Математика, механика, информатика. Рубрика в журнале - Сибирский аэрокосмический журнал
An analysis of intelligent methods and algorithms for unlabeled data processing
Статья научная
Intelligent algorithms and method is well-suited to many problems in data processing, where unlabeled data may be abundant. We survey previously used selection strategies for intelligent model, and propose two novel algorithms to address their shortcomings, focus on Active Learning (AL). While has already been shown to markedly reduce the annotation efforts for many sequence labeling tasks compared to random selection, AL remains unconcerned about the internal structure of the selected sequences (typically, sentences). We propose a semi-supervised AL approach for sequence labeling.
Бесплатно
An automatic device for measuring resistivity of the silicon four-point probe method
Статья научная
An automatic device for measuring the resistivity of single-crystalline silicon by means of the four-point probe method has been developed.
Бесплатно
Статья научная
The strict hierarchical manpower system is modeled in the state space where the desired number of men in particular rank is determined by predefined trajectory function. The transition model is represented by the principles of System Dynamics where each rank is represented as the state element and transition as the flow. The basis for the model is the structure of the exponential delay chain with additional outflows from particular states. The strategy for achieving the desired states is determined by the application of the genetic algorithms which are implemented in JavaScript as well as the System Dynamics model. Parameter boundaries were taken into consideration which was determined according to the historical data. Predetermination of the desired system states by the set of exponential functions reduced the optimization burden. The optimization problem was defined as the minimization of the sum of quadratic difference between desired and actual states in all ranks for the observed time horizon. Time boundaries in considered optimization problem were not constant which contributes to the complexity of the addressed optimization task. The six state finite automaton code realization is described which prevents the oscillations in the strategies. The algorithm for integration of system dynamics model and genetic algorithm with finite automaton is described.
Бесплатно
Статья научная
The structure of the invariant echo-jack of the second order without a protective time interval is synthesized. Control elements of such echo-jack are given. The calculation of the basic technical characteristics is presented.
Бесплатно
Automatic linear differential equation identification in analytical form
Статья научная
In this paper we suggest a reduction of linear dynamics identification problem to the global optimization task. The current approach allows automatic determining the structure and parameters of a linear differential equation via the usage of the modified hybrid evolutionary algorithm for extremum seeking. The a priori information algorithm needed is only the dynamic system initial point or an estimation of the initial point and the sample of measurements: system output and, if there is one, system input.
Бесплатно
Background restoration in frame areas with small-size objects in video sequences
Статья научная
A general concept of removal of artificially overlaid images, natural damages of video images and other small-size objects is presented. The classification of artificially overlaid images is developed. The algorithms of feature points detection and feature points tracking used in video sequence restoration are considered.
Бесплатно
Buckling of orthotropic plates with the two free edges loaded for the pure in-plane bending moment
Статья научная
In this paper we have solved the buckling problem of orthotropic plates with two free and two simply-supported edges loaded for the pure in-plane bending moment. We have used the finite difference method to solve the problem.
Бесплатно
Cad system for perspective power supply network development task solution
Статья научная
The process of urban power supply network development is connected with need calculation and accounting a large number of parameters, possible development ways and complexity of their assessment. These circumstances require the introduction of new technologies for solving specified task. Declaration of author’s developed computer-aided design system (CAD system) ELNET for the task solution automation of perspective urban power supply network development is presented in article. Description of models, methods and algorithms based in the CAD system are given. CAD allows to create, correct, calculate parameters, look through and print models of urban power supply networks. ELNET consists of six connected modules: graphic module, control module (dispatcher), input/output module, solutions module, calculations module, reference data base. System possesses the friendly graphical interface allowing ease using. In CAD ELNET mathematical basis puts designed by author mathematical model of urban power supply network presentation as directed weighted graph and two methods of solving urban power supply network development task: the reduction method to the set of enclosed global minimization tasks and decomposition method. Both methods suggest dividing a given task into three subtasks of smaller dimension: 1. Subtask of definition the number and locations of new substations. 2. Subtask of definition the connection way of new consumers to network. 3. Subtask of definition the optimum connection way of new substations to the existing network. The optimization algorithms of subtasks solution are realized by the author. For solving subtask 1 three algorithms are designed and realized: algorithm based on the k-averages method; algorithm realizing the method of dividing clustering; heuristic algorithm. For solving subtask 3 three algorithms are also offered: heuristic algorithm of the reduced enumeration; genetic algorithm; algorithm based on constructing Voronoi diagrams. To solve subtask 3 the genetic algorithm is applied. Technical solutions represented in the article allow reducing time of design and increasing the quality of design decisions.
