Appendix A
The term \(\frac{{\partial O^{(6)} \left( n \right)}}{{\partial \theta_{a} (n)}}\) for the actor network is described by the following equations:
$$\begin{aligned} \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial c_{j}^{i} \left( n \right)}} & = \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right)}}{{\partial c_{j}^{i} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 4 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 4 \right)} \left( n \right)}}{{\partial c_{j}^{i} \left( n \right)}}, \\ & = \frac{{\left( {1 - H_{l} + H_{r} } \right) \cdot \bar{O}_{i}^{\left( 3 \right)} \left( n \right) + \left( {1 - H_{r} + H_{l} } \right)\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }} \cdot O_{j}^{\left( 1 \right)} (n), \\ \end{aligned}$$
(53)
$$\begin{aligned} \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial s_{j}^{i} \left( n \right)}} & = \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right)}}{{\partial s_{j}^{i} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 4 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 4 \right)} \left( n \right)}}{{\partial s_{j}^{i} \left( n \right)}}, \\ & = \frac{{\left( {1 - H_{r} - H_{l} } \right) \cdot \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) - \left( {1 - H_{l} - H_{r} } \right) \cdot \bar{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }} \cdot \left| {O_{j}^{\left( 1 \right)} (n)} \right|, \\ \end{aligned}$$
(54)
$$\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} = \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} + \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}},$$
(55)
$$\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} = \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} + \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}},$$
(56)
$$\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} = \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underline{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} + \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \overline{O}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}}$$
(57)
$$\begin{aligned} \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial l^{i} \left( n \right)}} & = \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \underline{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial l^{i} \left( n \right)}} \\ & \quad + \,\left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial l^{i} \left( n \right)}}, \\ \end{aligned}$$
(58)
$$\begin{aligned} \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}} = \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}}\, \hfill \\ + \left( {\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}} + \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}} \right)\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}}, \hfill \\ \end{aligned}$$
(59)
$$\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial H_{l} \left( n \right)}} = \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial H_{l} \left( n \right)}} = \frac{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right)\left( {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) - \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} \right)} }}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }},$$
(60)
$$\frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial H_{r} \left( n \right)}} = \frac{{\partial O^{\left( 6 \right)} \left( n \right)}}{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial H_{r} \left( n \right)}} = \frac{{\sum\nolimits_{i = 1}^{M} {\bar{O}_{i}^{\left( 4 \right)} \left( n \right)\left( {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} \right)} }}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }}.$$
(61)
The derivatives in (55)–(61) are defined as:
$$\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}} = \frac{{H_{l} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right) - \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }},$$
(62)
$$\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}_{i}^{\left( 3 \right)} \left( n \right)}} = \frac{{\left( {1 - H_{l} } \right)\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 4 \right)} \left( n \right) - \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 5 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }},$$
(63)
$$\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}} = \frac{{\,\left( {1 - H_{r} \,} \right)\bar{O}_{i}^{\left( 4 \right)} \left( n \right) - \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)\,} }},$$
(64)
$$\frac{{\partial \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\partial \bar{O}_{i}^{\left( 3 \right)} \left( n \right)}} = \frac{{H_{r} \bar{O}_{i}^{\left( 4 \right)} \left( n \right) - \bar{O}^{\left( 5 \right)} \left( n \right)}}{{\sum\nolimits_{i = 1}^{M} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right) + \bar{O}_{i}^{\left( 3 \right)} \left( n \right)} }},$$
(65)
$$\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} = \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}\frac{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} = \left\{ {\begin{array}{*{20}l} {l^{i} {\bar{\varOmega }}^{i} \left( n \right)\frac{{O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)}}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{2} }},} \hfill & {O_{j}^{1} \left( n \right) < m_{j1}^{i} \left( n \right)} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right.,$$
