in the field of health losses resulting from failure to establish the facilities in a suitable location and the required number, beyond the cost and quality of service will result in an increase in mortality and the spread of diseases. so the facility location models have special importance in this area. in this paper, a successively inclusive hierarchical model for location of health centers i...

this paper offers an approach that could be useful for diverse types of layout problems or even area allocation problems. by this approach there is no need to large number of discrete variables and only by few continues variables large-scale layout problems could be solved in polynomial time. this is resulted from dividing area into discrete and continuous dimensions. also defining decision var...

This paper proposes a new location problem of competitive facilities, e.g. shops. In the most studies of competitive facility location, the distance between the facilities and their customers is represented as the Euclid distance. The proposing location problem introduces the A-distance, proposed by Widmayer etc., for representing the situation that the directions which customers can move are g...