Table 1. Recall results of four algorithms.

Algorithm category	1	2	3	4	5	6	7	8
DD	79.11%	78.82%	78.38%	80.26%	79.95%	79.86%	79.30%	80.70%
SP	78.02%	77.32%	77.97%	79.90%	77.84%	78.16%	76.48%	75.83%
WSD	78.59%	78.01%	78.33%	77.04%	77.10%	78.70%	77.10%	76.84%
WSS	79.36%	77.01%	76.59%	78.84%	77.47%	77.89%	77.11%	77.74%