(66)
$$\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} = \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial m_{j1}^{i} \left( n \right)}} = \left\{ {\begin{array}{*{20}l} {l^{i} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega } }^{i} \left( n \right)\frac{{O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)}}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{2} }},} \hfill & {O_{j}^{1} \left( n \right) > \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right.,$$
(67)
$$\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} = \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}\frac{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} = \left\{ {\begin{array}{*{20}l} {l^{i} {\bar{\varOmega }}^{i} \left( n \right)\frac{{O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)}}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{2} }},} \hfill & {O_{j}^{1} \left( n \right) > m_{j2}^{i} \left( n \right)} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right.,$$
(68)
$$\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} = \frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega } }^{i} \left( n \right)}}\frac{{\partial {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega } }^{i} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \underline{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial m_{j2}^{i} \left( n \right)}} = \left\{ {\begin{array}{*{20}l} {l^{i} {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega } }^{i} \left( n \right)\frac{{O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)}}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{2} }},} \hfill & {O_{j}^{1} \left( n \right) \le \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right.,$$
(69)
$$\frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} = \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}\frac{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} = \left\{ {\begin{array}{*{20}l} {l^{i} {\bar{\varOmega }}^{i} \left( n \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) < m_{j1}^{i} \left( n \right)} \hfill \\ {l^{i} {\bar{\varOmega }}^{i} \left( n \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) < m_{j2}^{i} \left( n \right)} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right.,$$
(70)
$$\begin{aligned} & \frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} = \frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial \sigma_{j}^{i} \left( n \right)}} \\ & = \left\{ {\begin{array}{*{20}l} {l^{i} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) \le \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ {l^{i} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) > \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ \end{array} ,} \right. \\ \end{aligned}$$
(71)
$$\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial l^{i} \left( n \right)}} = \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right) - \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{i}^{(3)} \left( {n - 1} \right),\frac{{\partial \bar{O}_{i}^{\left( 3 \right)} \left( n \right)}}{{\partial l^{i} \left( n \right)}} = {\bar{\varOmega }}^{i} \left( n \right) - \bar{O}_{i}^{(3)} \left( {n - 1} \right),$$
(72)
$$\begin{aligned} & \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}} = \frac{{\partial \bar{O}^{\left( 3 \right)} \left( n \right)}}{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}\,\frac{{\partial {\bar{\varOmega }}^{i} \left( n \right)}}{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \bar{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial O_{j}^{1} \left( n \right)}}\frac{{\partial O_{j}^{1} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}} \\ & = \left\{ {\begin{array}{*{20}l} { - l^{i} {\bar{\varOmega }}^{i} \left( n \right)O_{j}^{1} \left( {n - 1} \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) < m_{j1}^{i} \left( n \right)} \hfill \\ { - l^{i} {\bar{\varOmega }}^{i} \left( n \right)O_{j}^{1} \left( {n - 1} \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) < m_{j2}^{i} \left( n \right)} \hfill \\ {0,} \hfill & {\text{otherwise}} \hfill \\ \end{array} } \right., \\ \end{aligned}$$
(73)
$$\begin{aligned} & \frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}} = \frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}^{\left( 3 \right)} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)}}{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}\frac{{\partial \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{O}_{ij}^{\left( 2 \right)} \left( n \right)}}{{\partial O_{j}^{1} \left( n \right)}}\frac{{\partial O_{j}^{1} \left( n \right)}}{{\partial \alpha_{j} \left( n \right)}} \\ & = \left\{ {\begin{array}{*{20}l} { - l^{i} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)O_{j}^{1} \left( {n - 1} \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j2}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) \le \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ { - l^{i} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\varOmega }^{i} \left( n \right)O_{j}^{1} \left( {n - 1} \right)\frac{{\left( {O_{j}^{1} \left( n \right) - m_{j1}^{i} \left( n \right)} \right)^{2} }}{{\left( {\sigma_{j}^{i} \left( n \right)} \right)^{3} }},} \hfill & {O_{j}^{1} \left( n \right) > \frac{{m_{j1}^{i} \left( n \right) + m_{j2}^{i} \left( n \right)}}{2}} \hfill \\ \end{array} .} \right. \\ \end{aligned}$$
