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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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Co-existence of the still used and upcoming digital terrestrial television and mobile communication services
Plaisner, Denis ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This work deals with exploring, measuring and evaluation of possible coexistence scenarios between terrestrial digital TV (DVB-T/HT2) and mobile wireless services (GSM, LTE), which can occur in a shared RF frequency bands The DVB-T, DVB-T2 and LTE standards are briefly described. RF band, where these systems are operated, are outlined too. . There are defined different coexistence scenarios. For the measuring, monitoring and evaluation of these scenarios, an appropriate laboratory workplace is proposed and realized. Results from the measurements show various influence of interfering mobile services on the interacted DVB-T/H system, depending on the considered coexistence scenario.
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Measurement of diversity broadcasting in DVB-T2 standard
Koblischka, Vítězslav ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This bachelor thesis compares standards for digital and terrestrial television broadcasting of first-generation DVB-T and second-generation DVB-T2. It focuses particularly on the impact of interference in transmission media simulated by transmission channels for fixed, portable and mobile reception of terrestrial digital signal. Furthermore, the thesis compares SISO broadcast with the diverse MISO broadcast in DVB-T2 standard and evaluates the impact of the mode on error rate depending on the selected transmission channel and systems parameters that were used.
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Two-way stereo speaker system
Kočvara, Pavel ; Polák, Ladislav (referee) ; Kratochvíl, Tomáš (advisor)
The Bachelor thesis deals with design of a passive two-way stereo speaker system with performance 50 W RMS / 8 for normal domestic use. With respect to its sensitivity 90 dB/W/m mid-range speakers Beyma 5MP50/N and tweeter Beyma T2030 were used. The enclosure is a type of bass-reflex and it is made of MDF material with internal damping from polyurethane coat.
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