Horníková, Hana
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Vuik, Cornelis
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Egermaier, Jiří
A comparison of block preconditioners for isogeometric analysis discretizations of the incompressible Navier-Stokes equations We deal with numerical solution of the incompressible Navier-Stokes equations discretized using the isogeometric analysis (IgA) approach. Similarly to finite elements, the discretization leads to sparse nonsymmetric saddle-point linear systems. The IgA discretization basis has several specific properties d... |
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Bizzarri, Michal
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Lávička, Miroslav
Interpolation of Hermite data by clamped Minkowski Pythagorean hodograph B-spline curves Amorphous HfMSiBCN materials (M = Y, Ho, Ta, Mo or an enhanced Hf content instead of any other M) are investigated by ab initio calculations and magnetron sputtering. We focus on combining the high-temperature stability and oxidation resistance of these materials with optimised mec... |
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Bizzarri, Michal
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Lávička, Miroslav
Construction of Minkowski Pythagorean hodograph B-spline curves Following and extending the recent results of Albrecht et all. (2017) for planar Pythagorean hodograph (PH) B-spline curves to the Minkowski 3-space, we introduce a class of Minkowski Pythagorean hodograph (MPH) B-spline curves. The distinguished property of these curves is that the Min... |
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Bizzarri, Michal
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Lávička, Miroslav
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Vršek, Jan
Note on determining approximate symmetries of planar algebraic curves with inexact coefficients This paper$^{*}$ is devoted to a certain modification of the recently published method for an approximate reconstruction of inexact planar curves which are assumed to be perturbations of some unknown planar symmetric curves. The input curve is given by a perturbed polynomial and th... |
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Bizzarri, Michal
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Lávička, Miroslav
,
Vršek, Jan
Approximate symmetries of planar algebraic curves with inexact input |
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Bizzarri, Michal
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Lávička, Miroslav
,
Vršek, Jan
Computing projective equivalences of special algebraic varieties This paper is devoted to the investigation of selected situations when computing projective (and other) equivalences of algebraic varieties can be efficiently solved via finding projective equivalences of finite sets of points on the projective line. In particular, we design a method th... |
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Pospíšil, Jan
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Sobotka, Tomáš
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Ziegler, Philippe
Robustness and sensitivity analyses for stochastic volatility models under uncertain data structure In this paper, we perform robustness and sensitivity analysis of several continuous-time stochastic volatility (SV) models with respect to the process of market calibration. The analyses should validate the hypothesis on importance of the jump part in the underlying model dynamics. Also ... |
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Alcazar, Juan Gerardo
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Lávička, Miroslav
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Vršek, Jan
Symmetries and similarities of planar algebraic curves using harmonic polynomials We present novel, deterministic, efficient algorithms to compute the symmetries of a planar algebraic curve, implicitly defined, and to check whether or not two given implicit planar algebraic curves are similar, i.e. equal up to a similarity transformation. Both algorithms are based on... |
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Aharoni, Ron
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Kaiser, Tomáš
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Zerbib, Shira
Fractional covers and matchings in families of weighted d-intervals A d-interval is a union of at most d disjoint closed intervals on a fixed line. Tardos [Combinatorica 15 (1995), 123-134] and the second author [Disc. Comput. Geom. 18 (1997), 195-203] used topological tools to bound the transversal number τ of a family H of d-intervals&#... |
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Gajarský, Jakub
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Hliněný, Petr
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Kaiser, Tomáš
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Král', Daniel
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Kupec, Martin
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Obdržálek, Jan
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Ordyniak, Sebastian
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Tůma, Vojtěch
First order limits of sparse graphs: Plane trees and path-width Nešetřil and Ossona de Mendez introduced the notion of first order convergence as an attempt to unify the notions of convergence for sparse and dense graphs. It is known that there exist first order convergent sequences of graphs with no limit modeling (an analytic representat... |
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Chhetri, Maya
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Girg, Petr
Globální bifurkace pro jistou třídu soustav eliptických PDR s nelinearitou typu "semipoziton" We study a class of semipositone elliptic systems depending on a parameter using bifurcation theory. We show that there are two disjoint unbounded connected components of the solution set and discuss the nodal properties of solutions on these components. Finally, as a consequence o... |
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Vršek, Jan
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Lávička, Miroslav
Translation surfaces and isotropic nets on rational minimal surfaces We will deal with the translation surfaces which are the shapes generated by translating one curve along another one. We focus on the geometry of translation surfaces generated by two algebraic curves in space and study their properties, especially those useful for geometric modell... |
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Friesl, Michal
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Lenten, Liam J.A.
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Libich, Jan
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Stehlík, Petr
Zvyšování atraktivity ledního hokeje změnou pořadí střídání stran The popularity and business impact of major sports have been growing globally over time. This paper focuses on ice hockey, specifically the National Hockey League in North America. It reports a striking irregularity in ice hockey’s scoring dynamics relative to comparable sports such... |
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Bizzarri, Michal
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Lávička, Miroslav
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Vršek, Jan
Piecewise rational approximation of square-root parameterizable curves using the Weierstrass form In this paper we study situations when non-rational parameterizations of planar or space curves as results of certain geometric operations or constructions are obtained, in general. We focus especially on such cases in which one can identify a rational mapping which is a double... |
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Stehlík, Petr
Expoinenciální počet řešení Nagumovy rovnice na grafech We study the Nagumo reaction–diffusion equation on graphs and its dependence on the underlying graph structure and reaction–diffusion parameters. We provide necessary and sufficient conditions for the existence and nonexistence of spatially heterogeneous stationary solutions. Furthermore, we observe that&#... |
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Bizzarri, Michal
,
Lávička, Miroslav
Rational adaptive blends among obstacles in 3D by contour method In this paper we will continue in investigating ‘contour method’ and its using for the computation of rational parameterizations of canal surfaces without a need of sum of squares (SOS) decomposition. Further approaches for constructing flexible smooth transitions between canal surfaces will... |
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Bizzarri, Michal
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Lávička, Miroslav
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Kosinka, Jiří
Skinning and blending with rational envelope surfaces We continue the study of rational envelope (RE) surfaces. Although these surfaces are parametrized with the help of square roots, when considering an RE patch as the medial surface transform in 4D of a spatial domain it yields a rational parametrization of the domain’s boundar... |
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Bizzarri, Michal
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Lávička, Miroslav
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Šír, Zbyněk
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Vršek, Jan
Hermite interpolation by piecewise polynomial surfaces with polynomial area element This paper is devoted to the construction of polynomial 2-surfaces which possess a polynomial area element. In particular we study these surfaces in the Euclidean space R^3 (where they are equivalent to the PN surfaces) and in the Minkowski space R^{3,1} (where they provide th... |
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Pospíšil, Jan
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Sobotka, Tomáš
Tržní kalibrace pro model stochastické volatility s dlouhou pamětí In this article, we study a long memory stochastic volatility model (LSV), under which stock prices follow a jump-diffusion stochastic process and its stochastic volatility is driven by a continuous-time fractional process that attains a long memory. LSV model should take into account&#... |
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Collection's Items (Sorted by Submit Date in Descending order): 1 to 19 of 19
Collection's Items (Sorted by Submit Date in Descending order): 1 to 19 of 19