power are required.
Although based on one particular algorithm, we believe that our results should interest simulators with quite different algorithms and other parallel architectures as well.
English - Virtuelle Parallelrechner
J.M.Singer; H.-G.Matuttis
Unix open, 8, 9, 1994
English - Numerical simulations of models for high-Tc superconductors
I. Morgenstern; W. Fettes; T. Husslein; C. Baur; H.-G. Matuttis; J.M. Singer
Proceedings of the 6th Joint EPS-APS International Conference on Physics Computing, Eds:R. Gruber, M. Tomassini, European Physical Society, 1994
English - NUMERICAL-SIMULATION OF HIGH-TEMPERATURE SUPERCONDUCTORS
MORGENSTERN, I; JM SINGER; T HUSSLEIN; HG MATUTTIS
MATERIALS AND CRYSTALLOGRAPHIC ASPECTS OF HT(C)-SUPERCONDUCTIVITY, KLUWER ACADEMIC PUBL, 263, 331-351, 1994
International conference proceedings, English - Virtuelle Parallelrechner
J.M.Singer; H.-G.Matuttis
Unix open, 8, 9, 1994
English - PARALLELIZATION OF THE 2D SWENDSEN-WANG ALGORITHM
R HACKL; HG MATUTTIS; JM SINGER; T HUSSLEIN; MORGENSTERN, I
INTERNATIONAL JOURNAL OF MODERN PHYSICS C-PHYSICS AND COMPUTERS, WORLD SCIENTIFIC PUBL CO PTE LTD, 4, 6, 1117-1130, Dec. 1993, We implemented a parallel Swendsen-Wang algorithm for a 2D Ising system without magnetization in a host-node programming model. The simulations were performed on the Intel Hypercube IPSC/860. Our maximum number of updates/s on 32 nodes 1st three times as high as in the implementation by Stauffer and Kertesz on the same machine. With 32 processors we reach half the speed of the simulations by Tamayo and Flanigan on 256 nodes of a CM5. We discuss the non-equilibrium relaxation for the energy and the magnetization.
Scientific journal, English - PARALLELIZATION OF THE 2D SWENDSEN-WANG ALGORITHM
R HACKL; HG MATUTTIS; JM SINGER; T HUSSLEIN; MORGENSTERN, I
INTERNATIONAL JOURNAL OF MODERN PHYSICS C-PHYSICS AND COMPUTERS, WORLD SCIENTIFIC PUBL CO PTE LTD, 4, 6, 1117-1130, Dec. 1993, We implemented a parallel Swendsen-Wang algorithm for a 2D Ising system without magnetization in a host-node programming model. The simulations were performed on the Intel Hypercube IPSC/860. Our maximum number of updates/s on 32 nodes 1st three times as high as in the implementation by Stauffer and Kertesz on the same machine. With 32 processors we reach half the speed of the simulations by Tamayo and Flanigan on 256 nodes of a CM5. We discuss the non-equilibrium relaxation for the energy and the magnetization.
Scientific journal, English - DOUBLE-LAYER HUBBARD-MODEL - OFF-DIAGONAL LONG-RANGE ORDER IN THE NODELESS D-WAVE CHANNEL
MORGENSTERN, I; T HUSSLEIN; JM SINGER; HG MATUTTIS
JOURNAL DE PHYSIQUE I, EDP SCIENCES S A, 3, 4, 1043-1051, Apr. 1993, We report on a numerical study of the double layer Hubbard model describing the CuO2 sheets in the high-T(c) oxides. For the simulation we employed the projector quantum Monte Carlo method (PQMC) to study the ground state properties of this correlated electron system. Our results provide evidence for off-diagonal long range order in the nodeless d-wave channel. The implications with respect to possible mechanisms for high-T(c) superconductivity in oxides in combination which phononic booster mechanisms are discussed.
