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Comparison of vowel formants with string and wind instrument formants
Steiner, Dominik ; Musil, Jaroslav (referee) ; Jirásek, Ondřej (advisor)
This thesis deals with the analysis and subsequent comparison of the formant regions of sung vowels of different singing voices with the formants of string and musical instruments based on FFT and LPC analysis. The results of the work are primarily intended for musicians and arrangers for compositional and musical artistic purposes. However, it will also help linguists regarding the analysis of formants and resonant cavities for phonetic and phonological research.
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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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Computational Modelling of the Automotive Gearbox Dynamics Using Multi-Body Approach
Suchý, Pavel ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
The thesis deals with construction of a computational model of the manual automotive gearbox MQ281 in MSC ADAMS View software, on which several static and dynamic operating states of the gearbox are simulated. The input for the MBS model construction is the CAD assembly of the gearbox in necessary detail and parameters of all gears. The computational model uses a custom model of bearings and the engagement helical spur gears based on the transmission error. The outputs of the simulations are courses of forces and moments acting in bearings, gears and synchronizing clutches, courses of shafts deflection, courses of angular velocities of shafts and gears, frequency analysis of operating states.
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Automation of the calibration process
Mařas, Michael ; Šedivá, Soňa (referee) ; Beneš, Petr (advisor)
This master thesis deals with the automation of the calibration process at the workplace for calibration of electronic power meters and the description of the method of evaluation of calibration results. The paper analyses the calibration workstation and the manual method of calibration performed by the calibration laboratory staff. Furthermore, proposals for automating the manual method of calibration and a description of the implementation of a program for automating this process are given. Subsequently, the uncertainty analysis is described in the paper. In this section, the uncertainty analysis according to the GUM method and the subsequent calculation of these uncertainties are presented. The correctness of the calculation of uncertainties according to the GUM method is verified by the Monte Carlo method. In the last part of the work, the method of evaluation of the calibration results according to ILAC-G8:09/2019 is described and the form of the calibration protocol is described.
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Possibility of using EMW radiation for killing biotic pests
Gintar, Jan ; Klečka,, Tomáš (referee) ; Pěnčík, Jan (referee) ; Šuhajda, Karel (advisor)
The remediation of building elements and structures in terms of moisture and sterilization (inactivation) of biotic pests is dealt with quite often in construction practice and in the construction industry itself, and is thus a topical issue. The issue is dealt with by specialized companies that know the use of available technology on the market, or are themselves involved in the development and improvement of these devices. Several methods are known for the removal of moisture and sterilization of biotic pests, with sufficiently high-quality data on the technology used, the suitability of the equipment used, a more detailed description of the application of the methods themselves and the results themselves. The methods themselves, for removing moisture and eliminating (inactivating) biotic pests, must be chosen according to individual requirements, as some methods will be more appropriate (more effective) and some less suitable. For the practice itself, however, it is important that the methods are sufficiently effective and at the same time available to the wider public (their economic side). In my dissertation thesis I focus on the potential of EMW radiation utilization not only for liquidation of biotic pests (fungi, fungi, wood decaying insects), but also elimination or reduction of necessary conditions for survival or development of these biotic pests. Therefore, my work also focuses on the presence of moisture, because moisture is a common factor in the vast majority of problems associated with the occurrence of biotic pests. Due to its intensity, it is one of the less time-consuming method and therefore a more cost-effective (economically) method. The research I conducted at VUT FAST focused on the use of microwave radiation in the control of biotic pests, under conditions that are close to those on real constructions. The use of a microwave method to eliminate biotic pests and at the same time to remove moisture has proved to be advantageous.
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The Analysis of mutes on trombone and trumpet timbre
Košař, Vojtěch ; Mojdl, Edgar (referee) ; Jirásek, Ondřej (advisor)
This work deals with the sound mute issues, specifically how they affect the timbre of a trombone and a trumpet, their sound spectrum, levels of individual harmonic tones, the presence of formants and the directional characteristics of individual tones played in various dynamics. A part of this work is also focused on the theoretical description of a trombone and a trumpet, including their brief history, their classification, the parts they are consisting of and the timbre. The theoretical part is further dealing with the description of mathematic functions like FFT or LPC analysis, which have been implemented in the MATLAB environment when creating the graphic dependents for this theme.
