1. 1 Department of Applied Mathematics , Virginia Military Institute (VMI) , Mallory Hall, Lexington, VA , U.S.A
2. 2 Department of Mathematics & Centre for Research and Development , KPR Institute of Engineering and Technology , Coimbatore, TamilNadu , INDIA
3. 3 Department of Mathematics , KSR College of Technology , Tiruchengode, TamilNadu , INDIA