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Using the remote sensing methods is the most promising for day-to-day control of oil pollution. The laser-induced fluorescence method provides efficient detection and classification of oil pollutions. To monitor oil pollutions on the earth surface is more complicated than on the water one because of lower fluorescence intensity and interfering fluorescence of natural objects available on the earth surface.Properties of oil pollution classifiers depend largely on the number and positions of spectral bands of fluorescence registration. Reducing the number of spectral bands allows us to diminish computation complexity and cost of equipment. In some cases the reduction increases classification accuracy. The number of spectral bands can be reduced through increasing their width.The paper presents mathematical modeling of oil pollution detection and classification. The experimentally obtained fluorescence spectra of oil pollutions on different substrates were used as input data. The k-nearest neighbors algorithm was used to detect and classify oil pollutions. Cross validation was applied in mathematical modeling.The mathematical modeling results have shown that for oil pollutions detection using over 8 spectral bands (band width less than 50 nm) a classification error rate does not depend on the further increasing number of the spectral bands.As to the type classification of oil pollutions (4 classes), an increasing width of the spectral bands up to 60 nm (the number of spectral bands reduced up 7) does not lead to a significantly decreasing overall classification accuracy.In the case of the sort classification of oil pollutions (8 classes) a local maximum of the overall accuracy has been observed at 25-30 nm width of the spectral band (14-16 spectral bands). The spectral resolution improvement (increasing the number of bands) does give an essentially increasing accuracy.The paper has shown that to detect and classify oil pollutions on the earth surface there is no need to acquire fluorescence with high spectral resolution and numerous spectral bands.

The paper deals with identifying linear dynamical systems from the experimental data obtained through applying the test signals to the system. The paper objective is to determine both the form and the coefficients of the transfer function retrieved from the hodograph samples experimentally at bench test. The order of the frequency transfer function of the system being identified was assumed to be unknown. It was expected that in obtaining the frequency characteristics of a real system there would be noise during the experiment as a result of which the points of the experimentally obtained hodograph would be randomly shifted. As a model, a certain transfer function of the system was adopted. The authors proposed to find a solution of the identification problem in the class of hodographs specified by the model of the system. The search for unknown coefficients of the transfer function of the system model is carried out by minimizing a proximity criterion (measure) - described and published earlier by one of the authors - between the experimentally received system hodograph and the system model on an entire set of the experimental points of the system hodograph and the hodograph of the system model. The solution of linear dynamic system identification from the frequency hodograph was reduced to solving a system of equations of the system model frequency transfer function that is linear with respect to unknown parameters.The proposed identification algorithm allows us to determine the order of the frequency transfer function of the identified system from the experimentally obtained samples of the frequency hodograph of the system. For dynamic systems of the fifth order at most there is software developed to simulate the process providing the pseudo-experimental data with random errors and determining the parameters of such systems.A computational experiment has been carried out to evaluate the error with which the proposed algorithm determines the parameter values of the system to be identified. The illustrative computational experiment has shown that using the proposed algorithm for identifying a linear dynamic system from the frequency hodograph the error in determining the coefficient values of the frequency transfer function of the system is comparable with a range of measuring error in the experimental samples of the hodograph of this system. In known sources on identification of linear dynamic systems there is no method of identification this publication describes. This identification method of linear dynamic systems can find application in experimental testing, verification tests in situ and iron bird tests for vehicles of various purposes.

The paper analyses the known available method to search for the author of the text in the natural language base of knowledge proposed by O. Khrulev in which the minimum distance between the frequency dictionaries of the presumed authors and the text under analysis is accepted as a criterion for the successful identification of the author. The patterns and drawbacks of the method are revealed.The paper suggested that since the distance value is based on the average values of this lexeme-usage in all papers of the author on the basis of which frequency dictionaries are created, such leaps will show up when the specific value of the lexeme-usage frequency stands in stark difference to the average one.To test this hypothesis, the paper determines a variation coefficient of each lexeme-usage frequency in the texts under analysis.The analysis of frequency dictionaries of Russian canonical writers conducted in the paper has shown that on average about 90% of the authors' frequency dictionaries contain lexemes whose frequencies of usage are inhomogeneous.The author of the paper suggested that the coefficient of variation shows increase in author's word-hoard, i.e. the larger the vocabulary size, the richer the speech, and, therefore, the less frequently the author uses the same lexemes.In the paper there is a hypothesis that it is wrong to reduce the analysed size of the authors' frequency dictionaries only by critical boundaries: it is necessary to analyse lexemes with a variation coefficient over 33%, which illustrate rich word-hoard.The paper also proposes to define only one specific critical boundary of 10 thousand lexemes, since the indefinite boundary of 5 - 10 thousand lexemes offered by O. Khrulev makes it difficult to identify the author of unknown text. In this case, the lexemes with a variation coefficient over 33% of the total vocabulary size of the studied authors beyond the critical boundary are subjected to analysis.To test this hypothesis, a numerical experiment was carried out. The main point of the experiment was to identify the authors of unknown texts based on the authors' frequency dictionaries. At the same time, there were no unknown texts in the data compilation of the frequency dictionaries. The identification was based on the calculation of distance from the unknown text to the authors' frequency dictionaries, i.e. according to O. Khrulev’ s technique. In calculation different critical boundaries were specified.A numerical experiment has shown that the method proposed in the paper increases the successful identification percent for the larger size texts (more than 5,000 word forms) by 12.5%, and for texts of small size (less than 5,000 word forms) by 15.2%.

The paper presents the analysed and systemised results of the experimental study of laser gyro (LG) errors. Determines a structure of the resulting LG error, as a linear combination of the random processes, characterizing natural and technical fluctuations of difference frequency of the counter-propagating waves, with a random constant zero shift available in the sensor readings. Formulates the requirements for the structure and form of the analytic description of the error model. Shows a generalized model of the LG fluctuation processes, on the basis of which a mathematical model of LG errors was developed as an inertial sensor.The model is represented by a system of the stochastic differential equations and functional relationships to characterize a resulting error of the sensor. The paper provides a correlation analysis of the model equations and final equations obtained for the mean-square values of the particular components, which allow us to identify the resulting error parameters. The model parameters are presented through the values of the power spectral density of the particular components. The discrete form of the model is considered, the convergence of continuous and difference equations is shown in fulfilling conditions of the limiting transition. Further research activities are defined.

The paper considers a problem of difficult accessibility and low quality of data on the reliability parameters of the vehicle system components and the difficulties arising from this problem to estimate the reliability parameters of the systems themselves as statutorily required and in terms of international standards (e.g. ISO 26262). As a problem solution, the paper proposes a method for adjustment of the system reliability estimates based on the field observation of system failures. The method based on a Kalman filter uses non-parametric definition of the failure probability distribution (quantile «folding» of the distribution) with subsequent «unfolding» via Monte Carlo.A mathematical model shows how to use this method. For clarity, the estimates of reliability parameters are given at the time of rollout (100 % of systems are in working order) and upon the failure of 25%, 50%, 75% and 100% of produced systems, respectively. A КК plot shows that the reliability estimates gradually become close to the field reliability data.The method allows, by varying filter parameters, a more conservative estimate of the reliability parameters or an estimate, which is more in accord with the field data. Thus, the results can be used at all stages of the system lifecycle, namely when developing, manufacturing and upon completing production for the aftermarket services.

The future nanoelectronics development involves using the smaller- -and-smaller-sized circuit components based on the micro- and nanostructures. This causes a growth of the specific heat flows up to 100 W/cm2. Since performance of electronic devices is strongly dependent on the temperature there is a challenge to create the heat transfer models, which take into account the size effect and ensure a reliable estimate of the thermal conductivity. This is one of the crucial tasks for development of new generations of integrated circuits.The paper studies heat transfer processes using the silicon thin films as an example. Thermal conductivity calculations are performed taking into account the influence of the classical size effect in the context of the Sondheimer model based on the solution of the Boltzmann transport equation.The paper, for the first time, presents and considers the influence of various factors on the thermal conductivity of thin films, namely temperature, film thickness, polarization of the phonon waves (transverse and longitudinal), velocity and relaxation time versus frequency for the phonons of different wave types.Based on the analysis, three models with different accuracy are created to estimate the influence of detailing processes under consideration on the thermal conductivity in a wide range of temperatures (from 10 K to 450 К) and film thickness (from 10 nm to 100 µm).So in the model I for the first time in calculating thermal conductivity of thin films we properly and circumstantially take into account the dependence of the velocity and the relaxation time of phonons on the frequency and polarization. The obtained values are in a good agreement with available experimental data and theoretical models of other authors. In the following models we use few average methods for relaxation times and velocities, which leads to significant reduction in calculating accuracy up to the values exceeding 100%.Therefore, when calculating the thermal conductivity for micro - and nanostructures it is necessary to employ a detailed process description of the phonons propagation for different energies (frequencies) and polarizations, and consider the real dispersion relations (velocities of their propagation) for each concerned temperature and thickness of the sample.The above recommendations can be used to estimate the in-plane thermal conductivity of thin films when simulating the new structures in advanced semiconductor devices.

To ensure many production processes are used compressors of various types, including turbochargers, which produce compressed air. The actual performance values of turbochargers used in highlands are significantly different from the certified values, and parameters of compressed air do not always guarantee the smooth and efficient functioning for consumers.The paper presents research results of the turbochargers of 4CI 425MX4 type, a series of "CENTAC", manufactured by INGERSOL – RAND Company. The research has been conducted in industrial highland conditions in difficult climatic environment. There were almost no investigations of turbochargers running in highland conditions. The combination of low atmospheric pressure with high temperature of the intake air causes the abnormal operating conditions of a turbocharger. Only N. M. Barannikov in his paper shows the results of theoretical studies of such operating conditions, but as to the practical research, there is no information at all.To normalize the turbocharger operation an option of the mechanical pressurization in the suction pipe is adopted. As a result of theoretical research, a TurboMAX blower MAX500 was chosen as a supercharger. The next stage of theoretical research was to construct characteristics of the turbocharger 4CI 425MX4 with a mechanical supercharger in the suction pipe. The boost reduces to the minimum the time of using additional compressors when parameters of the intake air are changed and ensures the smooth and efficient functioning for consumers.To verify the results of theoretical studies, namely, the technique for recalculation of the turbocharger characteristics under the real conditions of suction, were carried out the experimental researches. The average error between experimental and theoretical data is 2,9783 %, which confirms the validity of the technique used for reduction of the turbocharger characteristics to those under the real conditions of suction.

