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TZID:Europe/Paris
LAST-MODIFIED:20040526T134920Z
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X-WR-CALNAME:Events of KNM MFF UK - Seminar of Numerical Mathematics
X-WR-CALDESC:Calendar of events of KNM MFF UK - Seminar of Numerical Mathematics
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260430T140000
DTEND;TZID=Europe/Paris:20260430T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1173@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Controlled time integration with discrete exterior calculus: applications in electro-magnetism, acoustics and more
DESCRIPTION:Tytti Saksa\n room:K3\n We discuss controlled time integration for propagation of electro-magnetic, acoustic etc. waves. In the controlled time integration, we do not solve the time-dependent problem directly but instead we accelerate the convergence of solution by minimizing the difference between an initial solution and the corresponding solution after one time period. The controlled time integration has shown its potential for complex geometries, e.g. scattering problems with non- convex scatterers. Such wave problems may be discretized by many different methods. For each step in the controlled time integration, we solve the problem once forward in time and once backward in time over one time period. Discrete exterior calculus provides us with a diagonal mass matrix for fast time integration. In discrete exterior calculus, we need to pay attention to the quality of the mesh to achieve a desired solution accuracy. We present numerical examples to demonstrate the computational performance of the methods.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1173
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260423T140000
DTEND;TZID=Europe/Paris:20260423T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1175@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The Parallel Sparse Computation Toolkit (PSCToolkit): bringing linear algebra to the extreme scale
DESCRIPTION:Fabio Durastante\n room:K1\n The increasing demand for high-fidelity simulations in science and engineering is driving computational methods toward extreme-scale architectures, where efficiency, scalability, and robustness of linear algebra operations become critical. This talk presents the Parallel Sparse Computation Toolkit (PSCToolkit), a suite of libraries designed to address these challenges by enabling efficient sparse linear algebra computations on modern high-performance computing systems. We will first outline the core design and implementation strategies behind PSCToolkit, including its data structures, parallelization model, and communication patterns tailored for distributed-memory environments. Emphasis will be placed on how the toolkit achieves scalability while maintaining flexibility and ease of use. The talk will then showcase representative use cases, demonstrating how PSCToolkit can be employed to solve large-scale problems arising in scientific computing. These examples highlight both performance characteristics and practical integration into existing workflows. Finally, we will discuss the integration of PSCToolkit within the deal.II finite element library, illustrating how advanced sparse linear algebra capabilities can be seamlessly incorporated into established numerical frameworks. This integration enables users to leverage extreme-scale performance in real-world finite element applications. Overall, the presentation aims to provide insight into the role of modern sparse computation tools in pushing the boundaries of large-scale numerical simulation. The material presented in this talk is the result of collaborative work with Pasqua D'Ambra (IAC-CNR), Salvatore Filippone, and Marco Feder (University of Rome "Tor Vergata").
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1175
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260416T140000
DTEND;TZID=Europe/Paris:20260416T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1174@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Riesz basis of ReLU neural networks and its use in function recovery
DESCRIPTION:Jan Vybíral\n room:K1\n We present a survey of our recent study of the trigonometric-like system of piecewise linear functions introduced by Daubechies, DeVore, Foucart, Hanin, and Petrova. In our previous work we gave an alternative proof that this system forms a Riesz basis of $L_2([0,1])$. More importantly, we generalized this system to higher dimensions $d>1$ by a construction, which avoids using (tensor) products. As a consequence, the functions from the new Riesz basis of $L_2([0,1]^d)$ can be easily represented by neural networks. As a byproduct, we also prove that the Riesz constants of this system are independent of $d$, making it an attractive building block regarding multivariate analysis of neural networks. In our recent work we used this Riesz basis and investigated how well can a multivariate function of a limited smoothness be approximated by deep neural networks of given length and width. Such questions were recently intensively studied from many points of view. Our approach differs from most of these works by employing a basis, which lies on the interface between Fourier analysis and artificial neural networks. Finally, we report on a recent work, which studies the behavior of the same Riesz basis in Lebesgue spaces $L_p([0,1]^d)$ for $1\le p\le\infty$.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1174
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260409T140000
DTEND;TZID=Europe/Paris:20260409T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1172@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Od vidění k interpretaci: obrazová analýza v různých oborech
DESCRIPTION:Barbara Zitová\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1172
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260402T140000
DTEND;TZID=Europe/Paris:20260402T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1171@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Challenges for numerical simulation of spin dynamics in magnetic resonance
DESCRIPTION:Zdeněk Tošner\n room:K1\n Nuclear magnetic resonance spectroscopy (NMR) is a versatile technique capable to study molecular structure and dynamics at atomic resolution. The underlying quantum mechanics principles and weak interactions allow for detailed description of how nuclear spins respond to external radiofrequency irradiaton. By modulating this irradiation, we can highlight or suppress individual interactions between spins and read out the relevant information. NMR is ideal for application of optimal control theory to design sophisticated experiments with much improved sensitivity. Numerical simulations solving the time dependent Liouville-von Neumann equation are faced with several challenges including exponential scaling of matrix sizes, non-commuting contributions, very fast time variations, and the necessity to follow the dynamics over relatively long evolution times. These numerical problems will be presented within the application to ultra-fast magic angle spinning solid-state NMR of proteins, highlighting the potential of this technique for advanced structural biology studies.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1171
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260326T140000
DTEND;TZID=Europe/Paris:20260326T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1170@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite element form-valued forms
DESCRIPTION:Kaibo Hu\n room:K1\n Some of the most successful vector-valued finite elements in computational electromagnetics and fluid mechanics, such as the Nédélec and Raviart-Thomas elements, are recognized as special cases of Whitney's discrete differential forms. Recent efforts aim to go beyond differential forms and establish canonical discretizations for more general tensors. An important class is that of form-valued forms, or double forms, which includes the metric tensor (symmetric (1,1)-forms) and the curvature tensor (symmetric (2,2)-forms). Like the differential structure of forms is encoded in the de Rham complex, that of double forms is encoded in the Bernstein–Gelfand–Gelfand (BGG) sequences and their cohomologies. Important examples include the Calabi complex in geometry and the Kröner complex in continuum mechanics.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1170
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260319T140000
DTEND;TZID=Europe/Paris:20260319T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1169@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Bregman divergences and error control via convex duality
DESCRIPTION:Alexei Gazca\n room:K1\n Convex duality relations are a useful tool for deriving error estimates for challenging nonlinear and non-smooth variational problems, including total variation minimisation, the p-Laplacian, the obstacle problem, elastoplastic torsion, among others. Applied at the continuous level they can deliver nonlinear analogues of the Prager-Synge a posteriori error identity, while at the discrete level they allow the derivation of minimal regularity a priori estimates. By leveraging elementary properties of Bregman divergences, we obtain three results on the error control via convex duality for a general class of problems: first, we prove the local efficiency of the duality gap error estimator, secondly, we derive a guaranteed a posteriori bound for non-conforming fields, and finally, we prove a minimal-regularity quasioptimal estimate for a Crouzeix--Raviart discretisation of the (phi)-Laplace problem. We will also discuss extensions to the vectorial setting, focusing on the prototypical incompressible Stokes and linear elasticity systems. This is joint work with Alex Kaltenbach (TU Berlin).
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1169
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260312T140000
DTEND;TZID=Europe/Paris:20260312T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1168@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite precision block Lanczos computations
DESCRIPTION:Dorota Šimonová\n room:K3\n The block Lanczos algorithm, a variant of the Lanczos algorithm operating with block vectors, is used in many applications, yet its behavior in finite precision arithmetic is not well understood. For the single-vector Lanczos algorithm, Greenbaum, building on the numerical analysis of Paige, presented a backward-like stable mathematical model of Lanczos computations. The basic idea is to construct a larger matrix from the one generated by finite precision computations whose eigenvalues lie in small intervals around those of the original matrix. An analogous construction can be defined for the block Lanczos algorithm; however, the absence of a block analogue of Paige's analysis complicates proving properties similar to those known in the single-vector case. Nevertheless, numerical experiments suggest that analogous properties may hold in practice.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1168
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260305T140000
DTEND;TZID=Europe/Paris:20260305T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1167@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical simulation of hypersonic flows
DESCRIPTION:Jiří Holman\n room:K3\n The lecture deals with the mathematical modeling and numerical solution of hypersonic flows, which are characterized by a Mach number greater than five. The particular mathematical model used consists of averaged Navier-Stokes equations completed with an explicit algebraic Reynolds stress model (EARSM) and an additional algebraic model of transition. The numerical solution is obtained using the finite volume method, which is based on a rotated-hybrid Riemann solver and an explicit, strong stability preserving (SSP) Runge-Kutta method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1167
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260226T140000
DTEND;TZID=Europe/Paris:20260226T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1166@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Mixed-precision Computing: High Accuracy With Low Precision
DESCRIPTION:Erin Claire Carson\n room:K3\n Mixed-precision algorithms have launched an era in which efficiency and accuracy are no longer mutually exclusive. Rather than rely entirely on high-precision formats like double (64-bit) precision, mixed-precision algorithms apply lower precisions such as single (32-bit) or half (16-bit) precision whenever possible, reserving higher precision only for critical steps. Doing so can drastically reduce memory requirements, improve performance, and lessen energy consumption on modern computer hardware without sacrificing accuracy or stability. In this talk, we discuss the challenges of using low/mixed precision, and present five cases, common in scientific applications, where using mixed precision makes sense.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1166
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260219T140000
DTEND;TZID=Europe/Paris:20260219T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1165@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled
DESCRIPTION:\n room:K1\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1165
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260212T140000
DTEND;TZID=Europe/Paris:20260212T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1164@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Non-Markovian models of collective motion
DESCRIPTION:Jan Haškovec\n room:K2\n I will give an overview of recent results for models of collective behavior governed by functional differential equations with non-Markovian structure. The talk will focus on models of interacting agents with applications in biology (flocking, swarming), social sciences (opinion formation) and engineering (swarm robotics), where latency (delay) plays a significant role. I will characterize two main sources of delay - inter-agent communications ("transmission delay") and information processing ("reaction delay") - and discuss their impacts on the group dynamics. I will give an overview of analytical methods for studying the asymptotic behavior of the models in question and their mean-field limits. In particular, I will show that the transmission vs. reaction delay leads to fundamentally different mathematical structures and requires appropriate choice of analytical tools. Finally, motivated by situations where finite speed of information propagation is significant, I will introduce an interesting class of problems where the delay depends nontrivially and nonlinearly on the state of the system, and discuss the available analytical results and open problems here.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1164
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260108T140000
DTEND;TZID=Europe/Paris:20260108T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1163@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Turbulence modeling in CFD
DESCRIPTION:Jiří Fürst\n room:K3\n The lecture focuses on basic concepts of turbulence modeling for engineering applications. We will introduce turbulent scales and energy spectra at the beginning of the lecture and we will discuss its impact to different modeling strategies. Next, the Reynolds averaged Navier-Stokes (RANS) approach will be described together with some well established turbulence models. Treatment of boundary layers using wall resolved or wall function approach will be discussed. In the following part basics of large eddy simulation (LES) will be given. The attention will be focused mainly to required resolution for LES method. Some advanced topics will be mentioned at the final part of the lecture.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1163
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251218T140000
DTEND;TZID=Europe/Paris:20251218T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1162@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1162
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251211T140000
DTEND;TZID=Europe/Paris:20251211T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1160@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The latent variable proximal point method for variational problems with inequality constraints
DESCRIPTION:Patrick Farrell\n room:K3\n The latent variable proximal point (LVPP) algorithm is a new framework for solving infinite-dimensional variational problems with inequality constraints. The algorithm is a saddle point reformulation of the Bregman proximal point algorithm. At the continuous level, the two formulations are equivalent, but the saddle point formulation is more amenable to discretisation. LVPP yields numerical methods with observed mesh-independence for obstacle problems, contact, fracture, plasticity, and others besides. In many cases this mesh independence is achieved for the first time. The framework also extends to more complex constraints, providing means to enforce convexity in the Monge-Ampère equation and gracefully handling quasi-variational inequalities, where the underlying constraint depends implicitly on the unknown solution. In this talk we describe the LVPP algorithm in a general form and apply it to a number of problems from across mathematics.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1160
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251204T140000
DTEND;TZID=Europe/Paris:20251204T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1161@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Degenerate finite elements: turning a bug into a feature
DESCRIPTION:Václav Kučera\n room:K3\n Degenerate elements, i.e. flat or (nearly) zero measure elements, are a severe obstacle in classical finite element methods requiring special mesh adjustments, especially in 3D. In our recent paper, the Tempered Finite Element Method (TFEM) was introduced, which bypasses these problems. TFEM even allows to take advantage of bad elements, effectively turning a bug into a feature - degenerate elements can now be used to easily implement mortaring, penalization, or even discontinuous Galerkin methods by trivially modifying vanilla finite element codes. We give an overview of these approaches and the theory and practice behind them.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1161
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251127T140000
DTEND;TZID=Europe/Paris:20251127T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1159@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical optimization in nonlinear elasticity
DESCRIPTION:Marc Fehling\n room:K3\n Large deformations in elastic solids require nonlinear theory. Associated constitutive relations are often highly complex, posing significant challenges for numerical simulation. We propose an approach that formulates the large deformation problem as a numerical optimization over continuous piecewise polynomials. Given boundary displacements and an energy functional derived from the constitutive law, we compute the displacement field that minimizes the total energy of the body. Our prototype implementation leverages both open-source libraries ROL for numerical optimization and deal.II for finite element discretization. We present preliminary results for a buckling problem to demonstrate the method's potential.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1159
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251120T140000
DTEND;TZID=Europe/Paris:20251120T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1158@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On a shrink-and-expand technique for symmetric block eigensolvers
DESCRIPTION:Yuxin Ma\n room:K3\n In symmetric block eigenvalue algorithms, such as the subspace iteration algorithm and the locally optimal block preconditioned conjugate gradient (LOBPCG) algorithm, a large block size is often employed to achieve robustness and rapid convergence. However, using a large block size also increases the computational cost. Traditionally, the block size is typically reduced after convergence of some eigenpairs, known as deflation. In this work, we propose a non-deflation-based, more aggressive technique, where the block size is adjusted dynamically during the algorithm. This technique can be applied to a wide range of block eigensolvers, reducing computational cost without compromising convergence speed. We present three adaptive strategies for adjusting the block size, and apply them to four well-known eigensolvers as examples. Detailed theoretical analysis and numerical experiments are provided to illustrate the efficiency of the proposed technique. In practice, an overall acceleration of 20% to 30% is observed.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1158
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251113T140000
DTEND;TZID=Europe/Paris:20251113T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1157@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:New postdoc presentations
DESCRIPTION:Ritesh Khan, Santolo Leveque\n room:K3\n Accelerating Dense Matrix Computations Using Hierarchical Matrices (R. Khan); An Augmented Lagrangian Preconditioner for a Runge--Kutta Discretization of Instationary Incompressible Viscous Fluid Flow Problems (S. Leveque)
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1157
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251106T140000
DTEND;TZID=Europe/Paris:20251106T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1156@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A New Tapered Precision Machine Number Format
DESCRIPTION:Laslo Hunhold\n room:K3\n IEEE 754 floating-point arithmetic has dominated computing for decades, but the necessary shift towards low-precision computing has exposed its limitations, both in machine learning and, with mixed-precision methods, in computational mathematics. New number formats such as OFP8, bfloat16, and posits have been proposed, but they are primarily tailored for AI workloads and small dynamic ranges, not general-purpose computation. In mixed-precision contexts, reducing precision typically entails a significant reduction in representable dynamic range, necessitating specialised approaches. This talk presents takum, a new number format that maintains a constant, general-purpose dynamic range even at extremely low precisions, so reducing precision affects only accuracy. I will present results showing that takums outperform IEEE 754 floats, improve over posits for general-purpose use, and offer new arithmetic properties and promising avenues for hardware implementation.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1156
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251030T140000
DTEND;TZID=Europe/Paris:20251030T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1155@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Scalable domain decomposition solver for three-grid immersed finite element method
DESCRIPTION:Jakub Šístek\n room:K3\n Immersed boundary finite element method (FEM) presents an attractive approach to simulations avoiding the generation of large body-fitted meshes. This can be tedious and challenging for complex geometries as well as for very fine adaptive meshes distributed over a parallel supercomputer. However, the price to pay are more complicated formulations for the weak enforcement of Dirichlet boundary conditions, poor conditioning of stiffness matrices, and nonstandard numerical integration at the boundary. [1] E. Febrianto, J. Šístek, P. Kůs, M. Kecman, and F. Cirak. A three-grid high-order immersed finite element method for the analysis of CAD models. Computer-Aided Design, 173:103730, 2024. We develop multilevel balancing domain decomposition based on constraints (BDDC) method tailored to the solution of the linear systems arising in the context of immersed boundary FEM with parallel adaptive grid refinement using Z-curves (based on the p4est library). One crucial challenge is presented by fragmenting of subdomains, which has two sources: i) the partitioning strategy based on space-filling curves, and ii) extraction of the elements contributing to the stiffness matrix. Numerical results for large-scale Poisson and linear elasticity problems on complex geometries from engineering will be presented. The presentation is largely based on our recent paper [1]. This is joint work with Monika Balázsová, Fehmi Cirak, Eky Febrianto, Matija Kecman, Pavel Kůs, and Josef Musil.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1155
