1. Louisiana State University,LSU Center for Computation & Technology,Baton Rouge,LA,U.S.A,70803
2. University of Stuttgart, Stuttgart,IPVS,Stuttgart,Germany,70174
3. University of Oregon,OACISS,Eugene,OR,U.S.A
4. Louisiana State University,Department of Physics and Astronomy,Baton Rouge,LA,U.S.A,70803