Одним из важнейших факторов, исключающих возникновение дефектов типа пор, расслоений, участков с неполной полимеризацией связующего в формуемой высоконагруженной полимерной композитной конструкции, является управляемость процесса во всем объеме композита. Для обеспечения однородности процесса полимеризации связующего предложен метод многокритериальной оптимизации процесса на основе математической модели, связывающей процессы распространения тепла и кинетики полимеризации. Система связанных уравнений процесса, учитывающая экзотермическое тепло, выделяемое при полимеризации термореактивного связующего, изменение теплоемкости и теплопроводности композита при фазовых переходах от жидкого к гелеобразному и, далее, к твердому состоянию, точную геометрию технологической системы, включая прессформу, а также интенсивность тепловыделения независимо управляемых нагревателей, реализована в виде конечноэлементной модели. Предложенный метод синтеза закона оптимального управления нагревателями, использующий метод множеств Парето, проиллюстрирован на примере полимеризации разностенной композитной конструкции, формуемой из стеклопластика.
Keywords: Композиционные материалы; Процесс полимеризации; Оптимальное управление; Кинетические уравнения; Уравнения в частных производных в задачах управления и оптимизации, Конечно-элементное моделирование, Фронт Парето
This article considers the causes of halitosis and methods of the diagnosis. Halitosis, syndrome of bad breath caused by pathological condition of the oral cavity or internal organs and systems, has a significant impact on the patient's social life. Analysis of the composition of exhaled air may become a promising way to diagnose halitosis, as the direct relationship between the compositions of molecules of oxygen, carbon dioxide, nitrogen oxides, ammonia etc. and the causes of halitosis were found. The article's authors review and analysis the methods of measurement of qualitative and quantitative composition of exhaled air. The most common methods include the use of electrochemical, optical sensors, infrared spectrometers and mass spectrometers. The latter method is positioned as the most optimal method of analysis of exhaled air due to its high accuracy, selectivity and sensitivity. The authors' portable mass spectrometer being developed is represented. At this stage it can detect traces of oxygen and carbon dioxide, which inject into the device through the capillary system or membrane one, in gas samples in real-time mode.
Keywords: diagnosis of halitosis, molecular biomarkers, analysis of exhaled air, portable mass spectrometer
A mathematical model of heat transfer processes, the discrete model is based on the finite difference method, and the results of calculations of the temperature distribution also will be developed. In addition the program was created which allows to calculate the distribution of temperature over its entire length for given values of insolation, ambient air temperature and air velocity inside the collector
Keywords: mathematical modeling, finite difference method, heat transfer processes, solar collector
Results of research in the field of methods of classification of badly structured collections of heterogeneous documents are provided. The method is offered and the hybrid algorithm of classification of text documents is developed. The theoretical assessment of complexity of the offered method is executed and the pilot study is made. In article it is considered: mathematical model of the offered hybrid method, its algorithm, theoretical assessment of computing complexity and the experimental comparing with other methods of classification of documents.
Keywords: fuzzy logic, bayesian classification, classification of text documents.
The proposed method of designing hardware components optical switching systems simplifies prototyping and development of systems of optical switching and multi-core VLSI. This method allows to automatically set parameters of the optical system at the design stage, depending on the requirements. This method may be cost-effective at the stage of technical specifications of the project, as will reduce the time required for its coordination between the customer and the design engineer.
At the heart of developing a method of designing systems, optical switching elements is a comprehensive analysis of the equations and functions describing the electrical and optical properties of laser heterostructures, as well as electro-optic modulators and Fabry-Perrot resonators. Fundamental static and dynamic characteristics of semiconductor diode lasers can be calculated by using a set of kinetic equations describing the interaction of electrons, holes and photons in the active layer of the laser structure. At various stages of this method is processing, evaluation and calculation of the main characteristics of the elements of integrated optical switching systems.
Keywords: optical switching, integrated injection laser, quantum-scale heterostructure, amplitude modulation, terahertz range
In this work we have investigated the structure of individual single-walled and multi-walled carbon nanotubes by high-resolution electron microscopy and electron diffraction. To grow carbon nanotubes we used a catalytic chemical vapor deposition method. It was shown, that this synthesis protocol gave in general single-walled and double-walled carbon nanotubes with a high level of crystallinity. The diameters of the nanotubes were in the range 1.5 - 7 nm. We also observed that there was a certain level of amorphous carbon deposited on the nanotube surface during the growth. In this work we also present the structure analysis of the double-walled carbon nanotube by means of electron diffraction. We show that the structural date derived from electron microscopy and electron diffraction agree within the experimental error.
