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...

parameter estimation of the nonlinear muskingum model is a highly nonlinear optimization problem. although various techniques have been applied to optimize the coefficients of the nonlinear muskingum flood routing models, but an efficient method for this purpose in the calibration process is still lacking. the accuracy of artificial bee colony (abc) algorithm is investigated in this paper to op...

in today’s world renewable energy is highly demanding because of increasing oil and fuelprices, desire and necessity to avert irreversible climate damage and also the unreliability of the non -renewablesources. in renewable energy, water is an important source. previously water is used only for survivalof human being as much as food but no attentionhas been givenen to economical use and conserv...

this study is focused on the development of a systematic computational approach which implements genetic algorithm (ga) to find the optimal rigorous kinetic models.a general kinetic model for hydrogenolysis of dibenzothiophene (dbt) based on langmuir-hinshelwood type has been obtained from open literature. this model consists of eight continuous parameters(e.g., arrhenus  and van't hoff paramet...

over the past few decades, several models such as the lp model have been used for managing watersheds and determining optimal cultivation pattern for agricultural planning. management and planning methods are the most important applied tools of management science for optimal allocating resources in order to gain the most profits in the different fields including natural resources, water resourc...

this paper presents a strategy for using harmony search algorithm in facility layout optimization problems. in this paper an adapted harmony search algorithm is developed for solving facility layout optimization problems. this method finds an optimal facility arrangement in an existing layout. two real-world case studies are employed to demonstrate the efficiency of this model. a comparison is ...

abstract the muskingum method is frequently used to route floods in hydrology. however, application of the model is still difficult because of the parameter estimation’s. recently, some of heuristic methods have been used in order to estimate the nonlinear muskingum model. this paper presents a efficient heuristic algorithm, simulated annealing, which has been used to estimate the three paramet...

a methodology is presented in this paper to find optimal location and dosage of chlorine injection in water distribution networks. the objective is to minimize the chlorine consumption while keeping the residual chlorine at each node within the standard range. unfortunately because of wrong water quality management in water distribution networks in many parts of the world, many problems such...

due to project evaluation complexity and resource constraints, the project portfolio optimization is numerous decision making challenges. hence, many researches have been done to introduce model and methods for portfolio optimization. but most of them have not considered the interaction between projects. considering the interactions between projects increase complexity of portfolio optimization...