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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Validation of Optical Coherence Tomography-Based Crystalline Lens Thickness Measurements in Children

Lehman, Bret M. 14 July 2009 (has links)
No description available.
62

Accuracy and Repeatability of a Robotic Arm / Noggrannhet och repeterbarhet för en Robotarm

Lidholm, Carl-Victor, Runnquist, Victor January 2021 (has links)
The purpose of this project was to create a model of a robotic arm with 4-DOF equipped with a gripper that is able to move an object to a predetermined area. This thesis investigated the robotic arm’s accuracy by repeating the same predetermined movement and measure the error. The error was measured based on the objects displacement from the target area after a series of repeated movements by the arm. After constructing the robotic arm, an experiment was set up to measure the accuracy and repeatability of the arm. The robot achieved 2.506 mm to 0.922 mm for accuracy and 5.995 mm to 4.059 mm for repeatability depending on speed. / Syftet med detta projekt var att skapa en modell av en robotarm med 4 frihetsgrader och en klo för att kunna flytta ett objekt till ett förbestämt område. Denna avhandling har undersökt robotens noggrannhet genom att upprepa enförbestämd rörelse och mäta felet. Felet bestämdes genomatt flytta ett objekt till en förbestämd plats och mäta objektets position i förhållande till målet. Den färdigkonstruerade roboten har en noggrannhet på 2.506 mm till 0.922 mm och en repeterbarhet på 5.995 mmtill 4.059 mm beroende på hur fort roboten rör sig.
63

Enhancing Network-Level Pavement Macrotexture Assessment

Bongioanni, Vincent Italo 30 April 2019 (has links)
Pavement macrotexture has been shown to influence a range of safety and comfort issues including wet weather friction, splash and spray, ambient and in-vehicle noise, tire wear, and rolling resistance. While devices and general guidance exist to measure macrotexture, the wide-scale collection and use of macrotexture is neither mandated nor is it typically employed in the United States. This work seeks to improve upon the methods used to calibrate, collect, pre-process, and distill macrotexture data into useful information that can be utilized by pavement managers. This is accomplished by 1. developing a methodology to evaluate and compare candidate data collection devices; 2. plans and procedures to evaluate the accuracy of high-speed network data collection devices with reference surfaces and measurements; 3. the development of a method to remove erroneous data from emerging 3-D macrotexture sensors; 4. development of a model to describe the change in macrotexture as a function of traffic; 5.finally, distillation of the final collected pavement surface profiles into parameters for the prediction of important pavement surface properties aforementioned. Various high-speed macrotexture measurement devices were shown to have good repeatability (between 0.06 to 0.09mm MPD) and interchangeability of single-spot laser dfevices was demonstrated via a limits of agreement analysis. The operational factors of speed and acceleration were shown to affect the resulting MPD of several devices and guidelines are given for vehicle speed and sensor exposure settings. Devices with single spot and line lasers were shown to reproduce reference waveforms on manufactured surfaces within predefined tolerances. A model was developed that predicts future macrotexture levels (as measured by RMS) for pavements prone to bleeding due to rich asphalt content. Finally, several previously published macrotexture parameters along with a suite of novel parameters were evaluated for their effectiveness in the prediction of wet weather friction and certain types of road noise. Many of the parameters evaluated outperformed the current metrics of MPD and RMS. / Doctor of Philosophy
64

Immersive Exploration Experiences: Using Multi-Branching Decision Narratives as a Design Framework for Advanced Audience Engagement

White, Arianna 01 January 2023 (has links) (PDF)
Although ‘immersive experiences' and ‘immersion' are popular keywords in the themed entertainment industry today, they lack clear definition and criteria in their design and application. Nevertheless, there has been an increase in guest demand for these types of experiences and for these spaces to develop innovative methods that increase the degree to which audiences are able to engage with them. This thesis iterates cohesive design criteria for immersive experiences as they continue their trend toward increased engagement, interactivity, and guest agency in physical manifestations of imaginary worlds. This trend is explored through contextual references from the industry and an assessment of their implementation of the criteria towards increasingly immersive spaces. However, the current trajectory of these experiences does not demonstrate holistic consideration of the various elements required to progress towards true “advanced immersion” for the future of themed design. A new design practice is put forward for practitioners: “Immersive Exploration Experiences.” This framework progresses towards advanced immersion by considering varied guest roles and offering personalized, branching narrative structures as a key tenet. The Immersive Exploration Experiences concept is further illustrated with example design implementations accompanied by exploration tree diagrams that show the combination of dynamic, interactive, and engaging elements. The intent of this thesis is to provide a template for creating next generation immersive experiences which are built upon dynamic guest roles, transformative spaces, repeatable narratives, and other advanced elements that give every guest an opportunity to create their own path through an imaginary world.
65

Avaliação da repetibilidade e da reprodutibilidade do ensaio de duplo puncionamento. / Evaluation of the repeatability and reproducibility of the double punch test.

