Summary
Extreme problems for nonlinear Differential-operational systems and inclusions
Modebadze T.A. and Sokhadze G.A.
Akaki Tsereteli State University, Kutaisi
The problem of minimization of the functional by the solutions of differential-operational inclusions is discussed. The conditions of handling the problem stated are described.
Keywords: extreme problem, nonlinear system, inclusion, optimization.
Summary
On the application of fuzzy linguistic variables at choosing the optimal projects
Bidjuk P.I., Kordzadze T.Z. and Sokhadze G.A.
Akaki Tsereteli State University, Kutaisi
Kiev Technical University, Kiev, Ukraina
The computing capability of so-called fuzzy mathematics at choosing the optimal solutions is demonstrated with a particular numerical example.
Keywords: fuzzy variable, optimal choice, mathematical model.
TWO-DIMENSIONAL BOUNDARY PROBLEMS OF THERMODIFFUSION WITH MIXED BOUNDARY CONDITIONS
Bezhuashvili Y.A. and Buadze T.G.
Georgian Technical University
Abstract. Plane boundary problems of the conjugate theory of theo-rmodiffusion for multiply connected domains are discussed. The theorems on the existence and uniqueness of solutions in the class of regular functions are proved for the considered problems by using the method of potential and singular integral equations.
Keywords: thermodiffusion two-dimensional boundary problems, mixed boundaryconditions.
APPROXIMATE SOLUTIONS OF PLANE MIXED BOUNDARY PROBLEMS OF THE CONJUGATE THEORY OF THERMODIFFUSION
Bezhuashvili Y.A. and Buadze T.G.
Georgian Technical University
Abstract. Using the method of generalized Fourier series, approximate solutions for plane mixed boundary problems of the conjugate theory of thermodiffusion were constructed.
Keywords: thermodiffusion, conjugate theory, plane boundary problems, generalized Fourier series.
Summary
Mathematician Soso Kalandarishvili
Sokhadze G.A.
Akaki Tsereteli State University, Kutaisi
There is presented a brief survey of works performed by well-known mathematician Soso Kalandarishvili in the field of the theory of random processes and their applications in engineering and medicine.
Keywords: mathematics, survey, theory of random processes, Soso Kalandarishvili.
Summary
On the possibility of becoming a”Light-eater” for a man
Khvedelidze M.A.
International Informatization Academy
Georgian Informatization Academy
Some reports about the possibility of becoming a “light-eater” for a man, including the ones about a yogi from India who has been able to live without food and water for years, yet keeping fit, are analyzed. A lot of facts which could not be explained by modern science are cited. At the same time, it is well known that an autotrophic plant, chlorella, can transform into a heterotrophic form, which could be observed in darkness if the nutrient medium is replaced by organic substances providing the life of animals and men. This fact is testimony to the adaptation of live systems to the environment. The evolution of self-organization of matter led to the creation of mankind which could organize it at a higher level. Hence it is not improbable that the energy of light could be used more efficiently by men.
Keywords: man, phenomenal events, possible explanation.
Low-Field Response of the Third Harmonic of Josephson Junctions in High-Temperature Polycrystalline Superconductors
Metskhvarishvili I.R., Gamkrelidze K.P., Tsiskarishvili N.Sh. and Nadoeva I.A.
Iv. Javakhishvili Tbilisi State University
Abstract. The third harmonic response of high-temperature polycrystalline superconductor Tl2Ba2Ca2Cu3O10 was measured in the presence of a low ac excitation field and a dc magnetic field superimposed on it. The Kim-Anderson critical state models are used to explain the nonlinear magnetic response in the Josephson Junctions.
Keywords: polycrystalline superconductor, third harmonic, Josephson junctions, critical state model.
Microstructure and Thermoelectrical Properties of Complex-doped Si0,85Ge0,15 Alloys
- Bokuchava G.V., Barbakadze K. G., Gabrichidze L. L. and Darsavelidze G. Sh.
- Ilia Vekua Sukhumi Institute of Physics and Technology
- Ferdinand Tavadze Institute of Metallurgy and Materials Science
Abstract: Microstructure, microhardness, phase composition and thermoelectrical properties of complex-doped polycrystalline Si-Ge alloys obtained by Czochralski method were studied. The determining role of the real structure state, the interactions and the thermal stability of defects for the structural-sensitive characteristics of Si-Ge alloys was analyzed.
