National Repository of Grey Literature 198 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Mathematical modeling of vibrational dynamics in electron scattering from molecule.
Šarmanová, Martina ; Čížek, Martin (advisor) ; Pultarová, Ivana (referee)
In this work, we study low-energy electron-molecule collisions. To understand these processes, it is necessary to explain the phenomena appearing in so called 2D electron energy-loss spectra. These spectra are very different for different molecules, which we still cannot explain satisfactorily. Therefore we would like to gain deeper understand- ing through mathematical modeling of the problem. The collision of an electron with a molecule can be mathematically formulated in the language of partial integro-differential equations. The discretization converts the problem to a system of linear algebraic equa- tions with a complex symmetric matrix. The matrix of this system is also sparse and for this reason we believe that the use of iterative methods to solve the resulting system is a suitable choice. However, as we were convinced when testing the convergence rate of the Krylov subspace methods for the model with two degrees of freedom (which we dealt with in the bachelor thesis), iterative methods suffer from slow convergence. This motivated us to try using preconditioning which is considered to be crucial for the relia- bility of iterative techniques across the literature. Our main goal in this work was to find a suitable preconditioning technique for Krylov subspace methods, which would ensure their faster...
Fragmentation-free ultrastable transfers through shared optical fibers
Vojtěch, J. ; Smotlacha, V. ; Havliš, O. ; Šlapák, M. ; Altmannová, L. ; Kundrát, J. ; Vohnout, R. ; Velc, R. ; Čížek, Martin ; Hrabina, Jan ; Řeřucha, Šimon ; Pravdová, Lenka ; Lazar, Josef ; Číp, Ondřej ; Kuna, Alexander ; Roztočil, J.
Fibre optics transfers of precise time and ultra-stable optical frequency are gradually becoming part of portfolio of network services of research and educational networks. These national infrastructures very often share fibres with regular data transmission, because of significant share of fibre cost rental on the Total Cost of Ownership (TCO). Situation is very similar in the Czech Republic, where there was more than 3000 km of ultra-stable transmissions within Czech e-Infrastructure, which itself runs over about 5800 km of dark fibre lines.
Highly-coherent laser for precise optical frequencies dissemination
Pravdová, Lenka ; Čížek, Martin ; Hrabina, Jan ; Jelínek, Michal ; Řeřucha, Šimon ; Mikel, Břetislav ; Lazar, Josef ; Havliš, O. ; Altmannová, L. ; Smotlacha, V. ; Vojtěch, J. ; Velc, R. ; Číp, Ondřej
The paper presents a multipurpose laser with a very narrow spectral line, operating at a wavelength of 1540 nm and designed for cooled ions spectroscopy and the dissemination of precise optical frequencies over optical fibre links. The optical frequency of a commercial single-mode laser (NKT Photonics Koheras Basik) is spectrally narrowed to the level of several Hz using a high-quality optical resonator as an optical reference and an acousto-optic modulator as an active control element. The optical resonator is made of a low length thermal expansion coefficient material and is placed in a multi-shell vacuum chamber providing a stable operating environment. Optical frequency stabilisation uses PDH (Pound-Drewer-Hall) modulation and detection technique.
Free-space optical link fro coherent transfer
Hrabina, Jan ; Čížek, Martin ; Barcík, P. ; Kolka, Z. ; Skryja, P. ; Wilfert, O.
The dissemination of precise optical frequencies and time has an irreplaceable role in many applications (scientific experiments in time and frequency metrology, security of critical infrastructures, synchronisation of navigation systems, sensors). We must deploy a different transmission type where optical fibre links cannot be used. The paper describes the possible distribution of stable optical frequencies by the free-space optical link between FEEC BUT Brno (responsible for development and operation of FSO units) and ISI CAS CR (responsible for optical laser source, optical fibre links, data processing).
Infrastructure for accurate time and coherent frequency transmission using a multi band
Havliš, O. ; Vojtěch, J. ; Číp, Ondřej ; Čížek, Martin ; Hrabina, Jan ; Pravdová, Lenka
The poster describes the infrastructure for transmission of accurate time and coherent frequency using multiband, i.e. in a dedicated part of the optical spectrum in C, L and S bands, where bidirectional transmission is carried out on the in-house developed Czech Light system.
