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1
Mihaylov, Blagovest V. "Uncertainty considerations in photovoltaic measurements." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23251.
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Measurement uncertainty is an indication of the quality of a given measurement and ultimately translates into the confidence with which a decision can be made. In the context of PV, measurement uncertainties propagate into energy yield uncertainty, which in turn culminates into financial risk associated with an investment. This risk increases the cost of a PV installation. The aim of this thesis is to contribute towards the reduction of PV related measurement uncertainties. This is done in two ways. One is via developing and utilising more comprehensive methodologies for uncertainty propagation of complex measurands. The other is via more detailed estimates of the uncertainty contributors. In particular, the areas addressed in this thesis are the uncertainty estimation of the temperature coefficient measurements of modules; the uncertainty estimation of energy rating and module performance ratio measurements; and the uncertainties due to spectral effects on measurements performed with a flash solar simulator. The reported deviation in measurements of the temperature coefficients of P_MAX of modules is in the order of ±10% to ±15%. This is larger than the difference in the temperature coefficients of modules of the same type. The first step to improving the deviation between measurements is to estimate the uncertainty in a robust way. It was identified that there was no accepted approach of doing this. These measurements are strongly correlated, which complicates the uncertainty estimates. For the sake of simplicity, previously correlations have been avoided and conservative estimates used instead. In this work, uncertainties in both temperature and power and their correlations are estimated and propagated into the overall temperature coefficient uncertainty. Furthermore, temperature coefficients were calculated via weighing the measurements with their associated uncertainties. This was done for five different measurement setups that represent the majority of setups used worldwide. The approach was validated with measurement intercomparison of two modules measured on all systems. The approach reduced the overall uncertainty by half compared to the previous conservative estimates. It was demonstrated that uncertainties as low as 3% are achievable. The improved uncertainty estimates enabled the identification of a systematic effect due to a class B spectrum. This work culminated in the lowest reported measurement deviation of ±3.2% for module P_MAXtemperature coefficient measurements that was within the stated measurement uncertainties. The clear benefit of accounting for correlations was extended to measurements at different irradiance conditions and into the calculation of module performance ratio and energy rating. This was done via defining all the correlations between measurements and then propagating them with Monte Carlo simulations. The simulations are done with samples of a multivariate normal distribution with a variance-covariance matrix that corresponds to the estimated measurement correlations. It is demonstrated that both the energy rating and module performance ratio uncertainties strongly depend on the correlation estimates and that they cannot be conservatively overestimated. The module performance ratio uncertainty can be significantly lower than the measurement uncertainty at STC. This is because of the additional knowledge encoded into the selection of the underlying model used for calculating the energy rating. Therefore, the significance of the choice of model in the upcoming standard has been highlighted. It was confirmed that both bilinear interpolation and the proposed climatic datasets could be used for energy rating, but there are some areas that may need further investigation. An alternative way of improving uncertainty estimates and in turn reducing the associated uncertainty is via a more detailed characterisation of the uncertainty sources. A key uncertainty source is due to spectral effects in flash solar simulators. To better quantify this source, a complementary device was built to monitor the spectrum. The device is based on a matrix of photodiodes with commercially available interference filters situated on top and custom designed data acquisition electronics. This device is used in conjunction with the spectroradiometer to estimate the effects of flash-variation on the spectrum, the spectral temporal stability of the flash and spectral uniformity of the simulator and the attenuation masks used for altering the irradiance levels. It was demonstrated that the spectrum changes significantly during the flash and between flashes. While this effect is partially corrected for via the monitoring cell, it introduces additional uncertainty for non c-Si modules. This uncertainty is minimised by changes in the operational procedures. The spectral non-uniformity of the attenuation masks was shown to be significant, i.e. as large as 4%, in the NIR, prompting further investigation of the additional uncertainty for non c-Si modules. In this work, the methodology of estimating and propagating correlations in PV related measurements and the benefits of doing so are demonstrated. It is also highlighted that the uncertainty due to spectral effects goes beyond the uncertainty of spectroradiometer measurements. Finally, it is shown how they can be estimated with a complementary spectral monitor.
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Fawzi, Omar. "Uncertainty relations for multiple measurements with applications." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110554.
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Uncertainty relations express the fundamental incompatibility of certain observables in quantum mechanics. Far from just being puzzling constraints on our ability to know the state of a quantum system, uncertainty relations are at the heart of why some classically impossible cryptographic primitives become possible when quantum communication is allowed. This thesis is concerned with strong notions of uncertainty relations and their applications in quantum information theory.One operational manifestation of such uncertainty relations is a purely quantum effect referred to as information locking. A locking scheme can be viewed as a cryptographic protocol in which a uniformly random n-bit message is encoded in a quantum system using a classical key of size much smaller than n. Without the key, no measurement of this quantum state can extract more than a negligible amount of information about the message, in which case the message is said to be "locked". Furthermore, knowing the key, it is possible to recover, that is "unlock", the message. We give new efficient constructions of bases satisfying strong uncertainty relations leading to the first explicit construction of an informationlocking scheme. We also give several other applications of our uncertainty relations both to cryptographic and communication tasks.In addition, we define objects called QC-extractors, that can be seen as strong uncertainty relations that hold against quantum adversaries. We provide several constructions of QC-extractors, and use them to prove the security of cryptographic protocols for two-party computations based on the sole assumption that the parties' storage device is limited in transmitting quantum information. In doing so, we resolve a central question in the so-called noisy-storage model by relating security to the quantum capacity of storage devices.Les relations d'incertitude expriment l'incompatibilité de certaines observables en mécanique quantique. Les relations d'incertitude sont utiles pour comprendre pourquoi certaines primitives cryptographiques impossibles dans le monde classique deviennent possibles avec de la communication quantique. Cette thèseétudie des notions fortes de relations d'incertitude et leurs applications à la théorie de l'information quantique.Une manifestation opérationnelle de telles relations d'incertitude est un effet purement quantique appelé verrouillage d'information. Un système de verrouillage peut être considéré comme un protocole cryptographique dans lequel un message aléatoire composé de n bits est encodé dans un système quantique en utilisant une clé classique de taille beaucoup plus petite que n. Sans la clé, aucune mesure sur cet état quantique ne peut extraire plus qu'une quantité négligeable d'information sur le message, auquel cas le message est "verrouillé". Par ailleurs, connaissant la clé, il est possible de récupérer ou "déverrouiller" le message. Nous proposons de nouvelles constructions efficaces de bases vérifiant de fortes relations d'incertitude conduisant à la première construction explicite d'un système de verrouillage. Nous exposons également plusieurs autres applications de nos relations d'incertitude à des tâches cryptographiques et des tâches de communication.Nous définissons également des objets appelés QC-extracteurs, qui peuventêtre considérés comme de fortes relations d'incertitude qui tiennent contre des adversaires quantiques. Nous fournissons plusieurs constructions deQC-extracteurs, que nous utilisons pour prouver la sécurité de protocoles cryptographiques pour le calcul sécurisé à deux joueurs en supposant uniquement que la mémoire des joueurs soit limitée en ce qui concerne la transmission d'information quantique. Ce faisant, nous résolvons une question centrale dans le modèle de mémoire bruitée en mettant en relation la sécurité et la capacité quantique de la mémoire.
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Sooväli, Lilli. "Spectrophotometric measurements and their uncertainty in chemical analysis and dissociation constant measurements /." Online version, 2006. http://dspace.utlib.ee/dspace/bitstream/10062/627/5/soovalililli.pdf.
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Sozak, Ahmet. "Uncertainty Analysis Of Coordinate Measuring Machine (cmm) Measurements." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608887/index.pdf.
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In this thesis, the measurement uncertainty of Coordinate Measuring Machine
(CMM) is analysed and software is designed to simulate this. Analysis begins with
the inspection of the measurement process and structure of the CMMs. After that,
error sources are defined with respect to their effects on the measurement and then an
error model is constructed to compensate these effects. In other words, systematic
part of geometric, kinematic and thermal errors are compensated with error
modelling. Kinematic and geometric error model is specific for the structure of
CMM under inspection. Also, a common orthogonal kinematic model is formed and
with using the laser error data of the CMM and error maps of the machine volume is
obtained. Afterwards, the models are compared with each other by taking the
difference and ratio.
