by Leung Ming-yuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1982 / Bibliography: leaves 174-177

Typescript (photocopy). / Digitized by Kansas Correctional Industries

The following document presents my dissertation composition. The work is written for eight performers, including flute, clarinet, saxophone, French horn, percussion, violin, viola, and Double Bass. The duration of the piece is approximately sixteen minutes, in a single movement. This composition explores forms of discontinuity within continuous textures, and includes particular theatrical and staging elements.

Students who are blind or have low-vision (BLV) do not have the same access to graphical curricular content as their sighted peers. This significantly affects their education, particularly in STEM subjects. Introduction of interactive tactile graphics is one of the only ways for BLV students to access graphical content, and is uniquely suited to teaching drawing skills. The goal of this engineering design project was to expand the capacity of printing technology that produces interactive raised-line graphics by creating a system to print textures that meet specific criteria for usefulness. The addition of textures to tactile graphics is essential for the graphics to be unambiguous and to communicate information about spaces and regions. Maps, geometric figures and graphs are prime examples. The system developed in this project for printing tactile textures was designed as an enhancement of an existing beta prototype printer for interactive tactile graphics co-developed at UVM and E.A.S.Y. LLC. Preliminary experimentation indicated that varying the size of the drawing stylus tip would afford the greatest range of printed textures. Based on this finding, the Texture Creation System (TCS) was designed with this new functionality. This thesis describes the process by which the categories of possible designs were refined and how the TCS - based on a system of interchangeable self-locking tapered tips - was designed, built, revised, and tested. We developed a set of six tactile textures (the Texture Set) as examples of the capabilities of the TCS. We then designed and performed an experiment in which six BLV subjects assessed the textures based on their Distinctness, Recognizability, and Variability in Degree. In all tests that mimic real-world use, the Texture Set was found to be successful in at least 75% of trials. The design also successfully addressed constraints for speed of operation, system cost, noise volume, and compatibility with the beta printer. The design also met standards for reliability and mechanical strength. Future engineering will be required to add sensors to monitor mechanical operation. Also, larger-scale user testing of the Texture Set (and other textures) will be needed for statistical significance and to provide insight into what objective properties of the textures elicit certain subjective responses, i.e. why certain textures meet design criteria better than others.

