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Acoustic properties of road markings
Drnovský, Ondřej ; Caudr, Michal (referee) ; Radimský, Michal (advisor)
The thesis deals with verifying the acoustic properties of road markings in real conditions the vehicle travels. It contains basic information about the acoustics of the sources of traffic noise and methods of measuring noise. Below are the main information about the horizontal signposts and its impact on safety. The practical part contains descriptions of results, estimation of measurement and subsequently implemented economic assessment.
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Virtual Prototypes of Drivelines
Janoušek, Michal ; Dundálek, Radim (referee) ; Slimařík,, Dušan (referee) ; Píštěk, Václav (advisor)
The thesis deals with computational modelling of heavy duty off-road vehicle driveline components. The thesis is divided to two main parts. The first part deals about modal analysis of selected driveline components. MBS computational study was performed based on modal analysis results. The second part of thesis deals with experimental verification of computational model. Pass-by noise and vibration measurement was performed. Measured signals were processed in frequency domain to find noise and vibration sources.
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Hlukové emise v chovu skotu
BLAŽEK, Petr
In my bachelor´s work I deal with the sources of noise in cattle breeding, noise emissions, welfare of animals and noise measurement. The first, the theoretical part focuses on the sound, noise and its sources, then on the cattle housing and its welfare. The second part, the practical one I focuse on the noise measuring of two choosen objects of cattle breeding, particularly dairy farming and processing of measurement results and comparison of the measured objects.
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Noise Analysis of Audio Signals
Kabarová, Anísa ; Mach, Václav (referee) ; Schimmel, Jiří (advisor)
The theoretical part of this work deals with the basics of acoustics, noise measurement and statistical noise level analysis. The application part focuses on the implementation of the frequency and time weighting according to the technical standard IEC 61672 and the statistical noise level analysis in MATLAB programming environment. Finally the reliability of the application is tested on real data and the results are compared to those measured by a digital Sound Level Meter.
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Automation of Noise Measurements Using XL2 Sounl Level Meter
Švihálek, Filip ; Číž, Radim (referee) ; Schimmel, Jiří (advisor)
This bachelor´s thesis focuses on noise measurement, characterizes used quantities and uncertainties due to the measument of these quantities. The goal is to develop application, which will automate measurement with sound level meter XL2. Automation will use text output of the XL2 and modul for Remote Measurement. Application is developed in development environment Visual Basic for Applications.
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Legislative Regulations for Vehicle Exterior Noise
Koštuřík, Vojtěch ; Prokop, Aleš (referee) ; Janoušek, Michal (advisor)
This bachelor´s thesis deals with an overview of legislative regulations for vehicle exterior noise. Introduction is dedicated to acoustics and basic acoustic variables. Next, there are mentioned sources of external noise of vehicles and distribution vehicles by category. The following provides an overview of standards and legislative documents dealing with external noise of motor vehicles. These standards and documents also establish a methodology for measuring external noise, referred to in the following chapter. In the end, there is an assessment of development of legislation in the field of external noise.
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The Noise Spectroscopy of Radiation Detectors Based on the CdTe
Zajaček, Jiří ; Štourač, Ladislav (referee) ; Hájek, Karel (referee) ; Grmela, Lubomír (advisor)
The main object of this work is noise spectroscopy of CdTe radiation detectors (-rays and X–rays) and CdTe samples. The study of stochastic phenomenon and tracing redundant low-frequency noise in semiconductor materials require long-term measurements in time domain and evaluate suitable power spectral densities (PSD) with logarithmic divided frequency axes. We have used the means of time-frequency analysis derived from the discrete wavelet transform (DWT) and we have designed the effective algorithm for PSD estimation, which is comparable with an original analog method. CdTe single crystal with Au contacts we can imagine as a series connection of two Schottky diodes with a resistor between them. The bulk resistance at constant temperature and other constant parameters changes due to the carrier concentration changing only. The p-type CdTe sample shows metal behavior with every temperature changes. Semiconductor properties of the sample begin to dominate just after some period of time. This behavior is caused by the hole mobility changing. The voltage noise spectral density of 1/f noise depends on the quantity of free carriers in the sample. All the studied samples have very high value of low frequency noise, much higher than it should have been according to Hooge’s formula. The excess value of low frequency noise is caused by the low carrier concentration within the depleted region.
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Sound level meter for embedded systems
Stejskal, Tomáš ; Schimmel, Jiří (referee) ; Botta, Miroslav (advisor)
The aim of this work is the design and implementation of a sound level meter for emdedded systems. It is designed sound level meter sensor. This sensor includes a microphone, microphone preamplifier and ADC. This sensor is connected to a development kit STM32F4 Discovery, where sound is processed. It is processed filtration, time weighting, calculation of sound leve and loudness weighting. The sound level is then sent via the serial communication USART. This thesis includes a theoretical analysis of noise and its human perceptions. It also describes the development platform used.
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Application of Acoustic Camera in Automotive Industry
Zicha, Marek ; Prokop, Aleš (referee) ; Janoušek, Michal (advisor)
This bachelor´s thesis “Application of Acoustic Camera in Automotive Industry” is focused on description of parts of the camera, algorithms for signal evaluation and the range of appli-cations in the automotive industry. They are also important acoustic quantities discussed and they are given sound fields in which the measurement is carried out.
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Noise impact of combustion engine exhaust systems
Ptáček, Petr ; Knotek, Jiří (referee) ; Zubík, Martin (advisor)
This bachelor’s thesis is focused on creating a research study about noise of combustion engine exhaust systems. Introducing of this work coves all parts of common exhaust systems while mostly focused on silencers. It further describes several methods of measuring the noise established by legislation and at its end it deals with a noise impact of exhaust system treatments.
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