Scientific journal, English - QUANTUM MONTE-CARLO SIMULATIONS OF THE APEX-OXYGEN-MODEL
JM SINGER; T HUSSLEIN; MORGENSTERN, I; HG MATUTTIS
PHYSICS COMPUTING '92, WORLD SCIENTIFIC PUBL CO PTE LTD, 465-467, 1993
International conference proceedings, English - NUMERICAL-SIMULATION OF THE DOUBLE-LAYER HUBBARD-MODEL
MORGENSTERN, I; T HUSSLEIN; JM SINGER; HG MATUTTIS
JOURNAL DE PHYSIQUE II, EDITIONS PHYSIQUE, 2, 8, 1489-1493, Aug. 1992, We have carried out Quantum Monte Carlo studies to investigate the double layer Hubbard model using the groundstate projector formalism. Evidence for off diagonal long range order in the nodeless d-wave pairing channel is provided. It is emphasized that the Projector Quantum Monte Carlo method has the potential to detect superconducting mechanisms in strongly correlated electron systems, which are not treatable by standard analytic methods. The Monte Carlo technique provides useful information about systems much larger than those accessible for exact diagonalization methods.
Scientific journal, English
MISC
- Deutsche Forscher Betreuen Deutsche Studierende
Hans-Georg Matuttis
Apr. 2016, Neues vom Club (ドイツ語圏日本学術振興会研究者同窓会の雑誌）, 62, 1, 6-6, German, Others - Wissenschaftlicher Gesprächskreis am 20.5.2015 im DAAD Büro Tōkyō
Hans-Georg Matuttis
Jun. 2015, Neues vom Club イツ語圏日本学術振興会研究者同窓会の雑誌, 59, 2, 12-12, German, Others - Understanding the Discrete Element Method: Simulation of Non-Spherical Particles for Granular and Multi-body Systems
Hans-Georg Matuttis; Jian Chen
Gives readers a more thorough understanding of DEM and equips researchers for independent work and an ability to judge methods related to simulation of polygonal particles. Introduces DEM from the fundamental concepts (theoretical mechanics and solidstate physics), with 2D and 3D simulation methods for polygonal particles. Provides the fundamentals of coding discrete element method (DEM) requiring little advance knowledge of granular matter or numerical simulation. Highlights the numerical tricks and pitfalls that are usually only realized after years of experience, with relevant simple experiments as applications. Presents a logical approach starting withthe mechanical and physical bases,followed by a description of the techniques and finally their applications. Written by a key author presenting ideas on how to model the dynamics of angular particles using polygons and polyhedral. Accompanying website includes MATLAB-Programs providing the simulation code for two-dimensional polygons. Recommended for researchers and graduate students who deal with particle models in areas such as fluid dynamics, multi-body engineering, finite-element methods, the geosciences, and multi-scale physics., Wiley Blackwell, 23 Jun. 2014, Understanding the Discrete Element Method: Simulation of Non-Spherical Particles for Granular and Multi-body Systems, 1-456, English, Others, 84927580012 - 28aAJ-5 Rheology of Fluid-Particle mixtures
Ng Shi Han; Matuttis Hans-Georg
The Physical Society of Japan (JPS), 05 Mar. 2014, Meeting abstracts of the Physical Society of Japan, 69, 1, 315-315, English, 1342-8349, 110009834683, AA11439205
Books and other publications
- Understanding the Discrete Element Method: Simulation of Non-Spherical Particles for Granular and Multi-body Systems
Hans-Georg Matuttis; Jian Chen
Textbook, English, Joint work, Wiley, Apr. 2014 - Quantum Monte Carlo Investigations for the Hubbard Model
H.-G. Matuttis; I. Morgenstern
English, Computational Physics, eds. Karl Heinz Hoffmann, Michael Schreiber (Eds.), 1996
Lectures, oral presentations, etc.
