Search

Studies the role of automatic control theory that lead to system methodologies of identification for various types of applied problems. System methodologies developed for the practical use of the mathematical apparatus of the theory; Orientation of research activity to realization and detailed description of the rational structure of identification within the framework of various search systems; Provision of the subject of identification with informational support for transformation of the difficult-to-formalize conditions.

In this paper, we solve the problem of detecting anomalies in X-ray images obtained by full-body scanners (FBSs). The paper describes the sequence and description of image preprocessing methods used to convert the original images obtained with an FBS to images with visually distinguishable anomalies. Examples of processed images are given. The first (preliminary) results of using a neural network for anomaly detection are shown. [ABSTRACT FROM AUTHOR]

The paper proposes a predictive approach to assessing special classes of dangerous states in the development of technological processes in order to make proactive decisions. The developed approach is based on a hybrid model based on the combination of an evidence-based classifier, fuzzy logic, and a Dempster–Shafer probabilistic scheme for evidence combination. The article presents a formal description of the predictor of critical states of the technological process. The resulting approach is universal and applicable in the automation of any complex technical systems. As an example, this article considers the application of the developed approach to solve the problem for assessing the safety of the technological process of shunting trains on a hump yard. The presented example shows the high efficiency and practical usefulness of the developed approach. [ABSTRACT FROM AUTHOR]

This paper considers the multi-depot vehicle routing problem with object alternation. We propose a formal statement of the problem with two types of objects and a mathematical model with two blocks of Boolean variables. First, the model is studied without gathering vehicles (mobile objects). Then, a special object (a single collection point) is introduced in the model. We show additional constraints of the mathematical model with this object. Special attention is paid to the condition of no subcycles. This condition is considered based on the adjacency matrix. Five greedy algorithms are proposed for solving the problem, two of which are iterative. One of the greedy algorithms is given a probabilistic modification based on the randomization of variables (an adaptive algorithm). Finally, the proposed algorithms are compared in terms of the average value of the objective function and the running time in a computational experiment. Also, the results of another experiment—the parametric tuning of the adaptive algorithm—are presented. [ABSTRACT FROM AUTHOR]

The paper deals with the construction of interpretable machine learning models. The approximation problem is solved for a set of shapes on a contour image. Assumptions that the shapes are second-order curves are introduced. When approximating the shapes, information about the type, location, and shape of curves as well as about the set of their possible transformations is used. Such information is called expert information, and the machine learning method based on expert information is called expert-augmented learning. It is assumed that the set of shapes is approximated by the set of local models. Each local model based on expert information approximates one shape on the contour image. To construct the models, it is proposed to map second-order curves into a feature space in which each local model is linear. Thus, second-order curves are approximated by a set of linear models. In a computational experiment, the problem of approximating an iris on a contour image is considered. [ABSTRACT FROM AUTHOR]

The paper considers the problem of visual odometry based on a sequence of video frames formed using a camera perpendicularly downward facing the reference surface. The problem is solved under the assumption that the shooting frequency is high, so that the interframe rotation and shift parameters are small. The technology is implemented in the form of a sequence of the following steps: determining the shift and rotation with an accuracy of an integer number of pixels using the correlation method, clarifying the shift and rotation parameters using the optical flow method, and correcting estimation errors associated with uneven motion and fluctuations in the distance of the camera to the reference surface by estimating deviations of local calibration characteristics from their mean values. The results of experimental studies of the technology on test trajectories obtained by simulating the motion of a vehicle along the reference surface are presented. [ABSTRACT FROM AUTHOR]

