1. GEMS Informatics Center Univ. of Minnesota—Twin Cities St. Paul MN 55108 USA
2. Research Computing Univ. of Minnesota—Twin Cities Minneapolis MN 55455 USA
3. Dep. of Applied Economics U niv. of Minnesota—Twin Cities St. Paul MN 55108 USA
4. Computational Research Center Univ. of North Dakota Grand Forks ND 58202 USA