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[Studies in Computational Intelligence 481] Artur Babiarz, Robert Bieda, Karol Jędrasiak, Aleksander Nawrat (auth.), Aleksander Nawrat, Zygmunt Kuś (eds.) - Vision Based Systemsfor UAV Applications (2013, Sprin

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Selection of Individual Gait Features Extracted by MPCA 261<br />

Table 3. Two class problems, experiment 1<br />

TP TN FP FN Precision Sensitivity Sensibility<br />

FYC 8 28 2 2 90% 93% 80%<br />

HY 3 23 7 7 65% 77% 30%<br />

LJG 2 22 8 8 60% 73% 20%<br />

LQF 5 25 5 5 75% 83% 50%<br />

The obta<strong>in</strong>ed average identification precision is def<strong>in</strong>itely better <strong>in</strong> compar<strong>in</strong>g<br />

to random guess<strong>in</strong>g, however it seems that selected gaits are very discrim<strong>in</strong>ative<br />

and should allow for more accurate identification. That is a reason we repeated<br />

experiment with simultaneous presentation of the tra<strong>in</strong><strong>in</strong>g and test sets. It means,<br />

that volunteers observed and analyzed all gaits <strong>in</strong> the same moment and their task<br />

was only to match samples of the tra<strong>in</strong><strong>in</strong>g and test sets. In such a case, the identification<br />

is <strong>in</strong>dependent on human abilities to memorize noticed <strong>in</strong>dividual gait features<br />

and relies only the observed gait similarities.<br />

Table 4. Identification performed by human, experiment 2<br />

V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 AVG<br />

FYC 1 1 1 1 1 1 1 1 1 1 100%<br />

HY 1 1 1 1 1 1 1 1 1 1 100%<br />

LJG 1 0 1 1 1 1 1 1 1 1 90%<br />

LQF 1 0 1 1 1 1 1 1 1 1 90%<br />

AVG 100% 50% 100% 100% 100% 100% 100% 100% 100% 100% 95%<br />

The results of identification with simultaneous presentation of the tra<strong>in</strong><strong>in</strong>g and<br />

test sets are presented <strong>in</strong> Tab. 4, Tab. 5 and Tab. 6. This time they are very close<br />

to the ideal case of 100% of classification accuracy, only s<strong>in</strong>gle volunteer V2<br />

mistook actors LJG and LQF. As we supposed humans are easily able to recognize<br />

persons on the basis of their gait <strong>in</strong>spection, but more challeng<strong>in</strong>g task is to keep<br />

<strong>in</strong> m<strong>in</strong>d discovered <strong>in</strong>dividual gait features. Probably longer teach<strong>in</strong>g phase would<br />

improve the results of the experiment 1. The number of persons to identify by<br />

human is obviously limited, because of restriction of simultaneous presentation<br />

and observation.<br />

On the basis of the experiment performed we can state the thesis that gait allows<br />

to high precision human identification.<br />

Table 5. Confusion matrix, experiment 2<br />

FYC HY LJH LQF<br />

FYC 10 0 0 0<br />

HY 0 9 1 0<br />

LJG 0 1 9 0<br />

LQF 0 0 0 10

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