T. A. Mitchell

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This paper presents a model based approach to human body tracking in which the 2D silhouette of a moving human and the corresponding 3D skeletal structure are encapsulated within a non-linear Point Distribution Model. This statistical model allows a direct mapping to be achieved between the external boundary of a human and the anatomical position. It is(More)
This paper presents a surface segmentation method which uses a simulated inflating balloon model to segment surface structure from volumetric data using a triangular mesh. The model employs simulated surface tension and an inflationary force to grow from within an object and find its boundary. Mechanisms are described which allow both evenly spaced and(More)
Mixed acetals and organotrifluoroborates undergo BF(3)·OEt(2)-promoted cross-couplings to give dialkyl ethers under simple, mild conditions. A survey of reaction partners identified a hydroxamate leaving group that improves the regioselectivity and product yield in the BF(3)·OEt(2)-promoted coupling reaction of mixed acetals and potassium alkynyl-,(More)
The formation of ethers by C-O bond formation under harsh basic or acidic conditions is an entrenched synthetic disconnection in organic chemistry. We report a strategic alternative that involves the BF(3).OEt(2)-promoted coupling of stable, easily prepared acetals with widely available potassium aryl-, alkenyl-, and alkynyltrifluoroborates. This fast,(More)
First-principles periodic slab density-functional theory (DFT) calculations with a plane-wave basis are used to predict the properties of S, Pt, and Hf adsorption on NiAl(110). Stable adsorption sites are identified, and adsorbate binding energies and structures are predicted. We find that while S adsorbs in a threefold site, the metals prefer to adsorb in(More)
This paper presents a model based approach to human body tracking in which the 2D silhouette of a moving human and the corresponding 3D skeletal structure are encapsulated within a non-linear point distribution model. This statistical model allows a direct mapping to be achieved between the external boundary of a human and the anatomical position. It is(More)
Unique reactivity of anti- and syn-acetoxypyranones was observed in oxidopyrylium-alkene [5 + 2] cycloadditions. The subtle interplay between the corresponding acetoxypyranone conformation and steric bulk of tertiary amine bases causes syn-acetoxypyranones to undergo [5 + 2] cycloaddition appreciably faster than anti-acetoxypyranones. Additionally, the(More)
A full account of studies leading to the development of a cascade sequence that generates as many as two C-C bonds, one C-O bond, and three new stereocenters providing substituted tetrahydrofurans (THFs) from simple gamma-ketoaldehydes and thiopyridyl ketene acetals is described. The process involves a tandem Mukaiyama aldol-lactonization (TMAL) and(More)