Dissertations / Theses on the topic 'Metrology'
To see the other types of publications on this topic, follow the link: Metrology.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Metrology.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
SILVA, PEDRO PAULO ALMEIDA. "METROLOGY IN STANDARDS, STANDARDS IN METROLOGY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4049@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORA presente dissertação de mestrado intitulada Metrologia nas normas, normas na metrologia foi motivada por recomendações explícitas contidas no Plano Nacional de Metrologia (PNM) - transformado em instrumento da política metrológica brasileira, por força de Resolução Interministerial do CONMETRO, que propôs ações de fortalecimento do sistema brasileiro de normalização, priorizando a implementação de um comitê brasileiro para normalização em metrologia na estrutra orgânica da ABNT. Entendidas como funções complementares da tecnologia industrial, metrologia e normalização são tratadas não apenas como insumos essenciais para desenvolvimento da competitividade industrial e melhoria da qualidade de vida, mas, também, como elementos indissociáveis no equacionamento de vulnerabilidades que restringem o acesso de produtos brasileiros a mercados competitivos em decorrência de barreiras técnicas ao comércio internacional. Assim, no contexto das recomendações apontadas pelo PNM, a pesquisa de mestrado contemplou: (i) estudo do modus operandi dos organismos internacionais de normalização, para se perceber a forma pela qual o insumo metrológico é agregado às normas internacionais; (ii) análise das práticas vivenciadas por organismos nacionais de normalização de países mais industrializados, objetivando apreender suas experiências no desenvolvimento de normas em metrologia; (iii) entrevista junto a especialistas atuantes em metrologia e em normalização, objetivando definir um padrão de atuação para se equacionar a normalização técnica setorial no Brasil; (iv) caracterização dos principais fatos marcantes que impactaram o alavancamento da normalização técnica no País, provendo subsídio para equacionamento dos óbices ainda existentes e (v) análise das carências e vulnerabilidades do sistema brasileiro de normalização, assim consolidando conhecimento e uma visão crítica para planejamento da pesquisa de mestrado que se constituiu na concepção e formulação das bases conceituais de um comitê técnico para normalização em metrologia, proposto para ser implementado na estrutura orgânica da ABNT, entendido como estratégia de fortalecimento do sistema brasileiro de normalização e (vi) pesquisa de demanda por normalização em metrologia. Objetivando diferenciar as demandas por normalização em metrologia das demandas por metrologia na normalização, a pesquisa foi desenvolvida no contexto de três ambientes: (a) junto aos comitês brasileiros de normalização (ABNT/CB) e organismos de normalização setorial (ONS) que integram a estrutura orgânica da Associação Brasileira de Normas Técnicas (ABNT), com o propósito de conhecer necessidades específicas de metrologia na atividade de normalização bem como as dificuldades relacionadas ao uso e aplicação de fundamentos da metrologia como insumo ao processo de normalização técnica; (b) junto a especialistas de metrologia e normalização, para subsidiar o desenvolvimento de uma interface técnica de cooperação e (c) junto a fóruns especialistas de metrologia, para se identificar demandas por normalização, identificadas ao longo das respectivas cadeias hierárquicas de disseminação das unidades de base e derivadas do Sistema Internacional de Unidades (SI). Adicionalmente às bases de dados (caracterização de demandas por normalização em metrologia) que foram consolidadas pelo presente trabalho e que levaram à ampla reflexão sobre a correlação existente entre metrologia nas normas e normas na metrologia, destacam-se os seguintes resultados que também emergiram da presente dissertação de mestrado: (i) desenvolvimento de uma nova área de concentração em normalização técnica, criada no Programa de Pós- Graduação em Metrologia da PUC-Rio; (ii) indução de um processo para geração de conhecimento e formação de recursos humanos em normalização; (iii) a recente cri
The present master s degree dissertation entitled Metrology in standards, standards in metrology was motivated by explicit recommendations included in the National Metrology Plan (PNM) - which became an instrument of the Brazilian metrology policy, by force of a Interministerial Decision from CONMETRO, that had proposed specific actions to strenghten the Brazilian system of standardization, prioritizing the implementation of a technical committe for standardization in metrology within the ABNT structure. As complementary functions of industrial technology, metrology and standardization are treated not only as essential inputs necessary for the development of industrial competitiveness and quality of life enhancement, but also as intrinsic elements in equating vulnerabilities which restrict access of Brazilian products to competitive markets because of technical barriers to international trade. Thus, within the context of recommendations made by PNM, this master s degree research considered: (i) a study of the modus operandi of international standardization organizations, so as to perceive the way through which metrology inputs are added to international standards; (ii) an analysis of practices by national standardization organizations in industrialized countries so as to capture their experience in developing metrology standards; (iii) interviews with active experts in metrology and standardization with the purpose of defining a performance pattern in order to equate technical standards of industry in Brazil; (iv) a description of the most outstanding facts which had an impact on leveraging technical standardization in the country, providing subsidies to equate existingobstacles; (v) an analysis of the shortages and vulnerabilities of the Brazilian standardization system, thus consolidating knowledge and a critical vision in order to plan this master s dissertation which consisted of conceiving and formulating the conceptual fundamentals of a technical committee for standardization in metrology, to be implemented in ABNT s organic structure, as a strategy to enhance the Brazilian standardization system, and (vi) standardization demand research in metrology. With the aim of distinguishing the demand for standardization in metrology from the demand for metrology in standardization, this research was developed along three different lines: (a) at Brazilian standardization committees (ABNT/CB) and industry standardization organizations (ONS) which make up the organic structure of the Brazilian Association for Technical Standards (ABNT), so as to know the specific needs for metrology in standardization activities, as well as, the difficulties related to the use and application of metrology fundamentals as inputs to the technical standardization process; (b) with metrology and standardization experts in order to subsidize the development of the interface of a new cooperation rationale, and (c) research in forum specialized in metrology so as to identify standardization demands, pointed out throughout respective dissemination hierarchical chains of base units and derived from the International System of Units (SI). In addition tothe data bank which was consolidated by study and research developed and which led to a broad reflection on the existing correlation between metrology in standards and standards in metrology, the following results, which also came out of this master s degree dissertation, can be highlighted: (i) development of a new concentration area in technical standardization, created for the Post Graduate Program in Metrology at the Catholic University (PUC-Rio) in Rio de Janeiro; (ii) introduction of a process to build knowledge and development of human resources in standardization; (iii) the recent creation of ABNT/CB-53, the Brazilian Committee for Standardization in Metrology, whose genesis, conception, framework and implementation came out of the current master s degree work in metrology and which, officially , supplies Brazilian society with a technical forum for standardization in metrology. This d
2
TONA, ANDREA. "Thermoelectric Metrology." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2546136.
Full textAbstract:
Metrology, the science of measure, is in constant evolution and development in every field. Recently, due to the energy problem, some physical effect and related device are receiving new attention, in particular: piezoelectricity and thermoelectricity.
We think that the time is ripe to expand the science of measure in a new may:Thermoelectric Metrology.
This work represent a new beginning in this field: we study and build a new method and instrument to measure the figure of merit zT and
Resistance R, also we describe a new way to use thermoelectric device (in particular Peltier cells), to apply linear system theory and frequency analysis to measure thermo-physical property such as thermal effusivity and thermal diffusivity.
3
Tell, Eric, and Alexander Ökvist. "SMART MANUFACTURING AND METROLOGY : How can metrology enable smart manufacturing?" Thesis, KTH, Industriell produktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244837.
Full textAbstract:
To create the possibilities needed for more precise simulations and calculations regarding manufacturing changes in the equipment and new technology has to be implemented. This work investigates possible solutions for the gathering of information in manufacturing companies. To get a wider understanding of the current situation in manufacturing we have also researched some possible solutions and applications that can be applied in manufacturing. The work consists of a literature study regarding the possible solutions and technologies of smart manufacturing complemented by a survey and a follow-up interview with scientist and employees’ at large corporations to get their view of the business today and possibilities for the future. The benefits from a successful implementation of metrology can help companies toward success in the transformation toward smart manufacturing. This report also investigates what is needed for implementing smart manufacturing and the transformation in manufacturing companies to get economic advantages with a technological adaption. It also covers the possible difficulties and problems that may occur when this implementation is performed.Vid skapandet av grunder för att möjliggöra beräkningar och simulering för produktion så finns det krav på att nya verktyg och ny teknik implementeras. Detta arbete undersöker möjliga lösningar för att samla in information i industriella företag samt hur dessa företag ska gå tillväga för att möjliggöra denna omställning. För att få en bättre förståelse för området har vi även undersökt några möjliga applikationer som kan implementeras inom industrin. Arbetet består av en litteraturstudie där vi undersökte området smart manufacturing samt möjliga lösningar och tekniker som krävs för att uppnå detta. Som komplement till detta skapades även en enkät som baserades på området, svaren från enkäten följdes upp av intervjuer med deltagarna. Deltagarna var särskilt utvalda personer på större industriföretag eller institutioner vilka hade erfarenheter inom området metrologi. Detta användes som utökad grund för att få både en uppfattning av dagsläget samt idéer inför framtiden. Fördelarna med en lyckad implementering av metrologi kan hjälpa företag att ta steget mot att applicera smart manufacturing i deras produktion. Detta kan möjliggöra enklare produktion för operatörer men även ekonomiska fördelar för företaget i helhet. Arbetet tar även upp möjliga problem eller svårigheter som kan ske under denna implementation
4
Gendra, Casalí Bernat. "Probabilistic quantum metrology." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/371132.