Keywords: microstructure, microhardness, thermal conductivity, silicon-germanium alloy, gallium phosphide, boron, swirl-defect.
Dispersion strengthening of Austenitic Manganese Alloy by using the Aluminum Oxide NanoPowder and Vanadium
Oakley A.L., Ratishvili M.A., Margiev B.G., Chipashvili D.D., Bakuradze A.I., Ebanoidze D.D.,
Gachechiladze A.A. and Gabunia V.M.
Ferdinand Tavadze Institute of Metallurgy and Materials Science
Abstract. New technology of dispersion strengthening of austenitic manganese alloy (so-called Hadfield Steel) by using aluminium oxide nanopowder and vanadium has been developed. The developed technology is unique, as the dispersion, strengthening of the alloy was made by direct introduction of the Al2O3 nanopowder into the loquid metal. The sizes of nanoparticles were in the range of 30-90 nm. At the same time, the liquid metal was modified with vanadium. The developed technology provides the increase in the strength and the plastic, and impact properties of the alloy up to 40%, while the increase in the strength does not reduce the plasticity of the alloy. The wear resistance increases by 25%.
Keywords: austenite, manganese alloy, aluminum nanooxide, vanadium, dispersion strengthening.
Rigorous calculation of the waveguide tee with cylindrical inhomogeneity in the resonant part
Garuchava G.T., Kekelia G.V., Khosroshvili N.O. and Sichinava O.V.
Georgian Technical University
Abstract: The rigorous calculation of the waveguide tee with cylindrical inhomogeneity in the resonant part is discussed. After realization of all boundary conditions, we obtain the first-kind infinite system of linear algebraic equations, which could be reduced to the second-kind infinite system of linear algebraic equations by the regularization method. The derived system is solvable by the method of reduction.
Keywords: waveguide tee, cylindrical inhomogeneity, resonator part, method of moments, method of reduction.
WAVE STRUCTURE FUNCTIONS OF ELECROMAGNETIC WAVES MULTIPLY SCATTERED BY the ANISOTROPIC LAYER OF COLLISIONAL MAGNETIZED TURBULENT PLASMA
Jandieri G.V., Gomidze N.Kh., Diasamidze M.R., Jabnidze I.N., Davitadze M.I. and Takidze I.G.
Georgian Technical University
Abstract. The wave structure functions of phase and logarithmic relative amplitudes were computed for two plane electromagnetic waves of different frequencies scattered by the turbulent anisotropic magnetized plasma layer of finite thickness in approximation of complex geometrical optics using the perturbation method. Numerical calculations were carried out for F-region of the ionosphere using the satellite data on ionospheric plasma parameters.
Keywords: turbulent magnetized plasma, anisotropic layer, geometrical optics approximation, correlation function of the phase, structural function.
Kinetics of defect formation in the n-Si crystals
irradiated with protons
Pagava T.A., Maisuradze N.I., Khasia N.I., Kharshiladze N.Sh. and Chubinidze Ts.A.
Georgian Technical University
Abstract. The aim of this study is to gain insight into the effect of the charge state of nonequilibrium vacancies on the processes proceeding in silicon crystals during irradiation and annealing. The n-Si floating-zone crystals with the electron concentration of N =6x1013 cm–3 were irradiated with 25 MeV protons at 300K. The irradiated crystals were studied by the Hall method at temperatures ranging from 77 to 300 K. It is shown that the nature and the energy spectrum of radiation defects in n-Si crystals are mainly controlled by the charge state of nonequilibrium vacancies.
Keywords: silicon, irradiation, defects.
Summary
Analysis of tracking systems with consideration of nonlinearity of the two-phase actuating motor
Bodokia T.D., Chkadua N.V. and Goniashvili E.S.
Georgian Technical University
As the output stage of tracking systems, two-phase induction servomotors with hollow rotors have gained widespread use. The nonmagnetic hollow rotor is equivalent use. The nonmagnetic hollow rotor is equivalent to one turn and hence it has low inductive resistance. On the stator of the motor, which is assembled from electrical steel sheets, control and excitation windings, the magnetic axes of which are shifted by 900, are arranged. In this work, the processes proceeding in the case when alternating voltage of constant amplitude is fed to the excitation winding, while a.c. voltage of alternating amplitude – to the control winding, are discussed.
