PRICAI 2021: trends in artificial intelligence 18th Pacific Rim International Conference on Artificial Intelligence, PRICAI 2021, Hanoi, Vietnam, November 8-12, 2021 : proceedings, part III - Pham, Duc-Nghia; Theeramunkong, Thanaruk; Governatori, Guido; Liu, Fenrong (Springer, 2021)