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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.
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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.
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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.
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The influence of assisted vaginal delivery on newborn's adaptation
Michálková, Tereza ; Pařízek, Antonín (advisor) ; Vojtěch, Jiří (referee)
The aim of the bachelor's thesis is to introduce assisted vaginal delivery and to relate the end of delivery by the extraction method to the condition of the newborn immediately after delivery. The thesis is divided into theoretical and practical parts. The theoretical part is focused on defining the concepts on the topic of childbirth and birth mechanism. Furthermore, it deals with the characteristics of vaginal operative delivery and the characteristics of different extraction equipment methods - technique of execution, indications, contraindications and complications. Furthermore, the thesis is focused on defining basic concepts about the newborn, both general and more specific to the topic of the thesis. An important chapter in the neonatal section is the postpartum adaptation and injury of the newborn. The practical part is conceived as a research part and analytical data collection from medical records and the hospital information system Medea was used for this purpose. The research was conducted at the Gynaecology and Obstetrics Clinic of the 1st Faculty of Medicine of Charles University and the General University Hospital in Prague. The collected data were processed in the web application for medical research data collection - REDCap. The aim of the practical part of the bachelor thesis was...
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Law principles applied in Islamic banking
Vojtěch, Jakub ; Kohajda, Michael (advisor) ; Kotáb, Petr (referee)
TITLE: Law principles applied in Islamic banking AUTHOR: Jakub Vojtěch DEPARTMENT: Department of financial law and financial science THESIS SUPERVISOR: JUDr. Michael Kohajda, Ph.D. ABSTRACT: This paper aims at starting a deeper academic discussion of the most fundamental principles of Islamic banking and their application. Ther term "Islamic banking" denotes the banking services in compliance with Islamic law and is nowadays a rapidly expanding, global industry based on a traditional fourteen centuries old legal system. The text explains the basic special requirements (Halal, Riba, Gharar, Majsir, Shiraka, Shari'ah Board) for Islamic banks both in terms of defining and describing these principles as well as giving examples and considering acceptability of conventional products from the Islamic point of view. The study serves as a contribution to debate on the new academic and business field of Islamic banking where I am trying to depict the key and distinguishing features of this banking model, provide a comparison of functioning with the conventional counterpart and give some examples of various types of Islamic banking products. Effort has been made also to offer an overview of the Islamic ethical economy which is the philosophical basis for the Islamic banking model and to describe development and...
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Proposal of measures in the low voltage network for the implementation of renewable sources and electromobility according to scenarios NAP SG
Vojtěch, Jan ; Kučera, Michal (referee) ; Ptáček, Michal (advisor)
The thesis analyzes legislative and strategic documents of the European Union and the Czech Republic which set targets in environment and energy area in 2030, alternatively in 2040. The individual chapter is dedicated to national action plans, where the most important is National Action Plan for Smart Grids setting specific requirements for future development of smart grids. The thesis contains analysis of distribution network in the municipality of Následovice and simplifying assumptions for the implementation of calculation. There are also introduced scenarios which have been used for the calculation of the distribution network with its results. Potential defects of the distribution network are commented with suggested solutions. The calculations were repeated to verify the solutions. Results are recapitulated in an individual chapter. Graphical outputs of the calculations can be found in the attachement.
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Transmitting television signal via fiber optics
Abbasi, Farhad ; Vojtěch, Josef (referee) ; Münster, Petr (advisor)
Hlavním cílem této práce je teoretická analýza přenosového DVB TV signálu prostřednictvím optických vláken, analýza sítě CATV a modulační techniky pro její přenos. První částí této práce je zavedení šíření signálů v optických vláknech a pasivních součástech optických sítí, následované obecnými informacemi o digitálním rozhlasovém vysílání, sítí CATV a modulačním formátu pro jejich přenos. V druhé části, která se nazývá praktická část, vysvětluje výsledek měření, který se skládá ze srovnání různých měřicích parametrů, jako jsou "Power SIGNAL", "C / N", "Kanálový výkon" pro rozdílné délky optických vláken.
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Sukuk as Islamic Financial Instruments from the Perspective of Czech and European Law
Vojtěch, Jakub ; Bakeš, Milan (advisor) ; Marková, Hana (referee) ; Radvan, Michal (referee)
Sukuk are a special kind of securities based on Islamic law. Being an up-to-date and increasingly important instrument, sukuk are traded in financial markets of not only Muslim countries. The aim of the dissertation is to review this Islamic legal institute in its entirety and to examine it from the point of view of the Czech and European Union legal regulation of securities and financial instruments. The starting point of the dissertation is the assumption that by studying foreign law and comparing its institutes, it is possible to achieve a better understanding of one's own legal regulation and possibly create new solutions that would otherwise be hidden in the standard context of understanding national law. The dissertation deals with sukuk both in terms of their theoretical definition provided by the Islamic legal theory (the idealistic approach) as well as from the point of view of their actual form in practice as products of Islamic securitization (the pragmatic approach). The analysis of the examined legal institute results in a new definition of the concepts of sukuk and Islamic securitization. The paper further concentrates on the structures of a total of seven main types of sukuk, namely: (i) Sukuk al-Ijarah, (ii) Sukuk al-Murabahah, (iii) Sukuk as- Salam, (iv) Sukuk al-Istisna'a, (v)...
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