Table 2 Non-radial basis functions [7]
From: A hybrid RNN-GPOD surrogate model for real-time settlement predictions in mechanised tunnelling
Region | Range of \({\varvec{\xi }}^{{\varvec{i}}}_{{\varvec{j}}}\) | \({\varvec{\phi }}^{{\varvec{L}}}\) | \({\varvec{\phi }}^{{\varvec{R}}}\) | \({\varvec{\phi }}^{{\varvec{\beta }}}\) |
|---|---|---|---|---|
I | \(\xi ^i_j \le -\gamma \) | \((-n\gamma ^{n-1})\xi ^i_j\) + \(\gamma ^n(1-n)\) | 0 | \(\xi ^i_j\) |
II | \(-\gamma \le \xi ^i_j\le 0\) | \((\xi ^i_j)^n\) | 0 | \(\xi ^i_j\) |
III | \(0\le \xi ^i_j\le \gamma \) | 0 | \((\xi ^i_j)^n\) | \(\xi ^i_j\) |
IV | \(\xi ^i_j \ge \gamma \) | 0 | \((n\gamma ^{n-1})\xi ^i_j\) + \(\gamma ^n(1-n)\) | \(\xi ^i_j\) |