V. A. Ivanov, V. S. Kirichuk, and V. P. Kosykh
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia, E-mail: kirichuk@iae.nsk.su
Pages: 205-207
The accuracy of estimating the shift between two discrete images of the same scene is analyzed in the situation when the shift value is under the sampling step. A new algorithm is proposed for estimating the shift. The algorithm requires a low computational complexity and its estimate errors are small. Results of computational experiments verify its advantages over the known algorithms.
Yu. N. Zolotukhin, K. Yu. Kotov, and A. A. Nesterov
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: zol@idisys.iae.nsk.su
Pages: 218-225
A control scheme for mobile robot formation in the leader following mode is proposed. It enables to track the target and is based on using a sliding mode along the desired trajectory in the state space. Results of modeling using MATLAB/SIMULINK environment are presented. They confirm efficiency of the proposed algorithm.
S. I. Vyatkin
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: sivser@mail.ru
Pages: 226-231
Freeforms synthesized by means of perturbation functions are considered. A special feature of the freeforms based on the scalar perturbation functions and the method of their visualization is that the time of geometrical processing and the amount of data required for modeling the surface do not depend on its geometry. The freeforms based on the analytical perturbation functions have an advantage of spline representation of surfaces, that is, a high degree of smoothness, and an advantage of arbitrary form for a small number of perturbation functions.
A. M. Kovalev1, V. E. Lishchenko2, and M. V. Stepanov2 1Technological Design Institute of Scientific Instrument Engineering, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: vlish@ngs.ru
Pages: 232-238
Concepts of using new perspective systems in computer graphics are considered. The systems open up opportunities for rendering 3D visual scenes similar to the natural visual perception.
A. V. Likhachev
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia, E-mail: ipm1@iae.nsk.su
Pages: 239-245
The filtering of projections in tomography algorithms, which is based on the regularization of distribution 1/z2, is investigated. Numerical simulations validate that changing the filter support will substantially improve the tomograms. Comparison of the results of reconstruction by the 1/z2-filtering algorithm and the Shepp
V. A. Ivanov
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia, E-mail: vaivanov@iae.nsk.su
Pages: 246-251
Types of interpolation in calculating the frame-to-frame difference for decreasing the influence of the stationary background when detecting point objects are compared. The comparison is done for an observation system with a photodetector array and an oscillating axis. Methods of interpolation in the presence of a fractional shift (below the photodetector array step) are considered. Computational experiments estimating the efficiency of the methods upon detecting point objects were carried out.
V. P. Koronkevich, A. I. Lokhmatov, A. E. Matochkin, and A. R. Gerent
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia, E-mail: matochkin@iae.nsk.su
Pages: 252-255
The possibility of decreasing the depth of interference region in the Fizeau interferometer configuration with a semiconductor laser is considered for problems concerned with inspection of plane-parallel plates.
I. G. Palchikova1, V. I. Kovalevskii1, and V. V. Shelkovnikov2 1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: pal@iae.nsk.su 2Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: vsh@nioch.nsc.ru
Pages: 256-261
An experimental assembly is created and a method for simultaneous studying dynamics of phototransformation of holographic photopolymer materials by spectrophotometric and interferometric methods is elaborated. A special diffraction interferometer with combined branches is developed. The interferometer ensures the sensitivity to the change in the refractive index Dn ~ 10-3 for ~100 mm specimens.
G. A. Lenkova
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: lenkova@iae.nsk.su
Pages: 262-273
Peculiarities of designing and determining the refraction (lens power) and the diffraction efficiency of bifocal hybrid (diffractive-refractive) intraocular lenses (IOL)
A. K. Komarov
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: komarov@iae.nsk.su
Pages: 274-277
Passive mode-locking with equidistant ultrashort pulses in the laser cavity due to additional weak modulation of the losses or the refractive index is analyzed. The velocity of the relative pulse motion and the time of establishing the harmonic passive mode-locking mode are analytically estimated.
a:2:{s:4:"TEXT";s:66:"A. P. Kolchenko, V. S. Terentyev, and Yu. V. Troitskii†";s:4:"TYPE";s:4:"html";}
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: kolchenko@iae.nsk.su
Pages: 278-283
A multibeam interferometer with oscillating mirrors is theoretically investigated. The exact solution to the main equation for the interferometer and expressions for its transfer functions, i.e., generalized reflection and transmission factors, are obtained in a plane-wave approximation.
