Presented in this paper is an algorithm to compute a Euclidean Voronoi diagram for circles contained in a large circle. The radii of circles are not necessarily equal and no circle inside the large circle wholly contains another circle. The proposed algorithm uses the ordinary point Voronoi diagram for the centers of inner circles as a seed. Then, we apply a series of edge-flip operations to th...

A graph is claw-free if no vertex has three pairwise nonadjacent neighbours. At first sight, there seem to be a great variety of types of claw-free graphs. For instance, there are line graphs, the graph of the icosahedron, complements of triangle-free graphs, and the Schläfli graph (an amazingly highly-symmetric graph with 27 vertices), and more; for instance, if we arrange vertices in a circle...

For i = 1, . . . . n let C(x;, r,) be a circle in the plane with centre .x i and radius r; . A repeated distance graph is a directed graph whose vertices are the centres and where (xi, x;) is a directed edge whenever x; lies on the circle with centre x, . Special cases are the nearest neighbour graph, when ri is the minimum distance between x, and any other centre, and the furthest neighbour gr...

Let M be a symplectic 4–manifold admitting a free circle action. In this paper we show that, modulo suitable subgroup separability assumptions, the orbit space N admits a fibration over the circle. The separability assumptions are known to hold in several cases: in particular, this result covers the case where N has vanishing Thurston norm, or is a graph manifold. Furthermore, combining this re...

An experiment was conducted in nine 200-m2 earthen ponds at the Asian Institute of Technology (AIT), Thailand from 17 July 2003 to 3 March 2004 (230 days). The objectives of the study were to assess the feasibility of co-culture of lotus and hybrid catfish in intensively fed ponds, to assess nutrient recovery from feed waste by lotus plants, to assess pond mud characteristics after lotus-fish c...

Voronoi diagrams are among the most important data structures in geometric modeling. Among many efficient algorithms for computing 2D Voronoi diagrams, Fortune’s sweepline algorithm (Fortune, 1986 [5]) is popular due to its elegance and simplicity. Dehne and Klein (1987) [8] extended sweepline to sweepcircle and suggested computing a type of transformed Voronoi diagram, which is parallel in nat...

In this paper an automatic segmentation method for accurate pupil boundary detection for iris recognition purpose using graph cuts is presented. Most iris segmentation algorithms used for iris recognition consider the pupil as a circular area and fit a circle to its boundary. Considering the pupil to be a circle is a method which is sensitive to the imaging condition because in the case of off ...

We describe a cell-free system that promotes TnICl transposition and transposon circle formation, a related intramolecular event. TnIO circle formation in vitro has been characterized in detail, and is shown to require a supercoiled substrate and to proceed in the absence of ATP. The reaction requires TnIO transposase protein, and either of two E. coli proteins, integration host factor (IHF) an...