Keywords: Carbon nanotubes, electron diffraction, electron microscopy
The construction of moving part suspension of electrical-type measuring instrument was considered as well as analyses of its functioning was realized. The theoretical foundation of mathematical model construction of moving part suspension which describes the behavior of system, was set.
Keywords: moving part, taut band, beam, graph, matrix, incidence matrix, simulation, equation
A method of expanding the bandwidth and improve the performance of the differential voltage divider – attenuator (AT), which have parasitic capacitance on the outputs C01, C02. Wide range of transmission of the AT provided by introducing a compensation circuit C01, C02, which is achieving data quality indicators. Simulation results of desired are shown.
Keywords: a resistive voltage divider, differential attenuator, the parasitic сapacitance load, speed, upper frequency limit, analog-to-digital converters.
The processes happening in system of power supply of the AVO electric drive of gas are considered. The analysis is carried out and the assessment of consumption of electric energy of AVO of gas is executed.
Keywords: compressor station, device of air cooling of gas, mathematical statistics
The monitoring system of process of stabilization of levels of metal on continuous moulding of preparations machine, constructed useing the observer of a condition is considered. The developed nonlinear observer allows to increase the accuracy of an assessment of levels of the melted metal in the ladle with steel ,industrial ladle and crystallizers, and also makes continuous diagnostics of a condition of glasses of latches. The analysis made on the basis of linearized model, showed the observability and controllability of system on all interval of pouring.
Keywords: Machine of continuous moulding preparations,the controllability, the observability, the observer of a condition, the level of metal
The article devoted to the development of a conceptual desing methodology applied to the working parts of the rope excavator. As notation for the representation of models used the Unified Modeling Language (UML). Integration method diagram of target classes (DTC), the diagram of class equipment (DCE)and the diagram of functional target classes (DFTC) obtained the model system of management of the work equipment. A result of the conceptual constructing developed a basic invariant of the object architecture, implemented in innovative desing of the woring body.
Keywords: the target analysis, the conceptual construction, innovation, the working parts, the rope excavator
This paper present method of speed increasing differential and no differential driver (output stage transistor logic, emitter and source followers, the circuit of feedback amplifiers, etc.). Сonsiders conditions of correcting circuits design, which compensates the effect of the parasitic capacitance to its range of operating frequencies and the settling time of the transition process.
Keywords: drivers, emitter and source followers, operational amplifier, correcting circuit, performance, upper frequency limit, rise time transient, stability.
The article is concerned with problems of modern electrohydraulic converters control systems used to adjust wicket gate of Kaplan turbine. Linearized model of wicket gate servomotor is considered. Algorithm for online identification of parameters of servomotor is considered. Algorithm is based on recurrent least squares method. Algorithm for adaptive PI-regulator tunning is based on online optimization of functional of generalised work (FGW). Model experiments using real data show reducing maximum control error of servomotor position from 20 % to 1 %. Also methods for servomotor state diagnostic are considered.
Keywords: adaptive control system, diagnostic system, Kaplan turbine wicket gate, linearized models, identification, recurrent least square, functional of generalised work
The article deals with interference suppression algorithms that arise in the ECG signal by moving of the electrodes due to the motion of the object. It is proposed to use an adaptive filter, which reference signal is provided by the data triaxial accelerometer.
Keywords: electrocardiogram, adaptive filtering, motion artifacts, electrophysiological signal adaptation algorithm
Modern ultra-tight integration structure of strapdown inertial systems and global positioning system, based on the linearization of the navigation measurements and linearization of measurement errors models, are not not applicable for motor vehicles navigation. The adequate standard stochastic model of the vehicle perturbed motion has been synthesized. The model can be used for the integration Kalman filter. Such correlations can result in poor real-time estimation accuracy of navigation parameters of motor vehicle.
Keywords: motor vehicle, stochastic model, integration structure of strapdown inertial systems and global positioning system