Classification Approach for Attention Assessment via Singular Spectrum Analysis Based on Single-Channel Electroencephalograms.

Attention refers to the human psychological ability to focus on doing an activity. The attention assessment plays an important role in diagnosing attention deficit hyperactivity disorder (ADHD). In this paper, the attention assessment is performed via a classification approach. First, the single-channel electroencephalograms (EEGs) are acquired from various participants when they perform various activities. Then, fast Fourier transform (FFT) is applied to the acquired EEGs, and the high-frequency components are discarded for performing denoising. Next, empirical mode decomposition (EMD) is applied to remove the underlying trend of the signals. In order to extract more features, singular spectrum analysis (SSA) is employed to increase the total number of the components. Finally, some typical models such as the random forest-based classifier, the support vector machine (SVM)-based classifier, and the back-propagation (BP) neural network-based classifier are used for performing the classifications. Here, the percentages of the classification accuracies are employed as the attention scores. The computer numerical simulation results show that our proposed method yields a higher classification performance compared to the traditional methods without performing the EMD and SSA.

[Study on separation and purification of anthraquinones in radix et rhizoma rhei by D301 macroporous resin].

OBJECTIVE: The parameters of absorption and purification of total anthraquinones in Radix Et Rhizoma Rhei by D301 macroporous resin were investigated in this paper. METHOD: HPLC was used to analyze the content of total anthraquinones in Radix Et Rhizoma with emodin as control. RESULT: The appropriate adsorption conditions were: concentration of extract 0.5 g x mL(-1); pH 9; flow rate 1 BV x h(-1). When the 75% ethanol was used as elution and the concentration of HCl was 0.1 mol x L(-1), and the flow rate was 1.0 BV x h(-1), the effect of desorption was satisfactory. CONCLUSION: D301 resin provided a good effect on the exchang and absorption of total anthraquinones in Radix Et Rhizoma.