In order to provide a rigorous and sound foundation for formal reasoning about Web services, algebraic modeling is one of the important techniques used as is witnessed from the Web service literature. However, the algebraic modeling approach for Web services (Web service algebra) is still in its infancy. To further facilitate the algebraic modeling of Web services, in this paper, we propose a c...

A survey of two approaches for stabilizing the hierarchical basis (HB) multilevel preconditioners, both additive and multiplicative, is presented. The first approach is based on the algebraic extension of the two-level methods, exploiting recursive calls to coarser discretization levels. These recursive calls can be viewed as inner iterations (at a given discretization level), exploiting the al...

We present an approach for inferring rich invariants involving user-defined recursive functions over numerical and algebraic data types. In our approach, the developer provides the desired shape of the invariant using a set of templates. The templates are quantifier-free affine predicates with unknown coefficients. We also provide an enumeration based strategy for automatically inferring some o...

drought is random and nonlinear phenomenon and using linear stochastic models, nonlinear artificial neural network and hybrid models is advantaged for drought forecasting. this paper presents the performances of autoregressive integrated moving average (arima), direct multi-step neural network (dmsnn), recursive multi-step neural network (rmsnn), hybrid stochastic neural network of directive ap...

We propose an algebraic approach to block diagram construction as an alternative to the classical graph approach inspired by dataflow models. This block diagram algebra is based on three binary operations : sequential, parallel and recursive constructions. These operations can be seen as high level connection schemes that set several connections at once in order to combine two block diagrams to...

We propose an algebraic approach to block diagram construction as an alternative to the classical graph approach inspired by dataflow models. The proposed algebra is based on three binary operations of construction : sequential, parallel and recursive constructions. These operations can be seen as high level connection schemes that set several connections at once in order to combine two block d...

Khoussainov, B. Recursive “nary algebras and trees, Annals of Pure and Applied Logic 67 (1994) 213-268. A unary algebra is an algebraic system d = (A,f,, ,L). wheref,, . ,fm are unary operations on A and n EW. In the paper we develop the theory ofeffective “nary algebras. We investigate well-known questions of constructive (recursive) model theory with respect to the class of unary algebras. In...

We design a grid based multilevel incomplete LU preconditioner (GILUM) for solving general sparse matrices. This preconditioner combines a high accuracy ILU factorization with an algebraic multilevel recursive reduction. The GILUM precondi-tioner is a compliment to the domain based multilevel block ILUT preconditioner. A major diierence between these two preconditioners is the way that the coar...

Through the following, we establish the conditions which allow us to express recursive sequences of real numbers, enumerated through the recurrence relation an+1 = Aan + Ban−1, by means of algebraic equations in two variables of degree n ∈ N . We do this, as far as we know, like it has never been formalized before. I’d like to precise that the work was develop without the support of any well-kn...