Research Article
Short-Time Fourier Transform and Decision Tree-Based Pattern Recognition for Gas Identification Using Temperature Modulated Microhotplate Gas Sensors
Figure 6
The feature vectors for three analytes (150 ppm carbon monoxide, 3000 ppm methane, and 50 ppm ethanol) with sawtooth modulated operating temperature ( s) at the first 11 frequencies: (a) mHz; (b) mHz; (c) mHz; (d) mHz; (e) mHz; (f) mHz; (g) mHz; (h) mHz; (i) mHz; (j) mHz; (k) mHz.
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