- Stabilization of static friction in constraint mechanics
Hans-Georg Matuttis; Mitsutoshi Sato; Dominik Krengel; Jian Chen
Oral presentation, English, Statphys28
08 Aug. 2023 - Micromechanic simulation of two-dimensional barchan dunes
Pawel Deren; Jan Mueller; Kodai Tamano; Hans-Georg Matuttis
Oral presentation, English, STATPHYS28
08 Aug. 2023 - Dimensionality effects in granulates under biaxial compression
Dominik Krengel; Yuki Shimizu; Jian Chen; Hans-Georg Matuttis
Poster presentation, Statphys28
07 Aug. 2023 - Simulation of underwater barchans with a combined Finite Element and Discrete Element Method
Pawel Deren; Jan Mueller; Kodai Tamano; Hans-Georg Matuttis
English
07 Aug. 2023 - Adaptive remeshing for a finite element simulation with discrete elements
Kodai Tamano; Jan Mueller; Hans-Georg Matuttis
Poster presentation, English, 34th IUPAP Conference on Computational Physics（CCP2023）
07 Aug. 2023 - Tree Code Based Neighborhood Algorithms for DEM
Yuki Watanabe; Dominik Krengel; Hans-Georg Matuttis
Oral presentation, English, CCP2023 - 34th IUPAP Conference on Computational Physics
05 Aug. 2023 - Discrete Element Simulations from two-dimensions with polygons to three dimensions with rods
Yuki Shimizu; Hans-Georg Matuttis; Dominik Krengel; Jian Chen
Oral presentation, English, WCCM2022 15th World Congress on Computational Mechanics, International conference
10 Aug. 2022 - Numerical stabilization for the constraint formulation of many-body-many-contact Coulomb friction
Hans-Georg Matuttis; Keita Shinohara; Dominik Krengel; Jian Chen; Jan Mueller
Oral presentation, English, WCCM2022 15th World Congress on Computational Mechanics, International conference
10 Aug. 2022 - Avalanching of variously shaped DEM particles in a rotating drum
Dominik Krengel; Hans-Georg Matuttis; Ryota Shiyake; Mamoru Kikumoto
Oral presentation, English, WCCM2022 15th World Congress on Computational Mechanics, International conference
01 Aug. 2022 - Development of a Plate Discrete Element Method: Geometry and Kinematics
Jian Chen; Hans-Georg Matuttis
Oral presentation, English, The 13th International Conference on Computational Methods (Virtual), International conference
26 Jun. 2022 - The Good, the Bad and the Ugly: droplet recognition by a “shootout”-heuristics
Hans-Georg Matuttis
Oral presentation, English, WIVACE 2021 XV International Workshop on Artificial Life and Evolutionary Computation, International conference
17 Sep. 2021 - Implementation of numerically exact Coulomb friction for discrete element simulations in three dimensions
Shouta Sakamaki; Dominik Krengel; Jan Mueller; Jian Chen; Hans-Georg Matuttis
Oral presentation, English, Proceedings of Powders and Grains, EPJ Web of Conferences, Hans-Georg Matuttis, Argentine / ZOOM, International conference
21 Jul. 2021 - Grid-algorithm improvements for dense suspensions of discrete element particles in finite element fluid simulations
Jan Mueller; Akira Kyotani; Hans-Georg Matuttis
Poster presentation, English, Powders and Grains 2021, EPJ Web of Conferences, Jan Mueller, International conference
Jul. 2021 - Experimental study of particle shape dependence of avalanches inside a rotating drum
Jian Chen; Dominik Krengel; Hans-Georg Matuttid
Poster presentation, English, EPJ Web of Conferences, Proceedings of Powders and Grains, International conference