Keywords: tracking system, two-phase motor, induction servomotor, hollow rotor.
Summary
Specific features of tracking systems on mobile bases
Chkadua N.V., Bodokia T.D. and Goniashvili E.S.
Georgian Technical University
At operation of the tracking system on a mobile base, there appear additional angles of rotation of the base. By these angles are meant the motion of the base and the input disturbing or controlling effects. It is demonstrated that the use of damping devices reduces the effect of the base rotation speed on the system dynamics.
Keywords: tracking system, mobile base, angle of rotation.
SUMMARY
THE SYSTEM OF AN INDUCTIVE CONCLUSION FOR MODELING OF INTELLECTUAL PROCEDURES
Lezhava G.G., Kamkamidze I.Sh. and Berikishvili Z.I.
Institute of Cybernetics
In this article the description of the system of inductive conclusion (CIC) the work of which is based on the such concepts as memory and learning, an inductive conclusion and formation of concepts is given. The representation about CIC allows us to consider the elementary information processes forming the base for "intellectual" functions of a higher level from the standpoint of evolutionary cybernetics.
Keywords: inductive conclusion, hybrid system, base of knowledge, abstraction.
Summary
Investigation of the properties of two-varIable simplex-grating designs with consideration of errors of measuring devices
Zedginidze I.G., Beraia N.O. and Darbaiseli M.S.
Georgian Technical University
The properties of D-, A- and E-optimality of simplex-grating designs of the first, the second and the third orders for two-variable systems at using the measuring devices having certain errors for determination of variable levels were studied. The errors of measuring devices were simulated by superimposing the random numbers distributed by the normal law on the coordinates of first-, second- and third –order designs. It was established that the properties of D-. A- and E-optimality of the abovementioned designs became worse to a certain extent if the measuring devices with inherent errors were used.
Keywords: experimental design, simplex design, measuring devices.
Summary
Investigation of some properties of first- and second-order designs for two variables under the conditions of experimental errors
Beraia N. O., Zedginidze I.G. and Bairamova A.T.
Georgian Technical University
The effect of errors of measuring devices on the properties of linear and second-order symmetric designs for two variables such as D-, A- and E-optimality was studied. For the second-order designs, the results were obtained at the value of the “star” arm equal to a=0.5; 1; 1.5. The simulation of the effect of errors of measuring devices on the properties of the designs under study was performed by superimposing the random numbers distributed by the normal law on the design coordinates.
Keywords: experimental design, first-order design, second-order design, experimental errors, measuring devices.
SUMMARY
THE EFFECT OF THE VELOCITY VECTOR PROFILE OF RUNNING-ON FLOW
ON THE FLOW-ABOUT REGIME
Davitashvili I.A.
Georgian Technical University
The results of solution of the problem of liquid flow about the airfoil are presented. Two versions of airfoil, the experimental one and the one obtained by optimization of the experimental airfoil, were considered. For both versions, two cases were studied: 1) The flow of viscous liquid had a rectilinear shape of velocity vector; 2) The flow of viscous liquid had a parabolic shape of velocity vector.
Keywords: airfoil, liquid flow, velocity vector, flow-about regime.
SUMMARY
A MODEL OF THE EFFECT OF DISPERSE INTERACTION ON THE TEMPERATURE
DEPENDENCE OF ELECTRON MOBILITY
Janelidze O.M.
Batumi State University
It is demonstrated that the analysis of experimental data on the temperature dependence of electron mobility in InP and GaAs should be performed with consideration for electron scattering by the dipole moment of quantum transitions of excited deep centers. The excitation of centers takes place as a result of localization of the energy of longitudinal acoustic vibrations of basic lattice atoms induced by foreign atoms as a bandpass filter of vibrations of the edge of Brillouin zone. The interaction potential is inversely proportional to the separation between the scattered electron and the electric moment of quantum transitions of hybrid electrons to power 3/2 and to the change in the electron energy at quantum transition.
Keywords: electron mobility, InP, GaAs, temperature dependence, disperse interaction.
SUMMARY
The reverse branch of Volt-Ampere Characteristic at low-temperature electric breakdown of GaAs
Janelidze O.M.
Batumi State University
The electrical properties of GaAs were investigated in the regime of impact ionization at 77K. It was revealed that, in the strong electric field, the conductivity was determined by a wide range of deep levels of different density, the section of recombination of hot electrons was much less than that of ionization, and the material was likely to contained the atoms with the increased number of blank electrons.
