Abstract. A multi-objective inventory model with demand dependent unit cost and leading time has been formulated with storage space, number of orders and production cost as constraints. In most of the real world situations the cost parameters the objective function and constraints of the decision makers are imprecise in nature. A demand dependent unit cost is assumed and solved using Karush Kuh...

In this work we introduce the notion of fuzzy congruence relation on an ndgroupoid and study conditions on the nd-groupoid which guarantee a complete lattice structure on the set of fuzzy congruence relations. The study of these conditions allowed to construct a counterexample to the statement that the set of fuzzy congruences on a hypergroupoid is a complete lattice.

In this paper, we establish some common fixed point theorems for fuzzy mappings satisfying fuzzy contractive conditions which are general than Chatterjee type and Kannan type fuzzy contractive conditions on closed balls in a complete metric space. Our results generalize the corresponding results in the current literature. AMS (2000) subject classification: 45S40 • 47H10 • 54H25

In this paper, the approximate controllability of impulsive linear fuzzy stochastic differential equations with nonlocal conditions in Banach space is studied. By using the Banach fixed point theorems, stochastic analysis, fuzzy process and fuzzy solution, some sufficient conditions are given for the approximate controllability of the system.

In this paper we introduce the notion of -chanable fuzzy metirc space. We give some conditions of which four self mappings of -chanable fuzzy metric space have a unique common fixed point. Also we characterize the conditions for two self mappings of -chanable fuzzy metric space have a unique common fixed point. Mathematics Subject Classification: 47H10, 54H25

in this paper, a model of an optimal control problem with chance constraints is introduced. the parametersof the constraints are fuzzy, random or fuzzy random variables. todefuzzify the constraints, we consider possibility levels.  bychance-constrained programming the chance constraints are converted to crisp constraints which are neither fuzzy nor stochastic and then the resulting classical op...

This paper introduces the concepts of fuzzy pseudo-open sets in fuzzy topological spaces and fuzzy pseudo-continuous functions between fuzzy topological spaces. Several characterizations of fuzzy pseudo-open sets are established. A conditions under which fuzzy hyper-connected spaces become fuzzy Baire spaces, is obtained by means of fuzzy pseudo-open sets. Several examples are given to illustra...

We define an 2-fuzzy congruence, which is a weakened fuzzy congruence, find the 2-fuzzy congruence generated by the union of two 2-fuzzy congruences on a semigroup, and characterize the 2-fuzzy congruences generated by fuzzy relations on semigroups. We also show that the collection of all 2-fuzzy congruences on a semigroup is a complete lattice and that the collection of 2-fuzzy congruences und...

In this paper we highlight the specific meaning of images of fuzzy sets under fuzzy relations in the context of fuzzy topology. More precisely we show that fuzzy modifiers taking direct and superdirect images of fuzzy sets under fuzzy pre-orderings are respectively closure and interior operators, inducing fuzzy topologies. Furthermore we investigate under which conditions the same applies to th...

in this paper, the fuzzy system has been used for fault detection and diagnosis of a yeast fermentation bioreactor based on measurements corrupted by noise. in one case, parameters of membership functions are selected in a conventional manner. in another case, using certainty factors between normal and faulty conditions the optimal values of these parameters have been obtained through the genet...