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 Выпуск 85
- Bril D. A system of public administration: history of development of theory and improvement of practice of efficiency management of executive bodies of state power of the russian federation
In order to organize the implementation of domestic and foreign policy of the Russian Federation, to regulate the socio-economic sphere, to ensure the unity of the Executive power system in the Russian Federation, to direct and control the activities of its bodies, to form state programs and ensure their implementation, as well as to exercise the right of legislative initiative, how can we approach the creation and ensuring the effective work of Federal Executive bodies? To date, the legal framework for organizing the work of ministries and departments has been defined. At the same time, it has not yet been established how to carry out this activity in practice, and what methodologies to apply. Based on the practical experience of creating and implementing projects to improve the activities of two Federal services, a Federal Agency and a Federal state institution, the author describes the history of developing the theory and improving the practice of efficiency management of Executive authorities of the Russian Federation, and identifies problems that should be studied and resolved in order to implement reforms that improve the effectiveness of the implementation of their powers. The principles and approaches to the organization of the work have become the basis of the ongoing scientific research, including the acquisition of knowledge and its development within a specific specialty-Economics and management of the national economy.
- Gorbunova A., Lebedev A. Stochastic nontransitivity effects in queueing systems
The paper continues a series of articles devoted to the nontransitivity of the stochastic precedence relation for triplets of independent random variables. Initially, this problem was posed in connection with the application in strength theory. With paired comparisons of iron bars from three factories, a paradoxical situation may arise that the bars from the first factory are "worse" than the bars from the second factory, the bars from the second factory are "worse" than the bars from the third factory, and the bars from the third factory are "worse" than the bars from the first factory. Further, the nontransitivity topic gained popularity for the example of the so-called nontransitive dice. In previous works of the cycle, on the one hand, it was proved that there can be no nontransitivity for many classical continuous distributions, on the other hand, examples of nontransitivity for distributions with polynomial density on a unit interval, as well as for mixtures of normal and exponential distributions of at most than two components. In this paper, we open the topic of the possible influence of nontransitivity on the behavior of stochastic systems. Namely, we study how the nontransitivity of service times relation in the three single-server queueing systems affects the sojourn times, and how in the infinite-server queueing systems it affects the maximum residual service times. The study uses the classic nontransitive triplet of random variables with the same means and variances. In the first case, simulation modeling is used; in the second case, the analytical approach is used.
- Gubanov D. Influence in social networks: formalization variants
This paper suggests a generalization of previously proposed cases of formalizing the influence of users in online social networks based on the actional model of influence. We consider a number of questions, depending on the answer to each of which the notion of agent's influence should be formalized in slightly different ways: whether all the agent's actions have an impact or only the initial ones; whether the Principal (a control subject) is interested in the impact on the agent’s actions or the impact on the consequences of the agent’s actions; whether the Principal believes that the maximum possible influence on any agent takes the same value or not. We consider various combinations of answers to these questions and provide appropriate variants to formalize the notion of influence. We study the properties of the proposed variants of influence formalization (in particular, monotonicity and additivity of the influence function). Then we give examples of calculating the influence of users of the online social network Reddit and compare different variants of influence formalization.
- Rykov V., Filimonov A. Hyperbolic systems with multiple characteristic and applications
The article considers a certain class of hyperbolic systems of linear partial differential equations with one spatial variable. As a rule, in the case of systems of partial differential equations, when solving problems, additional conditions are immediately used that ensure the uniqueness of the problem. However, this greatly complicates the construction of the solution in the case of additional conditions of a non-standard form. For a similar situation, in the case of ordinary differential equations, they try to find a general solution, for which you 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 a general solution. For the class of systems of linear inhomogeneous partial differential equations considered in the article, we managed 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 that describes the behavior of the popular in applications of a model of a stochastic system of type k-fromn: F with a common distribution of repair time of failed components. The specified system of Kolmogorov equations is a system of differential equations in partial derivatives of the mentioned class. Therefore, for her it is possible to build a common solution.
- Shevlyakov A. Automatic differentiation in control of constrained rigid-body systems
Currently, many new types of robotic chassis are being developed. These require new approaches to modeling and control, satisfying many hard constraints on performance and quality. The research may be more focused on bipedal and quadrupedal locomotion at the moment, but groups of simple robots are studied as well. In this article, we consider a system of 2 cube robots as a mechanical constrained rigid body system. We use optimization to construct trajectories and find control. Unlike many previous methods, we explore the possibility of differentiating a target function by control variables. This is achieved by using automatic differentiation techniques. We give a brief survey of automatic differentiation, and also of reinforced learning, in the context of which it is now mostly developed. Also, basics of rigid body mechanics are presented, along with most important details of optimization algorithm. We consider several scenarios of robot configurations and goal positions, for which we find control and trajectories. Optimization parameters and hardware characteristics for the numerical experiment are provided. Results are presented as plots and frame sequences.
