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BIT ERROR RATE AND AVAILABILITY OF THE ATMOSPHERIC OPTICAL LINKS
Kvíčala, Radek ; Vašinek, Vladimír (referee) ; Fišer, Ondřej (referee) ; Wilfert, Otakar (advisor)
This dissertation deals with the problematic of the free space optical link availability determination. For the presumption of the free space optical link unavailability we have to know statistical distribution of the atmospheric attenuations. In this work is also presented the measurement of these atmospheric attenuations with the specially designed optical link. Measurement is using switching of the two separate transmitters with wavelengths of 830 nm and 1550 nm. Presented statistic distribution let us determine the suitability of the link in the chosen locality during its design. Comparison of our measurement with other models like model based on the meteorological visibility is also presented. The last part of this work is focused on the preconditions for the hi-speed network bit error rate determination. Sample of the bit error rate measurement obtained by our designed bit error rate tester is attached.
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Integrated multichannel audio amplifier for home cinema
Fišer, Ondřej ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
This paper describes complete design of amplifier for home cinema system. Described amplifier has 2 digital inputs (TOSLINK and S/PDIF) and single analog input. With this inputs it is possible to connect amplifier to a source of surround audio 5+1 signal. Paper further discuss design of correction circuits, preamplifier, power amplifier and power source. The whole is controlled by 8-bit microprocessor and has a graphics output implemented through LCD display. The goal of this paper is to design and build high quality amplifier.
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Timer For RC Models
Fišer, Ondřej ; Pospíšil, Martin (referee) ; Šebesta, Jiří (advisor)
This paper describes complete design of timer for RC models. Described timer has three PWM outputs. With these outputs it is possible to connect two independent servo-motors and engine controller. 1 signal. The whole is controlled by 8-bit microprocessor. The time records are stored in external EEPROM, that can be programmed using I2C. Paper further discuss design of programming, which can be easily programmed the memory of EEPROM by the PC or smartphone. The goal of this paper is to design and build high quality RC timer with accessories.
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Modeling of the multichannel optical wireless link
Pavlů, Michal ; Fišer, Ondřej (referee) ; Poliak, Juraj (advisor)
This thesis deals with multi-channel wireless links with a higher range designated for free-space communications in an atmospheric media. Propagation of the optical beam in an atmosphere is analysed and various influences affecting the quality of the transmitted signal are described. The simulation is carried out for dual optical link. Link budget of individual paths working at the wavelengths in the atmospheric windows – 850 nm and 1550nm. It also examined optical intensity distribution of the transmitted beam. At the end of the work performed measurements and simulations verify the accuracy of the components used in wireless link.
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3D models of brain tumors
Fišer, Ondřej ; Novák, Josef (advisor) ; Bohačiaková, Dáša (referee)
Despite intensive research, glioblastoma multiforme remains one of the tumours of the central nervous system with the worst prognosis. The ability of glioblastoma cells to infiltrate brain tissue by forming invasive microtubular structures is stimulated by contact with adjacent non- tumor cells. Intercellular communication and the influence of the extracellular matrix create a specific microenvironment that affects cell signaling, proliferation, differentiation and response to pharmaceuticals. The recurrent form of glioblastoma often displays a much faster progression than the initial disease, which is attributed to the development of resistance to therapeutics and the preservation of the proliferative capacity of some tumour cells. The discovery of the stem- cells ability to self-aggregate in suspension has led to the creation of 3D in vitro models - brain organoids. They are much more complex that the established 2D models and their heterogeneity provides an environment simulating the in vivo state. This thesis aims to describe their use in brain tumour research and techniques for culturing 3D aggregates of neural lineage formed from induced or embryonic human stem cells with respect to their gradually increasing complexity. It also presents methods of addressing issues of hypoxia, organoid...
