A solid phase extraction procedure for simultaneous separation and preconcentration of traceamounts of Cu+2 ion from various real samples prior to its determination by flame atomicabsorption spectrometry has been developed. The proposed method is based on the utilization ofmultiwalled carbon nanotube in combination with Cupferron ligand as a solid phaseextractant. The influences of the analytic...

This paper proposes a simple goodness-of-fit test based on the sample covariance. It is shown that this test is preferable for alternatives of increasing and unimodal failure rate. Critical values for various sample sizes are determined by means of Monte Carlo simulations. We compare the test based on the sample covariance with tests based on Hoeffding's maximum correlation. The usefulness o...

in order to determine the best form factor formula for loblolly pine (pinus taeda l.) plantations in talesh (western guilan province-iran), a number of 110 trees were selected based on their distribution in diameter classes, from 12 to 34 cm (in a two- cm diameter interval). first, several quantitative factors including diameter at breast height, diameter at 0.65 m of height, and diameter at st...

this paper investigates the effect of exchange rate uncertainty on the iran’s import trade. the exchange rate ‎uncertainty series were generated utilizing the tarch model. this model analyzes the asymmetric effects. the analysis of uncertainty and asymmetry ‎of the exchange rate shows significant tarch ‎effect on iran’s exchange rates‎. the findings of the study indicate negative shocks (bad ne...

We study approaches to learning an exercise policy for American options directly from real data. We investigate an approximate policy iteration method, namely, least squares policy iteration (LSPI), for the problem of pricing American options. We also extend the standard least squares Monte Carlo (LSM) method of Longstaff and Schwartz, by composing sample paths from real data. We test the perfo...