INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.|INRIA/IRISA/GenScale, Campus de Beaulieu, 35042 Rennes Cedex, France and Department of Computer Science and Engineering, Pennsylvania State University, PA 16802, USA.