1.       2019.08, Topic:   GNSS VRS positioning software in PoYang lake area, in Department of Earth Science of the Ohio State University, the USA

2.       2015.2.11， Topic: ZigBee indoor positioning method, in Department of Electrical Eng. of University of New Orleans, the USA

3.       2014.04， Topic: RSSI ranging model and 3D indoor positioning method（ZigBee Network）,  in Department of Geodesy of University of Warmia and Mazury at Olsztyn, Poland

4.       2012.08，Topic: mass center algorithm of ZigBee indoor positioning system and examples, in SPIN lab, the Dept. of Civil, Environmental Eng. and Geodetic Science of the Ohio State University, the USA

5.       2007.10， Topic: GPS/magnet integrated navigation system, in the Dept. of Geodesy and Geomatics Eng.  University of New Brunswick, Canada

6.       2002.04， Topic: Algorithms of GPS/INS integrated navigation system, in the Dept. of Civil, Environmental Eng. and Geodetic Science of the Ohio State University, the USA