The definition and compensation of the systematic errors leave the uncertainty
of measurements for analysing. Measurement uncertainty consists of the
uncompensated systematic errors and random errors. The other aim of the thesis is to
quantify these uncertainties with using the different methods and to inspect the
success of these methods. Uncertainty budgeting, comparison, statistical evaluation
by designing an experiments and simulation methods are examined and applied to
the CMM under inspection. In addition, Virtual CMM software is designed to simulate the task specific measurement uncertainty of circle, sphere and plane
without using the repeated measurements. Finally, the performance of the software, highly depending on the
mathematical modelling of machine volume, is tested by using actual measurements.
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Bußhardt, Michael [Verfasser]. "Timing and uncertainty in pointer-based quantum measurements / Michael Bußhardt." München : Verlag Dr. Hut, 2011. http://d-nb.info/1015607969/34.
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SILVA, GUTEMBERG BRUNO DA. "COLORIMETRY: PROPAGATION OF ERRORS AND UNCERTAINTY CALCULATIONS IN SPECTROPHOTOMETRIC MEASUREMENTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5012@1.
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FINANCIADORA DE ESTUDOS E PROJETOSMINISTÉRIO DA CIÊNCIA E TECNOLOGIA
Colorimetria - Propagação de erros e cálculo da incerteza da medição nos resultados espectrofotométricos trata da medição da cor de objetos, baseada nas medições de irradiância espectral (objetos luminosos) ou de refletância ou transmitância espectral (objetos opacos ou transparentes), seguidas por cálculos colorimétricos conforme o sistema CIE. As medições são normalmente feitas em intervalos de 5nm (ou 10 nm) na faixa espectral de 360 a 780nm, e os três valores triestímulos (X, Y e Z) são calculados usando-se 42-84 pontos medidos por equações padrões. A distribuição dos valores medidos R(lambda) é, provavelmente, normal, com uma correlação entre os valores obtidos variável em posições diferentes do espectro. As distribuições dos valores e as correlações entre X, Y e Z são desconhecidas e dependem da forma da curva espectral da cor e do funcionamento dos instrumentos de medição. No controle instrumental das cores são usadas fórmulas muito complexas, baseadas nas transformações não lineares dos valores X, Y e Z em L*, a*, b*, C* e h°. A determinação da incerteza dos resultados dados em coordenadas CIELAB ou expressos em fórmulas de diferenças (delta)E*, (delta) ECMC ou CIE (delta) E2000 é fundamental no controle instrumental das cores em qualquer indústria. À base de um número elevado de medições repetidas de várias amostras têxteis e padrões cerâmicos, são analisadas a distribuição e outras características estatísticas dos valores R(lambda) diretamente medidos, e - usando o método de propagação de erros - são calculadas as incertezas das medições em termos colorimétricos. A pesquisa de mestrado objeto do presente trabalho desenvolve- se sob a égide de um convênio de cooperação que o Programa de Pós-Graduação em Metrologia da PUC-Rio está celebrando com o SENAI/CETIQT, viabilizado a inclusão dessa pesquisa dentre os dez projetos-piloto que participaram do Convênio FINEP/MCT número 22.01.0692.00, Referência 1974/01, que aportou recursos do Fundo Setorial Verde Amarelo para direcionar o esforço de pesquisa em metrologia para a solução de um problema de interesse do setor têxtil que fez uso de conhecimentos avançados de metrologia da cor. Relacionado à demanda de medições espectrofotométricas com elevado controle metrológico, o desenvolvimento e a orientação acadêmico-científica da presente dissertação de mestrado deu-se nas instalações do SENAI/CETIQT, que possui comprovada competência técnica e científica na área e uma adequada infra-estrutura laboratorial em metrologia da cor de suporte ao trabalho.
Colorimetry - Propagation of Errors and Uncertainty Calculations in Spectrophotometric Measurements treats the measurement of the colour of objects, based on the measurement of spectral irradiance (self-luminous objects) or that of spectral reflectance or transmittance (opaque or transparent objects), followed by colorimetric calculations according to the CIE system. Measurements are generally made in 5nm (or 10 nm) intervals in the spectral range of 360 to 780nm, and the 3 tristimulus values (X, Y and Z) are calculated from the 42-84 measurement points by standard equations. The statistical distribution of the measured R (lambda) values is probably normal; the correlation between the values varies depending on their position in the spectrum. The distribution of and the correlation between the X, Y and Z values are not known and they depend on the form of the spectral curve of each colour and on the operation of the measuring instrument. Complex formulae are used in the instrumental control of colours based on non-linear transformations of the X, Y and Z values into L*a*b*C*h°. The determination of the uncertainty of the results given in CIELAB coordinates or expressed in one of the colour difference formulae (delta)E*, (delta)ECMC or CIE(delta) E2000 is fundamental in the instrumental control of colours in any industry. Based on a large number of repeated measurements of different textile samples and ceramic standards, the distribution and other statistical characteristics of the directly measured R(lambda) values are analysed and - using the propagation of errors method - the uncertainties are calculated in colorimetric terms. The present research, a M. Sc. Dissertation work, was developed under the auspices of a co-operation agreement celebrated between the Post-graduate Programme in Metrology of PUC-Rio and SENAI/CETIQT, allowing for the inclusion of this M.Sc. Dissertation among the ten pilot projects which benefited from the financial support received from the FINEP/MCT Agreement number 22.01.0692.00, Reference 1974/01 (Fundo Verde-Amarelo). The project aims at driving the research effort in metrology to the solution of industrial problems, in this case the solution of a problem identified within the textile sector which requires to its solution advanced knowledge of colour metrology. Related the spectrophotometer measurements under the highest level of metrological control, the development and academic-scientific supervision of this M. Sc. Dissertation was performed at the laboratory facility of SENAI/CETIQT, an institution with proven technical and scientific competence in the field having sophisticated and well equipped laboratories in colour metrology meeting the measurement requirements needed to support the development of this research.
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Greenall, Nicholas Robert. "Parameter extraction and uncertainty in terahertz time-domain spectroscopic measurements." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/19045/.
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Terahertz (THz) time domain spectroscopy is emerging as a powerful tool to characterise samples both chemically and physically. In this work different methods of estimating spectroscopic parameters of a sample, its thickness and the uncertainty of these estimates is presented. A number of case studies are also examined including paracetamol polymorphs and a method of creating a spectroscopic simulant of Semtex-H is presented. Approximation of the sample spectroscopic parameters, real refractive index and absorption coeficient were formed by building up a simple model of the samples interaction with THz radiation. Methods of correcting unwrapping error in the real refractive index were developed, including a method to correct in the presence of discontinuities in the refractive index itself. These approximations were then applied to extract parameters of both lactose and paracetamol samples. An algorithm to generate spectroscopic simulants was developed and applied to Semtex-H. These simulants consisted of simple mixtures of inert compounds, which were measured and found to have similar spectrum to the target sample. Methods of fitting resonant models to the sample response were developed to extract both the spectroscopic parameters and sample thickness. These were refined by calibrating for the Gaussian beam profile of the THz radiation, which was shown to increase the accuracy of the extracted thickness. The thickness and spectroscopic parameters of a lactose sample were measured with temperature, and it was found that the spectroscopic parameter change was underestimated when thickness was assumed constant. A resonant model for multilayered samples was then developed and used to characterise IPA in a flowcell measurement. This was then combined with a method of time segmentation of the sample response, to extract spectroscopic parameters and sample thickness simultaneously. This was then applied to a two layer sample, to extract the spectroscopic parameters of a silicon and a quartz layer from a single measurement. Finally, methods of propagating the uncertainty from the time domain to the spectroscopic parameters were developed. These were based on a multivariate normal statistical model of the measurements andwere compared to numerical bootstrap and Monte–Carlo estimates. These were used to develop confidence intervals for the extracted refractive index, absorption coefficient and thickness. These methods were applied to both a lactose and quartz sample.
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Ambrosini, Marco <1976>. "The uncertainty in standardised sound power measurements: complying with ISO 17025." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1243/.
