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«System analysis and applied information science»

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No 4 (2016)
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System analysis

4-10 782
Abstract

This paper shows a generalized approach to procedures of control and analysis of vita-medium properties when «the subjective sensor system» is used. The state of vita-medium is determined on the basis of the applied sources of expert assessments which reflect its properties in the natural language by means of aggregation of quantitative and qualitative features. Being so, a totality of information sensor images of vita-medium is formed, which represent a certain informational coherence and characterize vita-medium as a specific coherence.

It is shown that the creation of information images is carried out according to the known principles of formalized subjective description of complex systems. Accordingly, the technology of formalized presentation of information flows and sensor images is considered in the process of vita-medium modeling with the use of categorical variables. Possible vita-medium structuring is shown at practically any complexity level with the aid of the following components: need; idea; resources; results; construction.

Organization of data structures has been analyzed for formation of the intelligent vita-medium, and external, systematic and physical levels in the intelligent model base have been provided. A peculiarity of data is that in the vita-medium model it is relevant to certain material objects of the real world, to physical or informational processes. This provide data filling with the distinctive contents having the principal meaning for a set of functional tasks resolved in the intelligent model volume.

11-16 1079
Abstract

The article is devoted to problem of material management arising in the implementation of projects for the development and creation (modernization) of the new techniques. The uniqueness of the projects, their limit on the cost and time does not allow the use of traditional approaches to resource management. Such projects are often implemented in the development of companies; where it is not possible to abandon the traditional operating methods of management. The aim of the article is a formalization of the process of material management of projects, a description of its information flows for integrate into the project management practices and for improve the efficiency of material management. For the systematization of information arising from the material resources management, invited the set-theoretic representation of the management process. According with the requirements of project management standards were described the sets and defined rules of their transformation. Specification of the set-theoretic representation helped to establish the area and limits of the modelling process. Further decomposition process became the basis of the functional model, constructed in accordance with the methodology IDEF 0. A graphical representation of the model allows you to visualize the process at different levels of detail. For specification of issues related to the organization and promotion of material flow, were developed functional models of sub-processes and were described the identified data-flows. For the harmonization of process and project approaches formulated conditions for evaluating the efficiency of material management. The developed models can be the basis for designing the structure of companies, for regulation of their project activities, as well as for establishing an information system of management resources of projects.

17-23 1010
Abstract

The algorithm of preparation and sampling for training of the multiclass qualifier of support vector machines (SVM) is provided. The described approach based on the modeling of possible changes of the face features of recognized person. Additional features like perspectives of shooting, conditions of lighting, tilt angles were introduced to get improved identification results. These synthetic generated changes have some impact on the classifier learning expanding the range of possible variations of the initial image. The classifier learned with such extended example is ready to recognize unknown objects better. The age, emotional looks, turns of the head, various conditions of lighting, noise, and also some combinations of the listed parameters are chosen as the key considered parameters for modeling. The third-party software ‘FaceGen’ allowing to model up to 150 parameters and available in a demoversion for free downloading is used for 3D-modeling.

The SVM classifier was chosen to test the impact of the introduced modifications of training sample. The preparation and preliminary processing of images contains the following constituents like detection and localization of area of the person on the image, assessment of an angle of rotation and an inclination, extension of the range of brightness of pixels and an equalization of the histogram to smooth the brightness and contrast characteristics of the processed images, scaling of the localized and processed area of the person, creation of a vector of features of the scaled and processed image of the person by a Principal component analysis (algorithm NIPALS), training of the multiclass SVM-classifier.

The provided algorithm of expansion of the training selection is oriented to be used in practice and allows to expand using 3D-models the processed range of 2D – photographs of persons that positively affects results of identification in system of face recognition. This approach allows to compensate in a certain measure a lack of initial images for identification improvement of quality.