The paper analyses a technique to calculate the Leontiev tube and shows that there are several ways to increase operating efficiency of this device of gas-dynamic energy separation. Application of regular relief (dimples and protrusions) on the wall between supersonic and subsonic channels is one of them.Analyses the results available in publications of experimentally numerically investigated influence of semi-spherical protrusions in the slot channels on the enhancement of heat transfer and drag coefficients at various Reynolds numbers.Shows that at the laminar flow owing to semi-spherical protrusions in the slot channel a heat transfer coefficient can be 1.1‑2.6 times increased with simultaneous 1.7‑4.8 times growth of drag coefficient (as compared to the smooth channel).At transition and turbulent flows the heat transfer enhancement, because of shallow dimples (depth-to-print diameter ratio is from 0.1 to 0.25), can reach 1.1‑2.4 times, with simultaneous 1.2‑7.9 times growth of the drag coefficient (as compared to smooth channel).Using the higher protrusions can provide up to 3.0‑3.5 times heat transfer intensification, but in this case there is an outrunning growth of the drag coefficient.It is shown that the staggered array of the shallow spherical protrusions is advisable to use for heat transfer enhancement in the subsonic channel of the Leontiev tube. The shallow spherical dimples correspond to them and operate as heat transfer intensifiers in the supersonic channel.The paper proposes a mechanism that enables taking into consideration an impact of the protrusions in the slot channel on the intensification of the heat transfer and momentum processes when calculating the gas-dynamic energy separation device (Leontiev tube) using the known (earlier published) technique.The study has been implemented under supporting Grant no. 15-08-08428 of the Russian Foundation for Basic Research.

The on-line detection of pipeline spillage is really essential for the fast oil spill response to the ecological and economical consequences. However existing on-line pipelines spillage detection systems have a sensibility of 0.2 – 1 % of pipe flow and do not detect the smaller-sized spillages.For unpeopled or sparsely populated regions an advanced technique for detection of pipeline spillages (including low-intensity ones) is to monitor oil pollution (petroleum spills on the earth surface) along the pipeline using, for example, an air drone.The laser remote sensing method is an effective method to detect the pipelines spillage.The paper is dedicated to development of laser fluorescence detection method of oil pollution. The remote sensing laser method to monitor oil pollution is based on the fluorescence excitation of oil in UV spectral band and on the data record of the earth surface laser-induced fluorescence radiation.For laser fluorescence method of monitoring oil pollution the paper presents a comparative analysis of 0.266 and 0.355 µm wavelengths of the fluorescence excitation in terms of earth atmosphere propagation, eye-safety, laser characteristics, and petroleum fluorescence excitation efficiency.It is shown that in terms of eye-safety, laser characteristics, and propagation in the earth atmosphere a 0.355 µm laser wavelength of the fluorescence excitation has a sure advantage.In the context of petroleum fluorescence excitation efficiency a 0.266 µm laser wavelength of the fluorescence excitation has the advantage, but this advantage depends heavily on the petroleum base. For low-sulfur (sweet) oil for instance, it is not that big.At large, in solving the task of oil pollution detection because of the oil pipeline spillages the 0.355 µm wavelength of fluorescence excitation ought to be preferable. However, when creating a monitoring system for the pipeline with a specific petroleum base the irreversible decision depends on the fluorescence excitation efficiency at 0.266 and 0.355 µm wavelengths of fluorescence excitation for a specific petroleum base.

The paper presents results of a steady three-dimensional numerical simulation of a flat evaporator and compensation chamber (CC) of a loop heat pipe (LHP) and describes a procedure of the thermal state calculation of the evaporator and the compensation chamber.The LHP is an efficient heat transfer device operating on the principle of evaporation-condensation cycle. It is successfully used in space technology and also to cool the heat-stressed components of electronic devices and computer equipment. The authors carried out a numerical study of the influence of the condensate pipeline length, immersed in water, on the thermal state of the evaporator and the compensation chamber. The paper shows the influence of the mass forces field on the calculation results. Presents all the numerical studies carried out by the authors for a brass flat evaporator with a thermal load of 80 W. Water is used as a LHP heat-transfer fluid. Fields of temperature, pressure and velocity are presented for each design option.Based on the calculation results, the authors came to the following conclusions:Influence of the mass forces field for the LHP of this type is significant and leads to arising water vortex flow in the condensate pipeline and CC, thereby mixing and equalizing the water temperature in the CC and in the porous element, reducing the maximum temperature of the porous element;The increasing section length of the condensate pipeline in the CC leads to increasing velocity of the heat-transfer fluid in the CC and in the porous element, decreasing mixing zone of the condensate in the CC, and increasing temperature non-uniformity of the porous element.

The paper deals with matters related to the adjustment training of the specialist who has specified competences in order to solve the specific staffing problems of enterprises, provide scheduled staff re-training, suggest additional specializations to graduates of educational institutions, etc. Defines a structure and content of the management system elements for training and adjustment training of specialists, including a shift from activity-related competence to desirable areas of knowledge, and therefrom to the curricula and programmes.A concept of the knowledge subject is defined. It allows perceiving a specific subject area. A concept of the aspects of the certain knowledge subject is proposed, and in this case it is assumed that the knowledge subject can be represented as a finite set of aspects of the given subject of knowledge. A concept of the knowledge section is defined as a body of knowledge, reflecting some aspect of the particular subject of knowledge. Thus, the entire body of knowledge to be offered by the particular Department may be represented by a variety of specific sections of knowledge. For each section of knowledge is introduced a concept of the training level, which corresponds to the level of detail and quality of the educational material delivered. To assess the level of training it is possible to use the method of expert’s estimates.The paper suggests a scheme that allows realization of the relevant order for target training of specialists. Requirements for training specialists are represented as a competency model of the specialist; an implemented study programme is characterized by the competences, obtained as the learning outcomes.The content of knowledge, corresponding to some competence, is represented as a total of all the sections of knowledge related to the aspects generated by the competence. Then the competence can be revealed through the body of knowledge. As a result, both an order for adjustment training and a Department can be defined as a set of the knowledge sections with indication of quality levels. The concepts of general knowledge, a lack of knowledge, knowledge residue were defined when comparing the weighted knowledge content of the order and the weighted knowledge content of the Department.The paper introduces an indicator of the level of requirements, which value shows a difference of the order-required level of training for the aspect from the level of training provided by the Department. The order-unclaimed knowledge forms the graduate’s general knowledge. This allows you to adjust the amount of additional knowledge to implement the order. To do this, we introduce the concept of a connectivity factor, which takes the value in the range [0,1]. The experts specify this factor, and the more is its value, the higher is the connectivity of the order materials and the knowledge residue.The obtained results make it possible to create an optimal technique (including automated) for adjustment or target training of specialists who possess basic education. In addition, this technique allows a customer to select the most desirable basic Department to organise target training.

The paper considers the composition of liquid radioactive wastes from the nuclear plants. Using traditional ways to extract organometallic compounds formed, when using the deactivation solutions to clean the surfaces of nuclear plant rooms, are complicated. The paper studies the edge-cutting methods of solving this problem. Its proposal is to use a combined ultraviolet treatment for organometallic compounds degradation based on ethylenediaminetetraacetic acid (EDTA) via pulsed xenon lamps. A potential use of the tubular and spherical geometry lamps is examined and advantages, disadvantages and features of these lamps are described. Instead of the pure EDTA the experiments used its disodium salt (Na2-EDTA). The hydrogen peroxide was used as an extra oxidizer. Absorption spectrums of solutions with various Na2-EDTA - hydrogen peroxide ratio were measured. It is found that the absorbance curve maximum is in the shortwave spectrum region (λ < 210 nm). The use of amalgam lamps of monochromatic radiation at wavelength λ = 254 nm will result only in formation of hydroxyl radicals but direct destruction processes of EDTA molecules due to radiation will be rare, and this decreases efficiency of their use.The spectral radiation characteristics of various continuum spectrum pulsed xenon lamps was measured. The experimental data expressed in relative units were compared with the emission spectrum of an absolutely black body. The paper shows that in spherical lamps high brightness temperature can be reached. Thus, in spherical lamps it is possible to obtain a spectrum, which is in maximum correlation with the absorption spectrum of the solutions under study, thereby making them a prospective radiation source for photo-degradation of EDTA compounds. For drawing a final conclusion it is necessary to conduct researches in order to compare Na2-EDTA degradation via tubular and spherical xenon lamps.