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251023T140000
DTEND;TZID=Europe/Paris:20251023T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1154@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Adaptive domain decomposition techniques for the numerical solution of time-dependent problems
DESCRIPTION:Vít Dolejší\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1154
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251016T140000
DTEND;TZID=Europe/Paris:20251016T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1153@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Low-rank and randomized enhancements of the ★-approach for solving differential equations
DESCRIPTION:Alberto Bucci\n room:K3\n In this talk, I will present new randomized and low-rank techniques developed within the framework of the ★-approach, aimed at efficiently addressing the numerical solution of differential equations. The key idea is to exploit the inherent low-rank structure that often emerges in the discretization of such problems and to combine it with randomized methods to improve computational efficiency and scalability. I will begin by introducing the basic formulation of the underlying problem and the fundamentals of low-rank approximation in modern numerical linear algebra. Then, I will illustrate how these tools can be integrated into the ★-approach and discuss some of the results obtained in my recent research, including applications to nuclear magnetic resonance problems in chemistry.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1153
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251009T140000
DTEND;TZID=Europe/Paris:20251009T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1151@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Evolution of Environmental Modeling in the Era of Exascale Computing
DESCRIPTION:Simone Marras\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1151
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20251002T140000
DTEND;TZID=Europe/Paris:20251002T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1152@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled - Winter semester kick-off
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1152
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250522T140000
DTEND;TZID=Europe/Paris:20250522T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1150@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special master students seminar
DESCRIPTION:Ondřej Brichta, Martin Novák, Kateřina Pokorná\n room:K1\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1150
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250515T140000
DTEND;TZID=Europe/Paris:20250515T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1149@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Rational functions in quantum computing
DESCRIPTION:Niel Van Buggenhout\n room:K1\n In classical computing, rational functions form an essential tool for developing effective algorithms for solving interior eigenvalue problems and approximating matrix functions. In quantum computing, the use of rational functions is underexplored. In this talk we explore a new technique for working with rational functions on a quantum computer. This technique is thus a proposal for the main building block of quantum rational algorithms and is based on real-time evolutions. We provide a detailed computational cost analysis that is essential for further development of quantum rational algorithms.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1149
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250424T140000
DTEND;TZID=Europe/Paris:20250424T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1142@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Analysis of the block CG method
DESCRIPTION:Petr Tichý\n room:K1\n The Block Conjugate Gradient (BCG) algorithm was introduced by D.P. O'Leary in 1980 for solving linear systems with multiple right-hand sides. In general, block methods apply the matrix to a block of vectors instead of a single vector at each iteration. This operation is used to construct a common subspace for all right-hand sides, resulting in a richer search subspace. From a computational perspective, block methods have the potential to take advantage of the capabilities of modern computers. In this talk we recall the development of BCG algorithms. We clarify the close relationship between BCG and the block Lanczos algorithm and show how to obtain the block Jacobi matrices in BCG. This opens the door for further development, e.g., for error estimation based on (modified) block Gauss quadrature rules. Driven by the need to obtain a practical variant of the BCG algorithm that is well suited for computations in finite precision arithmetic, we also discuss some important variants of BCG due to Dubrulle. These variants avoid the difficulties with a possible rank deficiency within the block vectors. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1142
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250417T140000
DTEND;TZID=Europe/Paris:20250417T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1148@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Some Numerical Aspects of Differential Models with Fractional Derivatives
DESCRIPTION:Mariarosa Mazza\n room:K1\n Fractional derivatives, a widely recognized mathematical tool, have gained considerable attention in recent decades owing to their non-local behavior, particularly suitable for capturing anomalous diffusivity. They find application in various real-world scenarios that range from the interaction between particles and fields within plasma to the dynamics of networks in human environments. While the presence of a fractional derivative in a differential model can result in a better physical description, it also poses significant challenges in numerical treatment. Specialized strategies, including discretization methods and numerical solvers, are required to address such challenges effectively. This presentation aims to offer insight into the topic, with a specific emphasis on the numerical linear algebra obstacles it entails.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1148
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250410T140000
DTEND;TZID=Europe/Paris:20250410T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1147@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Deflated PCG in problems of incompressible flows
DESCRIPTION:Jan Papež\n room:K1\n When solving incompressible flow problems using the Balancing Domain Decomposition by Constraints (BDDC) method, one encounters a sequence of Poisson problems for the pressure. These problems share the same system matrix but have varying right-hand sides corresponding to different time steps. Each time step is typically solved using the preconditioned conjugate gradient (PCG) method, with BDDC serving as the preconditioner. It can be shown that the eigenvalues of the preconditioned system are greater or equal to one and typically remain bounded by $O(1)$. In this talk, we discuss the choice of stopping criteria for PCG and demonstrate that deflation can be effectively applied to this sequence of problems. In contrast to its usual application, we construct the deflation space to mitigate the influence of large, outlying eigenvalues. Numerical experiments confirm that this approach yields a significant reduction (up to 25%) in both the number of PCG iterations and the overall computation time. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1147
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250403T140000
DTEND;TZID=Europe/Paris:20250403T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1146@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Moment sum-of-square hierarchies for arrow-type polynomial matrix inequalities
DESCRIPTION:Marouan Handa\n room:K1\n The Arrow Decomposition (AD) technique has demonstrated superior scalability compared to classical chordal decomposition for Linear Matrix Inequalities when the matrix satisfies suitable assumptions. In this talk, we present an extension of the AD method to handle polynomial optimization problems involving Polynomial Matrix Inequalities as constraints, with the solution framework relying on the Lasserre’s moment-sum of squares hierarchies. We finally present the application of AD to topology optimization of frame structures.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1146
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250327T140000
DTEND;TZID=Europe/Paris:20250327T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1144@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The multi-variable spectral geometric mean
DESCRIPTION:Vatsalkumar N. Mer\n room:K1\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1144
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250320T140000
DTEND;TZID=Europe/Paris:20250320T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1145@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Streaming and randomized techniques for low-rank approximation of matrices and tensors with applications
DESCRIPTION:Alberto Bucci\n room:K1\n  In this talk, we will review popular techniques for the low-rank approximation of matrices and tensors and explore their extension to a streamable setting, where data can only be accessed once, requiring efficient, single-pass algorithms. We will provide theoretical insights and performance analysis. We will then focus on a recent research direction where these streamable techniques play a crucial role: solving linear systems and least squares problems in various low-rank formats. In particular, we will discuss low-rank sketched GMRES and sketched LSQR, highlighting their advantages and challenges and their connection with the recent developed star process.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1145
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250313T140000
DTEND;TZID=Europe/Paris:20250313T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1143@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Biomembrane Remodeling: From Local Interactions to Continuum Models
DESCRIPTION:Christoph Allolio\n room:K1\n Lipid membranes compartmentalize the cell and isolate it from its surroundings. Their function as a barrier can be part of a defensive, transport or regulatory mechanism. Modification of the membrane geometry is called biomembrane remodeling, and is essential to membrane function. We developed a set of tools to extract the effect of adsorption and local composition from particle based simulation into continuum parameters. In addition, we recently published a numerical solver for arbitrary membrane geometries and compositions. I will describe our approach in some detail, show first applications and explain current challenges with a view on potential collaborations.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1143
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250306T140000
DTEND;TZID=Europe/Paris:20250306T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1140@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Geometry processing with discrete exterior calculus
DESCRIPTION:Lenka Ptáčková\n room:K1\n We present a novel discretization of exterior calculus on surface meshes formed by general polygons, possibly non-convex and non-planar. Within this framework we define new discrete versions of several differential operators, e.g., Laplace--de Rham operator or Lie derivative, examine their numerical convergence, and illustrate their application for tasks such as Helmholtz--Hodge decomposition of vector fields, mean curvature flow of surface meshes, or Lie advection of vector fields.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1140
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250227T140000
DTEND;TZID=Europe/Paris:20250227T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1141@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Low precision incomplete Cholesky factorization preconditioning
DESCRIPTION:Miroslav Tůma\n room:K1\n The talk will discuss a recent interest in computing approximate matrix factorizations in low precision and employing them as preconditioners within a mixed precision iterative refinement-based approach for solving linear systems of equations. For large sparse systems, incomplete factorization preconditioners can be an attractive option as they are general-purpose and have been successfully applied to solve systems arising from diverse application areas. Our focus is on computing such preconditioners for solving large sparse systems of linear algebraic equations. For simplicity, we are interested in preconditioning systems Ax=b with A symmetric positive definite. Numerical results obtained with the NAG Fortran compiler that correctly simulates the half precision arithmetic illustrate the potential effectiveness of the half precision preconditioner in solving highly ill-conditioned systems to double precision accuracy.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1141
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250220T140000
DTEND;TZID=Europe/Paris:20250220T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1139@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Matrix perturbation analysis of methods for extracting singular values given approximate subspaces
DESCRIPTION:Lorenzo Lazzarino\n room:K1\n Given (orthonormal) approximations to the left and right subspaces spanned by the leading singular vectors of a matrix A, we discuss methods to approximate the leading singular values of A and study their accuracy. In particular, we focus our analysis on the generalized Nyström approximation, as surprisingly, it is able to obtain significantly better accuracy than classical methods, namely Rayleigh-Ritz and (one-sided) projected SVD. A key idea of the analysis is to view the methods as finding the exact singular values of a perturbation of A. In this context, we derive a matrix perturbation result that exploits the structure of such $2\times 2$ block matrix perturbation. We then obtain bounds on the accuracy of the extracted singular values. This leads to sharp bounds that predict well the approximation error trends and explain the difference in the behavior of these methods. Our theoretical results translate into practical insights on how best to approximate singular values given approximate subspaces. Numerical experiments highlight how the derived bounds exhibit tighter estimates than classical bounds, effectively capturing the trends observed empirically. For instance, the bounds reflect a more gradual change in error across the leading singular values. [1] Matrix perturbation analysis of methods for extracting singular values from approximate singular subspaces, L. Lazzarino, H. Al Daas, Y. Nakatsukasa, 2024, arXiv:2409.09187
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1139
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250130T143000
DTEND;TZID=Europe/Paris:20250130T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1138@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Spectral properties of certain nonsymmetric saddle point matrices
DESCRIPTION:Jörg Liesen\n room:K433KNM\n We consider certain (real) nonsymmetric matrices in saddle point form, study their general Jordan normal forms, and prove new conditions so that these matrices are diagonalizable with a real spectrum. For matrices satisfying our conditions we show how to construct an inner product in which these matrices are selfadjoint. Our approach generalizes previously published results in this area, which require stronger assumptions on the given saddle point matrices and hence are less widely applicable.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1138
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250109T140000
DTEND;TZID=Europe/Paris:20250109T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1137@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Star dance: from wide pairs to collisions
DESCRIPTION:Ondřej Pejcha\n room:K3\n Our Sun is a single star, which is somewhat of an exception in the Universe as most stars are found in binary and multiple systems. For a wide range of initial conditions at stellar birth, the two stars in a binary will interact by exchanging mass, exploding, or merging to a single object. Computer simulations of binary systems are indispensable in revealing the fundamental physical processes governing the binary's structure and evolution, yet they are complicated by a lack of any useful symmetry. In this talk I will review results of radiation/magneto-hydrodynamical simulations of a certain evolutionary phase studied in my ERC StG, and describe plans for a new set of simulations with discontinuous Galerkin method to be done with the support of ERC CoG.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1137
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241219T140000
DTEND;TZID=Europe/Paris:20241219T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1136@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Algebraic stabilizations of convection-diffusion-reaction equations
DESCRIPTION:Petr Knobloch\n room:K3\n Convection-diffusion-reaction equations appear in many mathematical models of physical, technical or biological processes. Often, the diffusion is very small in comparison with the convection or reaction, which causes that the solutions comprise layers. It is well known that standard numerical methods then provide approximate solutions polluted by spurious oscillations unless the underlying mesh resolves the layers. During the last five decades, many various stabilized methods for convection-diffusion-reaction equations have been developed and it turns out that, due to the multiscale character of the problem, accurate approximate solutions can be obtained only if nonlinear approaches are used. However, in general, some spurious oscillations are often still present, which may be not acceptable in many applications. The only possibility to avoid violations of global bounds it to use discretizations satisfying the discrete maximum principle (DMP). An important class of such methods are algebraically stabilized schemes. These methods have been intensively developed in recent years and we will formulate an abstract framework that enables the analysis of algebraically stabilized discretizations for steady-state problems in a unified way. We will present general results on local and global DMPs, existence of solutions, and error estimation. Then, various examples of algebraic stabilizations fitting into the abstract framework will be given and applied to discretizations of steady-state convection-diffusion-reaction equations. The properties of these particular algebraic stabilizations will be discussed both theoretically and by means of numerical examples.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1136
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241212T140000
DTEND;TZID=Europe/Paris:20241212T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1135@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Divergence-preserving methods for incompressible flow
DESCRIPTION:Jan Blechta\n room:K3\n In this review talk the structure-preserving property of discretizations for incompressible flow that is called pressure robustness will be covered. It is arguably the most important development of the last decade in the field: "[P]ressure-robust space discretisations outperform non-pressure-robust space discretisations for incompressible Navier–Stokes flows, especially at high Reynolds numbers." [Gauger, Linke, Schroeder 2019] "[P]ressure-robust schemes outperform non-pressure-robust schemes for entire classes of transient incompressible flows at high Reynolds numbers." [Lederer, Merdon, Schöberl 2019] Classical discretizations of incompressible flow, such as the Hood–Taylor mixed element or the MINI element, enforce mass conservation in the sense of L2 orthogonality to the pressure space. It turns out that, in the simplest case of the stationary Stokes system, this leads to the velocity discretization error being polluted by the pressure error, which gives the name to the phenomenon of pressure nonrobustness. This can also be viewed as the incompatibility of the discretization with the Helmholtz decomposition. On practical level this leads to various kinds of instabilities. On the other hand the schemes which enforce the mass conservation pointwise are free of these problems. The difficult part is to establish inf-sup stability. In this talk I will cover classical results concerning the stability (or the lack of) for the divergence-free Scott–Vogelius pair, new results giving its stability on special (but useful) classes of meshes, overview its connection to the de Rham complex and the finite element exterior calculus, and mention other types of divergence-preserving discretizations. I will also give few computational examples showing how pressure nonrobustness results in various kind of instabilities. Last but not least, it will be shown how certain simple divergence-preserving schemes can be implemented with ease, thus allowing computational practitioners to ditch the everlasting, pressure non-robust, Hood–Taylor method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1135
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241205T140000
DTEND;TZID=Europe/Paris:20241205T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1134@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Lower bounds on the eigenvalues by Crouzeix-Raviart finite elements
DESCRIPTION:Tomáš Vejchodský\n room:K3\n In this talk, we will explain how to compute lower bounds on eigenvalues of the Laplace eigenvalue problem by the Crouzeix-Raviart finite element method. Computing estimates on eigenvalues of elliptic operators from below is a challenging task that requires elaborated methods and often some a priori knowledge about the exact spectrum. However, in the case of the Laplace operator, the elliptic projector coincides with the Crouzeix-Raviart interpolation operator, and we can explicitly obtain the corresponding interpolation constant. These special properties enable us to compute accurate lower bounds on eigenvalues easily.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1134
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241128T140000
DTEND;TZID=Europe/Paris:20241128T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1133@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A posteriori estimates and flux reconstructions
DESCRIPTION:Miloslav Vlasák\n room:K3\n The usual a posteriori error estimates for elliptic problems based on the flux reconstructions principle will be shown. The most common flux reconstruction uses a complicated procedure based on the mixed finite element method. We will show that a much simpler direct reconstruction can have similar properties and can be applied with satisfactory results.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1133
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241121T140000
DTEND;TZID=Europe/Paris:20241121T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1128@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Three hot topics in Domain Decomposition research
DESCRIPTION:Martin Gander\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1128
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241114T140000
DTEND;TZID=Europe/Paris:20241114T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1132@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Tempered Finite Elements: A novel method for computing on degenerate meshes
DESCRIPTION:Václav Kučera\n room:K3\n Classical finite elements fail to converge when the triangulation of the computational domain contains too many degenerating elements organized in large structures. Such triangulations are however important from the practical point of view, In this talk we present a simple novel modification of the finite element method which allows to compute on meshes containing arbitrarily degenerate elements, even ones with zero or negative measure. We present the theory as well as practice of this new technique.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1132
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241107T140000
DTEND;TZID=Europe/Paris:20241107T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1130@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Preconditioning the Stage Equations of Implicit Runge Kutta Methods
DESCRIPTION:Michal Outrata\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1130
