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Passive capturing probe for IEEE 802.11 standard
Partnov, Denys ; Kubánková, Anna (referee) ; Pospíšil, Jan (advisor)
The bachelor's thesis deals with a general description of the 802.11 protocol, where the individual layers on which the protocol works are explained and described. Attention was also focused on the possibilities of securing wireless traffic. The practical part then deals with the creation of a complete tool for passive interception of traffic in IEEE 802.11 networks. Where it is mainly about processing traffic statistics. The resulting program, written in Python, allows the user to display current information such as: number of transmitted frames, channel, band, received signal strength, and more. Subsequently, the results can be displayed in the form of graphs. As part of the test measurement, the correct functionality of the program was verified.
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Comparation of Models for Datamining
Pospíšil, Jan ; Bartík, Vladimír (referee) ; Lukáš, Roman (advisor)
This thesis focuses on comparing of the datamining models features depending on the different databazis topology. The objekt was to find key features that at most involve the accuracy of classification. Thesis is composed from chapters in a way that even a non-professional or even a complete laik could understand the object and could find theese thesis results useful. In the beginning the reader is beeing made familiar with all the background information about datamining and its models and algorithms, the second part denotes about the model comparison and discusses its results.
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Localization in LoRaWAN technology
Pospíšil, Jan ; Hošek, Jiří (referee) ; Fujdiak, Radek (advisor)
The diploma thesis in theoretical part focuses on LPWAN in general, meaning the low power wireless device falling into IoT category with a focus on LoRaWAN. The second half of the theoretical part focuses on describing localization techniques and principles in general and selection of one suitable technique for implementation in LoRaWAN. The practical part focuses on the proper HW customizations to enable the localization in this network. There are also described all the steps needed to build the whole working LoRaWAN network. The TDoA localization algorithm is described, the functionality is verified by simulation and also by testing under real conditions. In the end, the results are explained, the shortcomings of the technology are described and finally a suggestion for improvement is provided.
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The Architecture of Fun
Lysenko, Mariya ; Pospíšil, Jan (referee) ; Mléčka, Jan (advisor)
Nowadays the evolution of civilization gives us the opportunity to have more and more free time and fun is taken as just like one of the opportunities how time can be used. Architecture going to be only a tool for developing and promoting business within amusement parks. But how does entertainment affect us? Do we need have fun? And what else can give a person a symbiosis of joy and architecture? The aim of this work is to analyze the problem of relations between fun and architecture and suggest a solution in a specific architectural intention.
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Perovskite materials
Gavranović, Stevan ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
This bachelor´s thesis is focused on a study of electrical properties of perovskite single crystals prepared by inverse temperature crystallization (ITC). Measurements were done on the organic-inorganic halide perovskite monocrystal MAPbBr3 and on the completely inorganic halide perovskite monocrystal CsPbBr3. Crystalline structure and chemical composition of prepared single crystals were determined using x-ray diffraction analysis. Current-voltage characteristics of perovskite monocrystals were measured using solar simulator. Hole carrier mobility were calculated from determined current-voltage characteristics using SCLC method. Furthermore, the dependencies of dielectric permittivity on frequency of alternating current were measured. MAPbBr3 single crystal showed better electrical properties (higher hole carrier mobilities) than CsPbBr3.
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Study of optoelectrical properties of organic semiconductor thin film layers
Pospíšil, Jan ; Weiter, Martin (referee) ; Zmeškal, Oldřich (advisor)
The thesis is focused on the study of electric and dielectric properties of thin film organic materials that can be used as an active layer of photovoltaic cells. Primarily were studied the properties of the layers on the glass substrates, which consist of a thin active layer of phthalocyanines. On the samples were first measured current-voltage characteristics (in the dark and during the exposure) and the basic parameters of the photovoltaic conversion were determined. Finally were measured frequency dependencies (impedance spectra, in the dark and during the exposure) and the parameters of a model of the structure with organic semiconductor were determined. The obtained results will be used to optimize the properties of photovoltaic cells.
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Flood prevention by using biotechnical measures
Pospíšil, Jan ; Pavlík, František (referee) ; Dumbrovský, Miroslav (advisor)
This thesis investigates the design of complex systems-natural flood control measures in the area of the cadastral municipality Jeseník nad Odrou. Based on the analysis and exploration of the territory, it was suggested a possible solution by erosion and hydrological GIS tools. To identify areas at risk of erosion and runoff conditions were used a digital elevation model, Wischmeier-Smith equation and model DesQ. Subsequently, the effectiveness was evaluated by comparing the results navžených measure erosion and runoff conditions before and after measures.
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Study of electrical properties of thin polymer films
Pospíšil, Jan ; Vala, Martin (referee) ; Zmeškal, Oldřich (advisor)
The thesis is focused on the study of electric and dielectric properties of thin-film organic materials that can be used as an active layer of photovoltaic cells. Primarily were studied the properties of the layers on the PET or glass substrate, which consist of a thin active layer of polymethylphenylsilane (PMPSi) or derivatives of diketopyrrolpyrrole (DPP). On a selected sample were first measured current-voltage characteristics and current dependences on time at constant voltage (relaxation characteristics). Finally were measured frequency dependences (impedance spectra) and their relaxation characteristics too. The measured data were evaluated using the methods of fractal analysis in HarFA. The results will be used to optimize the properties of photovoltaic cells.
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Study of electrical and dielectric properties of ionic liquids
Mitáčková, Martina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
This bachelor thesis is focused on the study of electrical and dielectric properties of ionic liquids. Two types of OECT substrates with different semiconductor channel lengths made of PEDOT:PSS were used to measure these properties. The dielectric properties were measured by impedance spectroscopy, where the dependence of the impedance value and its phase angle on the voltage frequency was measured. It was found from V-A characteristics, that the best closing of semiconductor layer occurs at a positive UGD voltage. The switching speeds of different ionic liquids were compared for this voltage.
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Study of transistor properties with ionic liquids
Mitáčková, Martina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
This diploma thesis is focused on the study of electric and dielectric properties of transistors based on ionic liquids. The measurements were performed on organic electrochemical transistors with a semiconducting channel made of PEDOT:PSS, which were firstly prepared on ITO substrates, later they were printed using 3D print. Ionic liquid NO4 (1-butyl-3-methylimidazolium hydrogensulfate) was used for measuring of the properties. Electrical properties were determined by measuring volt-ampere characteristics, dielectric properties were measured by impedance spectroscopy.
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