On December 10, 2017, Stepan Dmitrovich Ivasishen, a well-known mathematician, a talented teacher, a professor, a head of the Department of Mathematical Physics of the FPM, an academician of the Higher Education Academy of Sciences of Ukraine and a Doctor of Physical and Mathematical Sciences, turned 80. In 1959, Stepan Dmitrovich graduated from the Chernivtsi University (CNU) with a diploma with honors, studied in the graduate school, and after defending his PhD thesis, his exemplary lectures for students and teachers become known throughout the university. At the age of 25 he is elected the youngest at the university by the head of the department of differential equations. His lectures that are optimized at the highest scientific and pedagogical level on mathematical disciplines cause admiration among students and teachers. The lectures are visited by students, scientists and teachers of other departments and other universities, and his highly professional work is highly appreciated - his surname with a portrait is taken to the regional Honors Board downtown.
In 1969, Stepan Dmitrovich is invited to head the department of higher mathematics at the leading at that moment Kyiv Higher Engineering Radio Technical Specialized School of Air Defense, where his new scientific and pedagogical achievements are marked by many awards of the specialized school and state awards - the Order of the Red Banner of Labor and the medal "For Valiant Labor". In 1981, he moved to the Department of Mathematical Analysis of Taras Shevchenko Kyiv University and subsequently successfully defended his doctoral thesis "The Green Matrices of Parabolic Boundary Problems".
Since 1988, Stepan Dmitrovich has been leading coordinated scientific research in the Western Scientific Center of the National Academy of Sciences of Ukraine and the Ministry of Education and Science of Ukraine. For this purpose he simultaneously creates and leads a department of boundary-value problems for partial differential equations at the Y.S. Pidstryhach NAS of Ukraine Institute of Applied Problems in Mechanics and Mathematics and the Department of Mathematical Modeling for the preparation of students-mathematicians of the research and production profile. During this period, his great abilities in organizing fruitful cooperation between the scientific departments of the National Academy of Sciences of Ukraine and the mathematical departments of the university are revealed. He takes an active part in the creation of postgraduate studies and specialized academic councils in getting candidate and doctoral theses. Under his leadership the issues of scientific papers collections "Mathematics" in the Scientific Bulletin of the CNU are regularly published. In October 2013, the all-Ukrainian scientific publication "Bukovinsky Mathematical Magazine" becomes its successor. The well-known regular scientific seminars are visited by scientists from many republics and abroad and he becomes an active member of the mathematics section bureau and mathematical modeling in the Western Scientific Center of NAS and MES of Ukraine. In September 2004, Stepan Dmitrovich accepted the invitation of academician I.V. Skripnik to work as a professor at the Department of Mathematical Physics of the KPI, and since 2005 he has been acting as the head of this department.
His fundamental results in the parabolic equations theory development, published by the prestigious international publishing house "Birkhauser" (Boston, Berlin, 2004), become known to the mathematical world in his monographs "Analytic methods in the theory of differential and pseudo-differential equations of parabolic type" and "The Green matrices of parabolic boundary-value problems" with the most accurate analytic results on the properties of fundamental solutions of various classes in parabolic equations, Green matrices of general parabolic boundary-value problems, and the correct solvability of the Cauchy problem and boundary-value problems, which are an important contribution to the treasury of Ukrainian and world science. At this time, Stepan Dmitrovich also conducts a large scientific and organizational work, including the examination of scientific works in the expert councils of the Higher Certification Commission of Ukraine and specialized academic councils, in the editorial boards of six professional scientific publications, in the organizational and program committees of many international scientific conferences with his plenary reports. He is a member of the Ukrainian and American Mathematical Societies, an academician of the Academy of Sciences of Ukraine. He was awarded the "Excellent Worker of Education of Ukraine", he also has the awards of Yaroslav the Wise and St. Volodimir in the field of science and technology of the Higher Education Academy of Sciences of Ukraine. He is the author of more than 350 publications, and his well-known teaching aids are used in the educational process at many universities in Ukraine.
Stepan Dmitrovich is extremely hard-working, self-demanding and accurate in his work. He is an example of a highly professional scientist-teacher who enjoys great authority among the world's mathematicians and colleagues at work. Today, full of strength and energy to set and solve new scientific tasks and problems, Stepan Dmitrovich passes the leadership of the department headed by him to younger students with the aim of further concentrating his efforts on the successful development of scientific research in his scientific school which is known to the mathematical world.
Dear Stepan Dmitrovich! We are proud of you! We congratulate you on the glorious jubilee and wish you strong health, new scientific achievements, family happiness and long years of our further cooperation for the sake of peace and prosperity of our native Ukraine!