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Laboratory workplace for measuring performances of DVB-T2/T2-Lite
Krejčíř, Dominik ; Kufa, Jan (referee) ; Polák, Ladislav (advisor)
This thesis deals with proposal and realization an appropriate measurement workplace to measure performances of DVB-T2 and DVB-T2-Lite. Both systems for terrestrial digital video broadcasting are described. It is possible to measure objective parameters and evaluate the quality of DVB-T2/T2-Lite signal subjectively. The proposed concept was verified by a set of experimental measurements, which is divided into four scenarios. The measurement focuses to parameters of Set-Top-Boxes. The measurement allows to test and compare Set-Top-Boxes.
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Design of class AB stereo audio power amplifier
Zatloukal, Tomáš ; Polák, Ladislav (referee) ; Brančík, Lubomír (advisor)
The following work deals with design of class AB low-frequency amplifier, which is appropriately supplemented by correction Pre-amplifier and inrush protection circuit. The original schematic from prof. Leach was edited to fulfill task and to be easily completed from discrete components. The result of this work is the final design of power amplifier and correction pre-amplifier, protection circuit for speakers and power supply. As a next part, the design of printed circuit boards will be described together with assembling and mounting of boards in a construction box. Power amplifier will be verified by simulation and hardware measurements.
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Signal propagation in wireless communication systems IEEE 802.11
Vyčítal, Jaroslav ; Fliegel, Karel (referee) ; Polák, Ladislav (advisor)
This paper deals with the propagation of waves. Here is the wavelength distribution according to the wavelength. It focuses on the UHF and SHF band in which IEEE802.11n operates. Contains model breakdown by cell type. Describes which propagation methods are dominant in the cell type. Several propagation patterns are presented, which are then modeled in Matlab environment.The models are then compared to experimental measurements.
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Model of physical layer of communication system IEEE 802.11af
Saprykin, Yaroslav ; Ulovec, Karel (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with analysis, modeling and simulation of the IEEE 802.11af wireless communication system on the physical layer. When designing the solution, it is necessary to understand in details the features and specifics of the IEEE 802.11af system. The work is primarily describes the transmitting part of the communication system with emphasis on processing IEEE 802.11af signal. Subsequently the block diagram and the basic model are created for the transmitting and receiving parts in SISO and MISO broadcast modes. The model is implemented with graphical user interface in the MATLAB programming environment. This application is used to explore the features and performance of the IEEE 802.11af based on its system parameters. System parameters are user configurable what allows to simulate different scenarios. The application also supports simulation of fading channel.
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Model of physical layer of communication system IEEE 802.11ah
Jurák, Petr ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the analysis of the IEEE 802.11ah wireless communication system. For such a purpose, an appropriate simulation model in program environment MATLAB is created. The first part of thesis focuses on the IEEE 802.11 standard. Basic blocks of the transmitter and receiver are described. Attention is also devoted on the brief description of considered transmission channels. The second part contains the description of the proposed and realized simulation model in MATLAB. Individual blocks of the simulation model are described in details. Finally, the obtained simulation results are evaluated and discussed.
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Highly siderophile element and Re-Os isotopic geochemistry of carbonatites and associated alkaline rocks from selected occurrences in India
Polák, Ladislav ; Ackerman, Lukáš (advisor) ; Krmíček, Lukáš (referee)
Carbonatites are intrusive and extrusive rocks with content of carbonate minerals > 50% predominantly derived from upper mantle. They represent a potential economical source for platinum- group elements as can be seen on actively mined sites like Phalaborwa in South Africa or Ipanema in Brazil. The first complete dataset for highly siderophile element (HSE) abundances along with their 187 Os/188 Os compositions for carbonatites, silicocarbonatites and associated alkaline rocks (pyroxenite, syenite, monzogabbro and tonalite) from two Neoproterozoic (~ 800 Ma) suites from Samalpatti and Sevattur, Tamil Nadu region in south India is presented. The data were obtained by a standard methods in involving decomposition of samples in Carius Tubes, Os separation by CHCl3 following microdistillation and Ir, Ru, Pt, Pd isolation by anion exchange chromatography. The data show that carbonatites from Samalpatti and Sevattur are characterized by very low HSE contents, lower than other mantle-derived mafic melts such as basalts or komatiites. Suprachondritic OsN/IrN ratios might suggest that carbonatites are able to concentrate not negligible amount of Os. Due to high, non-uniform 187 Os/188 Os ratios, we suggest that the source of carbonatitic melts was largely heterogeneous with high contribution of crustal...
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Leachability and gastric bioaccessibility of contaminants from the waste products of Ni metallurgy
Polák, Ladislav ; Ettler, Vojtěch (advisor) ; Suchá, Veronika (referee)
Due to mining and processing of sulphide laterite and sulphide ore leads to environmental contamina- tion by metals and metalloid elements. To determine how the contaminant leached and how can da- mage its nearby area, serves leaching experiments. In order to determine the potential impact on hu-man health can be used in leaching tests simulated gastric, gastrointestinal and pulmonary solutions. The aim of this bachelor thesis is to make these leaching tests to determine how a metallurgical waste affect the environment or the population in the region (eg. workers in the steel industry). The results show that the greatest exhibit leachability have ash. The limit values for hazardous waste in excess of Ni (4250 mg/kg) for inert waste Zn (22.3 mg/kg) and Cd (0.51 mg/kg). Gastric leaching tests show that the greatest health risk exists for Al TDI (181 μg/day), Ni (BE 324 μg/day) and V (TDI of 0.78 μg/day). Tolerable daily intake (Tolerable Daily Intake, TDI) is the estimated amount that a person can endure in the long term without harming the body. Background exposure (BE) is the dose or amount, to which the individual is exposed to. As a result of the extraction to the surroundings gets more contaminants than would be obtained by natural processes (erosion, leaching by water).
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Coexistence of wireless communication systems and LTE in the ISM band
Mikláš, Michal ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This bachelor thesis deals with a definition, description and measurement of coexistence scenarios which can occur between LTE and WLAN (technology IEEE 802.11xx) wireless communication systems in the ISM band. Based on the common radio frequency (RF) bands, used by these systems, different coexistence scenarios are defined. Appropriate measurement testbed and method are proposed to measure coexistence between LTE and WLAN systems. Functionality of the proposed measurement testbed has been proved and extensive measurement of previously defined coexistence scenarios has been done. The obtained results are evaluated in details.
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Comparison of VP9 and H.265 encoding standards
Fendrich, Vítězslav ; Boleček, Libor (referee) ; Polák, Ladislav (advisor)
This bachelor thesis deals with a comparison of the features of video coding standards VP9 and HEVC (H.265), developed to encoding videos mainly in high resolution. Theoretical part of this work is focused on the presentation and description of both VP9 and H.265 video codecs. Furthermore, objective and subjective metrics for video quality assessment are briefly described. Practical part of this work deals with an evaluation of the quality of video sequences, encoded by VP9 and H.265, with objective metrics and subjective metric. The description of the encoding process using VP9 and H.265 is also included. Proceeding of subjective tests in laboratory conditions is also described. Achieved results are clearly presented and discussed.
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Embedded video processing for surveillance systems
Gerych, Lukáš ; Polák, Ladislav (referee) ; Frýza, Tomáš (advisor)
The thesis includes the design and implementation of embedded system to capture static scenes and image evaluation for the surveillance system. It is performed on a tiny computer Raspberry Pi with ARM processor. Methods are provided for various types of detection in the image and their implementation using OpenCV libraries. It also deals with ways to access the system for the control and viewing records of detections.
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