مقاله ISI چاپ شده در مجله علمی ساینتیا ایرانیکا (Scientia Iranica), شماره 105، چاپ سال 2015 In this paper, a new model is developed considering diversity of service in service centers location problem. It is assumed that different services can be provided at each service center. The model has three objective functions including: minimizing the sum of customers’ travel time and waiting time in service centers, balancing service loads among the given centers, and minimizing the total establ ...