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Noise form rolling stock in Brno
Dolíhal, František ; Dočkal, Aleš (referee) ; Klapka, Milan (advisor)
This study is focused on the analysis of data from long-term noise measurements of trams at the turning loop in Brno-Komín, and at the Technological Park turning loop in Brno. Automated field measurement based on sound pressure level and frequency evaluated tram passages to determine if there was the occurrence of squealing noise while traversing tightly curved track segments. Concurrent with noise measurements, meteorological conditions (temperature, relative humidity, and rain) were recorded. Alongside data from the preceding switch memory, including vehicle identification numbers and inspection data provided by the Brno Public Transit Company, an analysis of influencing factors on the occurrence and parameters of squealing noise was conducted. A weak dependence on air humidity (and consequently temperature) was found. This revealed varied noise behavior among tramcars of the same construction. Influence of water in contact of wheel was described during process of drying tracks. Manual field measurements also suggest the influence of vehicle speed. Observations also indicate the need for future assessment of the driver's influence and overall driving dynamics (especially acceleration), which this study does not address.
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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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Analysis of differences in biomechanical parameters during training of football players on natural or artificial grass
Malata, Mirek ; Korvas, Pavel (referee) ; Pavelka, Jan (advisor)
The aim of this bachelor thesis is to compare sprint speed and rapid change of direction on natural and artificial turf in soccer players and to verify whether higher speed is associated with a greater risk of injury. The theoretical part describes the historika development of football with its rules, the training process, the biomechanics of running, and its variation in sprinting and agility. It also focuses on describing and exploring the connections associated with natural and artificial turf in football. In the practical part, two standardized tests, the 30-meter sprint and the 5-0-5 agility test, are used to determine on which surface an athlete is faster.
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Prelouc - Hermanuv Mestec Track Speed Increase
Prikner, David ; Javořík,, Tomáš (referee) ; Dušek, Erik (advisor)
The bachelor's thesis focuses on increasing the track speed in the section of the Přelouč - Heřmanův Městec railway line. The thesis includes an analysis of the track geometry and proposes several variants to enhance the track speed by the track geometry optimisation. The individual variants are compared, and alternative methods to reduce the travel time and improve the line section attractiveness are examined.
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Perception of oncoming vehicle speed
Pršeš, Faruk ; Rak, Martin (referee) ; Bilík, Martin (advisor)
The presented master thesis deals with perception of oncoming vehicle speed. The theoretical part defines basic terminology, types, and categories of motor vehicles. Furthermore, it establishes what effects sensory perception has on estimation of vehicle speed. The practical part focuses on the examination of the measured estimations of moving vehicle where the respondents are seated and the estimations of oncoming vehicle speed according to age, gender, driver’s experience, and type of vehicle. The design, preparation and realization of the experimental measurement is in this part of the thesis. Afterwards, it is followed by an evaluation of the measured data, which gives us a better idea of how precise the witness estimations are at the traffic accident.
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Perception of vehicle speed
Hlavinková, Petra ; Dadák, Leo (referee) ; Bilík, Martin (advisor)
The presented master thesis deals with the perception of the speed vehicle crew (not the drivers) in traffic in terms of different aspects, that influencing the feeling while driving in the vehicle. This is primarily about the approximation of factors that may have an impact on the speed. The aim of the thesis is to propose an appropriate methodology of measurement and subsequent evaluation of acquired date, which leads to an improvement in the idea of whether witnesses of traffic accidents are indicative of the speed of the vehicles, at reasonable real speed.
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Analysis of the Speed of Cyclists Aged from 10 to 15 Years
Valentová, Hana ; Semela, Marek (referee) ; Bradáč, Albert (advisor)
The thesis is concerned with an analysis of speed of bicyclists in age between 10 and 15 years. The thesis examines differences in construction of children's bikes, describes relationship between a child and a bicycle, messures size of children's bikes and characterizes the procedure during an analysis of bike accidents. Internal parts of the thesis are statistical data from accident frequency and summarizing of actual state of understanding of following problems in this age category. The main purpose of this thesis is to make an analysis of speed for individual age categories and make an evaluation of results. This measurement will be completed by a measure of achievable brake deceleration of riders in age between 10 and 15 years. The purpose of this final thesis is an expansion of data for a forensic expertise in area of Traffic.
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Train Speed on the Selected Line Section
Horák, Matouš ; Hoza, Miroslav (referee) ; Svoboda, Richard (advisor)
The bachelor's thesis is engaged in finfing out speed of trains in particular section of the railway track. The first part describes a direct method of measure „in situ“ and processing the data acquired this way. The second part describes the other way, namely modeling in programme OpenTrack, then follows comparison the results from this similation with real measured values.
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Realization of educational problem based on experimental apparatus with cam mechanism
Tomeček, Vojtěch ; Vrbka, Martin (referee) ; Vaverka, Michal (advisor)
Bachelor's thesis is focused on solving educational problem based on experimental apparatus with cam mechanism. The task of the educational problem is to teach students to analyse kinematic quantities of cam followers. The thesis contains general discourse on the topic of cam mechanisms and basic terms definition. This is followed by putting the device into service, eliminating its particular imperfections, analysis of kinematic quantities of various combinations of available cams and followers and definition of methodics of the educational problem. The educational problem itself follows the presentation and commentary of gained results. At last some recommendations for the future modifications of the experimental apparatus are given followed by foreshadow of its eventual future usage.
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