Nogueira, André Baltazar 02 May 2019 (has links)
Os avanços na utilização do concreto reforçado com fibras (CRF) para fins estruturais trazem cada vez mais a necessidade de se desenvolver ensaios práticos que possam controlar o material, analisando a capacidade resistente residual do compósito para diferentes níveis de abertura de fissura. O ensaio de duplo puncionamento (EDP) é uma promissora alternativa nesta direção, uma vez que haja uma correlação já comprovada com outros métodos de ensaio bem estabelecidos. Este trabalho objetivou investigar a repetibilidade e reprodutibilidade do EDP, considerando os parâmetros de cargas de fissura da matriz cimentícia e cargas residuais, verificando se existe igualdade de médias e igualdade de variâncias nas diferentes situações criadas, para 95% de confiabilidade. A repetibilidade foi avaliada por meio de um programa experimental, com moldagem dos corpos de prova no Centro de Pesquisa e Desenvolvimento da Construção Civil - CPqDCC, da Escola Politécnica da Universidade de São Paulo, envolvendo dois teores de fibra de aço com ancoragem em gancho (30 kg/m³ e 55 kg/m³) em três séries iguais de moldagem. A reprodutibilidade foi avaliada em um programa interlaboratorial, com participação de 6 laboratórios independentes e empregando a mesma fibra e teores. Como ferramentas para comparação dos resultados e avaliar se houve repetição e reprodução dos parâmetros do ensaio, foi utilizada análise de variância (ANOVA) e a metodologia da ASTM E691. Os resultados mostraram que foi possível obter repetibilidade e reprodutibilidade de médias para os parâmetros de cargas residuais com um número limitado de corpos de prova. No entanto, as variâncias são mais sensíveis que as médias, e não mostraram repetição total quando a homogeneização das fibras no volume total do concreto é prejudicada. Ainda, as cargas de fissuração do ensaio (Pf) não se mostraram totalmente repetíveis e nem reprodutíveis, pois podem ser afetadas pela máquina de ensaio e operador. / The advances in the use of fiber reinforced concrete (CRF) for structural applications bring the need to develop more practical tests to control the FRC by analyzing the residual strength of the composite for different crack openings levels. The double punch test (DPT) is a promising alternative in that sense, once a correlation with already proven test methods is achievable. This work aimed to investigate the repeatability and reproducibility of the DPT, considering the parameters of crack load and residual loads, verifying if there is equality of means and equality of variances in the different situations created, for 95% reliability. The repeatability was evaluated by an experimental program, with the specimens molding at the Research and Development Center in Civil Construction - CPqDCC, at the Polytechnic School of the University of São Paulo, involving two hooked end steel fiber contents (30 kg/m³ and 55 kg / m³), in three equal molding series. The reproducibility was evaluated in an interlaboratory program, with the participation of six independent laboratories, and using the same fiber and contents. The analysis of variance (ANOVA) and the ASTM E691 methodology were applied as a tool to compare the results and to evaluate if there were repetition and reproduction of the test parameters occurred. Together with these tools, an inductive test was used on the reproducibility specimens to verify the scatter of the fiber among them. The results showed that it was possible to obtain repeatability and reproducibility of means for the parameters related to the residual loads. However, the variances are more sensitive than the means, and did not show total repetition when the homogenization of the fibers in the total volume of the concrete is compromised. Moreover, the cracking loads of the test (Pf) were not totally repeatable and reproducible, as they can be affected by the testing machine.
66

