the length-weight relationships for three fish species from beheshtabad river, karun river drainage (western chaharmahal and bakhtiari provinces, iran) were investigated. the values of the slope parameter ( b ) in the length-weight relationship equations were determined as 2.79 for capoeta damascina , 3.10 for chondrostoma regium and 3.09 for oncorhynchus mykiss , all of which were significantl...

We examine a variant of the maximum empty square (or rectangle) problem: Find an axis-aligned square (or rectangle) that contains as many blue points as possible without containing any red points. Let n be the total number of red and blue points. We solve the bichromatic square problem in O(n log n) time and O(n) space. We also solve the bichromatic rectangle problem in O(n log n) time and O(n ...

Land, a non-renewable resource, is central to all primary production systems. The geospatial technology of Remote Sensing and GIS holds the potential for timely and cost – effective assessment of natural resources. The techniques have been used extensively in the tropics for generating valuable information about various surface features of the earth. Therefore, we have used Remote Sensing and G...

In the weighted rectangle stabbing problem we are given a grid in ]R2 consisting of columns and rows each having a positive integral weight, and a set of closed axis-parallel rectangles each having a positive integral demand. The rectangles are placed arbitrarily in the grid with the only assumption that each rectangle is intersected by at least one column and at least one row. The objective is...

The drainage networks of catchment areas burned by wildfire were analysed at several scales. The smallest scale (1–1000 m) representative of hillslopes, and the small scale (1000 m to 1 km), representative of small catchments, were characterized by the analysis of field measurements. The large scale (1–1000 km), representative of perennial stream networks, was derived from a 30-m digital elevat...

Approximate predicates can be used to reduce the number of comparisons made by expensive, complex predicates. For example, to check if a point is within a region (expensive predicate) we can first check if the point is within a bounding rectangle (approximate predicate). In general, approximate predicates may have false positive and false negative errors. In this paper we study the problem of s...

Let us consider the interval [0, 1) as a billiard table rectangle with perimeter 1 and a sequence F(m) ∈ [0, 1),m ∈ N ∪ {0}, of successive rebounds of a billiard ball against the sides of a billiard rectangle. We prove that if I is an open segment of a billiard rectangle, then the differences between the successive values of m for which the F(m) lies in I , take at most one even and at most fou...

The paper considers representations of bipartite graphs as rectangle-visibility graphs, Le., graphs whose vertices are rectangles in the plane, with adjacency detenmned by horizontal and vertical visibility.1t is shown that, for p ~ q, Kp,q has a representation with no rectangles having collinear sides if and only if p ~ 2 or p = 3 and q ~ 4. More generally, it is shown that Kp;q is a rectangle...

We consider approximation algorithms for the problem of computing an inscribed rectangle having largest area in a convex polygon on n vertices. If the order of the vertices of the polygon is given, we present a randomized algorithm that computes an inscribed rectangle with area at least (1− ) times the optimum with probability t in time O( 1 log n) for any constant t < 1. We further give a dete...

BACKGROUND AND PURPOSE Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perime...