Ramadhan, N.G., Putrada, A.G. and Abdurohman, M. 2019. Improving Smart Lighting with Activity Recognition Using Hierarchical Hidden Markov Model. Indonesia Journal on Computing (Indo-JC). 4, 2 (Sep. 2019), 43-54. DOI:https://doi.org/10.34818/INDOJC.2019.4.2.307.