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Laser cooling of the trapped ions for frequency and time metrology
Číp, Ondřej ; Pham, Minh Tuan ; Čížek, Martin ; Lešundák, Adam ; Hucl, Václav ; Hrabina, Jan ; Řeřucha, Šimon ; Jedlička, Petr ; Lazar, Josef
In the laser cooled trapped ions field current research is oriented to yield isolated ions in their basic state of the motion. The detection of the Doppler cooled iont excitation to its quadrupole transition of the electronic structure gives the opportuniny to stabilize highly coherent lasers of the optical frequency of the hundreds of THz. This way a new standart of the time or optical frequencies called „Optical atomic clock“ can be defined. Institute of the Scientific Instruments in Brno in the cooperation with the Department of the Optics of the Palacky University in Olomouc implemented a unique research infrastructure for laser cooling of 40Ca+ ions and subsequent experiments of the quantum mechanics and spectroscopy in a joint laboratory in Brno. Currently 40Ca+ ions are routinely generated and captured. The Doppler cooling of those ions is performed using dipole transition at a wavelength of the 397 nm. Also detection and spectroscopy of the electronic structure of the ion and the presence of his dark resonances is implemented.\n
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Automatic system for gauge blocks calibration optimized for legal length metrology
Buchta, Zdeněk ; Šarbort, Martin ; Čížek, Martin ; Hucl, Václav ; Řeřucha, Šimon ; Pikálek, Tomáš ; Dvořáčková, Š. ; Dvořáček, F. ; Kůr, J. ; Konečný, P. ; Lazar, Josef ; Číp, Ondřej
This paper presents a contactless system for automatic and contactless gauge blocks calibration based on combination of laser interferometry and low-coherence interferometry. In the presented system, the contactless measurement of the absolute gauge block length is done as a single-step operation without any change in optical setup during the measurement. The optical setup is combined with compact gauge block changer with capacity 126 gauge blocks, which makes the resulting system fully automatic. \nThe paper also presents in detail a set of optimization steps which have been done in order to transform the original experimental setup into the automatic system which meets legal length metrology requirements. To prove the measurement traceability, we conducted a set of gauge block length measurement comparing data from the optimized system and the established reference system and TESA–UPC operated in Czech Metrology Institute laboratory.
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Records of stocks in the acquisition phase and phase output to consumption in the books chosen economic operator
ČÍŽEK, Martin
This bachelor thesis focuses on stock accounting records in the phase of purchasing and releasing in a certain company. This thesis is divided to theoretical and practical part. Stocks are important for manufacturing companies. The theoretical part describes demarcation of stock and its basic separation, different methods of stock evaluation during the purchasing and releasing, methods of stock accounting, stocks of own production, accounting transactions at the end of the accounting period, discounts on purchased stocks and stock management. The aim of this thesis is to perform a practical application of stock evaluation based on the previous theoretical knowledge. The practical part firstly describes a specific company which was chosen for the study. This company is HELUZ brick industry v. o. s.. The practical part presents a comparison of methods of stock evaluation during the releasing based on the accounting records received from the company. The methods of stock evaluation used in thesis are: weighted arithmetic average, FIFO and LIFO. On the first place in rating is FIFO, the second is weighted arithmetic average and the last is LIFO. Based on ratind I can reccomend method FIFO as the best for the company.
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Spectral analysis of sound in spatial acoustics
Křenek, Jakub ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This thesis is focused on the basics concepts of room acoustics and used sound level meters. The first part focuses on the spatial acoustics and acoustic quantities used in it. Next part of thesis describe the structure and features of sound level meters. Following chapters are concerned on the PULSE system architecture and data analysis. PULSE platform contributes multi-spectral analyzer type 3560B PULSE, programming environment LabShop and microphones for difuse and free fields. The practical part describes the installation, setup and the measurement of reverberation time in the Labshop environment.
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Doppler blood flow indicator
Mojžíš, Karel ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This bachelor´s thesis deals with basis of ultra-acoustics. The project presents basic information about Doppler effect. It describes the methods of processing and analyzing of velocity and direction of blood at doppler’s systems with modulated and unmodulated carrier wave. The project presents the system design of non-directional doppler indicator with unmodulated carrier wave for 8 MHz frequency, generating intensity of ultrasound 100 mW/cm2 and diameter D-shaped transmitting transducer 8 mm. This bachelor's thesis is concerned with circuit solution of a battery powered blood flow indicator with digital display. All the function blocks of the system are experimentally measured and their function is verified. The thesis contains complete materials for the construction of the doppler blood flow indicator.
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Spectral analysis of sound in spatial acoustics
Křenek, Jakub ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This thesis is focused on the basics concepts of room acoustics and used sound level meters. The first part focuses on the spatial acoustics and acoustic quantities used in it. Next part of thesis describe the structure and features of sound level meters. Following chapters are concerned on the PULSE system architecture and data analysis. PULSE platform contributes multi-spectral analyzer type 3560B PULSE, programming environment LabShop and microphones for difuse and free fields. The practical part describes the installation, setup and the measurement of reverberation time in the Labshop environment.
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Ultrasound blood flowmeter
Mojžíš, Karel ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This master's thesis is concerned with the basis of ultra-acoustics and it explains the application of Doppler effect in medicine as a diagnostic method used for measuring blood flow velocity in blood vessels. The thesis also presents Doppler systems used for diagnostic purposes. It describes the principles of these systems, shows accompanying flowcharts and explains the function of these systems. There is also included the system design of the whole ultrasonic blood flow velocity meter. The system has been designed for the specified parameters with continuous 4 MHz operating frequency, generated intensity of ultrasound 100 mW/cm^2 and diameter D-shaped transmitting transducer 8 mm. In the design of personal solution there are described all the function blocks of the ultrasonic meter. There is also described the choice of appropriate components and designed all the required supply voltages. All the function blocks of the system are experimentally verified. The system has been designed with acoustic intercept and the resultant velocity curves are displayed on software oscilloscope on PC.
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Secure Authentication and Access Control in Web Applications
Čižek, Martin ; Pecho, Peter (referee) ; Samek, Jan (advisor)
This thesis deals with security of web based applications and their access controlling. The work describes security of applications in WWW environment and security elements that help us to secure those systems against possible attacks. Authentication methods used in PHP applications are described in more detailed way with their advantages and disadvantages with consideration on security and usability.
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Parallelization of Ray Tracing
Čižek, Martin ; Juránek, Roman (referee) ; Herout, Adam (advisor)
Ray tracing is widely used technique for realistic rendering of computer scenes. Its major drawback is time needed to compute the image, therefore it's usually parallelized. This thesis describes parallelization and ray tracing in general. It explains the possibility of how can be ray tracing parallelized as well as it defines the problems which may occur during the process. The result is parallel rendering application which uses selected ray tracing software and measurement of how successful this application is.
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Thermoacoustic measurement of ultrasonic power
Kučera, Václav ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
The thesis deals with ultrasound intensity and power measuring methods of the medical diagnostic systems, especially with thermoacoustic method. Then the concept of thermoacoustic sensor is processed and it is checked by comparison with the power of ultrasound system measured by the hydrophone in ultrasonic measuring tank. In the leading chapter basic parameters of general ultrasonic field are described. Next part deals with particular ultrasound intensity and power measuring methods. The last part deals with projecting of the thermoacoustic sensor, measuring with this sensor, measuring with hydrophone and comparison of this measurements.
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