Full textAbstract:
La Metrologia és el camp d’investigació sobre les eines estadístiques i el disseny tecnològic dels aparells de mesura necessaris per inferir informació precisa sobre paràmetres físics. En un sistema físic el soroll és inherent en última instància amb el de les seves parts, i per tant en un nivell microscòpic està governat per les lleis de la física quàntica. Les mesures quàntiques són intrínsecament sorolloses i per tant limiten la precisió amb la qual es pot obtenir en qualsevol escenari de metrologia. El camp de la metrologia quàntica està dedicat a l’estudi d’aquests límits i al desenvolupament de noves eines per ajudar a superar-los, sovint fent ús de les característiques exclusivament quàntiques com la superposició o l'entrellaçament.En el procés de disseny d’un protocol d’estimació és necessari utilitzar una figura de mèrit per optimitzar el rendiment d’aquests protocols. Fins ara la majoria de plantejaments de metrologia quàntica i els límits que en deriven han estat deterministes, és a dir, que estan optimitzats per tal de proporcionar una estimació vàlida per a cadascun dels possibles resultats de la mesura i minimitzar-ne l’error promig entre el valor estimat i el real del paràmetre. Aquesta avaluació dels protocols mitjançant el seu error promig és molt natural i convenient, però pot haver-hi algunes situacions en què això no sigui suficient per a expressar l’ús concret que se li donarà al valor obtingut.Un punt central d’aquesta tesi és observar que resultats concrets d’una mesura poden proporcionar una estimació amb una millor precisió que la mitjana. Perquè això succeeixi hi ha d’haver altres resultats imprecisos que compensin la mitjana perquè aquesta no violi els límits deterministes. En aquesta tesi hem escollit una figura de merit que reflecteix la màxima precisió que es pot obtenir. Optimitzem la precisió d’un subconjunt de resultats senyalats, i quantifiquem la probabilitat d’obtenir-ne algun d’ells, o en altres paraules, la probabilitat que el protocol proporcioni una estimació. Això pot ser entès com proposar una opció addicional que està sempre disponible per la mesura, a saber, la possibilitat de post-seleccionar els resultats i donar amb només certa probabilitat una resposta concloent. Aquests protocols probabilístics garanteixen una precisió mínima pels resultats senyalats. En la mecànica quàntica hi ha moltes maneres de poder llegir les dades d’un sistema quàntic. Per tant, l’optimització dels esquemes probabilístics no es pot reduir a la reinterpretació de resultats a partir dels esquemes (determinsitic) de metrologia quàntica canòniques, sinó que implica la recerca de mesures quàntiques completament diferents. Concretament, hem dissenyat protocols probabilístics per a l’estimació de fases, direccions i de sistemes de referència. Hem vist que la post-selecció té dos efectes possibles: compensar una mala elecció de l’estat inicial o contrarestar els efectes negatius del soroll presents en l’estat del sistema o en el procés de mesurament. En particular, trobem que afegir la possibilitat d’abstenció en l’estimació de fases en presència de soroll pot produir una millora en la precisió que supera la cota trobada per protocols deterministes. Trobem una cota que correspon a la millor precisió que es pot obtenir.Metrology is the field of research on statistical tools and technological design of measurement devices to infer accurate information about physical parameters. The noise in a physical setup is ultimately related to that of its constituents, and at a microscopic level this is in turn dictated by the rules of quantum physics. Quantum measurements are inherently noisy and hence limit the precision that can be reached by any metrology scheme. The field of quantum metrology is devoted to the study of such limits and to the development of new tools that help to surmount them, often make use unique quantum features such as superposition or entanglement. In the process of designing an estimation protocol, the experimentalist uses a figure of merit to optimise the performance of such protocols. Up until now most quantum metrology schemes and known bounds have been deterministic, that is, they are optimized in order to provide a valid estimate for each possible measurement outcome and minimize the average error between the estimated and true value of the parameter. This benchmarking of a protocol by its average performance is very natural and convenient, but there can be some scenarios in which this is not enough to express the concrete use that will be given to the obtained value. A central point in this thesis is that particular measurement outcomes can provide an estimate with a better precision than the average one. Notice that for this to happen there must be other imprecise outcomes so that the average does not violate the deterministic bounds. In this thesis we choose a figure of merit that reflects the maximum precision one can obtain. We optimise the precision of a set of heralded outcomes, and quantify the chance of such outcomes to occur, or in other words the probability that the protocol fails to provide an estimate. This can be understood as putting forward an extra feature that is always available to the experimentalist, namely the possibility of post-selecting the outcomes of their measurements and giving with some probability an inconclusive answer. These probabilistic protocols guarantee a minimal precision upon a heralded outcome. In quantum mechanics there are many ways in which data can be read-off from a quantum system. Hence, the optimization of probabilistic schemes cannot be reduced to reinterpreting results from the canonical (determinsitic) quantum metrology schemes, but rather it entails the search of completly different quantum generalized measurements. Specifically, we design probabilistic protocols for phase, direction and reference frame estimation. We show that post-selection has two possible effects: to compensate a bad choice of probe state or to counterbal¬ance the negative effects of noise present in the state system or in the measurement process. In particular, we show that adding the possibility of abstaining in phase estimation in presence of noise can produce an enhancement in precision that overtake the ultimate bound of deterministic protocols. The bound derived is the best precision that can be obtained, and in this sense one can speak of ultimate bound in precision.
5
Fieß, Markus. "Advancing attosecond metrology." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-119134.
Full text
6
O'Mara, David Thomas John. "Automated facial metrology." University of Western Australia. School of Computer Science and Software Engineering, 2002. http://theses.library.uwa.edu.au/adt-WU2003.0015.
Full textAbstract:
Automated facial metrology is the science of objective and automatic measurement of the human face. There are many reasons for measuring the human face. Psychologists are interested in determining how humans perceive beauty, and how this is related to facial symmetry [158]. Biologists are interested in the relationship between symmetry and biological fitness [124]. Anthropologists, surgeons, forensic experts, and security professionals can also benefit from automated facial metrology [32, 101, 114]. This thesis investigates the concept of automated facial metrology, presenting original techniques for segmenting 3D range and colour images of the human head, measuring the bilateral symmetry of n-dimensional point data (with particular emphasis on measuring the human head), and extracting the 2D profile of the face from 3D data representing the head. Two facial profile analysis techniques are also presented that are incremental improvements over existing techniques. Extensive literature reviews of skin colour modelling, symmetry detection, symmetry measurement, and facial profile analysis are also included in this thesis. It was discovered during this research that bilateral symmetry detection using principal axes is not appropriate for detecting the mid-line of the human face. An original mid-line detection technique that does not use symmetry, and is superior to the symmetry-based technique, was developed as a direct result of this discovery. There is disagreement among researchers about the effect of ethnicity on skin colour. Some researchers claim that people from different ethnic groups have the same skin chromaticity (hue, saturation) [87, 129, 206], while other researchers claim that different ethnic groups have different skin colours [208, 209]. It is shown in this thesis that people from apparently different ethnic groups can have skin chromaticity that is within the same Gaussian distribution. The chromaticity-based skin colour model used in this thesis has been chosen from the many models previously used by other researchers, and its applicability to skin colour modelling has been justified. It is proven in this thesis that the Mahalanobis distance to the skin colour distribution is Gaussian in both the chromatic and normalised rg colour spaces. Most facial profile analysis techniques use either tangency or curvature to locate anthropometric features along the profile. Techniques based on both approaches have been implemented and compared. Neither approach is clearly superior to the other, but the results indicate that a hybrid technique, combining both approaches, could provide significant improvements. The areas of research most relevant to facial metrology are reviewed in this thesis and original contributions are made to the body of knowledge in each area. The techniques, results, literature reviews, and suggestions presented in this thesis provide a solid foundation for further research and hopefully bring the goal of automated facial metrology a little closer to being achieved.
7
ALMEIDA, LUCIANA ALVES DE. "METROLOGY: CITIZENSHIP INSTRUMENT." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4004@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORMetrologia: instrumento de cidadania configura um traçado crítico do estágio atual (1) da legislação brasileira vigente em metrologia e suas áreas correlatas e (2) do sistema educacional brasileiro em metrologia, ambas as temáticas entendidas como efetivos instrumentos orientados para o desenvolvimento da competitividade industrial e a consolidação da cidadania. O trabalho tem sua fundamentação no ideário filosófico contemporâneo, que volta a eleger o Homem e a qualidade de vida parâmetros e diferenciais competitivos nos processos de desenvolvimento lato sensu, quer econômico, quer social, político ou industrial. Na primeira vertente do trabalho, que trata da legislação em metrologia,determinou-se um corpus analítico que engloba (i) a Constituição Federal da República - a - Constituição cidadã -; (ii) o Código de Proteção e Defesa do Consumidor e (iii) o acervo da regulamentação técnica em metrologia, correlacionando-a com fatos marcantes da vida política e econômica do País. No que concerne a vertente da pesquisa que analisa a evolução do sistema educacional, são considerados aspectos críticos da pioneira experiência brasileira voltada à capacitação e à formação de profissionais em metrologia no País, em destaqu e: (i) programas e projetos de indução e consolidação da metrologia como instrumento assegurador da cidadania; (ii) o percurso evolutivo da educação formal em metrologia no contexto do sistema educacional brasileiro na conjuntura da consolidação da pósgraduação no País e (iii) de suas políticas industrial e de ciência e tecnologia.No contexto dessa ampla análise, focalizam-se os principais marcos de desenvolvimento industrial, impactos na competitividade e na construção da cidadania.Como conclusão, encaminham-se reflexões e proposições para a institucionalização das competências vigentes, para a congregação dos espaços congêneres e para o planejamento de metas de médio e longo prazo que assegurem o processo continuado de desenvolvimento da metrologia como agente desse processo global de transformação e de formação de cidadania.
Metrology: an instrument for citizenship aims at reviewing the present stage (1) of the Brazilian legislation on metrology and its correlated areas and (2) of the Brazilian education system in metrology, both matters understood as effective instruments that addresses the development of the industrial competitiveness and the consolidation of citizenship in the country. The work is based on contemporary philosophical concepts that have once more elected Man and the quality of life as a parameter and a competitive differential in the developmental processes as a whole, whether they are of economic, social, political or industrial nature. Regarding the legislative content of the work, the corpus of the analysis proposes to encompass (i) the Federal Constitution of the Republic - the - Citizen Constitution -; (ii)the Consumer, Protection and Defense Code; (iii) the body of technical Metrology regulations, inter-correlating this specific legislation with remarkable political and economic al facts of the Brazilian History. With respect to the evolution of the Brazilian education system, critical aspects of the pioneer Brazilian experience devoted to the development of human resources in metrology and metrology-related areas are considered. The analysis also focus on (i)programs and projects for the induction and consolidation of metrology as an instrument that ensures citizenship; (ii) the course along which formal education in metrology has evolved in the context of the Brazilian educational system in view of the consolidation of the postgraduate courses in the Country and (iii) of its industrial and science and technology policies. Within this broad analysis, the major landmarks of industrial development and their impact on industrial competitiveness and on the construction of citizenship have been focused. In the conclusion, a few reflections have been put forward along with proposals to institutionalize the powers and responsibilities that are currently in force, to congregate correlated spaces, and to plan medium and long-term goals for the purpose of ensuring a continuous process for the development of metrology as an agent of this ongoing process of global change.
8
Knott, Paul Alexander. "Robust quantum metrology." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/8931/.
