En la presente investigación se tiene como objetivo principal aproximarse desde una mirada basada en la percepción cromática, a los diversos elementos estructurales presentes en los gorros de cuatro puntas policromos del norte de Chile, Período Medio, seleccionados de la colección del Museo Chileno de Arte Precolombino de Santiago. Como material de análisis se estudia: la elección, cantidad, aplicación, combinación y distribución de los colores, la división o partición del espacio representacional, las figuras geométricas y la iconografía; y se establecen patrones de color y articulaciones entre cromatismo y estructura. Se parte de la premisa ya establecida (Cieza de León, 1550; Guaman Poma de Ayala, 1613; Bennet & Bird, 1449; Murra, 1975; Cereceda, 1978; Silverman-Proust 1983, 1986, 1994; Berenguer, 1993, 2006) de que la indumentaria para el hombre precolombino cumplía un rol específico, siendo vehículo de comunicación de identidad cultural, propia para cada pueblo. Dentro de la vestimenta, toman importancia los tocados3, considerados elementos identitarios, destacándose entre ellos los gorros de cuatro puntas policromos, los cuales distinguían a su portador y señalaban poder, posición y rol social. Estas prendas eran asociadas a personajes de de gran prestigio, probablemente miembros de una elite. Esta tesis se orienta a develar, mediante análisis pertinentes, que el tratamiento cromático contribuye a conformar el rol comunicativo identitario y jerárquico. Considerando que en la elección y aplicación del colorido, que hizo el tejedor, en la estructura formal de las piezas textiles, el color tuvo un rol que excedió la simple colocación automática de los matices.

Abstract The purpose of this thesis is to present a case study of the development, implementation and performance analysis of a color-based visual surface inspection method for wood properties. The main contribution of the study is to answer the need of design strategies, performance characterization methods and case studies in the field of automated visual inspection, and especially wood surface inspection. In real time color-based inspection, the complexity of the methods is important. In this study, defect detection and recognition methods based on color histogram percentile features are proposed. The color histogram percentile features were noticed to be able to recognize well wood surface defects with relatively low complexity. A common problem in visual inspection applications is the collection and labelling of training material since human made labellings can be errorneous. Further, the classifiers are relatively static when once trained, thus offering only little possibilities for adjusting classification. In the study, a self-organizing map (SOM) -based approach for classifier user interface in visual surface inspection problems is introduced. The approach relieves the labelling of training material, simplifies retraining, provides an illustrative an intuitive user interface and offers a convenient way of controlling classification. The study is illustrated with four experiments related to the method development and analysis. In the first experiment, a simulator environment is used for determining the relationship of the defect detection and recognition and grading accuracy. The second experiment considers the suitability of different color spaces for wood defect recognition under changing illumination. RGB color space gives the best results compared to grey-level and other color spaces. The third experiment presents the experimental wood surface inspection setup implementing the method developed in this study. Comparative performance analysis results are presented and the difficulties, mainly caused by segmentation of the defects, are discussed. The fourth experiment demonstrates the suitability of the method for parquet sorting and shows the potential of the non-segmenting approach.

Traditional Marxist historical materialism employs a material analysis that privileges how capitalism interacts with subject formation and has been used in recent historicizations of sexuality. This paper understands that line of analysis to be gendering, racializing, and pathologizing and examines LGBTQ history as a starting point to decenter capitalism from the analysis. Using Roderick Ferguson's "queer of color" critique, this paper maintains that more specifically, history should attend to the emergence of surplus populations which capitalism keeps hidden. Under the umbrella of queer of color critique, migration studies, transnational perspectives, and the destabilizing nature of queer theory all have the capacity to provide a fuller view of sexual difference and the histories of LGBTQ and other surplus populations. Furthermore, a legal framework provides an opportunity to take theory into practice by examining legislation with the analytical scope of queer of color and from an anti-capitalist vantage point.

