In this paper we study the art gallery problem, which is one of the fundamental problems in computational geometry. The objective is to place a minimum number of guards inside a simple polygon so that the guards together can see the whole polygon. We say that a guard at position x sees a point y if the line segment xy is contained in the polygon. Despite an extensive study of the art gallery pr...

10 One of the earliest and most well known problems in computational geometry is 11 the so-called art gallery problem. The goal is to compute the minimum number of 12 guards needed to cover the interior of any polygon with n vertices; the guards are 13 to be placed on the vertices of the polygon. We consider the problem of guarding an 14 art gallery which is modeled as a polygon with curvilinea...

The purpose of this study was to describe structural and functional characteristics of elite Serbian basketball players and to evaluate whether players in different positional roles have different physical and physiological profiles. Five men's basketball teams participated in the study and competed in the professional First National League. Physiological measurements were taken of 60 players d...

we consider a dynamic domination problem for graphs in which an infinitesequence of attacks occur at vertices with guards and the guard at theattacked vertex is required to vacate the vertex by moving to a neighboringvertex with no guard. other guards are allowed to move at the same time, andbefore and after each attack and the resulting guard movements, the verticescontaining guards form a dom...

We describe how guards can be used to ensure that formulas in a partial logic are meaningful, and how guards and guarded formulas can be proved using classical logic. In addition to this theoretical utility, guards are useful in practice as a simple means of exposing aws in speci cations. We illustrate this use of guards with several examples in the Z speci cation language, using Z/EVES.

The problem of wireless localization asks to place and orient stations in the plane, each of which broadcasts a unique key within a fixed angular range, so that each point in the plane can determine whether it is inside or outside a given polygonal region. The primary goal is to minimize the number of stations. In this paper we establish a lower bound of ⌊2n/3⌋−1 stations for polygons in genera...

We define and study the following two-player game on a graph G. Let k ∈ N∗. A set of k guards is occupying some vertices of G while one spy is standing at some node. At each turn, first the spy may move along at most s edges, where s ∈ N∗ is his speed. Then, each guard may move along one edge. The spy and the guards may occupy same vertices. The spy has to escape the surveillance of the guards,...

We investigate a variation of the art gallery problem in which a team of mobile guards tries to track an unpredictable intruder in a simply-connected polygonal environment. In this work, we use the deployment strategy for diagonal guards originally proposed in [1]. The guards are confined to move along the diagonals of a polygon and the intruder can move freely within the environment. We define...

Inheritance Anomaly is considered as a major problem in integrating object-orientation and concurrency. The anomaly forces redefinitions of inherited methods to maintain the integrity of concurrent objects. In this paper we discuss how the use of boolean, access and path guards attached to methods solve the problem of inheritance anomaly. Synchronizationusing boolean guards have known to be fre...