Full textAbstract:
In optical interferometry path-entangled states such as NOON states have shown to give quantum-enhanced precision measurements, but these states are notoriously fragile to particle losses, which typically collapse the quantum state and destroy the phase information. A class of inherently robust states that show the potential for great improvements over the alternatives are the entangled coherent states (ECSs). We show that these states allow substantial improvements over unentangled `classical' states and highly-entangled NOON states for a wide range of loss values. We then describe a measurement scheme that can be used to measure these states with a precision close to the theoretical bound given by the quantum Fisher information. We then look at the quantum mechanisms that lead to precise measurements. In optical interferometry multi-mode entanglement is often assumed to be the driving force behind quantum enhanced measurements. Recent work has shown this assumption to be false, and here we show that when photon losses occur multi-mode entanglement is actually detrimental to obtaining quantum enhanced measurements. We specifically apply this idea to a superposition of coherent states, demonstrating that these states show a robustness to loss that allows them to significantly outperform their competitors in realistic systems. A practically viable measurement scheme is then presented that allows measurements close to the theoretical bound, even with loss. In this thesis we also consider superpositions of spin coherent states and their application to quantum metrology. Compared to optical states, spin systems have a distinctly different process of decoherence known as non-Markovian dephasing, which has shown to give greatly improved robustness to loss. We see that spin cat states give an enhanced scaling over the shot noise limit, even with dephasing, whilst being realisable with current technology.
9
Mehboudi, Mohammad. "Quantum metrology and thermometry in open systems." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/405328.
Full textAbstract:
En mi tesis exploro la metrología cuántica en sistemas abiertos, con especial enfoque en la estimaci
ón de temperatura cuántica o termometría. Para este objetivo, voy a clasificar mi estudio
en dos regímenes diferentes de equilibrio térmico y más allá del equilibrio térmico. En ambos
casos, mis colaboradores y yo planteamos cuestiones de interés fundamental y tecnológico.
Entre estas preguntas, señalo lo siguiente: ¿Cuáles son los límites de precisión máximos en
la termometría con sondas individuales? ¿Es posible mejorar estos límites utilizando recursos
cuánticos tales como las correlaciones cuánticas y la criticalidad cuántica?
No sólo encontramos la máxima precisión ligada a la termometría, planteada por las leyes físicas
de la naturaleza, sino también muestramos cómo explotar los recursos cuánticos para superar
los límites clásicos en la precisión, incluso a temperatura finita. Además, identificamos medidas
experimentalmente viables que pueden alcanzar estos límites. Específicamente, nuestros resultados
muestran que en una muestra de muchos cuerpos, las correlaciones cuánticas colectivas
pueden convertirse en observables óptimos para estimar con precisión la temperatura. A su vez,
las correlaciones de spin colectivo se pueden observar con espectroscopia cuántica de Faraday
no destructiva. Por lo tanto, nuestro método ofrece la posibilidad de inferir la máxima informaci
ón sobre la temperatura, dejando la muestra sin perturbar.
Fuera del equilibrio térmico, abordamos sistemas estáticos y dinámicos. En el primer caso,
encontramos limitaciones/oportunidades para la estimación a baja temperatura, y bajo gradiente
de temperatura en una muestra. Particularmente, identificamos que la precisión termom
étrica a baja temperatura puede ser significativamente mejorada mediante el fortalecimiento
del acoplamiento sonda-muestra. Nuestras observaciones pueden encontrar aplicaciones
prácticas en termometría a nanoescala y baja temperatura—un régimen que es particularmente
relevante para tecnologías cuánticas.
Con un punto de vista más aplicado, tales protocolos de no equilibrio dan lugar a bombas de
calor cuánticas autónomas. Por lo tanto, también pensamos en explorar la calidad de tales bombas
de calor con las sondas más pequeñas, es decir, un solo spin. Aunque a primera vista un
spin parece ser una sonda muy pequeña, confirmamos su eficiencia explorando bombas de calor
cuánticas. Nuestras técnicas pueden encontrar aplicaciones en el campo emergente de la ingenier
ía térmica cuántica, ya que facilitan el diagnóstico y la optimización del diseño de ciclos
termodinámicos complejos.
Cuando se trata de sistemas dinámicos, hemos formulado una teoría (fluctuación-disipación) con
la ayuda de la cual se puede identificar la mínima perturbación externa que afecta a un sistema
cuántico. Nuestra propuesta puede ser útil en la detección de la fuerzas cuánticas, como por
ejemplo, la detección interferométrica de ondas gravitatorias.In my thesis I explore quantum metrology in open systems, with a special focus on quantum temperature estimation, or thermometry. For this aim, I categorize my study in two different regimes of thermal equilibrium and beyond thermal equilibrium. In both cases, my collaborators and I, raise questions of fundamental and technological interest. Among such questions, I point out the followings: What are the ultimate precision bounds on thermometry with individual (single) probes? Is it possible to improve these bounds by using quantum resources such as quantum correlations and quantum criticality? We not only find the ultimate precision bound on thermometry, posed by physical laws of nature, but also show how to exploit quantum resources to surpass the classical bounds on precision, even at finite temperature. Furthermore, we identify experimentally feasible measurements which can achieve these bounds. Specifically, our results show that in a many-body sample, the collective quantum correlations can become optimal observables to accurately estimate the temperature. In turn, the collective spin correlations can be read out with the non-demolishing quantum Faraday spectroscopy. Hence, our method others inferring maximum information about the temperature, yet leaving the sample unperturbed. Out of thermal equilibrium, we address both static and dynamic systems. In the former case, we find the limitations/opportunities for estimation of low temperature, and small temperature gradient in a sample. Particularly, we identify that the thermometric precision at low temperature can be significantly enhanced by strengthening the probe-sample coupling. Our observations may find applications in practical nanoscale thermometry at low temperature—a regime which is particularly relevant to quantum technologies. With a more applied point of view, such non equilibrium protocols give rise to autonomous quantum heat pumps. Hence, we also give thought to probing the quality of such heat pumps with the tiniest probes, i.e., a single spin. Although at the first glance a spin seems to be a very small probe, we confirm its effciency in probing quantum heat pumps. Our techniques may find applications in the emerging field of quantum thermal engineering, as they facilitate the diagnosis and design optimization of complex thermodynamic cycles. When it comes to dynamic systems, we have formulate a (fluctuation-dissipation) theory with the help of which one can identify the smallest external perturbation which affects a quantum system. Our proposal might be found useful in quantum force detection, for instance, interferometric detection of gravitational waves.
10
Idowu, Ade. "Dynamic metrology of error motions in precision spindles using optical metrology." Thesis, Cranfield University, 1998. http://dspace.lib.cranfield.ac.uk/handle/1826/3688.
Full textAbstract:
Knowledge of the accuracies of air bearing spindles in the sub-micrometre to nanometre range is required for the design, commissioning and operation of ultra-precise machine tools, measurement systems and other machines employing high precision rotational motion. In order to verify the dynamic performance of a spindle, measurement is required of its error motions in the unwanted five degrees of freedom (one axial, two tilts and two radial motions). Presentation of these error motions (eg in the form of polar charts) can then be used to provide critical spindle metrology data including total, asynchronous and average error motion rosette profiles and their average and peak values. This thesis describes a metrology system based on optical interferometry for measuring such unwanted error motions in three degrees of freedom involving motion along the spindle axis (axial rectilinear displacement and tilts about orthogonal axes), incurred with rotation of a precision air spindle over its specified speed-range. The system is not sensitive to orthoaxial translations which may be measured using alternative methods. Possible alternative techniques for measuring any of the degrees of freedom include an array of proximity sensors, (one for each translational degree of freedom and a further one for each of the other rotational degrees of freedom), to measure the run-out of an artefact. Proximity sensors based upon capacitive or optical fibre back-scatter techniques each offer the required single degree-of-freedom non-contacting capability and bandwidth. In the current work, a Fizeau interferometer is used to monitor the motion of the spindle of a vertical axis ultra-precision facing machine using a test-artefact. This is a mirror with less than one fringe departure from planarity from which interferogram. fringe-patterns are captured, digitised and analysed synchronously as the spindle rotates. The issue of the prediction of the dynamic form and motions of the observed interferograrn arises and the earlier theory is extended to optimise the set-up, including provision of automatic servo- alignment of the optical axis with the axis of the spindle. Measurement interferograrn data is sampled at selected angular incremental positions of spindle-rotation and image processing techniques used to filter the fringe pattern, enabling measurement of spindle tilt and axial displacement. Issues of sampling with respect to the anticipated spatial angular frequency of the spindle run-out are considered with respect to the speed/frequency capability of data-acquisition and processing arrangements. Essentially, with a spindle rotating at typical machining speeds of 300- 3000 rev/min, for consistent error motions, the resolution of an error plot is principally a function of observational time. It is foreseen that the system will be applicable in research and production-support in ultra-precision machining production processes and in rotational metrology.
11
Bukulmez, Evren. "Technological Change And Metrology Services Medical Metrology And Its Effects On Society." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606121/index.pdf.
Full textAbstract:
Accuracy of measurements is one of the most vital issues for industry and society as a whole. In this context, medical devices create a significant impact on the costs of health care services, such as additional medicine treatments, longer hospital stays, etc. The main aim of this thesis is to analyze and explain the use of metrology services and the socio-economic impact of medical metrology on consumers in Turkey. A framework for economic impact assessment of the calibration services for three specific medical devices, namely patient bedside monitors, ventilators and pacemakers &ndashboth of which are required for use especially after open-heart surgeries, has been developed and a cost-benefit analysis has been performed. The Benefit-to-Cost ratios of the calibration activity on patient bedside monitors, ventilators and pacemakers were calculated as 36.74, 2.22 and 1.79, respectively. Calibration services seem to have a very favorable Benefit-to-Cost ratio even based on the lower-bound estimations.
12
Farner, William Robert. "On-chip probe metrology /." Online version of thesis, 2008. http://hdl.handle.net/1850/6207.
Full text
13
Rossouw, Daniel Johannes. "Probes in HF metrology." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5425.