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In the context of “testing laboratory” one of the most important aspect to deal with is the measurement result. Whenever decisions are based on measurement results, it is important to have some indication of the quality of the results. In every area concerning with noise measurement many standards are available but without an expression of uncertainty, it is impossible to judge whether two results are in compliance or not.
ISO/IEC 17025 is an international standard related with the competence of calibration and testing laboratories. It contains the requirements that testing and calibration laboratories have to meet if they wish to demonstrate that they operate to a quality system, are technically competent and are able to generate technically valid results. ISO/IEC 17025 deals specifically with the requirements for the competence of laboratories performing testing and calibration and for the reporting of the results, which may or may not contain opinions and interpretations of the results. The standard requires appropriate methods of analysis to be used for estimating uncertainty of measurement.
In this point of view, for a testing laboratory performing sound power measurement according to specific ISO standards and European Directives, the measurement of uncertainties is the most important factor to deal with.
Sound power level measurement, according to ISO 3744:1994 , performed with a limited number of microphones distributed over a surface enveloping a source is affected by a certain systematic error and a related standard deviation. Making a comparison of measurement carried out with different microphone arrays is difficult because results are affected by systematic errors and standard deviation that are peculiarities of the number of microphones disposed on the surface, their spatial position and the complexity of the sound field. A statistical approach could give an overview of the difference between sound power level evaluated with different microphone arrays and an evaluation of errors that afflict this kind of measurement. Despite the classical approach that tend to follow the ISO GUM this thesis present a different point of view of the problem related to the comparison of result obtained from different microphone arrays.
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Thekkadath, Guillaume. "Joint Measurements of Complementary Properties of Quantum Systems." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36669.
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In quantum mechanics, measurements disturb the state of the system being measured. This disturbance is largest for complementary properties (e.g. position and momentum) and hence limits the precision with which such properties can be determined simultaneously. Often, this fact is conflated with Heisenberg's uncertainty principle, which refers to an uncertainty relation between complementary properties that is intrinsic to quantum states. In this thesis, the distinction between these two fundamental characteristics of quantum mechanics is made clear. At the intersection of the two are "joint measurements", which circumvent measurement disturbance to simultaneously determine complementary properties. They have applications in quantum metrology and enable a direct measurement of quantum states. The focus of this thesis is on the latter.
The thesis is structured in the following way. The first chapter serves as an introduction to joint measurements. It surveys the seminal works in the field, doing so in a chronological manner to provide some historical context. The remainder of the thesis discusses two strategies to experimentally achieve joint measurements. The first strategy is to sequentially measure the complementary properties, making these measurements weak so that they do not disrupt each other. The second strategy is to first clone the system being measured, and then measure each complementary property on a separate clone. Both strategies are experimentally demonstrated on polarized photons, but can be readily extended to other systems.
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Binder, Tanja [Verfasser], and Ekaterina [Akademischer Betreuer] Kostina. "Optimization under uncertainty : robust parameter estimation with erroneous measurements and uncertain model coefficients / Tanja Binder. Betreuer: Ekaterina Kostina." Marburg : Philipps-Universität Marburg, 2013. http://d-nb.info/1032315245/34.
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Valverde, Mora Gustavo Adolfo. "Uncertainty and state estimation of power systems." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/uncertainty-and-state-estimation-of-power-systems(18c48a22-7ea2-4db2-9112-078a1eac6fe7).html.
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The evolving complexity of electric power systems with higher levels of uncertainties is a new challenge faced by system operators. Therefore, new methods for power system prediction, monitoring and state estimation are relevant for the efficient exploitation of renewable energy sources and the secure operation of network assets. In order to estimate all possible operating conditions of power systems, this Thesis proposes the use of Gaussian mixture models to represent non-Gaussian correlated input variables, such as wind power output or aggregated load demands in the probabilistic load flow problem. The formulation, based on multiple Weighted Least Square runs, is also extended to monitor distribution radial networks where the uncertainty of these networks is aggravated by the lack of sufficient real-time measurements. This research also explores reduction techniques to limit the computational demands of the probabilistic load flow and it assesses the impact of the reductions on the resulting probability density functions of power flows and bus voltages. The development of synchronised measurement technology to support monitoring of electric power systems in real-time is also studied in this work. The Thesis presents and compares different formulations for incorporating conventional and synchronised measurements in the state estimation problem. As a result of the study, a new hybrid constrained state estimator is proposed. This constrained formulation makes it possible to take advantage of the information from synchronised phasor measurements of branch currents and bus voltages in polar form. Additionally, the study is extended to assess the advantages of PMU measurements in multi-area state estimators and it explores a new algorithm that minimises the data exchange between local area state estimators. Finally, this research work also presents the advantages of dynamic state estimators supported by Synchronised Measurement Technology. The dynamic state estimator is compared with the static approach in terms of accuracy and performance during sudden changes of states and the presence of bad data. All formulations presented in this Thesis were validated in different IEEE test systems.
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Taylor, Paul. "Uncertainty of geochemical measurements of contaminated land : causes, estimation and cost-based optimisation." Thesis, University of Sussex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289224.
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Fleming, Austin. "Uncertainty Qualification of Photothermal Radiometry Measurements Using Monte Carlo Simulation and Experimental Repeatability." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3299.
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Photothermal Radiometry is a common thermal property measurement technique which is used to measure the properties of layered materials. Photothermal Radiometry uses a modulated laser to heat a sample, in which the thermal response can be used to determine the thermal properties of layers in the sample. The motivation for this work is to provide a better understanding of the accuracy and the repeatability of the Photothermal Radiometry measurement technique. Through this work the sensitivity of results to input uncertainties will be determined. Additionally, using numerical simulations the overall uncertainty on a theoretical measurement will be determined.
The repeatability of Photothermal Radiometry measurements is tested with the use of a proton irradiated zirconium carbide sample. Due to the proton irradiation this sample contains two layers with a thermal resistance between the layers. This sample has been independently measured by three different researchers, in three different countries and the results are compared to determine the repeatability of Photothermal Radiometry measurements. Finally, from sensitivity and uncertainty analysis experimental procedures and suggestions are provided to reduce the uncertainty in experimentally measured results.
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Simmons, Christian. "Managing uncertainty in building acoustics : comparisons of predictions using the EN 12354 standards to measurements /." Luleå : Department of Human Work Sciences, Division of Sound and Vibration, Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/3404226.
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Moorthy, K. S. "An exploratory study of pre-service primary teachers' understanding of uncertainty in measurements in Singapore." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11188/.
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This study was set in the context of a reform agenda for Singapore’s science curriculum to adopt inquiry in teaching and learning science (MOE, 2008). Teachers, including pre-service primary teachers (PSTs) who were subjects of this study, are expected to engage their students with scientific evidence including measurements taken during science investigations. The inherent nature of measurements is that they are always affected by errors that caused uncertainty. Understanding this, as well as other procedural ideas underpinning uncertainty would be important for understanding evidence before looking at data that are subjected to uncertainties in measurements. Such understandings would be important for the PSTs when they teach their future students how to obtain valid and reliable data, and to evaluate the methods of investigation or scientific conclusions based on evidence. This study, therefore, was aimed at exploring such understandings using the Concepts of Evidence (Gott, Duggan, and Roberts, 2008) as a theoretical framework. The lack of a research instrument customised to such a need motivated this study to develop one. The study was carried out in two phases. The first involved fifty-five PSTs and directed towards getting an accurate interpretation of procedural ideas underlying uncertainty by triangulating the evidence from questionnaire and interviews and iteratively refining the “probes” as the study progressed. The second phase focused on developing a questionnaire based on findings from the first and testing it on twenty PSTs. The results revealed that most PSTs could recognise uncertainties in measurements and suggest the right actions to deal with them, but they generally had difficulties explaining their actions implying shallow understanding of concepts underpinning uncertainty, and reliance on routine knowledge. This has strong implications for teacher preparatory programmes as well as the teaching of procedural understanding.
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Otgonbaatar, Uuganbayar. "Methodology for characterization of representativeness uncertainty in performance indicator measurements of thermal and nuclear power plants." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107279.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 327-331).
