heavy metals are very important from environmental consideration due to their toxicity and accumulative properties. the aim of this study is the evaluation of spatial distribution of cr, co and ni in the surface soils of hamadan province. for this purpose, the surface soil samples (0-20 cm) were collected using systematic random sampling method and the concentration of heavy metals and some of ...

This paper reviews the recent developments in nonparametric identification of measurement error models and their applications in applied microeconomics, in particular, in empirical industrial organization and labor economics. Measurement error models describe mappings from a latent distribution to an observed distribution. The identification and estimation of measurement error models focus on h...