Code V, an optical design program, was used to design a lens for a three-dimensional mapping application. The purpose of the lens system is to project an array of spots of light onto the object of interest. The size of the projected spots can be used to determine the distance from the lens to the object. The design criterion for this system was a 2% accuracy of position with a two lens system. The use of anamorphic and aspheric surfaces was also investigated as a means to improve the design performance.

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Ljusdesign är en viktig faktor i media som t ex spel, film och inredningsdesign. Att tänka i interaktions designs banor är inte alltid prioriterat när man skapar ett rum med ljus. Användarorienterade termer borde vara mer av en standard för designern eller ljussättaren för att uppnå den bästa möjliga upplevelsen för betraktaren när denne åskådar en scen/rum med någon form av ljussättning. Detta arbete kommer att beskriva det onlineverktyg som jag har skapat, designprocessen bakom den samt hur jag använt den för att söka efter människors känslomässiga respons på olika ljusvinklar projicerade mot människor eller objekt. Verktyget består av ett ansikte, fem uppgifter samt en ljuskälla. Ljuskällan rörs fritt runt ansiktet och uppgifterna tolkas helt individuellt av varje användare. Ett exempel på en uppgift är: Designa en djävul! Det finns inga rätt eller fel när användaren designar, det är helt och hållet upp till varje testperson hur de tycker att en djävul ser ut med endast en ljuskälla/ljusvinkel. Resultaten markeras ut på en så kallade ”facemap” för att visualisera statistiken bakom testerna. Resultaten som görs online av användare är analyserade och förklarade hur de används i studien för att försöka skapa ett nytt sätt att tänka inom ljusdesign. Detta med anledning att förbättra ljusdesign i filmer, foto och slutligen spel. Denna forskning samt prototyp kommer även att stödja fotografer och scensättare i deras artistiska skapande. / Lighting design is an important factor in media such as games, movies and interior design. Interaction design thinking is not always the priority when designing a space with light. The user oriented terms of thinking should be more of a standard for the designer, enabling them to create the highest possible experience for the beholder when viewing a scene with a light set-up. This paper will explain the online test tool I have created, the design process behind it, and how I used it in the search for peoples emotional responses to different light angles projected onto humans or objects. The tool consists of a single face, five tasks and one light source. The light source is moved freely around the face and the tasks given are interpreted individually by each user. An example of one task is: Design a devil! There is no right or wrong when designing, it is completely up to each test person how they think a devil look like with only one light source/light angle. The results are mapped out on a “Facemap” to visualize the statistic outcome. The results from user test done with my tool online are analysed and explained how they are used in a study trying to create a new way of thinking when it comes to lighting design. All with the purpose of enhancing lighting design in movies, still images and eventually games. This research and prototype will also support photographers and stage coordinators when creating their sets.

Light-frame wood construction is frequently used in the U.S. High wind events, such as hurricanes, may cause severe damage to these structures by breaking the roof envelope. This study focuses on computing reliability indices of roof sheathing panels exposed to high wind events while considering a time and spatially varying wind load. A procedure is developed that links probabilistic and dynamic finite element analysis codes. The results show that a few critical panels are most susceptible to damage, while most panels have significantly higher reliability indices than previous studies based on simplified analyses have shown. By setting a target reliability index, panel nail spacing can be adjusted to provide a more uniform level of safety over the entire roof.