Full textAbstract:
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Flanged coaxial probes are widely used to conduct accurate, broadband permittivity measurements of various dielectric materials. A metrology study, discussed in [1], revealed that small perturbations in measured permittivity data, are due to escaping common-mode (CM) current that propagates onto exposed VNA feed cabling. This is not considered in published permittivity extraction algorithms, like the National Institute of Standards and Technology (NIST) full-wave code that assumes an infinite flange radius. To characterise this effect we validate a finite volume time domain (FVTD) CST simulation model of an SMA coaxial probe, by probing sensitive E-fields in a metallic shielding cylinder, placed around it. For this process, electro-optic (EO) E-field sensors are considered and a Mach-Zehnder type sensor is designed. Manufacturing difficulties discontinues this approach, but the revisited extended centre conductor E-field probing technique proves successful. The technique entails a high dynamic range, two-port VNA measurement. Through CST we gain knowledge of the physics behind the CM-problem and the behaviour of fields around the coaxial probe. Different shielding environments are simulated to establish their ability to impede CM-current coupling onto measurement cabling. To study the CM-effect on extracted permittivity results, the investigation is extended to Short-Open-Load (SOL) calibrated face-plane measurements of dielectric solids. A CST model, which considers escaping CM-energy, is used to generate open circuit (OC) calibration coefficients and to serve as an independent extraction method. We inspect the effect of different shielding environments and through CST, extract accurate permittivity results for e00, to a degree not previously achieved for such systems. This allows comment on the infinite-flange-radius assumption of the NIST method and proves the significance of the CM-effect.
AFRIKAANSE OPSOMMING: Geflensde koaksiale probes word algemeen in die praktyk gebruik om akkurate, wyeband permitiwiteitmetings van diëlektriese materiale te verrig. ’n Studie wat in [1] bespreek word, dui aan dat klein verskynsels in gemete resultate, verband hou met gemene-modus (GM) stroom, wat ontsnap en teenwoording is aan die buitekant van onbeskermde voerkabels. Hierdie verkynsel word nie deur huidige volgolf ekstraksie-algoaritmes, soos die van NIST wat ’n onëindige flensradius aanvaar, in ag geneem nie. Om die GM-effek te karakteriseer, verifieer ons ’n eindige-volume tyd-gebied CST simulasiemodel, deur sensitiewe metings binne ’n silidriese metaalskerm, wat om so ’n probe geplaas word. Vir hierdie meting word elektro-optiese E-veld probes eers oorweeg. In gevolg word ’n Mach-Zehnder-tipe probe ontwerp, maar vervaardigingsprobleme en tyd-oorwegings kniehalter hierdie benadering. Heroorweging van die verlengde koaksiale sentraalgeleier, E-veld-probe tegniek, wat hoë dinamiese bereik twee-poort netwerkanaliseerder metings behels, slaag uiteindelik in hierdie doel. CST maak dit nou moontlik om die GM stroomprobleem te simuleer en spesefieke veldgedrag te kan waarneem. Verskillende afskermingsmetodes se vermoë om GM-koppeling na kabels te beperk word ondersoek. Die GM studie word uitgebrei na SOL-gekalibreerde, flensvlakverwysde permitwiteitmetings van diëlektriese vastestowwe. ’n CST model, wat GM stroom in ag neem, word gebruik om oopgeslote kalibrasiekofisiënte te genereer en dien ook as ‘n alternatiewe permitiwiteit ekstraksiemetode. Die effek van die verskillende afskermingstegnieke word ondersoek en deur die CST metode te gebruik, word ’n aansienlike verbetering in akkuraatheid van e00 waardes verkry. Dit regverdig kommentaar oor die aannames wat in die NIST metode gemaak word en beklemtoon die belangrikheid om GM stroom in ag te neem.
14
Szmuk, Ramon. "Atom chips for metrology." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066089/document.
Full textAbstract:
Cette thèse porte sur deux sujets principaux: l'évaluation de la stabilité d'une horloge sur microcircuit utilisant des atomes piégés (Trapped Atom Clock on a Chip - TACC) et l'extension de cette technologie vers la réalisation d'un interféromètre atomique sur la même puce. Cette combinaison constitue la base pour la réalisation de capteurs inertiels intégrés pour la navigation. Des travaux antérieurs ont installé l'horloge et ont découvert, entre autres, des temps de cohérence très longs, qui permettent une interrogation Ramsey jusqu'à 5 s, une condition préalable pour le fonctionnement à grande stabilité. Je présente ici la première évaluation approfondie de la stabilité de l'horloge. Avec mon prédécesseur, nous avons démontré les fluctuations de fréquences relatives de 5.8 10-13 à 1 s intégrant jusqu'à 6 10-15 à 30000 s.La deuxième partie de cette thèse vise à étendre la polyvalence de notre puce atomique pour créer un interféromètre. J'ai étudié divers régimes d'interféromètres en utilisant des potentiels habillés par microondes. Le premier régime consiste à déplacer l'un des états d'horloge verticalement pendant une séquence d'horloge Ramsey. Ceci permet la mesure de gradients de potentiel en exploitant la différence de fréquences entre les deux états. Le second régime utilise des champs microondes pour générer un potentiel de double puits dans l'un des états d'horloge et un seul puits dans l'autre.À partir du seul puits, un pulse-π sur la transition d'horloge constitue la séparatrice de l'interféromètre et conduit une séparation spatiale tout en préservant le même état interne pour les deux bras de l'interféromètreThis thesis covers two main subjects: the evaluation of the stability of a Trapped Atom Clock on a Chip (TACC) and the expansion of this technology towards creating an atom interferometer on the same chip. The combination of a clock and an interferometer on the same chip constitutes the basis for the realization of atom-based integrated inertial navigation units. Previous work installed the clock operation and discovered, among others, very long coherence times, which allow Ramsey interrogations of up to 5 s, a prerequisite for high stability operation. I present the first thorough evaluation of the clock stability. Together with my predecessor we have demonstrated relative frequency fluctuations of 5.8 10-13 at 1 s integrating down to 6 10-15 at 30,000 s. The second part of this thesis aims to expand the versatility of our atom chip to create an atom interferometer. I have studied various interferometer schemes using microwave dressed potentials and implemented these to the set-up. The first scheme, following work by P. Treutlein et al., involves displacing one of the clock states vertically during a Ramsey clock sequence thereby allowing the measurement of potential gradients by exploiting the differential frequency shift accumulated between the two states. Ramsey fringes where recorded for different durations of the splitting, resulting in a clear signal of the wavepacket separation. The second scheme uses microwave dressing to generate a double well potential in one of the clock states and a single well in the other. Starting in the single well, a π-pulse on the clock transition constitutes the beam splitter and leads to a spatial separation for the same internal state
15
Lyons, Ashley. "Two photon quantum metrology." Thesis, Heriot-Watt University, 2017. http://hdl.handle.net/10399/3272.
Full text
16
Berndtros, Ida, and Olivia Berggren. "Can metrology be value-based? : A case study of SKF's metrology service Mätcentrum." Thesis, Linnéuniversitetet, Ekonomihögskolan, ELNU, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19480.
Full textAbstract:
Metrology is a concept that is not known by many, it is the science of measurement. For such an unknown concept it has significant importance to both the manufacturing companies and the customers as they both need to be sure that the final products are correct and of high quality. Therefore many companies have a quality system within their company to measure and calibrate their instruments. To ensure that the measuring instruments used are correct they need to be calibrated towards national and international standards. If you cannot do that at the company the service needs to be purchased externally. SKF, Svenska Kullagerfabriken AB, has a metrology service that they use for their own manufacturing that they have sold externally before and want to start selling again. The purpose of this study was to investigate what the main value drivers are in the metrology market and based on those values create a service offer. To investigate the purpose a case study of SKF’s metrology service was made and interviews were performed on nine manufacturing companies within the western region of Sweden, with focus on Gothenburg. The theoretical framework is based on the market positioning strategy by Lovelock & Wirtz (2011). The market positioning strategy includes a market section, an internal section and a competitor section. These parts can be seen all through the thesis as it guided the authors through the process. The empirical findings show the interview answers, the value drivers and the competitor response profile. In the empirical chapter it was discovered that accreditation and accuracy are the two value drivers that the customers find most important in metrology. Those value drivers does both Mätcentrum and most of the competitors have. The empirical also show that the suppliers have a strong position in the market and can offer similar or more value than Mätcentrum. The conclusion is that it would be difficult for Mätcentrum to start selling their service externally again. This is due to the competition, mainly from existing competitors and suppliers in combination with the lack of differentiating elements in their offer. However there is still an opportunity for profitability if the communication of the values is adjusted after each customer’s need and received successfully.
17
Frazer, Robert Charles. "Measurement uncertainty in gear metrology." Thesis, University of Newcastle Upon Tyne, 2007. http://hdl.handle.net/10443/852.
Full textAbstract:
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.
18
Sawyer, Nicolas B. E. "Novel optical surface metrology methods." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287239.
Full text
19
Logan, Randy. "Optical metrology of thin films." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/46094.
Full text
20
Smith, Stuart T. "Mechanical systems in nanometre metrology." Thesis, University of Warwick, 1987. http://wrap.warwick.ac.uk/35981/.
Full textAbstract:
The work reported in this thesis was carried out in the School of Engineering Science, University of Warwick, between October 1984 and October 1987. Chapter 1 contains a review of recent developments in instrumentation that require both manipulation and measurement over the range 0.1-100nm. The instruments considered are the Scanning Tunnelling Microscope (STM), Stylus techniques, X-ray interferometry and x-ray microscopy. The rest of the thesis presents the design and assessment of a novel STM incorporating an X-ray interferometer, an ultra-high precision stylus measuring instrument and an x-ray microscope two axis specimen translation stage. Chapters 2 and 3 present an assessment of different mechanisms for the production of rectilinear motions having parasitic errors of better than mm. Theoretical and experimental investigations into monolithic parallel spring systems based on a notch type hinge and long range slideways based on a polymeric bearing sliding on a polished glass prism are presented. Optimisation of a soleniod magnet force transducer is presented as a drive technique for the former device, whilst a mechanically non-influencing feedscrew drive is described for the latter system. A stylus based measuring instrument, called "Nanosurf 2", that incorporates the polymeric slideway is presented in chapter 4. The performance of this system has been assessed and the results are presented in the following chapter. The linearity and accuracy of an electromagnetically driven, single crystal silicon, monolithic spring make it a suitable for use as the translation mechanism in a Scanning Tunnelling Microscope. Consequently, a three-axis spring has been constructed to generate the translations required for imaging. An X-ray interferometer is built into the probe axis to facilitate absolute calibration. This work is preceeded by an investigation into the generation of complex shapes in this brittle material. Finally, the current status of this work is reported with the presentation of initial experimental results.
21
DeMiglio, Andrew Scott. "FUNDAMENTAL METROLOGY OF EWRITER DISPLAYS." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1374653071.
Full text
22
Salter, Tara La Roche. "Metrology for ambient mass spectrometry." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28748/.