The paper considers one of the important aspects to gain efficiency of conducted computational experiments, namely to provide grid optimization. The problem solution will ultimately create a more perfect system, because just a multivariate simulation is a basis to apply optimization methods by the specified criteria and to identify problems in functioning of technical systems.The paper discusses a class of the moving objects, representing a body of revolution, which, for one reason or another, endures deformation of casing. Analyses using the author's techniques have shown that there are the following complex functional dependencies of aerodynamic characteristics of the studied class of deformed objects.Presents a literature review on new ways for organizing the calculations, data storage and transfer. Provides analysing the methods of forming grids, including those used in initial calculations and visualization of information. In addition to the regular grids, are offered unstructured grids, including those for dynamic spatial-temporal information. Attention is drawn to the problem of an efficient retrieval of information. The paper shows a relevant capability to run with large data volumes, including an OLAP technology, multidimensional cubes (Data Cube), and finally, an integrated Date Mining approach.Despite the huge number of successful modern approaches to the solution of problems of formation, storage and processing of multidimensional data, it should be noted that computationally these tools are quite expensive. Expenditure for using the special tools often exceeds the cost of directly conducted computational experiments as such. In this regard, it was recognized that it is unnecessary to abandon the use of traditional tools and focus on a direct increase of their efficiency. Within the framework of the applied problem under consideration such a tool was to form the optimal grids.The optimal grid was understood to be a grid in the N-dimensional cube, where N is the number of variable parameters, the calculations of functions on which meet the specified accuracy.In computational experiments the grid sizes have been increased step-by-step, with the data sets being reconstructed and the residuals being calculated. The tolerance values were visualized using the level lines on the functions of errors. Special attention was paid to the pitching moment, which is directly connected with the stability problem of of the body movement. Here not only answering the question on the mean square error of calculations is important, but also the change of the sign of the moment coefficient.It turned out that despite the available errors, there was no sign change observed. We have also identified areas of overstatement and understatement of the aerodynamic coefficients (ADC) when using the larger grids. Noted that when preparing the grid, the prerequisite is to identify areas of finding the system at the boundaries of stability.The calculation results have shown that as compared to the exact calculations the moment is underestimated. Moreover, taking into account the opposite sign of the dependence on the angle of attack in modulus, the moment is overstated; there are overestimations of the lifting force, resistance in the modulus and damping in the operating range.The choice of the optimal grid for evaluation of the mean square error led to a rather small grid, so a capability to introduce a grid of the variable size was considered. It was proposed to divide the grid into two parts. In the region of problem areas an estimate of the allowable increase of size is based on the analysis of a Pareto front of the relative derivative (increment) function. After scaling we have obtained the Nash equilibrium point. For the remaining areas the grid is to be selected either according to the tolerable error (with a constant size) or using an equality principle of the function increments.The proposed approach to select the mixed grids enables the significantly reducing number of points used when forming the ADC data arrays.A final criterion of the proper grid choice was a simulation of the body movement dynamics with used grid functions of ADC. Formulas for equations in deviations to describe a perturbed movement because of coarsening grids were derived. Analysis based on the information about the deformations when enlarging the grid has shown that the perturbed movement remains stable. Deviations, observed in the first phase of movement occur because of a decreasing oscillation period in coarsening a grid, which is quite understandable because of trends of changing ADC within the dynamic coefficients used in calculations of the oscillation period.Thus, the article shows the impact of consolidation of grids on the change nature of aerodynamic coefficients. To estimate were used the dependencies of deviations and normalized standard errors of the indicators of grids consolidation. Special attention was paid to identifying the areas of underestimation and overestimation, including zero crossing for pitching moments and damping ratio. The paper proposes a technique for a reasonable selection of grid sizes in multivariable analysis of the body movement dynamics, including deformed ones, on the basis of Pareto-tests of normalized errors.

The current steady-rising interest in using the unmanned multi-rotor aerial vehicles (UMAV) designed to solve a wide range of tasks is, mainly, due to their simple design and high weight-carrying capacity as compared to classical helicopter options. Unfortunately, to solve a problem of multi-copter control is complicated because of essential nonlinearity and environmental perturbations. The most widely spread PID controllers and linear-quadratic regulators do not quite well cope with this task. The need arises for the prompt adjustment of PID controller coefficients in the course of operation or their complete re-tuning in cases of changing parameters of the control object.One of the control methods under changing conditions is the use of the sliding mode. This technology enables us to reach the stabilization and proper operation of the controlled system even under accidental external exposures and when there is a lack of the reasonably accurate mathematical model of the control object. The sliding principle is to ensure the system motion in the immediate vicinity of the sliding surface in the phase space. On the other hand, the sliding mode has some essential disadvantages. The most significant one is the high-frequency jitter of the system near the sliding surface. The sliding mode also implies the complete knowledge of the system dynamics. Various methods have been proposed to eliminate these drawbacks. For example, A.G. Aissaoui’s, H. Abid’s and M. Abid’s paper describes the application of fuzzy logic to control a drive and in Lon-Chen Hung’s and Hung-Yuan Chung’s paper an artificial neural network is used for the manipulator control.This paper presents a method of the quad-copter control with the aid of a neural network controller. This method enables us to control the system without a priori information on parameters of the dynamic model of the controlled object. The main neural network is a MIMO (“Multiple Input Multiple Output”) system approximating the control signal for the system motion in the immediate vicinity of the sliding surface. The auxiliary neural network approximates the corrective control signal required to smooth out the high-frequency jitter effect near the sliding surface.In the course of the study a quad-copter model was designed in the MATLAB environment according to the dynamic equations as well as a controller for three angles (roll, pitch and yaw). The controller consists of a neural network for approximating the main control signals and three neural networks for approximating corrective control signals (one per the axis). Environmental perturbations are involved in model.Based on the system behavior simulation the effectiveness of the proposed control method is shown. Each of the orientation angles (roll, pitch and yaw) follows the desired trajectory with high accuracy. The stability of the system motion in the sliding surface vicinity is proved by Lyapunov method. The simulation results of the neural network controller and a quad-copter dynamic model in the MATLAB environment allow us to draw conclusion that the proposed control method ensures the stable motion along a given trajectory even despite environmental perturbations.

To provide a good deal of manufacturing processes, is used a compressed air, which is produced by compressors of various types, including turbochargers. In highlands, the turbocharger operation is characterized by the fact that the actual performance of the turbochargers differ significantly from the certified values, and the compressed air parameters do not always guarantee the smooth and efficient functioning of using equipment. The conducted theoretical and experimental studies have found out that the highland has impact on the probability of emerging surge. The paper proposes a method to determine a performance margin, which can reduce the overcapacity, i.e., to bring the operating point to the border zone of the surge without opening the anti-surge valve.The paper presents research results of the turbochargers of the type 4CI 425MX4, a series of "CENTAC" manufactured by INGERSOL – RAND, made under production-line conditions in the highland under severe weather conditions.A boundary position of the surge can significantly vary depending on the atmospheric air condition (pressure, temperature, humidity). Knowing the current position of the surge zone and the operating point of the compressor it is possible to regulate the compressor capacity so that, when moving the operating point in the area of low consumption, to provide maximum approximation of the operating point to the border zone of the surge without opening the anti-surge valve. The performance margin relative to the border of surge margin sets the lower limit of regulation and its choice depends on the speed of the operating point movement towards reducing consumption.A reliably determined starting point of the unstable turbocharger operation is an important component to maintain the reliable operation of the air-compressed installations. As follows from the data in the article, the borders of the starting surge and the line of the maximum acceleration of the operating point movement towards surge with decreasing density of the intake air are moved to the left of the operating point, and the value of surge margin increases. The turbocharger stability in highland conditions, when moving the operating point in the area of low consumption is increased.

The product geometry is a fundamental constructive property that has a strong impact on the basic design choices of the assembly process: the product assembly flotation and decomposition into assembly units. The assembly process must be mounted so that the previously set components and elements of technological system could not create geometric obstacles for the main and auxiliary working moves. The paper considers mathematical modelling methods of geometric constraints and restrictions in computer-aided design systems.Publications, about computer-aided design propose numerous varieties of the so-called direct modelling method for geometric obstacles. The principle of this method is to verify the intersection of the geometric model of a mobile object with a static fragment when the first moves along the chosen straight –line (most often) trajectory.It turned out that even in the best version, the direct method is computationally very expensive for products of medium complexity, consisting of several dozen components. Therefore, it is important and urgent to determine the minimum number of geometric verifications, the results of which can be used to synthesize the correct design choices: the assembly flotation and product decomposition into assembly units.The paper proposes a theoretical-lattice formalization of the geometric obstacle of the product. It is shown that the aggregate of all constructive fragments that are assembled independently and do not contain geometric obstacles form a closed algebraic structure that is a lattice. A theorem on d-elements is proved. This theorem allows us to solve the problem of geometric obstacle by cost-conscious algebraic methods. The paper offers three ways for lattice generation: analysis of anti-chains "top-down", lattice reconstruction using a set of generative elements, and probabilistic conclusion based on the Bayesian networks of confidence.

Servo pneumatic and / or hydraulic drives are widely used in modern engineering and process control. The efficiency of using pneumatic / hydraulic drives depends on their parameters and characteristics. To select the optimal drive parameters, various methods are used, based on finding the minimum of the target (target or criteria) function.The objective of this paper was to apply one crucial criterion (target function) that provides determination of optimal parameters of the pneumatic / hydraulic drive with the translational motion of the end-effector as well as its use in the synthesis of the servo pneumatic cylinder. The article shows the form of the target function representing a set of drive parameters that do not have direct relationships with each other in a dimensionless form for the pneumatic / hydraulic drive with the translational motion of the end-effector. To calculate the parameters of the servo drive close to the optimal ones, a two-criteria LPτ search was used. As criteria, were used the decisive criterion - the proposed target function, and the power developed by the actuator of the pneumatic / hydraulic drive, which were presented in a dimensionless form. It is shown that the criterion for solution optimality is the minimum distance of the selected point in the space of the normalized criteria from the origin. This point was determined. In addition to the proposed criteria, non-formalised requirements were taken into account: actual and mass-produced components of drive, in terms of which its parameters close to the optimal ones were determined, and the maximum relative error of the obtained useful power value of the servo pneumatic drive was estimated. The paper presents design features of two types of the servo pneumatic drive created, taking into account the proposed target function, implemented according to the schemes "hidden" and "spaced apart". The experimental static characteristic of the servo pneumatic drive is presented. Based on the results the following conclusions were drawn. The proposed target function can be used in the synthesis of servo pneumatic / hydraulic drives with translational motion of the end-effector using genetic algorithms. The useful power of the pneumatic cylinder, obtained during its synthesis, differs from the optimal value by 1.92%. Tests of the prototype of this pneumatic cylinder confirm that its use is expedient.