Yu. A. Lemeshko, Yu. V. Chugui, and A. K. Yarovaya
Technological Design Institute of Scientific Instrument Engineering, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia, E-mail: chugui@tdisie.nsc.ru
Pages: 284-291
A method for measuring diameters of circular reflecting cylinders is discussed. The method consists in processing a diffraction pattern that is formed in the near-field zone by illuminating the object edges by a plane monochromatic beam. An equivalent mathematical model of forming a diffraction field is developed and experimentally validated. The model makes it possible to obtain analytical functions describing the distribution of the field from the circular reflecting cylinder. The influence of the cylinder reflecting surface on the diffraction pattern parameters is studied. A highly accurate algorithm is proposed for calculating the diameter of the cylindrical article by its Fresnel diffraction pattern with an error under 1 m.
P. E. Tverdokhleb and Yu. A. Shchepetkin
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, E-mail: peter@iae.nsk.su
Pages: 292-298
a:2:{s:4:"TEXT";s:11:"V. P. Il’in";s:4:"TYPE";s:4:"text";}
Institute of Computational Mathematics and Mathematical Geophysics, SB RAS Novosibirsk, Russia, E-mail:ilin@sscc.ru
Pages: 99-111
Topical issues of parallelizing computational methods and technologies for implementing the main mathematical modeling stages in solving a wide range of large applied problems are considered. Computation
M. I. Ivanov1, V. A. Kateshov1, I. A. Kreme1r, and M. V. Urev2 1Centre RITM Corporation, Novosibirsk, Russia, E-mail: Kremer@aoritm.co 2Institute of Computational Mathematics and Mathematical Geophysics, SB RAS Novosibirsk, Russia, E-mail: urev@nmsf.sscc.ru
Pages: 112-120
Some issues of modeling stationary electromagnetic fields for 3D regions including inhomogeneous conducting media are considered. The problems are formulated in terms of potentials. It is proposed to solve the problems by a subdomain iteration method. A model example illustrates the convergence of the proposed method
M. I. Ivanov1, V. A. Kateshov1, I. A. Kremer1, and M. V. Urev2 1Centre RITM Corporation, Novosibirsk, Russia, E-mail: Kremer@aoritm.com 2Institute of Computational Mathematics and Mathematical Geophysics, SB RAS Novosibirsk, Russia, E-mail: urev@nmsf.sscc.ru
Pages: 121-130
Some issues of calculating the unstationary electromagnetic fields in 3D media with a piecewise homogeneous conductivity are considered. Potential statements of the problems in the time domain are used. An approach to solving this kind of problems is proposed. The computational stability of the method at late times is verified on a model example.
M. G. Persova1, Yu. G. Soloveichik1, G. M. Trigubovich2, M. V. Abramov1, and A. V. Zinchenko1 1Novosibirsk State Technical University Novosibirsk, Russia, E-mail: solov@fpm.ami.nstu.ru 2Siberian Research Institute of Geology, Geophysics, and Mineral Resources, Novosibirsk, Russia, E-mail: tgm@sniiggims.ru
Pages: 131-138
Based on three-dimensional mathematical modeling of nonstationary electromagnetic fields with a source in the form of an ungrounded current loop, two technologies are compared: areal electromagnetic sounding with a fixed source and remote sensors and profile survey with a coaxial device (the latter has already found numerous applications). Advantages of sounding with the use of remote sensors for electromagnetic field recording are demonstrated by examples of solving two problems.
M. G. Persova, Yu. G. Soloveichik, E. V. Khitsenko, M. G. Tokareva, and Yu. V. Trakimus
Novosibirsk State Technical University Novosibirsk, Russia, E-mail: solov@fpm.ami.nstu.ru
Pages: 139-146
Possibilities are studied of finding deep features, based on the measurements of an unsteady electric field in a cased well located far from another cased well with a vertical electric line exciting the field. The study is performed by means of finite-element modeling developed by the authors. The results obtained confirm the presence of information on the exploratory prospect in the recorded signals. Methods of extraction of this information from experimental data are discussed.
a:2:{s:4:"TEXT";s:51:"V. P. Il’in1 and S. G. Pudov2";s:4:"TYPE";s:4:"html";} 1Institute of Computational Mathematics and Mathematical Geophysics, SB RAS Novosibirsk, Russia, E-mail: ilin@sscc.ru 2Technological Design Institute of Digital Technique, SB RASNovosibirsk, Russia, E-mail: pudov@dote.ru
Pages: 147-152
Iterative solving SLAE with nonsymmetric square real matrices by means of the robust modified method of generalized conjugate residuals and the hierarchical family of algorithms for incomplete matrix decomposition into triangular multipliers is considered. Special features of software algorithms based on symbolic factorization of matrices stored in a sparse row format are described. Experimental numerical results are given for a representative series of model problems. They demonstrate comparative efficiency of the methods.
