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Confirmation of the Performance of Thermal Shock Test Chambers
Konupka, Richard ; Šedivá, Soňa (referee) ; Beneš, Petr (advisor)
The bachelor’s thesis deals with problematics of confirmation of temperature shock chamber and methodology for its successful implementation. Theoretical part deals with brief overview of environmental test chambers used for testing temperature and humidity changes on tested samples. Bachelor’s thesis also deals with analysis of methodology for confirmation of temperature chambers according to the technical standard which will be partially used for methodology proposal of temperature shock chamber. Practical part of the thesis is gradually devoted to the measurement procedure proposal, where is discussed chosen temperature sensors and fixture of sensors in the chamber. Also proposed procedure of confirmation is shown, described measurements, calculation procedures, uncertainty estimations and at the end of the thesis are discussed results.
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Contactless temperature measurement
Závodný, Ondřej ; Bejček, Ludvík (referee) ; Beneš, Petr (advisor)
In this bachelor thesis I outlined the problems of non-contact measurement and practical verification of the basic parameters thermo camera Fluke Ti20. It is especially on the experimental measurement of the source of the reference temperature and the product to demonstrate the impact of emissivity. The aim of this work is a practical verification thermo cameras parameters, the determination of uncertainties and to explore the effects of parasitic repeated measurements. The basic part is a brief recorded history, the general relations and principles of the non-contact measurement, as well as their own use and typical parameters. In the next chapter you more acquainted with itself thermo camera, properties and basic parameters. The practical part is about the measurement itself. The main objective then was to verify the accuracy of reported thermo camera and examining the impact of emissivity.
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Flow measurement
Schoř, Zdeněk ; Boček, Petr (referee) ; Beneš, Petr (advisor)
This bachelor thesis deals with flow measurement of liquids. The first part is a theoretical analysis with an overview of the most important parameters of flow sensors, the main parasitic influences and methods for calibration of flow sensors. The second part is the design and realization of the laboratory apparatus for measuring the flow of water, which is intended for the teaching of students. The apparatus is designed to test four flow sensors using weighing reference. The result of the practical part is the measurement of the basic characteristics of the flow sensors used and comparison of the obtained values with the data from a manufacturer. Further parasitic influences are added during the measurement and is determined to what extent they affect accuracy of the measurement.
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An Extended Model of a MEMS Gyroscope: Design and Identification
Vágner, Martin ; Sopata,, Milan (referee) ; Tůma, Jiří (referee) ; Beneš, Petr (advisor)
The thesis is aimed on measurement and modeling of MEMS gyroscopes based on input-output characteristics. The first part briefs the state of the art. The second part is dedicated to measurement methodology. Critical points and sources of uncertainty are discussed and evaluated using measurements or simulations. The last part shows key characteristics of MEMS gyroscopes based on the survey of a group of different sensor types. The results have revealed significant influence of supply voltage that causes bias drift of the gyroscope and bias drift of the internal temperature sensor. The error can be comparable to temperature drift; however, this effect is not addressed in the literature. The second observed effect is temperature dependency of angle random walk. In the last part, a general model of a MEMS gyroscope is rewritten to reflect observed effects. Moreover, the structure is selected to be easily extendable and the coefficients are expressed to allow a comparison of nominal parameters of different sensors.
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Processing of Uncertain Information in Databases
Morávek, Petr ; Dvořák, Jiří (referee) ; Šeda, Miloš (advisor)
The following diploma thesis focuses on processing of uncertain information in databases. Uncertain information represents vague customer requests during laptop choice in classic shop purchasing. Effort of the work is to develop a modern e-shop application selling laptops, which is based on expert fuzzy system helping customers to choose a laptop without knowledge of technical specifications and current trends.
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Confirmation of temperature chamber and determination of measurement uncertainty
Beníšek, Ondřej ; Šindelář, Michal (referee) ; Šedivá, Soňa (advisor)
The master's thesis deals with the confirmation of temperature chambers, with the greatest emphasis on the determination of standard measurement uncertainty, both by the classical method (GUM) and the Monte Carlo method. It includes the design of a measuring system with data transfer to a computer using the USB communication interface and an analysis of the sources of uncertainty entering the system, which are then practically quantified. To obtain the data, a measuring experiment was carried out in the CVVOZE testing laboratory. The LabView program was used for virtual instrumentation, in which a measuring application was designed and created, which takes care of the collection and processing of measured data. The result of the application is, in addition to recording temperatures from all measured points in the chamber, also the standard uncertainty calculated by the GUM and Monte Carlo methods, including plotting a histogram from the results obtained by both methods in order to compare them. Finally, the achieved results are compared and evaluated.
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Determination of measurement uncertainties of holes in steel components by X-ray computed tomography
Blažek, Pavel ; Šperka,, Jiří (referee) ; Kalasová, Dominika (advisor)
This thesis deals with determination of uncertainties of dimensional measurements in X-ray computed tomography. CT measurement process involves a lot of steps and is affected by a lot of factors, which depend not only on the CT system parameters but also on the measured sample and the operator. All of this influences the resulting uncertainty. Experimental method involving calibrated workpieces allows to determine the uncertainty without perfect knowledge of the influence factors. This method is described in standards ISO 15530-3 and VDI/VDE 2630 2.1. The aim of this work is to experimentally determine the uncertainty of tomographic measurement of dimensions of holes of selected workpiece on a CT device GE phoenix v|tome|x L240. Hence, a demonstration workpiece has been designed and manufactured. The dimensional CT measurements of inner and outer diameters have been performed on this sample. The reference measurement has been performed using a length measuring machine SIP 1002. The uncertainty of measurement depending on penetration thickness of the material has been determined.
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Expressing uncertainty of efficiency value
Kňava, Miroslav ; Pernikář, Jiří (referee) ; Koška, Petr (advisor)
The aim of this work is to analyze the methodology for executing examination heat transfer tubes of steam generator by method of eddy currents on EDU, to create the model for the estimate of standard combined uncertainty of efficiency value, quantify the individual components of standard uncertainties, analyse the influence of different components on the expressing of uncertainty, to make the final estimate of standard combined and enlarged uncertainty of efficiency value and as of minor objective to evaluate the suitability of the use of this method .
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The Impact of Uncertainty of Project Models on Investment Decision Making
Pískatá, Petra ; Heralová,, Renáta Schneiderová - (referee) ; Pavelková,, Martina (referee) ; Hromádka, Vít (referee) ; Heralová,, Renáta Schneiderová (referee) ; Korytárová, Jana (advisor)
This doctoral thesis widely analyses the process of investment decision-making. In its individual parts, it researches models used for planning, analysing and evaluation of investments projects, but also models used for final decision about realization of the investment. Investing activity is present in world economic cycle in all it’s phases. Capital sources used for financing if the investment projects are scarce and must be handled with care. For this reason, there are many supportive methodologies and models employed in managing of the investments as well as instruments developed to miti-gate the potential project risks. However, even utilization of these instruments and models can’t guarantee the expected results. There are uncertainties, errors and in-accuracies in the process that can thwart investment decisions. The aim of the thesis is to analyse the investment decision-making process (from the initial idea to the realization of the investment project) and to identify the main un-certainties – factors influencing the success / error rate of models for investment project planning as well as the decision on their realization. The main outcome of the thesis is an overview of these factors and recommenda-tions on how to work with these factors and make the process as effective as possi-ble. Another output is an analysis and recommendations for the use of financing sources and mix of the instruments that should be used to mitigate the potential impact of risks that are connected to all investment projects.
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