James Ching-Yu Yang

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Moire´patterns often appear in the image obtained from scanning an image printed on a magazine or a newspaper. The patterns do not exist in the original printing but come from alias sampling of screened halftone pictures. A strategy to design a moire´suppression scanning procedure is proposed. Fourier analysis is presented for both the screening and the(More)
Experiments are reported on the combustion of free or unsupported methanol/dodecanol mixture droplets in a reduced gravity environment. The experiments were conducted in a drop tower. The Grashof number (based on drop diameter) in the moving frame of reference was on the order of 10-5 for the period of droplet burning. Combustion of the mixture droplets was(More)
Experimental observations of the combustion of sooting fuel droplets, performed in a drop tower to create a low gravity environment, are reported. Free n-heptane droplets and suspended droplets of heptane. monochloroalkanes. and mixtures of monochloro-octane and heptane were studied. Initial droplet diameters ranged from 0.4 to I. 1 mm. The results suggest(More)
MoireH patterns are distortions on the results of scanning printed documents. However, the patterns can be utilized in document image segmentation and quality improvement. The moireH phenomenon comes from sampling periodical structures in images, such as halftone screens, color components, and text galleys which often appear in printed magazines and(More)
The main purposes of this study were to estimate the reliability of oral examinations administered to medical students during a clinical clerkship and to improve the reliability of this evaluation technique. In the first part of the study, the reliability of oral examinations as traditionally administered was estimated. The average intraclass reliability(More)
The results of an experimental study of the effect of fuel composition on burning of unsupported droplets in a reduced gravity environment are reported. The liquids studied were mixtures of heptane and hexadecane. The experiments were conducted in a drop tower which provided an experimental observation time of about 1.2 s. The experimental technique(More)
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