Jul. 2021 - Graded FEM-Meshes for Improved Accuracy and Performance
Mueller Jan; 泉 伊智郎; Matuttis Hans-Georg
Oral presentation, Japanese, 第32回数値流体力学シンポジウム, Domestic conference
13 Dec. 2019 - On the origin of modern physics in the -dark- middle ages
Hans-Georg Matuttis
Oral presentation, English, 8th Meeting of the JSPS-Club in Japan, Domestic conference
07 Oct. 2019 - 漏斗内部の粉体の流れと詰まりのシミュレーション
坂牧聖太; Dominik Krengel; 篠原啓太; Matuttis Hans-Georg
Oral presentation, Japanese, 日本流体力学会, Domestic conference
19 Sep. 2019 - 加振による液状化現象下における微小粒子間の流れのシミュレーション
後藤大輝; 京谷 在; Mueller Jan; Matuttis Hans-Georg
Oral presentation, Japanese, 日本流体力学会 年会２０１９, Domestic conference
15 Sep. 2019 - 粘性摩擦の働く平面上を転がり運動する楕円体のシミュレーションと実験
森本輝織; 野上歩; Dominik Krengel; Hans-Georg Matuttis
Oral presentation, Japanese, 日本流体力学会 年会２０１９, Domestic conference
15 Sep. 2019 - FEM-Simulation with graduated meshes for particle agglomerations in fluids
Hans-Georg Matuttis; Ichiro Izumi; Jan Mueller
Oral presentation, English, 日本流体力学会 年会２０１９, Domestic conference
14 Sep. 2019 - Expanding P2P1 FEM Elements with Third Order Bubbles for Simulating Many Particles in Fluids
Jan Mueller; Hans-Georg Matuttis
Oral presentation, English, 日本流体力学会 年会２０１９, Domestic conference
14 Sep. 2019 - Graded FEM-Meshes for Improved Accuracy and Performance
Mueller Jan; 泉 伊智郎; Matuttis Hans-Georg
Oral presentation, Japanese, 第32回数値流体力学シンポジウム, Domestic conference
13 Dec. 2018 - Damping for the rotation of nonspherical DEM-solids
Krengel Dominik; Matuttis Hans- Georg
Oral presentation, Japanese, 第32回数値流体力学シンポジウム, Domestic conference
13 Dec. 2018 - Alternative Hubbard-Stratonovich Transformations and the Minus Sign Problem
Hans-Georg Matuttis; Katsuaki Kobayashi
Oral presentation, English, 第73 回年次大会（2018 年）
25 Mar. 2018 - Numerically exact formulation for Many-Body Coulomb friction
Oral presentation, English, 日本物理学会 第 73 回年次大会(2018 年)
23 Mar. 2018 - Stress-Strain diagrams for non-convex particles
H.-G. Matuttis; M. Nawa; D. Krengel
Oral presentation, English, Powders & Grains 2017 EPJ Web of Conferences, Domestic conference
04 Jul. 2017 - Unrecognized type of instability in combined Discrete-Element- Finite-Element methods
Fumikazu Morikawa; Hans-Georg Matuttis; Ng Shi Han
Oral presentation, English, THESIS-2016 Two-pHasemodEllingfor Sediment dynamIcS、The 3rd symposium on two-phase modelling for sediment dynamics in geophysical flows, http://c-faculty.chuo-u.ac.jp/~ths2016/, International conference
14 Sep. 2016 - Computation of effective viscosities in Couette-flow with combined particle-fluid simulation
T.L. Cheik; D. Krengel; H.-G. Matuttis
Poster presentation, English, THESIS-2016 Two-pHasemodEllingfor Sediment dynamIcS、The 3rd symposium on two-phase modelling for sediment dynamics in geophysical flows, International conference
13 Sep. 2016 - Size seggregation in fluid-particle mixtures
Fumikazu Morikawa; Hans-Georg Matuttis; Ng Shi Han
Oral presentation, English, 日本物理学会年会, Domestic conference
19 Mar. 2016 - A Discrete Element Method of Non-Convex polygons
MATUTTIS Hans-Georg
Oral presentation, English, 日本流体力学会 年会２０１５, Domestic conference
29 Sep. 2015 - 流体中におけるサイズの異なる粒子の分離の二次元シミュレーション
森川 史和; Shi Han Ng; MATUTTIS Hans-Georg
Oral presentation, Japanese, 日本流体力学会 年会２０１５, Domestic conference
28 Sep. 2015 - Rheology of Fluid-Particle mixtures
TAN Ling Cheik; NG Shi Han; MATUTTIS Hans-Georg