Бесплатно
Статья научная
The deformation of plates is reduced to the generalized problem of eigenvalues based on the stability criterion, which establishes equilibrium in the mechanical system. A method for calculating stability for thin plates under inertia loads exerting force on the basal plane is proposed. Having a differential formulation of the problem, the matrices are formed. The first is a stiffness matrix: it is based on Marie-Sophie Germain’s biharmonic equation. The second matrix represents the change of internal stresses or internal forces in the plate. The stiffness matrix is always symmetric and positive definite for the fixed plate. The matrix of the internal forces in the approximation of derivatives of functions under central differences, from the action of inertial forces can be asymmetric with respect to the main diagonal, can also degenerate and rows of this matrix is the feature of inertia loads. The finite difference method allows us to form a system of large dimensional equations. However, difficulties may arise at the free edges and corners of the plate, which complicates the calculation procedure. Therefore, a transition from the differential formulation of the problem to an integral formulation discretization with variational-difference method is performed. In this case a second row of nodes is not formed during the formation of the stiffness matrix at the free edge. The matrix of the internal forces is always symmetric; it can be ill-conditioned, however, this factor does not affect the problem of determining eigenvalues. Scientific literature provides many theoretical studies and solutions to practical tasks of calculating the stability of structures, including the calculation of longitudinal-transverse bending of thin plates. However, this is a task that has positively certain operators. We have conducted a research of the application of the variational-difference method for calculating the stability of structures. The differential formulation of the boundary value problem is transformed into a variational formulation; the stability criterion is solved; the issue of approximating differential operators for discrete problems with a finite number of variables is addressed in the paper. The paper also describes a developed set of algorithms for the Maple mathematical system and a compilation of calculating programs. Examples of the calculation are considered. We have studied a plate that is rigidly secured at one side while the other three sides are left unfixed. Values of the critical accelerations have been obtained. Problems are assigned to the generalized problem of eigenvalues in which the acceleration parameter, such as the parameter of load, is the only unknown property. Paper objective: the development of a method for calculating inertia loads on plates.
Бесплатно
Calculation method for automatic secondary power sources
Статья научная
The article describes methods for calculating the parameters of secondary power sources (SPS): rectifying devices and voltage impulse stabilizers. Algorithms for calculating parameters of SPS power circuits have been developed.
Бесплатно
Статья научная
A simple method for calculating the parameters of a forest fire is offered. The method is based on the representation of a fire as a mobile set on the surface of the Earth. The information base for the proposed methodology is the data of space monitoring of forest fires.
Бесплатно
Статья научная
Modern technologies make it possible to construct electronic devices that combine small sizes and high energy con- sumption, which requires the optimization of thermal modes. A promising direction to improve cooling intensity of the heat-loaded element (HLE) and precision of temperature control is applying thermoelectric modules (TEMs), which endow the heat release system with a cooling function, i. e., allow to reach temperatures of the HLE below ambient temperature. In the present paper, the processes of heat transfer in thermoelectric system of cooling and temperature control (TESCTC) are comprehensively considered. The temperature field in the capacity of heat-distributing plate (HDP), and influence of the heat flux inhomogeneity on the HLE temperature increase have been defined. The results of operating modes calculations, taking into account the heat-power release of HLE, performance of TEM, parameters of HDP and cooler, and magnitude of thermal resistance of thermal contacts have been presented. The calculation method allows to determine the temperature of HLE and to optimize TESCTC modes to achieve maximum cooling effi- ciency and lower energy consumption. It has been found that the optimal power supply current of TEM, corresponding to the modes with the maximum efficiency of cooling, depends on the thermal resistance of the heat sink system and the power of the heat load.
Бесплатно
Статья научная
The present paper describes an FPGA design of a camera-to-touchscreen demonstrator that has been prepared using Xilinx Vivado 2015.2 and SDK 2015.2 tools. The demonstrator consists of MicroZed 7020 Carrier Board, Avnet 7-inch Zed Touch Display and Avnet Toshiba Industrial 1080P60 Camera Module. The camera transmits a full HD video signal at 60 frames per seconds to MicroZed 7020 board, which processes it and sends to the LCD display with active area of 800×480 pixels. As the display has smaller resolution, only a fragment of the whole video frame can be seen at once on the display, whereas the full image is stored in the memory. By touching the screen one can travel along the stored video frame and look through the whole image. The design can be used, for example, as a car rear view mirror monitor benefiting from touchscreen technologies
Бесплатно
Краткое сообщение
The method of solving the boundary-value problems for hyperbolic system of the homogeneous quasilinear equations of two independent variables with the help of conservation laws is presented. This method is applied to basic boundary problems for the system of two-dimensional plasticity equations under Sent-Venan-Mises yield criterion, as well for the system under Coulomb's criterion.
Бесплатно
Combinatorial optimization in foundry production planning
Статья научная
The mathematical model of foundry production capacity planning is suggested in the paper. The model is produced in terms of pseudo-Boolean optimization theory. Different search optimization methods were used to solve the obtained problem.
Бесплатно
Company management system estimation on the basis of adaptive correlation to the environment
Статья научная
The method of the structure and indicators analysis of company business processes based on the calculation of simple correlation between historic series of expenses is offered.
