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"Uma aplicação industrial de regressão binária com erros na variável explicativa" / "An industrial application of binary regression with errors-in-variable explanatory"Favari, Daniel Fernando de 22 June 2006 (has links)
Neste trabalho, aplicamos um modelo de regressão binária com erros de medição na variável explicativa para analisar sistemas de medição do tipo atributo. Para isto, utilizamos o modelo logístico com erros na variável, para o qual obtemos as estimativas de máxima verossimilhança via o algoritmo EM e a matriz de informação de Fisher observada. Além disso, fizemos um estudo de simulação para compararmos o método analítico e os modelos logístico sem erros na variável (ingênuo) e logístico com erros na variável. Finalmente, aplicamos nossa metodologia para avaliarmos um sistema de medição passa/não passa da maior montadora de motores Diesel (MWM International). / In this work, we apply a study of binary regression model with errors-in-variable to analyze attributive measurement systems. For this, we use the logistic model with errors-in-variable to obtain parameter estimates of maximum likelihood through EM algorithm and the observed Fisher information matrix. In addition we do a simulation study to compare analytic method and the logistic model with and without measurement errors-in-variable. Finally, we apply our methodology to evaluate a attributive measurement system for the largest Diesel motor company of the world (MWM International).
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Multivariate skew-normal/independent distributions: properties and inference / Multivariate skew-normal/independent distributions: properties and inferenceLachos, Victor H., Labra, Filidor V. 25 September 2017 (has links)
Liu (1996) discussed a class of robust normal/independent distributions which contains a group of thick-tailed cases. In this article, we develop a skewed version of these distributions in the multivariate setting, and we call them multivariate skew normal/independent distributions. We derive several useful properties for them. The main virtue of the members of this family is that they are easy to simulate and lend themselves to an EM-type algorithm for maximum likelihood estimation. For two multivariate models of practical interest, the EM-type algorithm has been discussed with emphasis on the skew-t, the skew-slash, and the contaminated skew-normal distributions. Results obtained from simulated and two real data sets are also reported. / Liu (1996) discute una clase de distribuciones robustas a las que apela como normal/independiente, y que contiene un grupo de distribuciones de colas pesadas. En este artículo desarrollamos una versión asimétrica de tales distribuciones en un escenario multivariado, a las que llamaremos distruciones normales asimétricas independientes multivariadas. Para tales distribuciones derivamos algunas propiedades. La principal virtud de los miembros de esta familia es que son fáciles de simular y se prestan a un algoritmo de tipo EM para realizar estimaciones de máxima verosimilitud de sus parámetros. Para dos modelos multivariados de interés práctico se discute el algoritmo EM con énfasis en las distribuciones t-asimétrica, slash asimétrica y normal asimétrica contaminada. Los resultados obtenidos a partir de simulaciones y de dos conjuntos de datos reales son reportados.
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Identification à partir de mesures de champs : application de l'erreur en relation de comportement modifiée / Identification from full-field measurements : applying the modified constitutive relation error strategyBen Azzouna, Mouldi 12 July 2013 (has links)
La caractérisation des propriétés matérielles basée sur le dialogue essai-calcul requiert des précautions quant à la prise en compte des grandeurs physiques mises en jeu, aussi bien mesurées que calculées. Les mesures de champs cinématiques délivrent des informations qui permettent de rendre compte du comportement local du matériau et constituent une entrée riche pour ce type de dialogue axé sur la confrontation modèle - mesure. L’objet de ce travail est de discuter l’identification de propriétés élastiques homogènes ou hétérogènes, basée sur l’exploitation de mesures de champs, qui soulève la problématique de la prise en compte de mesures perturbées et d’hypothèses fortes de modélisation. Le but de cette étude est de discuter deux manières différentes pour aborder le problème. La première consiste à traiter les mesures en amont de l’étape d’identification, afin de filtrer les perturbations de mesures, et est basée sur l’outil d’approximation diffuse. La seconde consiste à développer une méthode d’identification inverse à partir d’essais quasi-statiques cherchant à tenir compte du caractère incertain des mesures, dès sa formulation, en utilisant l’ensemble des informations théoriques et expérimentales disponibles, en particulier en l’absence d’informations sur les conditions aux limites. Cette méthode est basée sur les principes de l’erreur en relation de comportement modifiée, amenant à résoudre des problèmes éléments finis non standards, et a conduit à mettre en œuvre des méthodes de résolution adaptées. L’étude a permis de souligner la robustesse de la méthode face aux incertitudes de mesure, notamment en comparaison avec le recalage par éléments finis. / The identification of material properties based on the confrontation between the experimental data and their numerical counterpart needs to pay special attention to their reliability and then to take some precautions. Especially, when dealing with full-field measurements which provide rich kinematic information enabling new possibilities for the characterization of material constitutive parameters. The aim of this work is to discuss the identification of the elastic parameters, for either homogeneous or heterogeneous materials, leading to the more general problem of the taking into account of noisy experimental data and strong model hypotheses. Two different approaches are addressed in this study. The first one consists in the processing of the experimental data upstream of the identification stage, by filtering them through a diffuse approximation algorithm. The second approach focuses on the development of an inverse identification strategy from static tests. This method takes into account the uncertainty of the measurements from the beginning of the formulation and is based on the modified constitutive relation error principles. It involves the resolution of non standard finite element problems using specific resolution methods. The study pointed out the robustness of the proposed method towards measurement errors, in particular when compared to the finite element model updating method.
