by Siu-Yuk Yeung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 96-102). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.5 / Chapter 1.1 --- Shape recovery techniques --- p.5 / Chapter 1.2 --- Shape from Shading algorithms --- p.8 / Chapter 1.2.1 --- Some developments on surface reflection --- p.9 / Chapter 1.2.2 --- Some developments on computing methods --- p.11 / Chapter 1.2.3 --- Some developments on light source model --- p.12 / Chapter 1.3 --- Proposed algorithms in this thesis --- p.13 / Chapter 1.4 --- Thesis outline --- p.14 / Chapter 2 --- Camera and surface reflectance models for SFS --- p.15 / Chapter 2.1 --- Camera models for SFS --- p.16 / Chapter 2.1.1 --- Pinhole camera model and perspective projection --- p.17 / Chapter 2.1.2 --- Approximations of perspective projection --- p.20 / Chapter 2.2 --- Surface reflectance models for SFS --- p.22 / Chapter 2.2.1 --- Lambertian surface model --- p.23 / Chapter 2.2.2 --- Bidirectional Reflectance Distribuction Function --- p.23 / Chapter 2.3 --- Summary --- p.25 / Chapter 3 --- Review of some related SFS algorithms --- p.26 / Chapter 3.1 --- The SFS algorithm proposed by Bichsel and Pentland --- p.27 / Chapter 3.1.1 --- Determine surface height with a minimum downhill principle --- p.28 / Chapter 3.1.2 --- Implementation on a discrete grid --- p.30 / Chapter 3.2 --- The SFS algorithm proposed by Kimmel and Bruckstein --- p.31 / Chapter 3.2.1 --- Level set propagation --- p.32 / Chapter 3.2.2 --- Problem formulation --- p.33 / Chapter 3.2.3 --- Equal height contour propagation using level set method --- p.35 / Chapter 3.3 --- Summary --- p.36 / Chapter 4 --- Multiple extended light source models for SFS --- p.38 / Chapter 4.1 --- Three extended light source models for SFS --- p.40 / Chapter 4.1.1 --- Rectangular light source model --- p.40 / Chapter 4.1.2 --- Spherical light source model --- p.43 / Chapter 4.1.3 --- Cylindrical light source model --- p.48 / Chapter 4.2 --- SFS for an extended light source --- p.53 / Chapter 4.3 --- Multiple extended light source model --- p.53 / Chapter 4.4 --- Simulation and experiment result --- p.54 / Chapter 4.5 --- Error Analysis --- p.55 / Chapter 4.5.1 --- Descriptions of the error --- p.55 / Chapter 4.5.2 --- Errors for different light models --- p.55 / Chapter 4.6 --- Summary --- p.57 / Chapter 5 --- Global SFS for an endoscope image --- p.70 / Chapter 5.1 --- Introduction --- p.71 / Chapter 5.2 --- Local SFS algorithm for endoscope image --- p.73 / Chapter 5.2.1 --- Imaging system and brightness formulation --- p.74 / Chapter 5.2.2 --- Equal distance contour propagation and shape reconstruc- tion --- p.75 / Chapter 5.3 --- Global SFS algorithm for endoscope image --- p.76 / Chapter 5.3.1 --- A global shape from shading algorithm for a parallel light --- p.77 / Chapter 5.3.2 --- The relationship between depth map and distance map --- p.78 / Chapter 5.3.3 --- A global shape from shading algorithm for endoscope image --- p.78 / Chapter 5.4 --- Simulations and experiments results --- p.83 / Chapter 5.5 --- Summary --- p.86 / Chapter 6 --- Summary and conclusion --- p.87 / Chapter 6.1 --- Problems tackled in this thesis --- p.87 / Chapter 6.2 --- Discussion on future developments --- p.88

