The method of digital parametric measurement of the phase shift of signals with slowly varying amplitudes of the same slowly varying instantaneous frequencies was proposed. The numerical simulations and experiments on the developed hardware and software system were carried out. The error of measurement the phase difference of harmonic signals in the experiments were not more than 0,00001 radian. The method can be used in applications where the measured value is expressed in terms of the phase difference of quasi-harmonic signals.
Keywords: quasi-harmonic signal, phase shift, real time measurements, hardware and software system
To investigate the stability of the porous bearings developed computational model heterogeneous porous bearing of finite length. Given the permeability anisotropy of the porous layer in the paper the problem of stability of motion of a pin in the bearing for the two different versions of lubrication: the axial direction and in the direction perpendicular to the axis of the bearing. Obtained and analyzed the tasks identified areas of stability of motion spine.
Keywords: porous bearing, friction regime, the permeability of the porous layer, the viscoelastic lubricant.
In this paper a systematic study of individual single-walled and multi-walled carbon nanotubes was performed by Raman spectroscopy and high-resolution electron microscopy. We have presented the geometrical and electronic structure analysis on the examples of two tubes: individual single-walled and double-walled nanotubes. The role of different environmental effects and their influence on the final structure assignment are discussed. Moreover, we have shown that the Raman spectroscopy gives reliable estimations of the nanotube diameters and the conductivity. Given a non-destructible character of Raman spectroscopy, we may conclude that it is one of the most efficient methods for structure analysis of carbon nanotubes.
Keywords: Carbon nanotubes, Raman spectroscopy, electron microscopy
Proposed by parallel implementation structures aloritmicheskih simulating year-round circulation of water bodies. The research evaluation of computation time, find the optimal algorithm for the implementation of independent calculations for multi-core processors to reduce the computation time.
Keywords: parallelization of computations, thermohydrodynamics modeling of water objects, multi-core processors
The paper considers different approaches and tools for system log files analysis. Authors describe typical cases where such analysis is required. Requirements for a multipurpose log analysis tool are stated. Three classes of log analysis tools are discussed: specialized ones, real-time analysis tools and configurable analyzers. Advantages and disadvantages of these tools are summarized. Reviewed tools are assessed in the terms of compliance to the stated requirements. Configurable analyzers are considered to be the most suitable tools for described tasks.
Keywords: system logs, semistructed form, pattern, structure recognition, records filtration
The view of Finnish experts on the development of the electricity market in Finland for the period up to 2035. Is marked by the expected growth in nuclear power and wind power, as well as increased attention to the use of fuel wood.
Keywords: nuclear, biofuels, wind power market, electricity
The represented approach of dynamic process modeling is based on the technology of automatical semantic text analysis. An associative network is forming during text processing. Its key notions, including lexical and psycholinguistic markers of the analyzed process, are ranked by theirs semantic weight. The weight being multiplied by marker status value at the scale of “good-bad” gives its contribution to the process stage characteristic. Transformation of the accumulated for all of the markers process characteristic from one period of time to another one is characterize a direction of the process.
Keywords: automatical text processing, associative (homogenous semantic) network, process dynamic modeling, social processes, lexical and psycholinguistic markers
The urgency and feasibility of application of biosensors with active biological layer for environmental studies was justified. A study of biosensors of various configurations to build a test system of environmental pollution control and determine the degree of aquatic toxicity was conducted. A simulation model of biosensor system was built. The selectivity of the biosensor was determined by theoretical experiments in which the analytical signal of the biosensor for biologically active layer without other biologically active substances was determined. The relationship between the type of transducer and biologically active substance was revealed. The software implementation of bisensor system was developed that reveals a number of pollutants and allows using not only different converters, but also different strains.
Keywords: biosensor, strain, quartz crystal, simulation model, environmental studies, pollutants, toxicity, sensitivity
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
Results of comparing the beamwidth and the concentration factor of receiving antenna wich were calculated using the metods of Bartlett and Prony when working on the background noise of the sea are considered. It was shown that efficiency parameter estimation signal sources using Prony methods is higher than when using the method of Bartlett.
Keywords: Prony algorithm, vector-scalar array,dynamc sea noise, the covariance, the flow of power
Possibility of receiving lungs self compacting concrete is considered. The technique of a choice of components of a raw mix is offered and are brought physics - mechanical characteristics of a ready construction materia
Keywords: Self-compacting concrete, the supersoftener, knitting, filler.
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.
We consider the problem of the use of adaptive autonomous scripts in the decision of problems of management of information resources of computer systems. Developed a conceptual model of adaptive autonomous script with use of frames and apparatus of finite automata, which expands the possibilities of automation of complex problems of information resources management
Keywords: adaptive autonomous scripts, theory of finite automata, frame, slot, management of distributed information resources.