|
|
Transmission line loudspeaker enclosure property measurement
Pavlik, Miroslav ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
The aim of the master thesis is to describe the characteristics of transmission line loudspeakers. Getting to know the modular transmission line enclosure, which allows changing the position of the speaker and also the combination of two mid-bass speakers. Another goal is the study of types of measurements of frequency characteristics and the subsequent processing of the procedure of composing frequency characteristics in the free field. One of the main points of the diploma thesis is the demonstration of individual properties of the enclosure using frequency characteristics. The last point is the creation of a laboratory assignment.
|
|
|
Noise study of heat pump
Gregorovičová, Eva ; Hejčík, Jiří (referee) ; Jedelský, Jan (advisor)
The thesis deals with a noise study of a heat pump, which is important for the assessment of the acoustic comfort of people. The thesis describes the theory of basic terms, quantities, measuring devices and the chosen method of determining sound power. The acoustic properties and technical condition of the measured heat pump, its possible noise sources and the possibilities of reducing their emissions are also described. The total noise level of the device is determined by the intensity probe according to the scanning method according to ČSN ISO 9614-2. Based on the acoustic map and frequency spectrum, the partial noise sources of the heat pump are identified. The resulting values from the measurements are compared with the manufacturer's values. The noise situation is assessed by measuring and comparing the measured values with the hygienic limits. Furthermore, the designs of the noise protection measures are assessed, and the design of the noise protection measures for the specific case is carried out. Finally, possible noise protection measures are implemented and experimentally verified. The results confirm the need for further development of heat pumps to reduce noise emissions.
|
|
|
Hlučnost dřevoobráběcích strojů
Junga, Petr
Thesis deal with problem of woodworking machines noise. First part work is theoretical and there are generally defined fundamental terms from theoretic acoustics area and further their applications in the woodworking industry. The second part is focused on experimental measurement of acoustic pressure emitted by chosen woodworking machines in real conditions of school workshop. There are defined methodology of the measurement by relevant international standards and valuating of measured values. The values are statistically valuated and interpreted. The conclusion summarizes main facts from measurements of acoustic pressure at working positions in specific conditions of woodworking industrial plant.
|
|
|
Pracovní podmínky obsluhy v kabinách traktorů s odlišnou výkonností při orbě.
REITMAJER, Jan
In this work is described problematic of tractor cab development and their construction. Then was described noise and performance distribution of tractors. In the practical part was monitored noise exposure in the driving area of the tractor during the plowing. For measurements were selected tractor types: New Holland T8040, Fendt 716 Vario, Case Puma 240, New Holland T7050, John Deere 8530 and Kirovec K-701. Chosen tractor types were different in performance, age and vendor. Measurement was performed in the length of one working shift, i.e. eight hours of recording data in the memory of recording device.
|
|
|
Creating a computational model of the human vocal tract
Freiwald, Michal ; Hájek, Petr (referee) ; Švancara, Pavel (advisor)
The research part of this bachelor’s thesis consists of a brief introduction to the human respiratory system and its subsidiary vocal subsystem along with a summary of basic phonation theories, voice disorders and published computational models of the human vocal tract. The experimental part engages in the making of the computational model itself, set to pronunciation of the vowel /a:/ in a woman vocal tract, on which, using finite element method, some of the basic acoustic analyses are performed, such as modal analysis or harmonic analysis. Calculated formants correspond with the values published in literature. Several different methods were analyzed while computing harmonic response. The most complex and the most time-consuming method, using infinite elements, also proved to be the most precise one. Thesis gives a decent comparison of the precision and complexity between the used methods.
|
|
|
Hluková analýza v chovu dojnic ve vybraném podniku
DOBROVOLNÝ, Tomáš
In this bachelor thesis, especially in the theoretical part I focus on the construction of stalls and the technologies used in the dairy cows breeding. The next solved topic is welfare so as the last theme is the noise and its sources in the animal husbandries. The practical is focused on the description of the monitored stall unit. The noise level LpA measurement was done under the cattle load with the technological operations by the chosen dairy cows were observed in the workplaces of the agricultural cooperative in Velká Losenice. The results of measurements and comparisons in the chosen objects are introduced in the conclusion of this bachelor thesis.
|
|
|
Problematika dopravního hluku.
KOLÁŘ, Jiří
This thesis deals with the issue of noise produced by road traffic in six selected areas of south bohemian communities Budweis and Třeboň. In all six areas the measurements were carried out according to the approved methodology and the results were compared with already known data measured from these locations. The results were compared with relevant legislations and standards, and possible measures were proposed in order to reduce the exposed values.
|
|
| |
|
|
Determination of sound power levels of heating equipment by measurement of the acoustic intensity
Wagnerová, Klára ; Doložílek, Miroslav (referee) ; Jedelský, Jan (advisor)
This thesis concerns method of determining sound power level of heating devices from acoustic intensity as a primary measured value. Thesis describes the characteristics of acoustic parameters and principles of acoustic measuring. Method of measurement at discret points according to ČSN EN ISO 9614-1 is compared with measurement by scanning according to ČSN ISO 9614-2. Methods are evaluated teoreticly as well as practically by companing results of experimental testing. Thesis also includes description of created model which evaluates acoustic measurement acording to the definitionof point method. The model is designed for measuring chain of Engineering Test Institute, Public Enterprise (SZU).
|
|
| |
guest ::
