“…-50-class: Original 50 classes are utilized using two experimental protocols: leave-one-out (50-LOO) [4,17,29] and 4-fold cross validation (50-4fold) [14,16]. -9-class and 8-class: Original 50 classes of sequences are divided into 9 semantic categories [29,6] consisting of "boiling water" (8), "fire" (8), "flowers" (12), "fountains" (20), "plants" (108), "sea" (12), "smoke" (4), "water" (12), and "waterfall" (16), where the numbers in parentheses take account of sequences in each class.…”