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241031T140000
DTEND;TZID=Europe/Paris:20241031T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1131@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Control of Stochastic Second-Order Systems: A Case Study of the Torsional Harmonic Oscillator
DESCRIPTION:Cristina Perez Diukina\n room:K3\n In this study, we explore the data of two harmonic oscillators that present inherent uncertainties in their behavior. Our focus is on understanding whether the dynamics of the Torsional Harmonic Oscillator and its control might benefit from being approached probabilistically rather than through conventional deterministic methods. To investigate this, we introduce randomness into the system through the system's parameters, converting the governing equations into Random Differential Equations. The data collected from the oscillators, subjected to perturbations, help us begin to calibrate these random models. By examining this evolving model alongside the data, we aim to refine our understanding of the system's dynamic behavior and cautiously propose a control scheme. This approach potentially offers more constrained but adjustable solutions than traditional deterministic models.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1131
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241024T140000
DTEND;TZID=Europe/Paris:20241024T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1129@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special Bachelor student seminar
DESCRIPTION:Milan Đurović, Josef Gajdůšek, Jiří Szotkowski\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1129
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241017T140000
DTEND;TZID=Europe/Paris:20241017T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1127@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:An adaptive spectral element method for systems of conservation laws
DESCRIPTION:Manuel Colera Rico\n room:K3\n A novel method for the solution of systems of conservation laws is presented. For the space discretization, the scheme considers high-order continuous finite elements stabilized via subgrid modeling, as well as highly anisotropic adaptive meshes in order to capture any sharp features in the solution with the minimum number of mesh elements. Time integration is carried out via linearly implicit formulas, which allow for large time steps and require only the solution of a few linear systems per solved time interval. Furthermore, the mesh is adapted before solving for the next time interval, and not afterwards as in the common procedure, so as to avoid having to iteratively solve for the time interval until a valid mesh is generated. Numerical experiments, which include a hard case of nonconvex flux and the Euler equations for compressible flows, were performed with up to 8-th degree elements and a third-order time marching formula in order to assess the capabilities of the method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1127
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241010T140000
DTEND;TZID=Europe/Paris:20241010T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1126@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Winter semester kick-off
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1126
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20241003T140000
DTEND;TZID=Europe/Paris:20241003T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1125@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Krylov subspace recycling for matrix functions
DESCRIPTION:Liam Burke\n room:K3\n I will discuss a new augmented Krylov subspace method which allows for the efficient evaluation of a sequence of matrix function applications on a set of vectors using Krylov subspace recycling. If selected appropriately, the recycling subspace can be used to accelerate the convergence of each problem in the sequence, leading to an overall reduction in the computational overhead required to evaluate the full sequence of function applications, in comparison to standard Krylov subspace methods. Our new algorithm exploits the technique of randomized sketching in order to avoid excessive orthogonalization costs.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1125
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240523T140000
DTEND;TZID=Europe/Paris:20240523T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1122@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Decay properties of matrix functions: the influence of polynomial approximation and eigenvalue distribution
DESCRIPTION:Michele Rinelli\n room:K1\n  Matrix functions of the form f(A) are often encountered in numerical linear algebra and applied sciences. In many applications, the matrix argument A is sparse, i.e., among all the entries, only a few are nonzeros. Usually, even if A is sparse, f(A) is actually a dense matrix. However, it is often observed a decay when moving away from the main diagonal, or with respect to the sparsity pattern of A. In such case, we are able to approximate the matrix function with a sparse matrix, up to an error that depends on the decay rate, potentially leading to huge computational savings. In this seminar, we delve into the relation between the decay properties of f(A) and the best uniform polynomial approximations of f over a suitable set containing the spectrum of A. We consider in detail some specific matrix functions, such as the inverse and the sign. We explore the influence of the eigenvalue distribution of A on the decay, showing that the contribution of isolated eigenvalues is negligible, and predicting a superexponential decay for certain clustered spectra.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1122
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240516T140000
DTEND;TZID=Europe/Paris:20240516T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1124@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special Master's student seminar
DESCRIPTION:Václav Kučera\n room:K2\n Tomáš Hammerbauer: Domain decomposition methods for the solution of partial differential equations using discontinuous Galerkin method; Jakub Hercík: Detection and Correction of Silent Errors in Pipelined Krylov Subspace Methods
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1124
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240509T140000
DTEND;TZID=Europe/Paris:20240509T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1123@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special Ph.D. student seminar
DESCRIPTION:Dorota Šimonová, Ioannis Thanasis\n room:K1\n Dorota Šimonová: Mathematical model of block Lanczos computations, Ioannis Thanasis:The Algebraic Symmetric Eigenvalue Problem, GPUs and Mixed Precision
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1123
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240502T140000
DTEND;TZID=Europe/Paris:20240502T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1121@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Homogeneous multigrid for hybrid discretizations: application to HHO methods
DESCRIPTION:Andreas Rupp\n room:K1\n We prove the uniform convergence of the geometric multigrid V-cycle for hybrid high-order (HHO) and other discontinuous skeletal methods. Our results generalize previously established results for HDG methods, and our multigrid method uses standard smoothers and local solvers that are bounded, convergent, and consistent. We use a weak version of elliptic regularity in our proofs. Numerical experiments confirm our theoretical results.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1121
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240425T140000
DTEND;TZID=Europe/Paris:20240425T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1120@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:From `standard' to `nonstandard’ Krylov subspace methods for regularisation
DESCRIPTION:Silvia Gazzola\n room:K1\n This talk is about some so-called `hybrid projection methods’, i.e., regularisation methods that combine iterative regularisation methods (such as Krylov subspace methods) and variational regularisation methods. Hybrid projection methods based on some standard Krylov subspace methods (such as LSQR , LSMR, and GMRES ) and standard Tikhonov regularisation are well-established for linear inverse problems. The emphasis of this talk will be on novel hybrid projection methods that (1) exploit flexible Krylov subspace methods coupled with some generic p-norm regularization, or (2) exploit inexact Krylov subspace methods to handle separable nonlinear inverse problems.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1120
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240418T140000
DTEND;TZID=Europe/Paris:20240418T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1119@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A non-linear inverse problem of estimating the functional pore size distribution of porous media using non-newtonian fluids
DESCRIPTION:Martin Lanzendörfer\n room:K1\n We will review two recent methods of non-Newtonian porosimetry, both based on an intuitive capillary bundle idealisation of porous media for a saturated flow of non-Newtonian fluids. One is using the yield stress fluid rheology (the yield stress method, YSM), the other one is using the shear-thinning fluid model (method by Abou Najm and Atallah, the ANA method), but both methods are based on the same principles (and are even using the same real fluid in practical implementation). The non-linear response of the fluid may allow for a set of flow experiments (observations) with varying distribution of the total flux among pores of different size. An inverse problem can be invoked in order to estimate the pore size distribution from the observed total fluxes.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1119
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240411T140000
DTEND;TZID=Europe/Paris:20240411T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1118@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Spectral/hp Element Method and its application in fluid dynamics
DESCRIPTION:Jan Pech\n room:K1\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1118
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240404T140000
DTEND;TZID=Europe/Paris:20240404T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1117@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Kinetic Monte Carlo simulations in nanoscience: from molecules to single charges
DESCRIPTION:Pavel Kocán\n room:K3\n Material research at nanoscale has reached the point where we can study individual atoms, molecules or even individual charges. I will provide an overview of our approach, which relies on the application of kinetic Monte Carlo (kMC) simulations to interpret experimental data at the frontier of current possibilities. Growth of one-dimensional atomic chains on silicon surface will serve as an illustrative example [1,2], followed by field-driven self-assembly of organic molecules on weakly interacting surfaces [3,4]. As a more recent problem, I will present application of kMC to ion relaxation in cleaved muscovite mica [5], which helped to understand its atomic structure. Finally, I will discuss how kMC simulations have helped us explain the kinetics of polarons – charges trapped in the ionic lattice of a dielectric material. In all cases mentioned, kMC simulations enabled identification of the important processes and provided values of kinetic parameters by constructing a suitable minimal model. [1] Kocán P, Jurczyszyn L, Sobotík P, Ošt'ádal I. Defects on the Si ( 100 ) − ( 2 × 1 ) surface: Anchoring sites of the surface polymerization reaction of In atoms. Phys. Rev. B 2008 77(11). [2] Kocán P, Sobotík P, Ošt'ádal I, Setvín M, Haviar S. Modeling growth of one-dimensional islands: Influence of reactive defects. Phys. Rev. E. 2009 80(6):061603. [3] Matvija P, Rozbořil F, Sobotík P, Ošťádal I, Pieczyrak B, Jurczyszyn L, et al. Electric-field-controlled phase transition in a 2D molecular layer. Scientific Reports. 2017 7(1):7357. [4] Matvija P, Rozbořil F, Sobotík P, Ošt'ádal I, Kocán P. Pair Correlation Function of a 2D Molecular Gas Directly Visualized by Scanning Tunneling Microscopy. J Phys Chem Lett. 2017 8(17):4268–72. [5] Franceschi G, Kocán P, Conti A, Brandstetter S, Balajka J, Sokolović I, et al. Resolving the intrinsic short-range ordering of K+ ions on cleaved muscovite mica. Nat Commun. 2023 14(1):208.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1117
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240328T140000
DTEND;TZID=Europe/Paris:20240328T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1116@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Modular Topology Optimization of Complaint Structures and Mechanisms: Where Free-Material and Topology Optimizations Meet
DESCRIPTION:Jan Zeman\n room:K3\n The modular design approach has gained considerable interest due to its potential to efficiently address manufacturing, reusability, and sustainability while maintaining performance comparable to its traditional non-modular counterparts. However, designing such products is a challenging task that involves solving an optimization problem on two levels. First, modules must be optimally distributed within a product-scale domain. Second, the topology of individual modules must be optimized to ensure that they work together seamlessly when assembled. Addressing both problems simultaneously is considerably more complex, as it involves the intricate interplay of discrete and continuous features of the problem. In our previous work on the minimum compliance design of modular truss structures, we adopted a concurrent approach, combining a metaheuristic method for updating the modular assembly plan with second-order cone programming to generate optimal truss-like module topologies. However, this approach relied on a convex formulation, which limited its applicability. We now present a computationally more efficient bi-level sequential strategy that bypasses the need for assembly-level metaheuristics and is applicable to continuum structures and mechanisms. In addition, we incorporate manufacturing constraints using a three-field approach and continuity constraints. Our new approach starts with free material optimization on a modular grid. This step yields optimal, element-wise constant stiffness tensors. We then partition these stiffness tensors into a predetermined number of clusters, taking into account any underlying symmetries. Interpreting the clustering results in terms of the Wang tiling formalism yields the assembly plan, where individual codes on module edges reflect the similarity among the optimized stiffness tensors. Finally, the topology of individual modules is determined by standard single-scale topology optimization, with the design space reduced by a mapping that reflects the modular assembly plan. We demonstrate the efficiency of our strategy on four two-dimensional problems, including the modular minimal conformal Messerschmitt-Bölkow-Blohm beam, two modular conformal mechanisms (an inverter and a gripper), and a combined modular design of both mechanisms. The last example was also successfully validated in mechanical testing utilizing an in-house testing machine and digital image correlation. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1116
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240321T140000
DTEND;TZID=Europe/Paris:20240321T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1115@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Equivariance and Invariance in Neural Networks
DESCRIPTION:Filip Šroubek, Tomáš Karella\n room:K1\n In the rapidly evolving field of neural networks, achieving robustness against various geometric and radiometric transformations like rotation, scale, noise, or blur is crucial. This seminar begins by exploring why this robustness is important and how it is traditionally addressed through training neural networks with augmented datasets. We will define and differentiate between two key concepts: invariance, where the neural network output remains constant despite transformations to the input, and equivariance, a property where transformations to the input result in similar transformations in the output. The seminar will delve into the advantages of equivariance in neural networks, particularly its efficiency in encoding features and the ability to achieve enhanced performance with fewer parameters. Participants will leave with a deeper understanding of these concepts and their practical implications in the field of neural networks.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1115
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240314T140000
DTEND;TZID=Europe/Paris:20240314T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1114@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The star approach: from mathematical theory to numerical method
DESCRIPTION:Niel Van Buggenhout\n room:K3\n In 2015 an new analytical expression for the time-ordered exponential was proposed. The time-ordered exponential is the solution of system of ODEs and appears in many chemistry and physics problems, such as nuclear magnetic resonance spectroscopy. Starting from this expression, we developed a numerical method for approximating the time-ordered exponential. In this presentation we will describe the steps that were taken in order to obtain an efficient numerical method. That is, discretization of the expression, error-controlled truncation of the resulting discretized problem, and efficiently solving the truncated discretized problem.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1114
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240307T140000
DTEND;TZID=Europe/Paris:20240307T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1113@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:What is interesting about electron collisions with molecules and how to treat them numerically
DESCRIPTION:Martin Čížek\n room:K3\n I will review the experimental and theoretical results for studying processes induced by electron collisions with molecules, with a short overview of the contribution of our group in this field. I want also briefly mention the application of the processes in nanotechnology, laser-physics, radiation medicine and understanding of the plasma environments in atmospheres of various space bodies (comets, planets, stars) and in interstellar space. Then I try to explain some details of the numerical treatment of the processes within the quantum scattering theory. The talk will be concluded by gallery of our recent results and few notes on the future plans.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1113
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240229T140000
DTEND;TZID=Europe/Paris:20240229T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1112@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:New methods for recognizing blurred images
DESCRIPTION:Matěj Lébl\n room:K1\n Blur is among the most common degradations encountered in image acquisition. In computer vision tasks, it greatly reduces the success rate of any recognition method. In the handcrafted methods space blur is mostly handled by restoration - via deblurring, blur-invariant descriptors or blur invariant distances. In deep learning, degradations are almost exclusively dealt with by augmenting the training dataset. My doctoral Thesis covers three out of the four areas - it expands and generalize moment-based blur invariants, introduces new blur invariant measure and proposes a novel convolutional network architecture which is invariant to degradations alleviating the need for dataset augmentation.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1112
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240222T140000
DTEND;TZID=Europe/Paris:20240222T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1111@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Mixed Precision Linear Algebra Algorithms
DESCRIPTION:Yuxin Ma\n room:K1\n Mixed precision algorithms have been developed to utilize several floating-point arithmetic formats. Some of these algorithms aim to use a higher precision to improve the accuracy of an algorithm; others provide results of the same quality as algorithms running in a fixed precision but at a much lower cost. In recent years, since lower precision arithmetic is in general faster than higher precision arithmetic especially in GPU, it has attracted a lot of attention to use lower precision to improve the performance.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1111
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240111T140000
DTEND;TZID=Europe/Paris:20240111T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1110@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special student seminar
DESCRIPTION:Anwesh Pradhan, Manoj Prakash\n room:K3\n Analysis of a Non-Local Cahn Hilliard Equation using Finite Element Methods (Anwesh Pradhan), Analytical study of Rayleigh-Plesset equations arising in bubble dynamics (Manoj Prakash)
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1110
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20240104T140000
DTEND;TZID=Europe/Paris:20240104T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1109@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Some numerical questions in mathematical modeling of drug-induced gene induction
DESCRIPTION:Jurjen Tebbens\n room:K3\n The talk consists of an introduction in the most popular mathematical models used to describe the action of drug-activated DNA transcription factors. Starting from the standard types of relevant kinetic reaction equations, it presents corresponding systems of ODEs and PDEs and discusses their numerical solution. It is planned to address in particular numerical integration, sensitivity, identifiability and observability of parameters and quasi-steady-state assumptions.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1109
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231221T140000
DTEND;TZID=Europe/Paris:20231221T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1108@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Monte Carlo Method for Particle Transport
DESCRIPTION:Josef Martínek\n room:K3\n The problem of particle transport emerges for example in photoacoustic imaging or in criticality problems in nuclear reactors. This type of transport is governed by the so-called radiative transport equation (RTE). We present and compare several numerical methods for its solution, including the diffusion approximation or the Monte Carlo method. The mesh-based Monte Carlo method is studied more closely and the potential for its convergence analysis is explored.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1108
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231214T140000
DTEND;TZID=Europe/Paris:20231214T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1107@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Error analysis of a discontinuous Galerkin method for degenerate parabolic equations
DESCRIPTION:Sunčica Sakić\n room:K3\n In this talk, we present an error analysis for the spatial discretization of Richards’ equation, which is widely used in porous media flow modeling. Richards’ equation is a doubly nonlinear parabolic partial differential equation that can degenerate into an elliptic or ordinary differential equation. Therefore, it is challenging to develop and analyze a sufficiently accurate and efficient method for its numerical solution. We transform the original problem using an expanded mixed formulation and define the local discontinuous Galerkin method to discretize the spatial variable while the temporal variable remains continuous. We derive error estimates in terms of the Holder coefficient of nonlinear temporal derivative function and spatial discretization parameter. Moreover, we support the theoretical results by numerical experiments.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1107
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231207T140000
DTEND;TZID=Europe/Paris:20231207T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1106@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Linear matrix equations with applications to the numerical solution of certain PDEs
