background : a detailed study of hidden and hard to reach populations in order to identify their characteristics is essential because they endanger the health of the society by their dangerous behaviors. however, sampling in these populations through conventional sampling methods is impossible due to reasons such as being hidden and lacking a precise frame. methods: in this article, applicable ...

This paper describes Data-Weighted-Averaging (DWA) algorithms for multibit complex bandpass ∆ΣAD modulators with arbitrary signal bands. In most of bandpass ∆ΣAD modulators, their sampling frequency is chosen as four times of the center frequency of their signal band in order to simplify the following digital filter design. But with this relationship, their performance would be limited by the t...

The focus of this paper is to consider the compressed sensing problem. It is stated that the compressed sensing theory, under certain conditions, helps relax the Nyquist sampling theory and takes smaller samples. One of the important tasks in this theory is to carefully design measurement matrix (sampling operator). Most existing methods in the literature attempt to optimize a randomly initiali...

the focus of this paper is to consider the compressed sensing problem. it is stated that the compressed sensing theory, under certain conditions, helps relax the nyquist sampling theory and takes smaller samples. one of the important tasks in this theory is to carefully design measurement matrix (sampling operator). most existing methods in the literature attempt to optimize a randomly initiali...