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JOURNALS // Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy // Archive

Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy, 2025 Volume 12, Issue 1, Pages 48–63 (Mi vspua339)

MATHEMATICS

About the Kozinec algorithm

V. N. Malozemova, N. A. Solovyevab, G. Sh. Tamasyancd

a St. Petersburg State University, 7-9, Universitetskaya nab., St. Petersburg, 199034, Russian Federation
b St. Petersburg State University of Economics, 30/32, nab. kan. Griboedova, St. Petersburg, 191023, Russian Federation
c Institute of Problems of Mechanical Engineering of the Russian Academy of Sciences, 61, Bolshoi pr., V.O., St. Petersburg, 199178, Russian Federation
d Mozhaiskiy Space Military Academy, 13, Zhdanovskaya ul., St. Petersburg, 197082, Russian Federation

Abstract: In 1964 at the dawn of machine learning, B.N. Kozinec proposed a simple numerical method (algorithm) for solving the following extremal problem. "In $n$-dimensional Euclidean space, two finite sets $P_1$ and $P_2$ are given. It is assumed that the corresponding convex hulls $C_1$ and $C_2$ of these sets do not have common points. It is required to construct a hyperplane separating the sets $P_1$ and $P_2$, i. e. such a hyperplane that does not have common points with the sets $C_1$ and $C_2$ and, in addition, the sets $C_1$ and $C_2$ lie on opposite sides of this hyperplane. In fact, it is desirable, among all the hyperplanes separating the sets $P_1$ and $P_2$, to find a hyperplane whose distance to the set $P_1 \cup P_2$ has the maximum value. Obviously, such a hyperplane will be a hyperplane passing through the middle of the vector connecting any two nearest points of the sets $C_1$ and $C_2$, perpendicular to it". Later this problem was called the problem of hard SVM separation of two finite sets (SVM - abbreviation for Support Vector Machine). The Kozinec algorithm uses a natural geometric version of the optimality criterion for the problem under consideration. This article provides a detailed analysis of the Kozinec algorithm from a modern perspective. In particular, a correct proof of its convergence is given. A working scheme algorithm is proposed. Two examples are considered in which the effectiveness of the conceptual and working schemes is compared.

Keywords: machine learning, hard SVM-separation, Kozinec algorithm, MDM-algorithm, SMO-algorithm, clipped iterations.

UDC: 519.8

MSC: 90C90

Received: 10.04.2024
Revised: 25.08.2024
Accepted: 29.08.2024

DOI: 10.21638/spbu01.2025.104



© Steklov Math. Inst. of RAS, 2025