The paper demonstrates the role of mathematical modeling in thermal design at different stages of spacecraft development. It analyses the current state of the issue and the approach used to solve this problem in the aerospace industry. The paper suggests using the assembly finite elements models (AFEM) for detailed thermal mathematical models (DTMM) at the stages of conceptual design, production of technical documentation, and technology groundwork. It shows advantages of the proposed approach such as an increased productivity, a possibility of real-time correction of the thermal models and their reuse when designing the next generation of products or upgrading. There are the ways of creating finite element models of assemblies and their applicability in matters of a descending, ascending and combined thermal design styles. A honeycomb panel «+ Z», a part of the construction of small spacecraft "AIST-2D", is used, as an example, to consider the process of creating the assembly finite element model (AFEM) in the software package Siemens NX.During the AFEM application tests when building the detailed thermal mathematical models of small spacecraft "AIST" and "AICT-2D" was revealed an essential feature inherent in the proposed technology that is a need to use thermal couplings because the meshes of various components do not involve a mate "node to node ".A test problem has been solved by analytical and numerical methods in order to verify the proper use of thermal couplings when building the detailed thermal mathematical models of small spacecraft. The effectiveness of the proposed method has been estimated in terms of saving time to create DTMM, with the benefit of hindsight of its use as applied to the functioning and newly developed small spacecraft.

The traditional approaches to decoding shortened block codes are the padding of received codeword with zeros or correction of the syndrome polynomial values. Such approaches make stream-oriented decoding of continuous input data stream impossible. The paper offers a new technique for decoding the shortened Reed-Solomon codes. Its hardware implementation allows us to provide stream processing, reduce latency in clock cycles, and decrease a required quantity of hardware resources as compared to decoder implementation with padding of received packet with zeros. A distinctive feature of the proposed technique is that the decoder processes a stream of code words of different lengths without changing their structure and insertion of additional delays and that it is possible to use the modules of existing Reed-Solomon decoders for full codeword length. To enable this, a notion of error locator corrector for shortened code is introduced and a technique of their calculation is offered. Error locator correctors are calculated during the reception of a codeword in parallel to syndrome polynomial calculation. Their values allow us to modify the polynomial values of locators and errors at the output of the key equation solver. The paper considers a shortened code decoder that is implemented on the full code decoder modules based on Berlekamp-Massey algorithm, describes architecture of additional modules and required modifications of the algorithm. It shows the way to save hardware resources by using the multipliers in Berlekemp-Massey key equation solver to correct values. The Altera FPGA-based decoder has been tested in and compared to the Reed-Solomon II decoder IP from Altera.

The paper presents the ways to eliminate shrinkage defects of casting nature. These techniques are, primarily, technological overlaps, risers and refrigerators. The paper shows that these methods are based on the known principle of feeding, according to which the upper layers of the casting is the risers for the underlying layers. This provides directional solidification of casting.The paper describes the additive technologies that solve problems, which are unobtainable for conventional casting technologies. It shows that the thin horizontal layers form a casting configuration sequentially. Here is realized another principle of feeding that is formulated as follows: each layer feeds itself. There is no difficulty to eliminate shrinkage defects in thin horizontal layers.However, high cost of raw materials and equipment and low productivity disallow wide introduction of additive technologies to manufacture castings.One solution to this problem, which is offered to-date is to create hybrid-manufacturing processes that combine both additive and traditional manufacturing techniques of casting.Traditional manufacturing techniques of castings are macro-level technologies while the additive technology is a micro level. Hybrid technologies, which are in intermediate position, can be attributed to a meso-level of the review of processes occurring in the liquid melt and mold.The paper has shown that the casting techniques that provide layer-by-layer filling of liquid melt in the mold and (or) layer-by-layer solidification of liquid melt in the mold can serve as one of the examples of hybrid technology in foundry.The paper analyses some of the patents related to the group of "casting ingots of two or more different melts, i.e. multilayer » (B22D7 / 02). It conducts an analysis of the patent developed in BMSTU. The main conclusions are as follows:1. At present, there is a base created for a successful development of hybrid technology in the foundry industry.2. Hybrid technology allows the casting production for a period of transition (the period of changing traditional technology) to provide a new quality of castings.

The turbulent-flow throttles are used in pneumatic systems and gas-supply ones to restrict or measure gas mass flow. It is customary to install the throttles in joints of pipelines (in teejoints and cross tees) or in joints of pipelines with pneumatic automation devices Presently, in designing the pneumatic systems and gas-supply ones a gas mass flow through a throttle is calculated by a known equation derived from the Saint-Venant-Vantсel formula for the adiabatic flow of ideal gas through a nozzle from an unrestrictedly high capacity tank. Neglect of gas velocity at the throttle inlet is one of the assumptions taken in the development of the above equation. As may be seen in practice, in actual systems the diameters of the throttle and the pipe wherein it is mounted can be commensurable. Neglect of the inlet velocity therewith can result in an error when determining the required throttle diameter in design calculation and a flow rate in checking calculation, as well as when measuring a flow rate in the course of the test. The theoretical study has revealed that the flow velocity at the throttle inlet is responsible for two parameter values: the outlet flow velocity and the critical pressure ratio, which in turn determine the gas mass flow value. To calculate the gas mass flow, the dependencies are given in the paper, which allow taking into account the flow rate at the throttle inlet. The analysis of obtained dependencies has revealed that the degree of influence of inlet flow rate upon the mass flow is defined by two parameters: pressure ratio at the throttle and open area ratio of the throttle and the pipe wherein it is mounted. An analytical investigation has been pursued to evaluate the extent to which the gas mass flow through the throttle is affected by the inlet flow rate. The findings of the investigation and the indications for using the present dependencies are given in this paper. By and large the investigation allowed the conclusion that the inlet flow rate must be taken into account when calculating the gas mass flow through the throttles of pneumatic systems and gas supply systems.

Modern methods to solve the practical problems related to the information security system design in multipurpose distributed systems often use optimization models. The paper formulates a problem statement of bilinear Boolean programming with the quality score that determines the level of the system security to select classes of protected objects in distributed systems and allocate databases in these objects. Restrictions specify the maximum cost of protection and the recommended amount of data stored in the object. To solve this problem, using the algorithms of discrete programming is possible, but the accurate algorithms, generally, are exponentially timeconsuming. To find a solution the paper proposes to interpret this problem as a problem of two players with non-conflicting interests. The first player is responsible for the assignment of security classes for the system objects, and the second player is responsible for the distribution of databases between the objects. To find solutions the use of a Nash equilibrium criterion is offered.To find the equilibrium solution is developed an algorithm and are proved its convergence, and the fact that it really allows us to obtain the Nash equilibrium position. Using the problem-solving approach related to reducing the original optimization problem to a two-player game with nonconflicting interests allowed a decreasing dimension of the original problem, because at each step of the algorithm is solved the problem of discrete optimization of a smaller dimension than the original problem of Boolean programming.The paper presents results of solving the problem, as well as research results on the time complexity of represented algorithms. It conducts a comparative analysis of the two approaches: an approach based on solving a discrete optimization problem and an approach based on reducing the problem to a two-player game with non-conflicting interests. An approach based on reducing the initial problem to a game, allowed us to decrease solution time significantly, by 2-3 orders, while, in general, the reached value was the same as in the original problem of Boolean programming.

This paper proposes a method to calculate the splitting of natural frequency of the shell of hemispherical resonator gyro. (HRG). The paper considers splitting that arises from the small defect of the middle surface, which makes the resonator different from the rotary shell. The presented method is a combination of the perturbation method and the finite element method. The method allows us to find the frequency splitting caused by defects in shape, arbitrary distributed in the circumferential direction. This is achieved by calculating the perturbations of multiple natural frequencies of the second and higher orders. The proposed method allows us to calculate the splitting of multiple frequencies for the shell with the meridian of arbitrary shape.A developed finite element is an annular element of the shell and has two nodes. Projections of movements are used on the axis of the global cylindrical system of coordinates, as the unknown. To approximate the movements are used polynomials of the second degree. Within the finite element the geometric characteristics are arranged in a series according to the small parameter of perturbations of the middle surface geometry.Movements on the final element are arranged in series according to the small parameter, and in a series according to circumferential angle. With computer used to implement the method, three-dimensional arrays are used to store the perturbed quantities. This allows the use of regular expressions for the mass and stiffness matrices, when building the finite element, instead of analytic dependencies for each perturbation of these matrices of the required order with desirable mathematical operations redefined in accordance with the perturbation method.As a test task, is calculated frequency splitting of non-circular cylindrical resonator with Navier boundary conditions. The discrepancy between the results and semi-analytic solution to this problem is less than 1%. For a cylindrical shell is made a comparison of results with solution in ANSYS commercial complex - a difference is less than 1%. For a hemispherical shell was found the frequency splitting. The comparison has shown that a discrepancy between the results and ANSYS solution is less than 1%. The solution of this problem allows us to estimate further a mutual influence of defects of different nature (shape, thickness, density, modulus of elasticity, etc.) on splitting the frequency of the HRG. This is an urgent problem in terms of balancing the HRG resonators.

The objects of research are undirected graphs. The paper considers a problem of their isomorphism. A literature analysis of its solution, has shown that there is no way to define a complete graph invariant in the form of unique structural characteristics of each its vertex, which has a computational complexity of definition better than О (n 4 ).The work objective is to provide the characteristics of the graph structure, which could be used to solve the problem of their isomorphism for a time better than О (n 4 ). As such characteristics, the paper proposes to use the set of codes of tree roots of all the shortest - in terms of the number of edges - paths from each vertex to the others, uniquely defining the structure of each tree. It proves the theorem that it is possible to reduce the problem of isomorphism of the undirected graphs to the isomorphism problem of their splitting into the trees of all the shortest - in terms of the number of edges - paths of each vertex to the others. An algorithm to construct the shortest paths from each vertex to all others and to compute codes of their vertices has been developed. As the latter, are used Aho-codes, which find application in recognising the isomorphism of trees. The computational complexity to obtain structural characteristics of vertices has been estimated to be about О (n 3 ).The pilot studies involved the full-scale experiment using the developed complex programmes to generate raw data, i.e. analytic representation of the graph with the number of vertices equal to 1200, and a programme to provide codes of the tree roots. To have an estimate of - "the worst" in terms of time - complexity of expansion algorithm of graphs into trees of the shortest paths and define the codes of their roots has been an experimentally studied how the number of tree vertices depends on the graph density. For the worst case was obtained a dependence of the number of tree vertices on the number of graph vertices, approximated by the quadratic function, which is consistent with the theoretical estimates. The experimental results of studies, in general, prove those of theoretical estimates.