Storage ring light sources are in use around the world operating as high brightness photon sources from the infrared to the X-ray photon regimes. Whilst modern light source designs achieve horizontal emittances in the few-nm range, they are only diffraction limited in the vertical plane with emittances as low as 10~pm-rad. To achieve fully diffraction limited light sources in the X-ray regime requires a fundamental change in the design of such machines. Many such designs have been proposed based on the multi-bend achromat (MBA) lattice, which have been shown to achieve the required emittance reduction. However MBA lattices typically have a reduced dynamic acceptance, and consequently shorter beam lifetimes. Whilst this can be ameliorated somewhat through the use of top-up injection schemes, many issues still remain. In this thesis we explore one possible alternative to the multi-bend achromat (MBA) paradigm: the stacked storage ring. We propose a storage ring consisting of two synchrotrons joined via a static magnetic vertical transfer line. One of the rings has a reduced emittance through the use of high field damping wigglers, whilst the other is used for standard user experiments. The cumulative emittance of the combined ring structure is a function of the emittances of the two rings. The stacked ring approach allows for a reduction in the beam emittance without a consequent increase in the machine footprint, as in the case of the MBA lattice. Additionally, we may use the more relaxed lattice structures popular in currently operating 3rd generation light sources to maintain a reasonable dynamic acceptance even with the reduced emittance. We apply the stacked storage ring concept to the design of a low emittance 700~MeV compact light source for low energy vacuum ultraviolet photon output. The desirability of such a low energy photon source for UK science has previously been explored in depth. We examine the design of such a light source based around a strong damping stacked storage ring in the presence of Touschek and Intra-Beam scattering whilst analysing the effects on the dynamic properties of the lattice. We also apply the stacked ring concept to two lattices designed to operate in the high energy X-ray region of the photon spectrum and investigate the potential advantages in this regime, including as an adjunct to further improve proposed MBA concepts.

Thesis (M.S.)--Ohio University, March, 1999. / Title from PDF t.p.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Graham, Samuel; Committee Member: Joshi, Yogendra; Committee Member: Kumar, Satish. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The thesis deals with the design of a goniophotometer and the GUI (Graphical User Interface), capable of evaluating the photometric parameters of light sources and luminaires. The introduction contains theoretical information about photometry, photometric parameters, light sources, lamps, as well as the theory of measuring these parameters, and basic globally used data formats, designed to store the parameters of light sources. The core of this thesis, then describes the hardware, that makes up the proposed device, and the software needed to control the measurement process, visualization and storing the results. The conclusion is an evaluation of the functionality of the described device, and the measurements that were mediated by it, and an overall summary of the results achieved.

The main goal of the diploma thesis is DWDM simulation of optical network, defined by recommandation ITU-T. Optical network includes 16 communication channels with length of fiber 50 km. Each channel have to be set with bandwith 50GHz and Bit rate with minimal value 10Gbit/s. The final simulation model includes 8 types of modulation techniques. The result of the thesis is comparison modulation techniques in terms of usability of bandwith and comparison of the quality of transfer

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Technological developments in the area of high power LED light sources have enabled their utilization in general illumination applications. Along with this advancement comes the need for progressive thermal management strategies in order to ensure device performance and reliability. Minimizing an LED's junction temperature is done by minimizing the total system's thermal resistance. For actively cooled systems, this may essentially be achieved by simultaneously engineering the conduction through the heat sink and creating a well-designed flow pattern over suitable convective surface area. While such systems are routinely used in cooling microelectronics, their use in LED lighting systems encounter additional constraints which must be accounted for in the design of the cooling system. These are typically driven by the size, shape, and building codes involved with the lighting industry, and thus influence the design of drop-in replacement LED fixtures. Employing LED systems for customary down-lighting applications may require shrouded radial fin heat sinks to increase the heat transfer while reducing the space requirement for active cooling. Most lighting is already in some form of housing, and the ability to concurrently optimize these housings for thermal and optical performance could accelerate the widespread implementation of cost-efficient, environmentally-friendly solid-state lighting. In response, this research investigated the use of conical, cylindrical, square, and pyramidal shrouds with pin/radial fin heat sink designs for the thermal management of high power LED sources. Numerical simulations using FLUENT were executed in order to account for details of the air flow, pressure drop, and pumping power, as well as the heat transfer and temperature distributions throughout the system. The LEDs were modeled as a distributed heat source of 25 - 75 W on a central portion of the various heat sinks. Combinations of device junction temperature and pumping power were used to assess the performance of shrouded heat sink designs for their use in air-cooled, down-lighting LED fixtures.