Full textAbstract:
Ambient mass spectrometry (AMS) is a new and versatile method for analysing a multitude of different sample types with the benefit of analysis at ambient pressure and the many other advantages that this entails. However, as these techniques are still in their infancy, metrological development of the techniques is essential. This is a critical step before AMS can be used reliably in the application areas in which it has shown great promise. The research in this thesis addresses the development of AMS sources, in particular plasma-assisted desorption-ionisation, PADI. Optimisation and characterisation is fundamental to understanding and developing the technique. Optimisation of PADI is addressed; this includes understanding the effects of different parameters to maximise signal intensities. The power, and temperature, of the plasma is shown to have a significant effect on the fragmentation observed in the mass spectra. This is an important result that is further explored with the use of thermal desorption to aid the analysis of low volatility molecules. The form of the analyte is also an important consideration for analysis by PADI; characteristic ions from powders are easily detected, whereas for thin film samples an analyte vapour pressure of greater than 10-4 Pa is needed. This result provides an indication of the limitations of PADI and what classes of analyte it will be successful at analysing. It is also shown that we can improve signal intensities using a heated sample stage allowing the analytes to be thermally desorbed before being ionised by the plasma. This is an important result for future work, where ambient plasma sources can be implemented as an ionisation source in conjunction with another mechanism, such as thermal or laser desorption, to generate gas-phase ions. A comparison of different ambient methods for personal care products shows the usefulness and also complementarities of PADI with desorption electrospray ionisation, DESI, one of the most established AMS techniques which utilises a different mechanism for desorption and ionisation. This also demonstrates the chemical information that can quickly be gained from these techniques, with minimal sample preparation. DESI is also compared to secondary ion mass spectrometry, SIMS. Vacuum-based techniques such as SIMS are much more established than ambient techniques; it is insightful to understand the advantages that each source can offer, for the analysis of different types of molecule as well as the mass spectral information that can be gained from SIMS and DESI.
23
Huang, Zixin. "Protocols for optical quantum metrology." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18067.
Full textAbstract:
This thesis explores various protocols which can be applied to quantum metrology, such that precision of the measurement can beat the best classical approaches. We first demonstrate that ancilla-assisted schemes can improve phase estimation in the presence of noise, and we propose an experiment to demonstrate these effects. Given that the use of ancillae helps, it is no surprise that there are noisy channels for which the optimal strategy may depend on the noise level. We show that there is a non-trivial crossover between the ancilla-assisted strategy and the parallel-entangled strategy for Pauli noise channels and the amplitude damping channel. We see that under certain circumstances, the environment cannot access the parameter of interest. We then integrated techniques from quantum communication, to derive a general framework that renders quantum metrology protocols into cryptographic ones. Here the protocol is unconditionally secure if the trusted parties wish only to achieve the standard quantum limit. If Heisenberg-limited precision is to be achieved, they sacrifice some security, where adversaries can access information, but only at the risk of getting caught at it (cheat-sensitivity). In many scenarios, the quantum Fisher information is achieved for only one value of the phase. In a particular phase estimation scheme that measures the parity at the output of a Mach-Zehnder interferometer where the input is a two-mode squeezed vacuum, this problem is particularly imminent. We apply an adaptive technique to resolve this issue, showing that one can achieve precisions substantially below the shot noise limit. The key to a quadratically enhanced improvement in quantum metrology is entanglement. Finally, we demonstrate in a photonic system how high-dimensional entanglement can be certified, and provide an alternate interpretation of entanglement from an information-theoretic perspective.
24
Congedo, Giuseppe. "Spacetime metrology with LISA Pathfinder." Doctoral thesis, Università degli studi di Trento, 2012. https://hdl.handle.net/11572/368702.
Full textAbstract:
LISA is the proposed ESA-NASA space-based gravitational wave detector in the 0.1 mHz - 0.1 Hz band. LISA Pathfinder is the down-scaled version of a single LISA arm. In this thesis it is shown that the arm -- named Doppler link -- can be treated as a differential accelerometer, measuring the relative acceleration between test masses. LISA Pathfinder -- the in-flight test of the LISA instrumentation -- is currently in the final implementation and planned to be launched in 2014. It will set stringent constraints, with unprecedented pureness, on the ability to put test masses in geodesic motion to within the required differential acceleration of 3\times10^{-14} m s^{-2} Hz^{-1/2} and track their relative motion to within the required differential displacement measurement noise of 9\times10^{-12} m Hz^{-1/2}, at frequencies relevant for the detection of gravitational waves. Given the scientific objectives, it will carry out -- for the first time with such high accuracy required for gravitational wave detection -- the science of spacetime metrology, in which the Doppler link between two free-falling test masses measures the spacetime curvature. This thesis contains a novel approach to the calculation of the Doppler response to gravitational waves. It shows that the parallel transport of 4-vectors records the history of gravitational wave signals passing through photons exchanged between an emitter and a receiver. In practice, the Doppler link is implemented with 4 bodies (two test masses and two spacecrafts) in LISA and 3 bodies (two test masses within a spacecraft) in LISA Pathfinder. Different non-idealities may originate in the measurement process and noise sources couple the motion of the test masses with that of the spacecraft. To compensate for such disturbances and stabilize the system a control logic is implemented during the measurement. The complex closed-loop dynamics of LISA Pathfinder can be condensed into operators acting on the physical coordinates describing the relative motion. The formalism can handle the couplings between the test masses and the spacecraft, the sensing noise, as well as the cross-talk, and allows for the system calibration. It suppresses the transients in the estimated residual acceleration noise between the test masses. The scope of system identification is indeed the calibration of the instrument and the compensation of different effects. After introducing a model for LISA Pathfinder along the optical axis and an example of cross-talk from other degrees of freedom to the optical axis, this thesis describes some data analysis procedures applied to synthetic experiments and tested on a realistic simulator provided by ESA. The same procedures will also be adopted during the mission. Those identification experiments can also be optimized to get an improvement in precision of the noise parameters that the performances of the mission depend on. This thesis demonstrates the fundamental relevance of system identification for the success of LISA Pathfinder in demonstrating the principles of spacetime metrology needed for all future space-based missions.
25
Congedo, Giuseppe. "Spacetime metrology with LISA Pathfinder." Doctoral thesis, University of Trento, 2012. http://eprints-phd.biblio.unitn.it/708/1/thesis_GCongedo.pdf.
Full textAbstract:
LISA is the proposed ESA-NASA space-based gravitational wave detector in the 0.1 mHz - 0.1 Hz band. LISA Pathfinder is the down-scaled version of a single LISA arm. In this thesis it is shown that the arm -- named Doppler link -- can be treated as a differential accelerometer, measuring the relative acceleration between test masses. LISA Pathfinder -- the in-flight test of the LISA instrumentation -- is currently in the final implementation and planned to be launched in 2014. It will set stringent constraints, with unprecedented pureness, on the ability to put test masses in geodesic motion to within the required differential acceleration of 3\times10^{-14} m s^{-2} Hz^{-1/2} and track their relative motion to within the required differential displacement measurement noise of 9\times10^{-12} m Hz^{-1/2}, at frequencies relevant for the detection of gravitational waves. Given the scientific objectives, it will carry out -- for the first time with such high accuracy required for gravitational wave detection -- the science of spacetime metrology, in which the Doppler link between two free-falling test masses measures the spacetime curvature. This thesis contains a novel approach to the calculation of the Doppler response to gravitational waves. It shows that the parallel transport of 4-vectors records the history of gravitational wave signals passing through photons exchanged between an emitter and a receiver. In practice, the Doppler link is implemented with 4 bodies (two test masses and two spacecrafts) in LISA and 3 bodies (two test masses within a spacecraft) in LISA Pathfinder. Different non-idealities may originate in the measurement process and noise sources couple the motion of the test masses with that of the spacecraft. To compensate for such disturbances and stabilize the system a control logic is implemented during the measurement. The complex closed-loop dynamics of LISA Pathfinder can be condensed into operators acting on the physical coordinates describing the relative motion. The formalism can handle the couplings between the test masses and the spacecraft, the sensing noise, as well as the cross-talk, and allows for the system calibration. It suppresses the transients in the estimated residual acceleration noise between the test masses. The scope of system identification is indeed the calibration of the instrument and the compensation of different effects. After introducing a model for LISA Pathfinder along the optical axis and an example of cross-talk from other degrees of freedom to the optical axis, this thesis describes some data analysis procedures applied to synthetic experiments and tested on a realistic simulator provided by ESA. The same procedures will also be adopted during the mission. Those identification experiments can also be optimized to get an improvement in precision of the noise parameters that the performances of the mission depend on. This thesis demonstrates the fundamental relevance of system identification for the success of LISA Pathfinder in demonstrating the principles of spacetime metrology needed for all future space-based missions.
26
Nichols, James Franklin. "Metrology of High Aspect Ratio MEMS." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5187.
Full textAbstract:
The current tools for geometric analysis of micro-electromechanical systems (MEMS) are primarily limited to those of the semiconductor industry. These tools are suited for measuring entities that are two-dimensional in nature such as lines, circles, and planes. Hardware that is capable of collecting three-dimensional data is typically limited by the slope variations in the surfaces of the part, and cannot accurately capture information from steep sidewalls, particularly in parts fabricated using the LIGA micro-fabrication process.
This research develops a methodology to qualify MEMS, by implementing a novel computer-aided inspection (CAI) software framework. This software platform uses data acquired from current MEMS inspection hardware, and applies newly developed analysis algorithms to geometrically characterize a part. This work implements algorithms for all the procedures typical to a CAI program (e.g., point-to-entity assignment, registration, and data analysis) in addition to new techniques suited for inspection of high aspect ratio MEMS. This methodology describes possible registration errors based on the type of geometries being analyzed and the type of data acquired. Analyses of multiple point clouds with the use of fiducial information are shown to provide a critical link between single point cloud analyses that has heretofore been unrealized.
27
Wolf, Peter. "Relativity and the metrology of time." Thesis, Queen Mary, University of London, 1997. http://qmro.qmul.ac.uk/xmlui/handle/123456789/1870.
Full textAbstract:
The motivation for this work is two-fold: the application of general relativity to the metrology of time on one hand (part II), and the use of the methods and technology of time metrology for tests of relativity on the other (part I). In Part I detailed theory for the treatment of the metrology of time in a relativistic context is developed. It provides mathematical expressions for application to the syntonisation and synchronisation of clocks and the realisation of the time coordinates of space-time reference systems. The theoretical expressions are developed to accuracies exceeding those of previous publications in order to accommodate any development in clock and time-transfer technology that can be expected in the near f uture. Part III presents two original experiments which test the theory of special relativity using state-of-the-art time metrology. The first experiment uses data from clock comparisons betweeng round clocks and clocks on board the Global Positioning System( GPS) satellites to test the second postulate of special relativity (the universality of the speed of fight). The experiment is sensitive to a possible anisotropy of the one-way speed of flight in any spatial direction, and on a non-laboratory scale (baselines; -> 20000 Ian) and provides the most stringent limits for the anisotropy published up to date. The second is a proposal for a test of special relativity using a spacecraft that carries an onboard atomic clock and uses a two way time transfer system. The potential accuracy of such a test is evaluated for the ESA/RSA ExTRAS (Experiment on Timing Ranging and Atmospheric Sounding)experiment which was planned for launch in 1997 but is now "on hold".
