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Noise Reduction Methods in Automotive Design
Kubica, Petr ; Janoušek, Michal (referee) ; Prokop, Aleš (advisor)
The aim of this bachelor thesis is create a research study about noise reduction methods in automotive design. The introduction of this work deals with acoustic and the influence of noise on people. Furthermore it deals with ways of noise creation in a car and its suppression. In the end of this work there is a valorization of certain methods at noise suppression of a personal vehicle.
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NVH parameters determination of gearbox housing
Belák, Kristián ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This master’s thesis deals with determination of NVH parameters of the gearbox housing. Introductory part is focused on the necessary theoretical knowledge. Subsequently, it contains the modal analysis with the computational and experimental approach, which are being compared to each other. In the case of the computational approach, analysis of the influence of bolt pretension on the modal properties is also involved. The thesis continues with the harmonic analysis with the computational and experimental approach, including their mutual comparison. Based on these analyses, design modifications for improvement of the NVH parameters are designed at the end of the thesis, which are being compared to each other and to the original geometry, using the computational approach.
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Neural Network Based Edge Detection
Janda, Miloš ; Žák, Pavel (referee) ; Švub, Miroslav (advisor)
Aim of this thesis is description of neural network based edge detection methods that are substitute for classic methods of detection using edge operators. First chapters generally discussed the issues of image processing, edge detection and neural networks. The objective of the main part is to show process of generating synthetic images, extracting training datasets and discussing variants of suitable topologies of neural networks for purpose of edge detection. The last part of the thesis is dedicated to evaluating and measuring accuracy values of neural network.
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NVH parameter determinantion of plate
Bouchner, Michal ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The aim of this thesis is examination and verification of numeric model for solving acoustics and vibration problems. Specifically, we are speaking about cast iron plate machined from gearbox. Main objectives of this work is set of experimental and numerical analysis at this simplified part with follow-up numerical model, where same analyses examining not only structure, but especially acoustic space around were performed. Due to this we were able to compare data between experimental and numerical analyses and to be able to prove or disprove functionality and limitation of numerical model.
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Design of modern speaker body with usage of new technology
Kůst, Martin ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis deals with the analysis and design optimization of a speaker cabinet (enclosure) produced by the additive technology of 3D sand printing. The introductory part is devoted to the theory, both in the field of noise, vibration and the method of their calculations, as well as the theory of speakers and their systems. Numerical and experimental modal analysis is performed, which were compared to determine the mechanical properties of the new material, including material damping. This is followed by experimental and numerical harmonic analysis, with output in the form of a numerical model describing the behaviour of the structure during its excitation. The data are compared with a modal analysis of the internal acoustic space and the critical shapes and their frequencies are determined. At the end of the work, construction modifications are proposed to increase the rigidity of enclosures, the influence of which is evaluated on the created numerical models.
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Utilization of light polarization when filtering the optical signal
Alexa, Jan ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
This master thesis deals with the possibility of separation of useful signal from noise using polarization of laser radiation. This thesis is structured into 5 thematic units. The first unit is focused on laser radiation and its properties. The second part contains a deeper focus on the polarization of radiation, its description and the possibilities of measuring the polarization states. The third part of the thesis is devoted to the design of the measuring chains and identification of used elements. Chapter four contains measurement of status of the polarization and its results. The last chapter analyzes particular measuring chains outputs according to their spectral characteristics.
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Low - noise pavements
Bárta, Jan ; Frýbort, David (referee) ; Hýzl, Petr (advisor)
Master´s thesis describestheproblemsoflow-noiseroadsurfaces. Thetheoretical part describestrafficnoise, sourcesofnoise, thelow-noiseroadsurfaces and thepractical part - describestwoproposalsoflow-noise stone masticasphalt SMA 8 LA and Düsseldorflow-noise stone asphalt LOA 5.
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Vibration Propagation Analysis of Coupled Structure Acoustic Space
Kostelník, Jan ; Pellant, Karel (referee) ; Novotný, Pavel (advisor)
The aim of this Master’s thesis Vibration Propagation Analysis of Coupled Structure Acoustic Space is to analyze vibration propagation in combustion engine, from combustion space through solid structure to fluid surroundings. Then analyze the noise increase as pressure changing in fluid space around the solid structure. There was made a analyze of single piston engine in different frequency and piston location. A simulation of distribution of a pressure waves was made in an ANSYS application.
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Proposal of Measures to Reduce Noise of Roots Blower
Fučík, Ondřej ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
The Master‘s thesis deals with issues of noise and vibrations of Roots blowers. In the theoretical part, potential sources of noise and vibrations are described. Detailed knowledge of basic types of mufflers is summarized, and their suitability for the corresponding application is evaluated. The practical part is focused on performing experimental measurements of the Roots blower’s noise and vibrations and the main sources of noise are determined. Subsequently, the existing anti-noise measures are analyzed and the proposal for adjusting the current measures for further noise reduction is presented.
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Multimedia support of the course BSIS
Pasečný, Jan ; Šebesta, Vladimír (referee) ; Sigmund, Milan (advisor)
This paper takes aim at creating a consistent form of study materials, supplemented with illustrative examples, for Signals and systems subject. The thesis starts with basic characteristics of acoustic, image, biological and communication signals. Characteristics of linear signals and AD&DA conversion has been added to the next part and to complete the submission, discrete signals follow. Diploma thesis as a whole contains basic theoretical description of problematics, which it tries to supplement with interesting examples, connections, graphs and matlab scripts for illustrative presentation of mentioned problematics.
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