En segmentation d’images, les informations de couleur et de texture sont très utilisées. Le premier apport de cette thèse se situe au niveau de l’utilisation conjointe de ces deux sources d’informations. Nous proposons alors une méthode de combinaison couleur/texture, adaptative et non paramétrique, qui consiste à combiner un (ou plus) gradient couleur et un (ou plus) gradient texture pour ensuite générer un gradient structurel utilisé comme image de potentiel dans l’algorithme de croissance de régions par LPE. L’originalité de notre méthode réside dans l’étude de la dispersion d’un nuage de point 3D dans l’espace, en utilisant une étude comparative des valeurs propres obtenues par une analyse des composantes principales de la matrice de covariance de ce nuage de points. L’approche de combinaison couleur/texture proposée est d’abord testée sur deux bases d’images, à savoir la base générique d’images couleur de BERKELEY et la base d’images de texture VISTEX. Cette thèse s’inscrivant dans le cadre des projets ViLoc (RFC) et CAPLOC (PREDIT), le deuxième apport de celle-ci se situe au niveau de la caractérisation de l’environnement de réception des signaux GNSS pour améliorer le calcul de la position d’un mobile en milieu urbain. Dans ce cadre, nous proposons d’exclure certains satellites (NLOS dont les signaux sont reçus par réflexion voir totalement bloqués par les obstacles environnants) dans le calcul de la position d’un mobile. Deux approches de caractérisation, basées sur le traitement d’images, sont alors proposées. La première approche consiste à appliquer la méthode de combinaison couleur/texture proposée sur deux bases d’images réelles acquises en mobilité, à l’aide d’une caméra fisheye installée sur le toit du véhicule de laboratoire, suivie d’une classification binaire permettant d’obtenir les deux classes d’intérêt « ciel » (signaux LOS) et « non ciel » (signaux NLOS). Afin de satisfaire la contrainte temps réel exigée par le projet CAPLOC, nous avons proposé une deuxième approche basée sur une simplification de l’image couplée à une classification pixellaire adaptée. Le principe d’exclusion des satellites NLOS permet d’améliorer la précision de la position estimée, mais uniquement lorsque les satellites LOS (dont les signaux sont reçus de manière direct) sont géométriquement bien distribués dans l’espace. Dans le but de prendre en compte cette connaissance relative à la distribution des satellites, et par conséquent, améliorer la précision de localisation, nous avons proposé une nouvelle stratégie pour l’estimation de position, basée sur l’exclusion des satellites NLOS (identifiés par le traitement d’images), conditionnée par l’information DOP, contenue dans les trames GPS. / Color and texture are two main information used in image segmentation. The first contribution of this thesis focuses on the joint use of color and texture information by developing a robust and non parametric method combining color and texture gradients. The proposed color/texture combination allows defining a structural gradient that is used as potential image in watershed algorithm. The originality of the proposed method consists in studying a 3D points cloud generated by color and texture descriptors, followed by an eigenvalue analysis. The color/texture combination method is firstly tested and compared with well known methods in the literature, using two databases (generic BERKELEY database of color images and the VISTEX database of texture images). The applied part of the thesis is within ViLoc project (funded by RFC regional council) and CAPLOC project (funded by PREDIT). In this framework, the second contribution of the thesis concerns the characterization of the environment of GNSS signals reception. In this part, we aim to improve estimated position of a mobile in urban environment by excluding NLOS satellites (for which the signal is masked or received after reflections on obstacles surrounding the antenna environment). For that, we propose two approaches to characterize the environment of GNSS signals reception using image processing. The first one consists in applying the proposed color/texture combination on images acquired in mobility with a fisheye camera located on the roof of a vehicle and oriented toward the sky. The segmentation step is followed by a binary classification to extract two classes « sky » (LOS signals) and « not sky » (NLOS signals). The second approach is proposed in order to satisfy the real-time constraint required by the application. This approach is based on image simplification and adaptive pixel classification. The NLOS satellites exclusion principle is interesting, in terms of improving precision of position, when the LOS satellites (for which the signals are received directly) are well geometrically distributed in space. To take into account the knowledge of satellite distribution and then increase the precision of position, we propose a new strategy of position estimation, based on the exclusion of NLOS satellites (identified by the image processing step), conditioned by DOP information, which is provided by GPS data.

<p>A problem with cold pilgered tubes for OCTG applications is that they can get anisotropic properties with regard to yield strength. One source of anisotropy is texture that is developed during the cold deformation. EBSD measurements have been made on several austenitic stainless steels with different deformations to see what influence the composition has on the texture formation. The same measurements were used to study the influence of grain size on texture formation. The conclusion was that the composition can have an impact on the texture and hence has potential to also affect the anisotropy. The differences in texture cannot be associated with a specific alloying element, but is rather a synergetic effect. It was also concluded that grain structure has no strong influence on texture formation. An evaluation of three different tool designs used for cold pilgering was made. The designs evaluated are referred to as design A, B and C. EBSD measurements showed large deviations in texture in the middle of the wall compared to close to the surface of pilgered OCTG. However, the measurements showed no large differences between the three designs and the texture could not be coupled to the anisotropy.</p>

<p>Applications relying on a high static friction include various types of fixtures, couplings, bolted joints, torsion joints, etc. The common characteristic of these applications is that they rely on the friction force to maintain the relative position of two mating surfaces. Also applications relying on high dynamic friction are common, the main example being brakes, where a low friction could be devastating.</p><p>The plateau model for the friction of brakes has been refined. By using advanced electron microscopy, it has been shown that during braking a partly amorphous friction film, comprising nanosized iron oxide agglomerates, dissipates the friction energy. The film is only about 100 nm thick. It is separated from the underlying less mobile material by a thin boundary. The actual braking power is thus localised to this very thin film, leading to remarkably high power densities. In a typical case it was estimated to 40 GW/dm3.</p><p>Squeal and vibrations are critical problems for brakes. The present work has shown that a textured disc pattern may counteract squeal efficiently. The most successful pattern has spiral shaped arms in which wear resistant ceramic particles are embedded. The different wear characteristics of treated and untreated disc surface lead to an elevation of the patterned area above the rest of the disc. In a related experiment, laser technique was used to inject the particles deeper into the disc surface, and thus prolonging the time of silence. </p><p>Textured diamond surfaces have been used to study the influence of load, repeated scratching and surface roughness on the static coefficient of friction. It was shown that these surfaces were remarkably stable at high friction levels. A maximum load limit was found above which the coefficient of friction falls. This and a number of other factors were found important for the successful design of high-friction joints.</p>

Shape from Shading, Occlusion and Texture are three important sources of depth information. We review and summarize work done on these modules.