DESCRIPTION:Davide Palitta\n room:K3\n In the last years, it has been shown that the discretization of many partial differential equations (PDEs) can be recast in terms of a matrix equation which can indeed successfully replace its more common linear system formulation. We show that this is the case, for instance, for certain elliptic, parabolic, and hyperbolic PDEs. The matrix equation formulation of the discrete problem presents several computational advantages when compared to its linear system counterpart. In this seminar we are going to present these peculiar features and overview state-of-the-art solvers for such algebraic problems for both the small-case and large-scale settings.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1106
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231130T140000
DTEND;TZID=Europe/Paris:20231130T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1104@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Ensuring the Correctness of  Computational Results by Making Them Independently Checkable
DESCRIPTION:Stefan Ratschan\n room:K3\n A wide-spread method for ensuring correctness of mathematical software is based on transparency: lay open the code itself, the underlying algorithms, mathematical analysis, and proofs. This may be very useful, but in some contexts not possible, for example, due to proprietary code. It may also not be economical, for example, due to sheer size and complexity of the involved code and mathematical arguments. In the talk I will discuss examples of how such problems can be avoided by making computational results independently checkable, ensuring their correctness without any dependence on the way they were actually obtained.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1104
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231123T140000
DTEND;TZID=Europe/Paris:20231123T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1103@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:CLASSIX: Towards fast and scalable clustering
DESCRIPTION:Xinye Chen\n room:K3\n Clustering is an important task in the data science and machine learning community, with numerous applications in domains such as bioinformatics and astronomy. In this talk, we present a practically improved sorting-based density clustering called CLASSIX. The nature of the algorithm design enables early stopping criteria and BLAS routines, which allows for faster clustering procedures against the existing clustering methods. This talk will illustrate the algorithm as well as its software design in Python and Matlab, and detail its explainability in clustering. We demonstrate its capability over tasks from various domains, e.g., image clustering, in terms of adjusted mutual information and runtime, which showcase CLASSIX's superiority over other most widely used clustering methods. Last but not least, we present the interaction between Python and MATLAB development for CLASSIX.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1103
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231116T140000
DTEND;TZID=Europe/Paris:20231116T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1102@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Randomized matrix approximation in mixed precision
DESCRIPTION:Ieva Daužickaité\n room:K3\n The task of approximating a matrix arrises in various settings, including constructing preconditioners for iterative solvers. Throughout the past decade a lot of effort went into developing randomized techniques that can achieve this goal efficiently. Another rising trend in scientific computing is the use of mixed precision. We thus ask a natural question if we can compute the randomized matrix approximations in mixed precision and obtain high performance and suitable accuracy. In this talk, we consider randomized mixed precision algorithms for approximating a symmetric positive definite matrix, and computing a QR decomposition, and discuss how these can be used in preconditioning Krylov subspace solvers.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1102
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231109T140000
DTEND;TZID=Europe/Paris:20231109T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1101@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Vortex identification methods
DESCRIPTION:Marek Pátý\n room:K3\n Vortices belong to the most fundamental flow structures in fluid dynamics. They can improve airflow around an F1 car, aid combustion in jet engines, but also cause a bridge to collapse or demolish entire towns. Their importance in fluid flows has been known to us for a long time, as evidenced by Leonardo da Vinci's drawings of vortices in the aorta. Even a small child has an intuitive understanding of what a vortex is, yet there is no universally accepted rigorous mathematical definition. The ambition of this talk is to introduce the concept of a vortex and provide a brief overview of methods used for its identification and description.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1101
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231102T140000
DTEND;TZID=Europe/Paris:20231102T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1105@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Dean's Sports Day - seminar cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1105
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231026T140000
DTEND;TZID=Europe/Paris:20231026T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1100@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seismic waves as a tool for studying the Earth’s structure and earthquakes
DESCRIPTION:Václav Vavryčuk\n room:K3\n The seminar is devoted to theory of seismic waves and its application to numerical modelling of wave propagation in real geological structures. A particular focus will be devoted to the mathematical description of various types of seismic waves and associated wave phenomena, such as the wave scattering, generation of caustics and triplications of wavefronts. Furthermore, a mathematical description and numerical modelling of fracture processes in the earthquake source producing seismic waves will be discussed together with various methods of studying the Earth's structure using seismic methods. The applicability of the presented numerical methods will be demonstrated on several case studies taken from local, regional and global seismology.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1100
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231019T140000
DTEND;TZID=Europe/Paris:20231019T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1099@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Computer-aided characterization of catalytic filters in automotive exhaust gas aftertreatment
DESCRIPTION:Martin Isoz\n room:K3\n The EURO 6c norm, valid since 2017, requires both the gasoline and diesel combustion engines to be equipped with both catalytic converters for the abatement of gaseous pollutants and filters that trap the particulate matter (PM). This EURO 6c requirement resulted in combining structurally similar catalytic converters and PM filters into a single device, the catalytic filter (CF). The catalytic filter is a cylindrical monolith with a large number of alternately-plugged parallel channels in a honeycomb arrangement. The monolith walls are porous, and the catalytic material is deposited both inside and on them. As a device, CF has favorable properties with respect to the overall heat loss of the exhaust gas aftertreatment system and facilitates the system regeneration. However, the device's properties are strongly dependent on the catalytic material distribution within it. In this talk, we will present a multiscale and multiphysics numerical framework for computational characterization of the catalytic filter fundamental characteristics, i.e., pressure loss, conversion of gaseous pollutants, and PM filtration efficiency. The framework is built on the open-source finite-volume library OpenFOAM modified to allow for (i) the use of real-life CF geometry obtained via X-ray tomography, (ii) simulating nonisothermal heterogeneously catalyzed reactions, and (iii) coupling Lagrangian particle tracking algorithms with PM deposition in a Eulerian computational mesh. An emphasis will be placed on the architecture of the used solvers, and computational points.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1099
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231012T140000
DTEND;TZID=Europe/Paris:20231012T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1098@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A posteriori error analysis for discontinuous Galerkin methods on polygonal and polyhedral meshes
DESCRIPTION:Zhaonan Dong\n room:K3\n PDE models are often characterised by local features such as solution singularities/layers and domains with complicated boundaries and phase transitions. These special features make the design of accurate numerical solutions challenging or require a huge amount of computational resources. One way of achieving complexity reduction of the numerical solution for such PDE models is to design novel numerical methods which support general meshes consisting of polygonal/polyhedral elements, such that local features of the model can be resolved efficiently by adaptive choices of such general meshes. In this talk, we will present recent results on a new a posteriori error analysis for the dG method on general computational meshes consisting of polygonal/polyhedral (polytopic) elements with an arbitrary number of tiny faces. The new a posteriori error analysis first appeared in the literature and generalizes the known results for dG methods to admit an arbitrary number of irregular hanging nodes per element. Moreover, under certain practical mesh assumptions, the new error estimator of the dG method was proven to be available to incorporate essentially arbitrarily-shaped elements with an arbitrary number of faces or even curved faces. Finally, we will present the a posteriori error estimator of the space-time dG method for solving the Allen-Cahn problem. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1098
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20231005T140000
DTEND;TZID=Europe/Paris:20231005T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1097@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Winter semester kick-off
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1097
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230525T100000
DTEND;TZID=Europe/Paris:20230525T113000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1096@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stability of time discretizations for semi-discrete high order schemes for time-dependent PDEs
DESCRIPTION:Chi-Wang Shu\n room:K3\n In scientific and engineering computing, we encounter time-dependent partial differential equations (PDEs) frequently. When designing high order schemes for solving these time-dependent PDEs, we often first develop semi-discrete schemes paying attention only to spatial discretizations and leaving time $t$ continuous. It is then important to have a high order time discretization to main the stability properties of the semi-discrete schemes. In this talk we discuss several classes of high order time discretization, including the strong stability preserving (SSP) time discretization, which preserves strong stability from a stable spatial discretization with Euler forward, the implicit-explicit (IMEX) Runge-Kutta or multi-step time marching, which treats the more stiff term (e.g. diffusion term in a convection-diffusion equation) implicitly and the less stiff term (e.g. the convection term in such an equation) explicitly, for which strong stability can be proved under the condition that the time step is upper-bounded by a constant under suitable conditions, the explicit-implicit-null (EIN) time marching, which adds a linear highest derivative term to both sides of the PDE and then uses IMEX time marching, and is particularly suitable for high order PDEs with leading nonlinear terms, and the explicit Runge-Kutta methods, for which strong stability can be proved in many cases for semi-negative linear semi-discrete schemes. Numerical examples will be given to demonstrate the performance of these schemes. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1096
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230518T140000
DTEND;TZID=Europe/Paris:20230518T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1093@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical solution of time-dependent PDEs by anisotropic $hp$-mesh adaptation
DESCRIPTION:Vít Dolejší\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1093
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230511T140000
DTEND;TZID=Europe/Paris:20230511T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1095@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Poroelasticity: mathematical modelling, numerical solution and applications
DESCRIPTION:Jan Stebel\n room:K3\n The interaction of flow and mechanics in porous media plays an important role in many applications such as geotechnics or computational biomechanics. The lecture is focused on the model of poroelasticity arising from the Biot consolidation theory. I will introduce the classical Biot system, give an overview of results on well-posedness and finite element approximation and present some solution techniques based on monolithic or splitting schemes and suitable preconditionings. Finally, an application to hydro-mechanics of fractured rock will be presented, which involves modelling of fracture network and nonlinear effects such as non-penetration contact conditions and stress-permeability relations.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1095
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230504T140000
DTEND;TZID=Europe/Paris:20230504T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1092@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:PDE/ODE-constrained optimization problems and their efficient numerical solution
DESCRIPTION:Pavel Strachota\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1092
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230427T140000
DTEND;TZID=Europe/Paris:20230427T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1094@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite element methods respecting the discrete maximum principle for convection-diffusion equations
DESCRIPTION:Petr Knobloch\n room:K3\n Convection-diffusion-reaction equations model the conservation of scalar quantities. From the analytic point of view, solution of these equations satisfy under certain conditions maximum principles, which represent physical bounds of the solution. That the same bounds are respected by numerical approximations of the solution is often of utmost importance in practice. The mathematical formulation of this property, which contributes to the physical consistency of a method, is called Discrete Maximum Principle (DMP). In many applications, convection dominates diffusion by several orders of magnitude. It is well known that standard discretizations typically do not satisfy the DMP in the convection-dominated regime. For this regime, it turns out to be a challenging problem to construct discretizations that, on the one hand, respect the DMP and, on the other hand, compute accurate solutions. We present a survey on finite element methods, with a main focus on the convection-dominated regime, that satisfy a local or a global DMP. The survey reveals that for the steady-state problem there are only a few discretizations, all of them nonlinear, that at the same time satisfy the DMP and compute reasonably accurate solutions. Methods based on algebraic stabilization, nonlinear and linear ones, are currently as well the only finite element methods that combine the satisfaction of the global DMP and accurate numerical results for the evolutionary equations in the convection-dominated situation.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1094
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230420T140000
DTEND;TZID=Europe/Paris:20230420T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1089@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar CANCELLED
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1089
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230413T140000
DTEND;TZID=Europe/Paris:20230413T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1091@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special student seminar
DESCRIPTION:Lukáš Vacek, Petr Vacek\n room:K3\n Theory and numerical solution of Godunov--like numerical fluxes for conservation laws on networks (Lukáš Vacek), Stopping Criteria for Coarsest-Grid Solver in Multigrid V-Cycle Method (Petr Vacek)
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1091
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230406T140000
DTEND;TZID=Europe/Paris:20230406T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1090@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special student seminar
DESCRIPTION:Prabhat Mishra, Hyun-Geun Shin\n room:K3\n Mesh adaptation and agglomeration techniques for time dependent partial differential equations (Prabhat Mishra), A posteriori error estimates for STDGM for solving the Richards equation (Hyun-Geun Shin) 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1090
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230330T140000
DTEND;TZID=Europe/Paris:20230330T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1086@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The X-MESH method for capturing interfaces
DESCRIPTION:Jonathan Lambrechts\n room:K3\n In this presentation, we introduce an innovative approach - X-MESH - to overcome a major difficulty associated with numerical simulation in engineering: we aim to provide a way to track physical interfaces in finite element simulations. The idea is to use so-called extreme mesh deformations. This new approach should allow low computational cost simulations as well as high robustness and accuracy. X-MESH is designed to avoid the pitfalls of current ALE methods by allowing topological changes on fixed mesh. The key idea of X-MESH is to allow elements to deform until they reach a zero measure. For example, a triangle can deform into an edge or even a point. This idea is rather extreme and completely revisits the interaction between the meshing community and the computational community, which for decades have been trying to interact through beautiful meshes. In this talk, we will focus on both the mathematical issues related to the use of zero-measure elements and the X-MESH resolution scheme. Several applications will be targeted: the Stefan model of phase change, two-phase flows and contact between deformable solids.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1086
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230323T140000
DTEND;TZID=Europe/Paris:20230323T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1088@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Least square function approximation
DESCRIPTION:Niel Van Buggenhout\n room:K3\n A function of interest is sometimes only known from measurement, the available data is then a set of points and corresponding function evaluations in these points. From this data an approximation to the function can be computed, a powerful and well-known technique to do this is least squares approximation. Usually the least squares approximant is constructed from simple basis functions, for example polynomials or rational functions. A naive formulation of the least squares problem, i.e., finding the optimal approximant, leads to a system of equations with a Vandermonde matrix. Such a system is usually ill-conditioned. We discuss how, for any given set of points, a well-conditioned system of equations can be formulated by exploiting the connections between least squares problems, Krylov subspace methods and orthogonal polynomials. We also discuss how to efficiently update or downdate the least square approximant if data is added to or removed from the currently available data.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1088
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230316T140000
DTEND;TZID=Europe/Paris:20230316T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1084@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Parallel-in-time preconditioners for ocean data assimilation
DESCRIPTION:Jemima Tabeart\n room:K3\n Correlation operators are used in data assimilation algorithms to weight the contribution of prior and observation information. Efficient implementation of these operators is therefore crucial for operational implementations. Diffusion-based correlation operators are popular in ocean data assimilation, but can require a large number of serial matrix-vector products. A parallel-in-time formulation removes this requirement, and offers the opportunity to exploit modern computer architectures. High quality preconditioners for the parallel-in-time approach are well-known, but impossible to apply in practice for the high-dimensional problems that occur in oceanography. In this talk we consider a nested preconditioning approach which retains many of the beneficial properties of the ideal analytic preconditioner while remaining affordable in terms of memory and computational resource.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1084
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230309T140000
DTEND;TZID=Europe/Paris:20230309T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1083@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:How nonlinear systems turn out to quasi-linear: Hommage to Ivo Marek  and M-matrices
DESCRIPTION:Štěpán Papáček\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1083
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230302T140000
DTEND;TZID=Europe/Paris:20230302T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1085@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Non-Stochastic Uncertainty Quantification with Applications
DESCRIPTION:Jan Chleboun\n room:K3\n In applying mathematical and computational models, uncertainty in model inputs and, consequently, in model outputs should be assessed. Although stochastic methods are probably most popular in uncertainty quantification (UQ), non-stochastic approaches can be advantageous in some situations. The lecture will focus on two of them, namely on fuzzy set theory and Dempster-Shafer theory. It will be shown that even elementary tools offered by these theories and supplemented by the finite element method and optimization methods enables us to design algorithms for UQ in problems driven by, for instance, differential equations. Little prior knowledge of mathematics is assumed; the lecture will be accessible to undergraduate students.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1085
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230223T140000
DTEND;TZID=Europe/Paris:20230223T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1087@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled - official semester kick-off party
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1087
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230216T140000
DTEND;TZID=Europe/Paris:20230216T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1082@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Virtual element methods for fourth-order problems
DESCRIPTION:Alice Hodson\n room:K3\n In recent years, the discretisation of partial differential equations via the virtual element method (VEM) has seen a rapid increase. The virtual element method is an extension of both finite element and mimetic finite difference methods. VEM spaces can be easily constructed to enforce desirable properties of the discrete functions even on general polygonal meshes, which makes the approach very appealing for a vast range of problems. The construction of even a lowest order C^1-conforming space is not straightforward within the standard finite element setting and higher order nonconforming spaces suitable for fourth-order problems are also not readily available. In this talk, we develop a generic approach for constructing the necessary projection operators, virtual element spaces, and discrete forms. We analyse these VEMs before looking at their application to a wide range of fourth-order problems.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1082
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20230105T140000
DTEND;TZID=Europe/Paris:20230105T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1079@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Vapor plume on Enceladus – a modelling journey there and back again.
