Measurement is an indispensable part of physical science as well as of commerce, industry, and daily life. Measuring activities appear unproblematic when performed with familiar instruments such as thermometers and clocks, but a closer examination reveals a host of epistemological questions, including: 1. How is it possible to tell whether an instrument measures the quantity it is intended to? 2. What do claims to measurement accuracy amount to, and how might such claims be justified? 3. When is disagreement among instruments a sign of error, and when does it imply that instruments measure different quantities? Currently, these questions are almost completely ignored by philosophers of science, who view them as methodological concerns to be settled by scientists. This dissertation shows that these questions are not only philosophically worthy, but that their exploration has the potential to challenge fundamental assumptions in philosophy of science, including the distinction between measurement and prediction. The thesis outlines a model-based epistemology of physical measurement and uses it to address the questions above. To measure, I argue, is to estimate the value of a parameter in an idealized model of a physical process. Such estimation involves inference from the final state (‘indication’) of a process to the value range of a parameter (‘outcome’) in light of theoretical and statistical assumptions. Idealizations are necessary preconditions for the possibility of justifying such inferences. Similarly, claims to accuracy, error and quantity individuation can only be adjudicated against the background of an idealized representation of the measurement process. Chapters 1-3 develop this framework and use it to analyze the inferential structure of standardization procedures performed by contemporary standardization bureaus. Standardizing time, for example, is a matter of constructing idealized models of multiple atomic clocks in a way that allows consistent estimates of duration to be inferred from clock indications. Chapter 4 shows that calibration is a special sort of modeling activity, i.e. the activity of constructing and testing models of measurement processes. Contrary to contemporary philosophical views, the accuracy of measurement outcomes is properly evaluated by comparing model predictions to each other, rather than by comparing observations.

Thesis (Ph.D.)--University of Western Australia, 2002.

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Graham, Samuel; Committee Member: Bassiri-Gharb, Nazanin; Committee Member: Doolittle, William A.; Committee Member: Garimella, Srinivas; Committee Member: Green, Dan; Committee Member: Sitaraman, Suresh. Part of the SMARTech Electronic Thesis and Dissertation Collection.

When a particle is illuminated by a beam of light it will scatter and redistribute the light in all directions. How it scatters depends on the size, shape and refractive index of the particle. Additionally, it depends on the wavelength and polarization of the illuminating beam. The direction and distance to the observer relative the particle also needs to be considered.  A digital holographic imaging system is used to collect parts of the scattered light from micrometer-sized particles. By utilizing digital holography a three-dimensional reconstruction of the imaged scene is possible. Traditionally, particles are localized based on the intensity in the holographic reconstructions. In this licentiate thesis, the phase response of the scattered light is investigated and utilized. An alternative method for locating spherical particles is presented. The method locate particles based on a simple feature of a propagating wave, namely the fact that the wavefront curvature changes from converging to diverging at the axial location of the particle. The wavefront curvature is estimated using two different methods. The first method estimates the lateral phase-gradients using a finite-difference method. The second method uses a three-dimensional parametric model based on a Chebyshev polynomial expansion. The methods are demonstrated using both simulations and experimental measurements. The simulations are based on the Lorenz-Mie scattering theory for spherical particles and are combined with an imaging system model. Experiments are performed using an off-axis polarization sensitive digital holographic system with a coherent Nd:YAG laser. Measurements of stationary particles are made to validate and evaluate the proposed method. It is found that these methods estimate the true axial position and does not have the offset that is associated with intensity-based methods. Additionally, it is possible to exclude noise that shows up as false particles since noise does not have the same phase response as a real particle. The second method, that uses a parametric model, also improves the standard deviation in the positioning.

