L' étude réalisée s'est portée sur la détermination de l’âge à partir d’investigations sur l’alvéolyse humaine.Le manque de fiabilité de l’attache épithéliale comme indicateur d’âge et l’absence de corrélation de la translucidité dentinaire sur dents entières ou coupées ont démontré l'intérêt d'un nouveau modèle odontologique d'estimation de l'âge. Nous avons, pour cela, , recruté une série importante de scanners (500)à visée implantaire assortis d’un questionnaire médico-administratif administré en face à face. Une base équilibrée en terme de sex-ratio et de classes d’âge a été constituée avec comme critère d’inclusion des secteurs dentés et observables. La deuxième phase a consisté à pratiquer des mesures biométriques de la hauteur de perte d’os alvéolaire par rapport au référent classique que constitue la jonction émail Cément. A partir des données relevées, et ajustées sur les variables individuelles et comportementales recueillies dans le questionnaire, nous avons établi une corrélation avec la variable continue, l’âge. Nous avons pu proposer un modèle d’estimation de l’âge alternatif à celui de la méthode odontologique de Lamendin avec une fiabilité identique mais applicable sur des classes d’âges de 25 à 60 ans.Cette méthode a été validée par une étude comparative de trois indicateurs d'erreurs et la formule optimisée par la méthode Bootstrap. Les modèles ont été, ensuite, appliqués sur une série de crânes anciens complets (32) et sur une population contemporaine (50). Enfin, nous avons ouvert la perspective ,à partir du même protocole, d'estimation de l'alvéolyse à partir de l'âge ajusté ou non sur les différentes variables retenues dans l'étude principale. / The study carried out concerned to the determination of the age from investigations on the human alveolar bone loss. The lack of reliability of the tie epithelial as indicator of age and the absence of correlation of the transparency of the dentin on whole or cut teeth demonstrated the interest of a new odontological model of estimation of the age. We have, for it, recruited an important series of scanners (500) for implantological treatment matched by a medical administrative questionnaire administered opposite to face. A base balanced in term of sex-ratio and age groups was established with as criterion of inclusion of the toothed and observable sectors. The second phase consisted in practicing biometric measures of the height of loss of alveolar bone with regard to the classic referent that the junction enamel Cement establishes .From the data, and adjusted on the individual and behavioral variables collected in the questionnaire, we established a correlation with the continuous variable, the age. We were able to propose a model of estimation of the age in that of the odontological method of Lamendin with an identical but applicable reliability on age groups from 25 to 60 years. This method was validated by a comparative study of three indicators of errors and the formula optimized by the Bootstrap method. The models were, then, applied to a series of ancient complete skulls (32) and to a contemporary population (50). Finally, we opened the prospect, from the same protocol, from the estimation of the alveolar bone loss from the adjusted age or not on the various variables held) in the main study.

Scatter and random coincidences are of significant concern in Positron Tomography because they lead to the misrepresentation of the activity distribution in the final image. In this regard, interplane septa have long been used in ring positron tomographs to suppress the acquisition of photons oblique to the scan planes. The septa extend from the face of the detector array to the edge of the field of view. Not only do the septa block photons scattered oblique to the scan planes and singles originating in different planes, but they also result in a decreased count rate sensitivity of the tomograph to true coincidence photons. In this work, the Monte Carlo technique has been employed to study the effect of "septa shadowing" with respect to septa length in order to determine an optimal septa length. Sensitivity parameters have been derived by the use of Noise Equivalent Count (NEC) Rate Analysis, as well as count rate sensitivity analysis in order to balance the counting and imaging performance of the system. In addition, energy spectra, sinogram profiles and scatter fraction results are presented to quantify the effects of septa length on the trues, scatter and randoms contributions of the data collected by the scanner. It is concluded that the highest NEC rate is achieved with positron tomographs with no septa and operating in 3D mode. / Thesis / Master of Science (MS)

This study was conducted to evaluate the effect of communication and information on the potential adoption of optical scanners by hospital pharmacy directors. The study used a randomly selected national mail survey of 600 hospital pharmacy directors. A response rate of 64.17% was attained and the instrument was determined to have adequate reliability. Believability of optical scanner assessment information was compared between directors with high and low optical scanner familiarity. Directors with high familiarity rates the information's influence on their decision to adopt significantly higher than directors with low familiarity. Directors were also asked to rate the importance of the source of information and the optical scanner characteristics when making their decision to adopt. Directors with high familiarity rated management sources, administrative uses and time-savings higher and cost lower in importance. The survey revealed that 18.96% of the respondents were currently using optical scanners, primarily for inventory control.

