%------------------------------------------------------------------------------------------------------------
%%%  文法驱动的统计机器翻译流程
\begin{center}
\begin{tikzpicture}
\begin{scope}

\tikzstyle{datanode} = [minimum width=7em,minimum height=1.7em,fill=blue!20,rounded corners=0.3em];
\tikzstyle{modelnode} = [minimum width=7em,minimum height=1.7em,fill=red!20,rounded corners=0.3em];
\tikzstyle{decodingnode} = [minimum width=7em,minimum height=1.7em,fill=green!20,rounded corners=0.3em];

\node [datanode,anchor=north west,minimum height=1.7em,minimum width=8em] (bitext) at (0,0) {{ \small{训练用双语数据}}};
\node [modelnode, anchor=north west,minimum height=1.7em,minimum width=8em] (gi) at ([xshift=2em,yshift=-0.2em]bitext.south east) {{ \small{文法（规则）抽取}}};
\node [datanode,anchor=north east,minimum height=1.7em,minimum width=8em] (birules) at ([xshift=-2em,yshift=-0.2em]gi.south west) {{ \small{同步翻译文法}}};
\node [modelnode, anchor=north west,minimum height=1.7em,minimum width=8em] (training) at ([xshift=2em,yshift=-0.2em]birules.south east) {{ \small{特征值学习}}};
\node [datanode,anchor=north east,minimum height=1.7em,minimum width=8em] (model) at ([xshift=-2em,yshift=-0.2em]training.south west) {{ \small{翻译模型}}};
\node [decodingnode, anchor=north west,minimum height=1.7em,minimum width=8em] (tuning) at ([xshift=2em,yshift=-0.2em]model.south east) {{ \small{特征权重调优}}};
\node [datanode,anchor=north east,minimum height=1.7em,minimum width=8em] (tuningdata) at ([xshift=-2em,yshift=-0.2em]tuning.south west) {{ \small{调优用双语数据}}};
\node [decodingnode, anchor=north west,minimum height=1.7em,minimum width=8em] (decoding) at ([xshift=2em,yshift=-0.2em]tuningdata.south east) {{ \small{解码新句子}}};

\node [datanode,anchor=south west,minimum height=1.7em,minimum width=8em] (monotext) at ([xshift=2em,yshift=0.2em]training.north east) {{ \small{目标语数据}}};
\node [modelnode,anchor=south west,minimum height=1.7em,minimum width=8em] (lm) at ([xshift=2em,yshift=0.2em]tuning.north east) {{ \small{$n$-gram语言建模}}};
\node [datanode,anchor=south west,minimum height=1.7em,minimum width=8em] (lmmodel) at ([xshift=2em,yshift=0.2em]decoding.north east) {{ \small{语言模型}}};

\draw [->,very thick] ([yshift=-0.3em,xshift=0.1em]bitext.east) -- ([yshift=0.1em]gi.north west);
\draw [->,very thick] ([yshift=-0.1em]gi.south west) -- ([yshift=0.3em,xshift=0.1em]birules.east);
\draw [->,very thick] ([yshift=-0.3em,xshift=0.1em]birules.east) -- ([yshift=0.1em]training.north west);
\draw [->,very thick] ([yshift=-0.1em]training.south west) -- ([yshift=0.3em,xshift=0.1em]model.east);
\draw [->,very thick] ([yshift=-0.3em,xshift=0.1em]model.east) -- ([yshift=0.1em]tuning.north west);
\draw [->,very thick] ([yshift=-0.1em]tuning.south) -- ([yshift=0.1em]decoding.north);
\draw [->,very thick] ([yshift=0.3em,xshift=0.1em]tuningdata.east) -- ([yshift=-0.1em]tuning.south west);

\draw [->,very thick] ([yshift=-0.1em]monotext.south) -- ([yshift=0.1em]lm.north);
\draw [->,very thick] ([yshift=-0.1em]lm.south) -- ([yshift=0.1em]lmmodel.north);
\draw [->,very thick] ([yshift=0.3em,xshift=-0.1em]lmmodel.west) -- ([yshift=-0.1em]tuning.south east);
\draw [->,very thick] ([yshift=-0.3em,xshift=-0.1em]lmmodel.west) -- ([yshift=0.1em]decoding.north east);
\end{scope}
\end{tikzpicture}
\end{center}