Бесплатно
Comparative analysis of typical regulation algorithms and nonparametric dual control algorithm
Статья научная
The task of nonparametric dual control algorithm and standard regulation laws (P-, PI-, PID-regulators) at dy- namic objects with discrete-continuous nature of the technological process control is considered. It means that in itself, the dynamic process is continuous, however, the “input-output” variables of the process are controlled through discrete instants. In the case under study, the structure of the process model is partially parametrized. It means that equation order is determined from prior information, but at the same time functional dependency between “input-output” vari- ables of the process remains unknown. The methods of dynamic processes modeling and control based on nonparamet- ric algorithms are offered. The complexity of dynamic process modeling and control under condition of incomplete information is discussed. This level of prior information is characterised by the lack of model structure knowledge, but the information on object qualitative characteristics, for example, unambiguity, or ambiguity characteristics, linearity for dynamic processes or the nature of its nonlinearity is required. Methods of nonparametric statistics are applied to identification problem solving at this level of prior information. The problems of identification and control in the conditions of incomplete information are very relevant because many dynamic processes are not deeply studied and the presence of unknown distribution random noises causes more complexity in solving the identification and control tasks. The results of computing experiment which show the efficiency of nonparametric dual control algorithm in comparison with standard regulators are presented
Бесплатно
Comprehensive method for multimodal data analysis based on optimization approach
Статья научная
In this work we propose a comprehensive method for solving multimodal data analysis problems. This method in- volves multimodal data fusion techniques, multi-objective approach to feature selection and neural network ensemble optimization, as well as convolutional neural networks trained with hybrid learning algorithm that includes consecutive use of the genetic optimization algorithm and the back-propagation algorithm. This method is aimed at using different available channels of information and fusing them at data-level and decision-level for achieving better classification accuracy of the target problem. We tested the proposed method on the emotion recognition problem. SAVEE (Surrey Audio-Visual Expressed Emotions) database was used as the raw input data, containing visual markers dataset, audio features dataset and the combined audio-visual dataset. During the experiments, the following variable parameters have been used: multi-objective optimization algorithm - SPEA (Strength Pareto Evolutionary Algorithm), NSGA-2 (Non-dominated Sorting Genetic Algorithm), VEGA (Vector Evaluated Genetic Algorithm), SelfCOMOGA (Self- configuring Co-evolutionary Multi-Objective Genetic Algorithm), classifier ensemble output fusion scheme - voting, averaging class probabilities, meta-classification, as well as resolution of the images used as input for the convolu- tional neural network. The highest emotion recognition accuracy achieved with the proposed method on visual markers data is 65.8 %, on audio features data - 52.3 %, on audio-visual data - 71 %. Overall, SelfCOMOGA algorithm and meta-classification fusion scheme proved to be the most effective algorithms used as part of the proposed comprehen- sive method. Using the combined audio-visual data allowed to improve the emotion recognition rate compared to using just visual or just audio data.
Бесплатно
Consideration of optimal control of strictily hierarchical manpower system
Статья научная
The paper describes the problem of finding an optimal control strategy for the manpower control system. The equilibrium condition for the strict hierarchical manpower system control is stated which enables development of optimal strategy algorithm for one state example. Based on the equilibrium condition, the novel approach to the determination of optimal control in such system is described. Optimal tracking algorithm is described by example, which is implemented in MathematicaTM. The tracking algorithm is able to find the optimal values of the transition coefficients, so that the system achieves the desired value in one step. For the case when the desired value is not achievable in one step due to the boundary conditions, additional two algorithms are considered which bring state values to the desired ones in several steps. Two variants of the algorithm are considered, when the desired value is lower or greater than the initial value.
Бесплатно
Construction of elasto-plastic boundaries using conservation laws
Статья научная
The solution of elasto-plastic problems is one of the most complicated and actual problems of solid mechanics. Traditionally, these problems are solved by the methods of complex analysis, calculus of variations or semi-inverse methods. Unfortunately, all these methods can be applied to a limited number of problems only. In this paper, a technique of conservation laws is used. This technique allows constructing analytical formulas to determine the elasto-plastic boundary for a wide class of problems. As a result, the elasto-plastic boundaries were constructed for twisted straight rods with cross sections limited by piecewise smooth contour, for flexible consoles with constant cross-sections, as well as for anti-plane problems. Computer programs for construction of elasto-plastic boundaries for twisted straight rods were written using obtained technique. In this work, the elasto-plastic boundary arising during the torsion of a straight beam of arbitrary cross section, which is limited by a piecewise smooth contour is constructed; and the elasto-plastic boundaries for the problems of a consol bending and anti-plane deformation are found. The plan of the paper is the following. In the first section the basic equations of elasticity and boundary problems are considered; in the second section the basic equations of the theory of ideal plasticity of von Mises are given; in the third section the conditions on the boundaries of the elastic and plastic domains are formulated. The fourth section is devoted to torsion of elastic prismatic rods; the fifth one describes elastic bending of bars; in the sixth section the plane problem of theory of elasticity is given. The seventh section covers an anti-plane problem of elasticity theory; in the eighth section, conservation laws for the equations of elasticity are constructed; in the ninth one, conservation laws of two-dimensional equations of plasticity are discussed. In the tenth section an elasto-plastic boundary of a twisted straight rod is found; in the eleventh one an elasto-plastic boundary in the bended console is given; and finally, in the twelfth section a method for the construction of elasto-plastic boundaries for large areas is described.
Бесплатно
