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Brain Tumor Detection and Segmentation in Multisequence MRI
Dvořák, Pavel ; Přibil, Jiří (referee) ; Šprláková-Puková,, Andrea (referee) ; Smékal, Zdeněk (advisor)
Tato práce se zabývá detekcí a segmentací mozkového nádoru v multisekvenčních MR obrazech se zaměřením na gliomy vysokého a nízkého stupně malignity. Jsou zde pro tento účel navrženy tři metody. První metoda se zabývá detekcí prezence částí mozkového nádoru v axiálních a koronárních řezech. Jedná se o algoritmus založený na analýze symetrie při různých rozlišeních obrazu, který byl otestován na T1, T2, T1C a FLAIR obrazech. Druhá metoda se zabývá extrakcí oblasti celého mozkového nádoru, zahrnující oblast jádra tumoru a edému, ve FLAIR a T2 obrazech. Metoda je schopna extrahovat mozkový nádor z 2D i 3D obrazů. Je zde opět využita analýza symetrie, která je následována automatickým stanovením intenzitního prahu z nejvíce asymetrických částí. Třetí metoda je založena na predikci lokální struktury a je schopna segmentovat celou oblast nádoru, jeho jádro i jeho aktivní část. Metoda využívá faktu, že většina lékařských obrazů vykazuje vysokou podobnost intenzit sousedních pixelů a silnou korelaci mezi intenzitami v různých obrazových modalitách. Jedním ze způsobů, jak s touto korelací pracovat a používat ji, je využití lokálních obrazových polí. Podobná korelace existuje také mezi sousedními pixely v anotaci obrazu. Tento příznak byl využit v predikci lokální struktury při lokální anotaci polí. Jako klasifikační algoritmus je v této metodě použita konvoluční neuronová síť vzhledem k její známe schopnosti zacházet s korelací mezi příznaky. Všechny tři metody byly otestovány na veřejné databázi 254 multisekvenčních MR obrazech a byla dosáhnuta přesnost srovnatelná s nejmodernějšími metodami v mnohem kratším výpočetním čase (v řádu sekund při použitý CPU), což poskytuje možnost manuálních úprav při interaktivní segmetaci.
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Materials for Supercapacitors
Dvořák, Petr ; Paidar,, Martin (referee) ; Trnková, Libuše (referee) ; Sedlaříková, Marie (advisor)
This dissertation deals with the electrode materials, liquid and gel electrolytes suitable for supercapacitors. In the field of electrode materials were investigated carbon materials based on carbon blacks, expanded and micronized graphite suitable for supercapacitors working on the principle electrochemical double layer. Another area which this thesis deals with are aprotic liquid electrolytes prepared from suitable types of salts and aprotic solvents. The last part is focused on the preparation and subsequent electrochemical characterization of gel polymer electrolytes in order to increase the ionic conductivity of these electrolytes.
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Charger for small accumulators
Dvořák, Pavel ; Zeman, Václav (referee) ; Kolka, Zdeněk (advisor)
Work will address the characteristics of small batteries. They are described types of charging process, charging time and charging currents, depending on their effectiveness. Great attention will be directed to draft Chargers, working in the area of continuous or discontinuous modes. Furthermore, the calculation of individual components and their influence on the running drive. The charger will be simulated by PSpice program and powered photovoltaic. Work will focus on the maximum efficiency when the incident light intensity. With related setting maximum efficiency and maximum power tracking using microprocessor-controlled detention. The charger will detect the input voltage, battery voltage and current. Depending on these values will be changed duty cycle PWM.
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Node localization on the Internet using domain name system
Dvořák, Petr ; Müller, Jakub (referee) ; Komosný, Dan (advisor)
This paper describes various systems that are used to predict delay among nodes . It focuses on systems using for prediction delay artificial coordinate systems, and on the systems, which use physical measurements of delay. Primarily, however, it deals with the King method, which uses the system for translation of domain names - DNS (Domain Name System) to predict the delay. Next, the principle of the King method is outlined in detail. Practical part includes a description of the two created simulations in program Matlab. The first application described simulates the King method principle. The second simulation is then tasked with creating 2D geometric space in which nodes and DNS servers are randomly generated. The result is dependence of RTT prediction accuracy on the number of randomly generated DNS servers. Based on this dependency the method King is compared with other methods in the end.
