Mechanical Engineering / Statistical Signal Processing / Digital Signal Processing / Maximum Likelihood / EM algorithm / Potassium / Expectation Maximization / Poisson Process / Lower Bound / Statistical Model / Digital signal / Gamma Ray / Electrical And Electronic Engineering / Poisson Model / maximum likelihood estimate / Potassium / Expectation Maximization / Poisson Process / Lower Bound / Statistical Model / Digital signal / Gamma Ray / Electrical And Electronic Engineering / Poisson Model / maximum likelihood estimate