At the beginning of his academic career he taught at the Ural Polytechnical Institute. He gave a great number of lecture courses during that period. His lectures were distinguished by the depth of content, high scientific level, and clarity of presentation. It is well known that he gave lectures and practical classes on a wide range of mathematical disciplines to students of the "golden class," who graduated from the Faculty of Physics and Technology in 1954 (that class gathered the best students from all the faculties of the Ural Polytechnical Institute when the Faculty of Physics and Technology was first opened). We should note that the curriculum of the Faculty of Physics and Technology, as concerns mathematical disciplines, was at that time as comprehensive as the university curriculum of the Faculty of Mathematics and Mechanics.

This is one more highly interesting and valuable monograph on stability, and more strictly on Lyapunov's direct method, its inversion, extensions and applications. The author is indeed one of the major and most original contributors to this general theory. The problems are constantly elucidated with clarity, the definitions are given in full and most proofs are dealt with completely unless they are standard and readily accessible - at least in the Russian literature. Not only is ordinary stability dealt with but also stability over a finite time interval - practical stability. Furthermore, constant attention is paid to the size of the domain of asymptotic stability - another practical consideration. For it stands to reason that if this domain is minute what takes place is practical instability. An extensive bibliography of 141 titles (11 non-Soviet titles) terminates the monograph.

This monograph is concerned with the modern development of optimal control theory and deals particularly with the case of linear and quasilinear systems, presently the most popular in practical applications. The author is himself a distinguished contributor to the theory of optimal control on the basis of his previous valuable results in the qualitative theory of differential equations and Lyapunov stability theory. The book presents a clear and exhaustive study of two fundamental problems: (1) to define the control parameters of a dynamical system with minimal "intensity'' and able to generate a prescribed motion; (2) to calculate the current variables of a moving dynamical system in view of an admissible change of a function of these variables along a motion. The problems are formulated in terms of linear and quasilinear ordinary differential equations.

... he initiated and encouraged applied studies and the development of the computer section of the Urals Scientific Centre (then the Urals Branch of the USSR Academy of Sciences, and later the USSR Academy of Sciences).

A more general concept of the positional differential game was then developed, theorems of the existence of the value of a game and of a saddle point were proved and constructive methods were proposed for generating optimal strategies. The key element was the so-called extremal shift of the real controlled object towards the ideal model, abstract or generated on a computer. The concept was extended to control problems under conditions of conflict and uncertainty of hereditary and stochastic systems, and also systems with degenerate higher derivatives.

Much of his time and energy is given to reporting on the progress of fundamental science to applied scientists, engineers, teachers, students and schoolchildren. In the 1980s he headed a campaign aiming to computerize schools and colleges in the Yekaterinburg region. This gave impetus to the subsequent raising of standards of schools in Yekaterinburg and the whole region to an adequate level of state-of-the-art information technology.

In his last years he was very anxious in preserving and improving the quality of higher and secondary education in his homeland. His daily activities in this sphere were of impressive variety and effectiveness, especially his lectures to school teachers and to high school students.

He was a fabulous lecturer and was very active and thorough in educational issues. ... Nikolai was a highly cultured man, whose interests ranged from literature, arts, and theatre to events in medicine and sports. His deep devotion to science, modesty and selflessness, with fairness and honesty definitely above personal interest are an everlasting example for our turbulent times.

... his pioneering ideas, which had been received by both theorists and practical engineers.