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Uncertainty of vehicle dimension measurement using 2D lidar
Želinský, David ; Richter, Miloslav (referee) ; Šedivá, Soňa (advisor)
This diploma thesis deals with the explanation of terms such as measurement error and uncertainty of measurement. It also introduces the term LiDAR, describes its construction, how it works and what it can be used for. The information from the theoretical part of this thesis is then used to analyze the uncertainties of measuring the dimensions of vehicles using 2D LiDAR. The individual measurement uncertainties are explained and calculated on an example. Furthermore, a LabVIEW program is created, which calculates the dimensions of the vehicle and the uncertainties of these dimensions from measured data. Finally, the results of the program are compared with real dimensions. The thesis is elaborated for the company Cross Zlín.
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The effect of the growth and development of the endosteal surface on the estimation of cross-sectional properties
Königová, Viktória ; Sládek, Vladimír (advisor) ; Friedl, Lukáš (referee)
Past studies concerning deriving periosteal and endosteal contours from micro-CT scans of non-adult long bones found the greatest error to stem from the automatic processing of the endosteal contours. Furthermore, with increasing age, a decrease in the estimation error of the cross-sectional properties was observed. This study aims to identify the specific source of the estimation error and to optimize the use of the automatic method of deriving endosteal contours. Four parameters (circularity, solidity, roundness, and aspect ratio) were used to quantify the shape properties of the endosteal contour. These parameters were tested on 91 individuals from birth to early adulthood. As for the ontogenic changes in the endosteal contour, a continuous decrease in the jaggedness of the endosteal contour had been observed, mainly based on the changes in the circularity. Circularity was chosen as the parameter upon which the criteria of use of the automatic method of deriving the endosteal contour was based. The criterium is based on the prediction of whether the customary threshold of 5 % percent prediction error would be surpassed while using the automatic method at a certain level of circularity. Applying the criteria of the minimum threshold of circularity (0,83 for MA, 0,71 for CA, and 0,7 for ZP) will...
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Uncertainty of vehicle dimension measurement using 2D lidar
Želinský, David ; Richter, Miloslav (referee) ; Šedivá, Soňa (advisor)
This diploma thesis deals with the explanation of terms such as measurement error and uncertainty of measurement. It also introduces the term LiDAR, describes its construction, how it works and what it can be used for. The information from the theoretical part of this thesis is then used to analyze the uncertainties of measuring the dimensions of vehicles using 2D LiDAR. The individual measurement uncertainties are explained and calculated on an example. Furthermore, a LabVIEW program is created, which calculates the dimensions of the vehicle and the uncertainties of these dimensions from measured data. Finally, the results of the program are compared with real dimensions. The thesis is elaborated for the company Cross Zlín.
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Motion of a body in a fluid with pressure dependent viscosity
Sláčík, Stanislav ; Průša, Vít (advisor) ; Süli, Endré (referee)
A lot of technologically relevant incompressible fluids exhibit a substantial variaton of viscosity with the pressure;a falling cylinder viscometer is frequently used for the measurements, determining the viscosity indirectly from the time it takes the sinker to fall a given distance. The relation between the sinker fall velocity and the fluid viscosity is, however, derived under the constant viscosity assumption. The objective of the present thesis is to perform a numerical simulation of the viscometric experiment, assuming an explicit form of the pressure-viscosity dependence and realistic parameter values and to quantitatively assess the difference in body motion to the Navier- Stokes model. The computational method proposed, handling both the nonlinear constitutive relation and the body motion, was tested on simple problems with analytical solutions. The semianalytical relation for the Navier-Stokes model, also re-derived here, is compared to the computational results.The validity of the assumptions used in the theoretical derivation, based on the results of the numerical simulation, is discussed regarding the geometry of the viscometer. Powered by TCPDF (www.tcpdf.org)
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Analytical methods for measurement error estimation in survey data
Chylíková, Johana ; Vinopal, Jiří (advisor) ; Kreidl, Martin (referee) ; Buriánek, Jiří (referee)
Analytical methods for measurement error estimation in survey data This dissertation aims at the domain of measurement error in social science survey data. To conceptualize and estimate measurement errors it employs the analytical and theoretical framework that stems from the analytical method of structural equation modeling (SEM) and Classical Test Theory (CTT), extended with the component of the systematic measurement error. This thesis has two goals that may contribute to development and extension of Czech social science methodology. The first goal is to illustrate methods of measurement error estimation, which has not been used for analysis of Czech data yet, and to point out to some problematical aspects of these methods. The second goal is to employ presented methods to obtain new findings regarding the quality of data from Czech surveys. The dissertation presents three empirical studies, each of which uses one of the methods defined within the presented theoretical and analytical framework. First study presents an analysis of reliability of measurement with the Quasi Simplex Model (QSM). It illustrates how to use the model and brings optimistic results regarding the reliability of the Czech EU SILC panel data. In the second study the confirmatory factor analysis model, operationally called...
