We show the existence of positive solutions for a class of singular elliptic systems with convection term. The approach combines sub and supersolution method with the pseudomonotone operator theory and perturbation arguments involving singular terms. 2000 Mathematics Subject Classi…cation: 35J50, 35J60, 35J75

A theory of associative deformations is developed for general complex analytic spaces. Deformation quantization and commutative deformation are particular cases of this concept. Deformation cohomology and obstruction are studied. It is proved that any compact analytic space has a formal versal associative deformation. Mathematics Subject Classi…cation (2000). 53D55, 13D10, 16S80, 81T70.

The probabilistic approach is used for constructing special layer methods to solve the Cauchy problem for semilinear parabolic equations with small parameter. In spite of the probabilistic nature these methods are nevertheless deterministic. The algorithms are tested by simulating the Burgers equation with small viscosity and the generalized KPP-equation with a small parameter. 1991 Mathematics...

We prove that the cyclic homology of a scheme with an ample line bundle coincides with the cyclic homology of its category of algebraic vector bundles. As a byproduct of the proof, we obtain a new construction of the Chern character of a perfect complex on a ringed space. 1991 Mathematics Subject Classi cation: Primary: 16E40; Secondary: 18E30, 14F05.

This paper deals with stability properties of the feasible set of linear inequality systems having a …nite number of variables and an arbitrary number of constraints. Several types of perturbations preserving consistency are considered, a¤ecting respectively, all of the data, the left-hand side data, or the right-hand side coe¢ cients. Mathematics Subject Classi…cation (2000): Primary : 49K40, ...

MIPC is a well-known intuitionistic modal logic of Prior (1957) and Bull(1966). It is shown that every normal intuitionistic modal logic L over MIPC has the nite model property whenever L is Kripke-complete and universal. Mathematics Subject Classi cation: 03B45, 03B25.

Using Lichtenbaum's complex (2), we reprove and extend a little bit some known results relating the kernel of H 3 (F;Q=Z(2)) ! H 3 (F (X);Q=Z(2)) to the torsion of CH 2 X for rational varieties X . 1991 Mathematics Subject Classi cation: Primary 14C35, secondary 19E20.

We propose and discuss distance measures to compare objects that have heterogeneous sets of characteristics, such as encountered in, for example, medical diagnosis and information retrieval. We treat both boolean-valued and (scaled) real-valued characteristics. Weighting of characteristics is accomodated. The paper is a modi ed and extended version of [1]. 1991 Mathematics Subject Classi cation...

We introduce marginal worth vectors and quasi-supermodular games on convex geometries. Furthermore, we study some properties of the minimal marginal operator and the maximal marginal operator on the space of the games on convex geometries. 1991 Mathematics Subject Classi...cation: 90D12

In this paper, we prove some …xed point theorems for two hybrid pairs of mappings in 2-metric spaces by using some weaker conditions. Mathematics subject classi…cation: 47H10, 54H25. Key words and phrases: Coincidence point, common …xed point, compatible maps, weak commutativity of type (KB) :