In this thesis, a general Methodology framework to characterize, assess and quantify the representativeness uncertainty in performance indicator measurements in thermal and nuclear plants is presented. The representativeness uncertainty arises from the inherent heterogeneity or the variability of the quantity being measured or from the inadequacy of the physical models used to simulate the measurement. The main objective of the Methodology is to gain a deeper physical understanding of the Representativeness uncertainty of the measurement by using numerical simulation tools such as Computational Fluid Dynamics (CFD) and to quantify various sources of representativeness uncertainty. First, the components of the Methodology are expressed using the normal probability distribution for the uncertainty sources. Second, a non-parametric formulation of the Methodology framework is developed and demonstrated. The use of non-parametric techniques allows the quantification and integration of uncertainties that are not expressed by the normal probability distribution. The Methodology is developed based on the analysis of four industrial Case Studies involving uncertainties in performance indicator measurements to structure the analysis. They are: Mass flow rate measurement by an orifice plate (Case Study 1), Steam Generator recirculation ratio measurement using chemical tracers (Case Study 2), The simulation of cooling tower deformation using a Photomodeler (Case Study 3) and the NOx emission measurement from a Combined Cycle Gas Turbine (Case Study 4). In Case Study 1, the non-parametric bootstrap method was used to quantify sampling, iterative and discretization uncertainties thus demonstrating its applicability to CFD uncertainty analysis. In Case Studies 2,3 and 4, the parametric formulation of the Methodology is used to structure the technical analysis.
by Uuganbayar Otgonbaatar.
Ph. D.
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Büttner, Lars, Felix Schmieder, Martin Teich, Nektarios Koukourakis, and Jürgen Czarske. "Application of adaptive optics for flexible laser induced ultrasound field generation and uncertainty reduction in measurements." SPIE, 2017. https://tud.qucosa.de/id/qucosa%3A35156.
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The availability of spatial light modulators as standard turnkey components and their ongoing development makes them attractive for a huge variety of optical measurement systems in industry and research. Here, we outline two examples of how optical measurements can benefit from spatial light modulators.
Ultrasound testing has become an indispensable tool for industrial inspection. Contact-free measurements can be achieved by laser-induced ultrasound. One disadvantage is that due to the highly divergent sound field of the generated shear waves for a point-wise thermoelastic excitation, only a poor spatial selectivity can be achieved. This problem can be solved by creating an ultrasound focus by means of a ring-like laser intensity distribution, but standard fixed-form optical components used for their generation are always optimised to a fixed set of parameters. Here, we demonstrate, how a predefined intensity pattern as e.g. a ring can be created from an arbitrary input laser beam using a phase-retrieval algorithm to shape an ultrasound focus in the sample.
By displaying different patterns on the spatial light modulator, the focus can be traversed in all three directions through the object allowing a fast and highly spatially resolving scanning of the sample.
Optical measurements take often place under difficult conditions. They are affected by variations of the refractive index, caused e.g. by phase boundaries between two media of different optical density. This will result in an increased measurement uncertainty or, in the worst case, will cause the measurement to fail. To overcome these limitations, we propose the application of adaptive optics. Optical flow velocity measurements based on image correlation in water that are performed through optical distortions are discussed. We demonstrate how the measurement error induced by refractive index variations can be reduced if a spatial light modulator is used in the measurement setup to compensate for the wavefront distortions.
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Guo, Kai Chen. "Passive localization in quasi-synchronous sensor networks with sensor uncertainty and Non-Line of-Sight measurements." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691130.
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Lark, Adam Christopher. "Implementation of Scientific Community Laboratories and Their Effect on Student Conceptual Learning, Attitudes, and Understanding of Uncertainty." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1396537933.
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Nelson, Michael Allan. "Stereoscopic Particle Image Velocimetry Measurements of Swirl Distortion on a Full-Scale Turbofan Engine Inlet." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64993.
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There is a present need for simulation and measuring the inlet swirl distortion generated by airframe/engine system interactions to identify potential degradation in fan performance and operability in a full-scale, ground testing environment. Efforts are described to address this need by developing and characterizing methods for complex, prescribed distortion patterns. A relevant inlet swirl distortion profile that mimics boundary layer ingesting inlets was generated by a novel new method, dubbed the StreamVane method, and measured in a sub scale tunnel using stereoscopic particle image velocimetry (SPIV) as a precursor for swirl distortion generation and characterization in an operating turbofan research engine. Diagnostic development efforts for the distortion measurements within the research engine paralleled the StreamVane characterization. The system used for research engine PIV measurements is described. Data was obtained in the wake of a total pressure distortion screen for engine conditions at idle and 80% corrected fan speed, and of full-scale StreamVane screen at 50% corrected fan speed. The StreamVane screen was designed to generate a swirl distortion that is representative for hybrid wing body applications and was made of Ultem*9085 using additive manufacturing. Additional improvements to the StreamVane method are also described. Data reduction algorithms are put forth to reduce spurious velocity vectors. Uncertainty estimations specific to the inlet distortion test rig, including bias error due to mechanical vibration, are made. Results indicate that the methods develop may be used to both generate and characterize complex distortion profiles at the aerodynamic interface plane, providing new information about airframe/engine integration.Master of Science
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Glass, Deborah Catherine, and mikewood@deakin edu au. "Exposure estimation, uncertainty and variability in occupational hygiene retrospective assessment." Deakin University. School of Biological and Chemical Sciences, 1999. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20051017.142634.
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This thesis reports on a quantitative exposure assessment and on an analysis of the attributes of the data used in the estimations, in particular distinguishing between its uncertainty and variability.
A retrospective assessment of exposure to benzene was carried out for a case control study of leukaemia in the Australian petroleum industry. The study used the mean of personal task-based measurements (Base Estimates) in a deterministic algorithm and applied factors to model back to places, times etc for which no exposure measurements were available. Mean daily exposures were estimated, on an individual subject basis, by summing the task-based exposures. These mean exposures were multiplied by the years spent on each job to provide exposure estimates in ppm-years. These were summed to provide a Cumulative Estimate for each subject.
Validation was completed for the model and key inputs.
Exposures were low, most jobs were below TWA of 5 ppm benzene. Exposures in terminals were generally higher than at refineries. Cumulative Estimates ranged from 0.005 to 50.9 ppm-years, with 84 percent less than 10 ppm-years.
Exposure probability distributions were developed for tanker drivers using Monte Carlo simulation of the exposure estimation algorithm. The outcome was a lognormal distribution of exposure for each driver. These provide the basis for alternative risk assessment metrics e.g. the frequency of short but intense exposures which provided only a minimal contribution to the long-term average exposure but may increase risk of leukaemia.
The effect of different inputs to the model were examined and their significance assessed using Monte Carlo simulation. The Base Estimates were the most important determinant of exposure in the model. The sources of variability in the measured data were examined, including the effect of having censored data and the between and within-worker variability. The sources of uncertainty in the exposure estimates were analysed and consequential improvements in exposure assessment identified.
Monte Carlo sampling was also used to examine the uncertainties and variability associated with the tanker drivers' exposure assessment, to derive an estimate of the range and to put confidence intervals on the daily mean exposures. The identified uncertainty was less than the variability associated with the estimates.
The traditional approach to exposure estimation typically derives only point estimates of mean exposure. The approach developed here allows a range of exposure estimates to be made and provides a more flexible and improved basis for risk assessment.
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Dokoupil, Pavel. "Nejistota měření přetvoření a mechanického napětí pomocí odporových tenzometrů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-371773.