DESCRIPTION:Ondřej Souček\n room:K3\n In this talk, we present our recent understanding of the activity of the vapor plume emanating from the south-polar region of Saturn's moon Enceladus. The discovery of the plume led to a skyrocketing increase of scientific interest in the moon as it brought evidence for the existence of its internal ocean and allowed for sampling of its composition. However, no satisfactory explanation has been provided so far concerning the observed timing of the plume activity. We present the results of our modeling effort in this regard combining a 3d visco-elasto-plastic model of the outer shell of the moon which includes Tiger stripes – cracks in the south polar region, a simplified hydrodynamic model of the water column dynamics in the cracks and a model of water vapor transport in the upper section of the crack. We discuss the capacity of the model to explain the mystery of Enceladus' plume activity timing.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1079
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221215T140000
DTEND;TZID=Europe/Paris:20221215T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1081@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On the Forsythe conjecture
DESCRIPTION:Petr Tichý\n room:K3\n Forsythe formulated a conjecture about the asymptotic behavior of the restarted conjugate gradient method in 1968. We translate several of his results into modern terms, and generalize the conjecture (originally formulated only for symmetric positive definite matrices) to symmetric and nonsymmetric matrices. Our generalization is based on a two-sided or cross iteration with the given matrix and its transpose. We prove several new results about the limiting behavior of this iteration, but the conjecture still remains largely open.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1081
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221201T140000
DTEND;TZID=Europe/Paris:20221201T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1080@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Analysis of pattern formation using numerical continuation
DESCRIPTION:Vladimír Janovský\n room:K3\n The contribution deals with the issue of self-organization in applied sciences. It is particularly related to the emergence of Turing patterns. The goal is to analyze the domain size driven instability: We introduce the parameter L, which scales the size of the domain. We investigate a particular reaction-diffusion model in 1-D for two species. We consider and analyze the steady-state solution. We want to compute the solution branches by numerical continuation. The model in question has certain symmetries. We define and classify them. Our goal is to calculate a global bifurcation diagram.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1080
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221124T140000
DTEND;TZID=Europe/Paris:20221124T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1076@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Iterated Gauss-Seidel Gram - Schmidt process
DESCRIPTION:Miroslav Rozložník\n room:K3\n We present an iterated Gauss-Seidel formulation of the GMRES algorithm (IGS-GMRES) based on the ideas of Ruhe (1983) and Swirydowicz et al. (2020). IGS-GMRES maintains orthogonality to the level O(eps) kappa(B) or O(eps), depending on the choice of one or two iterations; for two Gauss-Seidel iterations, the computed Krylov basis vectors remain orthogonal to working accuracy. The resulting GMRES method is thus backward stable. We show that IGS-GMRES can be implemented with only a single synchronization point per iteration, making it relevant to large-scale parallel computing environments. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1076
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221110T140000
DTEND;TZID=Europe/Paris:20221110T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1077@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:70 years of Krylov subspace methods
DESCRIPTION:Erin Claire Carson\n room:K3\n This year marks the 70th anniversary of the original paper on the conjugate gradient (CG) method by Hestenes and Stiefel. In honor of this anniversary, we recall the important mathematical properties of CG and present a collection of 10 essential examples that demonstrate the finer points of its mathematical and computational behavior. The goal of these examples is to show the mathematical beauty and hidden intricacies of CG, and to point out some persistent misunderstandings as well as important open problems.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1077
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221103T140000
DTEND;TZID=Europe/Paris:20221103T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1075@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finding vertex-disjoint cycle cover of undirected graph using the least-squares method
DESCRIPTION:Jan Lamač\n room:K3\n Finding a vertex-disjoint cycle cover (called a 2-factor) of a given undirected graph G consists in finding a set of disjoint cycles which are subgraphs of G and contain all vertices of G. It is well known that a 2-factor of an undirected 2-factorable graph can be found in polynomial time by transforming the problem into a problem of finding a perfect matching in a larger graph. When we prescribe further conditions on this cycle cover (e.g. number of components, minimal cycle length) the problem of finding a 2-factor becomes NP-hard. In the talk we investigate the properties of the least-squares solution of the system of equations with a matrix being the incidence matrix of the given undirected graph G and we propose an algorithm that uses this solution for finding a 2-factor of the graph G.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1075
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221027T140000
DTEND;TZID=Europe/Paris:20221027T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1073@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Bayes inversion for the properties of the excavation damage zone
DESCRIPTION:Jan Březina\n room:K3\n The excavation damage zone (EDZ) is one of the possible transport paths for the contaminants in the deep geological repositories of radioactive waste. Knowledge of its transport parameters, porosity and permeability in particular, is important for the safety analysis of the repository. We shall introduce a non-linear poroelastic model for the formation and evolution of EDZ. Experimental data from continual measurement of the pore pressure during excavation will be used to determine the statistical distribution of the model parameters using the Bayes inversion.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1073
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221020T140000
DTEND;TZID=Europe/Paris:20221020T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1078@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A parallel domain decomposition solver for immersed boundary finite element method
DESCRIPTION:Pavel Kůs\n room:K3\n A conforming mesh generation for large-scale finite element method calculations is often a computational bottleneck, especially in the case of complex geometries. Not only is it compute time demanding, but transforming a CAD model to a volumetric mesh with required properties might be a hard problem. Immersed boundary approaches are gaining popularity as they can circumvent the need for the creation of conforming mesh. In this presentation, we discuss the challenges of the use of immersed boundary FEM solver with adaptivity of the underlying mesh and parallel implementation of domain decomposition. We show the algorithmic treatment, the influence of this setting on load balancing, and show performance of our implementation using challenging engineering geometries.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1078
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221013T140000
DTEND;TZID=Europe/Paris:20221013T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1072@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Reliable two-sided bounds to all eigenvalues of preconditioned matrix
DESCRIPTION:Ivana Pultarová\n room:K3\n We consider a matrix A resulting from discretization of the weak form of an elliptic partial differential operator with variable tensor coefficient C and a preconditioning matrix $A_p$ obtained in the same way but with constant coefficient $C_p$. Any sensible boundary conditions can be applied. We present a method yielding reliable lower and upper bounds to all eigenvalues of $A_p^{-1}A$. In particular, we show how the bounds can be obtained from $C_p^{-1}C$. The discretization techniques such as finite element method, finite difference method, or stochastic Galerkin methods can be used.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1072
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20221006T140000
DTEND;TZID=Europe/Paris:20221006T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1071@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite element approximation of a nonlinear heat conduction problem in anisotropic media
DESCRIPTION:Michal Křížek\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1071
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220929T140000
DTEND;TZID=Europe/Paris:20220929T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1074@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled - official semester kick-off party
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1074
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220519T140000
DTEND;TZID=Europe/Paris:20220519T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1069@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A Modern Approach to Simulating Flight
DESCRIPTION:L. Ridgway Scott\n room:K3\n A new era in flight is emerging that requires a more effective simulation strategy. We describe an approach based on instabilities in flow. The method we use is an old but less used definition of instability that is more rigorous than what is commonly used. We show that our results correlate well with what can be observed by both experiment and direct numerical simulation.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1069
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220512T140000
DTEND;TZID=Europe/Paris:20220512T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1068@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Incomplete variants of the generalized Gram-Schmidt process in context
DESCRIPTION:Jiří Kopal\n room:K3\n System of linear algebraic equations with a symmetric and positive definite matrix arise from many areas in science and engineering. Although, direct solvers may deliver robust solution, iterative solver based on the conjugate gradient method (CG) is often method of choice. Efficiency of CG strongly depends on preconditioner, i.e., on our ability to approximate the inverse of the system matrix. It can be provided by incomplete algorithms. Well known are the variants of the incomplete Cholesky factorization, on the other hand backward/forward solve steps in every iteration may significantly limit performance of CG. The inverse preconditioners represent a counterpart to the direct ones. Their computation is in general more expensive, on the other hand, especially in parallel environment, their application can be very fast. We deal with incomplete algorithms based on the Gram-Schmidt orthogonalization with respect to non-standard inner product (induced by the system matrix). Incomplete algorithms employ techniques to preserve sparsity of the computed matrices. We will discuss how to exploit theoretical results to construct such techniques. In addition, numerical aspects will be accompanied by test problems.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1068
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220505T140000
DTEND;TZID=Europe/Paris:20220505T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1070@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1070
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220428T140000
DTEND;TZID=Europe/Paris:20220428T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1067@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Multigrid for high-order finite elements: line search, p-robustness, a posteriori estimates, and adaptivity
DESCRIPTION:Martin Vohralík\n room:K3\n We develop and analyze an iterative solver for large sparse systems of algebraic equations arising from finite element discretizations of high polynomial degree p. It is of multigrid type and has the following characterizations: (1) It is genuinely steered by an a posteriori estimator that certifies the algebraic error in the energy norm. (2) It contracts the algebraic error independently of the polynomial degree p. (3) It is basis independent. (4) The error descent is optimized by a line search on each mesh level. (5) It features an explicit Pythagorean formula for the decrease of the algebraic error along the iterations in terms of level-wise and patch-wise computable error reductions. (6) It is naturally non symmetric: first the roughest modes are captured by the coarse solve, and then smoothing, by additive Schwarz (block-Jacobi), is performed on each mesh level. (7) It is naturally minimalist: only one post-smoothing step is sufficient. (8) It is parameter-free (no damping or number of smoothing steps or other parameters need to be defined). (9) Adaptive number of smoothing steps and adaptive choice of patches to perform smoothing can be straightforwardly set up.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1067
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220421T140000
DTEND;TZID=Europe/Paris:20220421T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1066@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Clifford algebras in R^4: Computing zeros of polynomials
DESCRIPTION:Drahoslava Janovská\n room:K3\n We focus on some results in different types of Clifford algebras in R^4. After the brief (pre)historical overview, we will give the basic definitions for quaternions and coquaternions and compare their basic properties. We may observe many similarities in other algebras in R^4. In particular we will consider tessarines, cotessarines, nectarines, conectarines, tangerines, and cotangerines. We study the linear equations in quaternions and coquaternions. Based on the theory of companion polynomials, an algorithm was developed to calculate all roots of simple quaternionic polynomials of degree n. In general, quaternionic coefficients can be located on both sides of the powers. If so, there are even 5 different zero classes, that are classified according to the rank of a certain real 4x4 matrix. All results can be extended to other Clifford algebras in R^4.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1066
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220414T140000
DTEND;TZID=Europe/Paris:20220414T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1065@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Agglomeration and refinement of polytopic meshes for DGFEM and VEM
DESCRIPTION:Scott Congreve\n room:K3\n There has recently been significant work developing numerical methods to operate on meshes containing elements of arbitrary shape, so-called polytopic elements, such as polytopic discontinuous Galerkin finite element methods (DGFEM) and virtual element methods (VEM). One technique for constructing meshes of polytopic elements is to agglomerate existing meshes of standard elements. This technique is especially useful in the situations where multiple, hierarchical, meshes are required; e.g., for multiscale or multigrid methods. Existing methods for agglomeration either attempt to maintain element geometry, or are based on optimal graph splitting techniques of the dual graph for the mesh. However, meshes generated using these agglomeration techniques do not necessarily consider the a priori knowledge on the domain or method, and are not necessary guaranteed to meet the assumptions required by the numerical analysis of the methods being utilised. In this talk, we give a brief overview of some these problems, and the ideas we will explore as part of the forthcoming PRIMUS project to improve these agglomerations. Furthermore, we will briefly discuss ideas for adaptive mesh refinement of these agglomerated meshes.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1065
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220407T140000
DTEND;TZID=Europe/Paris:20220407T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1059@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical approximation of the spectrum of self-adjoint operators and operator preconditioning
DESCRIPTION:Zdeněk Strakoš\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1059
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220331T140000
DTEND;TZID=Europe/Paris:20220331T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1064@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Smoothed particle hydrodynamics for astrophysical simulations
DESCRIPTION:Pavel Ševeček\n room:K3\n The seminar will cover an introduction to the smoothed particle hydrodynamics, a Lagrangian method for computational fluid dynamics. The method does not require a predetermined computational domain and it is thus useful for astrophysical applications. Using the Lagrangian of the particle system, it is possible to derive a set of equations that conserves the total mass, linear and angular momentum, and energy. However, the discretized equations appear unstable or inaccurate in some physically relevant situations (shockwave propagation, material interface, solid body rotation, etc.), which can be mitigated by modifying the discretization or by including artificial terms. SPH allows us to implement additional physics in a straightforward way. For astrophysical simulations, the equations can be extended by self-gravitation, heat diffusion or radiative transfer. In particular, SPH is the method of choice for collision simulations of self-gravitating bodies, allowing to compute collisions with various equations of state and rheological models.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1064
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220324T140000
DTEND;TZID=Europe/Paris:20220324T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1063@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solving sparse-dense least squares
DESCRIPTION:Miroslav Tůma\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1063
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220317T140000
DTEND;TZID=Europe/Paris:20220317T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1058@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical solution of convection-dominated problems
DESCRIPTION:Petr Lukáš\n room:K3\n We will discuss approaches for adaptive choice of parameters in stabilization methods for convection-diffusion equations discretized by the finite element method. We introduce the L-SR1 method, compare it with other nonlinear methods of minimizing functions with a large number of variables, and introduce and compare adaptive methods based on minimizing a functional called error indicator.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1058
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220310T140000
DTEND;TZID=Europe/Paris:20220310T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1061@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Rate independent evolutions
DESCRIPTION:Martin Brokate\n room:K3\n We give an introduction to basic rate independent evolutions like those defined by the play and stop operator. We then discuss the question whether these operators, which are nonsmooth operators between suitable function spaces, have directional derivatives.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1061
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220303T140000
DTEND;TZID=Europe/Paris:20220303T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1062@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Computational challenges in numerical simulations of stably stratified flows
DESCRIPTION:Tomáš Bodnár\n room:K3\n The stratified flows are common physical phenomena typically found in many environmental and industrial problems. Although being studied for many decades and centuries, new problems associated with their solution by means of high resolution numerical methods arise in simulations of related practical problems. The talk will focus on some issues found while solving the wall bounded stably stratified flows under a range of Froude and Reynolds numbers. The problems of choice of suitable numerical methods, computational setup and selection of soft boundary conditions on artificial boundaries will be discussed in detail. Selected results of stably stratified flow over a 3D hill will be presented to demonstrate the main points of the talk.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1062
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220224T140000
DTEND;TZID=Europe/Paris:20220224T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1060@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical mathematics connecting Partial Differential Equations and Cellular Automata
DESCRIPTION:Jiří Felcman\n room:K3\n Numerical mathematics connecting Partial Differential Equations and Cellular Automata (CA) for a pedestrian evacuation simulation is presented. The crowd flow is considered in terms of compressible fluid flow such as density, velocity and pressure. The intended direction of the escape of pedestrians in panic situations is governed by the Eikonal equation of the pedestrian flow model. A new two-dimensional CA model is proposed for the simulation of the pedestrian flow. The solution of the Eikonal equation is used to define the probability matrix whose elements express the probability of a pedestrian moving in finite set of directions. The relevant evacuation scenarios are numerically solved. Predictions of the evacuation behavior of pedestrians, for various room geometries with multiple exits, are demonstrated. The mathematical model is numerically justified by comparison of CA approach with the Finite Volume Method for the space discretization and Discontinuous Galerkin Method for the implicit time discretization of pedestrian flow model. For a short overview of CA see https://mathworld.wolfram.com/CellularAutomaton.html
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1060
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220217T140000
DTEND;TZID=Europe/Paris:20220217T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1057@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Structured matrices in (rational) Krylov subspace methods
DESCRIPTION:Niel Van Buggenhout\n room:K3\n Structured matrices play a key role in the development of effective Krylov subspace methods and their theoretical study. Standard Krylov subspaces are built using consecutive powers of a matrix multiplied by a fixed vector.The associated structured matrices are well known, these are Hessenberg and tridiagonal matrices. In recent years there has been a growing interest in rational Krylov subspaces. Rational Krylov subspaces allow multiplication with a matrix and with a shifted and inverted version of this matrix. This freedom allows more flexibility than the standard Krylov subspaces. For example, in eigenvalue computation rational Krylov subspace methods allow us to specify different regions of interest throughout the whole complex plane. This can speed up the convergence of Ritz values to eigenvalues within these regions. Before any successful numerical methods can be developed, it is necessary to have a theoretical framework. This seminar will focus on identifying all possible matrix structures that can occur in the context of rational Krylov subspaces. The main result shows that a tridiagonal matrix pencil suffices to represent biorthonormal bases for any rational Krylov subspace. This leads to a rational generalization of the Lanczos iteration. As an application of the developed theory, novel methods are discussed to generate (formal) orthogonal polynomials and (bi)orthogonal rational functions.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1057
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220106T140000
