in this paper, different input-oriented ratio-based dea (dea-r-i) models are proposed. by presenting the envelopment-additive-enhanced russell model based on the dea-r-i form, each decision making unit is evaluated and its efficiency score is calculated. also, by presenting the central resource allocation model based on the dea-r-i form, a suitable benchmark for all dmus is proposed by solving ...

H igh price volatility and the risk are the main features of commodity markets. One way to reduce this risk is to apply the hedging policy by future contracts. In this regard, in this paper, we will calculate the optimal hedging ratios for OPEC oil. In this study, besides the multivariate GARCH models, for the first time we use conditional copula models for modelling dependence struc...

the present essay intend to intoduce some vital established economic models of social welfare as welfare criticize and evaluate their capability and their explicative nature . the cotent is totally theoretical and therefore the evaluation will be done through hypothetical and abstract values and criteria . particularly the essay tries to go beyond exact socio - economic welfare models and to fi...

Application of agriculture residue especially in biochar form seems to be effective in the removal of contaminants such as nitrate pollution. The effectiveness of biochar produced from palm leaf residues (pyrolyzed at 600 ˚C) in the removal of nitrate from aqueous solution was studied at different pH. The pH value at the point of zero charges (pHpzc) and surface functional groups...

Lecture-based instructional models have been the mainstay of education for centuries. They excel primarily at delivering information from the one to the many. Educators refer to this model as "the sage on the stage". Clearly there are educators who relish this role and are strongly opposed to moving away from it. Yet, educational research and new innovative technologies are suggesting that lect...

There is a significant growth of behavior economics in the last decade. The goal of the behavior research is aimed at the deviations from rationality in order to improve the predictive power of economic models. In this paper, attached to the specific auditing process, I want to classify the neglecting relevant information due to judgment by representative which causes the bias, or the error of ...