Thesis (M.S.)--University of North Carolina Wilmington, 2008. / Title from PDF title page (October 20, 2008) Includes bibliographical references (p. 58-60)

Made available in DSpace on 2014-06-11T19:27:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-29Bitstream added on 2014-06-13T18:56:44Z : No. of bitstreams: 1 magno_aff_me_arafo.pdf: 677357 bytes, checksum: eeda74e2c1742441d13f507c4660bb18 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo dessa pesquisa foi avaliar in vitro a fotopolimerização de bráquetes vestibulares e linguais utilizando o arco de plasma, o diodo emissor de luz (LED) e a luz halógena convencional em tempos diferentes. Dois artigos científicos foram redigidos e utilizados para a avaliação dos propósitos apresentados. Na análise por vestibular, não houve diferenças entre o uso da luz arco de plasma por 6 segundos, do LED por 10 segundos e da luz halógena por 40 segundos. A luz arco de plasma por 3 segundos e o LED por 5 segundos demonstraram resistências ao cisalhamento iguais entre si e significantemente menores em relação às da luz halógena (p<0,001). Os resultados do índice de adesivo remanescente (IAR) mostraram que a interface de fratura dente/bráquete ocorreu com maior freqüência em todos os grupos, entretanto, os dados não puderam ser avaliados estatisticamente em função da distribuição dos escores. Na análise por lingual, as três fontes de luz mostraram-se diferentes entre si (p<0,001). A luz arco de plasma em 6 segundos obteve a menor média de resistência ao cisalhamento, seguida do LED em 10 segundos, que por sua vez apresentou menor média em relação à luz halógena em 40 segundos. O teste quiquadrado demonstrou não haver diferença significativa nos escores do IAR quando empregados os diferentes tipos de luz. Foi concluído, por vestibular, que a luz arco de plasma e o LED podem ser utilizados por tempos reduzidos em relação à luz halógena, sem perda de resistência ao cisalhamento, mas com limites para esta redução. Nos testes por lingual, a luz arco de plasma obteve resistências menores que o LED, o qual demonstrou resistências menores que a luz halógena, porém, estas diferenças não afetaram o padrão de descolagem. / The objective of this in vitro study was to evaluate the variation of temperature and Knoop microhardness on enamel surface during the bleaching process whith 35% hydrogen peroxide under irradiation by halogen light whit the wavelength of 400 to 500nm (HL), LED whit the wavelength of 460 to 480nm and high intensity diode laser LED whit the wavelength of 810nm (LD) on extracted human teeth. Initially were investigated the variation of surface temperature (infrared thermography) and the temperature of the interior of the pulp chamber (thermocouples) in human mandibular incisors when subjected to dental bleaching with 35% hydrogen peroxide in the colors red (HP) and green(HPM) irradiated by: HL and LED. Four groups (n = 10) were divided according to the bleaching gel and light source. The results were submitted to the analysis of variance and Tukey test (p < 0.05). The mean values and standard deviations of the temperature increase inside the chamber pulp with HL were 4.4 ± 2.1 °C using HP and 4.5 ± 1.2 °C using HPM; while in LED groups, were 1.4 ± 0.3 °C to HP, and 1.5 ± 0.2 °C using HPM. For all surface temperatures, the maximum variation of the groups irradiated with HL was 6.5 ± 1.5 °C to HP and 7.5 ± 1.1 °C using HPM; while for the groups using LED, were 2.8° ± 0.7 °C using HP, and 3 ± 0.8 °C for HPM. There were no statistical difference between the increase of pulp and superficial temperature between groups using the various gels (p < 0.05). Mean temperatures were significantly higher for groups using HL compared with those irradiated with LED (p < 0.05). Was investigated the variation of surface temperature and thus given the time-delay to hit the critical variation of temperature (5.5 °C for the pulp chamber and 10 °C for periodontal). Forty-five human inferior incisors were divided into 3 groups and submitted to dental bleaching using HP and activated by HL,...(Complete abstract, click electronic access below)