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We grew up on Sunar-mark. communication in the area of infant formula
Fišer, Ondřej ; Hejlová, Denisa (advisor) ; Halada, Jan (referee)
The bachelor thesis We grew up on Sunar - marketing communication in the area of infant formula examines the issue of advertising infant formula, with special focus on the communication of the brand Sunar. A brief outline of the history of breastfeeding and development of artificial infant formula, offering a comprehensive insight into the subject matter, is followed by a case study of the Nestlé company. This case brought on significant changes in the perception of the issue of infant feeding marketing as well as in the regulations limiting greatly the options of marketing communication in this segment. Important legislation is briefly introduced. The work then presents a concise history of the Hero company and its brand Sunar and in detail analyzes and describes individual elements used in selected samples of advertising; these are placed in a larger social and historical context and confronted on the basis of common marketing communication theories. The work also mentions the most significant non-governmental breastfeeding organizations and their activities. The aim of this work is to explore the communication of the brand Sunar resulting from the consumer perception of the brand and to sum up the facts from the area of communication strategies of infant and child nutrition companies.
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What It Means and How It Is Approached by Financial Regulators
Fišer, Ondřej ; Sejkora, Tomáš (advisor) ; Kohajda, Michael (referee)
The thesis covers the topic of sustainable finance regarding its terminology, policy strategies and overall goals. In addition, it specifically deals with the way sustainable finance is perceived by central banks and other financial market regulators. The first chapter explains terms like "ESG investing," "positive finance," "socially responsible investment, "principles for responsible investing" "or "green finance" and points out the differences between them. The second chapter concerns with sustainable finance policy strategies adopted both by private businesses and public institutions. Mentioned are, among others, the types of ESG screening methods used by investors, the EU Green Taxonomy, the EU Shareholders' Rights Directive and its framework, the European Green New Deal or the concept of a sustainable fiduciary duty principle. It also touches on sustainable, green taxation in the shape of carbon taxes or emission trading schemes. The third chapter explores the objectives sustainable finance try to meet, specifically the ones having to do with climate change. The chapter entails a summary of the potential climate change scenarios as laid out by the Intergovernmental Panel on Climate Change. The fourth chapter deals with the role that central banks can play in sustainable finance as they gradually step...
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The role of the face and the body size in predators' recognition by untrained birds
Fišer, Ondřej ; Fuchs, Roman (advisor) ; Petrusková, Tereza (referee)
The face plays an extremely important role in human communication. It enables individual recognition and provides other information about the person, such as social or emotional information. Human psychology has shown that face recognition uses a specific cognitive process called holistic processing. In recent decades, it has been shown to play an important role in animal communication as well. In the first part of my thesis, I tested whether changing the uniform configuration of a bird's face would affect the ability of the red-backed shrike (Lanius collurio) to recognize a potential predator. Due to unfavourable conditions in both breeding seasons when the experiments were conducted, no firm conclusions can be drawn from the results. They only suggest that the shrike perceives the configuration changes. An essential characteristic of all predators is their size, which affects the ability of prey to defend themselves. Several studies have already found that birds discriminate between different predators of different sizes. In the second part of my thesis, I evaluated experiments in which shrikes were exposed to dummies of two predator species with modified size. The shrikes responded with less aggression to the enlarged jays, whereas aggression increased only slightly to the shrunken crows. Thus,...
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Hybrid Vacuum Tube Amplifier
Fišer, Ondřej
This paper describes the complete design of the hybrid vacuum tube amplifier for home using. The described amplifier has 3 digital inputs (TOSLINK, Sony/Philips Digital InterFace and AES3), a single analog input and a single input for the measuring microphone (for the calibration of the entire system). The paper further discuss the design of a preamplifier for analog inputs, the receiver of digital inputs, DSP circuits, power and head phones amplifier and the power source. The complex audio system is controlled by an 8-bit microprocessor and has a graphics output implemented through an OLED display. The goal of this paper is to design and build a high quality amplifier.
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Optimizing Bias Point Of High Efficiency Class-B Gan Power Amplifier For The Best Efficiency
Fiser, Ondrej
High performance amplifiers are always a demanding component in the world of wireless communication. The amplifier is the heart that drives each radio system. We have designed and developed a high performance one-stage class-B GaN power amplifier for drone applications in the S-band (at 1,6 GHz) with maximum output power 6 W. This paper compare fixed settings of the bias point option and optimized bias point for the best efficiency within the entire output power range. Applying the proposed method, that is particularly advantageous for low power performance to improve efficiency by more than 15 %.
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