(74)
Appendix B
Proof
Consider the following Lyapunov candidate:
$$V_{g} \left( n \right) = \frac{1}{2}e_{g}^{2} \left( n \right).$$
(75)
□
For stable training algorithm, \(\Delta V_{g} \left( n \right)\) should be less than zero. Hence, the \(\Delta V_{g} \left( n \right)\) is calculated as the following equation:
$$\begin{aligned} \Delta V_{g} \left( n \right) & = \frac{1}{2}\left( {e_{g}^{2} \left( {n + 1} \right) - e_{g}^{2} \left( n \right)} \right) \\ & = \frac{1}{2}\left( {\left( {e_{g} \left( n \right) + \Delta e_{g} \left( n \right)} \right)^{2} - e_{g}^{2} \left( n \right)} \right) \\ & = \Delta e_{g} \left( n \right)\left( {e_{g} \left( n \right) + \frac{1}{2}\Delta e_{g} \left( n \right)} \right). \\ \end{aligned}$$
(76)
The \(\Delta V_{g} \left( n \right)\) can be rewritten as:
$$\Delta V_{g} \left( n \right) = \left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)\Delta \theta_{g} \left( n \right)\left( {e_{g} \left( n \right) + \frac{1}{2}\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)\Delta \theta_{g} \left( n \right)} \right).$$
(77)
Thus,
$$\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)\Delta \theta_{g} \left( n \right) = \left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)\Phi \left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} e_{g} \left( n \right),$$
(78)
where
$$\Phi = \left( {\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} \frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}} + \lambda_{g} \left( n \right)I} \right)^{ - 1} .$$
(79)
By using a matrix inversion lemma, we get [55]:
$$\left( {E + FGH} \right)^{ - 1} = E^{ - 1} - E^{ - 1} F\left( {G^{ - 1} + HE^{ - 1} F} \right)^{ - 1} \,HE^{ - 1} .$$
(80)
According to (80), (79) can be rewritten as:
$$\begin{aligned}\Phi & = \lambda_{g}^{ - 1} \left( n \right)I - \lambda_{g}^{ - 2} \left( n \right)\,\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} \left( {I + \frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}\lambda_{g}^{ - 1} \left( n \right)\,\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} } \right)^{ - 1} \frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}} \\ & = \lambda_{g}^{ - 1} \left( n \right)I - \lambda_{g}^{ - 1} \left( n \right)\,\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} \left( {\lambda_{g} \left( n \right)\,I + \frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)^{\rm T} } \right)^{ - 1} \frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}. \\ \end{aligned}$$
(81)
Using (81) and (78), we obtain
$$\left( {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right)\Delta \theta_{g} \left( n \right) = \lambda_{g}^{ - 1} \left( n \right)\,\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} \,e_{g} \left( n \right)\, - \lambda_{g}^{ - 1} \left( n \right)\,\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \left( {\lambda_{g} + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right)^{ - 1} e_{g} \left( n \right).$$
(82)
The time difference of the Lyapunov function \(\Delta V_{g} \left( n \right)\) can be given as:
$$\begin{aligned} \Delta V_{g} \left( n \right) & = - \frac{1}{2}e_{g}^{2} \left( n \right)\,\left( {\lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} - \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} } \right.\left. {\left[ {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right]^{ - 1} } \right) \\ & \quad \times \,\left( {2 - \lambda_{g}^{ - 1} \left( n \right)\,\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right. + \left. {\lambda_{g}^{ - 1} \left( n \right)\,\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \left[ {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right]^{ - 1} } \right). \\ \end{aligned}$$
(83)
Since
$$0 \le \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} ,$$
(84)
thus
$$\lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \le \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} + \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} .$$
(85)
By multiplying both sides of (85) by \(\left( {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right)^{ - 1}\), we get
$$\lambda_{g}^{ - 1} \left( n \right)\,\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \left( {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right)^{ - 1} \le \lambda_{g} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} ,$$
(86)
so that
$$0 \le \lambda_{g} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\| - \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \left( {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right)^{ - 1} .$$
(87)
Hence, in order that \(\Delta V_{g} \left( n \right) \le 0\),
$$0 \le \left( {2 - \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} + \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{4} \left( {\lambda_{g} \left( n \right) + \left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} } \right)^{ - 1} } \right).$$
(88)
Thus, the following constraint for the stability is
$$0 \le 2 - \lambda_{g}^{ - 1} \left( n \right)\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} ,$$
(89)
which means
$$\lambda_{g} \left( n \right) \ge \frac{1}{2}\left\| {\frac{{\partial e_{g} \left( n \right)}}{{\partial \theta_{g} \left( n \right)}}} \right\|^{2} .$$
(90)