Články / Articles (NTIS) Collection home page

Subscribe to this collection to receive daily e-mail notification of new additions RSS Feed RSS Feed RSS Feed
Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 154
Bobkov, Vladimír , Kolonitskii, Sergey
On a property of the nodal set of least energy sign-changing solutions for quasilinear elliptic equations

In this note, we prove the Payne-type conjecture about the behaviour of the nodal set of least energy sign-changing solutions for the equation -Delta(p)u = f(u) in bounded Steiner symmetric domains Omega subset of R-N under the zero Dirichlet boundary conditions. The nonlinearity f...

Bobkov, Vladimír , Tanaka, Mieko
On the Fredholm-type theorems and sign properties of solutions for (p,q)-Laplace equations with two parameters

We consider the Dirichlet problem for the nonhomogeneous equation -Delta pu-Delta qu=alpha |u|p-2u+beta |u|q-2u+f(x) in a bounded domain, where p not equal q, and alpha,beta is an element of R are parameters. We explore assumptions on alpha and beta that guarantee the resolvability ...

Bobkov, Vladimír , Drábek, Pavel , Ilyasov, Yavdat
On full Zakharov equation and its approximations

We study the solvability of the Zakharov equation in a bounded domain under homogeneous Dirichlet or Navier boundary conditions. This problem is a consequence of the system of equations derived by Zakharov to model the Langmuir collapse in plasma physics. Assumptions for the existe...

Novák, Pavel , Pitoňák, Martin , Šprlák, Michal , Tenzer, Robert
Higher-order gravitational potential gradients for geoscientific applications

Gravity data have been applied for modelling and interpretation studies in geosciences. This contribution reviews currently observable and foreseen gravity data represented by gradients of the gravitational potential. Functional models linking 3-D mass density distribution functions to potential gradients&...

Goli, Mehdi , Foroughi, Ismael , Novák, Pavel
Application of the one-step integration method for determination of the regional gravimetric geoid

The regional gravimetric geoid solved using boundary-value problems of the potential theory is usually determined in two computational steps: (1) downward continuing ground gravity data onto the geoid using inverse Poisson’s integral equation in a mass-free space and (2) evaluating geoidal h...

Jiřinec, Jakub , Rot, David , Šenkýř, Vojtěch
Measurement of indoor environment parameters in a classroom equipped with heat recovery unit

We demonstrate several ways to use morphological word analogies to examine the representation of complex words in semantic vector spaces. We present a set of morphological relations, each of which can be used to generate many word analogies. 1. We show that the difference-vectors&#...

Gabriel, František , Kursová, Lucie
Typové zařazení hradu Skála u Přeštic

Background: Protected health information burned in pixel data is not indicated for various reasons in DICOM. It complicates the secondary use of such data. In recent years, there have been several attempts to anonymize or de-identify DICOM files. Existing approaches have different const...

Hromádka, Aleš , Jiřičková, Jana , Martínek, Zbyněk , Sirový, Martin
Operation assessment of cogeneration power plant by thermodynamic model

SfePy (simple finite elements in Python) is a software for solving various kinds of problems described by partial differential equations in one, two, or three spatial dimensions by the finite element method. Its source code is mostly (85%) Python and relies on fast vectorized ...

Včelák, Petr , Kryl, Martin , Kratochvíl, Michal , Klečková, Jana
Identification and classification of DICOM files with burned-in text content

The ability to represent the meaning of words is one of the core parts of natural language understanding (NLU), with applications ranging across machine translation, summarization, question answering, information retrieval, etc. The need for reasoning in multilingual contexts and transferring kno...

Hromádková, Věra , Kolingerová, Ivana , Vaněček, Petr
A unified curvature-driven approach for weathering and hydraulic erosion simulation on triangular meshes

The significant properties of the maximum likelihood (ML) estimate are consistency, normality, and efficiency. While it has been proven that these properties are valid when the sample size approaches infinity, the behavior of an ML estimator when working with small sample sizes is ...

