Development of algorithms for feature matching in the method for reconstucting high-precision digital surface models

The method for reconstructing high-precision digital surface models baseed on stereo matching of point and contour features is presented. Methods for extracting points and contours in images, and their subsequent matching are considered. Additionally the specific items of the proposed method are underlined from the point of view of using these image features for solving the final problem of detection features of the surface relief. Special attention is paid to the transition from local stereo matching to the global one. The necessity of this transition for successful solving the problem of a qualitative relief model with a minimal number of outliers is shown. The advantages of the developed method are demonstrated by the example of reconstructing a surface relief based on two stereo pairs of aerial images of different resolutions.     

Time to cool a cryogenic object by a gaseous cryogenic agent

Dependences to compute the cooling time of a single-channel object are obtained theoretically and confirmed experimentally.Notation D mass of helium in the channel - M mass of metal of the channel wall - G mass flow rate of the cryogenic agent - G_equ equivalent mass flow rate - c_p, c_m mean integrated specific heat of the cryogenic agent and the channel wall material - U perimeter - cooling time - ₁ time of the first cooling period - T₂ time of the second cooling period - channel wall temperature - T flow temperature - T_o initial flow temperature - T_in flow temperature at the channel input - W flow velocity - L channel length - L_in, L_out lengths of the delivery and removal pipelines - F, F_in, F_out cross-sectional areas of the channel being cooled, and of the delivery and removal pipelines - F_s total heat-transfer surface - d channel inner diameter - d_in, d_out inner delivery and removal pipeline diameters - P flow pressure - P flow pressure at the input to the element - P_out flow pressure at the output from the element - G_o, G₁ initial and final flow rates of the cryogenic agent - z a coordinate - ¯z=z/L a dimensionless coordinate - dimensionless channel length - dimensionless cooling time - V₁ dimensionless temperature - k_G,a, k _u , f, m, , g parameters - A, B constants - Re Reynolds number - R gas constant - coefficient of dynamic viscosity - hydraulic drag coefficient - coefficient of heat elimination Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 4, pp. 629–635, October, 1980.     

“Hollow spheres” model of powder densification

Conclusions The application of dynamic pressure to a powder leads, depending on the values of the pressing parameters Re and and of the strengthening parameters m and n, to its densification either to some end porosity or to the nonporous state. With decreasing the end density of a powder attainable during pressing grows. At a constant value of of 0.3, 0.4, or 0.5 the dependence of the end density on the Re number is slight. The strengthening of material increases the end porosity of pressed parts.Translated from Poroshkovaya Metallurgiya, No. 2(206), pp. 24–26, February, 1980.     

Calculating the hydraulic characteristics of two-phase-helium circulation systems

An approximate analytical solution is obtained for calculating the pressure drop in the flows of a boiling two-phase liquid in a heated channel. The dependence of the maximum temperature in the channel on the rate of flow of the cryogenic fluid is determined.Notation c_p isobaric heat capacity - d diameter - F lateral surface of channel - f surface of channel cross section - G mass velocity of liquid - q external heat flux to a unit of the channel length - i enthalpy (i -enthalpy of the liquid on the saturation line) - L channel length - l length of boiling section - P pressure - P pressure drop - P_f pressure drop in the boiling section - r heat of vaporization - T temperature - T_h effective temperature - v specific volume of liquid - v specific volume of saturated vapor - x mass content of vapor - z coordinate - friction coefficient - coefficient of local fluid resistance in the single-phase section Indices 0, 2 parameters corresponding to the outlet and inlet cross sections of the channel - 1 parameters corresponding to the beginning of boiling of the liquid - s equilibrium parameters Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 41, No. 3, pp. 396–401, September, 1981.     

Environmental Assessment of Products over the Complete Life Cycle

Russian Engineering Research - The environmental impact of products is assessed over the complete life cycle. The proposed approach to impact assessment takes account of all the potential hazards...     

Technology for the Visual Inspection of Aircraft Surfaces Using Programmable Unmanned Aerial Vehicles

Journal of Computer and Systems Sciences International - The technology for the visual inspection of aircraft surfaces using programmable unmanned aerial vehicles (drones) is presented. When...     

Installations for producing electrospark erosion- and abrasion-resistant coatings on the blades of steam turbines of thermal and nuclear power plants

This article is devoted to the creation of installations for generating electric spark erosion- and abrasion-resistant protective and strengthening coatings on the blades of steam turbines of thermal and nuclear power plants such as GBF and KGB, developed and manufactured by the OAO VTI. A characteristic feature of the installations is the fact that they are equipped with electromechanical exciters with a high service life and reliability compared to electromagnetic ones. The study data for the electrical characteristics of the KGB-5 installation are presented.