The controllability theory may at times lead to a control law as can be seen in the control theory literature. In this paper, a global control algorithm is proposed for nonlinear systems in the sc-called linear-analyt...
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The controllability theory may at times lead to a control law as can be seen in the control theory literature. In this paper, a global control algorithm is proposed for nonlinear systems in the sc-called linear-analytic form in the plane. The algorithm is motivated by a theorem by Hunt, which gives sufficient conditions for the global controllability of linear-analytic systems on a 2-dimensional manifold. It is verified that the algorithm is globally convergent under the given assumptions. A computational form of the algorithm is presented. Some computational aspects are also discussed.
For a series of the inverse complex problems of parameters restore for elliptic parabolic multicomponent distributed systems the computational algorithms are proposed for realization of gradient methods on the basis o...
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For a series of the inverse complex problems of parameters restore for elliptic parabolic multicomponent distributed systems the computational algorithms are proposed for realization of gradient methods on the basis of solution of direct and conjugate problems in weak formulations. The proposed approach eliminates the need for explicit constructing Lagrangian functionals and using Green functions.
An approach to discovering rules in nonstationary k-valued Multidimensional time series is proposed. It allows one to discover rules that are subject to "smooth" structural changes with the course of time. A...
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An approach to discovering rules in nonstationary k-valued Multidimensional time series is proposed. It allows one to discover rules that are subject to "smooth" structural changes with the course of time. A measure of rule similarity is proposed to describe such changes, and its application in the form of weight in the graph of rules is discussed. The discovered rules can be used to predict the next elements in the multidimensional time series, to analyze the phenomenon described by this multidimensional time series, and to model it. This allows one to use the proposed algorithm for predicting time series and for examining and describing the processes that can be represented by a multidimensional time series. Means for the direct practical application of the proposed methods of the analysis and prediction of time series are described, and the use of those methods for the short-range prediction of a real-life multidimensional time series consisting of the stock prices of companies operating in similar fields is discussed.
An algorithm for the automatic parallel generation of three-dimensional unstructured grids based on geometric domain decomposition is proposed. A software package based on this algorithm is described. Examples of gene...
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An algorithm for the automatic parallel generation of three-dimensional unstructured grids based on geometric domain decomposition is proposed. A software package based on this algorithm is described. Examples of generating meshes for some application problems on a multiprocessor computer are presented. It is shown that the parallel algorithm can significantly ( by a factor of several tens) reduce the mesh generation time. Moreover, it can easily generate meshes with as many as 5 x 10(7) elements, which can hardly be generated sequentially. Issues concerning the speedup and the improvement of the efficiency of the computations and of the quality of the resulting meshes are discussed.
The design of the patch antenna oriented for space application is a balanced solution between multiple disciplines. New disciplines are considered in these studies such as vibration and cost. To address the challenges...
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The design of the patch antenna oriented for space application is a balanced solution between multiple disciplines. New disciplines are considered in these studies such as vibration and cost. To address the challenges, a novel framework called Multidisciplinary Design Optimization is developed including problem definition, multidisciplinary modeling and a heuristic optimizer. The Gravitational Search algorithm is used to enhance the performance parameters of the proposed configuration. The performance parameters are computed at the resonating frequencies of the proposed antenna. Two polarized configurations in S-band are proposed: rectangular and circular. A proof-of-concept design example is the 2.4 GHz patch antenna using Rogers substrate material which has demonstrated the effectiveness of the proposed framework. The proposed antenna could be a successful choice for micro satellite applications.
The Zakai filtering is applied for tracking of nonlinear time-varying parameters on a physical model describing typical electrodeposition process that is fixed on the bulk solution boundary of diffusion layer and is o...
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This paper addresses the computational aspect of the extension principle when the principle is applied to algebraic mappings and, in particular, to weighted average operations in risk and decision analysis. A computat...
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This paper addresses the computational aspect of the extension principle when the principle is applied to algebraic mappings and, in particular, to weighted average operations in risk and decision analysis. A computational algorithm based on the α-cut representation of fuzzy sets and interval analysis is described. The method provides a discrete but exact solution to extended algebraic operations in a very efficient and simple manner. Examples are given to illustrate the method and its relation to other discrete methods and the exact approach by non-linear programming. The algorithm has been implemented in a computer program which can handle very general extended algebraic operations on fuzzy numbers.
The paper considers stages of the development of studies in computing optimization in Ukraine (in particular, at the V.M. Glushkov Institute of Cybernetics of the National Academy of Sciences of Ukraine) related to el...
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The paper considers stages of the development of studies in computing optimization in Ukraine (in particular, at the V.M. Glushkov Institute of Cybernetics of the National Academy of Sciences of Ukraine) related to elements of error theory, computational algorithms that are optimal in accuracy and time, high-tech computer technologies for solving problems in computational and applied mathematics with given values of quality characteristics.
The problem of determining the permittivity of material samples of arbitrary shape placed in a rectangular waveguide with perfectly conducting walls is investigated. The problem is reduced to solving a nonlinear volum...
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The problem of determining the permittivity of material samples of arbitrary shape placed in a rectangular waveguide with perfectly conducting walls is investigated. The problem is reduced to solving a nonlinear volume singular integral equation. A theorem on the existence and uniqueness of solutions to the nonlinear volume singular integral equation and of the inverse boundary value problem for determining the permittivity of the material is proved.
A new algorithm for determining the optical parameters of deposited multilayer optical coatings based on comparing the positions of the extrema of the optical characteristics of multilayer optical coatings is proposed...
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A new algorithm for determining the optical parameters of deposited multilayer optical coatings based on comparing the positions of the extrema of the optical characteristics of multilayer optical coatings is proposed. Two versions of this algorithm are compared. Using a series of numerical simulation experiments, the advantage of one of these versions is demonstrated. It is shown that this version decreases the influence of systematic errors in the spectral data.
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