\begin{tikzpicture}[>=latex,line join=bevel,]
  \pgfsetlinewidth{1bp}
%%
\pgfsetcolor{black}
  % Edge: a -> b
  \draw [->] (82.074bp,38.164bp) .. controls (89.035bp,40.153bp) and (96.564bp,42.304bp)  .. (113.82bp,47.233bp);
  % Edge: aa -> b
  \draw [->] (93.314bp,77.212bp) .. controls (96.975bp,76.131bp) and (100.7bp,75.032bp)  .. (114.15bp,71.061bp);
  % Edge: c -> d
  \draw [->] (273bp,67.942bp) .. controls (273bp,65.452bp) and (273bp,62.962bp)  .. (273bp,50.234bp);
  % Edge: b -> c
  \draw [->] (196.27bp,70.892bp) .. controls (203.48bp,72.969bp) and (211.08bp,75.158bp)  .. (228.34bp,80.131bp);
  % Edge: d -> b
  \draw [->] (222.2bp,39.636bp) .. controls (216.93bp,41.157bp) and (211.56bp,42.703bp)  .. (196.27bp,47.108bp);
  % Node: aa
\begin{scope}
  \definecolor{strokecol}{rgb}{0.0,0.0,0.0};
  \pgfsetstrokecolor{strokecol}
  \draw (50bp,90bp) ellipse (50bp and 25bp);
  \draw (50bp,90bp) node {$\begin{array}{c}\text{generate}\\\text{arbitrary initial}\\ \mu_h, u_i\end{array}$};
\end{scope}
  % Node: a
\begin{scope}
  \definecolor{strokecol}{rgb}{0.0,0.0,0.0};
  \pgfsetstrokecolor{strokecol}
  \draw (50bp,29bp) ellipse (37bp and 18bp);
  \draw (50bp,29bp) node {generate $G_i$};
\end{scope}
  % Node: c
\begin{scope}
  \definecolor{strokecol}{rgb}{0.0,0.0,0.0};
  \pgfsetstrokecolor{strokecol}
  \draw (273bp,93bp) ellipse (51bp and 25bp);
  \draw (273bp,93bp) node {$\begin{array}{c}\text{compute}\\ \text{new columns }c_i\\ = \text{best path}(G_i)\end{array}$};
\end{scope}
  % Node: b
\begin{scope}
  \definecolor{strokecol}{rgb}{0.0,0.0,0.0};
  \pgfsetstrokecolor{strokecol}
  \draw (155bp,59bp) ellipse (46bp and 25bp);
  \draw (155bp,59bp) node {$\begin{array}{c}\text{compute}\\ \text{weights }w_a\\ \text{of arcs }a \in A_i\end{array}$};
\end{scope}
  % Node: d
\begin{scope}
  \definecolor{strokecol}{rgb}{0.0,0.0,0.0};
  \pgfsetstrokecolor{strokecol}
  \draw (273bp,25bp) ellipse (62bp and 25bp);
  \draw (273bp,25bp) node {$\begin{array}{c}\text{solve }LRMP \\ \text{and compute optimal}\\ \text{dual variables }\mu_h, u_i\end{array}$};
\end{scope}
%
\end{tikzpicture}