We give an algorithm that reduces the straight skeleton to the motorcycle graph in O(n log n) time for (weakly) simple polygons and O(n(log n) logm) time for a planar straight line graph with m connected components. The current fastest algorithms for computing motorcycle graphs are an O(n ) time algorithm for non-degenerate cases and O(n ) for degenerate cases. Together with our algorithm this ...

We present an (n log n) xed order algebraic decision tree lower bound for determining the existence of a line stabber for a family of n line segments in the plane. We give the same lower bound for determining the existence of a line stabber for n translates of a circle in the plane. In proving this lower bound, we show that this problem is equivalent to determining if the width of a set of poin...

We propose here algorithms to perform two new operations on an arrangement of line segments in the plane, represented by a trapezoidal map: the split of the map along a given vertical line D, and the union of two trapezoidal maps computed in two vertical slabs of the plane that are adjacent through a vertical line D. The data structure is a modiied Innuence graph, still allowing dynamic inserti...

detection of oil-water contacts (owcs) is one of the primary tasks before evaluation of reservoir’s hydrocarbon in place, determining net pay zones and suitable depths for perforation operation. this paper introduces bayesian decision making tool as an effective technique in owc detecting using wire line logs. to compare strengths of the suggested method in detecting owc with conventional one, ...

background: potency test for control of rubella vaccine is a significant factor to qualify production line and vaccination pro­gram. for this reason, who recommends to use the microtitration method by both vaccine companies and control laborato­ries. then the study was done to improve this test. methods: three rubella virus samples, including an in-house standard, a lot of vaccine and an in- pr...

We present an analysis of the integrated Hα emission line profiles for the H  region population of the spiral galaxies NGC 1530, NGC 6951 and NGC 3359. We show that ∼70% of the line profiles show two or three Gaussian components. The relations between the luminosity (log LHα) and non–thermal line width (log σnt) for the H  regions of the three galaxies are studied and compared with the rela...

Let G be a finite set of points in the plane. A line M is a (k, k)-line, if M is determined by G, and there are at least k points of G in each of the two open half-planes bounded by M . Let f(k, k) denote the maximum size of a set G in the plane, which is not contained in a line and does not determine a (k, k)-line. In this paper we improve previous results of Jaakov Kupitz (f(k, k) ≤ 3k), Noga...

In this paper we present and analyze on-line routing schemes with contant buuer size and hot-potato routing schemes for vertex-symmetric networks. In particular, we prove that for any vertex-symmetric network with n vertices, degree d, and diameter D = (log n), a randomly chosen function and any permutation can be routed in time { O(log n D), with high probability (w.h.p.), if constant size buu...

In this paper, we consider a map labeling problem to maximize the number of independent labels in the plane. We first investigate the point labeling model that each label can be placed on a given set of anchors on a horizontal line. It is known that most of the map labeling decision models on a single line (horizontal or slope line) can be easily solved. However, the label number maximization m...