[pt] O objetivo desta dissertação é apresentar os conceitos de Fator de Carga (FC) e Fator de Demanda (FD) e verificar o quanto estas informações estão atualizadas para uso pelas concessionárias de energia elétrica. A motivação pelo estudo resultou do fato de o conhecimento e o gerenciamento desses índices proporciorem maior eficiência e segurança às instalações e equipamentos, além de permitir redução do custo da energia elétrica. A metodologia utilizada para o cálculo se baseia nos testes de Chauvenet, que permite determinar se um valor amostral (resultante de uma medição) é anômalo (outlier) em relação aos restantes valores da amostra, supondo-se que esta amostra é retirada de uma distribuição normal. Dentre os principais resultados destacam-se estimativas do Fator de Carga e Fator de Demanda, típicos para os diversos segmentos de clientes de uma empresa de distribuição de energia elétrica. Para se obter essas estimativas foi realizada uma pesquisa de campo permitindo o levantamento da potência instalada em clientes atendidos na alta e na baixa tensão. Em paralelo à pesquisa de campo, a concessionária de energia elétrica realizou medições de consumo e demanda junto a esses clientes. Como conclusão o trabalho confirma que as distribuidoras de energia elétrica não possuem acesso a um cadastro atualizado da potência instalada de seus consumidores. Faz-se necessário uma atualização mais dinâmica nas bases de dados disponíveis o que permitiria uma estimativa mais precisa dos fatores de carga e de demanda. / [en] The aim of this work discusses basic concepts associated with the load factor (LF) and demand factor (DF) and the adequacy of their use by electricity utilities. The knowledge and management of these electrical parameters is rather important, as they contribute for the improvement of the efficiency and security of the system as a whole while promoting reduction on energy costs. The method used to estimate these quantities is based on the Chauvenet statistical tests capable to detect and remove possible discontinuity on the sample data observed to follow normal distribution. The LD and DF were estimated for various clusters of similar clients of a given distributing utility. Estimations were obtained through a survey involving clients of the selected utility to capture information on the end-users and their nominal power demanded at both, the low and high voltage levels. In parallel to the survey, the utility measured and monitored the energy consumption of the clients participating in the study. As a conclusion, the study revealed that the electricity utilities do not have access to update information (stratified by segments of clients) on the electrical parameters. A dynamic scheme to make available updated information related to load factor and demand factor proved to be extremely useful and is highly recommended.

OBJECTIVE: To explore a novel virtual inspection approach with a 3D metrology software to provide a non-destructive in situ analysis in digital workflow. Also, to evaluate the fit discrepancies of lithium disilicate crowns by using such a novel virtual measuring technique. MATERIALS AND METHODS: Maxillary arch typodont was used to design abutment for tooth #8 and #14 (hand prepared) and #4 and #10 (titanium custom abutment). All four abutments were placed into a duplicated maxillary arch solid stone model for scanning with laboratory scanner. Four crown patterns were designed and exported as STL files. The internal control group consists of the four original digital STL files and the external control group which was the 32-milled lithium disilicate crowns (IPS e.max® CAD, Ivoclar Vivadent, Inc.), eight patterns for each tooth. Thirty-two pressable wax patterns (8 of each) was fabricated for each of the three different technique systems. Two printed wax systems, Varseo Wax CAD/Cast (BEGO) and Press-E-Cast (EnvisionTec). Two milled wax systems Harvest Wax (Ivoclar Vivadent, Inc.) and Polycon Cast (Straumann), and a set of conventional cutbacks of 1.5mm with applied marginal wax. All patterns were pressed into lithium disilicate crowns, then fine polished and scanned. Each file was imported into a quality control metrology software (Geomagic Control X, 3D Systems) for marginal fit and internal fit evaluation with respective digital abutment. RESULTS: Mean of marginal gap for all groups were all lower than the preset gap space of 40 microns. Statistically significant differences in the fit accuracy were found among tooth number, technique system and measurement locations, but the differences are in clinically acceptable range. New scope of analyzing a restoration in a 3D fashion can help solve clinical complications. The study has shown that lower marginal gap does not necessary indicates a better fit restoration, as every level of the crown should be evaluated for. CONCLUSION: This novel inspection method can be used as a replacement of fit checker and help clinician to work in a full digital workflow. Lithium disilicate restorations fabricated through printed wax pattern, milled wax pattern and conventional hand wax are all clinically acceptable techniques. / 2019-09-26T00:00:00Z

