1. Assistant Professor, Wind Science and Engineering Research Center, Department of Civil Engineering, Texas Tech University, Lubbock, TX 79409. E-mail: xinzhong.chen@coe.ttu.edu
2. Robert M. Moran Professor, Nathaz Modeling Laboratory, Dept. of Civil Engineering and Geological Sciences, Univ. of Notre Dame, Notre Dame, IN 46556. E-mail: kareem@nd.edu