Affiliation: | Delft University of Technology, Department of Geotechnology, PO Box 5028, NL-2600 GA Delft, the Netherlands. E-mail:;Research Institute of Innovative Technology for the Earth, 9-2, Kizugawa-dai, Kizu-Cho, Soraku-Gun, Kyoto 619-0292, Japan;Oyo corporation, 43, Miyukigaoka, Tsukuba, Ibaraki 305-0841, Japan;National Institute of Advanced Industrial Science and Technology, Geophysical Exploration Section, 1-1-3, Higashi, Tsukuba, Ibaraki 305-8567, Japan |