Le système nerveux central humain est un système de traitement de l'information stupéfiant en termes de capacités, de polyvalence, d’adaptabilité et de faible consommation d'énergie. Sa structure complexe se compose de milliards de neurones, interconnectés par plusieurs trillions de synapses, formant des grappes spécialisées. Récemment, l'imitation de ces paradigmes a suscité un intérêt croissant en raison de la nécessité d'approches informatiques avancées pour s'attaquer aux défis liés à la génération de quantités massives de données complexes dans l'ère de l’Internet des Objets (IoT). Ceci a mené à un nouveau domaine de recherche, connu sous le nom d’informatique cognitive ou d'ingénierie neuromorphique, qui repose sur les architectures dites non-von-Neumann (inspirées du cerveau) en opposition aux architectures von-Neumann (ordinateurs classiques). Dans cette thèse, nous examinons l'utilisation des technologies de mémoire résistive telles que les mémoires à accès aléatoires à base de lacunes d’oxygène (OxRAM) et les mémoires à pont conducteur (CBRAM) pour la conception de synapses artificielles, composants de base indispensables des réseaux neuromorphiques. De plus, nous développons un réseau de neurones impulsionnels artificiel (SNN), utilisant des synapses OxRAM, pour l'analyse de données impulsionnelles provenant du cerveau humain en vue du traitement de troubles neurologiques, en connectant la sortie du SNN à une interface cerveau-ordinateur (BCI). L'impact des problèmes de fiabilité, caractéristiques des OxRAMs, sur les performances du système est étudié en détail et les moyens possibles pour atténuer les pénalités liées aux incertitudes des dispositifs seuls sont démontrés. En plus de l’implémentation avec des OxRAMs et CBRAMs de la bien connue plasticité fonction du temps d’occurrence des impulsions (STDP), qui constitue une forme de plasticité à long terme (LTP), les dispositifs OxRAM ont également été utilisés pour imiter la plasticité à court terme (STP). Les fonctionnalités fondamentalement différentes de la LTP et STP sont mises en évidence. / The central nervous system of humankind is an astonishing information processing system in terms of its capabilities, versatility, adaptability and low energy consumption. Its complex structure consists of billions of neurons interconnected by trillions of synapses forming specialized clusters. Recently, mimicking those paradigms has attracted a strongly growing interest, triggered by the need for advanced computing approaches to tackle challenges related to the generation of massive amounts of complex data in the Internet of Things (IoT) era. This has led to a new research field, known as cognitive computing or neuromorphic engineering, which relies on the so-called non-von-Neumann architectures (brain-inspired) in contrary to von-Neumann architectures (conventional computers). In this thesis, we explore the use of resistive memory technologies such as oxide vacancy based random access memory (OxRAM) and conductive bridge RAM (CBRAM) for the design of artificial synapses that are a basic building block for neuromorphic networks. Moreover, we develop an artificial spiking neural network (SNN) based on OxRAM synapses dedicated to the analysis of spiking data recorded from the human brain with the goal of using the output of the SNN in a brain-computer interface (BCI) for the treatment of neurological disorders. The impact of reliability issues characteristic to OxRAM on the system performance is studied in detail and potential ways to mitigate penalties related to single device uncertainties are demonstrated. Besides the already well-known spike-timing-dependent plasticity (STDP) implementation with OxRAM and CBRAM which constitutes a form of long term plasticity (LTP), OxRAM devices were also used to mimic short term plasticity (STP). The fundamentally different functionalities of LTP and STP are put in evidence.