Keywords: deep centers, energy localization, dipole moment, mobility, impact ionization.
summary
on the stability of hydrodynamic tangential discontinuity in liquids with consideration for their surface tension force
Kirtskhalia v.g. and toloraia n.d.
sukhumi Institute of Physics and Technology
There is considered the problem of stability of the plane interface of two homogeneous incompressible liquids moving with velocity vo (hydrodynamic tangential discontinuity) in relation to perturbations of the interface. It is demonstrated that the surface tension force stabilizes the tangential discontinuity.
Keywords: liquid, liquid-liquid interface, hydro dynamic tangential discontinuity, surface tension, stability.
SUMMARY
Funcitons and architecture of network management systems
Lobzhanidze L.T. and Tevdoradze M.T.
Georgian Technical University
Basic functional groups of network management tasks are dicussed. There are also considered and characterized the network resources which could be acknowledged as main ones for efficient network management from the standpoint of QoS policy. The interrelation between the resources of the network such as the delay and the pass band is shown.
Keywords: network, architecture, resources, management, pass band, delay, QoS policy.
Summary
Assessment of the circuit diagram of efficient use of high-potential heat energy
Kevkhishvili N.A. and Natsvlishvili T.Sh.
Georgian Technical University
The circuit diagram of efficient use of high-potential heat energy and the procedure of its assessment are discussed. Ready-made devices are considered as parts of the step-down transformer; for example, as a load-bearing element, a thermal engine produced by TEDOM Company is used, the shaft of this engine being directly connected to a steam-compression refrigerating machine. The calculation results show that, in this case, the heat-transformation coefficient makes up 1.9-2.35. This means that the consumption of fuel will be cut in half as compared to a common heatimg plant.
Keywords: heat energy, circuit diagram, efficiency.
Summary
The basics of transmission in telecommunication systems based on NGN
Murjikneli G.G., Vekua T.A., Chitiashvili L.N. and Odilavadze Sh.Z.
Georgian Technical University
The topical issues of implementation of NGN technology into telecommunication systems are discussed. Some specific features of NGN are analyzed. There are given several examples of implementation of NGN into the telephone network of common use.
Keywords: telecommunication, common use, NGN network, convergence.
Summary
Solution of the problem of increasing the capacity of power system by using the matlab modeling
Mshvidobadze T.J.
Georgian Technical University
A mathematical model of power system was constructed. It included eight types of electric power plants essential for covering a deficit and bringing the generating capacities of the power system to the level which would provide its normal operation. The restrictions were stated in terms of inequalities, the efficiency function was chosen and the corresponding problem was solved by using the Matlab system- The obtained values of variables represented the values of generated capacities of appropriate power plants providing the minimum value of the efficiency function.
Keywords: electric power system, capacity, mathematical model, Matlab.
SUMMARY
Specific ffeatures of design of the inductor of magnetic transducer for direct control of the movement of jig-back aerial trAmway cars
Chunashvili B.M., Turdzeladze D.A., Tugushi M.A. and Khakhiashvili T.G.
Gerorgian Technical University
In modern systems controlling the electric drive of jig-back aerial tramways, magnetic transducers of direct position control are usually used for controlling the position of the car at its movement. The essential feature required of the transducer is that there be high accuracy of measurement, which is directly related to momentary generation of quite strong magnetic fields at relatively low consumption of electric power. The peculiarities of magnetization of the haulage rope are considered. The procedure of designing the parameters of induction systems of impulse magnetization are discussed..
Keywords: jig-back aerial tramway, magnetic transducer, car movement control, inductor.
Self-Induced torsional vibrations of the drill pipe string
Machabeli G.G., Mchedlishvili N.P. and Gelashvili G.O.
Georgian Technical University
Abstract. The reasons for occurrence of self-induced torsional vibrations of the drill pipe string were studied for choosing the efficient conditions of drilling and the design of the lower part of drill pipe string with the aim of reducing the dynamic load. The simulation flowchart was compiled with the help of program extension Simulink, and the problem was solved using software Matlab.
Keywords: drill pipe, drill pipe string, torsional vibrations, self-induced vibrations, drilling conditions.
summary
DETERMINATION OF STRESSES AT TORSIONAL VIBRATIONS OF THE DRILL PIPE STRING
Machabeli g.g., Mchedlishvili n.p. and Gelashvili G.O.
