this paper deals with the problem of forbidden states in discrete event systems modeled by petri net. to avoid the forbidden states, some constraints which are called generalized mutual exclusion constraints can be assigned to them. enforcing these constraints on the system can be performed using control places. however, when the number of these constraints is large, a large number of control p...

after the collapse of bipolar system in the world, different views and theories expressed by the scholars and thinkers about the future of the world and international system. one of them is the theory of “ the clash of civilizations” which was propounded in 1993 by the samuel huntington, the director of j.m.olin institute for strategic studies in harvard uni-versity. this theory caused some anx...

in recent years, in iran and other countries the power systems are going to move toward creating a competition structure for selling and buying electrical energy. these changes and the numerous advantages of dgs have made more incentives to use these kinds of generators than before. therefore, it is necessary to study all aspects of dgs, such as size selection and optimal placement and impact o...

Considering the fact that Iran is situated in an arid and semi-arid region, rainfall prediction for the management of water resources is very important and necessary. Researchers have proposed various prediction methods that have been utilized in such areas as water and meteorology, especially water resources management. The present study aimed at predicting rainfall amounts using Grey Predicti...

theory of ideas (muthul) in fact delineates the infrastructure of plato’s philosophy and metaphysics. it can be stated with certainty that by presenting this theory, plato intended to justify the generation of the mundus sensibili in view of its transitoriness and not being assuredly recognizable. encountering this theory, aristotle believes that professing to it would yield illogical results. ...

the nonlocal nonlinear buckling of a double layer graphene sheet (dlgs) covered by zinc oxide (zno) piezoelectric layers is investigated in this study. the surrounding circumstances of the system are considered as a pasternak foundation including spring constants and a shear layer. graphene sheets are subjected to longitudinal magnetic field and biaxial forces. on the other hand, the zno piezoe...

this paper assumes the cell formation problem as a distributed decision network. it proposes an approach based on application and extension of information theory concepts, in order to analyze informational complexity in an agent- based system, due to interdependence between agents. based on this approach, new quantitative concepts and definitions are proposed in order to measure the amount of t...

Electro-hydraulic systems with regards to the their specific features and applications among other industrial systems including mechanical, electrical and pneumatic systems, have been widely taken into consideration by the scientists and researchers. Due to the fact that the electro-hydraulic system is inherently a nonlinear system, has some problems such as signals saturation, nonlinear effici...