[pt] O objetivo da dissertação é analisar a importância dos mecanismos da avaliação da conformidade para o agronegócio sustentável do café verde, tendo em vista a proposição de recomendações para os pequenos cafeicultores da Guatemala. As oportunidades de segmentação e diferenciação que se abrem para os produtos agroindustriais, dentre eles o café, estão entre os fatores mais relevantes que vem influenciando a sustentabilidade dos agronegócios. Nesse contexto, um dos impactos positivos da diferenciação no mercado de café verde é o fortalecimento da posição competitiva dos pequenos cafeicultores nessa cadeia agroindustrial. A motivação da pesquisa é destacar os benefícios da avaliação da conformidade e, em particular, de seu mecanismo de certificação, para os pequenos cafeicultores da Guatemala, na perspectiva da adoção de boas práticas agrícolas, da rastreabilidade e do cumprimento dos padrões internacionais já aceitos no agronegócio de café verde. A metodologia compreende: (i) pesquisa bibliográfica sobre métodos de avaliação de sustentabilidade agrícola, boas práticas agrícolas (BPA), normalização, rastreabilidade e avaliação da conformidade aplicadas a agronegócios sustentáveis; (ii) descrição das práticas internacionais para o agronegócio do café verde; (iii) descrição dos panoramas internacional e guatemalteco do agronegócio em foco; (iv) estudo de caso sobre a Fedecocagua, uma federação de pequenos produtores de café da Guatemala, e três de suas cooperativas; (v) formulação de recomendações para os pequenos produtores de café verde daquele país, à luz das práticas internacionais e da iniciativa brasileira de produção integrada do café (PIC). Destacam-se como resultados: (i) visão global das condições competitivas do agronegócio do café verde em nível mundial e na Guatemala; (ii) mapeamento dos modelos de cafeicultura sustentável; e (iii) diagnóstico situacional da Fedecocagua e de três de suas cooperativas conforme as grades analíticas desta pesquisa. Como conclusão, o trabalho identifica práticas internacionais que podem ser integradas em um código de conduta mínimo para o agronegócio sustentável do café verde da Guatemala. / [en] The main objective of this dissertation is to analyze the importance of conformity assessment mechanims within agribusiness context, with the view of proposing a set of recommendations for small-scale coffee growers from Guatemala. The increasing demand for healthy and social and environmentally-sound products have fostered the presence of these attributes in food products worldwide. Focusing on green coffee agribusiness, the scope of differentiation and quality concept should encompass social and environmental concerns, such as the adoption of sustainable productive systems and labor conditions under which coffee is grown, besides physical and sensorial characteristics of final product. In this context, a positive social and economical impact of differentiation in coffee market is the possibility to strengthen the position of small coffee growers in the production chain. The motivation for carrying out this research is to identify potential benefits of applying quality management and conformity assessment practices in the context of small-scale coffee growers from Guatemala, within the perspective of their continuous improvement in adopting Good Agricultural Practices (GAP), traceability procedures and their compliance with international standards already accepted by green coffee agribusiness markets, at regional and international levels. The methodology encompasses: (i) bibliographical review on methods to assess agricultural sustainability, good agricultural practices (GAP), and infrastructural technologies, more specifically standardization, traceability and conformity assessment, including certification; (ii) international practices survey concerning green coffee agribusiness, (iii) international and Guatemalan outlooks of coffee agribusiness; (iv) case study on Fedecocagua, a federation of small-scale coffee growers from Guatemala, and three of its cooperatives; (v) formulation of recommendations for small-scale coffee growers from that country, in the light of international practices and also from the experience accumulated by the Program on Coffee Integrated Production (CIP), which has been carried out in Brazil. The main results can be summarized as follows: (i) an overview of competitive drivers of green coffee agribusiness, at international and Guatemalan levels; (ii) mapping models of sustainable coffee production; and (iii) situational diagnosis of Fedecocagua according to the analytical framework designed for this research. As a conclusion, this dissertation identifies some international sustainable practices which could be integrated in a minimal conduct code concerning green coffee agribusiness in Guatemala. / [es] El objetivo de la disertación es analizar la importancia de la evaluación de la conformidad en el agronegocio del café verde sostenible, en vista de una propuesta de recomendaciones para los pequeños productores de café de Guatemala. Las oportunidades de segmentación y de diferenciación que se abren para los productos agroindustriales, entre ellos el café, están entre los factores más relevantes que vienen influenciando a la sustentabilidad en los agronegocios. En consecuencia, algunos atributos de la calidad, susceptibles de certificación, están siendo agregados como instrumentos de competencia del producto final. La creciente demanda, en particular en países desarrollados, por productos saludables, ambientalmente y socialmente aceptados, que posibilitan la incorporación de nuevos atributos de calidad. En ese contexto, uno de los impactos positivos de la diferenciación en el mercado del café verde, es la posibilidad de fortalecer el posicionamiento competitivo de los pequeños productores de café en Guatemala, en esta cadena agroindustrial. La motivación de la investigación es destacar los beneficios que tiene la evaluación de la conformidad, en forma particular su mecanismo de certificación, para pequeños productores de café verde de Guatemala, en la perspectiva de la adopción de buenas prácticas agrícolas, de la trazabilidad y del cumplimiento de las normas internacionales aceptadas en el agronegocio de café verde. La metodología comprende: (i) investigación bibliográfica sobre buenas prácticas agrícolas, normalización, trazabilidad y evaluación de la conformidad aplicadas a los agronegocios sostenibles; (ii) descripción de las practicas internacionales para el agronegocio de café verde; (iii) descripción de los panoramas internacionales y guatemalteco del agronegocio en estudio. (iv) estudios de casos múltiples, comprendiendo a la Fedecocagua, una federación de pequeños productores de café de Guatemala, y tres de sus cooperativas; (v) formulación de recomendaciones para los pequeños productores de café de aquel país, a la luz de las prácticas internacionales y de la experiencia brasileña de la producción integrada de café (PIC). Se destacan como resultados: (i) visión global de las condiciones competitivas del agronegocio del café verde a nivel mundial y en Guatemala; (ii) descripción de los modelos de caficultora sostenible; (iii) diagnóstico situacional de la Fedecocagua y de tres de sus cooperativas conforme el marco analítico de la investigación. Como conclusión, el trabajo identifica prácticas internacionales que pueden ser integradas en un código de conducta mínimo para el agronegocio sostenible del café verde en Guatemala.