Thesis (MSc (Physics))--University of Stellenbosch, 2005. / The extremely high light intensities produced by lasers and the increasing use of lasers highlights the need for measures to prevent damage to materials due to exposure to high intensity laser light. In particular it necessitates the development of systems to protect optical sensors, including the human eye. In this work optical limiters were investigated as a system for protecting sensors. An optical limiter transmits ambient light, but absorbs high intensity light. This makes it ideal for protecting sensors from laser radiation, since it allows the sensor to operate unhindered at design intensities while protecting it from harmful high intensity radiation. There are various mechanisms used for optical limiting, and in this work the nonlinear absorption and the nonlinear index of refraction changes of materials were investigated. A facility was established to measure the nonlinear optical properties of a variety of materials, in order to classify them as possible optical limiters. This entailed creating a so called Zscan setup, which enabled us to measure the nonlinear absorption coefficient and the nonlinear index of refraction of a material. The theory and the design of the setup are discussed and experimental results obtained using this setup are presented. A wide variety of material types were investigated to show the versatility of the experimental setup. These included C60, which was analyzed in solution; ZnO which is a crystal; CdS quantum dots in solution; and poly(dioctyl-fluorene), which is a large polymer molecule, in solution. The materials investigated in this work were chosen based on their known strong nonlinear optical properties. Emphasis was placed on measuring the nonlinear absorption coefficients since it was the dominant optical limiting effect of the materials under investigation. The results obtained displayed the same trends as published results and it shows that the established facility was capable of measuring the nonlinear properties of these samples. The experimental limitations of the setup were determined, and critical experimental parameters were identified for measurements of this nature. Improvements to the experimental facility are suggested to improve the accuracy of future measurements.

Com o advento da Fotogrametria Digital nos últimos anos, a numerização de fotogramas através de scanners tornou-se uma etapa obrigatória nos processos fotogramétricos. Este trabalho tem como objetivo principal apresentar uma técnica de calibração de scanners, utilizando-se uma Transformação Afim de seis parâmetros com superabundância de observações. A metodologia proposta foi aplicada em três modelos de scanners diferentes e os resultados obtidos, nas condições experimentais, demonstraram uma boa adequação do modelo matemático proposto. / With the approach of Digital Photogrammetry the last years, the digitizing of pictures through scanners has been an obligatory stage in photogrammetric procedures. The main purpose of this paper is to show a scanners calibration technique, by using an affine six-parameters transformation with redundancy. The proposed methodology was applied in three different models of scanners, and, in experimental states, the results gotten showed a good fit of the proposed mathematic model.

Com o advento da Fotogrametria Digital nos últimos anos, a numerização de fotogramas através de scanners tornou-se uma etapa obrigatória nos processos fotogramétricos. Este trabalho tem como objetivo principal apresentar uma técnica de calibração de scanners, utilizando-se uma Transformação Afim de seis parâmetros com superabundância de observações. A metodologia proposta foi aplicada em três modelos de scanners diferentes e os resultados obtidos, nas condições experimentais, demonstraram uma boa adequação do modelo matemático proposto. / With the approach of Digital Photogrammetry the last years, the digitizing of pictures through scanners has been an obligatory stage in photogrammetric procedures. The main purpose of this paper is to show a scanners calibration technique, by using an affine six-parameters transformation with redundancy. The proposed methodology was applied in three different models of scanners, and, in experimental states, the results gotten showed a good fit of the proposed mathematic model.

Thesis (Ph. D.)--University of Chicago, The Graduate School of Business, Aug. 2003. / Includes bibliographical references (p. 54-57). Also available on the Internet.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 204-210). Also available on the World Wide Web.

Thesis (M.S.)--Rochester Institute of Technology, 1989. / Includes bibliographical references (leaves 57-61).

Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 83-86).