“…In the future, we will investigate clustering techniques [3,4,5,6,13,19,34] towards decomposing big data into multiple contexts, such that the training data obtained within each cluster can be more representative in the corresponding context. It is also worth to investigate granular computing techniques [7,14,31,35,41,44] for the decomposition of each class in more depth [20,22,24,30], towards further improvements of sample representativeness.…”