CAJ | 학술논문

根据可用性测试过程中用户皮肤电水平（skin conductance level，SCL）的变化，提出了基于总体平均经验模式分解（ensemble empirical mode deeomposition，EEMD）技术的用户SCL信号趋势和变化特征提取方法。首先，应用EEMD技术对SCL信号进行分解，得到若干独立的基本模式分量及趋势项；然后，对基本模式分量进行显著性检验，进而实现信号的去噪去趋势重构，得到用户SCL的变化特征。实验结果表明：界面的可用性问题使得用户SCL单调趋势变得不明显；当用户遇到可用性问题时，SCL去噪去趋势重构信号波动幅度明显变大，Wilcoxon符号秩检验表明不同阶段用户SCL去噪去趋势重构信号功率差异显著。因此，基于EEMD的信号处理方法能有效支撑可用性测试过程中用户SCL变化的分析。
근거가용성측시과정중용호피부전수평（skin conductance level，SCL）적변화，제출료기우총체평균경험모식분해（ensemble empirical mode deeomposition，EEMD）기술적용호SCL신호추세화변화특정제취방법。수선，응용EEMD기술대SCL신호진행분해，득도약간독립적기본모식분량급추세항；연후，대기본모식분량진행현저성검험，진이실현신호적거조거추세중구，득도용호SCL적변화특정。실험결과표명：계면적가용성문제사득용호SCL단조추세변득불명현；당용호우도가용성문제시，SCL거조거추세중구신호파동폭도명현변대，Wilcoxon부호질검험표명불동계단용호SCL거조거추세중구신호공솔차이현저。인차，기우EEMD적신호처리방법능유효지탱가용성측시과정중용호SCL변화적분석。
To extract the features of users＇ skin conductance level change during the usability testing, a method of ensemble empirical mode decomposition （EEMD） is proposed. SCL signal is decomposed into several in- trinsic mode functions （IMF） and a trend item with the EEMD. The IMFs are analyzed with significance test, and then de-noising and de-trending recon- struction is carried out to extract the change features of SCL. The results show that usability problems lead to no significant decreasing or increasing trend of users＇ SCL during usability testing, and the fluc-tuation range of reconstructed signal gets larger when users are facing usability problems. The results of Wilcoxon signed rank test show that power in differ- ent stages change significantly. Hence, the results suggest that the EEMD - based method can support users＇ SCL analyzing effectively during usability tes- ting.