Martínek, Jiří , Lenc, Ladislav , Král, Pavel
Training Strategies for OCR Systems for Historical Documents

Random Sample Consensus is a powerful paradigm that was successfully applied in various contexts, including Location Determination Problem, fundamental matrix estimation and global 3D surface registration, where many previously proposed algorithms can be interpreted as a particular implementation of t...

Hložek, Josef , Profantová, Naďa , Menšík, Petr
Železná jehlice z hradiště Kněží hora u Katovic (okres Strakonice) a obtížně datovatelné nálezy jehlic z výšinných sídlišť v širších souvislostech

The paper deals with modelling of acoustic waves which propagate in inviscid fluids interacting with perforated elastic plates. The plate can be replaced by an interface on which transmission conditions are derived by homogenization of a problem describing vibroacoustic fluid-structure interactio...

Cooper, Jacob W. , Kaiser, Tomáš , Král', Daniel , Noel, Jonathan A.
Weak regularity and finitely forcible graph limits

Graphons are analytic objects representing limits of convergent sequences of graphs. Lovász and Szegedy conjectured that every finitely forcible graphon, i.e. any graphon determined by finitely many subgraph densities, has a simple structure. In particular, one of their conjectures would imply&#x...

Hoffmann-Ostenhof, Arthur , Kaiser, Tomáš , Ozeki, Kenta
Decomposing planar cubic graphs

The 3‐Decomposition Conjecture states that every connected cubic graph can be decomposed into a spanning tree, a 2‐regular subgraph and a matching. We show that this conjecture holds for the class of connected plane cubic graphs.

Basić, Nino , Estélyi, István , Škrekovski, Riste , Tratnik, Niko
On the Clar Number of Benzenoid Graphs

A Clar set of a benzenoid graph B is a maximum set of independent alternating hexagons over all perfect matchings of B. The Clar number of B, denoted by Cl(B), is the number of hexagons in a Clar set for B. In this paper, we first prove some results on...

Chlebicka, Iwona , Drábek, Pavel , Kalamajska, Agnieszka
Caccioppoli-type estimates and Hardy-type inequalities derived from weighted p-harmonic problems

We obtain Caccioppoli-type estimates for nontrivial and nonnegative solutions to anticoercive partial differential inequalities of elliptic type involving weighted p-Laplacian. Using Caccioppoli-type estimates, we obtain several variants of Hardy-type inequalities in weighted Sobolev spaces.

Bizzarri, Michal , Lávička, Miroslav , Vršek, Jan
Linear computational approach to interpolations with polynomial Minkowski Pythagorean hodograph curves

Methods using Pythagorean hodographs both in Euclidean plane and Minkowski space are often used in geometric modelling when necessary to solve the problem of rationality of offsets of planar domains. A main justification for studying and formulating approximation and interpolation algorithms ...

Bobkov, Vladimír , Drábek, Pavel , Ilyasov, Yavdat
On partially free boundary solutions for elliptic problems with non-lipschitz nonlinearities

We show that the elliptic equation with non-Lipschitz right-hand side, considered on a smooth star-shaped domain Ω subject to zero Dirichlet boundary conditions, might possess a nonnegative ground state solution which violates Hopf’s maximum principle only on a nonempty subset Γ of the&...

Hynčík, Luděk , Bońkowski, Tomasz
Helmet to head coupling by multi-body system

Bobkov, Vladimír
Asymptotic relation for zeros of cross-product of Bessel functions and applications

Let $a_{\nu,k}$ be the $k$-th positive zero of the cross-product of Bessel functions $J_\nu(R z) Y_\nu(z) - J_\nu(z) Y_\nu(R z)$, where $\nu\geq 0$ and $R>1$. We derive an initial value problem for a first order differential equation whose solution $\alpha(x)...

Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 154