Prospects for space robotics concern both the development of used prototypes to extend the capabilities and the creation of new classes of systems, the operating analogues of which are, currently, unavailable. Thus, a uniqueness of the objects of space robotics, extreme operating conditions, difficulty in full-scale ground work and tests define a variety of design solutions and a wide scope of issues for further theoretical and experimental studies. The paper highlights the tasks successfully solved up to date, involving the space robotics equipment that was used in orbital environment, those of currently solved, involving the robotics equipment that is in use, and the long-term objectives, following from the logic of the space technology development to define the ways of its further development and require a development and creation of new equipment of space robotics. Thus, the development trends of space robotics are largely defined by its history of development, on the one hand, and by a growing demand for the robotic service as applied to the promising objects of space technology, on the other one. The paper considers the trends of space robotics development, which are a consequence of the natural logic of its development and are determined by a demand for advanced objects of space technology in robotic servicing. Highlights the most important elements of a design concept and the creating and operating features of the multipurpose extendable space systems, including those, which have no analogues and prototypes, are rolled into one demand for automation, and associated with their creation, operation, and problems of utilization. The concept of assembly and service autonomous robotic space modules has been under consideration. Within the orbital assembly procedure, the typical dynamic modes, relevant in terms of practical implementation of controlled movement are highlighted.

The article presents a statement of technique to research performances of multi-channel combo standalone information systems with positional analyzers of the signal states at the channel outputs. In most cases, in considered multi-channel systems there has been impossible to coincide in time the random moments of signals coming from the objects through various channels in all ways of encounter environment and conditions of practical application. The analyzer makes decision on the signal using the discrete operations on the quantized signals of the certain duration from the channel outputs. The analyzer performance is described by a set of Boolean algebra functions defined for all possible states of the signals at the outputs of the channels, and in the general case is specified in a perfect disjunctive normal form. To determine the validity or falsity of functions of the algebra of logics, which are calculated statements concerning the available or unavailable useful signal at the system input, on the authority of the Poretsky’s theorem and the theory of coincidence in time of the random pulse flow of the channels response because of uncorrelated and correlated noise, are obtained dependences to calculate the probabilities of false alarms and omissions of the signals in discrete combined systems. It is shown that the flows of false alarms because of noise at the channel outputs in the system are Poisson streams. On the basis of the ordinary Poisson flows the paper justifies the relationships for calculating the false alarms of the system with uncorrelated and correlated noise in the channels. The paper also justifies the relationships for performance of multichannel combined systems with positional analyzers of the channels states. Based on the obtained relationships was calculated the average coincidence frequency of the extended pulses of the channel response in a dualchannel system, depending on the noise cross-correlation coefficient with different extended pulse durations and relative response thresholds in the channels. The impact of cross-correlation noise has been analysed. The obtained results enable us to examine the performance of the multichannel autonomous information systems with positional analyzers of the signal states at the outputs of channels operating under uncorrelated and correlated noise.

Cavitation properties of liquid must be taken into consideration in the engineering design of hydraulic machines and hydro devices when there is a possibility that in their operation an absolute pressure in the liquid drops below atmospheric one, and for a certain time the liquid is in depression state. Cold boiling, which occurs at a comparatively low temperature under a reduced absolute pressure within or on the surface of the liquid is regarded as hydrostatic cavitation if the liquid is stationary or as hydrodynamic cavitation, if the liquid falls into conditions when in the flow cross-section there is a sharply increasing dynamic pressure and a dropping absolute pressure.In accordance with the theory of cavitation, the first phase of cavitation occurs when the absolute pressure of the degassed liquid drops to the saturated vapour pressure, and the air dissolved in the liquid, leaving the intermolecular space, is converted into micro-bubbles of combined air and becomes a generator of cavitation “nuclei”. A quantitative estimate of the minimum allowable absolute pressure in a real, fully or partially degassed liquid at which a hydrostatic cavitation occurs is of practical interest.Since the pressure of saturated vapour of a liquid is, to a certain extent, related to the forces of intermolecular interaction, it is necessary to have information on the cavitation properties of technical solutions, including air solution in a liquid, as a solute may weaken intermolecular bonds and affect the pressure value of the saturated solvent vapour. In the experiment to carry out vacuum degassing of liquids was used a hydraulic air driven vacuum pump.The paper presents hydrostatic and hydrodynamic degassing liquid processes used in the experiment.The experimental studies of the cavitation properties of technical liquids (sea and distilled water, saturated NaCl solution, and pure glycerol and as a 49/51% solution in water, mineral oil and jet fuel) enabled us to have an quantitative estimate of the absolute pressure in the allowable technical liquids and solutions, its dependence on the saturated vapour pressure, as well as to define the influence of a degree of the hydrodynamic degassing of liquid and the amount of its solute on the liquid tensile strength.The paper gives a comparative assessment of cavitation properties of liquids. When studying the cavitation properties of solutions it has been found that a level of the allowable absolute pressure in a solution exceeds that of in the solvent. It is suggested that the dissolved solid, liquid or gaseous substances weaken the intermolecular bonds of the solvent and increase the pressure of its saturated vapour.

The objective is to put forward a proposal to divide the internal shrinkage defects into the dimensional levels according to defects of certain size and shape.The paper presents the terminology used to describe the internal shrinkage defects in the casting and shows its flaws. These include the lack of well-defined threshold size values and shape of defects. It is shown that in describing defects their sizes and shape are defined qualitatively rather than quantitatively. And it is noted that division of defects into pores and shells is based on the morphological characters.The paper notes that a distinct difference between defects is necessary because of different methods of their elimination from the casting body.The paper presents an overview of control methods to determine the defects of the shrinkage nature in castings. These are methods of destructive and non-destructive testing, such as Xrays, tomography, and metallography. The paper also shows advantages and disadvantages of the considered methods of control. Based on the control method capacities it offers to divide the shrinkage defects into the three dimensional levels.To estimate the shape of defects the paper suggests a new option, that is a shape criterion. By the example of the typical defects of each dimensional level are defined the threshold values of the shape criterion.The paper discusses the basic techniques to estimate the porosity and offers a relationship between the defects of different dimensional levels and a porosity score and percent. It shows that the transition from a dimensional level to another one is in line with not only increasing pore size, but also with a significant deterioration of the mechanical properties of castings.The main conclusions are as follows:1. At present, there is no single unambiguous classification of casting shrinkage defects in the technical literature.2. As follows from the analysis of the classifications of shrinkage defects, their control and estimation methods that there are three dimensional levels proposed, with each one corresponding to defects of a certain size and shape and methods of their control.3. A common approach proposed to estimate the castings porosity for various control methods is to define a percent of porosity.

The paper considers a task of generating the requirements and creating a calibration target for automated microscopy systems (AMS) of biomedical specimens to provide the invariance of algorithms and software to the hardware configuration. The required number of color fields of the calibration target and their color coordinates are mostly determined by the color correction method, for which coefficients of the equations are estimated during the calibration process. The paper analyses existing color calibration techniques for digital imaging systems using an optical microscope and shows that there is a lack of published results of comparative studies to demonstrate a particular useful color correction method for microscopic images. A comparative study of ten image color correction methods in RGB space using polynomials and combinations of color coordinate of different orders was carried out. The method of conditioned least squares to estimate the coefficients in the color correction equations using captured images of 217 color fields of the calibration target Kodak Q60-E3 was applied. The regularization parameter in this method was chosen experimentally. It was demonstrated that the best color correction quality characteristics are provided by the method that uses a combination of color coordinates of the 3rd order. The study of the influence of the number and the set of color fields included in calibration target on color correction quality for microscopic images was performed. Six train sets containing 30, 35, 40, 50, 60 and 80 color fields, and test set of 47 color fields not included in any of the train sets were formed. It was found out that the train set of 60 color fields minimizes the color correction error values for both operating modes of digital camera: using "default" color settings and with automatic white balance. At the same time it was established that the use of color fields from the widely used now Kodak Q60-E3 target does not allow achieving values of microscopic images color correction errors below the color difference level of visibility for the human eye. The conclusion is that there is a need in development of specialized calibration target for AMS of biomedical specimens.

In this paper, we suggest to use hybrid approach to time series forecasting problem. In first part of paper, we create a literature review of time series forecasting methods based on hybrid neural networks and neuro-fuzzy approaches. Hybrid neural networks especially effective for specific types of applications such as forecasting or classification problem, in contrast to traditional monolithic neural networks. These classes of problems include problems with different characteristics in different modules. The main part of paper create a detailed overview of hybrid networks benefits, its architectures and performance under traditional neural networks. Hybrid neural networks models for time series forecasting are discussed in the paper. Experiments with modular neural networks are given.

