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In this paper we present a new framework to approach the problem of structural shape and topology optimization. We use a level set method with an implicit moving boundary model. As a boundary optimization problem, the structural boundary description is implicitly embedded in a scalar function as its " iso-surfaces. " Such level set models are flexible in(More)
In this study, a novel approach of high speed scratching is carried out on silicon (Si) wafers at nanoscale depths of cut to investigate the fundamental mechanisms in wafering of solar cells. The scratching is conducted on a Si wafer of 150 mm diameter with an ultraprecision grinder at a speed of 8.4 to 15 m/s. Single-point diamonds of a tip radius of 174,(More)
Deformation twinning evolution from a single crystal is conducted by molecular dynamics simulations, to elucidate a twinned face-centered-cubic alloy in an experiment with hardness up to 100 times as that of single crystals, and with ductility simultaneously. Critical twinning stress of cadmium zinc telluride (CdZnTe or CZT) calculated is 1.38 GPa. All the(More)
Nanoscale solely amorphous layer is achieved in silicon (Si) wafers, using a developed diamond wheel with ceria, which is confirmed by high resolution transmission electron microscopy (HRTEM). This is different from previous reports of ultraprecision grinding, nanoindentation and nanoscratch, in which an amorphous layer at the top, followed by a crystalline(More)
Abstracf-For the advantages of non-measurement, quickness, convenience and, most especially, the capability of reconstructing an object surface from just one image, the method of SFS (Shape from Shading) has play an important role in RE (Reverse engineering), object location, pattern recognition and related fields. Recently, many scholars focus; on the(More)