Visible light communication (VLC) systems take advantage of ubiquitous light-emitting diodes (LED) and leverage existing illumination infrastructure to provide broadband optical communication links. Multiple-input multiple-output (MIMO) VLC systems are among the well studied topics in VLC research. However, most traditional MIMO VLC systems require accurate alignment and have to adjust to different magnifications at various link distances. Consequently, the alignment and calibration modules increase the complexity of the receiver structures. A pixelated MIMO VLC system is introduced in this thesis, which transmits a series of time-varying coded images that can be received and decoded by commercial digital cameras. Using a convex lens placed in front of the transmitter at its focal length, the system exploits the Bokeh effect to obtain fixed-scale images at all link distances. Compared with traditional pixelated MIMO VLC systems, which send information directly in space, this spatial-angular mapping system sends information in different angles instead. In contrast to the complex receiver structures in traditional setups, the proposed system can capture fixed-scale images with a simple receiver requiring no re-focusing as the camera moves. The channel model of the system is measured and modeled and a rateless code is applied to track the truncation of receive images for various link ranges and angular offsets. A proof-of-concept optical communication system is implemented with an LCD display and a high speed CMOS camera. Performance of the system is measured and analysed. The experimental system can achieve a throughput of approximately 10 bit per frame over 90 cm. This fixed-scale pixelated MIMO wireless optical communication system provides a less expensive option for short-range indoor broadcasting optical links and inter-vehicle communications due to its mobility, stability and simpler receiver structure compared to traditional designs in different working conditions. / Thesis / Master of Applied Science (MASc)

Hundreds of years after exploding, the original light from a supernova can still be observed in the form of light echoes. This light scatters off interstellar dust and is re-directed back toward Earth; due to the extra travel time, we observe the echo after the initial outburst. At some time t after observing the outburst, the surface of equal travel paths defines an ellipsoid with Earth and the supernova at the foci. If dust intersects this ellipsoid it is possible to scatter the light and produce an echo. In this thesis, I develop a relative probability model for the detection of supernova light echoes based on the physical characteristics of interstellar dust and absorption near the Galactic plane. This model includes a dust scattering function, distribution (scale height) of dust in the Galaxy, the dilution of echo flux with distance, and absorption along the supernova-dust-Earth travel paths. I have tested the model's predictions against observations and compared it with a prior survey strategy based on IRIS (re-processed IRAS) maps. Currently the IRIS-based strategy is more effective at selecting good paintings but its detection rate is only around 5%, highlighting the elusiveness of echo appearances. This work considers six historical supernovae in the Milky Way, all of which exploded in the pre-telescopic era (with the possible exception of Cas A) and were recorded as "guest stars" in astronomy records from Asia, Europe, and the Middle East. Their light echoes could give us information on these historically significant events and an opportunity to simultaneously study a supernova in outburst and several hundred years later. Early investigations suggest that the distribution of CO in the Galaxy may anti-correlate with the best paintings for light echoes; if a CO-echo link can be established, this would be useful in future light echo surveys. / Thesis / Master of Science (MSc)

<p>Silicon oxide films (oxygen-rich or silicon-rich) doped with various rare-earth (RE) [cerium (Ce), terbium (Tb), europium (Eu) and erbium (Er)] elements have been by deposited by electron cyclotron resonance plasma-enhanced chemical vapour deposition (ECR-PECVD). The successful in-situ incorporation of high concentrations of RE elements has been confirmed by Rutherford backscattering spectrometry (RBS), and the optical properties of the films were analyzed by Photoluminescence (PL) spectroscopy.</p><p> Ce, Tb, Eu and Er related emission was observed from the films with corresponding doping and was found to be sensitive to RE concentration, the presence of Si nanoclusters (Si-ncs) and annealing induced structural evolution. The significant enhancement of Ce^3 + emission in Ce-doped oxygen-rich films under annealing in flowing N2 at 1200 °C was found to be related to the formation of cerium silicate whose presence was confirmed by Fourier transform infra-red (FTIR) spectra and high-resolution transmission electron microscopy (HR-TEM) images. The observation of intense Tb^3+ emission from Tb-doped oxygen-rich films under nonresonant excitation revealed the presence of indirect excitation processes. The organic ligands introduced from the Tb(tmhd)3 precursor during deposition was considered as the possible sensitizer. The presence of Si-ncs in Ce or Eu-doped silicon-rich films resulted in the quenching of both RE and Si-ncs PL, while in Tb or Er-doped silicon-rich films the coupling between Si-nes and RE ions can excite RE-related emission efficiently. The formation of Si-ncs with sizes of 2-3 nm in Tb-doped silicon-rich films under annealing in flowing N2 at 1100 and 1200 °C was revealed by HR-TEM images.</p> / Thesis / Master of Applied Science (MASc)