Master of Science / Department of Animal Sciences and Industry / John A. Unruh / The objective of our study was to explore relationships between Japanese color score (JCS) and pork-quality attributes and develop equations to predict JCS. Pork carcass traits in population one (n = 781) was used to develop prediction equations and population two (n = 684) was used to test the equations for accuracy. Pearson's correlation coefficients found firmness, ultimate pH, drip loss percentage, L*, a*, b*, hue angle, and chroma were significantly (P < 0.01) correlated to JCS. Correlation loading found 96% of the variation in firmness, pH, drip loss percentage, L*, a*, b*, and hue angle explained 81% of the variation in JCS. Three prediction equations were developed using these traits. Averages for population one traits were used to develop the initial prediction equations. Predicted JCS, which fell within [plus or minus]0.25 of the actual JCS, were retained and multiple linear regression (MLR) was run, resulting in the first prediction equations. Data from population two were then used to evaluate the success of these equations. Equation one using firmness, pH, drip loss percentage, L*, a*, b*, and hue angle was: JCS = 12.698 – (0.00007199 x drip loss) + (0.09008 x pH) – (0.01128 x firmness) – (0.226 x L*) + (0.06923 x a*) – (0.0201 x b*) + (0.02143 x hue angle); r[superscript]2 = 0.916. For the test population, 98.53 and 67.25% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. The second prediction equation, developed utilizing instrumental color measures of L*, b*, and hue angle was: JCS = 15.255 – (0.259 x L*) – (0.213 x b*) + (0.02518 x hue angle); r[superscript]2 = 0.931. For test population, 92.40 and 55.70% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. The third prediction equation developed utilizing L*, a*, and b* was: JCS = 12.920 – (0.219 x L*) + (0.07342 x a*) – (0.02166 x b*); r[superscript]2 = 0.906. For test population, 97.80 and 68.22% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. All prediction equations predicted 92% or more of the JCS observations within [plus or minus]0.50 and would be useful when sorting pork carcasses for export to valuable Asian markets. The second and third prediction equations would be advantageous as they require fewer measurements and could be more rapidly collected.

We present a novel Vertical External Cavity Surface Emitting Laser (VECSEL) cavity design which makes use of multiple interactions with the gain region under different angles of incidence in a single round trip. This design allows for optimization of the net, round-trip Group Delay Dispersion (GDD) by shifting the GDD of the gain via cavity fold angle while still maintaining the high gain of resonant structures. The effectiveness of this scheme is demonstrated with femtosecond-regime pulses from a resonant structure and record pulse energies for the VECSEL gain medium. In addition, we show that the interference pattern of the intracavity mode within the active region, resulting from the double-angle multifold, is advantageous for operating the laser in CW on multiple wavelengths simultaneously. Power, noise, and mode competition characterization is presented.

M.Sc. / Within the field of Graph Theory the many ways in which graphs can be coloured have received a lot of attention over the years. T.R. Jensen and B. Toft provided a summary in [8] of the most important results and research done in this field. These results were cited by R. Diestel in [5] as “The Four Colour Problem” wherein it is attempted to colour every map with four colours in such a way that adjacent countries will be assigned different colours. This was first noted as a problem by Francis Guthrie in 1852 and later, in 1878, by Cayley who presented it to the London Mathematical Society. In 1879 Kempe published a proof, but it was incorrect and lead to the adjustment by Heawood in 1890 to prove the five colour theorem. In 1977 Appel and Haken were the first to publish a solution for the four colour problem in [2] of which the proof was mostly based on work done by Birkhoff and Heesch. The proof is done in two steps that can be described as follows: firstly it is shown that every triangulation contains at least one of 1482 certain “unavoidable configurations” and secondly, by using a computer, it is shown that each of these configurations is “reducible”. In this context the term “reducible” is used in the sense that any plane triangulation containing such a configuration is 4-colourable by piecing together 4- colourings of smaller plane triangulations. These two steps resulted in an inductive proof that all plane triangulations and therefore all planar graphs are 4-colourable.

M. Phil. / Please refer to full text to view abstract / Prof. J.T. Ferreira

Doctor of Philosophy / Department of Animal Sciences and Industry / John M. Gonzalez / American beef producers use a multitude of production regimens, with new products constantly becoming available to producers that could ultimately produce beef that fits niche markets. Additionally, U.S. producers employ the use of two exogenous growth promotants (ExGP), anabolic implants and β-adrenergic agonists, to maximize production efficiency. This body of work examined effects of different production strategies on beef quality. In the first study, steers were fed a conventional diet or a diet containing two supplements of the Programmed Nutrition Beef Program (PN) and each diet was fed with or without ExGP. There were no adverse effects on color, but use of ExGP negatively impacted tenderness of steaks. However, the inclusion of the PN supplements decreased purge loss of loins during aging and decreased cook loss of beef steaks. The decrease in purge and cook loss may be intriguing for retailer who purchase-in and cook products as they could specify a demand for beef from animals in this program to potentially save on product losses. Researchers have examined strategies to increase omega-3 fatty acids within beef, as omega-3 fatty acids are health beneficial. The second study examined impacts of feeding increasing levels of a docosahexaenoic acid (DHA)-rich microalgae to heifers on fatty acid profiles, color stability, and palatability of the LM and color and . Feeding increasing levels of microalgae meal quadratically increased total omega-3 PUFA, with increases in DHA content up to 850% and eicosapentaenoic acid (EPA) up to 340% at the greatest feeding level. Although feeding microalgae changed fatty acid profiles to be more health beneficial, color and flavor were adversely affected. At the end of display, steaks from heifers fed the greatest amount of microalgae had reduced a* (redness) values and increases in surface metmyoglobin (discoloration) formation. Panelists detected more off-flavors as the level of microalgae meal increased in the diet. Poor color stability and increases in off-flavors were due to increased oxidation products in these steaks, but problems could be mitigated by inclusion of antioxidants in the diet. The third study presented examined effects of feeding antioxidants to steers fed microalgae meal on color and palatability of Longissimus lumborum steaks. Steers were fed vitamin E at a level over their nutritional need and a selenium-yeast product in addition to feeding microalgae. Again, feeding microalgae without antioxidants in the diet negatively impacted color during display, but feeding antioxidants significantly improved the color stability. There were no off-flavor differences between steaks from steers fed the diet containing only microalgae and diet containing microalgae with antioxidants. Increasing the antioxidant content of the finishing diet when microalgae was fed is feasible way to increase the color stability of steaks and decrease off-flavors of Longissimus lumborum steaks.

