Table 2: Experimental results of learning time on different digit (sec).

Training stageTesting stage

“0”“2”“4”“6”“8”“0”“2”“4”“6”“8”

KPCA1.75 ± 0.0551.74 ± 0.0181.74 ± 0.0211.76 ± 0.0361.74 ± 0.0300.358 ± 0.0220.351 ± 0.0130.357 ± 0.0120.352 ± 0.0110.354 ± 0.011

IKPCA-RS43.68 ± 0.04941.32 ± 0.03843.21 ± 0.06844.75 ± 0.07442.87 ± 0.0590.221 ± 0.0090.243 ± 0.0110.208 ± 0.0140.169 ± 0.0170.214 ± 0.008

INKPCA23.67 ± 0.03222.13 ± 0.03823.91 ± 0.04123.10 ± 0.04722.13 ± 0.0350.360 ± 0.0230.358 ± 0.0140.353 ± 0.0120.355 ± 0.0120.352 ± 0.011

TP-IKPCA1.89 ± 0.0193.06 ± 0.0171.67 ± 0.0431.40 ± 0.0242.27 ± 0.0310.181 ± 0.0120.251 ± 0.0080.162 ± 0.0160.144 ± 0.0130.199 ± 0.010

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