28
Maung, Tinaung Daniel. "Statistical metrology of interlevel dieletric thickness." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37776.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (leaves 60-62).
by Tinaung Daniel Maung.
M.Eng.
29
Ortiz, Julio Enrique. "New millennium interferometer laser metrology testbed." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42639.
Full text
30
Hines, Braden E. (Braden Eric). "Laser metrology system for stellar interferometry." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14769.
Full text
31
Cashmore, Matthew Thomas Dolphin. "Interferometric metrology using reprogrammable binary holograms." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7769/.
Full textAbstract:
Interferometric methods for surface metrology have been widely used for many years due to their speed, accuracy and versatility. It is frequently necessary however to produce a known comparison reference surface to minimise the optical path difference and hence enhance the dynamic range. An alternative to this is to use a computer generated hologram to act as the reference wave, or to correct a spherical reference wave to match a highly aspheric optic in order to achieve a null test. This thesis shall present a novel method of producing such holograms through the use of a binary ferroelectric liquid crystal on silicon spatial light modulator (FLCOS SLM) rather than using the more common lithographically produced plates. One of the primary advantages this could introduce is the ability for arbitrarily reprogrammable holograms to be created upon demand rather than needing to produce a series of holographic plates, saving both time and money in the testing of surfaces. We present results characterising the ability of a FLCOS SLM to produce increasingly large Zernike aberrations as well as quantifying the resulting errors, before using the device to reduce interferometric fringe density allowing us to measure aberrated optics and reveal low amplitude surface variations on the scale of 0.045 waves RMS.
32
Matthysen, Nardus. "Time domain metrology for MeerKAT systems." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95963.
Full textAbstract:
Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: This work in this study covers a powerful technique to derive propagation and scattering information in an expedient fashion. Expedient because time-domain (TD) data gathers a broad spectrum in a single transmitted pulse. TD has been criticised because of a lack of dynamic range, which has now been overcome by the direct sampling system, RATTY and RTA. This study focuses on the investigation of a TD metrology system, to assist with the characterisation of MeerKAT systems. The elementary components of the system include a fast-rising impulse generator that was coupled with an impulse radiating antenna (IRA). The system was calibrated and tested before practical measurements and preliminary testing in the Karoo were done. For TDmetrology a larger bandwidth accelerates measurements without the loss of accuracy. The pulse generator’s (PG’s) fundamental components are an avalanche transistor and a step recovery diode (SRD), to sharpen the leading edge of the pulse. Improving the rise-time of a pulse increases its bandwidth in the spectrum. The external circuitry around these components is pivotal and it determines the shape, amplitude and rise-time of the pulse. In the course of the investigation, the general circuitry around the PG was improved to obtain the best possible pulse for measurements inside a reverberation chamber (RC) and for measurements in the Karoo. In light of this, a second and third PG source were obtained. For measurements in the Karoo, a larger amplitude pulse was required to increase the spectral content and this is essential for propagation measurements over distance and the shielding effectiveness (SE) of structures. Stacking avalanche transistors allow larger amplitude pulses and it improves the dynamic range of the spectrum. A PG incorporating stacked avalanche transistors, was designed, built and measured to assist with RC and small-scale field measurements in the Karoo. The third PG was bought for the practical measurements in the Karoo. The PG produces kilovolt pulses with pico-second rise-times that extend the spectral range of the current PGs at our disposal. With these PGs, an antenna is required for the radiation of impulse-like transients. The IRA is a high-gain large-bandwidth antenna. The IRA consists of a parabolic reflector, conical-plate transmission lines that are terminated through resistors onto the dish, and a feeding balun. The IRA design was thoroughly discussed and a first model for metrology was designed, measured and optimised. The IRA was also simulated with computation software code, FEKO. Before deployment of theTDsystem, calibration and characterisation measurements are required. The measuring devices used within this study were sampling oscilloscopes and direct sampling systems. The limitations of each device were explored and are discussed. The final measurements that were conducted contribute to work related to the SKA. This incorporated antenna pattern calibration, propagation over distance and the SE of a berm built from Karoo soil. The system investigated the propagation attenuation over the Karoo soil and vegetation, with great promise. A broad spectrum was measured over a few kilometres and compared to free-space loss. The SE of the berm covered the same spectral bandwidth. In this measurement, scattering effects and knife-edge diffraction were observed.
AFRIKAANSE OPSOMMING: Die werk in hierdie studie dek ’n kragtige tegniek wat gebruik kan word om die voortplanting en die verstrooiingsinligting van elektromagnetiese golwe op ’n voordelige manier af te lei. Dit is voordelig, want tydgebieddata versamel ’n wye spektrum in ’n enkele oordraagbare puls. Tydgebied is in die verlede baie gekritiseer omdat dit ’n dinamiese reikwydte kortkom en dit is nou oorwin deur die direkte steekproefnemingstelsel, RATTY en RTA. Hierdie studie fokus op die ondersoek van ’n tydgebiedmetingssisteem en dit help met die karakterisering van MeerKAT sisteme. Die elementêre komponente van die sisteem bestaan uit ’n vinnig-stygende impulsgenerator wat gekoppel is aan ’n impulsuitstralende-antenna (IRA). Die sisteem is gekalibreer en getoets voordat praktiese metings en toetse in die Karoo uitgevoer kon word. Vir tydgebiedmetings versnel ’n groter bandwydte die metings sonder om die akkuraatheid daarvan te beïnvloed. Die pulsgenerator se fundamentele komponente is ’n stortvloedtransistor en ’n stap-herstel diode (SRD) wat die voorpunt van die puls verskerp. Die eskterne stroombaan rondom hierdie komponente is noodsaaklik en dit bepaal die vorm, amplitude en die stygtyd van die puls. Deur die loop van hierdie ondersoek is die algemene stroombaan rondom die puls verbeter, om die beste moontlike puls vir metings binne in die weerkaatsingskamer en vir metings in die Karoo, te verkry. Na aanleiding van dit is ’n tweede en derde pulsgenerator bron verkry. Vir die metings in die Karoo is ’n puls met ’n groter amplitude vereis om die spektrale inhoud te vermeerder. Dit is noodsaaklik vir elektromagnetiese golf voortplantingsmetings oor afstand asook die beskermings effektiwiteit (SE) van die strukture. Stapel-stortvloed transistors skep pulse met groter amplitudes en dit verbeter die dinamiese reikwydte van die spektrum. ’n Pulsgenerator wat gestapelde stortvloedtransistors insluit is ontwerp, gebou en gemeet om te help met metings in die weerkaatsingskamer en kleinskaal veldmetings in die Karoo. Die derde pulsgenerator is gekoop vir praktiese metings in die Karoo. Die pulsgenerator vervaardig kilovolt pulse met pikosekond stygtye, wat die reikwydte van die spektrum van ons huidige puls uitbrei. Hierdie pulsgenerators vereis ’n antenna vir die uistraling van impulsagtige seine. Die IRA is ’n hoë-wins, groot-bandwydte antenna. Die IRA bestaan uit ’n paraboliese weerkaatser, konieseplaat transmissielyne wat deur weerstande op die skottel getermineer word, asook ’n voedings "balun". Die IRA ontwerp is deeglik bespreek en ’n model is ontwerp, gemeet en verbeter. Die IRA is ook gesimuleer met behulp van ’n rekenaarsagtewareprogram, FEKO. Voordat die tydgebiedsisteem benut kan word, moet dit gekalibreer word en karakteriseringsmetings moet ook daarmee uitgevoer word. Die meetinstrumente wat in hierdie studie gebruik is, is steekproefneming-ossilloskope en direkte steekproefneming-sisteme. Die tekortkominge van elke instrument is ondersoek en bespreek. Die finale meting wat uitgevoer is, dra by tot die werk wat geassosieer word met die SKA. Dit behels antennapatroonkalibrasie, voortplanting van elektromagnetiese golwe oor afstand en die SE van ’n "berm"wat gebou is uit Karoo-grond. Hierdie sisteem is gebruik om die voortplantings-verswakking oor die Karoo-grond en plantegroei te ondersoek en dit lyk baie belowend. ’nWye spektrumis oor ’n paar kilometer gemeet en dit is met wrywinglose ruimte vergelyk. Die SE van die "berm"het dieselfde spektrale bandwydte gedek. In hierdie meting is verstrooiingseffekte en mespunt-diffraksie waargeneem.
33
Tsatourian, Veronika. "Femtosecond combs for optical frequency metrology." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2747.
Full textAbstract:
This thesis is dedicated to femtosecond combs as a tool for optical frequency metrology and as an integral part of an optical clock. After an overview of optical frequency measurement techniques, the design of two frequency combs based on mode-locked femtosecond lasers as they were at the beginning of my project is described. The first comb is based on an Er:fibre laser operating at a central wavelength of 1550 nm with a repetition rate of 100 MHz. The second is a Ti:sapphire-laser-based comb operating at a central wavelength of 810 nm with a repetition rate of 87 MHz. Improvements to the original design of the Ti:sapphire comb are detailed in the next chapter. A novel f-to-2f self-referencing scheme based on a pair of Wollaston prisms and employing a PPKTP crystal for SHG results in up to 20 dB enhancement of the signal to noise ratio in the carrier-envelope offset frequency beat signal f0 and in up to 15 dB lower phase noise in the f0 beat signal compared to a Michelson interferometer based system. Next, the factors influencing the stability and accuracy of the microwave reference signal and the performance of two synthesisers used for the stabilisation of the frequency combs were investigated. It is shown that stability of the maser reference signal is reduced by the distribution system by factor of 1.5. A fractional frequency change of 4.1(0.7) × 10−16 (K/h)−1 was measured for the better of the two synthesisers (an IFR 2023A) indicating that for accurate frequency measurements the synthesiser signal should be monitored to enable systematic frequency corrections to be made. Finally, an absolute frequency measurement of the electric quadrupole clock transition in a frequency standard based on a single 171Yb+ trapped ion is described. The result f = 688 358 979 309 310 ± 9 Hz agrees with an independent measurement made by the PTB group within the uncertainty of the measurements.