The colour vision of adult citrus psylla, Trioza erytreae, was investigated in the laboratory using the behavioural parameters: alightment and walking. Light green flushing leaves (under which the nymphs develop) were significantly preferred, visually, to dark green mature leaves for alightment. Diffuse reflectance spectroscopy showed (when expressed in the parameters of human colour vision) that flush has a very slightly longer dominant wavelength, and roughly double the reflectance and purity. Alightrnent frequency correlated almost equally well with "purity" (as noted by Moericke, 1952 et seq., in "yellow-sensitive" aphids) as with the aphidological colour parameter "long/short ratio" developed by Kennedy et al. (1961). Elucidation of the mechanism underlying the citrus psylla's alightment colour preference was initially attempted with a printed spectrum and several paint series of measured spectral characteristics. It was clear that T.erytreae belongs to the "yellow-sensitive" group of Homoptera, but it was impossible to distinguish which pararneter(s) of colour the psyllids were responding to. Phototactic (walking) response to the individual parameters of colour was therefore measured using a monochromator. The phototactic action spectrum (against wavelength) was tri-modal, with peaks in the yellow-green (YG), blue (B), and ultra= violet (UV). Rate of phototaxis was not influenced by bandwidth (roughly equivalent to purity), but was proportional to intensity (roughly equivalent to reflectance). To investigate the influence of the above three wavelength regions on alightment, use was made of a very simple flight chamber incorporating a target of coloured light. Yellow-green and UV light both independently stimulated alightment . Their effect was additive. Different thresholds indicated distinct YG and UV receptor systems. Blue light alone did not stimulate alightment, and was strongly alightment-inhibitory in combination both with YG and with UV light. On the basis of the above physiological/behavioural findings, a new alightment formula was drawn up for describing the hamopteran's apparent manner of alightment determining integration of surface reflectance. The flush preference and alightment distributions on the series of artificial surfaces were found to correlate slightly more accurately, on average, as well as more consistently, with the new formula than with previously-available colour parameters. These findings are placed in perspective to the literature, and their possible economic relevance is discussed.

Most digital cameras capture images through Color Filter Arrays (CFA), and reconstruct the full color image from the CFA image. Each CFA pixel only captures one primary color component at each pixel location; the other primary components will be estimated using information from neighboring pixels. During the demosaicking algorithm, the unknown color components will be estimated at each pixel location. Most of the demosaicking algorithms use the RGB Bayer CFA pattern with Red, Green and Blue filters. Some other CFAs contain four color filters. The additional filter is a panchromatic/white filter, and it usually receives the full light spectrum. In this research, we studied and compared different four channel CFAs with panchromatic/white filter, and compared them with three channel CFAs. An appropriate demosaicking algorithm has been developed for each CFA. The most well-known three-channel CFA is Bayer. The Fujifilm X-Trans pattern has been studied in this work as another three-channel CFA with a different structure. Three different four-channel CFAs have been discussed in this research: RGBW-Kodak, RGBW-Bayer and RGBW- $5 \times 5$. The structure and the number of filters for each color are different for these CFAs. Since the Least-Square Luma-Chroma Demultiplexing method is a state of the art demosaicking method for the Bayer CFA, we designed the Least-Square method for RGBW CFAs. The effect of noise on different CFA patterns will be discussed for four channel CFAs. The Kodak database has been used to evaluate our non-adaptive and adaptive demosaicking methods as well as the optimized algorithms with the least square method. The captured values of white (panchromatic/clear) filters in RGBW CFAs have been estimated using red, green and blue filter values. Sets of optimized coefficients have been proposed to estimate the white filter values accurately. The results have been validated using the actual white values of a hyperspectral image dataset. A new denoising-demosaicking method for RGBW-Bayer CFA has been presented in this research. The algorithm has been tested on the Kodak dataset using the estimated value of white filters and a hyperspectral image dataset using the actual value of white filters, and the results have been compared. The results in both cases have been compared with the previous works on RGB-Bayer CFA, and it shows that the proposed algorithm using RGBW-Bayer CFA is working better than RGB-Bayer CFA in presence of noise.