“…Moreover, it has been applied in human activity recognition [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ]. In HMM, it is commonly assumed that emission probabilities are raised from Gaussian mixture models (GMM) [ 82 , 83 , 84 , 85 , 86 , 87 ]. However, the assumption of Gaussianity could not be valid for all cases.…”