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Production Planning with the Support of Information System
Dvořák, Pavel ; Marvánek, Karel (referee) ; Videcká, Zdeňka (advisor)
This thesis deals with adding planning to the current information system as requirement by the company. The theoretical part describes the methodes of information systems for the production plan. These tools are mostly general and trying to cover the entire spectrum of manufacturing processes. The practical part is devoted to implementing of the produciton planning. The modul planning is incorporated into the current information system.The modul planning has been implementing for efficiency of the systemand faster throughput of the orders the company.
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Study of Properties of Surface Plasmon Polaritons on Magnetic Materials
Dvořák, Petr ; Schmidt, Eduard (referee) ; Kalousek, Radek (advisor)
The diploma thesis deals with the experimental study of surface plasmon polaritons (SPPs) on nano-structures with the Au/Co/Au multilayer. Plasmonic structures were prepared by the electron beam lithography and by the focused ion beam. A Scanning optical near-field microscope was used for detection of surface plasmon polaritons. SPPs were confirmed by the experiment with different polarizations of the illuminating light. Furthermore, differences in plasmon interference wavelengths was measured for different surface dielectric functions. Finally, the decantation of the SPPs interference image was measured in dependence on the external magnetic field.
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Principals, switching functions and routing techniques in computer networks
Dvořák, Pavel ; Pelka, Tomáš (referee) ; Polívka, Michal (advisor)
This bachelor thesis consider main principles and function of active network components. Mainly is intent to component working on the third level of referential model ISO/OSI, router. There are described its main parts and more closely charactered routing protocols. Then is verified the ability of dynamic routing to react to failure in the network and there is measured the reaction time of crossing to secondary route when using different routing protocols. Another part of the thesis is focused on the questions of Quality of Service (QoS) and its support in computer networks. There are explored various ways of the QoS configuration on the routers and the proper of them is chosen and applied to the test network.
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Audio amplifier controlled by the IP protocol
Dvořák, Petr ; Schimmel, Jiří (referee) ; Kouřil, Jiří (advisor)
The bachelor thesis is intent on projection and realization of a device whitch is capable of communicate with a remote client through the Ethernet making use of the protocol set TCP/IP. This communication will be used for the control of analog and digital outputs of the device, which is able to be attached to any amplifier of audio signals. One of used protocols is UDP. This protocol is closely described, because it is used for transfer of data controlling outputs. The whole device is controlled by microprocessor ATmega32, which operates the communication with the ethernet interface through the controller ENC28j60, the communication with the D/A converters MCP4922 and controlling of digital outputs and a display. The device has its own IP and MAC address for identification in the network. It is possible to edit both addresses in the menu of the device with the help of the module LCD, the display of 2x16 characters with fours buttons. The audio amplifier staffed by the voltage controlled by the computing amplifiers SSM2018T is connected to this device. The amplifier is proposed as six-channel with symmetric inputs through the connectors XLR and unsymmetric outputs through the connectors CINCH. The operating programme which is able to be run on PC with the operating system Windows is necessary for the remote control of the device in the network and all functions of the device are controlled by this programme. This programme enables to control the device after setting the IP address of the destination device and the communication establishment. The motherboard is proposed as a universal module which keeps at disposal up to 6 analog outputs with the range of the control voltage 0 – 5 V and up to 21 binary inputs/outputs.
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Drainage circular machine
Dvořák, Pavel ; Mana, Jaroslav (referee) ; Kašpárek, Jaroslav (advisor)
This thesis deals with a design of a circular draining machine. The aim is to design a machine that complies with the respective requirements. The machine is assembled in a line for the preparation of paper stock, which is further processed for final paper production.
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Optimization of single slotted flap
Dvořák, Petr ; Šošovička, Róbert (referee) ; Popela, Robert (advisor)
The main objective of this diploma thesis is to optimize the high lift device on the wing of the Phoenix Air U-15 ultralight aircraft, so that it complies with the UL-2 regulation regarding the stalling speed – 65 KPH. This is fulfilled by optimization of the slotted flap position. Methods used include the Response Surface Method and the Computational Fluid Dynamics approach – namely Ansys Fluent v6 software package. Furthermore, the paper deals with take-off flap optimization and construction of the flap deflection mechanism.
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