The paper studies the physical relationship between the main objects of the magnetic field in a continuous medium with magnetization effects. Consistently considers the following hypotheses: a hypothesis of the primacy and the physical reality of the magnetization vector field environment, a similar hypothesis about the real existence of Ampere currents (molecular currents, magnetization currents), a hypothesis of a magnetic dipole moment of the medium volume element in view of bulk density of electric currents in this volume. A more rigorous derivation of the basic differential equations of magnetostatics from the Biot-Savart-Laplace equation is proposed.The well-known works justifying basic equations of magnetostatics use a procedure wherein when proving the local differential ratio is used a transformation of some volume integral to the surface integral bounding this volume. Thus, there is a specific way to select a closed surface that is either a surface in a vacuum (beyond the medium volume under consideration), or a surface of the conductor (a normal component of currents to the surface, here, becomes zero). In the paper the control surface is arbitrarily carried out within the volume of the medium under consideration, thereby leading to the mathematically sound result.The paper analyzes the hypotheses listed above. The main feature of analysis is a succesively using concept of bilateralism surface bounding the medium volume of the arbitrary finite dimensions. The analysis allowed us to reveal the physical adequacy of the considered hypotheses, derive the appropriate differential equations for the basic vector fields of magnetostatics and obtain a new condition. The resulting condition for the closedness of magnetization currents is recorded in entire compliance with the well-known Gauss electrostatic law, which avoids the need for additional, but not always reasonable assumptions.

The paper discusses a specific fuel rate in combined heat and electricity production using CHP technology. There are two objectives for calculation of specific fuel rate: a) CHP technical efficiency estimate, b) increasing CHP competitiveness at electricity and district heat markets. Currently, development of a number of thermo-dynamical methods of calculation solves the first problem while to solve the second one there is a number of developed economical methods of calculation. In Russia despite a decade of the wholesale electricity market progress the CHP market offers are still tightly connected with technical efficiency rate. To estimate the technical efficiency rate is widely used the least effective thermo-dynamical method – so called “physical” method”. The paper formulates a problem statement that is the specific fuel rate calculation and reviews the most widely applied methods. The review consists of two parts: in the first the Russian methods are discussed, and in the second one the methods widely used in the countries with highly developed electricity and district heat markets. A new thermo-dynamical method to calculate the specific fuel rate is introduced, which uses the linear characteristic curves of a steam turbine. The developed method allows us to take into consideration the energy inequality of the CHP products. Another advantages of this new method are calculation simplicity and small number of input data. To compare the effectiveness of different methods were introduced comparison rules and also calculations were performed. The comparison of thermo-dynamical methods shows that the most effective methods are an exergy method and also the method that takes into consideration the reduced generation of electricity (work method). Calculation complexity and large number of input data are main disadvantages of these methods. The comparison of economical methods shows that the most effective from stated point of view are a benefit and risk distribution method and a method of the alternative way of heat production. A drawback of these methods is that the volatility of market prices is raised with their wide application. The paper separately discusses results of calculations by “physical” method. It comes to conclusion that application of this the least effective thermo-dynamical method to calculate the cost of CHP products puts the brakes on the progress of market relations in electricity and district heat.

This work is concerned with analysis of cross-plane thermal transfer in nanofilms.The paper presents a developed general model of phonon radiation transfer (EPRT) based on the Boltzmann transport equation. The EPRT model assumes that the thermal transfer inside a dielectric or metal medium between two metal walls is maintained at different temperatures. These walls are like heat reservoirs; their surfaces are blackbodies. The paper first presents a model of the phonon radiation transfer of the absolute blackbodies in a wide range of temperatures where a model of the ballistic thermal transfer is applicable. It conducts a comparative analysis between phonon radiation transfer and electromagnetic radiation.The basic equation is a formula to calculate a phonon radiation intensity of the absolute blackbody depending on the temperature. Therefore, the formula for the total intensity of phonons is similar to the Stefan-Boltzmann law. The main difference of phonon radiation transfer is that a value of the phonon Stefan-Boltzmann constant is affected by temperature and properties of materials (average acoustic waves in solid bodies and Debye temperature). This can be seen from the curves for Si, Ge, and Diamond.The paper presents a received analytical equation for effective thermal conductivity using a heat flux in a cross-plane direction. The results obtained show the size and temperature dependences of the effective thermal conductivity of silicon, germanium and diamond nanofilms for the ballistic transport in the cross-plane direction. Finally, the paper compares the calculated results with those of available models of different foreign authors, which are in good compliance.

Laser gas analysers are the most promising for the rapid quantitative analysis of gaseous air pollution. A laser gas analysis problem is that there are instable results in reconstruction of gas mixture components concentration under real noise in the recorded laser signal. This necessitates using the special processing algorithms. When reconstructing the quantitative composition of multi-component gas mixtures from the multispectral laser measurements are efficiently used methods such as Tikhonov regularization, quasi-solution search, and finding of Bayesian estimators. These methods enable using the single measurement results to determine the quantitative composition of gas mixtures under measurement noise. In remote sensing the stationary gas formations or in laboratory analysis of the previously selected (when the gas mixture is stationary) air samples the reconstruction procedures under measurement noise of gas concentrations in multicomponent mixtures can be much simpler. The paper considers a problem of multispectral laser analysis of stationary gas mixtures for which it is possible to conduct a series of measurements. With noise overshoots in the recorded laser signal (and, consequently, overshoots of gas concentrations determined by a single measurement) must be used stable (robust) estimation techniques for substantial reducing an impact of the overshoots on the estimate of required parameters. The paper proposes the Huber method to determine gas concentrations in multicomponent mixtures under signal overshoot. To estimate the value of Huber parameter and the efficiency of Huber's method to find the stable estimates of gas concentrations in multicomponent stationary mixtures from the laser measurements the mathematical modelling was conducted. Science & Education of the Bauman MSTU 108 The mathematical modelling results show that despite the considerable difference among the errors of the mixture gas components themselves a character of the error dependence on the Huber parameter for all gas components is the same. When an optimal Huber parameter (~ 0.00025 - 0.000025 in case of the specific mixture used in mathematical modelling) is selected the measurement errors of concentrations for all gas components are much smaller than the measurement errors when using the standard method of least squares

Currently, issues on processing of large data volumes are of great importance. Initially, the Andrews plots have been proposed to show multidimensional statistics on the plane. But as the Andrews plots retain information on the average values of the represented values, distances, and dispersion, the distances between the plots linearly indicate distances between the data points, and it becomes possible to use the plots under consideration for the graphical representation of multi-dimensional data of various kinds. The paper analyses a diversity of various mathematical apparatus for Andrews plotting to visualize multi-dimensional data.The first section provides basic information about the Andrews plots, as well as about a test set of multidimensional data in Iris Fischer’s literature. Analysis of the Andrews plot properties shows that they provide a limitlessly many one-dimensional projections on the vectors and, furthermore, the plots, which are nearer to each other, correspond to nearly points. All this makes it possible to use the plots under consideration for multi-dimensional data representation. The paper considers the Andrews plot formation based on Fourier transform functions, and from the analysis results of plotting based on a set of the test, it draws a conclusion that in this way it is possible to provide clustering of multidimensional data.The second section of the work deals with research of different ways to modify the Andrews plots in order to improve the perception of the graphical representation of multidimensional data. Different variants of the Andrews plot projections on the coordinate planes and arbitrary subspaces are considered. In addition, the paper studies an effect of the Andrews plot scaling on the visual perception of multidimensional data.The paper’s third section describes Andrews plotting based on different polynomials, in particular, Chebyshev and Legendre polynomials. It is shown that the resulting image is well correlated with the original point diagram and the Andrews plots based on the Fourier transform. This allows us to draw a conclusion that the Andrews plots based on the polynomial functions can be used for multidimensional data analysis.The fourth section studies wavelets as a basis for Andrews plotting. It is noted that wavelets have some advantages as compared to the Fourier series. In many areas of the signal analysis a Fourier transform is used for measuring the frequency characteristics of the signal over the entire area. The wavelet transform, on the contrary, is used when it is necessary to measure frequency characteristics in time-localized clusters. Fourier and wavelet transforms are complementary. Fourier transform yields an average frequency with respect to time, and the wavelet transform provides the signal frequency values at any time interval. Based on wavelets Andrews plotting through a set of test data, has shown that it is possible to apply this approach to the graphical representation of multidimensional data.

The study of the processes occurring in the scramjet is an important task. These processes include formation of a hydrogen-air mixture to the combustion chamber scramjet. The experimental study of such processes involves various difficulties. Therefore the use of mathematical models and numerical modeling to analyze such problems is of importance.In this paper we consider the formation of hydrogen-air mixture by injecting hydrogen into concurrent supersonic airflow by the radial pylons arranged in the three-dimensional channel with a central coaxial cylinder. As a basis of the geometric model, a channel of circular cross section is taken, which is a sector in axisymmetric formulation. In the channel pylons are set. The paper considers pylons of two different shapes, as well as two versions of their location in the channel. Pylons are different in height, fastening method, and different flow vortex generators (turbulator), designed to improve the mixing efficiency. The pylon №1 is attached to the channel wall and occupies no more than 1/3 of the channel radius in radial direction. The pylon №2 is located along the entire channel radius and fastened with its one side to the wall of the channel and with another one to the coaxial cylinder extending along the axis of symmetry. Pylons are distinguished by different flow turbulators designed to improve the mixing efficiency. Hydrogen injection is carried out from the pylon surface before a turbulator. Hydrogen injection angle relative to the axis of the channel in the case of the first turbulator arises from its geometry to be 12º, in the case of the second turbulator it is 0º (to reduce losses of the total flow pressure). We study the influence of the geometric shape of the pylons on characteristics of emerging hydrogen-air mixture flow.Research is conducted numerically on the basis of Reynolds equations for a turbulent motion of viscous multicomponent gas with k  turbulence model. The problem is solved on a computational grid of 300 thousand cells with the number of Courant CFL = 1. The equations are discretized by the method of control volume using the schemes of the second order of accuracy.It was shown that changing the geometry of the vortex generator can increase the intensity of mixing, but this decreases the penetration ability of hydrogen because of decreasing injection angle. At the same time, changing the turbulator shape causes deteriorating carburetion. A reduced efficiency of mixing in some areas reaches 37%. An additional turbulator available in the vicinity of the coaxial cylinder does not compensate for the loss of carburetion quality. The total pressure loss decreases when the hydrogen injection occurs at a zero angle to the channel axis.

