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Vibrodiagnostics of electrical machines
Petráček, Samuel ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This bachelor's thesis deals with getting to know vibrations and their description. What types of vibrations occur, what are their parameters, such as deflection or acceleration, and a slightly described frequency analysis for non-harmonic signals. Subsequently, the sources of vibrations in electric rotating machines are described. Types of vibration sources are described here, for example of mechanical origin or on the bearing. The causes of their occurrence are, for example, rotor imbalance, rotor misalignment or mechanical loosening. And their subsequent effect on the machine in axial and radial directions. Furthermore, the Crest Factor measurement method and a summary of other diagnostic methods of vibrodiagnostics such as Envelope Analysis and Kurtosis Factor are described. For what purposes these methods are used and their advantages and disadvantages. In the practical part, 4 asynchronous motors were measured with prerequisites for faults with rotor eccentricity. The effective values of the vibrations and the Crest Factor were calculated here, followed by a frequency analysis using FFT (Fast Fourier Transform). In the end, the resulting data were evaluated.
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JavaME Group SMS Messaging Interface
Kubina, Tomáš ; Kubánková, Anna (referee) ; Kovář, Petr (advisor)
This Diploma Thesis have been describing possibilities of Wireless Messaging API, which are used for applications handling with Short Messages. It have been describing basics of programming language JavaME, basics of formating and sending SMS, detailed analysis of Wireless Messaging API, application, which is part of my diploma thesis and finally Security Politics of JavaME programming language.
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Monitoring of hydraulic machines using acoustic emissions
Závorka, Dalibor ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The goal of this diploma thesis is to clarify possibilities of usage of acoustic emission as a hydraulic machinery diagnostics tool. Especially for exposing presence of ruptures or cracks in the parts of machine, assuming changes in acoustic exposure of the part during operation. This clarification is based on series of simple measured experiments, which consist of monitoring the bolt placed in fluid stream inside of a pipe. This bolt was preloaded against inner wall of pipe by appropriate tightening torque. This preload is supposed to simulate effects of the size of rupture. High preload simulates small rupture or none in object and respectively small preload is supposed to simulate big rupture. A group of pressure sensors and accelerometers measures experiments and their evaluations are processed by script created in software MATLAB. Outputs of this script are charts with effective values of respective sensors from the entire record split into individual frequency spectrums. These charts compare spectrums of each configuration to judge effects of parameters changes.
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USB miltimeter with microprocessor
Samek, Martin ; Kolka, Zdeněk (referee) ; Kovář, Jan (advisor)
Topic of my terminal labour is a proposion of multimeter and its resulting connection by the help of bus USB. When proposing the multimeter there was a tendency to use a minimal number of component parts to conserve a good protection against a bad usage in application. The most widespread busbar USB is used for connection of the multimeter and a computer. Standard HID is used for communication, for that it is not neccessary to install any system drivers.
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Vibration of rolling bearing
Otoupalík, Jan ; Ripel, Tomáš (referee) ; Krejsa, Jiří (advisor)
The thesis deals with vibrations caused by geometric defect and fatigue damage of rolling element bearing. Hardware for vibration measurement is tested on 25 new pieces of NJ 304. Second part of the thesis examines if measuring of bearing vibration can help to detect a geometric defect. Geometric defects are detected according to a spectrum of vibration but the results are not absolutely exact. The possibility to detect geometric defects by measuring vibration has not been proven. The end of project tests diagnostic methods for rolling element bearings. The bearing defect was simulated to demonstrate bearing failure frequencies, envelope method and vibration spectrum.
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Vamp Plugin for Sonic Visualiser
Pilát, Peter ; Zvončák, Vojtěch (referee) ; Kiska, Tomáš (advisor)
In my Bachelor Thesis, I devote myself to obtaining information from music, the way it can be obtained, the aspect of musical information, and the use of the methods themselves. Then I analyze content-oriented music management methods and also include parameterisation of music recordings and audio signal overall. After familiarizing with the specific parameterization tools to implement the Vamp plugin, which are Sonic Visualiser and Sonic Anotator, I characterize the Vamp Plugin and explain in detail its composition. As explained in the manuals and the calculations in progress, the RMS calculation function of the given signal with the possibility of segmentation functions as well as the function of displaying the sound rate or possible changes in the track temperature. Last but not least, we mention the possible use of these supplements in the future and in different sectors.
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Card Game Maryáš For Mobile Devices
Pumprla, Tomáš ; Rychnovský, Lukáš (referee) ; Křivka, Zbyněk (advisor)
This thesis deals with development of application for mobile phones programmed in Java - J2ME. The application is a card game Marias. User can choose play with two other people or with computer which is managed by expert system. This expert system is able to updade its "knowledgebase" via HTTP communication.
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Digital Audio Signal Feature Extraction and Modification in Dynamic Plane
Kramoliš, Ondřej ; Sysel, Petr (referee) ; Schimmel, Jiří (advisor)
This thesis deals with basic methods of root mean square and peak value measurement of a digital acoustic signal, algotithms to measure audio programme loudness and true-peak audio level according to recommendation ITU-R BS.1770-1 and digital systems for control of signal dynamic range. It shows achieved results of root mean square and peak value measurement and results of implementation of dynamic processor with general piecewise linear non-decreasing static curve and algorithms according to recommendation ITU-R BS.1770-1.
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Universal mobile communication platform using the bluetooth technology
Sopko, Richard ; Šilhavý, Pavel (referee) ; Daněček, Vít (advisor)
This master’s thesis is focused on field of communication technologies in mobile devices in personal WPAN type wireless networks. Work consists of three basic parts. First part provides overview of personal WPAN wireless networks and is specialized on Bluetooth technologies and its opportunities of communication between mobile devices. Second part deals with an opportunity of using programming language Java 2 Micro Edition in work with Bluetooth technology. Key point of this work is third part which includes scheme of conception of a communication platform and creating of application designed for mobile phones. Created application enables communication by means of changing files and written conversation of two or more people in real time by Bluetooth connection.
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Sudoku for Mobile Phone
Pumprla, Ondřej ; Schwarz, Petr (referee) ; Szőke, Igor (advisor)
This thesis deals with development of application for mobile phones programmed in Java - J2ME. The application is a game Sudoku. User can solve automaticaly or manualy generate Sudoku puzzle or import a Sudoku from a web application. The web application is programmed by using PHP and MySQL. The generator makes Sudoku puzzles which are solvable on basis of common used human-solvable techniques.
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