Esta dissertação aborda a implantação de um guia orientativo de incerteza de medição aplicável aos avaliadores de laboratório da Rede Metrológica RS. A incerteza de medição é um importante tema para organismos de avaliação de laboratórios, como é o caso da Rede Metrológica RS, pois consiste em um dos requisitos básicos para o reconhecimento de competência de laboratórios. Dessa forma, é fundamental garantir que todos os avaliadores possuam um nível de conhecimento adequado sobre incerteza de medição. Assim, o objetivo principal deste trabalho consiste em implantar o referido guia orientativo de incerteza, propiciando melhorias no processo de avaliação da Rede Metrológica RS. Adicionalmente, foi elaborado um fluxograma explicativo dos passos para a expressão da incerteza de medição, assim como listadas componentes de incerteza típicas para áreas de ensaio e calibração e elaborada uma check-list para auxílio aos avaliadores quando da avaliação da incerteza. A implantação do guia orientativo de incerteza dos avaliadores foi realizada segundo as etapas do ciclo de melhoria PDCA. Na etapa plan foram coletados dados que corroboraram para uma necessidade de maior qualificação do grupo de avaliadores com relação à incerteza, sendo a área de ensaios a mais carente. Na etapa do, a minuta do documento foi elaborada de acordo com tópicos previamente definidos com um grupo de especialistas, que envolveu avaliadores experientes e membros da Rede Metrológica RS, assim como especialistas em incerteza do Inmetro. Na etapa check, a minuta do documento passou pela análise crítica do grupo de especialistas consultados e na etapa act foram realizados os ajustes finais e aprovado o documento. Como resultado, foi evidenciada a melhoria do nível de conhecimento dos avaliadores com relação ao tema. Tal fato pôde ser comprovado através da aplicação de provas antes e após o treinamento no novo documento elaborado, mostrando melhoria dos conhecimentos dos avaliadores com relação à incerteza. / This work is concerned with the implantation of a measurement uncertainty guideline applicable to Rede Metrológica RS' assessors. Measurement uncertainty is a quite relevant subject for all laboratory assessment bodies, such as Rede Metrológica RS, because it consists in an elementary requirement for laboratory competence recognition. Thus, it is essential to assure that all assessors have an adequate level of knowledge about measurement uncertainty. Therefore, the main objective of this work consists in the implantation of the referred guideline, yielding improvements on Rede Metrológica RS' assessment process. Additionally, a flow-chart was elaborated to help assessors better understand the procedure to the expression of uncertainty in measurement. A list of common uncertainty sources in calibration and testing fields was prepared, as well as a check-list to help assessors carry out measurement uncertainty assessment. The guideline implementation was carried out following the steps of PDCA improvement cycle. During the step 'plan', some data were collected that corroborated the identified need for better qualification of assessors with respect to measurement uncertainty theory and application. The most deficient field identified was testing assessors. On 'do' step, a guideline draft was prepared in accordance with the topics previously agreed with a group of experts, formed by experienced assessors and Rede Metrológica RS' collaborators, as well as, invited uncertainty experts from Inmetro. On the step 'check', the guideline draft was analyzed by the same group of experts and during the step act, the final adjustments were made and the guideline was formally approved. As a result, an improvement on the assessors' level of knowledge concerning measurement uncertainty was achieved. This was possible to verify by applying assessors' written exams about measurement uncertainty, before and after the training on the new guideline. The exams showed the improvement of the assessors.

Over the last few decades, quantised excitations of the electromagnetic field have proven to be an ideal system with which to investigate and harness quantum optical phenomena. The techniques developed have enabled fundamental tests of quantum mechanics as well as practical applications in quantum metrology and quantum information processing. Advancing to larger-scale entangled quantum systems will open up new regimes of quantum many-body physics, allowing us to probe the limits of quantum mechanics and enabling truly quantum-enhanced technologies. However, moving towards this goal will require further experimental and theoretical innovations. The work described in this thesis focuses on several different aspects of optical quantum information, but are ultimately all linked by this long-term aim. The first part of this thesis describes a novel method for strain-based active control of quantum optical circuits and a new method for the characterisation of high efficiency detectors. Building on this, I discuss in detail two different fields of quantum optics that stand to benefit from these techniques. I initially consider quantum-enhanced metrology, including work aimed towards demonstrating a truly better-than-classical phase measurement, and a theoretical exploration of multiple-phase estimation. Finally, I focus on linear-optical quantum information processing, exploring in detail the use of time-frequency encodings for quantum computing.