The visual hull relates the shape of an object to its silhouettes. This paper develops the theory of the visual hull of piecewise smooth objects, as those used in CAD applications. We show that the surface of the visual hull can be constructed using patches of nine visual event surfaces of the aspect graph of the object. A detailed analysis allows to prune away many surfaces and patches that ar...

We prove a tight asymptotic bound of Θ(δ log(n/δ)) on the worst case computational complexity of the convex hull of the union of two convex objects of sizes summing to n requiring δ orientation tests to certify the answer. Our algorithm is deterministic, it uses portions of the convex hull of input objects to describe the final convex hull, and it takes advantage of easy instances, such as thos...

José Córdoba Centre for Systems Studies, Business School University of Hull Cottingham Road, Hull, HU6 7RX E-mail: [email protected] Telephone number: 01482-465021 Fax Number: 01482-466637

This invention applies to more accurate determination of the displacement of merchant ships built from elastic materials, which suffers from significant temporary or permanent longitudinal deflections in ship's service due to hull bending, such as hull sagging or hogging, what provokes changes of the immersed hull form, leading to inaccuracies in 10 determination of the ship's displacement, par...

An application of Fourier descriptors and convex hull for shape analysis is presented. Convex hull is used for dividing a shape into small parts. Amplitude spectrum which is invariant to scaling, translation and choosing a starting point is obtained from the Fourier descriptors (see e.g [1-3]) and used for comparison. All calculations are performed with the author's software and some algorithms...

The alkaline cooking of corn in a solution of Ca(OH)2 to produce corn-based foods is oriented to make corn proteins available, to incorporate Ca to the cooked grains, and also to remove the corn hull. This process (nixtamalization) is known in Mexico and Guatemala from prehispanic times; however, the effect of the alkaline cooking on the corn hull remains poorly documented. In this work, the ph...

Recently the invariant (copoint) pre-hull number ph(G) of a graph G that measures the nonconvexity of a convex space was introduced by Polat and Sabidussi in [18]. We introduce a similar invariant called convex pre-hull number which is a natural upper bound for the copoint pre-hull number and consider in this work both on the lexicographic product of graphs. We present exact values with respect...

We find a bound for the Goldie dimension of hereditary modules in terms of the cardinality of the generator sets of its quasi-injective hull. Several consequences are deduced. In particular, it is shown that every right hereditary module with countably generated quasi-injective hull is noetherian. Or that every right hereditary ring with finitely generated injective hull is artinian, thus answe...

This series of occasional articles provides an update on the best use of key diagnostic tests in the initial investigation of common or important clinical presentations. The series advisers are Steve Atkin, professor, head of department of academic endocrinology, diabetes, and metabolism, Hull York Medical School; and Eric Kilpatrick, honorary professor, department of clinical biochemistry, Hul...

Kelly Cleland1,*, Haoping Zhu2, Norman Goldstuck3, Linan Cheng4, and James Trussell1,5 Office of Population Research, Princeton University, 218 Wallace Hall, Princeton, NJ 08544, USA Minhang Central Hospital, Shanghai Jiaotong University, Shanghai 201100, People’s Republic of China Reproduction Research South Africa, St John’s Rd, Sea Point, Cape Town 8005, South Africa Shanghai Institute of Pl...