reliability evaluation of a large-scale composite power system faces to numerous events/outage and consequently imposes an extensive burden of calculations. in order to simplify the problem, determination of an equivalent system for large-scale power system is inevitable. this paper proposes a framework as reduction technique to separate a composite power system to three areas: external area, o...

attention deficit hyperactivity disorder (adhd) and anxiety is the most common childhood psychiatric disorder. based on studies, these disorders are more prevalent in some chronic disease. this study aimed at investigating the prevalence of adhd and anxiety in children with malignancy and anxiety in their parents and comparing the results with those of the control group. one hundred, 3-15-year-...

the current study attempted to investigate the mathematical sturcuture of cost function of irrigated wheat crop in kurdistan province. the methodolgy is based on duality assumption. the sample size is 257 farmers for the agricultural year 2011-2012.data was collected byinterviewwith farmers and writing writerquestionnaire.the multistage cluster random sampling used. the results showed that, the...

Economics depends on the economic scale of planning. Economists study the characteristics of the production function, while community operating management focuses on demand realization, so that loss of sales or inventory prevents cost reductions and maximizes profits. However, companies with a lack of capacity need to achieve economies of scale and demand to realize them simultaneously, especia...