Georgian Technical University
The stresses at torsional vibrations of the drill pipe string were simulated using the Matlab software. It is demonstrated that, if the moment of inertia of gyrating mass on the pipe increases, relation b between the reduced moment of inertia I1 and the polar moment of inertia I0 of the pipe cross-section also increases, which results in a decrease in the stress of the string t. At the same time, if the moment of inertia I of the drill pipe string increases, i.e. the relation b decreases, the stress t also increases.
Keywords: drill pipe, drill pipe string, stress, torsional vibrations, simulation.
SUMMARY
Specific features of quality control of the average density of textile package winding
Nuriev M.N
Azerbaijan State Economic University, Baku
The basic methods of quality control of the average density of textile package winding were studied. It was revealed that these methods are rigidly adhered to a particular type of package and to the type of machine used. As a result, the regular control of average density of winding in industrial conditions of textile factories is not performed, and the reels have high nonuniformity in the winding density, which causes the increased percentage of wastes and the necessity in additional rewinding of the remained yarn from the reels.
Keywords: textile, package, winding, quality control
Summary
A system for transdermal delivery of medicines based on polysaccharide gel
Kharabadze M.G., Chichinadze N.M., Tsitlanadze G.V., Nadirashvili N.Sh. and Katsarava R.D.
Center of Medical Polymers and Biomaterials
Georgian Technical University
Transdermal delivery of medicines by using the therapeutic systems plays an important part in the treatment of rheumatic diseases. On the base of unsewed polysaccharide gel, a system of transdermal delivery of Diklofenak was designed. The system represents textile-sheathed gel plates, 30X10X0.3 cm. The clinical tests showed that 60-65% of Diklofenak penetrated through the skin in 24 hours. The system proved to be efficient for treatment of the diseases such as rheumatic arthritis and knee joint osteoarthrosis complicated by reactive synovitis. Improvements were observed in 67% of patients from the test group; 31% of patients did not feel any changes; ill effects (skin irritation) were revealed in 2% of patients.
Keywords: transdermal delivery, medicines, polysaccharide gel.
summary
ON THE ISSUE OF STABLE FUNCTIONING OF HYDROLOGIC SYSTEMS
OF MOUNTAINOUS REGIONS WITH CONSIDERATION OF THE
PECULIARITIES OF GEOECOLOGICAL CONDITIONS
Gobechia G.N., Tsereteli E.D. and Bondyrev I.V.
Scientific Center of Research of Productive Forces and Natural Resources of Georgia
Vakhushti Bagrationi Institute of Geography
Some issues of stable functioning of hydrologic systems of mountainous regions are discussed. Special consideration is given to the peculiarities of geoecological conditions that influence the stability of hydrologic systems and to the possible ways of preventing the adverse effects.
Keywords: hydrologic system, mountainous regions, geoecological conditions, stable functioning.
Summary
On the ways of preservation of water resources
Dolidze A.V.
Georgian Technical University
Possible ways of preservation of water resources are discussed. Usually, industrial water treatment plants provide the degree of purification of waste waters of 80-85%. A higher degree of water purification leads to the rise in price of water treatment. Taking into consideration this fact and the fact that the self-purification ability of hydrosphere as a whole and of its components approaches the limit, the requirements on wastes should be made stricter, a system of efficient monitoring of water quality should be designed, and “wet” production processes should be reduced sharply. Though the water resources are enormous and reproducible, they need proper management.
Keywords: water resources, preservation, water quality.
SUMMARY
ON THE PECULIARITIES OF WATER TREATMENT METHODS
Dolidze A.V., Makhashvili K.A. and Dolidze V.A.
Georgian Technical University
Various methods of water treatment and the peculiarities of their application are discussed. These methods include preliminary treatment, lime pretreatment, treatment using the poured filters, removal of dissolved impurities by filtration through industrial filters using the method of ion exchange, reverse osmosis, electrodialysis, complex treatment and others.
Keywords: water treatment, methods, peculiarities.
Summary
ALGEBRAIC – CHEMICAL INVESTIGATION OF SOME SILICON FTORIDES WITHIN THE SCOPE OF QUASI-ANB-MATRICES METHOD
Kupatadze N.O, Ovsianikova N.N, Markarashvili E.G, Gverdtsiteli M.I. and Megrelidze N.J.
