Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J. Brock is a CFA and CPA with more ...

Definition: Quota sampling is a sampling methodology wherein data is collected from a homogeneous group. It involves a two-step process where two variables can be used to filter information from the ...

Abstract: We proved that the phaseless sampling (PLS) in the linear-phase modulated shift-invariant space (SIS) V (eiα·φ), α = 0, is impossible even though the real-valued function φ enjoys the full ...