Hydrodynamic performance of a marine vessel mainly depends on the frictional and pressure resistance. Pressure drag reduction could be achieved by improving the shape of the vessels with implementation of modern hull forms. Hull forms optimization techniques could also be used for this purpose. Other techniques are needed to deal with the viscous portion of the total resistance, which is mainly...

A linear-time algorithm that computes the envelope of the offset of a monotone chain is presented. The scallop hull, an extended notion of the convex hull, of the monotone chain is first computed by using an approach similar to that of the convexhull construction algorithm. The offset of the scallop hull, which yields the desired envelope, can then be computed in linear time from the scallop hu...

If X is a vector space and E is a subset of X, the convex hull of E is defined to be the intersection of all convex sets containing E, and is denoted by co(E). One checks that the convex hull of E is equal to the set of all finite convex combinations of elements of E. If X is a topological vector space, the closed convex hull of E is the intersection of all closed convex sets containing E, and ...

We establish pointwise a priori estimates for solutions in D (R) of equations of type−∆pu = f (x, u), where p ∈ (1, n), ∆p := div ( |∇u|∇u ) is the p–Laplace operator, and f is a Caratheodory function with critical Sobolev growth. In the case of positive solutions, our estimates allow us to extend previous radial symmetry results. In particular, by combining our results and a result of Damascel...

This article describes a 3D CFD (computational fluid dynamics) simulation implementation of the stepped planning hull in calm water. The turbulent free surface flow around the stepped planing hull is computed with a RANSE method, using the solver ANSYS-CFX. The turbulence model used is standard k–ε. In order to simulate the disturbed free surface, VOF model is implemented. The CFD model has bee...

A new algorithm for the determination of the relative convex hull in the plane of a simple polygon A with respect to another simple polygon B which contains A, is proposed. The relative convex hull is also known as geodesic convex hull, and the problem of its determination in the plane is equivalent to find the shortest curve among all Jordan curves lying in the difference set of B and A and en...

Of late, researchers appear to be intrigued with the question; Given a set of points, what is the region occupied by them? The answer appears to be neither straight forward nor unique. Convex hull, which gives a convex enclosure of the given set, concave hull, which generates nonconvex polygons and other variants such as α-hull, poly hull, r-shape and s-shape etc. have been proposed. In this pa...

Volumetric visual hulls have become very popular in many computer vision applications including human body pose estimation and virtualized reality. In these applications, the visual hull is used to approximate the 3D geometry of an object. Existing volumetric visual hull construction techniques, however, produce a 3-color volume data that merely serves as a bounding volume. In other words it la...