• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Quantifying Coordinate Uncertainty Fields in Coupled Spatial Measurement systems

Calkins, Joseph Matthew 06 August 2002 (has links)
Spatial coordinate measurement systems play an important role in manufacturing and certification processes. There are many types of coordinate measurement systems including electronic theodolite networks, total station systems, video photogrammetry systems, laser tracking systems, laser scanning systems, and coordinate measuring machines. Each of these systems produces coordinate measurements containing some degree of uncertainty. Often, the results from several different types of measurement systems must be combined in order to provide useful measurement results. When these measurements are combined, the resulting coordinate data set contains uncertainties that are a function of the base data sets and complex interactions between the measurement sets. ISO standards, ANSI standards, and others, require that estimates of uncertainty accompany all measurement data. This research presents methods for quantifying the uncertainty fields associated with coupled spatial measurement systems. The significant new developments and refinements presented in this dissertation are summarized as follows: 1) A geometrical representation of coordinate uncertainty fields. 2) An experimental method for characterizing instrument component uncertainty. 3) Coordinate uncertainty field computation for individual measurements systems. 4) Measurement system combination methods based on the relative uncertainty of each measurement's individual components. 5) Combined uncertainty field computation resulting from to the interdependence of the measurements for coupled measurement systems. 6) Uncertainty statements for measurement analyses such as best-fit geometrical shapes and hidden-point measurement. 7) The implementation of these methods into commercial measurement software. 8) Case studies demonstrating the practical applications of this research. The specific focus of this research is portable measurement systems. It is with these systems that uncertainty field combination issues are most prevalent. The results of this research are, however, general and therefore applicable to any instrument capable of measuring spatial coordinates. / Ph. D.
2

Vyjadřování nejistoty výsledku zkoušky / Expressing uncertainty of efficiency value

Kňava, Miroslav January 2010 (has links)
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 .
3

Určení nejistot při stanovení průtoků ve vodních tocích pomocí měření hydrometrickou vrtulí. / Evaluation Of Uncertainties Of River Flow Measurements With Propeller Current-Meter

Niemiec, Łukasz January 2013 (has links)
The development of hydrology and the need of getting exact data increase the demands on hydro metering. Measurement of spot velocities and deriving the flow of water are frequently performed by the workers of Český hydrometeorologický ústav (Czech Hydrometeorological Institute) and other companies. The limited precision of the measuring machines, the imperfection of methods and the influence of human senses cause that we are not able to get the accurate value of quantity. We are just close to the right values. The term uncertainty of measuring determines the interval which is assigned to each measurement and contains the real value of measured quantity. Twenty imminently repeated measurement were done in twelve measuring profiles of the Dyje River and in one profile of the Morava River using the current meters OTT (OTT Hydromet, 2013) type C2 and type C31. We investigated the dependence of uncertainties type A and B in different profile parameter. The measurement was done with the suspension bar with 2 to 4 propeller current-meters. The hydrometric car on the bridge was used in deeper waters. The results were analysed from the point of view of the uncertainties and generalized. Next point of the research was to find out how the frequency of the current meter depends on temperature of water. For this purpose, the specific canal was made in the Faculty of Civil Engineering in Brno (Ústav vodního hospodářství krajiny) and the measuring was done in temperature interval from 1 °C to 24 °C. Repeated measuring was statistically evaluated from the uncertainties point of view. In the thesis, the proposal of elaboration of uncertainties determined by both types of measurement into current methods of determination of uncertainties of the derived flows using the measurement of spot velocity by the propeller current-meter in measuring profiles of the rivers is introduced.
4

Aspekty spolehlivosti při posuzování shody výrobků / Aspect of reliability in compatibility evaluation of products

Šenkýř, Michal January 2008 (has links)
The diploma thesis deals with stating the aspects of reliability in product compatibility evaluation, namely with stating result uncertainty in product parameters testing and diagnosis which are imperative for introduction of the product to the market. The practical part of the thesis focuses on stating selected uncertainty in warm-water boilers testing, especially in gas fueled boilers with rated thermal input of max. 70 kW.
5

Metodika zabezpečování optimální přesnosti měření v souladu s metrologickou konfirmací / The Optimal Accuracy of Measurement Assurance in Accordance with Metrological Confirmation

Frank, Petr January 2009 (has links)
This thesis deals with the evaluation of accuracy of measurement and achieving the required accuracy level. This includes global analysis of the uncertainty evaluation, the calibration interval design and the creation of confirmation system. Basis of this work is in identification of all possible problems, which may occur during evaluation of accuracy and achieving the required accuracy level. The analysis is followed by suggested solutions for identified problems. It means namely the selection of probability distribution in case of uncertainty type A, evaluation of degrees of freedom in case of uncertainty type B, nonlinear correlation of input values, evaluation of coverage factor, the choice of method for calibration interval design and the procedure for meeting all metrological confirmation requirements. The last part of the thesis is practical measurement and result evaluation in the field of surge protection devices. This chapter demonstrates conclusions from the syntactical part.

Page generated in 0.0384 seconds