Tsz Wai Wong

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In this paper, we propose a general framework for approximating differential operator directly on point clouds and use it for geometric understanding on them. The discrete approximation of differential operator on the underlying manifold represented by point clouds is based only on local approximation using nearest neighbors, which is simple, efficient and(More)
Four patients suffering from oligospermia and infertility were found to have slightly to moderately elevated serum prolactin levels consistently. Their testicular biopsy specimens showed varying degrees of impairment of spermatogenesis ranging from hypospermatogenesis to complete absence of germ cells. The usual known causes of hyperprolactinemia, such as(More)
Surface parameterizations and registrations are important in computer graphics and imaging, where 1-1 correspondences between meshes are computed. In practice, surface maps are usually represented and stored as three-dimensional coordinates each vertex is mapped to, which often requires lots of memory. This causes inconvenience in data transmission and data(More)
In shape analysis, finding an optimal 1-1 correspondence between surfaces within a large class of admissible bijective mappings is of great importance. Such process is called surface registration. The difficulty lies in the fact that the space of all surface diffeomorphisms is a complicated functional space, making exhaustive search for the best mapping(More)
Thecal metaplasia of the adrenal was observed as an incidental autopsy finding in a 77-year-old man with acquired bilateral testicular atrophy, probably secondary to previous bilateral inguinal herniorrhaphy. The metaplastic focus was composed of interlacing bundles of spindle cells attached to the adrenal capsule, strongly resembling ovarian theca. A(More)
We develop a new algorithm to automatically register hippocampal (HP) surfaces with complete geometric matching, avoiding the need to manually label landmark features. A good registration depends on a reasonable choice of shape energy that measures the dissimilarity between surfaces. In our work, we first propose a complete shape index using the Beltrami(More)
We describe a simple and inexpensive method for determining the location of phosphoamino acids in an isolated phosphopeptide. Phosphopeptides are immobilized on arylamine membrane discs using water-soluble carbodiimide, and the immobilized peptides are subjected to manual Edman degradation. The use of a membrane disc resulted in excellent recovery (65 to(More)
We address the problem of detecting deformities on elastic surfaces. This is of great importance for shape analysis, with applications such as detecting abnormalities in biological shapes (e.g., brain structures). We propose an effective algorithm to detect abnormal deformations by generating quasi-conformal maps between the original and deformed surfaces.(More)