DTEND;TZID=Europe/Paris:20220106T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1056@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Randomised preconditioning for variational data assimilation
DESCRIPTION:Ieva Daužickaitė\n room:K3\n Data assimilation provides an improved estimate of a state of a dynamical system by combining a previous estimate with observations of the system. Large sparse linear systems of equations arise in a weak constraint four-dimensional variational data assimilation method. Iterative solvers are used, and preconditioning is essential to improve their performance. We consider four formulations of linear systems, particularly a symmetric positive definite (SPD) system arising in the so-called forcing formulation, and an SPD and two saddle point systems arising in the so-called state formulation; these exhibit different possibilities for parallel computations and sensitivities to the number of observations. Randomised methods for low-rank matrix approximations are used to construct suitable preconditioners for each system of equations. Numerical results with toy models show that the preconditioners can be effective.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1056
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211216T140000
DTEND;TZID=Europe/Paris:20211216T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1055@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar canceled
DESCRIPTION:\n room:\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1055
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211209T140000
DTEND;TZID=Europe/Paris:20211209T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1054@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Preconditioning the Stage Equations of Implicit Runge Kutta Methods
DESCRIPTION:Michal Outrata\n room:K3\n When using implicit Runge-Kutta methods for solving parabolic PDEs, solving the stage equations is often the computational bottleneck, because the dimension of the stage equations is related to the spatial discretization and can thus become very large. The solution of the stage equations hence often requires the use of iterative solvers, whose convergence can be less than satisfactory. Using spectral analysis, we study the properties of two recently introduced preconditioners for the stage equations, and their dependence on the associated Butcher tableau of the Runge-Kutta method. We then try to optimize the Butcher tableau for the performance of the entire solution process, rather than only the order of convergence of the Runge-Kutta method. To do so requires to carefully balance the numerical stability of the Runge-Kutta method, its order of convergence, and also the convergence of the iterative solver for the stage equations. We illustrate our result on a simple test problem and then outline possible generalizations.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1054
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211202T140000
DTEND;TZID=Europe/Paris:20211202T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1053@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Computer-assisted proofs of existence of periodic motions in fluids
DESCRIPTION:Jean-Philippe Lessard\n room:K3\n In the study of infinite dimensional dynamical systems exploring the dynamics in the entire phase space is impossible. One strategy to tackle this problem is to focus on a set of special solutions that act as organizing centers. To single out these solutions computer-assisted proofs are being developed to find, for example, fixed points, periodic orbits and connecting orbits between those. Computer-assisted proofs in dynamics combine the strength of scientific computing, nonlinear analysis, numerical analysis, applied topology, functional analysis and approximation theory. While in the past decade, these techniques have primarily been applied to ODEs, we are starting to witness their applicability for infinite dimensional nonlinear dynamics generated by partial differential equations (PDEs), integral equations, delay differential equations (DDEs), and infinite dimensional maps. In this talk we will present recent advances in this direction, with a special emphasize on the dynamics in the Navier-Stokes equations.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1053
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211125T140000
DTEND;TZID=Europe/Paris:20211125T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1049@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Acceleration of FFT-based homogenisation by low-rank tensor approximations
DESCRIPTION:Martin Ladecký\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1049
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211118T140000
DTEND;TZID=Europe/Paris:20211118T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1052@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Validation of CFD models – an experimentalist’s view
DESCRIPTION:Klára Jurčáková\n room:K3\n The presentation will show a current praxis of CFD model validation for turbulent flow, namely atmospheric flow. The evaluation of these models is usually performed with the use of laboratory data. We will introduce a principle of wind tunnel modeling of the atmospheric boundary layer, measurement techniques, and the method limitations. The validation of the large-eddy simulation model against the wind tunnel data within a street canyon will be shown.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1052
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211111T140000
DTEND;TZID=Europe/Paris:20211111T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1051@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Estimating algebraic error using flux reconstructions
DESCRIPTION:Jan Papež\n room:K3\n We will present error estimators that use a unified framework to bound from above the total and the algebraic errors in numerical solution of PDEs. The estimators involve no unknown or uncomputable factors and allow to estimate the local distribution of the errors in the solution domain. They are based on so-called quasi-equilibrated flux reconstruction and we will detail its construction. The numerical results will be presented to demonstrate very good behaviour of the estimator. On the other hand, we admit that the flux reconstruction is a complex procedure and the evaluation of the error estimator can be costly. We will therefore present also few ideas how to reduce the evaluation cost.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1051
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211104T140000
DTEND;TZID=Europe/Paris:20211104T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1047@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special student seminar
DESCRIPTION:Noaman Khan, Eda Oktay, Shazma Zahid\n room:K3\n Three new PhD students of the Department of Numerical Mathematics will introduce themselves, their thesis topics and their previous work. Noaman Khan: Inexact Preconditioning in Iterative Methods, Eda Oktay: Mixed-Precision in Numerical Linear Algebra, Shazma Zahid: Introducing Myself.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1047
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211021T140000
DTEND;TZID=Europe/Paris:20211021T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1046@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solution strategy for Richards' equation based on Discontinuous Galerkin methods and adaptive mesh refinement
DESCRIPTION:Jean-Baptiste Clément (Université de Montpellier)\n room:K3\n Richards' equation describes flows in variably saturated porous media. Its solution is challenging since it is a parabolic equation with nonlinearities and degeneracies. In particular, many real-life problems are demanding because they can involve steep/heterogeneous hydraulics properties, dynamic boundary conditions or moving sharp wetting fronts. In this regard, the aim is to design a robust and efficient numerical method to solve Richards' equation. Towards this direction, the work presented here deals with Discontinuous Galerkin methods which are very flexible discretization schemes. They are combined with BDF methods to get high-order solutions. Built upon these desirable features, an adaptive mesh refinement strategy is proposed to improve Richards' equation simulations. Examples such as the impoundment of a multi-material dam or the groundwater dynamics of sandy beaches illustrate the abilities of the approach.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1046
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211014T140000
DTEND;TZID=Europe/Paris:20211014T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1050@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Low-Mach consistency of a class of linearly implicit schemes for the compressible Euler equations
DESCRIPTION:Václav Kučera\n room:K3\n The semi-implicit discontinous Galerkin scheme of Feistauer, Dolejší and Kučera works surprisingly well for the computation of low-Mach compressible flows without performing any special modifications of the numerical flux or other 'tricks' deemed necessary by the low-Mach community. This was demonstrated numerically nearly 20 years ago. Now we finally have a theoretical justification in the form of a proof of asymptotic consistency of a more general class of linearly implicit schemes.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1050
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20211007T140000
DTEND;TZID=Europe/Paris:20211007T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1045@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A Lanczos-like method for the time-ordered exponential
DESCRIPTION:Stefano Pozza\n room:K3\n The time-ordered exponential (TOE) is defined as the function that solves a system of coupled first-order linear differential equations with generally non-constant coefficients. Despite being at the heart of many problems, the TOE remains elusively difficult to evaluate. The path-sums method formulates any desired entry of a TOE as a branched continued fraction of finite depth and breadth, and it has been successfully used to solve challenging quantum dynamic problems. However, while this approach can provide exact (even analytical) expressions and is unconditionally convergent, it suffers from a complexity drawback. It requires finding all the simple cycles and simple paths of a certain graph G, an #P-complete task. The ⋆-Lanczos algorithm solves this issue by effectively mapping G on a structurally simpler graph. On this graph, the path-sum solution takes the form of an ordinary, finite, continued fraction.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1045
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210930T140000
DTEND;TZID=Europe/Paris:20210930T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1048@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar canceled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1048
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210527T140000
DTEND;TZID=Europe/Paris:20210527T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1044@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Special student seminar
DESCRIPTION:Jan Dvořák, Shahin Heydari, Sunčica Sakić, Hyun-Geun Shin, Lukáš Vacek\n room:Online via Zoom\n Five students from the Department of Numerical Mathematics will briefly present their current work, or in the case of new students, previous work and experiences. The titles of the individual talks are: Jan Dvořák: Properties and construction of core problem in data fitting problems with multiple observations. Shahin Heydari: FCT scheme for evolutionary convection-diffusion-reaction equations with small diffusion. Sunčica Sakić: Numerical solution of PDE describing porous media flow. Hyun-Geun Shin: Research Journey as a Korean. Lukáš Vacek: Theory and numerical solution of traffic flow models on networks.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1044
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210513T140000
DTEND;TZID=Europe/Paris:20210513T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1042@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Subspace Method for Approximation of H-infinity Norms of Large-Scale Control Systems
DESCRIPTION:Nicat Aliyev\n room:Online via Zoom\n I will shortly describe and formulate the problem of the computation of H-infinity norm of a given control system such as descriptor system or time-delay system. Then, I will review some existent methods in literature. Afterward, I will introduce our subspace method and explain how to employ it to approximate the H-infinity or more generally L-inifnity norm of large-scale control systems. I will give the main result which states that our subspace method converges superlinearly assuming that it converges at least locally. Finally, I will demonstrate several numerical results that verify the fast convergence and efficiency of our method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1042
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210429T140000
DTEND;TZID=Europe/Paris:20210429T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1041@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Connection of deep neural networks to differential equations
DESCRIPTION:Petr Šimánek\n room:Online via Zoom\n Short review of deep neural networks (DNN) with emphasis on used mathematical methods. Applications of DNNs for the solution of differential equations and analysis of DNNs with differential equations will be briefly reviewed. Some results in weather forecasting and learned gradient optimization methods will be presented.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1041
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210422T140000
DTEND;TZID=Europe/Paris:20210422T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1043@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Learning with the graph Laplacian: from PDEs to data science
DESCRIPTION:Martin Stoll (TU Chemnitz)\n room:Online via Zoom\n In this talk we briefly review some basic PDE models that are used to model phase separation in materials science. They have since become important tools in image processing and semi-supervised learning. The main ingredient is the graph Laplacian that stems from a graph representation of the data. This matrix is large and typically dense. We illustrate some of its crucial features and show how to efficiently work with the graph Laplacian. In particular, we need some of its eigenvectors and for this the Lanczos process needs to be implemented efficiently. Here, we suggest the use of the NFFT method for evaluating the matrix vector products without even fully constructing the matrix. We have recently applied this technique in combination with a multilayer graph or time-series classification.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1043
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20210401T140000
DTEND;TZID=Europe/Paris:20210401T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1040@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Models of vibronic excitation of a molecule by collision with the electron and attempts to solve them with Krylov space methods
DESCRIPTION:Martin Čížek\n room:Online via Zoom\n I will shortly review our current understanding of electron collisions with molecules with focus on vibrational excitation of molecules and induction of chemical reactions by electrons. Then I will explain the mathematical model of such collisions with reasonable compromise between generality and tractability of the resulting equations. Finally I will discuss our attempts to solve the equations with Krylov space methods. The talk will be presented from a physicist point of view, and I welcome any comments/suggestions from a mathematical perspective in the discussion.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1040
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20201203T140000
DTEND;TZID=Europe/Paris:20201203T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1039@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:An overview of Block Gram-Schmidt methods and their stability properties
DESCRIPTION:Kathryn Lund\n room:Online via Zoom\n Block Gram-Schmidt algorithms comprise essential kernels in many scientific computing applications, but for many commonly used variants, a rigorous treatment of their stability properties remains open. This talk walks through a survey providing a comprehensive categorization of block Gram-Schmidt algorithms, especially those used in Krylov subspace methods to build orthonormal bases one block vector at a time. All known stability results are assembled, and new results are summarized or conjectured for important communication-reducing variants. Additionally, new block versions of low-synchronization variants are derived, and their efficacy and stability are demonstrated for a wide range of challenging examples, including s-step-like matrices. For every method, we numerically confirm known theoretical bounds in plots with varying condition numbers. A MATLAB package for reproducing the results and experimenting with new block Gram-Schmidt methods is hosted at a publicly available repository https://github.com/katlund/BlockStab.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1039
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20201029T140000
DTEND;TZID=Europe/Paris:20201029T153000
LOCATION:Online via Zoom
TRANSP: OPAQUE
SEQUENCE:0
UID:1037@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:High-Performance Mixed Precision Numerical Linear Algebra
DESCRIPTION:Erin Claire Carson\n room:\n Support for floating point arithmetic in multiple precisions is becoming increasingly common in emerging architectures. For example, half precision is now available in the NVIDIA V100 and A100 GPUs, on which it runs twice as fast as single precision with a proportional savings in energy consumption. Further, using the specialized half-precision tensor cores can provide up to 16x speedup over double precision computations. Mixed precision capabilities are already included in many machines on the TOP500 list and are expected to be a crucial hardware feature in coming exascale machines. From a computational scientists perspective, our goal is to determine how and where we can exploit mixed precision computation in our codes. This requires both an understanding of performance characteristics as well as an understanding of the numerical behavior of algorithms in finite precision arithmetic. In this talk, we discuss recent and ongoing efforts in this area. In particular, we present and analyze a general algorithm for solving nxn nonsingular linear systems Ax = b based on iterative refinement in three precisions. From this, we develop GMRES-IR, a three-precision GMRES-based iterative refinement scheme that works for even ill-conditioned systems. We discuss performance results on modern GPU architectures and present the HPL-AI benchmark, based on GMRES-IR, which runs at 445 Petaflops/s in mixed precision on the Summit supercomputer, nearly triple the 148 PFLOP/s that Summit achieved on the standard HPL benchmark used for the TOP500.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1037
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200319T140000
DTEND;TZID=Europe/Paris:20200319T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1034@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1034
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200312T140000
DTEND;TZID=Europe/Paris:20200312T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1033@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:CANCELED !!!! Far-field boundary conditions for incompressible stably stratified flows
DESCRIPTION:Tomáš Bodnár (Czech Technical University)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1033
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200305T140000
DTEND;TZID=Europe/Paris:20200305T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1028@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stochastic Galerkin method
DESCRIPTION:Ivana Pultarová (Czech Technical University)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1028
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200227T140000
DTEND;TZID=Europe/Paris:20200227T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1027@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Radiation hydrodynamics in a moving-mesh code: goals and challenges
DESCRIPTION:Diego Calderon (ITF MFF UK)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1027
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200220T140000
DTEND;TZID=Europe/Paris:20200220T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1025@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Gram-Schmidt in presence of rounding errors
DESCRIPTION:Miroslav Rozložník (IM CAS)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1025
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20200109T140000
DTEND;TZID=Europe/Paris:20200109T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1023@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1023
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191219T140000
DTEND;TZID=Europe/Paris:20191219T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1022@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1022
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191212T140000
DTEND;TZID=Europe/Paris:20191212T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1020@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Positive polynomials and numerical approximation
DESCRIPTION:Bruno Despres (Sorbonne University)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1020
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191205T140000
DTEND;TZID=Europe/Paris:20191205T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1019@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solving the inverse problem of fast moving objects
DESCRIPTION:Filip Šroubek (UTIA AV ČR)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1019
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191128T140000
DTEND;TZID=Europe/Paris:20191128T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1015@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Generalised FEs and Energy Minimisation: Domain Decomposition, Optimal Local Approximation and Local Model Order Reduction
DESCRIPTION:Robert Scheichl (University of Heidelberg)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1015
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191126T104000
DTEND;TZID=Europe/Paris:20191126T121000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1014@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On the zeros of (rational) harmonic functions
DESCRIPTION:Prof. Jörg Liesen  (TU Berlin)\n room:K2\n 29th Colloquium Lecture, School of Mathematics Faculty of Mathematics and Physics
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1014
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191121T140000
DTEND;TZID=Europe/Paris:20191121T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1013@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1013
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191114T140000
DTEND;TZID=Europe/Paris:20191114T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1011@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On convergence behavior of block GMRES and related methods
DESCRIPTION:Marie Kubínová (ÚGN AV ČR)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1011
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191107T140000
DTEND;TZID=Europe/Paris:20191107T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1010@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Adaptive coarse space construction for Domain decomposition methods
DESCRIPTION:Frederic Nataf (Sorbonne University)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1010
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191031T140000
DTEND;TZID=Europe/Paris:20191031T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1008@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Robust adaptive hp discontinuous Galerkin finite element methods for the Helmholtz equation
DESCRIPTION:Scott Congreve (KNM)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1008
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191024T140000