A preconditioned semi-conjugate residual algorithm for solving systems of algebraic equations with a nonsymmetric square matrix is presented. Most of the calculations in the algorithm is accounted for vector operations whose number grows quadratically with the number of stored directing vectors. A parallel implementation of the algorithm is studied experimentally, the Eisenstat modification being chosen as the preconditioning. An algorithm for parallelizing matrix operations is presented for special problems.
A. M. Matsekh1 and E. P. Shurina2 1Los Alamos National Laboratory, Los Alamos, USA E-mail: matsekh@lanl.gov 2Novosibirsk State Technical University, Novosibirsk, Russia 2Institute of Computational Technologies, SB RAS Novosibirsk, Russia, E-mail: shurina@online.sinor.ru
Pages: 159-169
A new implementation of the Godunov-inverse iteration, that is, inverse iteration with guaranteed accuracy, is presented. A new implementation of the Cullum
E. P. Shurina1, O. V. Nechaeva2, and O. V. Nechaev2 1The Novosibirsk State Technical University, Novosibirsk, Russia, E-mail: shurina@online.sinor.ru 2Looch Research and Production Association for Geophysical Equipment, Novosibirsk, Russia, E-mail: howl@ngs.ru
Pages: 170-176
A mixed variational problem formulation is proposed to find the electric field as a solution to a second-order differential equation and the magnetic flux density vector as a solution to a first-order differential equation.
Y. L. Gurieva
Institute of Computational Mathematics and Mathematical Geophysics, SB RASNovosibirsk, Russia, E-mail: yana@lapasrv.sscc.ru
Pages: 177-181
S.A. Isaev1, P.A. Baranov2, A.G. Sudakov1, and V.B. Kharchenko1 1Saint-Petersburg State University of Civil Aviation, St. Petersburg, Russia
Pages: 169–186
On the basis of the solution by multi-block computational technologies of Reynolds equations closed with the aid of the equations of the model of Menter
Results of T-203 wind-tunnel tests of an elastic airplane model dynamically similar to Tu-204 aircraft equipped with a passive wing load reduction system are reported. The wing load reduction system comprised two auxiliary aerodynamic surfaces of the slotted-interceptor type installed symmetrically on the upper surface of the lifting wing at the boundary-layer height. It was found that, with the operating system, the additional bending moments induced by symmetric vertical discrete gusts in the wing root and at the fuselage mid-body decreased by 20 %, with simultaneous increase observed in the flexure-pylon flutter speed.
a:2:{s:4:"TEXT";s:83:"A.V. Sobolev1, V.I. Zapryagaev1, and V.M. Mal’kov2";s:4:"TYPE";s:4:"html";} 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Pages: 193–200
Properties of gas-jet ejectors with converging mixing chamber operated under critical and subcritical flow conditions are examined. Establishment of the critical operation mode in such ejectors started up with and without the secondary gas flow is considered. The mechanism underlying the emergence of flow pulsations at low rates of the low-head flow is described. Results of an experimental study aimed at the improvement of ejector discharge characteristics by chamber-length reduction and related mixing enhancement are reported. As flow-mixing elements, slotted heads, chevrons, and tubs are considered. The best discharge characteristics were obtained with nozzles provided with tubs.
Theoretical and simulation study was carried out for eliciting conditions when an intentionally formed system of oblique shocks can be used for control of parameters of condensed phase in supersonic flow. The key features of flow were analysed for two versions of duct, which are different in geometry of nozzle and acceleration headpiece. The results confirmed the feasibility of intentional impact on the structure of developing set of shock waves through changes in the duct profile: this would change the particle trajectories.
A new method for measurement of viscoelastic properties of materials, based on the exact solution of the problem of the forced oscillations of a flat sample loaded by inertial mass, is proposed. The device for these measurements is described. The elasticity modulus and loss tangent are measured within the frequency range from 100 Hz to 10 kHz at relative deformation of a sample below 1 %. The approximate formulas for calculation of viscoelastic properties are derived, and the conditions of their applicability are determined. The methods for expansion of the frequency range and measurement of materials with extremely high loss tangent are proposed. The proposed method is compared with the current Standard. It is shown that the new method has the higher accuracy and expanded range of parameter measurements, and the construction of device is easy and reliable, since it does not require the knowledge on the oscillation properties of vibration source.
