Table 1. Main symbols’ definition.
| Symbol | Definition | Symbol | Definition |
|---|---|---|---|
| a i | Visible units bias | Z | Training set |
| b j | Hidden units bias | x | Training data |
| w ij | Weight between visible units and hidden unit | y i | Label of training data |
| V i | Text feature state of visible unit i | k | The rating of movies |
| h j | Text feature state of hidden unit j | θ | Function parameter |
| S | Activation probability | M | Number of movies |
| Δwij | Updating the value of the weight | N | Number of users |
| Δai | Updating the value of visible units | p(y = j|x) | Probability of each x belonging to each category j |
| Δbj | Updating the value of hidden units | j | Number of categories |
| ɛ | Learning rate | ||
| <.>data | Value of visible units i multiplied by hidden units j before reconstruction | ||
| <.>recon | Value of visible units i multiplied by hidden units j after reconstruction |