We study the implementation of the optimal control strategy obtained in [1] and supplemented in [2]. The algorithm for optimal stabilization of a linear stochastic differential system in a position determined by a piecewise constant Markov drift has been tested in a substantial number of model experiments. The drift value is observed indirectly; i.e., the control problem is solved in the statement with incomplete information. Practical implementation is complicated by the instability of Euler–Maruyama numerical schemes that implement the Wonham filter, which is a key element of the optimal control strategy. To perform calculations, the Wonham filter is approximated by stable schemes based on the optimal filtering of Markov chains by discretized observations [3]. These schemes have different implementation complexity and orders of accuracy. The paper presents a comparative analysis of the control performance for various stable approximations to the Wonham filter and its typical implementation using the Euler–Maruyama scheme. In addition, three versions of discretized filters are compared and final recommendations are given for their application in the problem of stabilizing a system with hopping drift. [ABSTRACT FROM AUTHOR]

The paper deals with the problem of triclustering in multivalued triadic contexts in terms of one multidimensional extension of formal concept analysis; triclustering can be viewed as a search for dense subtensors in three-dimensional tensors over the field of real numbers. Two methods are proposed for solving this problem, namely, NOAC—a version of the OAC triclustering method for numerical data based on delta operators—and a triadic version of the -means method with an improved metric based on Manhattan distance and proximity predicates in each of the three dimensions. Numerical experiments are carried out both on real and synthetic data and confirm the superiority of the NOAC method in terms of the performance criteria for the resulting triclusters. [ABSTRACT FROM AUTHOR]

We consider the problem of stabilizing a cart moving along a straight line with an inverted pendulum installed on it. The control objective is to stabilize the cart at a given target point so that the pendulum is in the upper vertical position. The main difficulty associated with solving this problem is that the two subsystems (the cart and the pendulum) must be stabilized simultaneously using one control. A new control law is proposed based on the introduction of a second-order reference system, the trajectory of which is taken as the target one for the cart with the pendulum. By extending the reference system to the fourth order and introducing an algebraic condition coupling the two systems, the target trajectory is found in the four-dimensional phase space of the original system and a control law is constructed that ensures the trajectory of the closed-loop system asymptotically approaching the target one. The control law obtained in this paper is applicable to systems with an arbitrary ratio of pendulum and cart masses, since the closed-loop system does not depend on the mass characteristics of the system. The range of the system parameters is found for which the linearized system is stable. The presentation is illustrated with numerical examples that demonstrate the efficiency of the proposed control. [ABSTRACT FROM AUTHOR]

The paper is based on using methods of continuous mathematics in discrete problems. Three new approaches to solving scheduling theory problems are considered, namely, a metric approach, an interpolation approach, and a combined one (metric interpolation). Metric interpolation is a mix of the other two approaches and combines their advantages. Each of these approaches permits one to reduce the time required for solving the corresponding problems and calculate the values of the guaranteed absolute error of the objective function. [ABSTRACT FROM AUTHOR]

We propose a dead-end control algorithm for the exact solution of NP-hard combinatorial optimization problems. The efficiency of the algorithm is demonstrated by examples of solving the set-partition and 0-1 knapsack problems. The paper also shows that the use of the idea of dead-end controls when implementing the dynamic programming method can considerably reduce the number of problem state variables at each optimization step. A comparative analysis of the proposed method with known algorithms for solving these problems is carried out. [ABSTRACT FROM AUTHOR]

In this paper, we consider the problem of determining politico-ideological preferences of users of online social networks. We propose a (DLS) model that allows assessing politico-ideological preferences of VKontakte users using information from their accounts (digital footprints). The model meets the main ideological directions in modern-day Russia. Our approach is based on the supervised learning methodology whereby one solves a classification problem by calculating posterior probabilities of class membership. We compile an anonymized labeled dataset and develop appropriate software. Then we formulate and solve the problem of the politician's choice of an ideological positioning strategy that will potentially receive the most support from the considered set of users. We exemplify our methodology by finding "ideal" political positioning for some popular online communities in VKontakte. [ABSTRACT FROM AUTHOR]

