Robert McCormick Postdoctoral Fellow, Fermi Inst. of Nuclear Studies, Univ. of Chicago (1977-1979)
Staff Member, Dept. Terrestrial Magnetism, Carneige Inst. Wash. DC (1979-1983)
Adjunct Professor, Inst. of Geology and Dept. of Physics, Nat'l Taiwan Univ. (1984－)
Inst. of Earth Sciences, Academia Sinica, Research Fellow (1984-2005), Deputy Director (1987-1989), Director (2000-2004), Distinguished Research Fellow (2006－)
Visiting Professor of Geochemistry (fall/winter 1987), Div. of Geological & Planetary Sci., Calif. Inst. Tech.
Visiting Professor of Astrophysics (fall/winter 1992, 1997), Dept. of Astronomy, Univ. of Calif. at Berkeley
Inst. of Astronomy & Astrophysics, Academia Sinica, Director, Preparatory Office (1993-1994, 1996-1997), Research Fellow (joint appointment) since 1997, Adjunct Distinguished Research Fellow