REVUE D'ANALYSE NUMÉRIQUE ET DE THÉORIE DE L'APPROXIMATION

This article is dedicated to the well known approximation specialist Professor Dr. Dimitrie D. Stancu, on the occasion of the 80th anniversary of this birthday.

He was born on February 11, 1927, in a very poor farmer family from the village Călacea, situated not far from Timişoara, the capital of Banat, which is a province of Romania, in the south-west part of this country. Because they were very poor and he remained orphan, he was forced to work as shepherd engaged by a rich family. Consequently he was able to go to primary school only when he was 9 years old. His oldest brother worked in a painter workshop in Arad city and he came in 1937 to take him in Arad at the "Regina Maria" orphanage, where there was included also an elementary school. In 1943 he entered at the Gymnasium from the district "New Arad". In the period 19431947 he studied at the prestigious Lyceum "Moise Nicoară" from Arad. In 1947 he began a four-year study at the "Victor Babeş" University from Cluj, the capital of the Romanian province "Transylvania".

During his studies he was under the influence of professor Tiberiu Popoviciu (1906-1975), a great master of Numerical Analysis and Approximation Theory, who has stimulated him to do research work in mathematics. In 1951, after his graduation, he was named assistant at the Department of Mathematical Analysis, University of Cluj. He obtained the Ph.D. in mathematics in 1956. His scientific advisor for the doctoral dissertation was professor Tiberiu Popoviciu.

In a normal succession he advanced up to the rank of full professor in 1969.
Professor D. D. Stancu was happy to benefit an excellent opportunity to get a fellowship at the Numerical Analysis Department, University of Wisconsin, Madison, conducted by late professor Preston C. Hammer. He spent at this university the academic year 1961-1962.

In October 1963, in time of President John Fitzgerald Kennedy (who was assassinated, after one month, in Dallas, Texas), he has participated, on the base of an official invitation from the Society for Industrial and Applied Mathematics (SIAM), at a "SIAM Symposium on Approximation" organized in Gatlinburg, Tennessee (October 21-26, 1963), where he has given a talk, which was published in the Journal SIAM Numer. Anal., Ser B, vol. 1 (1964), pp. 137-162.

Professor D. D. Stancu has participated at different events in USA, organized by the American Mathematical Society. He has presented contributed papers at several regional meetings of this Society from: Milwaukee, Chicago and New York.

Returning from America, he was named deputy dean at the Faculty of Mathematics of "Victor Babes" University from Cluj, as well as chief of the chair of Numerical and Statistical Calculus.

He has a nice family. His wife, dr. Felicia Stancu, was a lecturer of Mathematics at the same university from Cluj-Napoca. They have two wonderful daughters: Angela (1957) and Mirela (1958), both teaching now mathematics in secondary schools in Cluj-Napoca. From them they have three grandchildren: Alexandru-Mircea Scridon (1983) and George Scridon (1992) (the sons of Mirela) and Ştefana Muntean (1991) (the daughter of Angela). Their oldest grandson Alexandru-Mircea Scridon, graduated the Romanian-German section of Informatics at the University of Cluj. Didi Stancu loves them all deeply and warmly.

Professor Stancu has taught several courses at his University: Mathematical Analysis, Numerical Analysis, Approximation Theory, Informatics, Probability Theory and Mathematical Statistics, as well as Constructive Theory of Functions.

In his research papers he has used interpolation probabilistic, spline and umbral calculus for the construction of approximation operators. He studied also quadrature and cubature formulae in the case of functions of one and several variables.

He had a large numbers of doctoral students from Romania, Germany and Vietnam.

Professor Stancu has participated at many international scientific meetings of mathematics, organized in Romania (Cluj, Bucharest, Iaşi, Timişoara), Germany (Stuttgart, Hannover, Hamburg, Goettingen, Dortmund, Münster, Siegen, Berlin, Würzburg and Oberwolfach), Italy (Roma, Napoli and Potenza), England (Lancaster and Durham), Hungary (Budapest), France (Paris), Bulgaria (Sofia and Varna), Poland (Warsaw), Czech Republic (Brno) and USA (Nashville, S.C.-Columbus, OH, Columbia, S.C.).

There are more than 60 papers published in different mathematical journals, containing in their titles the name of D. D. Stancu.

Since 1961 he is a member of the American Mathematical Society and a reviewer of the international journal "Mathematical Reviews".

He is also a member of the German society: "Gesellschaft für Angewandte Mathematick und Mechanik" as well as a reviewer of the international journal "Zentralblatt für Mathematik".

In Romania he is the Editor in Chief of the journal published by the Romanian Academy: "Revue d'Analyse Numérique et de Théorie de l'Approximation".

Many years ago he became a member of the Editorial Board of the Italian mathematical journal "Calcolo", published now by "Springer-Verlag", in Berlin.

In 1996 Professor D. D. Stancu has organized at the University "BabeşBolyai", Cluj-Napoca, an "International Conference on Approximation and Optimization", in conjunction with the Second European Congress of Mathematics, held in Budapest, where participated around 150 mathematicians from 20 countries around the world. The Proceedings of this ICAOR conference were published in two volumes, having the title: "Approximation and Optimization", by Transilvania Press, Cluj-Napoca, Romania, in 1997.

In 1995 the "Lucian Blaga" University from Sibiu, has awarded him the scientific title of Doctor Honoris Causa. Few years ago the "North University" of Baia Mare, from which he had several doctoral students, has distinguished him with the same title.

In 1999 professor D. D. Stancu was elected as Honorary Member of the Romanian Academy.

In the same year he has participated with an invited lecture at the "Alexits Memorial Conference" in Budapest.

In May 2000 he was invited to participate at the International Symposium "Trends in Approximation Theory" dedicated the 60th birthday of Professor L. L. Schumaker, held in Nashville, Texas, where he presented a paper in collaboration with professor Wanzer Drane, from Columbia, S.C.

In May 9-11, 2002, there was organized by "Babes-Bolyai" University, ClujNapoca, the "International Symposium on Numerical Analysis and Approximation Theory", dedicated to the 75th anniversary of Professor D. D. Stancu. The Proceedings of this Symposium was edited by Radu T. Trâmbiţas and published in 2002 by "Cluj-Napoca University Press" ( 476 pages).

In the period 5-8 July, 2006 there was organized in Cluj-Napoca an "International Conference on Numerical Analysis and Approximation Theory". Professor D. D. Stancu was an honorary chair of this Conference. The Proceedings of this International Conference were edited by professors Octavian Agratini and Petru Blaga, and published by "Casa Cărţii de Stiinţă", ClujNapoca, 2006 (418 pages).

Editing this article we can state that the intensive work and his important results obtained in Numerical Analysis, Approximation Theory and Probability Theory has brought him recognition and appreciation in this country and abroad.

We conclude by wishing to Didi Stancu many fruitful and happy years, with health and happiness.

Professor dr. GH. COMAN
Faculty of Mathematics and Informatics
"Babeş-Bolyai" University
Cluj-Napoca, Romania
e-mail: ghcoman@math.ubbcluj.ro

Professor dr. I. PǍVĂLOIU
"T. Popoviciu" Institute of Numerical Analysis
Romanian Academy
Cluj-Napoca, Romania
e-mail: pavaloiu@ictp.acad.ro

February 11, 2007.