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Detection of the measurement error using the reaction time
Antoňová, Tereza ; Remr, Jiří (advisor) ; Hendl, Jan (referee)
The diploma thesis deals with the detection of measurement error based on the question order using the reaction time. The major part of the theoretical chapter deals with the respondent as the source of the error. A respondent needs to proceed through a cognitive process to answer a question. Various influences affect the process and they might have an effect on the accuracy of the answer. The frequently mentioned effects are age, education and motivation of respondent. The absence of respondents' motivation might lead to a reduction of their effort to properly proceed with the cognitive process. In that case, the respondent does not dedicate the appropriate cognitive effort and time to a question in the questionnaire. That length of time, which the respondent takes to answer, is called the reaction time and it is suggested that it might be used as an indicator of the amount of cognitive effort. Based on previously executed studies, the author designed hypotheses about the change in length of the reaction time with a change of question position in a questionnaire, about the effect of respondents' characteristics on the reaction time and its shortening. The significant shortening of the reaction time on the question located closer to the end of the experimental questionnaire is used as an indicator...
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Determining the measurement accuracy of a coordinate measuring machine Zeiss UPMC Carat
Kiška, Roman ; Jankových, Róbert (referee) ; Šrámek, Jan (advisor)
The aim of this diploma thesis is to create a comprehensive study of measurement accuracy of coordinate measuring machine (hereinafter CMM) Zeiss UPMC 850 Carat S-ACC (hereinafter Zeiss Carat) for the needs of the national metrological institute in Brno in accordance with ČSN EN ISO / IEC 17025 and the follow-up system standards of the ČSN EN ISO 10360 series. Additionally, it includes the creation of instructions for the calculation of measurement uncertainty, which will be put into effect in an accredited calibration laboratory. The first part of the work focuses on the description of the current state of knowledge and the definition of basic concepts in the field of metrology and accurate measurements on CMM. The second part describes the Zeiss Carat measuring machine, identifies the individual contributors to the resulting measurement uncertainty and defines the methodology for their quantification. The last part deals with the evaluation of calibration data and the calculation of the expanded measurement uncertainty of the Zeiss Carat instrument, which is used to quantify its accuracy.
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Order Effect
Truong, Phuong Thi ; Remr, Jiří (advisor) ; Jeřábek, Hynek (referee)
This thesis deals with a methodological phenomenon called order effect. This effect creates a situation where the preceding questions influence answers of the subsequent questions. During cognitive responding process, the preceding questions may evoke specific mental associations and ideas that are more easily accessible afterwards during responding of the following questions. This induced information may be used during answer selection process which may cause bias in answers. The same questions placed in different order can generate different answers. Different question order can have different cognitive burden. The aim of this thesis is cognitive burden assessment of different question orders. Data collection was conducted by cognitive interviews which helped to detect how respondents work with particular questions during questionnaire responding process, and to identify specific types of order effect. There are four types of order effect: carryover effect, backfire effect, assimilation and contrast effect. A specific question preceding a general question evokes information which is more accessible for interpretation of a general question therefore this question order is less burdensome. Also the order from negative to positive question is less burdensome than the opposite order because it evokes...
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Detection of the measurement error using the reaction time
Antoňová, Tereza ; Remr, Jiří (advisor) ; Hendl, Jan (referee)
The diploma thesis deals with the detection of measurement error based on the question order using the reaction time. The major part of the theoretical chapter deals with the respondent as the source of the error. A respondent needs to proceed through a cognitive process to answer a question. Various influences affect the process and they might have an effect on the accuracy of the answer. The frequently mentioned effects are age, education and motivation of respondent. The absence of respondents' motivation might lead to a reduction of their effort to properly proceed with the cognitive process. In that case, the respondent does not dedicate the appropriate cognitive effort and time to a question in the questionnaire. That length of time, which the respondent takes to answer, is called the reaction time and it is suggested that it might be used as an indicator of the amount of cognitive effort. Based on previously executed studies, the author designed hypotheses about the change in length of the reaction time with a change of question position in a questionnaire, about the effect of respondents' characteristics on the reaction time and its shortening. The significant shortening of the reaction time on the question located closer to the end of the experimental questionnaire is used as an indicator...
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