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"Uma aplicação industrial de regressão binária com erros na variável explicativa" / "An industrial application of binary regression with errors-in-variable explanatory"Daniel Fernando de Favari 22 June 2006 (has links)
Neste trabalho, aplicamos um modelo de regressão binária com erros de medição na variável explicativa para analisar sistemas de medição do tipo atributo. Para isto, utilizamos o modelo logístico com erros na variável, para o qual obtemos as estimativas de máxima verossimilhança via o algoritmo EM e a matriz de informação de Fisher observada. Além disso, fizemos um estudo de simulação para compararmos o método analítico e os modelos logístico sem erros na variável (ingênuo) e logístico com erros na variável. Finalmente, aplicamos nossa metodologia para avaliarmos um sistema de medição passa/não passa da maior montadora de motores Diesel (MWM International). / In this work, we apply a study of binary regression model with errors-in-variable to analyze attributive measurement systems. For this, we use the logistic model with errors-in-variable to obtain parameter estimates of maximum likelihood through EM algorithm and the observed Fisher information matrix. In addition we do a simulation study to compare analytic method and the logistic model with and without measurement errors-in-variable. Finally, we apply our methodology to evaluate a attributive measurement system for the largest Diesel motor company of the world (MWM International).
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Koaxiální multiplexer pro automatizované měření AC proudu / Coaxial multiplexer for automatic measurement of AC currentBoštík, Ondřej January 2016 (has links)
Master’s thesis in the theoretical part deals with literature review on the topic of measurement errors and measurement uncertainties. The practical part deals with the simulation of additional capacitive and resistive load on the amplitude and phase error during shunts based measurement. For this simulation is used mathematical apparatus of cascade matrix of two-ports and their connections. For the actual simulation is used script for MATLAB. Furthermore, the work deals with the design of voltage follower to eliminate simulated errors and its practical realization. The last part deals with the design of the coaxial multiplexer for switching current shunts developed in the Czech Metrological Institute in Brno.
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A confirmatory factor analytic study of the aspects of identity questionnaire (AIQ-IV)Els, Leonie 09 February 2012 (has links)
To obtain valid and reliable research findings it is important to follow the process to validate measuring instruments. This entails determining the psychometric properties of a measure to eliminate or decrease the presence of measurement errors. Measurement errors have a negative impact on the validity of research findings. The aim of this study was to perform a confirmatory factor analytic study on the Aspects of Identity Questionnaire (AIQ-IV) to assess the model fit of the data. Confirmatory factor analysis was employed as part of the process to assess construct validity of a questionnaire to discover the misrepresenting influences of these measurement errors and to provide a foundation for further research. The AIQ-IV was administered to a sample of 157 participants in the South African context including different race, gender, age and occupation groups, drawn by means of convenient sampling. The research results and fit indices indicated that the data reflected a reasonable model fit. Copyright 2010, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Els, L 2010, A confirmatory factor analytic study of the aspects of identity questionnaire (AIQ-IV), MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02092012-122330 / > C12/4/67/gm / Dissertation (MCom)--University of Pretoria, 2010. / Human Resource Management / unrestricted
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Adaptive Reliability Analysis of Reinforced Concrete Bridges Using Nondestructive TestingHuang, Qindan 2010 May 1900 (has links)
There has been increasing interest in evaluating the performance of existing
reinforced concrete (RC) bridges just after natural disasters or man-made events
especially when the defects are invisible, or in quantifying the improvement after
rehabilitations. In order to obtain an accurate assessment of the reliability of a RC
bridge, it is critical to incorporate information about its current structural properties,
which reflects the possible aging and deterioration. This dissertation proposes to
develop an adaptive reliability analysis of RC bridges incorporating the damage
detection information obtained from nondestructive testing (NDT).
In this study, seismic fragility is used to describe the reliability of a structure
withstanding future seismic demand. It is defined as the conditional probability that a
seismic demand quantity attains or exceeds a specified capacity level for given values of
earthquake intensity. The dissertation first develops a probabilistic capacity model for
RC columns and the capacity model can be used when the flexural stiffness decays nonuniformly
over a column height. Then, a general methodology to construct probabilistic seismic demand models for RC highway bridges with one single-column bent is
presented. Next, a combination of global and local NDT methods is proposed to identify
in-place structural properties. The global NDT uses the dynamic responses of a structure
to assess its global/equivalent structural properties and detect potential damage locations.
