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Unit for stabilizing optical frequency combs
Hucl, Václav ; Čížek, Martin ; Šmíd, Radek ; Lazar, Josef ; Číp, Ondřej
Optical frequency synthesizers (femtosecond combs) are used mainly in the field of precise measurement of optical frequencies, laser spectroscopy and interferometer distance surveying. The repetition and offset frequencies belong to main controlled parameters of such synthesizer. These two parameters need to be locked to ultra-stable frequency standards i.e. H-masers, Cs- or Rb- clocks. We present the complete digital signal processing chain for phase-locked loop (PLL) control of the repetition and offset frequency. The setup is able to overcome some dropouts causes the femtosecond laser instabilities. The presented work gives the possibility of long-time operation of femtosecond combs which is necessary when the optical frequency stability measurement of ultra-stable lasers is performed.
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The history and benefits of CT as an examination method
Melicharová, Ivana ; Adla, Theodor (referee) ; Bruna, Josef (advisor)
Historical development and contribution ct as investigative method My baccalaureate work is divided to the several part. At the beginning I'm deal with case - history computed tomography, where I'm mention names of physicists that the about discovery tomography deserved. Further I'm described structure computed tomograph, which to be almost near of all apparatus the same, only happens to perfection. It is perceptible near characterization separate generations CT apparatus, step by step escalate numbers of detectors and investigation happen for patients more convenient and thrifty in taken radiation dose. To investigation computed tomography is necessary application contrast medium, described an forms version, type contrast medium and their function. Work finishes summary of radiation empty weight for patients, scope of employment radiological assistant in the workplace of computer tomography and it's round off characterization computed tomography with dual energy of radiation. Powered by TCPDF (www.tcpdf.org)
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Local ties controlin application of laser time transfer
Kodet, J. ; Schreiber, U. ; Eckl, J. ; Procházka, I. ; Pánek, Petr
In many fundamental physical experiments time plays an important role. The standard way for the comparison of time and frequency is the application of GNSS signals and the Two-Way Satellite Time and Frequency Transfer - TWSTFT. This technique is based on radiofrequency signal transmission. Recently, there was a rapid increase of optical time comparison development, which uses the Satellite Laser Ranging network (SLR). Currently the French project T2L2 is in operation on board of Jason 2 and the European Space Agency project ELT in support of the Atomic Clock Ensemble in Space (ACES) is under development. The goal of both projects is the time synchronization with a precision below 40 ps rms and an absolute error well below 100 ps. Comparing the results of the optical time transfer with the GNSS time comparison requires unprecedented control of the local ties between the different observation techniques. One of the possible methods is the application of the Two Way Time Transfer (TWTT) on a single coaxial cable. Such a system can be implemented using two or more event timers, which are interconnected by a standard coaxial cable.
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Nonlinearity in the course of acqusition date in optical coherence tomography
Kadla, Jan ; Kolář, Radim (referee) ; Kuna, Zdeněk (advisor)
This bachelor thesis builds on my semestral work, thus provides a description of the problem of optical coherence tomography imaging system in terms of a brief historical development, structural parts and modifications. Previous work is supplemented by a more detailed description of data acquisition and especially signal processing. I present examples of the clinical and research application of this technology, and try to objectively refer to its advantages and disadvantages. Chapter dedicated to the description of a practical measurement explains selected data collection procedure and clarifies their following processing. At the end of the work are summarized the results achieved, including the considerations of potential errors during the measurement.
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Intimate illumination
TICHÁČKOVÁ, Barbora
The Work in the first half deals with the theory of light, answering the question what the light is. It thus encompasses the physical study of light. A large part is also devoted to optics and its history. In the second half of the work we can find chapters that deal with the issue of light in art, accordingly the light as an expressive element of art and also the development of composition of light in the history of visual culture. Not even the theme of light in photography was left out and that is together with the drawing techniques the base of the practical part of this thesis. The analysis concludes with a case study which deals with the composition of light in the medium of drawing.
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Application versatile module LabJack\hindex{TM} in education of physics
PŘIBYL, Vojtěch
Theme of this thesis is using of universal module LabJack U3-HVTM as support for physics lessons. This thesis describes the universal module LabJack U3-HVTM and evaluation method of measured value on the computer screen using software eSimLab. To all physical tasks is described path of signal with measured string from developed sensor until evaluation of signal in the computer. In the thesis is specifically described a function of developed sensors of physical quantities, there are subscribed diagrams including PCB and parts list. The thesis is including designed physical tasks for monitoring of atmospheric pressure, temperature, wind direction, sunshine duration and the role of measurement of the signal on the optical transmitter using the developed sensors and universal module LabJack U3-HVTM.
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Business valuation - DUPI obchodní spol. s r. o.
Trpáková, Olga ; Jurečka, Jan (advisor) ; Svobodný, František (referee)
The aim of the diploma paper is to find out the objectified value of the DUPI company (to the date of the valuation). I tried to specify the future of the company by the means of financial analysis, strategic analysis, analysis and realistic prognoze of generators leading into complex financial plan. The presumption of limited lifetime supported the choice of amortization value as the main value method. After preliminary estimation of maximum presence period on the market and generating of net incomes it was possible to estimate the liquidation of the company in 2009 when amortization and objectified values represents 13, 370, 000 CZK. The content and resumes will only be used for internal use of the company and the present owners to realize the final steps.
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Measuring of signals on biological objets
JŮZA, Zdeněk
Master thesis with the name Measuring of the signals on the biological objects concerns with some ways of monitoring the signals on the biological objects: optical method of measuring EKG on the insects, thermografical method of measuring EKG on insects, EKG, EEG, EPG. In the thesis is mentioned also the problematics of measuring the small voltages with the electrodes in the electrolyte. In the thesis is also the construction of the EKG, which was used for measurement on people, insect and there are also added two measurement reports. There is also shown the construction of the datalogger ATmega for the EKG recording. The thesis is concerning with the history of microprocessors, basic structure of the microprocessors of the AVR family, the division of the microprocessors AVR atmel and description of the two development workspaces AVR studio and Bascom. In the thesis is also shown the syntax of the Bascom programming language.
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