1. School of Civil Engineering, Hunan City Univ., Yiyang, China; Dept. of Mechanical Engineering, Univ. of Houston, Houston, TX.
2. School of Civil Engineering, Changsha Univ. of Science and Technology, Changsha, China.
3. Hunan Provincial Communications Planning, Survey and Design Institute Company Limited, Changsha, China.
4. School of Civil Engineering, Hunan City Univ., Yiyang, China; Dept. of Mechanical Engineering, Univ. of Houston, Houston, TX