Oral presentation, English, 日本流体力学会 年会２０１５, Domestic conference
28 Sep. 2015 - Coulomb-friction, Differential algebraic systems and the Painleve paradox
Hans-Georg Matuttis; Dominik Krengel; Chen Jian
Poster presentation, English, International Meeting of Friction – from atomic to geophysical scales – Earthquake Research Institute, The University of Tokyo, Domestic conference
14 Sep. 2015 - "Numerically Exact Friction Implementation for Two-dimensional Particle Systems"
Dominik Krengel; Hans-Georg Matuttis
Poster presentation, English, International Meeting of Friction – from atomic to geophysical scales – Earthquake Research Institute, The University of Tokyo, Domestic conference
14 Sep. 2015 - Convergence for the groundstate auxiliary field method
Katsuaki Kobayashi; Hans-Georg Matuttis; Xiaoxing Wang
Poster presentation, English, Dynamics of Strongly Correlated Systems ISSP University of Tokyo, International conference
30 Mar. 2015 - Rheology of Fluid-Particle Mixtures
Ling Cheik Tan; Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, 第７０日本物理学会年次大会
22 Mar. 2015 - Simulation results for spinning tops with a particular distribution of mass and shape
Hans-Georg Matuttis; Hikaru Watanabe
Oral presentation, English, 第７０回物理学会次大会, http://jps2015s.gakkai-web.net/data/html/program11.html, Domestic conference
21 Mar. 2015 - Bulk material strength of polyhedral assemblies
Dominik Krengel; Wei Shen Cheng; Hans-Georg Matuttis
Oral presentation, English, 第７０日本物理学会年次大会, Domestic conference
21 Mar. 2015 - Numerically exact friction implementation for two-dimensional particle systems
Dominik Krengel; Hans-Georg Matuttis
Oral presentation, English, 日本物理学会年会, Domestic conference
19 Mar. 2015 - Thoughts on sampling distributions with “negative probabilities” and the fermionic sign problem
Hans-Georg Matuttis; Xiaoxing Wang; Katsuaki Kobayashi
Poster presentation, English, International Workshop on New Frontier of Numerical Methods for Many-Body Correlations ― Methodologies and Algorithms for Fermion Many-Body Problems, International conference
20 Feb. 2015 - 形状効果による粒状集合の充填密度
Cheng Wei Chen; Krengel Dominik; Matuttis Hans-Georg
Oral presentation, Japanese, 第28回数値流体力学シンポジウム, Domestic conference
09 Dec. 2014 - 地滑りのための微視的なメカニカ ル解析
Tan Ling Cheik; Ng Shi Han; Matuttis Hans-Georg
Oral presentation, Japanese, 第28回数値流体力学シンポジウム, Domestic conference
09 Dec. 2014 - 離散要素法を用いた周囲の粒子による基礎の減衰
森川 史和; Ng Shi Han; Bayat Mehdi; Matuttis Hans-Georg; Andersen Lars Vabbersgaard
Oral presentation, Japanese, 第28回数値流体力学シンポジウム, Domestic conference
09 Dec. 2014 - Shape effects on the density of granular assemblies
Dominik Krengel; Wei Shen Cheng
Oral presentation, English, The 63rd National Congress of Theoretical and Applied Mechanics, Japan, http://news-sv.aij.or.jp/nctam/63/, Domestic conference
26 Sep. 2014 - Synergies from using higher order symplectic decompositions both for ordinary differential equations and quantum Monte Carlo methods
XiaoxingWang; Hans-Georg Matuttis
Public symposium, English, 13TH INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS, Rhodos, International conference
23 Sep. 2014 - Synergies from using higher order symplectic decompositions both for ordinary differential equations and quantum Monte Carlo methods
TH INTERNATIONAL; CONFERENCE OF; NUMERICAL ANALYSIS AND APPLIED MATHEMATICS
