A circle graph is the intersection graph of a set of chords of a circle. If a circle graph is prime for the split (or join) decomposition defined by Cunnigham, it has a unique representation as a set of intersecting chords, and we prove that this representation can be defined by monadic second-order formulas. By using the (canonical) split decomposition of a circle graph, one can define in mona...

A defensive alliance in a graph is a set $S$ of vertices with the property that every vertex in $S$ has at most one moreneighbor outside of $S$ than it has inside of $S$. A defensive alliance $S$ is called global if it forms a dominating set. The global defensive alliance number of a graph $G$ is the minimum cardinality of a global defensive alliance in $G$. In this article we study the global ...

A well known result due to Ankeny and Rivlin [1] states that if p(z) = ∑n v=0 avz v is a polynomial of degree n satisfying p(z) 6= 0 for |z| < 1 then for R ≥ 1 max |z|=R |p(z)| ≤ R n + 1 2 max |z|=1 |p(z)|. It was proposed by late Professor R.P. Boas, Jr. to obtain an inequality analogous to this inequality for polynomials having no zeros in |z| < K, K > 0. In this paper, we obtain some results...

Circle graphs are derived from the intersections of a set of chords. They have applications in VLSI design, bioinformatics, and chemistry. Some intractable problems on general graphs can be solved in polynomial time on circle graphs. As such, the study of circle graph algorithms has received attention. State-of-the-art algorithms for finding the maximum weight clique of a circle graph are very ...

Indonesia is one of the largest multicultural countries in world. This reality can be seen through diverse and extensive socio-cultural geographical conditions. study aims to investigate implementation Inside-Outside Circle (IOC) instructional model for education. research used qualitative quantitative methods. Methods data collection using observation, interviews literature study. The results ...

In this article we consider circularly symmetric incompressible viscous flow in a disk. The boundary condition is no-slip with respect to a 4 prescribed time-dependent rotation of the boundary about the center of the disk. We prove that, if the prescribed angular velocity of the boundary 5 has finite total variation, then the Navier–Stokes solutions converge strongly in L2 to the corresponding ...

Consider a family of chords i n a c ircle . is obtained by representing each chord by a vertex, two vertices being connected by an edge when the corresponding chords intersect. I n t h i s paper, we describe e f f i c i en t algorithms for finding a ma3cimwn clique and a maximum independent s e t of circle graphs. the number of vertices i n the graph. Key WO&: Circle graph, transi t ive graph, ...

This paper is concerned with the problem of designing discrete-time control systems with closed-loop eigenvalues in a prescribed region of stability. First, we obtain a state feedback matrix which assigns all the eigenvalues to zero, and then by elementary similarity operations we find a state feedback which assigns the eigenvalues inside a circle with center   and radius. This new algorithm ca...