Let s denote a compact convex object in IR. The f-width of s is the perpendicular distance between two distinct parallel lines of support of s with direction f . A set of disjoint convex compact objects in IR is of equal f -width if there exists a direction f such that every pair of objects have equal f -width. A visibility matching, for a set of equal f -width objects is a matching using non-c...

It was shown recently that in the segment endpoint visibility graph Vis(S) of any set S of n disjoint line segments in the plane, there is an alternating path of length (log n), and this bound best possible apart from a constant factor. This talk focuses on the variant of the problem where S is a set of n disjoint axis-parallel line segments, and shows that the length of a longest alternating p...

In this paper we present a very simple proof of the following result due to Abello et al [5], concerning the visibility graphs of simple polygons. The result says that the visibility graph of any simple nondegenerate polygon is isomorphic to the visibility graph of some simple staircase polygon. As a result of the above proof we also give an O(n log n) time algorithm for the following problem: ...

Adverse weather conditions, particularly those with low visibility, are critical to the driving tasks. However, the direct relationship between visibility distances and traffic flow/roadway safety is uncertain due to the limitation of visibility data availability. The recent growth of deployment of Road Weather Information Systems (RWIS) makes segment-specific visibility information available w...

We present a visibility method that takes advantage of the graphics hardware to give fast answers to visibility queries. Our visibility method is designed to solve two types of visibility queries: point-based visibility queries, where several visibility queries share the same origin, and planebased visibility queries, where several visibility queries have their origins on the same plane. Both o...

Fitness landscapes are central in analyzing evolution, in particular for drug resistance mutations for bacteria and virus. We show that the fitness landscapes associated with antibiotic resistance are not compatible with any of the classical models; additive, uncorrelated and block fitness landscapes. The NK model is also discussed. It is frequently stated that virtually nothing is known about ...