Face detection is a preprocessing step for face recognition algorithms. It is the localization of face/faces in an image or image sequence. Once the face(s) are localized, other computer vision algorithms such as face recognition, image compression, camera auto focusing etc are applied. Because of the multiple usage areas, there are many research efforts in face processing. Face detection is a challenging computer vision problem because of lighting conditions, a high degree of variability in size, shape, background, color, etc. To build fully automated systems, robust and efficient face detection algorithms are required. Numerous techniques have been developed to detect faces in a single image; in this project we have used a classification-based face detection method using Gabor filter features. We have designed five frequencies corresponding to eight orientations channels for extracting facial features from local images. The feature vector based on Gabor filter is used as the input of the face/non-face classifier, which is a Support Vector Machine (SVM) on a reduced feature subspace extracted by using principal component analysis (PCA). Experimental results show promising performance especially on single face images where 78% accuracy is achieved with 0 false acceptances.

The aim of this essay is to investigate Face Theory, from a gender perspective, in the 19th century’s novel Pride and Prejudice by Jane Austen with the help of Speech Act Theory including direct Speech and indirect Speech. The special focuses of this investigation are if Elizabeth has a stereotypical use of FTAs strategies for different genders.

The present thesis investigates whether the emotional background (context) in which a neutral face is viewed changes one’s memory for that face. In Experiment 1, neutral faces were overlaid centrally onto emotional (positive or negative) or neutral background scenes, and recognition memory for faces was assessed. Memory for faces initially encoded in negative contexts was boosted relative to memory for faces initially encoded in neutral contexts. Further investigation was necessary to reveal the mechanism behind the influence that emotional context had on memory for faces. In Experiments 2 and 3 the spotlight theory of attention was tested to examine whether visual attention was mediating the memory effect. The spotlight theory of attention postulates that positive affective states broaden one’s scope of attention, while negative affective states narrow one’s scope of attention (Easterbrook, 1959; Derryberry & Tucker, 1994). According to this theory, the negative contexts may have narrowed attentional scope and therefore led to a richer processing of the face which happened to be presented centrally in Experiment 1, leading to boosted recognition of these faces. To test whether the varying emotional contexts did indeed shift attentional scope, Experiment 2 was designed in which neutral faces were presented once again in positive, negative or neutral contexts, however location of face presentation was peripheral rather than central. Results revealed a loss of the memory boost, for faces paired with negative contexts, reported in Experiment 1. Experiment 3 was designed to test the spotlight theory of attention using an intermixed design in which faces were presented either centrally or peripherally, randomly across trials, in emotional and neutral background scenes. In this experiment, faces were better remembered when they were viewed peripherally in positive, relative to neutral, contexts at time of study. Experiment 4 was designed to assess the validity of the spotlight theory in accounting for how emotional scenes change visual attention, by examining how performance on a flanker task differed when emotionally positive or negative scenes were presented centrally. Results suggest that positive scenes broaden the spotlight of attention, relative to negatives ones. In summary, emotional contexts lead to a boost in memory for faces paired with negative information, and this effect may be due to shifts in attention varied by the valence of the context.

The accomplishment of the γ-alkylation reaction from β-keto esters of tropinone and the enantioselective aziridine formation from nortropinone is first reported. This opened two new paths to develop tropinone enolate chemistry. One is indirect α-alkylation of tropinone, another is the nucleophilic attack from α-C enolate to the nitrogen atom.<p>Seven interesting chiral amines have been synthesized and applied into the enolate chemistry of two interesting precursors of synthesis of natural products: 1,4- cyclohexanedione monoethylene ketal and tropinone.<p>The aldol reaction between the lithium enolate of 1,4-cyclohexanedione monoethylene ketal and benzaldehyde demonstrated the high diastereoselectivity (up to 98% de) and the moderate to high enantioselectivity (up to 75% ee) induced by those chiral lithium amides. On the other hand, high diastereoselectivity (up to 100% de) and the low enantioselectivity were obtained from the aldol reaction of tropinone enolate with benzaldehyde differentiated by chiral lithium amides with extra electron donor atoms.<p>An analysis method to determine enantioselectivity from racemic α-hydroxytropinone was developed. That will, no doubt, benefit the further enantioselective α-hydroxylation reaction of tropinone.

Rotavirus NSP4, the first described viral enterotoxin, localizes to the plasma membrane of infected cells, possibly through interaction with caveolin-1. A direct interaction between NSP4 and caveolin-1, the structural protein of caveolae, was shown by yeast two-hybrid, peptide binding, and FRET analyses. To dissect the precise NSP4 binding domain to caveolin-1, mutants were prepared by altering either the charged or hydrophobic face of the NSP4 C-terminal amphipathic alpha-helix and examined for binding to caveolin-1. Replacing six charged residues with alanine (FLNSP4Ala) disrupted the charged face, while the hydrophobic face was disrupted by replacing selected hydrophobic residues with charged amino acids (aa) (FLNSP4HydroMut). In yeast two-hybrid and peptide binding assays, FLNSP4Ala retained its binding capacity, whereas FLNSP4HydroMut failed to bind caveolin-1. Mutants were generated with an Nterminal truncated clone (NSP446-175), which removed the hydrophobic domains and aided in yeast-two hybrid assays. These mutants exhibited the same binding pattern as FLNSP4 confirming that the N-terminus of NSP4 lacks the caveolin-1 binding site and NSP446-175 is sufficient for binding. Seven additional mutants were prepared from NSP4HydroMut in which individually charged residues were reverted to the original hydrophobic aa or were replaced with alanine. Analyses of the interaction of these revertants with caveolin-1 localized the NSP4 binding domain to one critical hydrophobic aa (L116) and one or two additional aa (I113, L127, and/or L134) on the hydrophobic face. Those mutants that bound caveolin-1 bound both the N- and C-terminal caveolin-1 peptides, but lacked binding to a centrally located peptide. These data suggest conformational and hydrophobic constraints play a role in the NSP4-caveolin-1 association. The mutant NSP4 molecules also were evaluated for transport to the plasma membrane. Mammalian cells were transfected with FLNSP4, FLNSP41-175Ala, and NSP41-175HydroMut plasmid DNA, surface biotinylated, and examined by IFA or Western blot for NSP4 expression. Epifluorescence revealed FLNSP4 and FLNSP4Ala were exposed on the cell surface in the absence of other viral proteins, whereas NSP4HydroMut remained intracellular. Further, NSP4-transfected cells displayed an intracellular association of with caveolin-1 or the caveolin-1 chaperone complex proteins. These data indicate NSP4 interacts with caveolin-1 in the absence of other viral proteins.