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The dissertation thesis deals with the determination of uncertainty of strain measurement and the stress using resistance strain gages. You can find two methods to define the uncertainty in the thesis, GUF and MMC, and both are applied for measurements carried out with resistance strain gages. Definition of the measurement uncertainty was set for the strain measured by uniaxial and biaxial strain gages. The uncertainty of the stress was defined for linear strain gages, T Rosettes and Rosettes. There were universal mathematic-technical models defined to measure strain and stress, these models can be used either for standard and special measurements i.e. high-temperature, or for measurements in radiation field. Each part of the strain uncertainty and stress is analyzed from the point of view of a size of uncertainty and a form of probability of the function that strain and stress can adopt. The maximum focus was dedicated to the mistakes influencing measured strain like strain gage properties, installation and operating influences, external influences, time effects and the influence of the measured object. There are two mistakes influencing the stress described and analyzed in the thesis, the mistake of the Young’s modulus of elasticity and the mistake of the Poisson’s ratio. The thesis is conceived as a complex of information related to the measurement uncertainties using the resistance strain gages and methods of defining the measurement uncertainty in a way that the experimenter can apply the gained info and methods in the required measurements. The final chapters give representative examples to define measurement uncertainties for uniaxial and biaxial stress applying GUF and MMC method. The thesis also includes the experiment that compares measured values of strain, stress and measurement uncertainties, using several different types of strain gages at different temperatures, with theoretical calculation of strain and with stress. The experiment was carried out using the displacement sensor that works on an elementary principle of bending load.
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Schaap, Robert. "Best Practices for Volume Flow Rate Measurements Using PIV at the Exit of a Turbulent Round Jet." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6274.
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Particle image velocimetry (PIV) is an optical flow measurement technique that is used to measure volume flow rate at the exit of a turbulent, round nozzle. The objective of this thesis is to determine how to best make this measurement. The quality of the measurement is affected by a range of data acquisition parameters and how data are processed. Measurements are made over a range of different flows using the two main types of PIV: Two Component (2C), which uses one camera, and Stereo, which uses two cameras, similar to human eyes. Previous work done for data acquisition and processing of PIV in general is found to apply. Different parameters are tested, evaluated, and discussed. Both 2C PIV and Stereo PIV were found to underestimate flow by approximately 2%.
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Anning, David William. "Estimation and analysis of the uncertainty in streamflow and change in reservoir-content data at selected streamflow-gaging stations in the lower Colorado River network, 1995-99." Thesis, The University of Arizona, 2002. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0185_sip1_w.pdf&type=application/pdf.
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Thesis (M.S. - Hydrology and Water Resources)--University of Arizona.Appendix A: Standard errors of annual discharge and change in reservoir content data from selected stations in the lower Colorado River streamflow-gaging station network, 1995-99 (Water-resources investigations report no.01-4240) Includes bibliographical references (leaf 44).
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Lamoreaux, Ryan D. "Impacts of Distributions and Trajectories on Navigation Uncertainty Using Line-of-Sight Measurements to Known Landmarks in GPS-Denied Environments." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6892.
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Unmanned vehicles are increasingly common in our world today. Self-driving ground vehicles and unmanned aerial vehicles (UAVs) such as quadcopters have become the fastest growing area of automated vehicles research. These systems use three main processes to autonomously travel from one location to another: guidance, navigation, and controls (GNC). Guidance refers to the process of determining a desired path of travel or trajectory, affecting velocities and orientations. Examples of guidance activities include path planning and obstacle avoidance. Effective guidance decisions require knowledge of one’s current location. Navigation systems typically answer questions such as: “Where am I? What is my orientation? How fast am I going?” Finally, the process is tied together when controls are implemented. Controls use navigation estimates (e.g., “Where I am now?”) and the desired trajectory from guidance processes (e.g., “Where do I want to be?”) to control the moving parts of the system to accomplish relevant goals.
Navigation in autonomous vehicles involves intelligently combining information from several sensors to produce accurate state estimations. To date, global positioning systems(GPS) occupy a crucial place in most navigation systems. However, GPS is not universally reliable. Even when available, GPS can be easily spoofed or jammed, rendering it useless. Thus, navigation within GPS-denied environments is an area of deep interest in both military and civilian applications. Image-aided inertial navigation is an alternative navigational solution in GPS-denied environments. One form of image-aided navigation measures the bearing from the vehicle to a feature or landmark of known location using a single lens imager, such as a camera, to deduce information about the vehicle’s position and attitude.
This work uncovers and explores several of the impacts of trajectories and land mark distributions on the navigation information gained from this type of aiding measurement. To do so, a modular system model and extended Kalman filter (EKF) are described and implemented. A quadrotor system model is first presented. This model is implemented and then used to produce sensor data for several trajectories of varying shape, altitude, and landmark density. Next, navigation data is produced by running the sensor data through an EKF. The data is plotted and examined to determine effects of each variable. These effects are then explained. Finally, an equation describing the quantity of information in each measurement is derived and related to the patterns seen in the data. The resulting equation is then used to explain selected patterns in the data. Other uses of this equation are presented, including applications to path planning and landmark placement.
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Yoon, Hyunse. "Phase-averaged stereo-PIV flow field and force/moment/motion measurements for surface combatant in PMM maneuvers." Diss., University of Iowa, 2009. https://ir.uiowa.edu/etd/453.
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Towing-tank experiments are performed for a surface combatant as it undergoes static and dynamic planar motion mechanism maneuvers in calm water. The data includes global forces/moment/motions and phase-averaged local flow-fields, and uncertainty assessment. The geometry is DTMB model 5512, which is a 1/46.6 scale geosym of DTMB model 5415, with L = 3.048 m. The experiments are performed in a 3.048 × 3.048 × 100 m towing tank. The measurement system features a custom designed planar motion mechanism, a towed stereoscopic particle image velocimetry system, a Krypton contactless motion tracker, and a 6-component loadcell. The forces/moment and UA are conducted in collaboration with two international facilities (FORCE and INSEAN), including test matrix and overlapping tests using the same model geometry but with different scales. Quality of the data is assessed by monitoring the statistical convergence, including tests for randomness, stationarity, and normality. Uncertainty is assessed following the ASME Standards (1998 and 2005). Hydrodynamic derivatives are determined from the forces/moment data by using the Abkowitz (1966) mathematical model, with two different 'Multiple-Run (MR)' and 'Single-Run (SR)' methods. The results for reconstructions of the forces/moment indicate that usually the MR method is more accurate than the SR. Comparisons are made of the hydrodynamic derivatives across different facilities. The scale effect is small for sway derivatives, whereas considerable for yaw derivatives. Heave, pitch, and roll motions exhibit cross-coupling between the motions and forces and moment data, as expect based on ship motions theory. Hydrodynamic derivatives are compared between different mount conditions. Linear derivatives values are less sensitive to the mounting conditions, whereas the non-linear derivatives are considerably different. Phase-averaged flowfield results indicate maneuvering-induced vortices and their interactions with the turbulent boundary layer. The tests are sufficiently documented and detailed so as to be useful as benchmark EFD data for CFD validation.
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Lodwick, Camille J. "Mathemeatical simulations of photon interactions using Monte Carlo analysis to evaluate the uncertainty associated with in vivo K xray fluorescence measurements of stabe lead in bone." Cincinnati, Ohio : University of Cincinnati, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1059400723.
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Štarhová, Marie. "Posouzení metody využívající přenosnou měřicí sestavu s průtokoměrem." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372080.
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This diploma thesis deals with the assessment of flow measurement method using portable measuring set with the flowmeter used in the field of official measurement in the free surface profiles. This method is a controlled simulation of the required flow through a portable measurement set. This approach is innovative in relation to other methods of official measurement in which direct flow measurement is carried out. The thesis is based on extensive literary research related to elementary element of this assembly – flowmeter. On the basis of individual characteristics, the technical and metrological requirements for both the flowmeter and the other elements of the measuring set are processed. In the context of these findings and the requirements of the official measurement, input sources of measurement uncertainties are further defined and subsequently calculated by this assembly. The findings from this thesis are fully applicable to the practice of institution authorized for the official measurement of the subject method.
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Gregor, Jaroslav. "ANALÝZA ZPŮSOBILOSTI VÝROBNÍHO STROJE PŘI VÝROBĚ AUTOBUSŮ." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227944.
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The diploma thesis deals with an analysis of the processing machine capability in bus production. The goal is to evaluate the capability of the CNC laser processing machine in conditions of Iveco Czech Republic, Ltd., Vysoke Myto. In the theoretical part, the thesis studies measurements and capability of the processing machine; the practical part describes the present state of production and suggests a solution of the assigned task.
