Affiliation: | (1) Department of Aeronautical Engineering, Korea Aviation Polytechnic College, 438 Egeum- dong,Sachon, 664-180 Kyungnam, Korea;(2) School of Mechanical Eng.,College of Eng., Kyungpook National University, 1370, Sankyuk- dong,Puk- ku Daegu, 702-701, Korea |