1. TAIYO YUDEN CO., LTD.
2. Mineral Resources Research Group, Research Institute for Geo-Resources and Environment, Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST)
3. Inorganic Standards Group, Research Institute for Material and Chemical Measurement, National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST)