Conducted joint field research for NASA's EO-1 Satellite Validation with forest researchers in Argentina (March, 2001).

    Conducted joint field research with researchers in Spain for validation of fuzzy classifier (February, 2001)

    Invited lecturer on modeling tree crown architecture at the Italian Academy of Forest Science (Accademia Italiana di Scienze Forestali) Firenze, Italy (November, 1998)

    Invited lecturer on forest modeling by the Chinese Academy of Forestry, Beijing (May, 1998)

    NATO research project on image processing using fuzzy logic  with researchers in Spain, and Italy (1996-1998).

    Invited lecturer on time series modeling of tree crown profiles at the Department of Mathematics, Complutense University, Madrid (April, 1996)

    Invited lecturer on remote sensing of natural resources at the Department of Mathematics, Complutense University, Madrid (December, 1996)

    Conducted joint biometrics research at the Niedersächsische Forstliche Versuchsanstalt (Forest Research Station of Lower Saxony) in Göttingen, Germany (Dec. 1995 - Jan. 1996)

    Advisor for five German graduate exchange students since 1990 from the Universities of Göttingen and Freiburg, Germany