This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessArticle by 1,*,†, 2,†, 2 and 2 1 Singtel Cognitive and Artificial Intelligence Lab ([email protected]), Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore 2 School of Computer Science and Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798, Singapore * Author to whom correspondence should be addressed.