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Wronska, Louisa Victoria May. "The factors & protocols that influence accuracy, precision & uncertainty of accurate mass measurements by Fourier transform ion cyclotron resonance mass spectrometry to validate the assignment of elemental composition." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/67059/.
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The need for very accurate mass measurements of compounds is becoming more demanding with the expansion of the number of compounds in need of correct identification and with the limits of elemental analysis; a fast, robust analytical solution is sought. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is a very powerful tool for undertaking accurate mass measurements because of its high resolving power and mass accuracy. The use of FT-ICR MS in a high-throughput environment is limited due to the need of operator intervention required to obtain optimum accurate mass measurements. The lowest mass measurement errors (MME) are usually obtained using internal calibration, as the sample and calibrant ions inside the ICR cell experience the same conditions. However, internal calibration requires calibrant ions to be selected according to the mass of the sample ion, which requires operator intervention. External calibration is the preferred choice when performing accurate mass measurements in a high-throughput environment, as a calibration can be acquired independently of the sample. This study aims to demonstrate the use of ion population balancing using a dual sprayer approach to reduce MME. Population balancing between sample ions and calibrant ions can reduce the MME 40-fold. Ion populations across a chromatographic run can also vary greatly. The dual sprayer can also be employed to easily control the ion populations of both sample and calibrant entering the cell and can help to reduce ion suppression. The aim of the latter part of the work was to address the uncertainty of an accurate mass measurement performed using FT-ICR MS. In order to confidently select an elemental formula following an accurate mass measurement, a ‘cut-off’ limit or tolerance has to be selected. This tolerance can be set by calculating the uncertainty of the measurement; without an uncertainty component the measurement is meaningless. The work herein demonstrates how to calculate uncertainty of an accurate mass measurement with the aim that journals will adopt a procedure of only accepting an accurate mass measurement which quotes an uncertainty.
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LODWICK, CAMILLE JANAE. "MATHEMATICAL SIMULATIONS OF PHOTON INTERACTIONS USING MONTE CARLO ANALYSIS TO EVALUATE THE UNCERTAINTY ASSOCIATED WITH IN VIVO K X-RAY FLUORESCENCE MEASUREMENTS OF STABLE LEAD IN BONE." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1059400723.
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Valdová, Klára. "Posouzení metody stanovení průtoku jímáním kapaliny do odměrné nebo vážicí nádoby." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240089.
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This diploma thesis is concerned with assessment of two methods of gauging the flow rate used in the sphere of official measurements on profiles with an unrestricted water level. This is the method of collecting liquid into a volumetric vessel and the method of collecting liquid into a weighing vessel (pouch). The main purpose of this work was to specify uncertainties determined using method A and B for these two methods of gauging flow rate within the terms of addressing the Metrology Development Plan of the Czech Office for Standards, Metrology and Testing, because these uncertainties were previously determined using older methodology and using less accurate flow rate benchmarks. The entire work is based on extensive experimental measurement of the flow rate, using the assessed methods, executed at the Laboratory of Water Management Research in Brno. The method of collecting liquids into a volumetric vessel was assessed using four various vessel volumes - 9 l, 15 l, 30 l and 50 l. Relative uncertainties determined using method A and B in relation to flow rate are determined for each vessel in the experimental section of this work. Within the scope of this thesis, these uncertainties were also determined for the method of collection of liquid into weighing vessel (pouch), which was assessed for flow rates of from 0,5 l/s to 10,0 l/s.
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Dokoupil, Pavel. "Měření napjatosti ve spirále vodní turbíny pomocí tenzometrů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231230.
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The Master‘s thesis is focused on measuring of the stress in the spiral case of water turbine using the strain gauges measurement. It contains the theoretical and the practical part. The theoretical part includes a description of theoretical background (basic mechanics, measurement and evaluation, strain gauges, pressure measurement, uncertainty of measurement). One of the chapters describes Water Power Plant Lipno nad Vltavou (history of power plant, issues and the history of measurement). The practical part contains a theoretical calculation of measurement uncertainty and measuring of stress on spiral case Francis turbine at Water Power Plant Lipno I (Unit TG2). Measurement was made before and after overhaul. There are described technical data of spiral cases, description of measurement, results of measuring of strain and stress including comparison with the pressure in spiral case and calculation of uncertainties of measurement.
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Berny, Myriam. "High-temperature tests for ceramic matrix composites : from full-field regularised measurements to thermomechanical parameter identification." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST028.
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Cette thèse a pour objectif de développer une méthode de mesure de champs par corrélation d’images numériques (CIN) à haute température couplée à des mesures thermiques sur une éprouvette technologique en CMC sollicitée dans des conditions thermiques représentatives d’un environnement moteur et de mettre en place une méthodologie d’identification des propriétés thermiques et thermomécaniques du matériau, en quantifiant à chaque étape de la chaîne les incertitudes associées aux quantités d’intérêt et en les réduisant. Il a pour cela été nécessaire de traiter les défis inhérents à la CIN à chaud, que ce soit au niveau de l’acquisition des images (saturation, perte du contraste) ou de la mesure (artefacts dus à l’effet mirage, aussi appelé "brume de chaleur").Ces travaux ont ainsi donné lieu au développement d’un protocole d’étalonnage d’un banc multi-instrumenté par l’utilisation soit d’une mire in-situ, soit par auto-étalonnage en utilisant l’éprouvette elle-même et son environnement. Les mesures de déplacements 3D surfaciques (approches de stéréocorrélation globales) et les mesures thermiques ont permis de mettre en évidence ce phénomène de brume de chaleur. Des stratégies de régularisation spatiotemporelles des déplacements mesurés ont été proposées et ont permis d’obtenir des résultats satisfaisants (réduction significative des incertitudes de mesure). De même, des approches par réduction de modèles (POD) ont permis de traiter les données thermiques et de quantifier les incertitudes associées aux phénomènes convectifs. Enfin, un algorithme de recalage de modèle éléments finis pondéré sur les données de températures et de déplacements a été implémenté en vue d’identifier un ensemble de propriétés thermiques et thermomécaniques, en tenant compte de la sensibilité de chaque paramètre par rapport aux incertitudes de mesuresThe aim of this thesis is firstly to develop procedures of full-field measurements with Digital Image Correlation (DIC), coupled to thermal measurements, suitable for high-temperature experiments on CMC specimens under thermal conditions representative of an engine environment. Secondly, a methodology is proposed for identifying the thermal and thermomechanical properties of the material, quantifying at each stage of the chain the uncertainties associated with the quantities of interest and strategies to reduce them. It was necessary to deal with the challenges due to high temperatures, especially for DIC, either in terms of acquisition (saturation, loss of contrast) or measurement (artefacts due to the mirage effect, also called "heat haze effect").This work has led to the development of a calibration protocol for a multi-instrumented bench using either an in-situ calibration target or by self-calibration using the specimen itself and its environment. 3D surface displacement measurements (with global stereocorrelation approaches) and thermal measurements have made it possible to highlight the heat haze effect phenomenon. Spatiotemporal regularisation strategies of the measured displacements were proposed and allowed satisfactory results to be obtained (significant reduction of measurement uncertainties). Similarly, model reduction approaches (POD) have been used to process thermal data and quantify the uncertainties associated with convective phenomena. Finally, a weighted Finite-Element Model Updating (FEMU) algorithm on both temperature and displacement data was implemented in order to identify a set of thermal and thermomechanical properties, taking into account the sensitivity of each parameter with regard to measurement uncertainties
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Frazer, Robert Charles. "Measurement uncertainty in gear metrology." Thesis, University of Newcastle Upon Tyne, 2007. http://hdl.handle.net/10443/852.
