| _ | tough | _ |
|---|---|---|
| Challenging | tough | samples in unsupervised domain adaptation |
| Static facial expression analysis in | tough | conditions: Data, evaluation protocol and benchmark |
| Video transmission technology with effective error protection and | tough | synchronization for wireless channels |
| Wearable sensor detects stress in sweat: Cortisol is key to tracking stress, but it's | tough | to measure in an instant-[News] |
| _ | toughened | _ |
|---|---|---|
| Inspection and Image Analysis of Nickel Sulphide Inclusions in | toughened | Glass Panels |
| _ | toughest | _ |
|---|---|---|
| Sports: 3-D TV's | toughest | challenge |