The local NDT uses local measurements to identify the local characteristics of the
structure. Measurement and modeling errors are considered in the application of the
NDT methods and the analysis of the NDT data. Then, the information obtained from
NDT is used in the probabilistic capacity and demand models to estimate the seismic
fragility of the bridge. As an illustration, the proposed probabilistic framework is
applied to a reinforced concrete bridge with a one-column bent. The result of the
illustration shows that the proposed framework can successfully provide the up-to-date
structural properties and accurate fragility estimates.
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A Degradation-based Burn-in Optimization for Light Display Devices with Two-phase Degradation Patterns considering Warranty Durations and Measurement ErrorsGao, Yong January 2017 (has links)
No description available.
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Vad är god praxis för kalibrering och funktionskontroller av vågar inom läkemedelsindustrin / What is the best practice for calibration and routine testing of balances in the pharmaceutical industryGourie, Roberto January 2022 (has links)
I denna studie så ville AstraZenecas dispenseringsfunktion, som arbetar med att finfördelamaterial från sin bulkförpackning undersöka hur och med vilka frekvenser kalibreringar ochfunktionskontroller för deras vågar bör göras. Detta i hopp om att harmonisera en uppdateradoch förbättrad standard mellan siterna Gärtuna och Snäckviken. Standarder inom mätningslära är inget som läkemedelsföretag själva investerar resurser i, utanföljer det som farmakopéerna världen över publicerar i sina böcker. Däri återfinns allt som kantänkas behövas för tillverkning och utformning av läkemedel. Syftet med att kalibrera ochgenomföra funktionskontroller så ofta som AstraZeneca gör i dagsläget är för att vara förenligamed regelverk för att bli godkända vid inspektioner. Däremot finns risken attfunktionskontroller och kalibreringar genomförs med högre eller lägre frekvens än vad de bordegöras samt att irrelevanta tester vid dessa kontroller får alltför hög prioritering för att påvisa envågs förmåga att fungera som den ska. För att undersöka detta genomfördes det en kartläggning av hur AstraZeneca arbetar idag medvågkalibreringar och funktionskontroller. Denna behandlade både hur arbetet sker internt viaegna funktioner, men också externt via vågtillverkaren och valideringsfirmor. Dennainformation tillsammans med vad farmakopéerna och vågtillverkaren själva påstår är korrektarbetssätt blev ett tydligt och effektivt sätt att sålla bort överflödiga och i vissa fall irrelevantametoder som används på AstraZeneca idag. Utöver dessa finns det fenomen såsommätosäkerhet och störningselement som kan påverka varje vägning till den grad där resultatenär fullständigt missvisande, och i läkemedelsindustrins fall är dessa oacceptabla. Vid studiens slut kunde flera systematiska brister identifieras och rekommendationer för attmotverka eller lösa dessa gavs i enlighet med syftet om att nå god praxis för våganvändningen isamband med dispenseringsprocessen. Framtida förbättringsarbeten hade förenklats ocheffektiviserats till stor del om en fullständig digitalisering och övervakning avstörningselementen möjliggörs. / In this study that was commissioned by AstraZeneca's dispensing function that worksmainly by sub-dividing materials from its bulk packaging. They wanted to investigatehow and with what frequencies calibrations and routine testing for their balances shouldbe performed. This, with the purpose of harmonizing an updated and improvedstandard between the sites Gärtuna and Snäckviken. Measurement theory standards are not something that pharmaceutical companiesthemselves invest resources in but rather follow what pharmacopoeias around the worldpublish in their books. The books contain everything that may be needed for themanufacturing and design of medicines. The purpose of calibrating and performingroutine testing as often as AstraZeneca does today is to comply with regulations to beapproved during inspections. However, there is a risk that routine testing andcalibrations are performed at a higher or lower frequency than they should be, and thatirrelevant tests at these routine tests are given too high a priority to demonstrate abalances ability to function properly. To investigate this, a survey was conducted of how AstraZeneca works today withbalance calibrations and routine testing. The survey considered both how the work isdone internally via AstraZeneca’s own employees, but also externally via the balancemanufacturer and validation companies. This information, in combination with whatthe pharmacopoeias and the balance manufacturer themselves claim is the correct wayof operating, became a clear and effective way of sifting away superfluous and in somecases irrelevant methods used in AstraZeneca today. In addition to these, there arephenomena such as measurement uncertainty and external disturbance elements thatcan affect any weighing to the extent that the results are completely misleading, and inthe case of the pharmaceutical industry, such results would be unacceptable. At the end of the study, several systematic flaws or shortcomings could be identified andrecommendations to counteract or solve these were given in accordance with the aim ofachieving best practice for the use of balances in connection with the dispensingprocess. Future improvement work would have been greatly simplified and streamlinedif complete digitization and monitoring of the disturbance elements were made possible.
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