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Gears play an important role in mechanical power transmission systems. They enable the prime mover characteristic (a gas turbine for example) to be matched to the characteristic of the driven load (say, a slow speed propeller), thus reducing the cost of both manufacturing and operating the system. The customer requirements for higher power density and lower noise demands more accurate gears. This imposes more stringent requirements on the measuring equipment that controls the quality of the manufacturing machines. Many gears have flank form and tooth spacing tolerances that are less then 10μm, and according to the so called `Golden rule', measuring equipment on the shop floor should have a measurement uncertainty of between 1 to 2μm. These are stringent requirements that demand the highest standards of metrology. Thus the need to accurately quantify the measurement uncertainty of inspection machines is of paramount importance if costly mistakes are to be avoided. The work reported in this thesis was completed as part of the activities undertaken by the author in his role as head of the UK National Gear Metrology Laboratory (NGML). The laboratory is accredited by the United Kingdom Accreditation Service (UKAS) for gear measurement and on-site calibration of gear measuring machines. The work is mainly experimental in nature. In fact, much of what is reported is centred on work undertaken with two artefact sets: one set consisting of 100mm diameter lead and profile artefacts and a second set of 200mm diameter artefacts. These gear artefacts are probably the most valuable in the world because of the volume and quality of the calibration data associated with them.
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Kim, Alisa. "Deep Learning for Uncertainty Measurement." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22161.
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Diese Arbeit konzentriert sich auf die Lösung des Problems der Unsicherheitsmessung und ihrer Auswirkungen auf Geschäftsentscheidungen, wobei zwei Ziele verfolgt werden: Erstens die Entwicklung und Validierung robuster Modelle zur Quantifizierung der Unsicherheit, wobei insbesondere sowohl die etablierten statistischen Modelle als auch neu entwickelte maschinelle Lernwerkzeuge zum Einsatz kommen. Das zweite Ziel dreht sich um die industrielle Anwendung der vorgeschlagenen Modelle. Die Anwendung auf reale Fälle bei der Messung der Volatilität oder bei einer riskanten Entscheidung ist mit einem direkten und erheblichen Gewinn oder Verlust verbunden.
Diese These begann mit der Untersuchung der impliziten Volatilität (IV) als Proxy für die Wahrnehmung der Unsicherheit von Anlegern für eine neue Klasse von Vermögenswerten - Kryptowährungen. Das zweite Papier konzentriert sich auf Methoden zur Identifizierung risikofreudiger Händler und nutzt die DNN-Infrastruktur, um das Risikoverhalten von Marktakteuren, das auf Unsicherheit beruht und diese aufrechterhält, weiter zu untersuchen. Das dritte Papier befasste sich mit dem herausfordernden Bestreben der Betrugserkennung 3 und bot das Entscheidungshilfe-modell, das eine genauere und interpretierbarere Bewertung der zur Prüfung eingereichten Finanzberichte ermöglichte.
Angesichts der Bedeutung der Risikobewertung und der Erwartungen der Agenten für die wirtschaftliche Entwicklung und des Aufbaus der bestehenden Arbeiten von Baker (2016) bot das vierte Papier eine neuartige DL-NLP-basierte Methode zur Quantifizierung der wirtschaftspolitischen Unsicherheit.
Die neuen Deep-Learning-basierten Lösungen bieten eine überlegene Leistung gegenüber bestehenden Ansätzen zur Quantifizierung und Erklärung wirtschaftlicher Unsicherheiten und ermöglichen genauere Prognosen, verbesserte Planungskapazitäten und geringere Risiken. Die angebotenen Anwendungsfälle bilden eine Plattform für die weitere Forschung.This thesis focuses on solving the problem of uncertainty measurement and its impact on business decisions while pursuing two goals: first, develop and validate accurate and robust models for uncertainty quantification, employing both the well established statistical models and newly developed machine learning tools, with particular focus on deep learning. The second goal revolves around the industrial application of proposed models, applying them to real-world cases when measuring volatility or making a risky decision entails a direct and substantial gain or loss. This thesis started with the exploration of implied volatility (IV) as a proxy for investors' perception of uncertainty for a new class of assets - crypto-currencies. The second paper focused on methods to identify risk-loving traders and employed the DNN infrastructure for it to investigate further the risk-taking behavior of market actors that both stems from and perpetuates uncertainty. The third paper addressed the challenging endeavor of fraud detection and offered the decision support model that allowed a more accurate and interpretable evaluation of financial reports submitted for audit. Following the importance of risk assessment and agents' expectations in economic development and building on the existing works of Baker (2016) and their economic policy uncertainty (EPU) index, it offered a novel DL-NLP-based method for the quantification of economic policy uncertainty. In summary, this thesis offers insights that are highly relevant to both researchers and practitioners. The new deep learning-based solutions exhibit superior performance to existing approaches to quantify and explain economic uncertainty, allowing for more accurate forecasting, enhanced planning capacities, and mitigated risks. The offered use-cases provide a road-map for further development of the DL tools in practice and constitute a platform for further research.
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Spank, Uwe, Barbara Köstner, Uta Moderow, Thomas Grünwald, and Christian Bernhofer. "Surface Conductance of Five Different Crops Based on 10 Years of Eddy-Covariance Measurements." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-214307.
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The Penman-Monteith (PM) equation is a state-of-the-art modelling approach to simulate evapotranspiration (ET) at site and local scale. However, its practical application is often restricted by the availability and quality of required parameters. One of these parameters is the canopy conductance. Long term measurements of evapotranspiration by the eddy-covariance method provide an improved data basis to determine this parameter by inverse modelling. Because this approach may also include evaporation from the soil, not only the ‘actual’ canopy conductance but the whole surface conductance (gc) is addressed. Two full cycles of crop rotation with five different crop types (winter barley, winter rape seed, winter wheat, silage maize, and spring barley) have been continuously monitored for 10 years. These data form the basis for this study. As estimates of gc are obtained on basis of measurements, we investigated the impact of measurements uncertainties on obtained values of gc. Here, two different foci were inspected more in detail. Firstly, the effect of the energy balance closure gap (EBCG) on obtained values of gc was analysed. Secondly, the common hydrological practice to use vegetation height (hc) to determine the period of highest plant activity (i.e., times with maximum gc concerning CO2-exchange and transpiration) was critically reviewed. The results showed that hc and gc do only agree at the beginning of the growing season but increasingly differ during the rest of the growing season. Thus, the utilisation of hc as a proxy to assess maximum gc (gc,max) can lead to inaccurate estimates of gc,max which in turn can cause serious shortcomings in simulated ET. The light use efficiency (LUE) is superior to hc as a proxy to determine periods with maximum gc. Based on this proxy, crop specific estimates of gc,maxcould be determined for the first (and the second) cycle of crop rotation: winter barley, 19.2 mm s−1 (16.0 mm s−1); winter rape seed, 12.3 mm s−1 (13.1 mm s−1); winter wheat, 16.5 mm s−1 (11.2 mm s−1); silage maize, 7.4 mm s−1 (8.5 mm s−1); and spring barley, 7.0 mm s−1 (6.2 mm s−1).
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Eriksson, Johan. "Gränssnitt för AOD-simulator." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51091.
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Att kunna simulera en AOD-process (Argon, OxygenandDecarburization) är i dagsläget möjligt med hjälp av en programvara. En sådan programvara används till utbildning och forskning för utveckling av rostfritt stål. Kobolde & Partners AB är ett företag som äger en sådan programvara. I detta projekt byggs programmet ut för att ge användare möjlighet att simulera en AOD-process med osäkerhet i mätdata. Genom detta kan forskare få ökad förståelse hur processens mätresultat skiljer sig med osäkerhet i mätdata.: Being able to simulate an AOD process (Argon, Oxygen andDecarburization) is possible nowadays with help of software. This kind ofsoftware is used for education andresearch for development of stainless steel. Kobolde & Partners AB is a company that owns this kind of software. This project will further develop this software to enable users to simulate an AOD process with uncertainty in measurement. This allows scientist to get more knowledge how a process measurement results
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Spank, Uwe, Barbara Köstner, Uta Moderow, Thomas Grünwald, and Christian Bernhofer. "Surface Conductance of Five Different Crops Based on 10 Years of Eddy-Covariance Measurements." Schweizerbart Science Publishers, 2016. https://tud.qucosa.de/id/qucosa%3A29981.