34
Dietlein, Charles Robert. "Components and metrology for terahertz imaging." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3315848.
Full text
35
Cooper, Jessica Jane. "Quantum metrology with Bose-Einstein condensates." Thesis, University of Leeds, 2011. http://etheses.whiterose.ac.uk/1690/.
Full textAbstract:
The ability to make ultra-precise measurements is fundamentally important to science as it allows theories to be tested and refined. Interferometers offer unrivalled measurement precision and therefore form the basis of many metrology schemes. Research has shown that by using quantum states as inputs to interferometers, precisions better than anything possible classically can be achieved. Nevertheless, these states are difficult to produce and fragile to particle losses. Consequently, classical inputs, which are extremely robust, are used in experiments. Here, however, we propose experimentally accessible schemes to make quantum-limited measurements, in particular rotation measurements using Bose-Einstein condensates, that are robust to losses. We begin by describing how, by loading a Bose-Einstein condensate into an optical ring lattice, multiport beam splitters are created through a simple raising and lowering of potential barriers between sites. We then use these ‘splitters’ to create an atomic gyroscope. We demonstrate how to create several quantum states in the gyroscope, all capable of making rotation measurements. Whilst NOON states afford best precision in idealised set-ups, we find they are outperformed by ‘bat’ states for modest loss rates. However, bat states are not ideal as they are outperformed by classical states for large losses. A second gyroscope scheme is therefore developed. Using multiple momentum modes, rather than just two, we show quantum-limited precisions can be reached using states that have similar robustness to classical states. The final section focuses on the precision of linear interferometers. Recent work[1, 2] has calculated the theoretical optimum initial states for two-mode lossy interferometers. Here we present an experimental way to produce initial states that afford similar precisions to this optimum. We also consider lossy multimode interferometry and demonstrate a potential advantage over two-mode systems. It is thought with further investigation other advantages will be found.
36
Seong, Kibyung. "Optical Metrology for Transmission Interferometric Testing." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194698.
Full textAbstract:
The degree of sophistication and customization available in optical components has been driven by advances in lens design and fabrication. The optical testing of these components remains a challenge. In particular, the precision measurement of the properties of transmissive optics such as transmitted wavefront, surface figure, and index of refraction continues to require new methodology tools.A method of surface figure measurement is described based on the transmitted wavefront of an optical element obtained from a Mach-Zehnder interferometer. Given known values for the refractive index and center thickness, along with the sample's transmitted wavefront, the unknown surface profile is reconstructed in a deterministic way. The technique relies on knowledge of one of the surfaces of the element, such as an easy to measure plano or spherical surface, and is well-suited for testing aspheric surfaces. Additionally, this method has the advantage of making measurements on multiplexed surfaces, such as a lenslet array.Since the index of refraction of materials varies with wavelength, the test sample undergoes chromatic effects with wavelength. Chromatic aberration is an important concern whenever optics are designed for use in the visible spectrum. A method has been presented for obtaining the longitudinal chromatic aberration of a test part from the transmitted wavefronts at 5 different wavelengths. The longitudinal chromatic aberration measurements on a plano-convex lens and an achromat are presented.Injection molding is becoming a popular manufacturing method for optical plastic elements because of low cost and mass production. During injection molding, the plastic lenses undergo large pressure and temperature changes so that the resulting lens has a spatially-varying index. Since the index is assumed to be a single number in the design stage, except for index-gradient lenses, an inhomogeneous index of the sample can cause a decrease in optical performance. The surface reconstruction algorithm can be modified to find two dimensional index values over the test aperture. In this case, both surfaces are measured by an external interferometer and one unknown parameter is the index value.
37
TRAN, NGOC THANH MAI. "Novel techniques for electrical impedance metrology." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2910078.
Full text
38
Shettell, Nathan. "Quantum Information Techniques for Quantum Metrology." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS504.
Full textAbstract:
La métrologie quantique est une discipline prometteuse de l'information quantique qui connaît actuellement une vague de percées expérimentales et de développements théoriques. L'objectif principal de la métrologie quantique est d'estimer des paramètres inconnus aussi précisément que possible. En utilisant des ressources quantiques comme sondes, il est possible d'atteindre une précision de mesure qui serait autrement impossible en utilisant les meilleures stratégies classiques. Par exemple, en ce qui concerne la tâche d'estimation de la phase, la précision maximale (la limite d'Heisenberg) est un gain de précision quadratique par rapport aux meilleures stratégies classiques. Bien entendu, la métrologie quantique n'est pas la seule technologie quantique qui connaît actuellement des avancées. Le thème de cette thèse est l'exploration de la manière dont la métrologie quantique peut être améliorée par d'autres techniques quantiques lorsque cela est approprié, à savoir : les états graphiques, la correction d'erreurs et la cryptographie. Les états de graphes sont une ressource incroyablement utile et polyvalente dans l'information quantique. Nous aidons à déterminer l'étendue de l'applicabilité des états de graphes en quantifiant leur utilité pour la tâche de métrologie quantique de l'estimation de phase. En particulier, l'utilité d'un état de graphe peut être caractérisée en fonction de la forme du graphe correspondant. À partir de là, nous concevons une méthode pour transformer tout état de graphe en un état de graphe plus grand (appelé "bundled graph states") qui sature approximativement la limite de Heisenberg. En outre, nous montrons que les états de graphe constituent une ressource robuste contre les effets du bruit (le déphasage et un petit nombre d'effacements) et que la limite quantique de Cramér-Rao peut être saturée par une simple stratégie de mesure. Le bruit issu de l’environnement est l'un des principaux obstacles à la métrologie quantique, qui limite la précision et la sensibilité qu'elle peut atteindre. Il a été démontré que si le bruit environnemental peut être distingué de la dynamique de la tâche de métrologie quantique, des applications fréquentes de correction d'erreurs peuvent être utilisées pour combattre les effets du bruit. En pratique, cependant, la fréquence de correction d'erreurs requise pour maintenir une précision de type Heisenberg est impossible à atteindre pour les technologies quantiques actuelles. Nous explorons les limites de la métrologie quantique améliorée par la correction d'erreurs en prenant en compte les contraintes et les obstacles technologiques, à partir desquels nous établissons le régime dans lequel la limite d'Heisenberg peut être maintenue en présence de bruit. La mise en œuvre complète d'un problème de métrologie quantique est technologiquement exigeante : des états quantiques intriqués doivent être générés et mesurés avec une grande fidélité. Une solution, dans le cas où l'on ne dispose pas de tout le matériel quantique nécessaire, consiste à déléguer une tâche à un tiers. Ce faisant, plusieurs problèmes de sécurité se posent naturellement en raison de la possibilité d'interférence d'un adversaire malveillant. Nous abordons ces questions en développant la notion de cadre cryptographique pour la métrologie quantique. Nous montrons que la précision du problème de la métrologie quantique peut être directement liée à la solidité d'un protocole cryptographique employé. En outre, nous développons des protocoles cryptographiques pour une variété de paramètres motivés par la cryptographie, à savoir : la métrologie quantique sur un canal quantique non sécurisé et la métrologie quantique avec une tâche déléguée à une partie non fiable. Les réseaux de détection quantique ont suscité un intérêt croissant dans la communauté de la métrologie quantique au cours des dernières années. Ils constituent un choix naturel pour les problèmes distribués dans l'espace et les problèmes multiparamètres.[...]Quantum metrology is an auspicious discipline of quantum information which is currently witnessing a surge of experimental breakthroughs and theoretical developments. The main goal of quantum metrology is to estimate unknown parameters as accurately as possible. By using quantum resources as probes, it is possible to attain a measurement precision that would be otherwise impossible using the best classical strategies. For example, with respect to the task of phase estimation, the maximum precision (the Heisenberg limit) is a quadratic gain in precision with respect to the best classical strategies. Of course, quantum metrology is not the sole quantum technology currently undergoing advances. The theme of this thesis is exploring how quantum metrology can be enhanced with other quantum techniques when appropriate, namely: graph states, error correction and cryptography. Graph states are an incredibly useful and versatile resource in quantum information. We aid in determining the full extent of the applicability of graph states by quantifying their practicality for the quantum metrology task of phase estimation. In particular, the utility of a graph state can be characterised in terms of the shape of the corresponding graph. From this, we devise a method to transform any graph state into a larger graph state (named a bundled graph state) which approximately saturates the Heisenberg limit. Additionally, we show that graph states are a robust resource against the effects of noise, namely dephasing and a small number of erasures, and that the quantum Cramér-Rao bound can be saturated with a simple measurement strategy. Noise is one of the biggest obstacles for quantum metrology that limits its achievable precision and sensitivity. It has been showed that if the environmental noise is distinguishable from the dynamics of the quantum metrology task, then frequent applications of error correction can be used to combat the effects of noise. In practise however, the required frequency of error correction to maintain Heisenberg-like precision is unobtainable for current quantum technologies. We explore the limitations of error correction enhanced quantum metrology by taking into consideration technological constraints and impediments, from which, we establish the regime in which the Heisenberg limit can be maintained in the presence of noise. Fully implementing a quantum metrology problem is technologically demanding: entangled quantum states must be generated and measured with high fidelity. One solution, in the instance where one lacks all of the necessary quantum hardware, is to delegate a task to a third party. In doing so, several security issues naturally arise because of the possibility of interference of a malicious adversary. We address these issues by developing the notion of a cryptographic framework for quantum metrology. We show that the precision of the quantum metrology problem can be directly related to the soundness of an employed cryptographic protocol. Additionally, we develop cryptographic protocols for a variety of cryptographically motivated settings, namely: quantum metrology over an unsecured quantum channel and quantum metrology with a task delegated to an untrusted party. Quantum sensing networks have been gaining interest in the quantum metrology community over the past few years. They are a natural choice for spatially distributed problems and multiparameter problems. The three proposed techniques, graph states, error correction and cryptography, are a natural fit to be immersed in quantum sensing network. Graph states are an well-known candidate for the description of a quantum network, error correction can be used to mitigate the effects of a noisy quantum channel, and the cryptographic framework of quantum metrology can be used to add a sense of security. Combining these works formally is a future perspective
39
Teke, Onur Ahmet. "Investigation of Modularization of Measurement Programs for CMMs." Thesis, KTH, Industriell produktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118639.
