To Deeply Cherish the Memory of Da Ruan, My Friend since 1988
Da Ruan passed away suddenly, left us not only with the enormous sadness and shock but also the endless recollections of the past.
I was sent to Belgium by Shanxi provincial government as a visiting scholar in 1988. Considering my research area is related to mathematics of fuzziness, in 1991 I contacted Professor Etienne Kerre from Ghent University for cooperation and his guidance and was finally accepted by him. In the follow-up communications with Etienne, I heard of Dr. Da Ruan for the first time (he has obtained the PhD degree from Ghent University). I got in touch with Da soon who told me much information about Belgium and the life abroad. From Da, I also obtained some help and encouragement which have been much important for my starting of research and life in Belgium. I arrived at Ghent University on Nov. 17, 1993 and started my study and research life as well as the face to face contact with Da since then.