DTEND;TZID=Europe/Paris:20191024T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1006@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Augmented Krylov subspace methods for well- and ill-posed problems
DESCRIPTION:Kirk M. Soodhalter (The University of Dublin)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1006
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191017T140000
DTEND;TZID=Europe/Paris:20191017T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1003@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Goal-oriented a posteriori error estimates and adaptivity for the numerical solution of nonlinear PDEs
DESCRIPTION:Filip Roskovec\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1003
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191010T140000
DTEND;TZID=Europe/Paris:20191010T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1002@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Krylov subspace methods, minimal polynomials and clustering of eigenvalues: intriguing relationships and challenges
DESCRIPTION:Zdeněk Strakoš\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1002
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20191003T140000
DTEND;TZID=Europe/Paris:20191003T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1001@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Just keep walking - Non-backtracking walks in complex networks
DESCRIPTION:Francesca Arrigo (Strathclyde University)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1001
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190523T143000
DTEND;TZID=Europe/Paris:20190523T150000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:1000@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Multilevel methods
DESCRIPTION:Petr Vacek\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/1000
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190523T140000
DTEND;TZID=Europe/Paris:20190523T143000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:999@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Krylov methods for solving linear algebraic problems with matrix observations
DESCRIPTION:Martin Rapavý\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/999
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190516T153000
DTEND;TZID=Europe/Paris:20190516T163000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:998@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A generalized framework for block Krylov subspace methods with restarts, shifts, custom Ritz values, and many applications
DESCRIPTION:Kathryn Lund (EPFL)\n room:Seminar room of Department of Numerical Mathematics\n Abstract: Krylov subspace methods have played an enormous role in numerical linear algebra and scientific computing.  This talk focuses on block Krylov methods and summarizes the attempt to describe as many varieties as possible under a common framework, which is made possible by block inner products and matrix polynomials.  The driving application is the computation of f(A)B, where f is a scalar-valued function, A is a large and sparse matrix, and B is a block vector, or the concatenation of multiple vectors into a tall-and-skinny matrix.  Because it is necessary to store a full basis to compute f(A)B, we only consider methods that allow for restarts.  Moreover, we only consider functions with Cauchy-Stieltjes representations, so that we can take advantage of theory for families of shifted linear systems.  The resulting framework thus accounts for many features at once, including the possibility to customize the Ritz values of the Arnoldi decomposition.  In addition to linear systems, families of shifted linear systems, and univariate matrix functions, we also touch on how this framework can be applied to tensor-valued functions and bivariate functions of matrices.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/998
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190516T140000
DTEND;TZID=Europe/Paris:20190516T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:987@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Alignment models of collective behavior (2nd part)
DESCRIPTION:Roman Shvydkoy\n room:K3\n This is the 2nd part of the series of lectures: L1 Mo May,13 at 9:00 in K2; L2 Th May, 16 at 14:00 in K3; L3 Mo May, 20 at 9:00 in K2 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/987
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190509T140000
DTEND;TZID=Europe/Paris:20190509T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:996@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/996
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190502T140000
DTEND;TZID=Europe/Paris:20190502T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:995@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:How to model a flock of birds
DESCRIPTION:Václav Kučera\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/995
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190425T140000
DTEND;TZID=Europe/Paris:20190425T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:992@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Concepts of Task-based Programming and the PLASMA Numerical Library
DESCRIPTION:Jakub Šístek\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/992
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190418T140000
DTEND;TZID=Europe/Paris:20190418T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:991@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/991
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190411T140000
DTEND;TZID=Europe/Paris:20190411T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:989@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Document understanding and neural networks: line-items and table understanding in structured documents
DESCRIPTION:Martin Holeček\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/989
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190404T140000
DTEND;TZID=Europe/Paris:20190404T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:983@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Optimizing the internal structure of high-performance composite tubes with semidefinite programming
DESCRIPTION:Jan Zeman\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/983
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190328T140000
DTEND;TZID=Europe/Paris:20190328T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:980@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Krylov subspace methods: Connections and Open Questions
DESCRIPTION:Petr Tichý\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/980
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190321T140000
DTEND;TZID=Europe/Paris:20190321T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:985@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On the complexity of the numerical solution of partial differential equations
DESCRIPTION:Vít Dolejší\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/985
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190314T140000
DTEND;TZID=Europe/Paris:20190314T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:978@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite element methods for convection-dominated problems
DESCRIPTION:Petr Knobloch\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/978
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190307T140000
DTEND;TZID=Europe/Paris:20190307T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:981@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Factorization of saddle point matrices in dynamical system optimization-resuing pivots
DESCRIPTION:Jan Kuřátko\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/981
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190228T140000
DTEND;TZID=Europe/Paris:20190228T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:976@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Two-Grid hp-Version Discontinuous Galerkin Finite Element Methods for Strongly Monotone Quasilinear Elliptic PDEs using Agglomerated Coarse Meshes
DESCRIPTION:Scott Congreve\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/976
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190221T140000
DTEND;TZID=Europe/Paris:20190221T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:975@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical solution of traffic flow models
DESCRIPTION:Lukáš Vacek\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/975
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190110T140000
DTEND;TZID=Europe/Paris:20190110T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:973@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Network indexes and matrix functions: Stability and approximation
DESCRIPTION:Pozza Stefano\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/973
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190103T140000
DTEND;TZID=Europe/Paris:20190103T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:972@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/972
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181213T140000
DTEND;TZID=Europe/Paris:20181213T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:966@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/966
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181206T140000
DTEND;TZID=Europe/Paris:20181206T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:959@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Laplacian preconditioning of elliptic operators: localization of the eigenvalues of the discretized problem
DESCRIPTION:Gergelits Tomáš\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/959
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181129T140000
DTEND;TZID=Europe/Paris:20181129T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:965@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Efficient Simulation of Temporal Multiscale Problems
DESCRIPTION:Thomas Richter\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/965
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181122T140000
DTEND;TZID=Europe/Paris:20181122T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:960@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/960
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181115T140000
DTEND;TZID=Europe/Paris:20181115T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:955@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Sparse Numerical Linear Algebra in the Exascale Era
DESCRIPTION:Carson Erin Claire\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/955
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181108T140000
DTEND;TZID=Europe/Paris:20181108T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:950@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On understanding principles and predicting the cost of some numerical computations (2)
DESCRIPTION:Strakoš Zdeněk\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/950
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181101T140000
DTEND;TZID=Europe/Paris:20181101T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:949@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On understanding principles and predicting the cost of some numerical computations (1)
DESCRIPTION:Strakoš Zdeněk\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/949
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181025T140000
DTEND;TZID=Europe/Paris:20181025T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:961@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Seminar is cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/961
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181018T140000
DTEND;TZID=Europe/Paris:20181018T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:952@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Goal-oriented a posteriori error estimates for PDE including algebraic errors (2)
DESCRIPTION:Dolejší Vít\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/952
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181011T140000
DTEND;TZID=Europe/Paris:20181011T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:951@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Goal-oriented a posteriori error estimates for PDE including algebraic errors (1)
DESCRIPTION:Dolejší Vít\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/951
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180517T140000
DTEND;TZID=Europe/Paris:20180517T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:944@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Particulate matter transport and deposition in the ABL with vegetation
DESCRIPTION:Luděk Beneš (FS ČVUT v Praze)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/944
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180510T140000
DTEND;TZID=Europe/Paris:20180510T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:940@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/940
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180503T140000
DTEND;TZID=Europe/Paris:20180503T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:938@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:What we (don’t) know about iteration - a brief introduction to holomorphic dynamics and chaos
DESCRIPTION:Václav Kučera (MFF UK, Praha)\n room:K3\n Abstract: Newton's method is an example of the simple process of iterating a nonlinear mapping on a given space. In the numerical community results on the convergence of Newton's and similar methods are usually local (convergence on a neighborhood of the exact solution). However, in the past hundred years there have been extensive endeavors to answer the question what happens globally. The field of holomorphic dynamics deals with these questions in the complex plane and leads to well known objects in fractal and chaos theory. We give an overview of known results along with some open questions and their relation to Newton's method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/938
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180426T140000
DTEND;TZID=Europe/Paris:20180426T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:937@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/937
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180419T140000
DTEND;TZID=Europe/Paris:20180419T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:922@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Motion of curves with area constraint and applications
DESCRIPTION:Michal Beneš (FJFI ČVUT v Praze)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/922
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180412T140000
DTEND;TZID=Europe/Paris:20180412T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:929@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical simulation of laminar-turbulent transition with RANS approach
DESCRIPTION:Jiří Fürst (FS ČVUT v Praze)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/929
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180405T140000
DTEND;TZID=Europe/Paris:20180405T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:927@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stochastic Galerkin method and its preconditioning
DESCRIPTION:Ivana Pultarová (FSv ČVUT v Praze)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/927
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180329T140000
DTEND;TZID=Europe/Paris:20180329T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:926@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/926
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180323T104000
DTEND;TZID=Europe/Paris:20180323T121000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:923@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Entropy stable high order discontinuous Galerkin methods for hyperbolic conservation laws
DESCRIPTION:Chi-Wang Shu (Brown University)\n room:K1\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/923
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180315T140000
DTEND;TZID=Europe/Paris:20180315T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:921@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Treatment of boundary conditions for conforming mixed finite  elements for the elasticity problems
DESCRIPTION:Ma Rui (Humboldt University, Berlin)\n room:K3\n Abstract: Since conforming symmetric H(div) elements usually involve vertex degrees of freedom, it causes some trouble for discontinuous coefficients, mixed boundary conditions and inconsistent Neumann boundary conditions at the corners and on the edges of the domains. We design a strategy to overcome these difficulties. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/921
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180308T140000
DTEND;TZID=Europe/Paris:20180308T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:920@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Modelling of glottis closure for flow induced vibrations of vocal folds
DESCRIPTION:Petr Sváček (FS ČVUT v Praze)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/920
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180301T140000
DTEND;TZID=Europe/Paris:20180301T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:911@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Noise in Krylov subspace projections for inverse problems
DESCRIPTION:Iveta Hnětynková\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/911
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180222T140000
DTEND;TZID=Europe/Paris:20180222T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:910@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/910
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180111T140000
DTEND;TZID=Europe/Paris:20180111T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:906@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Computer modeling of the inner ear and auditory nerve
DESCRIPTION:Pavel Jungwirth (ÚOCHB AV ČR, Praha)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/906
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20180104T140000
DTEND;TZID=Europe/Paris:20180104T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:905@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On angle conditions in the finite element method
DESCRIPTION:Michal Křížek (MÚ AV ČR, Praha)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/905
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171214T140000
DTEND;TZID=Europe/Paris:20171214T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:901@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Hybridized DG schemes on near optimal meshes
DESCRIPTION:Ajay Mandyam Rangarajan (RWTH Aachen)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/901
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171207T140000
DTEND;TZID=Europe/Paris:20171207T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:898@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Large deformation and contact in fluid-structure interactions
DESCRIPTION:Thomas Richter (University of Magdeburg)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/898
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171130T140000
DTEND;TZID=Europe/Paris:20171130T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:895@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Dilute polymer solutions: theory and simulation
DESCRIPTION:Hana Mizerová & Bangwei She (MÚ AV ČR, Praha)\n room:K3\n Abstract: We propose a kinetic dumbbell-based model for dilute polymer solutions. The unsteady motion of the Newtonian solvent is described by the incompressible Navier-Stokes equations, while the Fokker-Planck equation describes the evolution of the probability density function of polymer molecules. Applying the Peterlin approximation to the nonlinear spring law, we derive a high-dimensional Navier-Stokes-Fokker-Planck system. We also have to deal with a problem of unbounded domain due to the infinite configuration space.  We show the existence of global in time weak solutions to the so-called kinetic Peterlin model and discuss its macroscopic closure. Further, we propose a multiscale scheme that is a combination of a stabilized Lagrange-Galerkin method and a Hermite spectral method. To our best knowledge, this is the first numerical simulation of kinetic models of viscoelastic fluids with infinitely extensible polymers.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/895
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171123T140000
DTEND;TZID=Europe/Paris:20171123T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:896@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/896
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171116T140000
DTEND;TZID=Europe/Paris:20171116T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:894@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:no seminar
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/894
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171109T140000
DTEND;TZID=Europe/Paris:20171109T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:889@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On the discontinuous Galerkin method for the numerical solution of problems with nonlinear Newton boundary conditions
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/889
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171102T140000
DTEND;TZID=Europe/Paris:20171102T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:887@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solving mixed sparse-dense linear least squares by preconditioned iterative methods
DESCRIPTION:Tůma Miroslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/887
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171026T140000
DTEND;TZID=Europe/Paris:20171026T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:883@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/883
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171019T140000
DTEND;TZID=Europe/Paris:20171019T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:876@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solution of some inverse problems for heat and mass transport in unsaturated porous media
DESCRIPTION:Jozef Kačur (Univerzita Komenského v Bratislave)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/876
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171012T140000
DTEND;TZID=Europe/Paris:20171012T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:875@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerics of Markov Chains
DESCRIPTION:Petr Mayer (FSv ČVUT v Praze)\n room:K3\n This seminar is dedicated to the memory of Prof. RNDr. Ivo Marek, DrSc.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/875
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20171005T140000
DTEND;TZID=Europe/Paris:20171005T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:872@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/872
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170914T140000
DTEND;TZID=Europe/Paris:20170914T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:870@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On a constructive local method in nonlinear elasticity
DESCRIPTION:Hans-Peter Gittel (University Leipzig)\n room:KNM\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/870
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170518T140000
DTEND;TZID=Europe/Paris:20170518T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:859@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Gauss quadrature and Lanczos algorithm
DESCRIPTION:Miroslav Pranic (MFF UK)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/859
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170511T140000
DTEND;TZID=Europe/Paris:20170511T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:869@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Krylov subspace methods from the historical, analytic, application, and high performance computing perspective
DESCRIPTION:Strakoš Zdeněk\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/869
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170504T140000
DTEND;TZID=Europe/Paris:20170504T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:864@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Applied mathematics research at exascale
DESCRIPTION:Esmond G. Ng (Berkeley Lab)\n room:K3\n A lecture organized in cooperation with the Mathematical Institute of the Czech Academy of Sciences.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/864
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170427T140000