Iv. Javakhishvili Tbilisi State University
Some silicon ftorides were investigated within the scope of quasi-ANB-matrices method. The diagonal elements of the quasi-ANB-matrix are the sums of atomic numbers of chemical elements, which are contained in some molecular structural fragments; the nondiagonal elements are the multiplicities of chemical bonds. Two correlation equations Tmelt.~
and Tboil.~
were constructed and investigated.
Keywords: quasi-ANB-matrix, silicon ftorides, correlation equations.
Algebraic-Chemical Investigation of Methyl Halides within Scope of The Quasi-ANB matrices Method
Lobzhanidze T.E., Kvernadze M.S. and Gverdtsiteli M.I.
Iv. Javakhishvili Tbilisi State University
Abstract: Methyl halides were investigated within the scope of the method of quasi-ANB-matrices. The diagonal elements of the quasi-ANB-matrix are the sums of atomic numbers of chemical elements, which the molecular structural fragments contain; the nondiagonal elements are the multiplicities of chemical bonds. Correlation equation “structure-properties” were constructed. The calculations showed that the correlation was good.
Keywords: quasi-ANB-matrix, methyl halides, correlation equations.
Summary
Contribution of Greek miners to the development of mining-metallurgical production in Georgia
Badzoshvili T.V., Inanishvili G.V. and Chagunava R.V.
Ferdinand Tavadze Institute of metallurgy and Materials Science
Anatholian Greeks had been known as skilled metallurgists from ancient times, and they had achieved fame in East World. With the aim of development of mining-metallurgical production in Georgia, King Erekle II (1720-1798) organized the transmigration of 800 families of Greek miners to Georgia. The Greek specialists managed to do the job - to lay the foundation for mining the minerals in Georgia, which promoted the improvements in the standard of life and the defensive capacity of the country.
Keywords: mining, minerals, history of mining, Greek miners.
summary
on king erekle II’s initiative to mine the minerals in Georgia
Badzoshvili T.V. , Chagunava R.V. and Inanishvili G.V.
Ferdinand Tavadze Institute of Metallurgy and Materials Science
King Erekle II (1720-1798) was both an outstanding military leader and a thoughtful monarch. His initiatives in the field of development of mining-metalurgical production in Georgia were of great importance for the country. By his order the local governors organized the collection of minerals and their delivery to the king. The collected samples were studied by A.Huldenshtedt, a well-known scientist. Then King Erekle II organized several expeditions with A.Huldenshtedt’s participation to the regions of interest.
Keywords: minerals, history of mining.
SUMMARY
ON THE RHEOLOGICAL CHARACHTERISTICS OF GROUND SPICERY
Mirazanashvili K.A. and Beruashvili G.S.
Georgian Institute of Food Industry
Georgian Technical University
By a special device of original design, the complex indices of the angle of repose of ground spicery and the utmost height of the upright free-standing wall were determined.
Keywords: spicery, ground spicery, angle of repose.
SuMmary
On the necessity in development of size – stoutness assortment of footwear for teenagers
Grdzelidze M.G.
Akaki Tsereteli State University, Kutaisi
The formation of human body takes place in childhood. For normal formation of teenager’s body and its particular parts, feet in our case, there should be established optimal conditions for normal formation of osseous system. To meet the demand for comfortable footwear for teenagers, it should be manufactured with consideration for stoutness and width of teenagers’ feet. The assortment with account for these basic size indices could satisfy the demand for comfortable shoes estimated 94% of teenagers.
Keywords: footwear, teenagers, feet, assortment.
SUMMARY
SPECIFIC FEATURES OF CONSTRUCTION OF SIZE-STOUTNESS ASSORTMENT OF FOOTWEAR FOR TEENAGERS
Grdzelidze M.G.
Akaki Tsereteli State University, Kutaisi
Footwear is comfortable if it is made according to rational size-stoutness assortment. Basing on numerous tests and statistical analyses, it was established that the length and the compass of the foot and its width in the outer bundle were the basic parameters to be taken into account at manufacturing the footwear. The correlation among these size indices allows processing the algorithm of two-factor regression. The obtained regression equation for each age class and age-gender group is adequate.
Keywords: footwear, teenagers, feet, assortment, experimental results, statistical calculation.