Prohlížení Acta Polytechnica dle názvu
Zobrazují se záznamy 550-569 z 880
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OBLIQUE MAGNETIC FIELDS AND THE ROLE OF FRAME DRAGGING NEAR ROTATING BLACK HOLE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)Magnetic null points can develop near the ergosphere boundary of a rotating black hole by the combined effects of strong gravitational field and the frame-dragging mechanism. The induced electric component does not vanish ... -
On a static and dynamic calibration of thermochromic liquid crystals
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2021)The paper deals with a static and dynamic calibration of selected wide-range thermochromic liquid crystals (TLC - SolarDust 24C), which are very easy to ingest and can provide accurate information on the temperature ... -
On an Algorithm for Multiperiodic Words
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)We consider an algorithm by Tijdeman and Zamboni constructing a word of length k thathas periods p1, . . . , pr, and the richest possible alphabet. We show that this algorithm can be easilystated and its correctness briefly ... -
ON CFD INVESTIGATION OF RADIAL CLEARANCE OF LABYRINTH SEALS OF A TURBINE ENGINE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Fluid flow in labyrinth seals of a turbine engine is described. The aim is to describe numerical calculations of fluid flow in labyrinth seals and evaluate the calculated data for different settings of radial clearance of ... -
ON CONNECTING WEYL-ORBIT FUNCTIONS TO JACOBI POLYNOMIALS AND MULTIVARIATE (ANTI)SYMMETRIC TRIGONOMETRIC FUNCTIONS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)The aim of this paper is to make an explicit link between the Weyl-orbit functions and the corresponding polynomials, on the one hand, and to several other families of special functions and orthogonal polynomials on the ... -
ON CUBATURE RULES ASSOCIATED TO WEYL GROUP ORBIT FUNCTIONS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)The aim of this article is to describe several cubature formulas related to the Weyl group orbit functions, i.e. to the special cases of the Jacobi polynomials associated to root systems. The diagram containing the relations ... -
ON GENERALIZATION OF SPECIAL FUNCTIONS RELATED TO WEYL GROUPS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)Weyl group orbit functions are defined in the context of Weyl groups of simple Lie algebras. They are multivariable complex functions possessing remarkable properties such as (anti)invariance with respect to the corresponding ... -
On generalized Heun equation with some mathematical properties
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2022)We study the analytic solutions of the generalized Heun equation, (α0 + α1 r + α2 r2 + α3 r3) y′′ + (β0 + β1 r + β2 r2) y′ + (ε0 + ε1 r) y = 0, where |α3| + |β2|≠ 0, and {αi}3i=0, {βi}2i=0, {εi}1i=0 are real parameters. ... -
ON IMMERSION FORMULAS FOR SOLITON SURFACES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)This paper is devoted to a study of the connections between three different analytic descriptions for the immersion functions of 2D-surfaces corresponding to the following three types of symmetries: gauge symmetries of the ... -
ON OBSERVATIONAL PHENOMENA RELATED TO KERR SUPERSPINARS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)We investigate possible signatures of a Kerr naked singularity (superspinar) in various observational phenomena. It has been shown that Kerr naked singularities (superspinars) have to be efficiently converted to a black ... -
ON PARTIAL DIFFERENTIAL AND DIFFERENCE EQUATIONS WITH SYMMETRIES DEPENDING ON ARBITRARY FUNCTIONS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)In this note we present some ideas on when Lie symmetries, both point and generalized, can depend on arbitrary functions. We show a few examples, both in partial differential and partial difference equations where this ... -
On reducing CO2 concentration in buildings by using plants
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2021)The article deals with the implementation of plants in the indoor environment of buildings to reduce the concentration of CO2. Based on a specified model representing the internal environment of an office space, it was ... -
ON RENORMALIZATION OF POISSON–LIE T-PLURAL SIGMA MODELS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)Covariance of the one-loop renormalization group equations with respect to Poisson–Lie T-plurality of sigma models is discussed. The role of ambiguities in renormalization group equations of Poisson–Lie sigma models with ... -
ON SELF-SIMILARITIES OF CUT-AND-PROJECT SETS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)Among the commonly used mathematical models of quasicrystals are Delone sets constructed using a cut-and-project scheme, the so-called cut-and-project sets. A cut-and-project scheme (L,π1, π2) is given by a lattice L in Rs ... -
On some algebraic formulations within universal enveloping algebras related to superintegrability
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2022)We report on some recent purely algebraic approaches to superintegrable systems from the perspective of subspaces of commuting polynomials in the enveloping algebras of Lie algebras that generate quadratic (and eventually ... -
On Some Statistical Properties of GRBs with Measured Redshifts Having Peaks in Optical Light Curves
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)We studied the subset of optical light curves of gamma-ray bursts with measured redshifts and well-sampled R band data that have clearly detected peaks. Among 43 such events, 11 are promptoptical peaks (P), coincident with ... -
ON THE COMMON LIMIT OF THE PT-SYMMETRIC ROSEN–MORSE II AND FINITE SQUARE WELL POTENTIALS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)Two PT-symmetric potentials are compared, which possess asymptotically finite imaginary components: the PT-symmetric Rosen-Morse II and the finite PT-symmetric square well potentials. Despite their different mathematical ... -
ON THE CONSTRUCTION OF PARTIAL DIFFERENCE SCHEMES II: DISCRETE VARIABLES AND SCHWARZIAN LATTICES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)In the process of constructing invariant difference schemes which approximate partial differential equations we write down a procedure for discretizing a partial differential equation on an arbitrary lattice. An open problem ... -
ON THE REAL MATRIX REPRESENTATION OF PT-SYMMETRIC OPERATORS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)We discuss the construction of real matrix representations of PT-symmetric operators. We show the limitation of a general recipe presented some time ago for non-Hermitian Hamiltonians with antiunitary symmetry and propose ... -
On the Relation Between GRB Classes and Xray Flashes
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2012)Gamma-ray bursts are usually classified into either short-duration or long-duration bursts. Going beyond the short-long classification scheme, it has been shown on statistical grounds that a third, intermediate population ...