We perform a comprehensive theoretical and experimental analysis of the use of all-diierent constraints. We prove that generalized arc-consistency on such constraints lies between neighborhood inverse consistency and, under a simple restriction, path inverse consistency on the binary representation of the problem. By generalizing the arguments of Kondrak and van Beek, we prove that a search alg...

Linear stability analysis of the three dimensional plane wake flow is performed using a mapped finite di?erence scheme in a domain which is doubly infinite in the cross–stream direction of wake flow. The physical domain in cross–stream direction is mapped to the computational domain using a cotangent mapping of the form y = ?cot(??). The Squire transformation [2], proposed by Squire, is also us...

We give several eecient transformations for manipulating the statistical diierence (variation distance) between a pair of probability distributions. The eeects achieved include increasing the statistical diierence, decreasing the statistical diierence, \polarizing" the statistical relationship, and \reversing" the statistical relationship. We also show that a boolean formula whose atoms are sta...

We sketch a BDD-like structure for representing unions of simple convex polyhedra, describing the legal values of a set of clocks given bounds on the values of clocks and clock di erences.

A system of diierence constraints consists of a set of inequalities of the form x i ? x j b i;j. Such systems occur in many applications, e.g., temporal reasoning. The best known algorithm to determine if a system of diierence constraints is feasible (i.e., if it has a solution) and to compute a solution if the system is feasible runs in (mn) time, where n is the number of variables and m is th...

In this paper, we present Clock Diierence Diagrams, a new BDD-like data-structure for eeective representation and manipulation of certain non-convex subsets of the Euclidean space, notably those encountered in veriication of timed automata. It is shown that all set-theoretic operations including inclusion checking may be carried out eeciently on Clock Diierence Diagrams. Other central operation...

we have developed a three level implicit method for solution of the helmholtz equation. using the cubic spline in space and nite dierence in time directions. the approach has been modi ed to drive numerov type nite dierence method. the method yield the tri- diagonal linear system of algebraic equations which can be solved by using a tri-diagonal solver. stability and error estimation of the...

On q-Di®erence Equations Moemen H. Abu-Risha Department of Mathematics Cairo University, Eygpt E-mail: [email protected] We give an investigation of some properties of solutions of linear q¡di®erence equations de ̄ned on an interval [a;1): The cases a = 0 and a > 0 are essentially di®erent. The study of the latter case is necessary for the derivation of asymptotic formulae and oscil...

The Newtonian divided-di¤erence operators generate the nil-Coxeter algebra and semigroup. A bijective correspondence between the nil-Coxeter semigroup and the symmetric group is used to provide braid-like diagrams for the former, and corresponding Reidemeister-type moves for the relations. Conditions are given for similar relations to hold in a skew group ring. Interesting extensions of the nil...

In this paper an exact model for a basic rst order -modulator is derived by means of a di erence equation. Furthermore, the second order di erence equation describing a second order -modulator is given. In addition, the conditions under which by using the exact rst order model this second order di erence equation is getting a simpler form is given too.