[IEEE 2013 IEEE RIVF International Conference on Computing & Communication Technologies, Research, Innovation, and Vision for the Future (RIVF) - Hanoi, Vietnam (2013.11.10-2013.11.13)] The 2013 RIVF International Conference on Computing & Communication Technologies - Research, Innovation, and Vision for Future (RIVF) - Improvement of naturalness for an HMM-based Vietnamese speech synthesis using the prosodic information