Matrix acidizing is used in carbonate formations to create wormholes that connect the formation to the wellbore. Hydrochloric acid, organic acids, or mixtures of these acids are typically used in matrix acidizing treatments of carbonate reservoirs. However, the use of these acids in deep wells has some major drawbacks including high and uncontrolled reaction rate and corrosion to well tubulars, especially those made of chrome-based tubulars (Cr-13 and duplex steel), and these problems become severe at high temperatures. Hydrochloric acid (HCl) and its based fluids have a major drawback in stimulating shallow (low fracture gradient) formations as they may cause face dissolution (formation surface washout) if injected at low rates. The objective of stimulation of sandstone reservoirs is to remove the damage caused to the production zone during drilling or completion operations. Many problems may occur during sandstone acidizing with Hydrochloric/Hydrofluoric acids (HCl/HF) mud acid. Among those problems: decomposition of clays in HCl acids, precipitation of fluosilicates, the presence of carbonate can cause the precipitation of calcium fluorides, silica-gel filming, colloidal silica-gel precipitation, and mixing between various stages of the treatment. To overcome problems associated with strong acids, chelating agents were introduced and used in the field. However, major concerns with most of these chemicals are their limited dissolving power and negative environmental impact. Glutamic acid diacetic acid (GLDA) a newly developed environmentally friendly chelate was examined as stand-alone stimulation fluid in deep oil and gas wells. In this study we used GLDA to stimulate carbonate cores (calcite and dolomite). GLDA was also used to stimulate and remove the damage from different sandstone cores containing different compositions of clay minerals. Carbonate cores (calcite and dolomite) of 6 and 20 in. length and 1.5 in. diameter were used in the coreflood experiments. Coreflood experiments were run at temperatures ranging from 180 to 300oF. Ethylene diamine tetra acetic acid (EDTA), hydroxyl ethylethylene diaminetriacetic acid (HEDTA), and GLDA were used to stimulate and remove the damage from different sandstone cores at high temperatures. X-ray Computed Topography (CT) scans were used to determine the effectiveness of these fluids in stimulation calcite and dolomite cores and removing the damage from sandstone cores. The sandstone cores used in this study contain from 1 to 18 wt percent illite (swellable and migratable clay mineral). GLDA was found to be highly effective in creating wormholes over a wide range of pH (1.7-13) in calcite cores. Increasing temperature enhanced the reaction rate, more calcite was dissolved, and larger wormholes were formed for different pH with smaller volumes of GLDA solutions. GLDA has a prolonged activity and leads to a decreased surface spending resulting in face dissolution and therefore acts deeper in the formation. In addition, GLDA was very effective in creating wormholes in the dolomite core as it is a good chelate for magnesium. Coreflood experiments showed that at high pH values (pH =11) GLDA, HEDTA, and EDTA were almost the same in increasing the permeability of both Berea and Bandera sandstone cores. GLDA, HEDTA, and EDTA were compatible with Bandera sandstone cores which contains 10 wt percent Illite. The weight loss from the core was highest in case of HEDTA and lowest in case of GLDA at pH 11. At low pH values (pH =4) 0.6M GLDA performed better than 0.6M HEDTA in the coreflood experiments. The permeability ratio (final/initial) for Bandera sandstone cores was 2 in the case of GLDA and 1.2 in the case of HEDTA at pH of 4 and 300oF. At high pH HEDTA was the best chelating agent to stimulate different sandstone cores, and at low pH GLDA was the best one. For Berea sandstone cores EDTA at high pH of 11 was the best in increasing the permeability of the core at 300oF. The low pH GLDA based fluid has been especially designed for high temperature oil well stimulation in carbonate and sandstone rock. Extensive studies have proved that GLDA effectively created wormholes in carbonate cores, is gentle to most types of casing including Cr-based tubular, has a high thermal stability and gives no unwanted interactions with carbonate or sandstone formations. These unique properties ensure that it can be safely used under extreme conditions for which the current technologies do not give optimal results. Furthermore, this stimulation fluid contributes to a sustainable future as it based on readily biodegradable GLDA that is made from natural and renewable raw material.

Thèse doctorat : Génie Mécanique : Villeurbanne, INSA : 2004. / Titre provenant de l'écran-titre. Bibliogr. p. 229-240.

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2003. / Thèse : 03NAN11036. Titre provenant de l'écran-titre.

Thesis (Ph. D.)--University of California, San Diego, 2002. / Vita. Includes bibliographical references (leaves 158-169).

Thesis (M.F.A.)--University of Central Florida, 2009. / Adviser: Carla Poindexter. Includes bibliographical references (p. 31).