Oral presentation, English, 13TH INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATIC, European Society of Computational Methods in Sciences, Engineering and Technology (ESCMCET), Rhodos, Greece, http://www.icnaam.org, International conference
23 Sep. 2014 - Synergies from using higher order symplectic decompositions both for ordinary differential equations and quantum Monte Carlo methods
TH INTERNATIONAL; CONFERENCE OF; NUMERICAL ANALYSIS AND APPLIED MATHEMATICS
Oral presentation, English, 13TH INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATIC, European Society of Computational Methods in Sciences, Engineering and Technology (ESCMCET), Rhodos, Greece, http://www.icnaam.org, International conference
23 Sep. 2014 - 離散要素法を用いた周囲の粒子による基礎の減衰
森川史和; Ng Shihan; Mehdi Bayat; Hans-Georg Matuttis
Oral presentation, Japanese, The 63rd National Congress of Theoretical and Applied Mechanics, Japan, 日本学術会議, http://news-sv.aij.or.jp/nctam/63/#Symposium, Domestic conference
23 Sep. 2014 - The FermionicMinus-SignProblem: Newperceptions from higher-order Suzuki-Trotter decompositionmethods
Hans-Georg Matuttis; Xiaoxing Wang
Poster presentation, English, ISSP International Workshop, “New Horizon of Strongly Correlated Physics” (NHSCP2014), International conference
28 Jun. 2014 - Rheology of Fluid-Particle Mixtures
Hans-Georg Matuttis; Shi Han Ng
Oral presentation, English, 第５５日本物理学会次大会, Domestic conference
Mar. 2014 - From polyhedra to spheres: The e ffect of shape on the density
Dominik Krengel; Hans-Georg Matuttis
Oral presentation, English, 第５５日本物理学会次大会, Domestic conference
Mar. 2014 - Polygonal Particles in Fluids
Shi Han Ng; Hans-Georg Matuttis
Poster presentation, English, Powders and Grains 2013 (Sydney, Australia), International conference
Jul. 2013 - Granular Acoustics of Polyhedral Particles
Wei Shen Cheng; Jian Chen; Hans-Georg Matuttis
Poster presentation, English, Powders and Grains 2013 (Sydney, Australia), International conference
Jul. 2013 - Formation of Granular Heaps in Fluids
Shi Han Ng; Hans-Georg Matuttis
Poster presentation, English, 25th IUPAP International Conference on Statistical Physics (Seoul National University, Seoul, Korea), International conference
Jul. 2013 - Adverse Effects on the Accuracy for “Sampling with Sign” in the Hubbard System
XiaoxingWang; Hans-Georg Matuttis
Poster presentation, English, 25th IUPAP International Conference on Statistical Physics (Seoul National University, Seoul, Korea), International conference
Jul. 2013 - Effect of the surrounding fluid on the compaction of granular materials by tapping: Slow dynamics made slowe
Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, The 4th International Symposium on Slow Dynamics in Complex Systems (Tohoku University)
Dec. 2012 - Incompressible Fluid Simulation with Granular Particles with Adaptive Grid and Adaptive Stepsize
Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, 第61回 理論応用力学講演会, Domestic conference
Mar. 2012 - 多面体を用いて三次元離散要素法の並列化
陳健,Hans-Georg Matuttis
Oral presentation, Japanese, 第61回 理論応用力学講演会, Domestic conference
Mar. 2012 - Combination of Discrete and Finite Elements for the microscopic simulation of particle-loaded flows
Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, International Symposium on Complex Systems 2011 (The University of Tokyo), International conference
Dec. 2011 - Sedimentation of two-dimensional polygonal DEM-particles in an incompressible FEM-fluid
