Abstract Various methods have been proposed to measure vibration frequency. However, mechanical systems are not efficient as they be attached the object of interest. So, measurements precise when a new mass is introduced surface. Besides, obtaining power and phase distribution on whole surface vibrating possible through using accelerometers or other vibrometers. Out-of-plane detection was previ...

In previously published articles, our research group has developed the Haphazard Intentional Sampling method and compared it to Rerandomization proposed by K.Morgan D.Rubin. this article, we compare both methods pure randomization used for Epicovid19 survey, conducted estimate SARS-CoV-2 prevalence in 133 Brazilian Municipalities. We show that intentional sampling can either substantially reduc...