We consider a class of hyperbolic systems of linear inhomogeneous partial differential equations with one spatial variable. As a rule, in the case of systems of partial differential equations, when solving particular problems, additional conditions are immediately used to ensure the uniqueness of the solution. However, this greatly complicates the construction of a solution in the case of additional conditions of nonstandard form. For a similar situation in the case of ordinary differential equations, one tries to find a general solution, for which one can then try to use the given additional conditions. However, for systems of partial differential equations, this approach is difficult, since, as a rule, in this case it is not possible to construct the general solution. For the class of systems of linear inhomogeneous partial differential equations considered in the present paper, it was possible to find an algorithm for constructing a general solution. A distinctive feature of the considered systems of equations is the multiplicity of the corresponding characteristics. As an application of the proposed algorithm, a general solution of the Kolmogorov system of equations for the probabilities of the states of a process is obtained, which describes the behavior of a popular model of a stochastic system of the type -out-of- with a general distribution of the repair time for failing components. The indicated system of Kolmogorov equations is a system of partial differential equations of the mentioned class. Therefore, it is possible to construct a general solution for this system. [ABSTRACT FROM AUTHOR]

The paper presents a model for clustering homogeneous firms according to their operation efficiency over a certain time period. The firm efficiency is studied by the Data Envelopment Analysis (DEA) methodology, which is based on solving optimization problems and permits one to compare firms taking into account many factors of their operation. At the second step of the analysis, the time series of firm efficiency estimators obtained by DEA modeling are used to cluster firms and find stable partitions of the set of firms. [ABSTRACT FROM AUTHOR]

In this paper, design problems are considered for bilinear control systems subjected to arbitrary-but-bounded exogenous disturbances and containing structured matrix uncertainty. We formulate and solve the problem of efficient construction of robust stabilizability ellipsoids and the domain of robust stabilizability of bilinear systems, both in continuous and discrete time; the basic tool is the linear matrix inequality technique. [ABSTRACT FROM AUTHOR]

An optimal control problem for the string vibration equation with given initial and terminal conditions, nonseparated states at intermediate instants and a performance criterion defined on the entire time interval is considered. This problem is solved using the methods of separation of variables and the theory of optimal control of finite-dimensional systems with nonseparated multipoint intermediate conditions. As an illustrative example of the approach proposed in the paper, an optimal control of string vibrations with given nonlocal deflection values of the string at some intermediate instants is constructed. [ABSTRACT FROM AUTHOR]

This paper proposes a dynamic game-theoretic statement of the resource allocation problem in an organizational system. The application of evolutionary modeling algorithms for solving such problems is considered. Some illustrative examples are given. [ABSTRACT FROM AUTHOR]

This paper suggests an estimation procedure for the analytical complexity and errors of solving control problems for organizational and technical systems using uniform search. It is demonstrated that, first, attempts to reduce errors cause complexity rise; second, complexity goes down as the number of levels in a control hierarchy is increased (under decomposition of control problems); and third, errors and complexity are natural restrictors for the growth of organizational hierarchies and application of complex control mechanisms as well as stimulate the choice of typical solutions (patterns). [ABSTRACT FROM AUTHOR]

Proposed was a method to solve control problems for the nonstationary heterogeneous linear systems under conditions on the state and control functions at different time points. It consists of a phased transition from of the initial problem to the formula for the determination of some part of the functions of control and a problem similar to the previous one for a system with a smaller number of equations. The suggested method is a modification of the previous method of cascade decomposition, which solves problems using the projectors on the subspace. In the present paper, decomposition was carried out by solving the linear algebraic equations and replacing linearly the desired vector functions. The procedure of differentiation of certain functions was used to construct the controlled process. [ABSTRACT FROM AUTHOR]

This paper presents the statement and solution to the problem of synthesis of the anisotropic control that guarantees some prescribed level of attenuation of the uncertain stochastic disturbances affecting the linear discrete time-varying system on finite time horizon. The anisotropy of a random vector is considered as a measure of the statistical uncertainty of the disturbance. The closed-loop system capabilities to attenuate the external disturbances are characterized by its anisotropic norm. The synthesis problem solution is formulated in form of sufficient conditions of existence of a controller that guarantees the anisotropic norm of the closed-loop system to be bounded by some given threshold level. The controller synthesis algorithm is based on solving the system of matrix inequalities recursively. [ABSTRACT FROM AUTHOR]