Shi Han Ng; Hans-Georg Matuttis
Poster presentation, English, Nonequilibrium Dynamics in Astrophysics and Material Science (Kyoto University, Yukawa Institue of Theoretical Physics), International conference
Oct. 2011 - Shi Han Ng, Hans-Georg Matuttis
Two-dimensional Microscopic Simulation of Granular Particles in Fluid
Oral presentation, English, 第60回 理論応用力学講演会, Domestic conference
Mar. 2011 - 有限要素法による粘弾性円盤と外壁の接触問題の研究
Jack Widjajakusuma; Hans-Georg Matuttis
Oral presentation, Japanese, 第60回 理論応用力学講演会, Domestic conference
Mar. 2011 - 準二次元の粒状堆積丘に関する研究
Hans-Georg Matuttis
Oral presentation, Japanese, 第60回 理論応用力学講演会, Domestic conference
Mar. 2011 - Simulation of Flow Problems with Free Boundaries in 2D using the Finite Element Method
Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, 第24回数値流体力学シンポジウム, Domestic conference
Dec. 2010 - Adaptive Mesh Generation for two-dimensional Simulation of Polygonal Particles in Fluid
Shi Han Ng; Hans-Georg Matuttis
Oral presentation, English, 第59回 理論応用力学講演会, Domestic conference
Jun. 2010 - Numerical Irreversibility in Energy-Conserving Many Particle Systems
X. Wang; H.-G. Matuttis
Oral presentation, English, 第59回 理論応用力学講演会, Domestic conference
Jun. 2010 - Discrete Element Simulation for Polyhedral Granular Particles
J. Chen; A. Schinner; H.-G. Matuttis
Oral presentation, English, 第59回 理論応用力学講演会, Domestic conference
Jun. 2010 - Numerical irreversibility in many particle systems
X. Wang; H.-G. Matuttis
Oral presentation, English, The 57th Spring Meeting of The Japan Society of Applied Physics and Related Societies, Tokai University, Domestic conference
Mar. 2010 - Discrete element simulation for polyhedral granular particles
Chen Jian; Matuttis Hans-Georg
Oral presentation, English, The 57th Spring Meeting of The Japan Society of Applied Physics and Related Societies, Tokai University, Domestic conference
Mar. 2010 - History Dependence of the Density Distribution on Granular Heaps
Jian Chen; Lisa Watanabe; Hans-Georg Matuttis; Hide Sakaguchi
Poster presentation, English, Powders and Grains 2009, 6th International Conference on Micromechanics of Granular Media (AIP, Golden, Colorado, 2009)., International conference
Jul. 2009 - Simulation of Polygonal Grains in a Finite-Element-Fluid
Yusuke Sakai; Jian Chen; Hans-Georg Matuttis
Poster presentation, English, Powders and Grains 2009, 6th International Conference on Micromechanics of Granular Media (AIP, Golden, Colorado, 2009), International conference
Jul. 2009 - 二次元粉粒体中における応力分布の測定及びシミュレーション
板橋洋平; Hans-Georg Matuttis
Keynote oral presentation, Japanese, 第６１日本物理学会, Domestic conference
Sep. 2006 - 離散要素法による回転運動する楕円扁球の数値シミュレーホン
諏訪光太; Hans-Georg Matuttis
Keynote oral presentation, Japanese, だい６１物理学会, 日本物理学会, Domestic conference
Sep. 2006 - ニュトン流体中の粒子シミュレーション
鈴木宗文; Hans-Georg Matuttis
Keynote oral presentation, Japanese, 第６１日本物理学会, 日本物理学会, Domestic conference
Sep. 2006 - Preliminaries for the Implementation of a simulation of polygonal particles in an incompressible Newtonian Fluid
Takafumi Suzuki; Hans-Georg Matuttis
Keynote oral presentation, Japanese, 国際高等研究所研究プロジェクト 「隙間－自然・人間・社会の現象学」ワークショップ, 財団法人 国際高等研究所 研究支援部, Domestic conference
Aug. 2006 - Strategies for an optimized simulation of granular particles in an incompressible Newtonian Fluid
Hans-Georg Matuttis