Fluorescence (F), DCMU-enhanced fluorescence (F^DCMU) and a ratio of these two measurements (F ratio) were found to be useful indicators of light history but not physiological condition of natural phytoplankton assemblages. Changes in the fluorescence properties of unialgal continuous and batch cultures at different growth rates and following nutrient addition were observed only during nutrient starvation. Nutrient deficiency in Lake Ontario was not revealed either by seasonal patterns of fluorescence or by short term changes in the F ratio following nutrient additions. This result however is not conclusive evidence of nutrient sufficiency because of the insensitivity of the fluorescence ratio as an indicator of growth rate. The depression of F and F^DCMU observed in surface waters of Lake Ontario occurred during conditions of high light and low mixing rates. The result suggests that ''photoinhibition" of photosynthesis as measured by conventional primary productivity techniques, may occur in nature only under these particular conditions. A general relationship between temperature gradients or water column stability and the difference in fluorescence between 1 and 10 meters was observed. This relationship was due to both vertical structure in the assemblage and the physiological effect of light on fluorescence. Diurnal patterns of fluorescence were found to be due to the physiological effect of light on fluorescence rather than a circadian rhythm. The physiological effect was dependent on both the duration and intensity of exposure of the cells to light as well as the sensitivity of the assemblage to light. Differences were associated with seasonal changes in species composition with spring and winter populations exhibiting the greatest sensitivity. / Thesis / Master of Science (MSc)

Cucurbita maxima and Cucurbita andreana are closely related species; however, the calcium phytate levels of the Cucurbita seeds differ significantly. Hybridization of the two Cucurbita species is difficult to achieve. The aim of my research was to extensively study the structure of C. maxima and C. andreana pollen and determine whether the pollen of the species differed in their elemental content. This thesis entails the most comprehensive study of the structure, chemical composition and elemental content of the pollen from a dicot plant. This study of Cucurbita pollen required the use of various light microscopy, electron microscopy and elemental analyses techniques. Histochemical stains revealed information about the chemical structure of pollen and pollen storage reserves. The primary storage reserve of Cucurbita pollen consisted of starch. Additional storage reserves consisted of protein, small amounts of lipids and mineral reserves. Additional studies of the external and internal structures of the Cucurbita pollen were carried out with transmission electron microscopy and scanning electron microscopy respectively. Preparation of sections of pollen for electron microscopy was difficult. Sectioning problems arose due to the thick pollen wall, the density of pollen cytoplasm, and inadequate infiltration of epoxy resin into pollen during processing. C. maxima and C. andreana pollen grains were fixed anhydrously because water-soluble phytates such as potassium phytate are extracted by aqueous fixatives . The cytoplasm of both species contained many small electron-dense globoid particles. Globoid particles were observed in sections of pollen and in samples of ground pollen. Elemental analysis of globoid particles from Cucurbita pollen was carried out, for the first time, with energy dispersive X-ray (EDX) analysis. EDX analysis spectra of globoid particles from C. maxima and C. andreana pollen were compared. Spectra of Cucurbita pollen globoid particles were similar to spectra from phytate deposits in seeds. EDX analysis of globoid particles of pollen revealed that the globoid particles contained mainly Mg, P and K. EDX analysis spectra of globoid particles of sections of Cucurbita pollen revealed that water soluble materials, likely K phytate, were extracted from sections cut onto water-filled microtome boats. Pollen sections cut onto absolute ethanol-filled microtome boats experienced less extraction of water soluble materials from the sections. Neutron activation analysis of whole pollen grains revealed that the individual concentrations of Mg, K, Ca and P were not significantly different from species to species. The elemental analyses results strongly suggest that phytate is stored in globoid particles of Cucurbita pollen. / Thesis / Master of Science (MS)

Thesis / Master of Science (MS)