Phase coherent link between ISI and BEV
Čížek, Martin ; Pravdová, Lenka ; Hrabina, Jan ; Lazar, Josef ; Číp, Ondřej ; Havliš, O. ; Altmannová, L. ; Smotlacha, V. ; Vojtěch, J. ; Pronebner, T. ; Aeikens, E. ; Premper, J. ; Mache, W. ; Niessner, A. ; Schumm, T.
The paper deals with the current state and the first experiments performed on a 232 km long cross-border phase-coherent line between ISI in Brno and BEV in Vienna. This line is the first operational segment of the planned network for mutual comparison of different types of optical atomic clocks between ISI (Ca +), BEV (Cs) and Atominstitut (Thorium) in Vienna. At all workplaces, local highly coherent lasers (spectral line width in the order of Hz or better) will be synchronized with the link output. This network of synchronized lasers will serve as a transfer medium for the mutual comparison of optical atomic clocks in individual laboratories.
Modelling of quantum dynamics in anharmonic potentials using model of interacting harmonic oscillators.
Kubíček, Václav ; Čížek, Martin (advisor) ; Houfek, Karel (referee)
Thematically, the work pursues a means of numerical description of anhar- monic molecular vibrations regarding vibronic coupling. The main concern is with the possibility of replacing motion in adiabatic anharmonic potential with a set of vibroni- cally interacting harmonic potentials. The work initially provides an accurately tested implementation of a numerical method for finding stationary states in anharmonic po- tentials. And mainly, there is included a thorough discussion of how well the spectrum and states of the vibranically coupled model correspond to the adiabatic approximation of the same model. 1
Transfigurations of the image of the Czechoslovak Parachutists in Memory and Popular Culture 1945-1989
Špitálník, Zdeněk ; Šafařík, Petr (advisor) ; Čížek, Martin (referee)
Práce se věnuje problematice obrazu československých parašutistů ze Západu v poválečném Československu. Časový rámec zkoumaného období je ohraničen roky 1945 až 1989. Úvodní část je tvořena přehledem vydané literatury a pokusem o základní periodizaci vymezeného období. Následuje přehled hraných filmů, které se parašutistů týkají a jejich rozdělení do kategorií, dle prostoru, který je jim věnován. Další část se zabývá muzejním expozicím, které se parašutistům věnovaly. Své místo mělo připomínání parašutistů ze Západu i v československé armádě. Poslední část se věnuje vizuálním připomínkám parašutistů ve veřejném prostoru. Již v prvních poválečných měsících se začaly odhalovat na řadě míst republiky pamětní desky, připomínající narození, či smrt některých padlých parašutistů. Nejvýznamnějším místem pro setkávání parašutistů v den smrti jejich kamarádů byl kostel sv. Cyrila a Metoděje, vždy s účastí veřejnosti a často i vládnoucího aparátu. Cílem práce je vysledovat na výše zmíněných oblastech proměny obrazu parašutistů ze Západu a jejich zasazení či vytěsnění z kolektivní paměti.
Anglo-French defence cooperation as reaction to defence spending cuts
Zajíček, Jakub ; Váška, Jan (advisor) ; Čížek, Martin (referee)
This bachelor thesis deals with military partnership of the United Kingdom of Great Britain and Northern Ireland with France at the time between the end of the Cold War and the signing of agreements to increase defence cooperation at conference in London in November 2010. This paper analyses the various factors that have contributed to the development of cooperation between these two countries and to aims to prove or disprove the thesis that the reason for an unprecedented convergence of Britain and France in the defence sector in 2010 are budget cuts, with which then British government responded to the economic crisis. This topic is divided into three chapters due to a need of separate analysis of individual factors. In the first part the study deals with the dynamics and development of military cooperation between both countries after the Cold War, with emphasis on the conclusions of the London summit in 2010. The second part analyses the financial situation of the Ministry of Defence in the period since 1990. The corresponding chapter examines the response and specific measures of the Ministry of Defence to a lack of resources to meet the required demands and the reasons why the development of cooperation between Britain and France had not occurred previously. The third part is devoted to the...

National Repository of Grey Literature : 198 records found   1 - 10nextend  jump to record:
See also: similar author names
21 Čižek, Martin
21 ČÍŽEK, Martin
2 Čížek, Matěj
1 Čížek, Michael
5 Čížek, Michal
1 Čížek, Mikuláš
1 Čížek, Milan
2 Čížek, Miroslav
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