Keynote oral presentation, Japanese, 国際高等研究所研究プロジェクト 「隙間－自然・人間・社会の現象学」ワークショップ, 財団法人 国際高等研究所 研究支援部, Domestic conference
Aug. 2006 - 京都大学数理解析研究所講究緑1472
Strategies for; an; o; timize; simulation of granular; particles in a Newtonian; Fluid, Par; Basics
Keynote oral presentation, English, 複雑流体の数理とその応用, Domestic conference
Aug. 2005
Courses
- Phenomenology of Friction
慶應大学 - Phenomenology of Friction
慶應大学 - インターンシップ（海外）（Ｍ, 類III）
The University of Electro-Communications - インターンシップ（海外）（Ｍ, 類III）
電気通信大学 - 研究室見学 (Current Topics in Fundamental Science and Engineering A)
The University of Electro-Communications - 研究室見学 (Current Topics in Fundamental Science and Engineering A)
電気通信大学 - 総合コミュニケーション科学
The University of Electro-Communications - 総合コミュニケーション科学
電気通信大学 - "Special Lecture on Informatics and Engineering A"
The University of Electro-Communications - "Special Lecture on Informatics and Engineering A"
電気通信大学 - Introduction to Computational MEthods in Science and Engineering
The University of Electro-Communications - Introduction to Computational MEthods in Science and Engineering
電気通信大学 - Internship (M, KaigaiM)
The University of Electro-Communications - Internship (M, KaigaiM)
電気通信大学 - Nihon Gijutsu Kagaku B
The University of Electro-Communications - Nihon Gijutsu Kagaku B
電気通信大学 - Graduate Technical English
The University of Electro-Communications - Graduate Technical English
電気通信大学 - Butsurigaku Enshuu 1I
The University of Electro-Communications - Butsurigaku Enshuu 1I
電気通信大学 - Butsurigaku Enshuu 1
The University of Electro-Communications - Butsurigaku Enshuu 1
電気通信大学 - Special Lecture on Information and Engineering A (Curretn Topics in Fundamental Science and Engineering A)
The University of Electro-Communications - Special Lecture on Information and Engineering A (Curretn Topics in Fundamental Science and Engineering A)
The University of Electro-Communications - インターンシップ（Ｍ, 類III）、インターンシップ（海外）（Ｍ, 類III））
The University of Electro-Communications - インターンシップ（Ｍ, 類III）、インターンシップ（海外）（Ｍ, 類III））
電気通信大学 - Introduction to computational methods in science and engineering
The University of Electro-Communications - Introduction to computational methods in science and engineering
The University of Electro-Communications - インターンシップ（Ｍ）、インターンシップ（海外）（Ｍ）
The University of Electro-Communications - インターンシップ（Ｍ）、インターンシップ（海外）（Ｍ）
電気通信大学 - 日本御術科学B
The University of Electro-Communications - 大学院技術英語
The University of Electro-Communications - Introduction to computational methods in science and engineering
The University of Electro-Communications - 基礎物理学演習 I
The University of Electro-Communications - PBL
The University of Electro-Communications - PBL
電気通信大学 - 学部インターンシップ担当
The University of Electro-Communications - 学部インターンシップ担当
電気通信大学 - インターンシップ担当
The University of Electro-Communications - インターンシップ担当
電気通信大学 - 力学系現象特論
The University of Electro-Communications - 基礎物理学演習 II
The University of Electro-Communications - 日本御術科学B
The University of Electro-Communications - 日本御術科学B
電気通信大学 - 大学院技術英語
The University of Electro-Communications - 大学院技術英語
電気通信大学 - 海外インターンシップ
The University of Electro-Communications - 海外インターンシップ
電気通信大学 - インターンシップ
The University of Electro-Communications - インターンシップ
電気通信大学 - 力学系現象特論
The University of Electro-Communications - 力学系現象特論
電気通信大学 - 基礎物理学演習 II
The University of Electro-Communications - 基礎物理学演習 II
電気通信大学 - 基礎物理学演習 I
The University of Electro-Communications - 基礎物理学演習 I
電気通信大学