In this paper some operations are described that transform every graph into a perfect graph by replacing nodes with sets of new nodes. The transformation is done in such a way that every stable set in the perfect graph corresponds to a stable set in the original graph. These operations yield a purely combinatorial augmentation procedure for finding a maximum weighted stable set in a graph. Star...

among others internal, regional, international, political, economic, technical, social and cultural factors are reasons that theorists introduce for beginning of integration at a region. by looking at the functions of the shanghai cooperation organization and the association of southeast asian nations (asean), we understand that there are two basic pragmatic factors, the support of the great po...

The ring of graph invariants is spanned by the basic graph invariants which calculate the number of subgraphs isomorphic to a given graph in other graphs. Sets of basic graph invariants form ensembles where each graph in the set induces the corresponding invariant calculating the number of subgraphs isomorphic to this graph in other graphs. It is well known that all other graph invariants such ...

Transnational crime, sometimes called international crime or multinational systemic crime, is more than an extension of domestic crime. In the context of globalization, transnational organized crime groups respond to market incentives and operate with cooperative relationships, which makes the multinational criminal systems become more efficient and powerful. As a result, no single country has ...

Decision power is very important in group decision making, which effects the final decision making result. When there exists uncertainty in group decision making, it is easy for an expert to express his/her preferences using fuzzy linguistic term such as ‘good’, ‘very good’. The linguistic 2-tuple representation model was selected to represent fuzzy linguistic term for its accuracy in represent...

In this paper, we propose a method for maintaining the region visible from a moving point observer inside a planar scene. In this method, we check the observer position in discrete time-stamps to detect and apply changes to the visible or illuminated region of a moving point observer q, or VP(q). We efficiently maintain a list C(q) of edges in VP(q) which are subject to change during the motion...

We review the stamp folding problem, the number of ways to fold a strip of n stamps, and the related problem of enumerating meander configurations. The study of equivalence classes of foldings and meanders under symmetries allows to characterize and enumerate folding and meander shapes. We describe symmetric foldings and meanders, and we give formulas relating folding and meander sequences. We ...