1. Research Centre for Astronomy and Earth SciencesGeodetic and Geophysical Institute, Hungarian Academy of Sciences Sopron Hungary
2. Doctoral School of Enviromental SciencesUniversity of Szeged Szeged Hungary
3. Parsons LaboratoryMassachusetts Institute of Technology Cambridge Massachusetts USA
4. Department of PhysicsTripura University Agartala India
5. Institute of Information Science and EngineeringHarbin Institute of Technology Weihai China