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Photoimpedace spectroscopy characterization of optical and electrical properties of the photovoltaic cells
Mocharová, Zuzana ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
Diploma thesis mainly describes the theoretical knowledge of the topic photoimpedance spectroscopy characterization of optical and electrical properties of the photovoltaic cells, which contains development and princip of cells working, material properties of photovoltaic cells, explanation of electromagnetic waves, spectrophotometry and impedance spectroscopy, followed by a discription of the measuring device and used measuring methods. The experimental section for each measurement method describes the steps of setting the program, then the tables with measured values are involeved in some parts and a part of each method are summary graphs of measured values with subsequent evaluation.
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Disposal of Biotic Pests by EMW Radiation
Sobotka, Jindřich ; Klečka,, Tomáš (referee) ; Myslín, Jiří (referee) ; Tomíček,, Oldřich (referee) ; Šuhajda, Karel (advisor)
The possibility of using high-frequency electromagnetic radiation in the construction sector is a common knowledge. Various experiments have been carried out to dry construction materials, or even to destroy biotic pests. However, the majority of these experiments have been executed in laboratory conditions. It means they have been carried out under exact limiting conditions, often very far off those conditions in real building practice. Therefore, this dissertation aims at exploring the possibility of utilizing microwave technology in drying and heating of construction materials, in disposing of biotic pests and sterilizing building materials under real conditions in building practice. The thesis will explain that microwaves are a term given to a part of electromagnetic radiation. Electromagnetic radiation is based on the principle that the radiated energy is absorbed by water molecules present in moist building material. In the mass of the irradiated material, the radiated energy is transformed into thermal energy, where a so-called “motion” of water molecules occurs with the energy then being transformed into kinetic energy. The microwave technology itself offers a very wide range of use, which can be easily achieved, thus making the technology available to use in the future. Part of the experiments and the necessary measurements, too, has been carried out on selected types of building materials in the premises of the Faculty of Civil Engineering of Brno University of Technology. They have been executed under conditions which most closely correspond to the conditions in real buildings. Part of the experiments and the necessary measurements were carried out on particular constructions, by the so-called in situ method. As stated in the conclusion of the dissertation, laboratory measurements and the in situ measurements differ considerably in some cases.
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Automatization of Analysis of Performance and Power Consumption
Rudolf, Tomáš ; Jaroš, Jiří (referee) ; Nikl, Vojtěch (advisor)
This thesis deals with increasing efficiency of supercomputers. Higher efficiency can be achieved by reducing frequency of processor if the algorithm does not slow down significantly. This thesis presents set of scripts designed to monitor consumption of processor along with scripts that visualize these measured values. It also allows easy control of processor frequency. The created solution gives user a capability to measure given algorithm efficiency and optimize computing power of specific computer exactly for the algorithm. Due to this work the user will be informed about whether it is advantageous to run his algorithm on one or other frequency of the processor.
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Optimalization of Induction Furnace Operation in foundry Vsetín
Trachta, Jiří ; Nowak, Stanislav (referee) ; Lázničková, Ilona (advisor)
The aim of this work is optimalisation of induction furnace in foundry for company PROMET FOUNDRY a.s. The company has two induction furnances. There are installed as identical construction. They have 2 modes of operation. First mode is founding and second mode is mode, where is temperature in maintain mode. Only one induction furnance can work in the founding mode at a time though. Inducion furnances are in the single-phase connection and they cause unbalance in the distribution network. Near the foundry there is a small network area whitch it is operated by company Zásobování teplem Vsetín a.s. The consumption of electrical energy in foundry so big, that in the year 2009 was made elaborate for Zásobování teplem Vsetín a.s. It was write at Laboratoře diagnostiky výkonů (Laboratory of performance diagnostics), which is a part of Electrotechnic Department at Technical Univarsity of Ostrava. The ordered study was named “Verification of causes of increased reactive energy consumption during transition from electricity delivery to electricity consumption”. The conclusion of this assignment confirms that in distribution network in the Jiráskova area in Vsetín there is unbalance of electrical energy and there is high part of reactive power. The next conclusion is crucial to find the customer who made the unbalance and to set relevant remedy. The last step will be the identification whether such device can actually be effectively balanced. It was subsequently proved that the Promet Foundry was causing the unbalance and that balanced consumption would be reasonable. Promet Foundry thus addressed Autel a.s. company with an inquiry to make a study of removing the causes of the unbalance which is caused by current induction furnaces operation at a minimum possible cost, least possible influence on the performance and minimum construction changes concerning the building. In this thesis there will be some topics. The result of which will be introducing of used heating technology, introducing of company and of effective plant performance and subsequent suggestions of possible unbalance removal or reactive power decrease. Several ways which are being implemented in the industry in order to balance consumption will be described. A suitable balancing plant will be subsequently chosen and its parameters will be calculated.
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