The analysis of asymptotic stability of nonlinear oscillator is one of the classical problems in the theory of oscillations. Usually, it is solved by exploiting Lyapunov functions having the meaning of the full energy of the system. However, the Barbashin-Krasovskii theorem has to be used along this way, and no estimates can be found for the rate of convergence of the trajectories to equilibria points. In this paper we propose a different Lyapunov function which lacks transparent physical meaning. With this function, both the rate of convergence and the domain of attraction of equilibria points can be estimated. This result also enables an efficient analysis of another problem, synchronization of oscillations of two oscillators. We formulate conditions that guarantee frequency synchronization and, on top of that, phase synchronization. Generalizations to the case of arbitrary number of oscillators are also discussed; solution of this problem is crucial in the analysis of power systems. [ABSTRACT FROM AUTHOR]

This paper formulates and solves the mob excitation control problem in the discretetime setting by introducing an appropriate number of 'provokers' at each step of control. [ABSTRACT FROM AUTHOR]

A method for evaluating carbon oxide concentration in high-temperature combustion processes is presented. The paper offers an optimizing control problem for fuel combustion process using a stabilizing regulatory controller, which affects the fuel/air ratio with respect to carbon oxide concentration in the firebox. In this connection, an approach is offered to solving this problem subject to the correction factor compensating for the error of carbon oxide concentration measurement. [ABSTRACT FROM AUTHOR]

Consideration was given to the problem of suboptimal control of the flight vehicle in atmosphere which was solved numerically. The results presented corroborate the efficiency of this procedure. The present paper is distinguished for the fact that the complex nonlinear boundary problem was solved using a finite number of arithmetic operations. [ABSTRACT FROM AUTHOR]

This paper studies generalized solutions of boundary-value problems for parabolic and hyperbolic equations on an arbitrary geometrical graph. Finally, the one-valued solvability conditions are established for these problems. [ABSTRACT FROM AUTHOR]

This paper studies the resource allocation problem based on agents’ opinions with possible delegation. In other words, any agent can report just some components of the allocation vector as his request. We describe symmetrical anonymous generalized median voter schemes supplemented with delegation procedures; they can be applied for solving the posed problem. [ABSTRACT FROM AUTHOR]

This paper considers construction algorithms for the topological 2-D drawing of a graph. These algorithms allow to store, describe and modify the existing information on the drawing of a graph. Finally, we introduce necessary notions and structures to solve the problem of the topological 2-D drawing of a graph. [ABSTRACT FROM AUTHOR]

In this paper we propose a model for taking into account International Monetary Fund (IMF) mebers’ preferences to coalesce based on joint membership in political end economic organizations beyond the IMF and on regional proximity. The analysis of members’ effective power is carried out on the base of developed power indices for three variations of decision making thresholds implemented in the Fund. [ABSTRACT FROM AUTHOR]

Consideration was given to derivation of the motion equations of a space robotic module with a mathematical model having many degrees of freedom whose number can vary in the course of operation. This problem was solved in a computing environment such as the Maple program package. It was anticipated that the on-line mathematical model would be used to establish a rational in a sense motion control law of such a complicated object. For this purpose the paper solved some problems of decomposition of the resulting mathematical model. The results of computer-aided derivation of the motion equations of several particular schemes of the of the space robotic module were presented to illustrate constructiveness of the proposed mathematical support of problem solution. [ABSTRACT FROM AUTHOR]

The concept of a risk-guaranteed solution for many-criteria problems under uncertainty, which is typical of emergency situations, and a solution algorithm for these problems are described in Part I of this paper. In Part II, this algorithm is realized for a two-criteria problem under bounded uncertainties and linear-quadratic criteria. [ABSTRACT FROM AUTHOR]