The flow of a viscous liquid layer in an open inclined channel under the turbulent mode is considered in this paper. To describe turbulent viscosity, the Van Driest model is used. The spectrum of characteristic values of the problem on linear stability of a plane-parallel flow is studied numerically. Parameters of the maximal growth waves are found out, the surface tension effect is studied, and theoretical results are compared with experimental data.
In thin films of liquid falling over an inclined surface random (or non-random) small dry spots shut and disappear or expand into the large-scale dry spots depending on the initial spot sizes and parameters of the liquid film. On consideration of the gravity forces, inertial forces of the film and surface tension, affecting the elements of a roller surrounding the dry spot, we have formulated a criterion, which helped us to answer the following question: if this spot shuts or not? This criterion includes the numbers of Bond and Reynolds and the contact wetting angle as the determining parameters. It is generalization of the known Hartley
The fluorescence method was used to measure the instantaneous thickness field of the falling non-isothermal water film. The process of rivulet formation in a heated film was registered. Measurement averaging allowed determination of the degree of transverse deformation of a film. In the lower half of the heater within the interrivulet zone of the non-isothermal film, the wave amplitude decreases with a rise of the heat flux and reduction of the average thickness. Two zones of the heat flux effect on liquid film deformation were distinguished. At low heat fluxes, the film flow is weakly deformed. At high heat fluxes the thermal-capillary forces provide formation of rivulets and a thin film between them.
Calculation data for characteristics of concave holographic arrays are reported, allowing development of low-size spectrometers with medium and high spectral resolution. The holographic arrays were fabricated around new subnanostructured films of chalcogenide semiconductors. A medium-resolution, small-size spectrometer was used to measure the distribution of temperature in the gas flow emanating from a DC plasmatorch with sectioned inter-electrode insert by the relative-intensity method. Presently available methods for measuring the temperature of non-uniform optically thin plasma were employed. A comparison of spectral and thermophysical methods for temperature measurements is given.
Estimation criteria for contribution of the main energy sources and sinks to complex heat transfer of the rod thermal cathodes were obtained for the quasi-one-dimensional statement of the heat problem. Criterial relationships allow determination for operation temperatures of the high-current long cathodes. A method for optimization of the electrode thermal state was developed. Calculations by the criterial method correlate with the experimental results.
Peculiarities of the formation of melt hydrodynamics in the molten pool of electric arc as a result of a viscous interaction with the arc plasma flow and the effect of electromagnetic forces are considered. It is shown that in a relatively shallow pool, the role of viscous interaction with plasma flow predominates electromagnetic forces. In a deeper pool, the flow in peripheral upper region is formed as before by a viscous interaction between plasma and melt, and the electromagnetic forces dominate in deep regions.
An extremal problem is formulated for computing the distributions of pressures, flow rates, and temperatures in the steady operation regime of thermal network of arbitrary configuration from data of measuring these parameters at individual network points. For its solution, it is proposed to use a non-conventional mathematical model of a non-isothermal flow distribution whose peculiarity is the invariance to flow directions, which are not known in advance. The approach and the computational scheme for estimating the parameters of the thermal/hydraulic regime are proposed and tested with a numerical example.
For the purpose of the development and introduction of the arrangements aimed at increasing the slagless power, economy, and reliability of the P-67 boiler of the 800 MW unit of the Berezovskaya Power Plant No.1, the variation of heat-engineering characteristics of the coal (lignite) of the open-cast mine
The scheme and cycle of a promising highly economic coal-dust combined steam-cycle power unit are presented. The flow-rate, thermodynamic, and design figures of high-temperature sets (a coal-dust boiler and a high-temperature steam turbine) are considered.
May 24, 2007 was the 80th anniversary of the famous scientist in the field of thermophysics Professor, academician of RAS Alexander I. Leontyev. His colleagues, disciples, and friends congratulate Alexander I. Leontyev on his glorious jubilee and wish him good health and happiness.
May 6, 2007 was the 70th anniversary of the well-known thermophysicist, Doctor of Technical Sciences, Professor, corresponding member of RAS Eduard P. Volchkov. His colleagues, disciples, and friends con-gratulate Eduard P. Volchkov on his glorious jubilee and wish him good health, happiness and successes in his scientific activities.
Professor Nikolay A. Rubtsov, a well-known scientist in thermal physics, winner of the State Award, celebrated his 80th anniversary on April 1, 2007. N.A. Rubtsov