When available, wet pack peaches are produced by repackaging sliced and/or diced canned clingstone peaches into a 5-ounce MRE pouch, followed by a thermal process. In this study, wet pack diced peaches were processed in 5-ounce pouches using canned, fresh, and frozen peaches as the raw material. Calcium chloride was added at 0.0 or 0.5% (w/w) to the pouches. The pouches were then stored at 37°C for six months or 50°C for six weeks. The peaches were evaluated for texture, drained weight, pH, brix and sensory evaluations.The canned peaches were not significantly different from wet pack peaches processed using frozen and fresh peaches for overall liking when stored at 37°C for six months. Based on the inability of panelists to differentiate between peach types for overall liking, this study suggests that producers should continue to use canned clingstone peaches as the peach source for wet pack peaches.When calcium chloride was applied to wet pack peaches before thermal processing at 0.5% w/w, a significant increase was seen in the firmness of wet pack peaches after processing. Peaches treated with calcium chloride did not lose firmness as quickly when stored at 50°C for six weeks, but showed no difference in firmness loss rates when stored at 37°C for six months. Sensory analysis of the samples stored at 37°C for six months showed an improvement in firmness scores but a drastic decline in overall acceptance due to the impact of flavor scores.viMultiple levels of calcium chloride showed increased firming effects as the percentage of calcium chloride increased, with negative effects on flavor as the percentage increased. Flavor was not significantly affected by calcium chloride at 0.125% in sensory analysis. This study concludes that to optimize flavor and firmness of wet pack peaches, calcium chloride should only be added at a level up to 0.125%(w/w) that will result in a final pH ≥3.85.

The texture of tortillas was improved by the addition of maltogenic amylase and carboxymethylcellulose (CMC) and guar gum to fresh masa from ground nixtamal (FNM) and nixtamalized corn flour (NCF) masa. Differences in the performance of additives in tortillas held under refrigeration or ambient storage were documented. For NCF tortillas, significant improvements were obtained in objective and subjective texture measurements by two treatments. Tortilla texture was improved by a treatment with a high enzyme level (170 mg/kg of maltogenic α-amylase, 0.14% CMC, 0.85% guar) as measured by objective tests and by a treatment with low enzyme level (60 mg/kg of maltogenic α-amylase, 0.43% CMC, 0.57% guar) as measured by subjective tests. The addition of maltogenic α-amylase (70 mg/kg) and CMC (0.35%) to FNM tortillas at levels similar to the low enzyme NCF treatment but with lower guar level (0.12%) improved tortilla texture. The maltogenic α-amylase softened tortillas by trimming the starch structure. This allowed the guar to interfere with amylopectin re-crystallization inside gelatinized starch granules. The CMC created a more flexible intergranular matrix that helped maintain the disrupted tortilla structure. Guar was ineffective in refrigerated tortillas, whereas, maltodextrins effectively improved refrigerated tortillas. The sequence of partial starch hydrolysis, warm holding condition, and time for guar to associate with starch and CMC was necessary to improve tortilla texture. Thus, different additives may be required for cold versus room temperature storage. Sugars increased in enzyme-treated tortillas during storage. This suggests that maltogenic α-amylase was only partially inactivated during baking of corn tortillas. Tortillas with more enzyme had lower and later pasting viscosity as measured by a Rapid Viscoanalyzer. Tortillas prepared from FNM also had lower and later pasting viscosity compared to NCF tortillas. Pasting viscosity of tortillas revealed intrinsic starch polymer characteristics and interactions. Results of this study provide commercially applicable information about desired levels for the extent of starch hydrolysis, the type and amount of gums and starches, and product microstructure to delay staling of corn tortillas.