National Repository of Grey Literature 134 records found  beginprevious35 - 44nextend  jump to record: Search took 0.00 seconds. 
The study of the electrical and dielectric properties of gas sensors based on ionic liquids
Maráčková, Lucie ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
This diploma´s thesis is focused on a study of electrical and dielectric properties of gas sensors based on ionic liquids. Measurements were done on two different types of OECT substrates (0099 and 0160). Three ionic liquids and physiological solution PBS were chosen as electrolytes. Direct current current-voltage characteristic was measured. Switching rations of transistors with this electrolyte were determined by current-voltage characteristic. Alternating resistivity dependence on frequency were measured as well. Better properties showed OECT 0099 substrates.
ECG quality estimation
Pospíšil, Jan ; Smíšek, Radovan (referee) ; Smital, Lukáš (advisor)
This bachelor thesis deals with the question of estimation of the quality of the ECG signals, which is a key parameter for determining the diagnosis. The theoretical part deals with the basic knowledge concerning cardiac physiology, electrocardiography and finally the types of interferences that can occur during the measurement. The following practical part will deal with the published methods and the proposal of methods for estimating signal quality and their testing on artificial and real data.
Study of dielectrical properties of organic material thin films
Pospíšil, Jan ; Boušek, Jaroslav (referee) ; Mikula, Milan (referee) ; Zmeškal, Oldřich (advisor)
The dissertation is focused on the study of electric and especially dielectric properties of thin film organic materials with their huge potential for optoelectronics and other industrial sectors. The theoretical part deals with the use of organic materials in organic photovoltaic cells, the methods of deposition techniques and characterization. The theoretical knowledge of the dielectric spectroscopy, including methods for determining the physical properties and evaluation of experimental data are also described. The experimental part is devoted to the study of small molecule organic solar cells with bulk heterojunction composed of electron donor molecule of DPP(TBFu)2 and electron acceptor fullerene derivatives, such as PC60BM, PC70BM and TC60BM. The experimental part is divided into two main parts. The first part deals with the study of processes occurring at the interface between the active layer and the contact; the second part is focused on transport processes inside the structure of photovoltaic cells and also contains a study of perovskite solar cells.
Passive capturing probe for IEEE 802.11 standard
Partnov, Denys ; Pospíšil, Ondřej (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.
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.
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.
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.
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.
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.
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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