We present a phase shift datuming and migration algorithm for the data acquired on a nonnat surface. First of all, we formulate the exploding reeector modeling scheme for a nonnat recording surface. Then, the migration scheme is found as the conjugate operator of the modeling operator. In order to get the correct migration and datuming operators, the forward modeling must be physically reasonab...

The purpose of this paper is to introduce the concept of L-fuzzybilinear operators. We obtain a decomposition theorem for L-fuzzy bilinearoperators and then prove that a L-fuzzy bilinear operator is the same as apowerset operator for the variable-basis introduced by S.E.Rodabaugh (1991).Finally we discuss the continuity of L-fuzzy bilinear operators.

We prove the decidability for a class of languages which extend BST and NP-completeness subclass them. The extended with unordered cartesian product, ordered product powerset fall in this last subclass.

Enumerating all solutions of a relational algebra equation is a natural and powerful operation which, when added as a query language primitive to the nested relational algebra, yields a query language for nested relational databases, equivalent to the well-known powerset algebra. We study sparse equations, which are equations with at most polynomially many solutions. We look at their complexity...

The present paper proposes a fast numerical method for the linear Volterra integral equations withregular and weakly singular kernels having smooth solutions. This method is based on the approx-imation of the kernel, to simplify the integral operator and then discretization of the simpliedoperator using a forward dierence formula. To analyze and verify the accuracy of the method, weexamine samp...

We study a composition operation on monads, equivalently presented as large equational theories. Specifically, we discuss the existence of tensors, which are combinations of theories that impose mutual commutation of the operations from the component theories. As such, they extend the sum of two theories, which is just their unrestrained combination. Tensors of theories arise in several context...

Abstrac t -The relational model is extended to include nested structures. This extension is formalised using the distinction between a tuple scheme and a relation scheme. The algebra and calculus languages are defined for this model. It is shown that the restricted powerset is a derived operation in the algebra and the full powerset is expressible by a safe forraula in the calculus. Since the f...