Oleg Vladimirovich Vasiliev (1939-2002) was a prominent scholar and educator of exceptional power of mind, who carried keen enthusiasm and veritable passion for mathematics through his entire career.
    Oleg Vasiliev was born in the Siberian city of Irkutsk on 1 November 1939 to the family of a professor of mathematics at the local university. His childhood coincided with the difficult years of the Second World War and the post-war deprivation. However, the regular lack of even basic necessities did not stop Oleg from developing a strong interest in sciences already in the early school years. This interest was always supported and welcomed by his father Vladimir Vasiliev, the founder of the Irkutsk scientific school on integro-differential equations.
    The thrust to knowledge led Oleg Vasiliev to the student bench at the Faculty of Physics and Mathematics of Irkutsk State University. Having written an excellent thesis devoted to dynamical systems, he graduated the university with summa cum laude diploma in 1962. It was just one year after the Soviet Union launched the first manned space flight, and Oleg Vasiliev gladly accepted the invitation to work as junior researcher at the Research Institute for Airspace Studies headed by the creator of Soviet cosmonautics Sergei Korolev. Yet, Vasiliev soon realized that the work in a secretive institution managed by the military imposes severe limits on the academic freedom and decided to leave the institute.
    During the new phase of his carrier, the academic interests of Oleg Vasiliev turned to the field of optimal control. He joined the group of scholars under the leadership of Professor Faina Kirillova, who became the main academic advisor of his PhD studies. After the successful defense of the PhD dissertation in 1966, Vasiliev returned to his alma mater, Irkutsk State University. He was immediately appointed the head of a newly created chair of Optimization Methods, and, then, at the age of 33, the Dean of the Faculty of Mathematics. Since 1972 and until his very last day, Oleg Vasiliev remained an unquestionable leader of the Faculty for both his colleagues and for many generations of students.

    A true partisan of Russian education and science, Vasiliev rejected attractive offers to work abroad and left the Faculty only once, in order to complete his post-doctoral dissertation. An outstanding lecturer and superb public speaker and debater, he was also a skilful administrator – a rare combination of academic might and the gift of organizer. Thanks to Vasiliev, the Faculty of Mathematics not only survived the dim period of the transition to market economy in Russia but also expanded into the Institute for Mathematics and Economics in 1999.
    Oleg Vasiliev made a number of important contributions to the field of optimal control. Firstly, he obtained original results with regard to optimality conditions of singular control for PDE dynamic systems. Later, this achievement allowed Vasiliev to formulate the basic theory of singular optimal controls for distributed parameter systems. Another series of his works was devoted to the construction of numerical algorithms for solving optimal control problems. Vasiliev introduced the concept of determinative inequality, which helps to determine the region of varying of the control function and justifies the convergence of the proposed methods so as they can be successfully used on computing devices. The third group of his works was dedicated to solving inverse problems of mathematical physics by optimal control methods. In particular, Vasiliev suggested a numerical method for solution of the inverse tsunami problem and analyzed the problem of thermo-conductivity reconstruction for metal rods.
    The four decades of an outstanding academic carrier of Oleg Vasiliev are reflected in more than 130 academic publications, among them four monographs and seven textbooks. He also actively supported able and dedicated young scholars and supervised 22 PhD students. Today, many of his former students are well-known established scientists who represent an internationally recognized research school on optimization methods founded by Oleg Vasiliev.  


    Vasiliev played an important role not only in the formation and preservation of the best traditions of the Russian mathematical education and research. As early as in 1976, he initiated academic and educational contacts with Mongolian mathematicians and put his sincere efforts to promote and expand the scope of cooperation in the 80s and 90s. He supervised doctoral studies of 7 Mongolian students. Nowadays, many of them are encountered among the Mongolian foremost scholars in the area of applied mathematics.
    He is indeed the founder of Mongolian optimization school.
    In 1992, the Mongolian government acknowledged the contribution of Oleg Vasiliev to Mongolian mathematical science by awarding the Russian mathematician the title of Honored Scientist of Mongolia.