List of Articles Open Access Article Abstract Page Full-Text 1 - Proposing a mathematical programming model for load balancing in mobile cellular networks Shahram Saeidi Sahar Khoshfetrat Open Access Article Abstract Page Full-Text 2 - A Decision-Making Model for Supplier Selection Based on Data Envelopment Analysis Hoda Moradi Mehdi abbaszadeh Open Access Article Abstract Page Full-Text 3 - Optimum placement of Distributed Generation Sources to Minimize Losses and to Improvement Voltage Profile of Distribute Network Using Data Envelopment Analysis Method Hossein Tohidi Open Access Article Abstract Page Full-Text 4 - Estimation of inputs and outputs in the general production possibility set with negative data based on the inverse DEA Javad Gerami