Population ageing and epidemiological transition are considered the outcome of demographic transition. The epidemiological transition is characterized by increasing prevalence of chronic conditions. Chronic conditions put older persons at increased risk of disability. Chronic conditions exacerbate frailty, in turn functional limitation. Alternatively age related frailty may also lead to occurrence of multiple chronic ailments, which may produce disability. Disability, albeit highly contested concept, in terms of impairments in physical strength and everyday self-maintenance tasks has received...

In turn, Chapters 2 and 3 address the construction of wavelet packets, selected results on wavelet packets, band-limited wavelet packets, characterisations of wavelet packets, multiresolution analysis (MRA) wavelet packets, pointwise convergence, the convergence of wavelet packet series and convolution bounds.