1. GIGA Group, Faculty of Engineering, University of Antioquia, calle 67 No. 53-108, bloque 20-249, Medellín, Colombia, Telephone: +57 4 2105596, Telefax: +81 3 5841 8504,
2. Geotechnical Engineering Group, Department of Civil Engineering, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan Telephone: +81 3 5841 6123, Telefax: +81 3 5841 8504,
3. Geotechnical Engineering Group, Department of Civil Engineering, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan, Telephone: +81 3 5841 6120, Telefax: +57 4 210 5514,