in this paper after a general literature review on the concept of efficient frontier (ef), an important inadequacy of the variance based models for deriving efs and the high necessity for applying another risk measure is exemplified. in this regard for this study the risk measure of lower partial moment of the first order is decided to replace variance. because of the particular shape of the pr...

middle east is a strategic region because of its abundant oil reserves, hostile struggles among the countries, and threat of the radical groups. the countries of this region spend a large amount of their annual budgets on buying weapons and war armaments. the purpose of this paper is to study the impact of military expenditures on economic growth of oil and non-oil middle east countries by a dy...

data envelopment analysis (dea) is a method for measuring the efficiency of peer decision making units (dmus) which uses a set of inputs to produce a set of outputs. in some cases, dmus have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. one important issue in two-stage dea is the sensitivity of...

advanced data mining techniques can be used in universities classification, discovering specific patterns in the determination of successful students, design of a plan or a teaching method and finding critical points of financial management. in this article, we proposed a method to predict the rate of student enrollment in coming years. the data for this research were from data sets of voluntee...

recent bankruptcy of big companies all over the world and fluctuations in iran's stock market require that some methods be developed for the evaluation of companies' financial potential. different models are used for the prediction of bankruptcy and the evaluation of organizational financial situation. environmental changes and increasing competition among agencies led to companies&ap...

industrial wastewater included the dyes one of the important sources of environmental pollution that founded in loom wastewater which are harmful for human health and environment. therefore, the purpose of this research was investigated removal of rb5 dye from aqueous solution by using of adsorption onto activated red mud as an cheap adsorbent. this research was experimental- laboratorial study...

quantification of the habitat available for fish species named rainbow trout (oncorhynchusmykiss) were evaluated in lees ferry, colorado river using water depth, water temperature, sediment transport,flow velocity in 2004 as environmental index. for the flow velocity and temperature distribution calculationsin the river, the navier-stokes equation and energy conservation equations with finite v...

the modified nrtl (m-nrtl) model is used to represent the excess gibbs free energy of aqueous (alcohol + electrolyte) solutions. in this work, the m-nrtl model previously developed for representation of vapor-liquid equilibria for (polymer + salt + water) systems has been extended to represent liquid-liquid equilibria of (alcohol + salt + water) systems. the proposed extension is a modified of ...

formation of asphaltene deposition during oil production, processing and synthesis is known as a fundamental problem of petroleum reservoir worldwide. asphaltene is a petroleum fraction that can lead to increasing the operating costs in these industries. variations in operational pressure, temperature and fluid composition are generally the significant cause of asphaltene precipitation. in this...

realistic mobility models can demonstrate more precise evaluation results because their parameters are closer to the reality. in this paper a realistic fuzzy mobility model has been proposed. this model has rules which are changeable depending on nodes and environmental conditions. it seems that this model is more complete than other mobility models.after simulation, it was found out that not o...