|
|
Software Sound Level Meter
Menšík, Václav ; Sysel, Petr (referee) ; Schimmel, Jiří (advisor)
This thesis discusses noise measurement devices, design and implementation of a software sound pressure meter. Sound pressure meter requirements specified by the IEC 61672 standard and selected acoustic physical properties are discussed. Further, the JUCE framework is presented along with an of the graphical user interface and digital signal processing capabilities of the SoundMeter program.
|
|
|
Software sound level meter
Kotalík, Milan ; Říha, Kamil (referee) ; Sysel, Petr (advisor)
V této závěrečné práci se zaobírám problematikou měření hluků. Popisuji lidské vnímání zvuku a vysvětluji základní parametry a veličiny zvuku podle normy ČSN EN 61672-1. Dále se zaobírám problematikou měření zvukových veličin v reálném čase. Vytvářím ucelený soubor funkcí pro měření hladin zvuku v prostředí MATLAB, které se pokouším implementovat v jazyce C++ pomocí jeho JUCE framework.
|
|
|
Analysis of the effect of friction modifiers composition on adhesion and noise in rail transport
Suchomel, Ondřej ; Galas, Radovan (referee) ; Klapka, Milan (advisor)
The aim of this bachelor thesis is experimental study of influence of composition of water based friction modifier on adhesion and sound pressure level. Experiments are carried out on twin-disk device. Introductory experiments are conducted to determine the conditions for further experiments. The experiments of the individual components follow, and the various friction modifier compositions are tested. From the results, it is obvious that a significant influence on the reduction of adhesion coefficient and sound pressure level has solid lubricant.
|
|
|
Vliv komunální techniky na životní prostředí
VOZÁBAL, Václav
This bachelor work is focused on communal technology from the perspective of its impact on environment and noise pollution. Communal technology is in this case understood as brush cutter, drum chipper and riding mower. The primary aim of this work is the practical measurement of the noise in different locations. In this bachelor work, I focused on the choice of stations, which were suitable for measuring of the noise and also for the measuring near the source of the noise. After the detailed measurement of the noise, I subsequently carried out the calculation of the equivalent level of the noise, the lowest and the highest acoustic pressure. All the data, which I gained, are transferred to graphs and tables. The final values are compared to hygienic limits of the sheltered exterior areas and evaluated according to the valid legislation.
|
|
|
Acoustics of small fans
Hájková, Lenka ; Rubina, Aleš (referee) ; Cifrinec, Ivan (referee) ; Hirš, Jiří (advisor)
Dissertation thesis falls within area of indoor climate and deals with investigation of acoustic microclimate in sanitary rooms of residential buildings during a mechanical ventilation. Sources of a noise in these areas are small fans. The thesis contains the evaluation of the existing situation concerning the referred issue, physical laws of acoustics and theoretical basics of acoustics of air conditioning. The part of the thesis is experimental measurement which aims to evaluate the situation in real applications and the possibility of influencing the acoustic microclimate by affixing of small fans on the building structure. The work contains a model for the verification of certain anticipated dependencies and theoretical investigation of the distribution of sound pressure levels in the sanitary room, depending on the location of the noise source. The last part of the work offers possible measures to improve the acoustic microclimate and elimination of the noise in sanitary rooms and in protected areas of residential buildings.
|
|
|
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.
|
|
|
Automated Processing of Acoustic Measurements
Kaláb, Vojtěch ; Kurc, David (referee) ; Schimmel, Jiří (advisor)
The goal of the Semestral thesis is to develop and describe application for automatized processing of the outputs from sound level meter NTi XL2. Application is developed in Integrated Development Enviroment Visual Basic for Application and realized in Microsoft Excel. It evaluates various types of outputs, processes its results and display the measurement protocol, including graphs of selected variables and measurement uncertainty. Theoretical part is focused on electroacustics required for understanding and processing measurement.
|
|
|
Evaluation and modelling of Traffic Noise
Černoch, Adam ; Spies, Karel (referee) ; Kudrna, Jan (advisor)
The task of the master's thesis is introduction with the problems of traffic noise, focusing on noise from road traffic. There is a description what is the noise, how it is formed, its resources and what are the methods of measuring. The following are the various noise reduction measures such as noise barriers and low noise pavements. The main attention is devoted to the noise generated at the tire / road that is reduced by these pavements. The practical part describes the implemented measurements on individual sections at various locations in our country. The measurement was carried by slightly modified method CPX with reference tire directly at the vehicle. The main aim was to evaluate the measurement data, make comparison of different low-noise surfaces with each other and with the commonly used surfaces. Then quantification of the rate reduction of the noise emission for a given section and verification of input data for noise modeling. In conclusion, the obtained results are summarized and based on them were confirmed very good acoustic properties with the recommendation to continue with measurements in the future.
|
guest ::
