Table 2.
Feature extraction specifications by sensing Modality.
| Sensing modality | CNN/Processing architecture | Extracted features | Feature dimension | Design application |
|---|---|---|---|---|
| Visual Cameras | ResNet-50 backbone | Crowd density maps, movement vectors, activity heatmaps | 2048-dim embedding | Capacity management, flow optimization |
| Visual Cameras | YOLO v5 object detection | Person count, spatial distribution, dwell time | 512-dim per region | Space utilization analysis |
| Acoustic Sensors | MFCC extraction (13 coefficients) | Frequency signatures (50–8000 Hz), sound pressure levels | 39-dim (MFCC + Δ + ΔΔ) | Activity level detection |
| Acoustic Sensors | Spectral analysis | Social interaction indices, ambient noise | 64-dim spectral features | Comfort assessment |
| Environmental | Statistical aggregation | Temperature (± 0.1 °C), humidity (± 2% RH), PM2.5, illuminance | 8-dim parameter vector | Environmental quality optimization |
| Motion Detectors | Binary pattern analysis | Trajectory data, pathway usage frequency | 128-dim spatial grid | Circulation planning |
This layer utilizes convolutional neural networks for visual feature extraction, spectral analysis algorithms for acoustic processing, and statistical methods for environmental parameter characterization. The mathematical foundation for feature extraction can be expressed through the transformation function:.