the present study is an attempt to investigate some features of radial basis functions (rbfs) approximation methods related to variational problems. thereby authors applied some properties of rbfs to develop a direct method which reduces constrained variational problem to a static optimization problem. to assess the applicability and effectiveness of the method, some examples are examined. dyna...

The log-logistic distribution is widely used in different fields of study such as survival analysis, hydrology, insurance, and economics. Recently, Ahsanullah Alzaatreh studied the best linear unbiased estimators for location scale parameters three-parameter model. same authors also propose a shift-invariant Hill estimator unknown shape parameter. In this work, we new estimation method We deriv...

In the present study, three-parameter one-dimensional vertical infiltration equation recently proposed by Poulovassilis and Argyrokastritis is examined. The includes saturated hydraulic conductivity (Ks), soil sorptivity (S), an additional parameter c; it valid for all times. c a fitting that depends on type of porous medium. characterized incorporation exact contribution pressure head gradient...