The Fama-Macbeth (1973) rolling-β method is widely used for estimating risk premiums, but its inherent errors-in-variables bias remains an unresolved problem, particularly when using individual assets or macroeconomic factors. We propose a solution with a particular instrumental variable, β calculated from alternate observations. The resulting estimators are unbiased. In simulations, we compare...

Five new mathematical triple fouling models were developed to explore the flux decline behavior during the microfiltration. The first model was developed by the assumption of the successive effects of standard mechanism, intermediate pore blockage and cake formation by using the standard blocking flux expression in the model calculations. The second and third models also obtained by the success...

seismic behavior of a rockfill dam with asphalt-concrete core has been studied utilizing numerical models with material parameters determined by laboratory tests. the case study selected for these analyses, is the meyjaran asphalt core dam, recently constructed in northern iran, with 60 m height and 180 m crest length. the numerical analyses have been performed using a nonlinear three dimension...