Full textAbstract:
Coordinate measurement machines (CMMs) are used to control whether workpieces meet customers’ need or not. Creating measurement programs for CMMs takes long time and companies try to find a way to decrease the time for preparation processes. The aim of this thesis work is to investigate the measurement processes of products within Sandvik Coromant AB in Gimo, Sweden and to focus on the preparation of modularized measurement programs. The main goal is to study measurement processes in the company, and to find and recommend different alternatives for modularization of measurement programs of products so that time and energy can be saved. In order to understand the current measurement processes in the company with its gaps and risks and also to be able to find further possible improvements, many interviews, meetings and a questionnaire have been made. Employees’ opinions and ideas about modularization of measurement programs have been collected. Three different cases about modularization of measurement programs have been presented in the thesis work. The first case is about the actual situation in the company. The gaps and risks which have been observed and collected have been presented. The second case focuses on modularization of today’s insert seats into two pieces: insert seat module and pre-stress module. The third case focuses on the feasibility of dividing the insert seats into much smaller modules. In the conclusion part, all three cases and all work which has been done during the thesis are presented. Last but not least, some further research subjects are shown on the recommendation part.Koordinatmätmaskiner (CMMs) används för att kontrollera om produkterna möter kundernas behov eller inte. Att skapa mätprogram för CMMs tar lång tid och företagen försöker hitta sätt att minska tiden för förberedelseprocesser. Syftet med detta examensarbete är att undersöka mätprocesser av produkterna inom Sandvik Coromant AB i Gimo, Sverige och att fokusera på förberedelserna av modulariserade mätprogram. Det huvudsakliga målet var att studera mätprocessen i företaget, samt att ta reda på och rekommendera olika alternativ för modularisering av mätprogram för produkter för att på så sätt kunna spara tid och energi. För att förstå de aktuella mätprocesserna i företaget med brister och risker och även att kunna ta reda på ytterligare möjliga förbättringar, har många intervjuer, möten och ett frågeformulär gjorts. Medarbetarnas åsikter och idéer om modularisering av mätprogrammen har samlats in. Tre olika fall om modularisering av mätprogram presenteras i examensarbetet. Det första fallet handlar om den nuvarande situationen i företaget. De brister och risker som har observerats och samlats in presenteras. Det andra fallet fokuserar på modularisering av dagens skärläge in i två delar som skärlägesmodul och förspänningsmodul. Det tredje fallet fokuserar på möjligheten att dela upp skärlägen i mycket mindre moduler. I slutsatsen sammanfattas alla tre fallen och allt arbete som har gjorts varvid resultat och slutsatser presenteras. Sist men inte minst, visas på några ytterligare forskningsfrågor i rekommendationsdelen.
40
Atashkhooei, Reza. "Adaptive self-mixing interferometry for metrology applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/134357.
Full textAbstract:
Among the laser based techniques proposed for metrology applications, classical interferometers offer the highest precision measurements. However, the cost of some of the elements involved and the number of optical components used in the setup complicates using them in several industrial applications. Apart from cost, the complexities due to optical alignment and the required quality of the environmental conditions can be quite restrictive for those systems. Within the category of optical interferometers, optical feedback interferometry (OFI), also called self-mixing interferometry (SMI) has the potential to overcome some of the complexities of classical interferometry. It is compact in size, cost effective, robust, self-aligned, and it doesn't require a large number of optical components in the experimental configuration. In OFI, a portion of the emitted laser beam re-enters to the laser cavity after backreflection from the target, causing the wavelength of the laser to change, modifying the power spectrum and consequently the emitted output power, which can be detected for measurement purposes. Thus, the laser operates simultaneously as the light source, the light detector, and as the ultra-sensitive coherent sensor for optical path changes.
The present PhD pursued improving the performance of OFI-based sensors using a novel and compact optical system. A solution using an adaptive optical element in the form of a voltage programmable liquid lens was proposed for automated focus adjustments. The amount of backreflected light re-entering the laser cavity could be controlled, and the laser feedback level was adjusted to the best condition in different situations, enabling the power signal to be adjusted to the best possible conditions for measurement. Feedback control enabled the proposal of a novel solution called differential OFI, which improved the measurement resolution down to the nanometre order, even if the displacements were below half-wavelength of the laser, for first time in OFI sensors.
Another relevant part of the PhD was devoted to the analysis of speckle-affected optical power signals in feedback interferometers. Speckle effect appears when the displacements of the target are large, and introduces an undesired modulation of the amplitude of the signal. After an analysis of the speckle-affected signal and the main factors contributing to it, two novel solutions were proposed for the control of speckle noise. The adaptive optical head developed previously was used in a real time setup to control the presence of speckle effect, by tracking the signal to noise ratio of the emitted power, and modifying the spot size on the target when required using a feedback loop. Besides, a sensor diversity solution was proposed to enable enhancements in signal detection in fast targets, when real time control could not be applied.
Finally, two industrial applications of the technique with the presence of different levels of speckle noise have been presented. A complete measurement methodology for the control of motor shaft runout in permanent magnet electrical motors, enabling complete monitoring of the displacement of the shaft has been developed and implemented in practice. Results here are validated with those obtained using a commercial laser Doppler vibrometer, an equipment with a much higher cost. A second application in the monitoring the displacement of polymer-reinforced beams used in civil engineering under dynamic loading was also demonstrated. Results here are validated using a conventional contact probe (a Linear Vertical Differential Transducer, LVDT). Both applications show that with controlled speckle features OFI performs adequately in industrial environments as a non-contact proximity probe with resolution limited by the constraints defined by the setup
41
Lee, Woei Ming. "Optical trapping : optical interferometric metrology and nanophotonics." Thesis, St Andrews, 2010. http://hdl.handle.net/10023/882.
Full text
42
Johanssson, Stefan. "Precision Amplifier for Applications in Electrical Metrology." Thesis, Linköping University, Linköping University, Electronics System, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16896.
Full textAbstract:
This master's thesis addresses two main problems. The first is how to suppress a common mode voltage that appears for current shunts, and the second how to let a voltage divider work under an unloaded condition to prevent loading errors and thereby a decreased measurement accuracy. Both these problems occurs during calibration of power meters, and verification of current shunts and voltage dividers. To the first problem three alternative solutions are presented; prototype a proposed instrumentation amplifier circuit, evaluate the commercial available instrumentation amplifier Analog Devices AD8130 or let the voltage measuring device suppress the common mode voltage. It is up to the researchers at SP to choose a solution. To address the second problem, a prototype buffer amplifier is built and verified. Measurements of the buffer amplifier show that it performs very well. At 100 kHz, the amplitude error is less than 20 μV/V, the phase error is less than 20 μrad, and the input Rp is over 10 MΩ. This is performance in line with the required to make accurate measurements possible at 100 kHz and over that.
43
Sand, Åsmund. "Applying the Internet to Instrumentation and Metrology." Doctoral thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1236.
Full textAbstract:
The work describes useful approaches to applying the Internet in electrical metrology and calibration.
The work comprises several approaches to Internet-enabled metrology, including running remote measurements and remotely operating instruments. The author proposes new ways of developing Internetenabled instrumentation systems, focusing on increasing the availability while preserving the security.
44
Brujic, Djordje. "A framework for CAD based shape metrology." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271757.
Full text
45
Claus, David. "High accuracy metrology using low-resolution cameras." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442843.
Full text
46
Warden, Matthew Stuard. "Absolute distance metrology using frequency swept lasers." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:a20e9c69-e580-48d8-bbce-51d8f4186450.
Full textAbstract:
This thesis describes and evaluates two new interferometric distance measurement methods based upon the well known method of Frequency Scanning Interferometry (FSI). These new methods are known as Dynamic FSI and Cascaded FSI. Dynamic FSI addresses the two problems, commonly seen in previous FSI implementa- tions, of not being able to measure a moving target and having a slow measurement rate. This method measures stationary and moving targets equally well, and can determine the distance to the target at all times during the measurement, in contrast to previous methods, which obtain only a single measured length from a measurement process which can take up to a second to make. Cascaded FSI was developed with the aim of increasing the accuracy and precision of FSI. This method allows for measurements with precision equal to that of displacement interferometry, and also provides a way of measuring length relative to the frequencies of atomic absorption lines, which are inherently more stable length references than a physical length artefact.
47
Bledowski, Ian A. "Frequency-division-multiplexing technique for imaging metrology." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9286.
Full textAbstract:
An algorithm to multiplex multiple image captures simultaneously onto a single image sensor at full frame resolution was developed for imaging metrology. Parseval’s theorem was used to obtain the image intensity from image time-series of around typically 256 frames captured by the imaging sensor at typically 60 fps, though kHz frame rates are possible, hardware permitting. The time-series contained contributions from each image channel in the system, which were created by periodically modulating the intensity of the light source which defined that channel. The modulating time-series was converted to a frequency representation by Fourier transform and from that the channels could be identified by their peaks in the spectrum. Peaks corresponding to each channel were then isolated with a window function and Parseval’s theorem applied on a pixel by pixel basis to convert the signal strength back to an image containing the information from that channel only.
The FDM algorithm was then applied to two imaging metrology methods. First, an in-plane, two-channel shearography system was multiplexed with FDM in such a way as to allow time-division multiplexed measurements to be taken on the same deformations with the same instrument so as to allow comparison of results from other methods. FDM was found to produce good quality results comparable with current methods. Interferometric planar Doppler velocimetry was performed, multiplexing the reference phase channel signal and a signal channel for both a wheel and a gas jet. FDM was found to suppress the effects of phase drifts in the system which would lead to velocity offsets in the results, and gave velocities which varied from the model by only up to ~5%.
Finally, an error analysis was performed on the FDM algorithm, comparing the technique with time-averaging and single image capture through simulation and practical methods. It was shown that FDM strongly suppresses the noise and background in a measurement, and can produce good images from low intensity signals.
It could be concluded that the FDM algorithm offers significant advantages over time-averaging a signal when applied to a multi-channel imaging metrology system.
48
Shields, Brendan John. "Diamond platforms for nanoscale photonics and metrology." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11638.
Full textAbstract:
Observing and controlling solid state quantum systems is an area of intense research in quantum science today. Such systems offer the natural advantage of being bound into a solid device, eliminating the need for laser cooling and trapping of atoms in free space. These solid state "atoms" can interface directly with photonic channels designed to efficiently couple into larger networks of interacting quantum systems. With all of the tools of semiconductor fabrication technology available, the idea of scalable, chip-based quantum networks is a tantalizing prospect.Physics
49
Holmes, R. D. "Coherent optical detection techniques in surface metrology." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294698.
Full text
50
Samaan, Noel D. "Mathematical modelling of instruments for pressure metrology." Thesis, City University London, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256742.
Full text