DTEND;TZID=Europe/Paris:20170427T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:860@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Mathematical model of induction heating
DESCRIPTION:Josef Rak (Univerzita Pardubice)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/860
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170420T140000
DTEND;TZID=Europe/Paris:20170420T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:865@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Exponential growth, exponential scaling, and DG
DESCRIPTION:Kučera Václav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/865
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170413T150000
DTEND;TZID=Europe/Paris:20170413T163000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:854@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/854
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170406T140000
DTEND;TZID=Europe/Paris:20170406T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:853@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Lower bounds on eigenvalues of symmetric elliptic operators
DESCRIPTION:Tomáš Vejchodský (MÚ AV ČR)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/853
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170330T140000
DTEND;TZID=Europe/Paris:20170330T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:856@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerical simulations of flow induced vocal folds vibrations with stabilized finite element method
DESCRIPTION:Petr Sváček (FS ČVUT, Praha)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/856
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170323T140000
DTEND;TZID=Europe/Paris:20170323T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:858@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/858
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170316T140000
DTEND;TZID=Europe/Paris:20170316T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:851@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Analysis of a group finite element formulation
DESCRIPTION:Knobloch Petr\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/851
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170309T140000
DTEND;TZID=Europe/Paris:20170309T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:849@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:An anisotropic hp-adaptive method based on continuous mesh and error models
DESCRIPTION:Dolejší Vít\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/849
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170302T140000
DTEND;TZID=Europe/Paris:20170302T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:848@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Analysis of the DG method applied to an elliptic problem with nonlinear Newton boundary condition
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/848
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170223T140000
DTEND;TZID=Europe/Paris:20170223T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:846@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Operator preconditioning for saddle point systems: trace constrained and singular PDEs
DESCRIPTION:Miro Kuchta (University of Oslo)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/846
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170112T140000
DTEND;TZID=Europe/Paris:20170112T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:843@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/843
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170105T140000
DTEND;TZID=Europe/Paris:20170105T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:840@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stokes system with threshold slip boundary conditions: existence and uniqueness analysis, numerical solution
DESCRIPTION:Haslinger Jaroslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/840
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161222T140000
DTEND;TZID=Europe/Paris:20161222T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:838@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/838
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161215T140000
DTEND;TZID=Europe/Paris:20161215T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:837@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/837
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161208T140000
DTEND;TZID=Europe/Paris:20161208T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:836@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Discontinuous Galerkin method for the solution of elasto-dynamic and fluid-structure interaction problems
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/836
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161201T140000
DTEND;TZID=Europe/Paris:20161201T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:835@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A posteriori error estimates for parabolic problems
DESCRIPTION:Vlasák Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/835
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161124T140000
DTEND;TZID=Europe/Paris:20161124T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:832@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Variationally-based quasi-continuum methods for discrete dissipative systems
DESCRIPTION:Jan Zeman (FSv ČVUT)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/832
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161110T140000
DTEND;TZID=Europe/Paris:20161110T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:831@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On the pedestrian flow problem
DESCRIPTION:Felcman Jiří\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/831
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161103T140000
DTEND;TZID=Europe/Paris:20161103T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:828@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solvability of TLS problems: results and open questions
DESCRIPTION:Hnětynková Iveta\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/828
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161027T140000
DTEND;TZID=Europe/Paris:20161027T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:826@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/826
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161020T140000
DTEND;TZID=Europe/Paris:20161020T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:825@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On solving linear systems arising from Shishkin mesh discretizations
DESCRIPTION:Tichý Petr\n room:K3\n Abstract: We consider a convection-diffusion boundary value problem (1D, convection dominated) with Dirichlet boundary conditions. Because of the occurrence of boundary layers in the solution, such problems are difficult to solve numerically. Standard discretization techniques typically cannot resolve the layers and have to be stabilized in order to yield an acceptable numerical solution. Here we consider discretizations using a Shishkin mesh, which clusters mesh points in the layer instead of putting them equidistantly over the whole region, leading to linear algebraic systems with highly nonnormal matrices. In this talk we are interested in solving such systems using the GMRES method and the multiplicative Schwarz method.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/825
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161013T140000
DTEND;TZID=Europe/Paris:20161013T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:821@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Entropy stable spacetime discontinuous Galerkin methods for the compressible Navier-Stokes equations
DESCRIPTION:Sandra May (TU Dortmund)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/821
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20161006T140000
DTEND;TZID=Europe/Paris:20161006T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:820@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Asymptotic preserving schemes for singular limit flows
DESCRIPTION:Mária Lukáčová (Universität Mainz)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/820
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160915T140000
DTEND;TZID=Europe/Paris:20160915T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:819@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Young measure solutions and companion conservation laws for transonic potential flow
DESCRIPTION:Hans-Peter Gittel (Universität Leipzig)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/819
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160526T140000
DTEND;TZID=Europe/Paris:20160526T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:818@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/818
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160519T140000
DTEND;TZID=Europe/Paris:20160519T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:817@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/817
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160512T140000
DTEND;TZID=Europe/Paris:20160512T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:816@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Math goes public: interesting phenomena in nonlinear problems
DESCRIPTION:Klaus Boehmer, University Marburg\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/816
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160505T140000
DTEND;TZID=Europe/Paris:20160505T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:811@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Generalized Jacobi matrices: definition, properties, relations
DESCRIPTION:Hnětynková Iveta\n room:K3\n Abstract: Jacobi matrices, i.e. symmetric tridiagonal matrices with positive subdiagonal entries, represent thoroughly studied objects connected to various mathematical problems. In this presentation, we introduce and study wedge-shaped matrices that can be viewed as a generalization of Jacobi matrices. The definition is motivated by the structure of output matrices in band generalizations of particular Krylov subspace methods.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/811
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160428T140000
DTEND;TZID=Europe/Paris:20160428T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:812@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Svorníkový prvek v metodě konečných prvků
DESCRIPTION:David Runt (FSv ČVUT)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/812
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160421T140000
DTEND;TZID=Europe/Paris:20160421T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:809@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/809
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160414T140000
DTEND;TZID=Europe/Paris:20160414T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:808@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stable and accurate difference methods for wave propagation
DESCRIPTION:Anna Nissen (University of Bergen)\n room:K3\n Abstract: High-order and stable discretizations are essential for many applications involving wave propagation, such as earthquake rupture dynamics and numerical quantum dynamics. Imposing boundary conditions for high-order finite difference methods in a numerically stable way can be challenging, and the accuracy order of the numerical stencil is typically reduced close to boundaries in favor of stability. Energy estimates can be used to show time-stability for spatial discretizations, but the accuracy estimates that follow are not always sharp. Normal mode analysis on the other hand provides a general accuracy analysis framework that lead to sharp estimates, although working out the details may be challenging. In this talk I will discuss how energy estimates and normal mode analysis can be combined to obtain estimates for stability and accuracy for finite difference discretizations of wave propagation problems.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/808
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160407T140000
DTEND;TZID=Europe/Paris:20160407T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:807@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A stabilized FE-FV scheme for the Navier-Stokes-Fourier system
DESCRIPTION:Bangwei She (MÚ AV ČR, Praha)\n room:K3\n Abstract: We study a mixed finite element-finite volume method for the system describing the motion of a compressible, heat conducting viscous fluid. We show that the scheme is unconditional stable and positivity  preserving. (The convergence of the scheme to a suitable weak solution is also possible.)
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/807
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160324T140000
DTEND;TZID=Europe/Paris:20160324T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:803@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:An optimal Q-OR Krylov method for solving linear systems
DESCRIPTION:Gerard Meurant (Paris)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/803
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160317T140000
DTEND;TZID=Europe/Paris:20160317T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:802@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/802
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160310T140000
DTEND;TZID=Europe/Paris:20160310T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:801@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/801
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160303T140000
DTEND;TZID=Europe/Paris:20160303T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:798@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Discontinuous Galerkin method for an elliptic problem with nonlinear newton boundary conditions
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/798
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160225T140000
DTEND;TZID=Europe/Paris:20160225T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:797@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/797
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160114T140000
DTEND;TZID=Europe/Paris:20160114T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:792@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Residual based error estimates and adaptations of the space-time discontinuous Galerkin method applied to nonlinear hyperbolic equations
DESCRIPTION:Dolejší Vít\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/792
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20160107T140000
DTEND;TZID=Europe/Paris:20160107T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:791@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Finite element - discontinuous Galerkin method for the numerical simulation of two-phase flow
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/791
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151217T140000
DTEND;TZID=Europe/Paris:20151217T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:784@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Preconditioned iterative methods for solving indefinite linear systems
DESCRIPTION:Tůma Miroslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/784
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151210T140000
DTEND;TZID=Europe/Paris:20151210T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:786@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Axioms of adaptivity
DESCRIPTION:Carsten Carstensen (Humboldt-Universität Berlin)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/786
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151203T140000
DTEND;TZID=Europe/Paris:20151203T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:785@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Solution of large engineering problems on parallel computers
DESCRIPTION:Jaroslav Kruis (FSv ČVUT, Praha)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/785
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151126T140000
DTEND;TZID=Europe/Paris:20151126T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:783@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/783
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151119T140000
DTEND;TZID=Europe/Paris:20151119T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:781@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/781
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151112T130000
DTEND;TZID=Europe/Paris:20151112T143000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:774@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Relative energy methods for models of compressible multi-phase flows
DESCRIPTION:Jan Giesselmann (Universität Stuttgart)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/774
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151105T140000
DTEND;TZID=Europe/Paris:20151105T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:777@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Stability analysis of the space-time discontinuous Galerkin method for a nonlinear convection-diffusion problem in time dependent domains
DESCRIPTION:Balázsová Monika\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/777
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151029T130000
DTEND;TZID=Europe/Paris:20151029T143000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:772@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/772
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151022T140000
DTEND;TZID=Europe/Paris:20151022T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:771@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:On linearity preservation and discrete maximum principle for algebraic flux correction schemes
DESCRIPTION:Knobloch Petr\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/771
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151015T140000
DTEND;TZID=Europe/Paris:20151015T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:769@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Regularity results for parabolic problems in polygons
DESCRIPTION:Anna-Margarete Sändig (Universität Stuttgart)\n room:K3\n This lecture is the 18th lecture of the Mathematical Colloquium organized by the School of Mathematics of the Faculty of Mathematics and Physics.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/769
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20151008T140000
DTEND;TZID=Europe/Paris:20151008T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:767@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Goal-oriented adaptivity and optimization for fluid-structure interactions
DESCRIPTION:Thomas Richter (Universität Erlangen-Nürnberg)\n room:K3\n In this talk, we present a sensitivity based framework for adaptive finite element simulations and optimization of fluid-structure interactions. The talk will be split into three parts. First, we will introduce basic concepts of sensitivity analysis for error estimation, mesh adaptivity and gradient based optimization tools. The focus will be on easy and efficient applicability for such complex problems as fluid-structure interactions. In particular, a residual based error estimator will be presented, that does not require jump-terms or evaluation of strong operators involving second derivatives. This will be a substantial improvement over standard estimators. Second, we will derive dual formulations for fluid-structure interactions. With the help of linearized adjoint problems, we will be able to compute sensitivities with respect to technical goal values, such as drag- or lift-coefficients, stress measures or flow rates. Finally, we will use these adjoint solutions to derive reliable error estimates controlling mesh adaptivity and to guide simple gradient based optimization schemes. 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/767
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150924T143000
DTEND;TZID=Europe/Paris:20150924T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:766@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Contour dynamics in a diphasic low Mach number flow
DESCRIPTION:Hans-Peter Gittel\n room:K3\n Universität Leipzig
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/766
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150521T140000
DTEND;TZID=Europe/Paris:20150521T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:593@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/593
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150514T140000
DTEND;TZID=Europe/Paris:20150514T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:594@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:A comparative study on iterative solvers for FFT-based homogenization of periodic media
DESCRIPTION:Nachiketa Mishra (FSv ČVUT, Praha)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/594
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150507T140000
DTEND;TZID=Europe/Paris:20150507T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:597@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/597
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150430T140000
DTEND;TZID=Europe/Paris:20150430T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:588@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/588
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150423T140000
DTEND;TZID=Europe/Paris:20150423T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:587@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Sparse Gaussian elimination: myths and facts
DESCRIPTION:Esmond G. Ng (Lawrence Berkeley National Laboratory)\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/587
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150416T140000
DTEND;TZID=Europe/Paris:20150416T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:596@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/596
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150409T140000
DTEND;TZID=Europe/Paris:20150409T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:595@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:cancelled
DESCRIPTION:\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/595
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150402T140000
DTEND;TZID=Europe/Paris:20150402T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:548@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Numerická simulace vibrací leteckého profilu indukovaných turbulentním prouděním
DESCRIPTION:Feistauer Miloslav\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/548
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150326T140000
DTEND;TZID=Europe/Paris:20150326T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:407@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Model of transverse vibrations in elastic-plastic beams and boards
DESCRIPTION:Pavel Krejčí\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/407
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150319T140000
DTEND;TZID=Europe/Paris:20150319T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:406@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Multiphase and phase transition flows, 2nd part: Sharp-interface models
DESCRIPTION:Christian Rohde\n room:K3\n 
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/406
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150312T140000
DTEND;TZID=Europe/Paris:20150312T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:390@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:Cosmological perturbation theory for mathematicians
DESCRIPTION:Jan Novák\n room:K3\n We will introduce basic principles of cosmology in my talk. We will study, so called f(R)-cosmologies, as a promising way, how to model accelerated expansion of the Universe. We want to apply our result from cosmological perturbation theory to numerical simulation of motion of dwarf galaxy in gravitational potential.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/390
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20150305T140000
DTEND;TZID=Europe/Paris:20150305T153000
LOCATION:Sokolovská 83, Praha
TRANSP: OPAQUE
SEQUENCE:0
UID:389@knm.mff.cuni.cz
DTSTAMP:20260413T151134
SUMMARY:The discontinuous Galerkin method in ocean simulation
DESCRIPTION:Vadym Aizinger\n room:K3\n Trying to close the performance gap: the discontinuous Galerkin method in ocean simulation.
PRIORITY:1
CLASS:PUBLIC
URL:http://knm.karlin.mff.cuni.cz/events/event/389
END:VEVENT
END:VCALENDAR