Efeitos genéticos e ambientais sobre o intervalo desmame-cio em fêmeas suínas /

Leite, Carla Daniela Suguimoto. January 2009 (has links)
Resumo: A seleção baseada em características reprodutivas tem sido muito empregada em programas de melhoramento genético de suíno. Assim, objetivaram-se avaliar os efeitos ambientais e genéticos que influenciam o intervalo desmame-cio (IDC) e verificar sua influência no número de nascidos total (TL), nascidos vivos (NV) e mortos (NM) em fêmeas suínas. Para análise dos efeitos ambientais, utilizaram-se 8.104 dados da 1ª a 6ª ordem de parição, e, para as estimativas dos parâmetros genéticos, apenas as informações do 1º ao 3º IDC, o que resultou em 6.548 observações, que foram analisadas pelo método REML, utilizando-se modelos uni e multicaracterística. Para este último, considerou-se cada IDC (1º, 2º e 3º) como uma característica distinta. Avaliaram-se, também, as correlações genéticas entre o IDC, TL, NM e idade ao primeiro parto (IPP). Para os fatores ambientais, o modelo incluiu como efeitos fixos rebanho, linhagem, ano (AP) e estação (EP) de parto, e as covariáveis idade da porca ao parto (IDPP), TL e duração da lactação (DL). A DL, na forma linear, e a IDPP, na forma quadrática, influenciaram o IDC. Rebanho, AP e EP foram fontes de variação significativas, enquanto TL e linhagem não o foram. Não foi observada influência do IDC sobre TL, NV, nem sobre NM. A herdabilidade estimada para o IDC pelo modelo de repetibilidade foi baixa. As correlações genéticas entre os IDC (1º, 2º e 3º) foram de moderada a baixa magnitude, evidenciando que o modelo multicaracterística é mais indicado para as estimativas de parâmetro genético nessa população. As correlações genéticas entre IDC, TL e NM, assim como IDC e IPP foram favoráveis à seleção. / Abstract: Selection for reproductive traits has been largely used in swine breeding programs. The aims of this study were to evaluate environmental and genetic effects that affect the weaning-to-estrus interval (WEI) in sows and to assess their influence on litter size (LS), number of live born (LP) and dead born piglets (DP). Data consisting of 8,104 WEI from the 1st to 6th farrowing recorded in two herds were used for environmental analysis, but for estimating the genetic parameters only data from the 1st to 3rd farrowing were used, totalling 6,548 records. Genetic analysis was performed using the REML method with single and multitrait models, where each WEI was considered as a different trait. Genetic correlations among WEI, LS, DP and age at first farrowing (AFF) were also estimated using a multitrait model. For the environmental analysis, the model included as fixed effects the herd, line, and year (YF) and season (SF) of farrowing, and as covariates the sow's age at farrowing (SAF), LS, and lactation length (LL). The effects were linear for LL and quadratic for SAF. The herd, YF and SF were important sources of variation, whereas LS and line were not significant. There were no effects of WEI on the litter traits (LS, LP and DP). The heritability estimated for WEI was low, and genetic correlations among its different intervals were of moderate to low magnitude, evidencing that a multitrait model was more indicated for estimating the genetic parameters for this trait in this population. The genetic correlations between WEI and LS, DP and AFF would be favourable in a selection. / Orientador: Jeffrey Frederico Lui / Coorientadora: Lúcia Galvão de Albuquerque / Banca: Humberto Tonhati / Banca: Joslaine Noely dos Santos Gonçalves Cyrillo / Mestre
67

Regulation of follicular wave pattern in cattle

Jaiswal, Rajesh Shriniwas 04 September 2007
The wave-like developmental pattern of follicles ≥1 mm in temporal relationship with follicle stimulating hormone (FSH) and the existence of 2- and 3-waves of follicular development during an interovulatory interval (IOI) have been clearly defined in cattle. However, information about the developmental pattern of antral follicles <1 mm and the repeatability of the wave pattern (2- or 3-wave IOI) is lacking. Using approaches such as immunization against GnRH (to suppress circulating concentrations of FSH) and histomorphometric study of ovarian tissues collected from cyclic heifers on different days after ovulation, the developmental pattern of antral follicles <1 mm and the role of FSH in their development were studied in heifers. Ultrasonographically acquired follicular data were used to determine the repeatability of 2- and 3-wave patterns and the effect of season on the wave patterns. The ovulatory follicle in 3-wave IOI is exposed to a shorter term high-progesterone environment than that of 2-wave IOI, and it has been argued that the less-aged ovulatory follicle of 3-wave IOI yields a more fertile oocyte than the 2-wave IOI. The developmental competence of oocytes in preovulatory follicles of 2- versus 3-wave IOI was compared using in vivo environments created to mimic short-term low- and high-progesterone environments similar to 2- and 3-wave IOI, respectively. The developmental competence of oocytes in persistent dominant-type follicles was also determined.<p>The vaccination against GnRH attenuated FSH surges but did not suppress the basal circulating concentrations of FSH. The attenuation of FSH surges suppressed the wave-like emergence of follicles ≥4 mm but not of the antral follicles <4 mm. The study revealed an inverse relationship between the mean and peak circulating concentrations of FSH and the number of follicles recruited into ≥1 mm size category. Histomorphometric study revealed that antral follicles <1 mm developed in a wave-like fashion in response to a rise in the circulating concentrations of FSH. After treatment with exogenous FSH, the growth rate of follicles in GnRH-immunized heifers was similar to controls. <p>The duration of IOI was predictive of the wave pattern (i.e., 2- or 3-wave IOI), and the pattern was repeatable within individuals throughout the year. The dominant follicle of Wave 1 in 2-wave IOI had a longer duration of dominance than in 3-wave IOI. Hence, the dominant follicle of Wave 1 may have a primary role in the regulation of 2- and 3-wave patterns. Greater attrition of follicles in 3-wave IOI, due to the emergence of an extra wave compared to 2-wave IOI, may contribute to earlier follicular depletion and onset of reproductive senescence in heifers with primarily a 3-wave pattern. The fertilization capacity of oocytes that were exposed to the short-term low-progesterone environment (i.e., similar to the early growing phase of the ovulatory follicle of 3-wave IOI) was increased, but the developmental competence post-fertilization was not different from oocytes that were exposed to a short-term high-progesterone environment (i.e., similar to the early growing phase of preovulatory follicle of 2-wave IOI). Multiple follicles developed under the prolonged-low progesterone environment, but failed to ovulate.
68