Management of technical objects

35-30 1185
Abstract

This article discusses: model of the two-link mechanism; generalized scheme of mechatronic simulation model of 3D-printer with the positioning units of electric DC; mathematical model of the actuator of the printer unit in the form of a system of differential equations; 3D-printer programming model implemented in the Matlab-Simulink environment using the c standard library blocks and SimMechanics library; virtual (animated) 3D printer model on the basis of the library Simulink 3D Animation, supports the visualization of the movements of the designed mechanism of the basic units. We present the initial data and the results of simulation of 3D-printer type Scara as a waveform positioning actuator (extruder) in the manufacture of test items by fusing plastic.

31-37 642
Abstract

This article presents a method of imparting desired filtering properties for closed-loop control system. The method is based on using of input rate limiter and synthesis of special digital controllers within ideal low-pass filters. Synthesis of the controllers was made using third-order astatic plant and different ideal low-pass filters. Considering the control objects saturation zone and required bandwidth, input rate limiter was calculated. The digital modeling and comparative analysis are applied. The author offered practical guidelines for using results of investigation.

38-44 951
Abstract

The article discusses and proves the feasibility of using the proposed system balancing Li-ion battery consisting of a plurality of series-connected cells, applied to hybrid and electric transportation. The main objective of the system is to increase the performance and operating time of Li-ion batteries.

Data processing and decision–making

46-52 993
Abstract

This paper extends the recently introduced approach for modeling and solving the optimal control problem of fixedswitched mode DC-DC power converter. DCDC converters are a class of electric power circuits that used extensively in regulated DC power supplies, DC motor drives of different types, in Photovoltaic Station energy conversion and other applications due to its advantageous features in terms of size, weight and reliable performance. The main problem in controlling this type converters is in their hybrid nature as the switched circuit topology entails different modes of operation, each of it with its own associated linear continuous-time dynamics.

This paper analyses the modeling and controller synthesis of the fixed-frequency buck DC-DC converter, in which the transistor switch is operated by a pulse sequence with constant frequency. In this case the regulation of the DC component of the output voltage is via the duty cycle. The optimization of the control system is based on the formation of the control signal at the output.

It is proposed to solve the problem of optimal control of a hybrid system based on the formation of the control signal at the output of the controller, which minimizes a given functional integral quality, which is regarded as a linear quadratic Letov-Kalman functional. Search method of optimal control depends on the type of mathematical model of control object. In this case, we consider a linear deterministic model of the control system, which is common for the majority of hybrid electrical systems. For this formulation of the optimal control problem of search is a problem of analytical design of optimal controller, which has the analytical solution.

As an example of the hybrid system is considered a step-down switching DC-DC converter, which is widely used in various electrical systems: as an uninterruptible power supply, battery charger for electric vehicles, the inverter in solar photovoltaic power plants.. A qualitative change in the projected illustration of the control signal, a sequence of control pulses and output management object (inverter).

53-60 8303
Abstract

The short review of microcontrollers of family Arduino, their characteristics and application fields is given. Importance of record of parameters of researched object is marked to produce debugging of control systems on microcontrollers Arduino. Unique possibility of registration of parameters in family Arduino is record on SD a card in an alpha mode with usage of functions print ()write (). The problems connected to record of the binary data on SD a card on microcontroller Arduino Due are considered. The analysis of methods of record of the binary data on SD-card Arduino Due, originating problems with neocleaning of memory from the previous program leading to possibility of duplication of the data on SD to a card, presence of the erratic point of view about restriction of volumes of data record and necessity of usage become outdated SD-cards is carried out. Ways of elimination of the marked lacks are considered. The estimation of high-speed performance of various approaches of a data recording on SD a card is led. On the basis of the led researches the approach of multiplexing of the writeable information at the expense of conversion of the binary data is offered is byte-serial in a character array in code ASCI without magnification of their volume and record by units on 240 byte. It allows to use as much as possible standard function possibilities write () Arduino and specificity of the organization of memory SD of cards and to increase high-speed performance more than in 1100 times in comparison with record in a character type on one byte.

It is marked that usage of decisions of an exception of duplication of the data offered at forums does not provide completeness of their elimination. For Arduino Due for storage cleaning it is necessary usages of the special programmator or setting of the new program of loading.



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ISSN 2309-4923 (Print)
ISSN 2414-0481 (Online)