background: ageing of population worldwide will be responsible for a major increase of the incidence of osteoporosis in elderly. for the individual, osteoporotic fractures result in great disability as well as loss of quality of life and also represent an enormous burden for healthcare systems. this study was conducted to determine the prevalence of osteoporosis and it's association with s...

background: the extent of bone minerals density (bmd) gained during childhood is good index for bmd in adulthood. recent studies imply that exercise increases bmd however, there are rare studies about the best ages in which exercise gives the highest effect on children’s bmd. this study was carried out with the aim of comparing the extent of exercise effect on various ages on bmd of boys of ila...

4 Non-technical summary 5

Let X(t) (t Z) be a discrete stable random field. The problem of estimating the spectral density field based on X(t) is considered. Moments and the asymptotic moments of the spectral sample, the periodogram, based on X(t) are calculated.