drought is universal phenomenon that can occur everywhere and can cause harmful impacts on human beings and natural ecosystems. thus, it is very important to study drought character ristics part of for water resources management. in this study, the standardized precipitation index (spi) is used for drought frequency analysis in isfahan province. after collecting the precipitation data in the pr...

selection of an appropriate set of information system (is) projects is a critical business activity which is very helpful to all organizations. in this paper, after describing real is project selection problem of iran ministry of commerce (moc), we introduce two data envelopment analysis (dea) models. then, we show applicability of introduced models for identifying most efficient is project fro...

although economists and entrepreneurs had been aware of the impact of economies of scale on average cost, no comprehensive theory was introduced until 1950s. economies of scale is used by economist as a practical measure for evaluating the extent of competition (monopoly) in real markets. there are two primary aims of this paper: 1) to introduce theoretical aspects of economies of scale, 2) to ...

in data envelopment analysis, the relative efficiency of a decision making unit (dmu) is defined as the ratio of the sum of its weighted outputs to the sum of its weighted inputs allowing the dmus to freely allocate weights to their inputs/outputs. however, this measure may not reflect a the true efficiency of a dmu because some of its inputs/outputs may not contribute reasonably in computing t...

The existing data envelopment analysis (DEA) models for measuring the relative efficiencies of a set of decision making units (DMUs) using various inputs to produce various outputs are limited to crisp data. The notion of fuzziness has been introduced to deal with imprecise data. Fuzzy DEA models are made more powerful for applications. This paper develops the measure of efficiencies in input o...