Full textAbstract:
The Penman-Monteith (PM) equation is a state-of-the-art modelling approach to simulate evapotranspiration (ET) at site and local scale. However, its practical application is often restricted by the availability and quality of required parameters. One of these parameters is the canopy conductance. Long term measurements of evapotranspiration by the eddy-covariance method provide an improved data basis to determine this parameter by inverse modelling. Because this approach may also include evaporation from the soil, not only the ‘actual’ canopy conductance but the whole surface conductance (gc) is addressed. Two full cycles of crop rotation with five different crop types (winter barley, winter rape seed, winter wheat, silage maize, and spring barley) have been continuously monitored for 10 years. These data form the basis for this study. As estimates of gc are obtained on basis of measurements, we investigated the impact of measurements uncertainties on obtained values of gc. Here, two different foci were inspected more in detail. Firstly, the effect of the energy balance closure gap (EBCG) on obtained values of gc was analysed. Secondly, the common hydrological practice to use vegetation height (hc) to determine the period of highest plant activity (i.e., times with maximum gc concerning CO2-exchange and transpiration) was critically reviewed. The results showed that hc and gc do only agree at the beginning of the growing season but increasingly differ during the rest of the growing season. Thus, the utilisation of hc as a proxy to assess maximum gc (gc,max) can lead to inaccurate estimates of gc,max which in turn can cause serious shortcomings in simulated ET. The light use efficiency (LUE) is superior to hc as a proxy to determine periods with maximum gc. Based on this proxy, crop specific estimates of gc,maxcould be determined for the first (and the second) cycle of crop rotation: winter barley, 19.2 mm s−1 (16.0 mm s−1); winter rape seed, 12.3 mm s−1 (13.1 mm s−1); winter wheat, 16.5 mm s−1 (11.2 mm s−1); silage maize, 7.4 mm s−1 (8.5 mm s−1); and spring barley, 7.0 mm s−1 (6.2 mm s−1).
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Calkins, Joseph Matthew. "Quantifying Coordinate Uncertainty Fields in Coupled Spatial Measurement systems." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28472.
Full textAbstract:
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.
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Zhao, Lei. "Bench scale apparatus measurement uncertainty and uncertainty effects on measurement of fire characteristics of material systems." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-050105-182456/.
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Hoa, Phan Le Phuong. "Uncertainty in measurement of piezoresistive sensors /." Dresden : W.e.b.-Univ.-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2660800&prov=M&dok_var=1&dok_ext=htm.
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Abbott, David Scot. "Assessing Student Understanding of Measurement and Uncertainty." NCSU, 2003. http://www.lib.ncsu.edu/theses/available/etd-06172003-143358/.
Full textAbstract:
A test to assess student understanding of measurement and uncertainty has been developed and administered to more than 500 students at two large research universities. The aim is two-fold: 1) to assess what students learn in the first semester of introductory physics labs and 2) to uncover patterns in student reasoning and practice. The forty minute, eleven item test focuses on direct measurement and student attitudes toward multiple measurements. After one revision cycle using think-aloud interviews, the test was administered to students to three groups: students enrolled in traditional laboratory lab sections of first semester physics at North Carolina State University (NCSU), students in an experimental (SCALE-UP) section of first semester physics at NCSU, and students in first semester physics at the University of North Carolina at Chapel Hill. The results were analyzed using a mixture of qualitative and quantitative methods. In the traditional NCSU labs, where students receive no instruction in uncertainty and measurement, students show no improvement on any of the areas examined by the test. In SCALE-UP and at UNC, students show statistically significant gains in most areas of the test. Gains on specific test items in SCALE-UP and at UNC correspond to areas of instructional emphasis. Test items were grouped into four main aspects of performance: ?point/set? reasoning, meaning of spread, ruler reading and ?stacking.? Student performance on the pretest was examined to identify links between these aspects. Items within each aspect are correlated to one another, sometimes quite strongly, but items from different aspects rarely show statistically significant correlation. Taken together, these results suggest that student difficulties may not be linked to a single underlying cause. The study shows that current instruction techniques improve student understanding, but that many students exit the introductory physics lab course without appreciation or coherent understanding for the concept of measurement uncertainty.
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Hainsworth, G. D. "Measurement uncertainty in water distribution telemetry systems." Thesis, Nottingham Trent University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383304.
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Kim, Alisa [Verfasser]. "Deep Learning for Uncertainty Measurement / Alisa Kim." Berlin : Humboldt-Universität zu Berlin, 2021. http://d-nb.info/1227300824/34.
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Placido, Rui. "Estimating measurement uncertainty in the medical laboratory." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/11258.
Full textAbstract:
Medical Laboratories Accreditation is covered by ISO 15189:2012 - Medical Laboratories — Requirements for Quality and Competence. In Portugal, accreditation processes are held under the auspices of the Portuguese Accreditation Institute (IPAC), which applies the Portuguese edition (NP EN ISO 15189:2014). Accordingly, Medical Laboratories accreditation processes now require the estimate of measurement uncertainty (MU) associated to the results. The Guide to the Expression of Uncertainty in Measurement (GUM) describes the calculation of MU, not contemplating the specific aspects of medical laboratory testing. Several models have been advocated, yet without a final consensus. Given the lack of studies on MU in Portugal, especially on its application in the medical laboratory, it is the objective of this thesis to reach to a model that fulfils the IPAC’s accreditation regulations, in regards to this specific requirement. The study was based on the implementation of two formulae (MU-A and MU-B), using the Quality Management System (QMS) data of an ISO 15189 Accredited Laboratory. Including the laboratory’s two Cobas® 6000–c501 (Roche®) analysers (C1 and C2) the work focused three analytes: creatinine, glucose and total cholesterol. The MU-B model formula, combining the standard uncertainties of the method’s imprecision, of the calibrator’s assigned value and from the pre-analytical variation, was considered the one best fitting to the laboratory's objectives and to the study's purposes, representing well the dispersion of values reasonably attributable to the measurand final result. Expanded Uncertainties were: Creatinine - C1 = 9,60%; C2 = 5,80%; Glucose - C1 = 8,32%; C2 = 8,34%; Cholesterol - C1 = 4,00%; C2 = 3,54 %. ...[cont.].
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Trucíos, Caciano Ramón [Verfasser], Christoph [Akademischer Betreuer] Kleinn, Christoph [Gutachter] Kleinn, and Rivas José Javier [Gutachter] Corral. "Quantifying the uncertainty caused by sampling, modeling, and field measurements in the estimation of AGB with information of the national forest inventory in Durango, Mexico / Ramón Trucíos Caciano ; Gutachter: Christoph Kleinn, José Javier Corral Rivas ; Betreuer: Christoph Kleinn." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/121070272X/34.
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Lyn, Jennifer A. "Optimising uncertainty from sampling and analysis of foods and environmental samples." Thesis, University of Sussex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270732.
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Durisek, Nicholas Joseph. "Simultaneous overall measurement uncertainty reduction for multi-parameter macro-measurement system design /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487942739808246.
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Celebioglu, Emrah Hasan. "Developing A Computer Program For Evaluating Uncertainty Of Some Typical Dimensional Measuring And Gauging Devices." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605976/index.pdf.
Full textAbstract:
In dimensional measurements, it is required to specify uncertainty in the
measurement as the range of possible deviation for the measurement result. In this
thesis, a computer program is developed for evaluating uncertainty in
measurement of commonly used dimensional measuring devices like vernier
callipers, micrometers, comparators, and gauge blocks.
In evaluation of the uncertainty in measurement, some uncertainty sources
like temperature difference between the measured part and the instrument,
uncertainty in reference gauge block&rsquos dimension, mechanical effects, etc. are considered. The program developed, employs the EAL, NIST and GUM uncertainty evaluation equations as standard equations. However, the program can also be used for other measuring instruments and the users can define their own uncertainty equation. In the evaluations, for the standard uncertainty of the variables considered, symmetric distributions are used. The program gives the uncertainty budget and to compare the contribution of each variable on the overall uncertainty of the measurement, the uncertainty effect ratio is also given. In this thesis the evaluation process for uncertainty in measurement, the difference between the measurement error and uncertainty in measurement and the structure of the program are discussed. Also, a set of experiments has been made to illustrate the application of the program for evaluating the measurement uncertainty of vernier callipers with 1/50 and 1/20 resolutions, digital vernier calliper and 25 mm micrometer.