- Kokunko J., Krasnova S. Two approaches to invariant tracking system design for an unmanned aircraft vehicle
The problem of automatic control of the movement of the center of mass of an unmanned aircraft under the influence of external uncontrolled disturbances and measurements of only the spatial coordinates of the center of mass and their given trajectories is considered. The task is to synthesize of the control law in the form of dynamic feedback, providing tracking of the given signals invariant in relation to external disturbances with a given accuracy. Within the framework of the block approach with the use of sigmoidal feedback, providing the limits of fictitious and true controls, regulators of two types are developed. In the first controller, thanks to compensation of cross-links in the closed system the independent control of spatial coordinates of the center of mass with an independent choice of feedback parameters in each of the three loops is provided. To implement this algorithm, reduced order observer is constructed to estimate the velocity vector by measuring the center of mass vector coordinates. Based on these signals in online mode, the sinuses and cosines of angles of inclination of the trajectory and course are calculated in online mode, which are necessary for the formation of feedback. In the second controller, to reduce the amount of calculations performed in real time, the cross-connections are not compensated, and in a closed system the matrix before the control is not diagonal. In order to select the feedback parameters, a hierarchical procedure has been developed with the matrix form before control conversion to an offline upper triangular. To implement this algorithm, reduced order observer was constructed to estimate the vector of derivative tracking errors by measuring the tracking error vector. The results of numerical modeling and joint analysis of the developed regulators are given.
- Malsagov M., Merkulova M., Ougolnitsky G. Cooperative differential game theoretic models of innovations control
Creation and use of innovations determine a mainstream of the sustainable development of organizations of any type and are a necessary condition of the economic growth. In this paper we consider the problems of incentives of the employees for promotion of innovations by means of their reward allocation. The problems are formalized as cooperative differential games. In building of such games we used three different characteristic function: the classical Neumann-Morgenstern function as well as the functions proposed by Petrosyan and Zaccour, and Petrosyan and Gromova. The first function is always superadditive but is based on a not very realistic hypothesis of antagonism between a coalition and its complement. The second function more adequately used the players' payoffs in a Nash equilibrium but cannot guarantee the superadditivity. The third characteristic function provides a superadditive trade-off by guaranteeing the maximal payoff of a coalition when its members use their cooperative strategies. In all three cases the Shapley value is used as the optimality principle. Its components are calculated analytically and numerically by means of the Maple package. A comparative analysis of the results is made for a model example with three players for different values of the model parameters. The conclusions about the efficiency of the described methods of reward allocations are made.
- Akinfiev V. Modeling of the global oil market: research and results
The article analyzes the problems of modeling and forecasting the world oil market, and also provides an overview of approaches and models in this area. The main stages of development of the world oil market are presented and the events that led to structural changes in the behavior of oil prices are analyzed. The key factors affecting the formation of oil prices are presented, and their relationship is examined. One of the popular applications of mathematical models for forecasting the global oil market, which is considered in the article, is the use of econometric analysis methods, including VAR structural models. Another interesting area is related to the use of games and behavioral models. Widely used models of market equilibrium analysis considering various market structures based on MPEC models. Of considerable practical interest are also methods that combine game models, methods of multi-agent modeling, and modeling based on expert information. The analysis presented in the work shows that in many cases the use of mathematical models for forecasting the world oil market is useful, it allows you to get closer to understanding the mechanisms of its functioning and the relationship of its parameters. However, they still cannot fully cope with the problem of forecasting the world oil market.
- Novikov D. Dynamics models of mental and behavioral components of activity in collective decision-making
A model of collective decision-making is considered, in which the interconnected parameters reflect both the mental and behavioral components of the agents' activity: they study the mutually affecting processes of the dynamics of their states and actions, as well as the properties of the corresponding equilibria. Special cases are well-known models: active expertize, information management, threshold and conformal behavior. The proposed approach allows modeling such effects known in social psychology as: cognitive dissonance, hindsight, etc.
- Veresnikov G. Optimization models for parametric synthesis of design solutions under uncertain parameters
Epistemic uncertainty may typically occur at preliminary stages of the technical objects design due to necessity to establish design solutions using the expertise data. To model the epistemic uncertainty occurring upon receipt of information on the parameters of the technical object under design from the experts, B.Liu’s uncertainty approach was chosen, as it offered analytical forms to calculate the functions number characteristics depending on parameters with epistemic uncertainty, that provides high computation efficiency when making optimization calculations. The article offers optimization models developed within the frameworks of uncertainty approach to solve the tasks of design solutions parametric synthesis in preliminary design of the technical objects. These models include optimization criteria ensuring safety and robustness of the design solutions. To apply the optimization models developed, the analytical forms of number characteristics of the target functions and limitations depending on uncertain inputs and parameters under optimization. Use of such analytical forms provides a solution of uncertainty of parameters under optimization due to the need to take into account the tolerances in production without statistic data and due to iteration nature of complex technical objects design processes, where the parameters under optimization may be adjusted.
- Vorochaeva L., Savin S. Investigation of operation of links length control system of the crawling robot
The work is devoted to the development of a control system for the movement of a crawling robot when it moves on a horizontal rough surface. This system is a three-level and consists of the following units: gait control, formation of setting influences and control links. The greatest attention is paid to the system of formation of the setting influences, namely the system of correction of lengths of links of the robot entering into it and formation of laws of change of angles of their rotation. Correction of the length of the links may be necessary for the implementation of certain movements, for example, changing the configuration of the device when fixing on the surface of the two extreme supports, which is considered in this work. A sequential three-stage correction algorithm is proposed, in which the length of the central link first varies, then one of the side links and only then the second side link. Each subsequent stage is carried out only if the previous one is insufficient to prevent the robot from falling into special positions, in which there is a loss of all degrees of mobility. The proposed control system structure is built in such a way that, on the one hand, to determine directly the influence of the geometric parameters of the robot to the nature of the resulting motion, and to ease the algorithmic and software implementation of the proposed control law, allowing to implement a control system for extremely simple calculators. The adequacy of the developed control system has been verified by numerical simulation of the robot's motion and charting the correction options depending on the permissible values of elongation / shortening of the links and the initial and final configurations of the object.
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