The identification of the interfacial molecules in fluid-fluid equilibrium is a long-standing problem in the area of simulation. We here propose an alternative point of view, making use of concepts taken from the field of computational geometry, where the definition of the "shape" of a set of points is a well-known problem. In particular, we employ the alpha -shape construction which, applied t...

The size and shape of macromolecules such as proteins and nucleic acids play an important role in their functions. Prior efforts to quantify these properties have been based on various discretization or tessellation procedures involving analytical or numerical computations. In this article, we present an analytically exact method for computing the metric properties of macromolecules based on th...

Studies exploring the role of neural oscillations in cognition have revealed sustained increases in alpha-band (~8-14 Hz) power during the delay period of delayed-recognition short-term memory tasks. These increases have been proposed to reflect the inhibition, for example, of cortical areas representing task-irrelevant information, or of potentially interfering representations from previous tr...

Frequently, data in scientiic computing is in its abstract form a nite point set in space, and it is sometimes useful or required to compute what one might call the \shape" of the set. For that purpose, this paper introduces the formal notion of the family of-shapes of a nite point set in IR 3. Each shape is a well-deened polytope, derived from the Delaunay triangulation of the point set, with ...

LIDAR (Light Detection And Ranging) is an active remote sensing system, which could provide fleetly three dimensional information of earth surface with high vertical accuracy. Now the building boundary extraction and normalization is the key approach for 3D modeling of building and city mapping. In this paper, a new algorithm named Alpha Shapes is developed to extract the building boundary. Com...

Changes in the human neuromagnetic alpha rhythm were monitored during an object detection task to study the effects of visual shape processing on the parieto-occipital activity. Pictures of coherent meaningful objects, which the observers had to detect, and of disorganized meaningless non-objects were presented briefly between masks. The non-objects were systematically followed by a higher leve...

A nonuniform-shape photonic crystal taper integrated with a single-mode optical fiber and a photonic crystal waveguide for high-efficiency mode coupling is presented. The curvature of the tapering section is varied by the parameter alpha. For values of alpha set to 2 and 0.5, concave and convex tapers are obtained, respectively. Numerical calculations yield an average coupling efficiency greate...