Figure 6.

An illustration of the sub-task information generator. A sequence of sub-task labels $D_g=\left\{{\acute{c}}_i^g|i=1, 2,\dots ,n_g\right\}$ is obtained based on a sequence of modified class labels $D_r=\left\{{\acute{c}}_j^r|j=1, 2,\dots ,n_s\right\}$. For the first $n_s-1$ modified class labels, each ${\acute{c}}_j^r$ maps to a sequence of sub-task labels {${\acute{c}}_i^g$,${\acute{c}}_{i+1}^g$,…,${\acute{c}}_{i+ss-2}^g,{\acute{c}}_{i+ss-1}^g$ }, where $i=1+ss\times \left(j-1\right)$. Finally, a sequence of sub-task labels {${\acute{c}}_i^g$,${\acute{c}}_{i+1}^g$,…,${\acute{c}}_{i+ws-2}^g,{\acute{c}}_{i+ws-1}^g$ } is obtained from the last modified class label ${\acute{c}}_{n_s}^r$.