Regulation of follicular wave pattern in cattle

Jaiswal, Rajesh Shriniwas 04 September 2007 (has links)
The wave-like developmental pattern of follicles ≥1 mm in temporal relationship with follicle stimulating hormone (FSH) and the existence of 2- and 3-waves of follicular development during an interovulatory interval (IOI) have been clearly defined in cattle. However, information about the developmental pattern of antral follicles <1 mm and the repeatability of the wave pattern (2- or 3-wave IOI) is lacking. Using approaches such as immunization against GnRH (to suppress circulating concentrations of FSH) and histomorphometric study of ovarian tissues collected from cyclic heifers on different days after ovulation, the developmental pattern of antral follicles <1 mm and the role of FSH in their development were studied in heifers. Ultrasonographically acquired follicular data were used to determine the repeatability of 2- and 3-wave patterns and the effect of season on the wave patterns. The ovulatory follicle in 3-wave IOI is exposed to a shorter term high-progesterone environment than that of 2-wave IOI, and it has been argued that the less-aged ovulatory follicle of 3-wave IOI yields a more fertile oocyte than the 2-wave IOI. The developmental competence of oocytes in preovulatory follicles of 2- versus 3-wave IOI was compared using in vivo environments created to mimic short-term low- and high-progesterone environments similar to 2- and 3-wave IOI, respectively. The developmental competence of oocytes in persistent dominant-type follicles was also determined.<p>The vaccination against GnRH attenuated FSH surges but did not suppress the basal circulating concentrations of FSH. The attenuation of FSH surges suppressed the wave-like emergence of follicles ≥4 mm but not of the antral follicles <4 mm. The study revealed an inverse relationship between the mean and peak circulating concentrations of FSH and the number of follicles recruited into ≥1 mm size category. Histomorphometric study revealed that antral follicles <1 mm developed in a wave-like fashion in response to a rise in the circulating concentrations of FSH. After treatment with exogenous FSH, the growth rate of follicles in GnRH-immunized heifers was similar to controls. <p>The duration of IOI was predictive of the wave pattern (i.e., 2- or 3-wave IOI), and the pattern was repeatable within individuals throughout the year. The dominant follicle of Wave 1 in 2-wave IOI had a longer duration of dominance than in 3-wave IOI. Hence, the dominant follicle of Wave 1 may have a primary role in the regulation of 2- and 3-wave patterns. Greater attrition of follicles in 3-wave IOI, due to the emergence of an extra wave compared to 2-wave IOI, may contribute to earlier follicular depletion and onset of reproductive senescence in heifers with primarily a 3-wave pattern. The fertilization capacity of oocytes that were exposed to the short-term low-progesterone environment (i.e., similar to the early growing phase of the ovulatory follicle of 3-wave IOI) was increased, but the developmental competence post-fertilization was not different from oocytes that were exposed to a short-term high-progesterone environment (i.e., similar to the early growing phase of preovulatory follicle of 2-wave IOI). Multiple follicles developed under the prolonged-low progesterone environment, but failed to ovulate.
69

