Domestic wastewater treatment covers the processes that used to treat waters that have been polluted by commercial or anthropogenic activities prior to its discharge into the environment or its re-use. Data Envelopment Analysis was applied to evaluate six urban wastewater treatment plants efficiency in three stages with fuzzy data and discretionary and non- discretionary inputs in Iran. Stream flow, Chemical Oxygen Demand and Total Suspended Solids were considered as input variables. In this paper a fuzzy network Data Envelopment Analysis model is proposed and solved with GAMS software. Results showed that showed that Bandar Torkman has the best performance between these waste water treatment plants and Babol and yasreb waste water treatment plants do not operate well. تفاصيل المقالة

The outbreak of the coronavirus has caused a recession in most countries, reducing the budgets of organizations in all sectors, including government, business and academia. After the beginning of the epidemic, countries responded to the disease in various ways. This paper evaluates the performance of OECD member countries using network data envelopment analysis method. For this purpose, effective financial and health indicators were identified. Unfavorable and flexible data were identified in various stages and a suitable model was presented. The results of the implementation of the model provide a good insight into the financial and health policies of the above countries. تفاصيل المقالة

In today's world, due to the tight competition of companies, sensitivity analysis is of special importance for managers in maintaining their position. This issue can determine new strategies and distance from competitors. In this paper, a two-stage network structure was considered. The main goal is to determine a range for the inputs of each decision-making unit so that the efficiency of the entire network does not change. These changes have been made both in each entry and in all entries. With the help of data envelopment analysis models, a method has been designed to calculate a stability zone. The feasibility of this method has been checked with a set of data. تفاصيل المقالة