The objective of this article is to assess the prospects for an increasingly maneuverable reentry vehicle (RV) of class "lifting body". In this regard, a project aerodynamic thermal and ballistic analysis has been conducted and the results have been compared with some well-known projects of the RV of the same class, made both in our country and abroad.The project analysis begins with finding a position of the "lifting body" vehicle in the classification system. Said classification distribution allows correct formulation of requirements for the conceptual structure of an aerospace vehicle at the initial stage of design in terms of system positions, since just the initial phase of the design often determines the success of the whole program.Then the paper compares design characteristics of the RV of class "lifting body" with vehicles such as X-15 rocket plane, the orbiter "Space Shuttle», M2-F2, HL-10, SV-5, and NASP "Hermes". It also gives a comparative estimate of the "lifting body" RV mass in a wide range of dimensions. The paper shows the sustainability of various landing complexes with reference to the Russian experience in developing the RV " Soyuz", and the conditions for using the vehicles of class "lifting body" in space programs.The aerodynamic analysis uses method for the approximate Newtonian theory to calculate aerodynamic characteristics of the perspective RV of class "lifting body" in the hypersonic descent phase. To obtain the desired aerodynamic performance and reduce balancing weight is contemplated a possibility to provide balance by introducing additional boards. The ballistic analysis considers four modes of descent:1. zero roll descent;2. maximum cross-range descent without restriction;3. maximum cross-range descent with restriction of maximum overload and maximum temperature;4. ballistic descent.To calculate the RV ballistic characteristics a system of equations of the vehicle motion in the atmosphere is used. The vehicle was considered as a material point. The roll angle was used as a control parameter. The assigned task was an optimal control. To solve the problem of optimal control was used a method of sequential linearization.The paper presents estimates of temperature for different modes of descent in characteristic points of the RV surface.From the analysis it is clear that the promising RV form of class "lifting body" is a good alternative to the landers of "glide descent", especially for the reentry from lunar and Martian missions. Also a significant increase in cross-range (up to 1500 km, in contrast to the RV "Soyuz" with the cross-range of up to 150 km) allows a virtually infinitely expanding corridor to reentry into atmosphere, thereby making landing possible in almost any point of the European part of the Russian Federation.

The paper considers an approach to analyze a dynamic stability of the drilling process in terms of tool flexibility. The proposed technique takes into consideration a regenerative effect leading to time delay in the dynamic system. This regenerative delay is the main source of arising dynamically unstable machining conditions. The paper describes a principle of emerging self-vibrations while cutting. It mentions the undesirable nature of transverse bending selfvibrations of tool, which cause a decreasing quality of the processed hole surface.The suggested approach consists in building a diagram of the drilling process stability for a tool model allowing only its flexural vibrations. The feature of the study is to describe tool dynamics using a finite element model based on the quadratic approximation of displacements for tool dynamics modeling. The assumption of an axial symmetry of drill geometry was discarded. The reduced model of tool was built taking into account two eigenvectors corresponding to tool bending. This model contains 2 degrees of freedom (DOF), which are, essentially, rotations of a drill tip. The technology of rigid multi-point constraints was used to connect those DOFs with solid finite element nodes. The system of delayed differential equations describing the reduced tool model dynamics was derived to estimate a dynamic stability of the drilling process. The Floquet theory is applied to build a stability diagram as a maximum multiplicator value versus a drill rotation rate. The presented diagram allows us to draw a conclusion that in the wide range of rotation frequencies transverse bending self- vibrations can be excited. The results obtained and the calculation technique may be used to choose the operation modes free from undesirable flexural self-vibrations of tool.The reported study was supported by RFBR within the framework of the research project ” mol_a”№ 14-08-31603 “Development of methods and algorithms for modeling a dynamics of the cutting complex parts”.

The paper describes design issues for MEMS-based pedestrian inertial navigation systems. By now the algorithms to estimate navigation parameters for strap-down inertial navigation systems on the basis of plural observations have been already well developed. At the same time mathematical and software processing of information in the case of pedestrian inertial navigation systems has its specificity, due to the peculiarities of their functioning and exploitation. Therefore, there is an urgent task to enhance existing fusion algorithms for use in pedestrian navigation systems. For this purpose the article analyzes the characteristics of the hardware composition and configuration of existing systems of this class. The paper shows advantages of various technical solutions. Relying on their main features it justifies a choice of the navigation system architecture and hardware composition enabling improvement of the estimation accuracy of user position as compared to the systems using only inertial sensors. The next point concerns the development of algorithms for complex processing of heterogeneous information. To increase an accuracy of the free running pedestrian inertial navigation system we propose an adaptive algorithm for joint processing of heterogeneous information based on the fusion of inertial info rmation with magnetometer measurements using EKF approach. Modeling of the algorithm was carried out using a specially developed functional prototype of pedestrian inertial navigation system, implemented as a hardware/software complex in Matlab environment. The functional prototype tests of the developed system demonstrated an improvement of the navigation parameters estimation compared to the systems based on inertial sensors only. It enables to draw a conclusion that the synthesized algorithm provides satisfactory accuracy for calculating the trajectory of motion even when using low-grade inertial MEMS sensors. The developed algorithm can be implemented in the individual navigation equipment designed to solve practical tasks requiring autonomous positioning.

The aim of this work is to enhance competitiveness of hotel complex management in the hotel service market of the state of Côte d'Ivoire.The objectives of this study are:1) producing a model of oligopoly market of hotel services based on marketing research;2) synthesis of the conflict-optimum management method of a hotel complex using the model of oligopoly market of hotel services;3) study of issues on competitiveness enhancement of running hotel complex in the market of oligopoly under counter-conditions of other hotel complexes.To obtain the result the paper offers to use techniques of classical and modern theory of management, namely methods of the theory of optimal management of multi-object multicriteria systems, methods of game theory, methods of system analysis, operations research and decision-making.The paper proposes a model of the oligopoly market for interaction of hotels in the hospitality services in Stackelberg’s form in which, as the "governing" parameters, a hotel complex has the accommodation cost in the selected category and the advertising cost. Monthly income of the hotel complex is proposed as an indicator of the efficiency. Evaluation of success in the market is based on the indicator of competitiveness.To solve the problem of multi-criteria optimization the paper offers a method of conflictoptimum competitiveness management of hotel complexes. It considers a model example of the interaction between two complexes in the market of duopoly.It is concluded that in the case of a saturated demand for the services of hotel complexes, there is a guaranteed Nash solution, which ensures a certain profit regardless of the actions of another hotel complex. In the case of unsaturated demand (lack of customers) in the market there is no guaranteed solution, which is a prerequisite for entry into agreement between the market players.The model obtained can be useful for observing trends in the market of hotel services.

This paper proposes a new algorithm for community differentiation in social graphs, which uses information both on the graph structure and on the vertices. We consider user's ego-network i.e. his friends, with no himself, where each vertex has a set of features such as details on a workplace, institution, etc. The task is to determine missing or unspecified features of the vertices, based on their neighbors' features, and use these features to differentiate the communities in the social graph. Two vertices are believed to belong to the same community if they have a common feature. A hypothesis has been put forward that if most neighbors of a vertex have a common feature, there is a good probability that the vertex has this feature as well. The proposed algorithm is iterative and updates features of vertices, based on its neighbors, according to the hypothesis. Share of neighbors that form a majority is specified by the algorithm parameter. Complexity of single iteration depends linearly on the number of edges in the graph.To assess the quality of clustering three normalized metrics were used, namely: expected density, silhouette index, and Hubert's Gamma Statistic. The paper describes a method for test sampling of 2.000 graphs of the user's social network \VKontakte". The API requests addressed \VKontakte" and parsing HTML-pages of user's profiles and search results provided crawling. Information on user's group membership, secondary and higher education, and workplace was used as features. To store data the PostgreSQL DBMS was used, and the gexf format was used for data processing. For the test sample, metrics for several values of algorithm parameter were estimated: the value of index silhouettes was low (0.14-0.20), but within the normal range; the value of expected density was high, i.e. 1.17-1.52; the value of Hubert's gamma statistic was 0.94-0.95 that is close to the maximum. The number of vertices with no features was calculated before and after applying the algorithm. With two-third of vertices before using the algorithm their number has fallen to 25-64% depending on algorithm parameter after applying it. The proposed algorithm can be used for clustering the social graphs, but it should be modified to differentiate overlapping communities.

The article proposes a technique to develop mathematical models (MM) of elements of the three-dimensional (3D) mechanical systems for universal simulation software systems that allow us automatically generate the MM of a system based on MM elements and their connections. The technique is based on the MM of 3 D body. Linear and angular velocities are used as the main phase variables (unknown in the MM of the system), linear and angular movements are used as the additional ones, the latter being defined by the normalized quaternions that have computational advantages over turning angles.The paper has considered equations of dynamics, formulas of transition from the global coordinate system to the local one and vice versa. A spherical movable joint is presented as an example of the interaction element between the bodies. The paper shows the MM equivalent circuits of a body and a spherical joint. Such a representation, as the equivalent circuit, automatically enables us to obtain topological equations of the system. Various options to build equations of the joint and advices for their practical use are given.

The paper offers a volumetric hydraulic drive structure consisting of an unregulated pump, hydraulic motor, and energy accumulation block with pneumatic-hydraulic accumulator (PHA). Drive control is provided through frequency modification of current arriving at the asynchronous electric drive (AED) from the frequency changer.The paper describes drive advantages when the energy accumulation block is set to allow power accumulation both from the AED and in recuperation regimes with moving outlet drive link with assisting loads. It offers simulation models and computer programmes to analyze a non-stationary movement of the outlet link of volumetric hydraulic drive with frequency control (VHD-FC) with hydraulic motor power supplied from the PHA. The paper examines acceleration regimes of motor axis under different loads and presents PHA energy characteristics and algorithms to find desirable operational non-displaced and constructional accumulator capacities that provide motor outlet link acceleration up to the necessary speed. It presents graphs to show changing motor axis angle speed and PHA-displaced fluid volume as well as energy and PHA power during its discharge versus acceleration time of the motor axis. These dependences are obtained through varying different parameters of the system, namely: inertia, viscous friction, constant load moment, and volumetric displacement.The paper shows that decrease of inertia load and use of hydraulic motor with high volume constants result in the most essentially reduced acceleration time. Setting the PHA allows more than 2.5 times decreasing acceleration time of the motor axis. At the same time, because of the evidently complicated VHD-FC, taking decision on the sound PHA design and parameters must be based on the integration analysis of requirements. These requirements concern the VHD-FC reliability and performance in standard and failure modes as well as the technical-and-economic indexes and operation parameters of drive competitiveness, which are defined by specific designation of engineering hydraulically operating object.