Comparison Of Compressive Strength Test Procedures For Blended Cements

Ulker, Elcin 01 September 2010 (has links) (PDF)
The aim of this thesis is to twofold, in order to demonstrate the variabilities that can be faced within the compressive strength of blended cements, one blended cement namely CEM IV / B (P-V) 32.5N is selected and the 28-day compressive strength is obtained by 16 different laboratories following TS EN 196-1 standard. Later, to show the variabilities that could be faced by different standards, three different cement types were selected and their compressive strengths are determined following two procedures first with TS EN 196-1, later with similar procedure described in ASTM. The strength of cement is determined by TS EN 196-1 in Turkey that is the same for all types of cements. However, American cement producers use different standards for testing the strength of Portland cement and blended cements. The main difference is the amount of water utilized in producing the cement mortar. It was observed that for Portland and Portland composite cements / there is not any significant difference in between the compressive strength results of cement mortars prepared by both methods. However, for pozzolanic cements, there is much deviance in the compressive strength results of cement mortars prepared by TS EN 196-1.
70

Development capability profiles of selected reverse engineering techniques

Duss, Alexander 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University 2012 / ENGLISH ABSTRACT: Reverse engineering (RE) has emerged as an important tool in the design stages of a product. The demand for better performance of hardware and software has spawned many different technologies that fall under RE. The diversity of technologies is linked to the different application areas of industry. It is critical to understand what the exact capability of each individual technology is, in order to choose the appropriate RE system. The objective of this study is to develop capability profiles of different RE technologies available, such as: Coordinate Measuring Machine, Articulated Arm (Cimcore), Non-contact scanner (GOM), and contact scanner (Renishaw). To achieve the objective, the different characteristics of each technology are measured and quantified. A capability profile can be regarded as defined criteria that represent the performance of a RE technology and in this study, is defined by quantifying the following characteristics:  Accuracy  Repeatability  Speed of Measurement  Work Envelope  User-friendliness. The significance of developing these capability profiles is so that they may be compared to one another. This is important, especially for the accuracy criterion, as each technology is manufactured by a different company, making an acceptable accuracy comparison amongst the different technologies impossible. The study also suggests an evaluation tool which will help a decision maker choose the appropriate technology for a specified objective. Guidelines are also given to potential end users of RE technologies on how they should go about acquiring the right system. On a more general level, the study contributes to research in recent trends, in the RE industry in terms of application, hardware, software and the selection of RE systems. By developing these capability profiles, the study aims to contribute to its value in academia, as well as for industry partners and potential RE end-users. / AFRIKAANSE OPSOMMING: RE het ontwikkel as n belangrike hulpmiddel in die ontwerp fase van ‘n produk. Die aanvraag na beter prestasie van hardeware en sagteware het gelei tot die ontwikkeling van baie verskillende tegnologie. Die diversiteit van die tegnologie gaan hand aan hand met die verskillende toepassings areas in die industrie. Dit is belangrik om die spesifieke eienskappe van elke individuele tegnologie te verstaan om die regte RE sisteem te kies. The doel van hierdie studie is om die vermoë profiele van die verskillende beskikbare RE tegnologie te ontwerp: Coordinate Measuring Machine, Articulated Arm (Cimcore), nie-kontak skandeerder (GOM) en kontak skandeerder (Renishaw). Die verskillende eienskappe van elke tegnologie word gemeet en gekwantifiseer. ‘n Vermoë profiel kan gesien word as ‘n vaste kriteria wat die prestasie van die RE tegnologie verteenwoordig en in hierdie studie word dit gedefinieer deur die volgende eienskappe:  Akkuraatheid  Herhaalbaarheid  Spoed van meeting  Meet volume  Gebruikers-vriendelikheid Die relevansie van die ontwikkeling van hierdie vermoë profiele is dat dit wedersyds vergelyk kan word. Dit is belangrik, spesifiek vir die akkuraatheids kriteria, omdat elke tegnologie by ‘n verskillende maatskappy vervaardig word. ‘n Aanvaarbare akkuraatsheid vergelyking onder die verskillende tegnologie is dus onmoontlik. Die studie stel ook ‘n evaluasie hulpmiddel voor wat die besluitnemer sal lei om die mees toepaslike tegnologie te kies vir die spesiefieke doeleindes. Verder word riglyne aan die potensiele gebruikers van RE tegnologie gegee oor hoe om te werk te gaan om die regte sisteem te kies indien die tegnologie nie in besit is nie. Op ‘n meer algemene vlak dra die studie tot navorsing by deur die nuutste tendense in toepassing, hardeware, sagteware en die keuse van RE sisteme in die RE industrie te beskryf. Deur hierdie vermoë profile te ontwikkel beoog die studie om waarde toe te voeg aan die akademie, vennote in die industrie en potensiele RE gebruikers.

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