Abstract A topological relationship is a key factor in the spatial data processing. Aiming at problem of similarity measurement when dimension objects changes process map generalization, this paper proposes method based on global concept neighborhood graph. Firstly, all relationships that can be described by nine intersection model are abstracted, generalized, and classified, classified point/p...

If we construct isosceles polygon Pa k with (k − 1) sides of the same length over each side of regular polygon Pb n , with n sides, we get a new equilateral polygon P a,δ N with N = (k− 1)n sides of the same length and with different inner angles. Such polygon is called equilateral semi-regular polygon. This paper deals with metric properties of general semi-regular polygons Pa N , with given s...

We consider the navigation problem of a robot from a starting point S to a target point T inside an unknown rectilinear polygon. The robot knows the directions of the points S and T and it can detect the edges of the polygon through its tactile sensors. We present a competitive strategy for the robot to reach the target T . The competitive ratio of our strategy is 6 4:5dðj 1Þðjþ 2Þ þOð1Þ, where...

We extend the concept of the polygon visible from a source point S in a simple polygon by considering visibility with two types of reeection, specular and diiuse. In specular reeection a light ray reeects from an edge of the polygon according to the rule: the angle of incidence equals the angle of reeection. In diiuse reeection a light ray reeects from an edge of the polygon in all inward direc...

ABSTRACT: In this paper a new algorithm has been proposed which can fix the problem of WeilerAtherton algorithm. The problem of Weiler-Atherton algorithm lies in clipping self-intersecting polygon. Clipping self-intersecting polygon is not considered in Weiler-Atherton algorithm and hence it is also a main disadvantage of this algorithm. In our new algorithm a self-intersecting polygon has been...

In this paper we consider the k-link visibility polygon of an object inside a polygonal environment with a reflective edge called a mirror. The k-link visibility polygon of an object inside a polygon P is the set of all points in P , which are visible to some points of that object with at most k − 1 intermediate points, under the property that consecutive intermediate points are mutually visibl...

This paper presents three multivariate geostatistical algorithms for incorporating a digital elevation model into the spatial prediction of rainfall: simple kriging with varying local means; kriging with an external drift; and colocated cokriging. The techniques are illustrated using annual and monthly rainfall observations measured at 36 climatic stations in a 5000 km region of Portugal. Cross...

The mosquito Aedes albopictus, indigenous to Southeast Asia and nearby islands, has spread almost worldwide during recent decades. We confirm the invasion of this mosquito, first reported in Yamagata city in northeast Honshu, Japan in 2000. Previously, only Ae. japonicus japonicus had been collected in this place, but 2 years later, the population of Ae. albopictus had increased, so more than 8...

We consider the methods of construction simple polygons for a set S of n points and applying them for searching the minimal area polygon. In this paper we propose the approximate algorithm, which generates the simple polygonalizations of a fixed set of points and finds the minimal area polygon, in O (n) time and using O(n) memory. Keywords—simple polygon, approximate algorithm, minimal area pol...

In this paper, we introduce a modified fence fill algorithm for filling a polygon. Fence fill algorithm is a modified edge fill algorithm. As opposed to the edge fill algorithm that fills pixels starting from the polygon edge to the maximum screen coordinates, the fence fill algorithm fills pixels bounded by the polygon edge and the fence. This involves large number of calculations to find the ...