In references, there is a lack of approaches to describe the justified technical requirements for the vision systems (VS) of industrial robotics complexes (IRC). Therefore, an objective of the work is to develop a technique that allows substantiating requirements for the main quality indicators of VS, functioning as a part of the IRC.The proposed technique uses a model representation of VS, which, as a part of the IRC information system, sorts the objects in the work area, as well as measures their linear and angular coordinates. To solve the problem of statement there is a proposal to define the target function of a designed IRC as a dependence of the IRC indicator efficiency on the VS quality indicators. The paper proposes to use, as an indicator of the IRC efficiency, the probability of a lack of fault products when manufacturing. Based on the functions the VS perform as a part of the IRC information system, the accepted indicators of VS quality are as follows: a probability of the proper recognition of objects in the working IRC area, and confidential probabilities of measuring linear and angular orientation coordinates of objects with the specified values of permissible error. Specific values of these errors depend on the orientation errors of working bodies of manipulators that are a part of the IRC. The paper presents mathematical expressions that determine the functional dependence of the probability of a lack of fault products when manufacturing on the VS quality indicators and the probability of failures of IRC technological equipment.The offered technique for substantiating engineering requirements for the VS of IRC has novelty. The results obtained in this work can be useful for professionals involved in IRC VS development, and, in particular, in development of VS algorithms and software.

The paper considers dynamics of formation and development of polygraph-using investigations (PUI) at the Department "Information Security" and Regional Training and Research Centre "Security" (RUNTS) in BMSTU. These studies are conducted to make diagnose that a person conceals information on the past events. The paper describes creating a unique lecture and laboratory module in PUI at the Department in 2008. It shows RUNTS activities in 2008-2015, giving assistance to public authorities to use the PUI and, in particular, providing assistance to Investigative Committee of the Russian Federation in the advanced training of specialists in PUI and developing a "Typical technique for forensic psychophysiological expertise using a polygraph" for them. The paper shows that the educational process carried out by the Department is reconciled with RUNTS works in the field concerned.

The work concerns the simulating peculiarities of heat transfer to the gas coolants with low values of the Prandtl number, in particular, to the binary mixtures of inert gases.The paper presents simulation results of heat transfer to the fully established flow of a helium-xenon mixture in the round tube of 6 mm in diameter with the boundary condition of the second kind. It considers a flow of three helium-xenon mixtures with different helium content and molecular Prandtl numbers within the range 0.239–0.322 and with Reynolds numbers ranged from 10000 to 50000. During numerical simulation a temperature factor changed from 1.034 to 1.061. CFD-code STAR-CCM+ that is designed for solving a wide range of problems of hydrodynamics, heat transfer and stress was used as the primary software.The applicability of the five models for the turbulent Prandtl number is examined. It is shown that the choice of the model has a significant influence on the heat transfer coefficient. The paper presents structural characteristics of the flow in the wall region. It estimates a thermal stabilization section to be approximately as long as 30 diameters of tube.Simulation results are compared with the known data on heat transfer to gas coolants with low values of the Prandtl number. It is shown that V2F low-Reynolds number -ε turbulence model with an approximation for the turbulent Prandtl number used according Kays-CrawfordWeigand gives the best compliance with the results predicted by relationships of Kays W.M. and Petukhov B.S. The approximating correlation summarizes a set of simulation results.Application of the work results is reasonable when conducting the numerical simulation of heat transfer to binary gas mixtures in channels of different forms. The presented approximating correlation allows rapid estimate of heat transfer coefficients to the gas coolants with a low value of the molecular Prandl number within the investigated range with a flow through the circular tube.

The paper considers a problem of falling the partially wetting liquid across solid surface taking into account the disjoining pressure for liquid particles in its thin layers close to the three phase contact line. Within the frame of dropping liquid hydrodynamics it is easy to take into consideration the surface tension. On the other hand, with available surface tension, the attempts to fulfill Yung condition for a contact angle encounter truly insurmountable difficulties. Generally speaking, this problem has no solution within the limits of standard hydrodynamic theory of viscous liquid if the surface tension occurs and, at the same time, it is necessary to fulfill Yung condition for partial wetting. These problems can be solved if, instead of Yung condition, which is specified on the three phase contact line, the task is reformulated taking into account an additional chemical potential (or, in other words, the disjoining pressure) of the liquid particles in thin liquid layers close to the three-phase contact line. This approach allows us to formulate the appropriate problem of mathematical physics in the consistent closed-form. The unique dependence of the disjoining pressure on the liquid film thickness and the decline angle of the free surface leads to degeneration of hydrodynamics equations on the three phase contact line, on the one hand, and to fulfilling the Yung condition, on the other one. The paper demonstrates application of the developed theory in the context of calculating liquid surface form at different movement velocities. The asymptotic relationships obtained from the results of numerical experiments allow us to describe the variation law of the apparent 'dynamic' contact angle versus rate of the falling liquid from the wetted surface in the way suitable for calculations.

The aim of the work is to study characteristics of magneto-static waves in the tangently magnetized films with crystallographic orientations of 100 and 110 types. Properties of the symmetry of planes allow us to set orientation of magnetization vector of only one angular variable because both this vector and a magnetizing field will be located in the film plane. This circumstance significantly simplifies calculations. Dispersion laws of magneto-static waves are derived, and temperature coefficients of frequencies are calculated on their basis. Angular dependences of obtained expressions are analyzed. The special attention is given to the orientations of the magnetization vector coinciding with directions of the tangential crystallographic axes of 100 , 110 , 111 types. These directions are characterized by extreme frequency values and their temperature coefficients. The paper studies conditions under which there is a zero value in the angular dependence of the frequency temperature coefficient. The investigation concerned the analysis of a sign of the temperature coefficient for 100 and 110 directions in a film with 100 orientation and for 100 and 111 directions in a film with 110 orientation. The sign inverse conditions lead to the inequalities making a connection between the film magnetic parameters themselves. The paper analyses conditions of thermo-stabilizing frequencies of a surface magneto-static wave spectrum in the yttrium iron garnet film. It is found that in 100 and 110 orientation films such conditions can be satisfied in the long-wave part of a spectrum. In this case a temperature coefficient is positive for the axis of 100 type and negative for the axes of 110 and 111 types. For comparison, the 111 orientation films possess weak anisotropy of the surface wave characteristics. In such films a temperature coefficient is negative for all tangent directions. The paper gives results of experimentally investigated yttrium iron garnet films with orientation of 100 type. It shows that frequencies of a surface wave in these films can be thermo-stabilized. The work results can be used to improve characteristics of film materials and increase thermal stability of spin wave devices.

The paper considers an issue of updating a turbine blade finite element model. The turbine blade is fixed in the special rig and the unknown contact conditions strongly influences on the blade dynamics. Hence, there is a difference between the real blade dynamic characteristics and the results of the finite element simulation. The task is to update the blade FE model on the basis of the modal test data to obtain fine dynamic model of the structure. The experimental modal parameters are known with some scatter, which is the result of measurement errors, and some differences from blade to blade within the kit of parts.The proposed algorithm is capable to update the turbine blade finite element model by variation of elasticity modulus in contact areas taking into account the experimental modal parameters scatter. It is worth noting that elasticity modulus of finite elements near the contact area should be considered as unknown contact stiffness parameters.The stochastic updating algorithm based on the sensitivity analysis is proposed. The paper presents equations to define sensitivity coefficients and provides the special recurrence relations, on which the proposed algorithm is based. The eigenvalue problem is resolved repeatedly with system parameters changing during the algorithm implementation. The system parameters (elasticity modulus in the contact areas) are recalculated according to the recurrence relations, mentioned above. To implement the proposed algorithm, a special software in C++ language has been developed.The proposed algorithm has demonstrated its efficiency for updating the finite element model of the complex structure. Thus, the differences between the calculated eigenfrequencies and those of identified from modal testing have been reduced from 13% to 3%. The updated model of the turbine blade could be used for accurate simulation of the blade dynamic behavior under different operating conditions.

Probability-statistical framework of reliability theory uses models based on the chance failures analysis. These models are not functional and do not reflect relation of reliability characteristics to the object performance. At the same time, a significant part of the technical systems failures are gradual failures caused by degradation of the internal parameters of the system under the influence of various external factors.The paper shows how to provide the required level of reliability at the design stage using a functional model of a technical object. Paper describes the method for solving this problem under incomplete initial information, when there is no information about the patterns of technological deviations and degradation parameters, and the considered system model is a \black box" one.To this end, we formulate the problem of optimal parametric synthesis. It lies in the choice of the nominal values of the system parameters to satisfy the requirements for its operation and take into account the unavoidable deviations of the parameters from their design values during operation. As an optimization criterion in this case we propose to use a deterministic geometric criterion \reliability reserve", which is the minimum distance measured along the coordinate directions from the nominal parameter value to the acceptability region boundary rather than statistical values.The paper presents the results of the application of heuristic swarm intelligence methods to solve the formulated optimization problem. Efficiency of particle swarm algorithms and swarm of bees one compared with undirected random search algorithm in solving a number of test optimal parametric synthesis problems in three areas: reliability, convergence rate and operating time. The study suggests that the use of a swarm of bees method for solving the problem of the technical systems gradual failure reliability ensuring is preferred because of the greater flexibility of the method and the simplicity of the algorithm parameter settings.