abstract government size plays a vital role in the economic development process. therefore, in this study, the existence of a non-linear relationship between government size and economic growth was investigated using the two-sector production function developed by ram (1986). the data, covering 44 years (1961-2005), were collected from the iranian economic information center. two classification...

Perfect simulation, or coupling from the past, is an efficient technique for sampling the steady state of monotone discrete time Markov chains. Indeed, one only needs to consider two trajectories corresponding to minimal and maximal state in the system. We show here that even for non-monotone systems one only needs to compute two trajectories: an infimum and supremum envelope. Since the sequenc...

A conjecture of G. Fan and A. Raspaud asserts that every bridgeless cubic graph contains three perfect matchings with empty intersection. We suggest a possible approach to problems of this type, based on the concept of a balanced join in an embedded graph. We use this method to prove a special case of a conjecture of E. Máčajová and M. Škoviera on Fano colorings of cubic graphs.

A polytope is perfect if its shape cannot be changed without changing the action of its symmetry group on its face-lattice. There was a conjecture by which perfect 4-polytopes formed a rather limited class of Wythoffian polytopes. It was disproved in a preceding paper of the author by showing that this class is much more wide. In the present paper we go even further by giving a construction tha...

Let Pn be a set of n m points that are the vertices of a convex polygon and let Mm be the graph having as vertices all the perfect matchings in the point set Pn whose edges are straight line segments and do not cross and edges joining two perfect matchings M and M if M M a b c d a d b c for some points a b c d of Pn We prove the following results about Mm its diameter is m it is bipartite for e...

We investigate divergence-type theories describing the disipative interaction betwen a field and a fluid. We look for theories which, under equilibrium conditions, reduce to the theory of a Klein-Gordon scalar field and a perfect fluid. We show that the requirements of causality and positivity of entropy production put non-trivial constraints to the structure of the interaction terms. These the...

The complement of a graph G is denoted by G. χ(G) denotes the chromatic number and ω(G) the clique number of G. The cycles of odd length at least five are called odd holes and the complements of odd holes are called odd anti-holes. A graph G is called perfect if, for each induced subgraph G of G, χ(G) = ω(G). Classical examples of perfect graphs consist of bipartite graphs, chordal graphs and c...

The study of nonlinear properties of Boolean functions is one of the major tasks in secret-key cryptography. But the adjective "nonlinear" has several meanings: it can be related to the resistance against the famous differential attack [2] and, in this interpretation, actually refers to (almost) perfect nonlinear functions. Moreover nonlinearity is also related to the maximum magnitude of the F...

The Strong Perfect Graph Conjecture (SPGC) was certainly one of the most challenging conjectures in graph theory. During more than four decades, numerous attempts were made to solve it, by combinatorial methods, by linear algebraic methods, or by polyhedral methods. The rst of these three approaches yielded the rst (and to date only) proof of the SPGC; the other two remain promising to consider...