共查询到20条相似文献,搜索用时 15 毫秒
1.
E. V. Zakharov S. N. Levchenko Yu. Ya. Kharlanov 《Computational Mathematics and Modeling》1997,8(3):282-287
The article considers the mathematical model of a lens antenna in the shape of a homogeneous dielectric torus excited by an
axial magnetic dipole. The boundary-value problem for an elliptical differential equation is posed and reduced by the fundamental
solution method to an integral equation of 2nd kind over the torus section. A numerical algorithm is proposed, and the numerical
results are compared with experimental findings.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 109–115. 相似文献
2.
An algorithm is proposed to find the constrained minimum of a function. The algorithm uses differential equations that incorporate
the problem constraints as singular manifolds.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 48–51. 相似文献
3.
The direct solution of the vertical electrical sounding problem is considered for three-dimensional quasilayered media. An
efficient fast algorithm is obtained for computing the apparent resistivity curves in the two-dimensional case. A PC implementation
of the algorithm is proposed.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 123–131. 相似文献
4.
V. I. Dmitriev 《Computational Mathematics and Modeling》1997,8(3):270-277
We consider the inverse sounding problem for a stratified medium using the variable magnetic field of a loop. A uniqueness
theorem and a theorem ensuring stable determination of the integral conductivity of the medium are proved. An algorithm is
proposed for the solution of the inverse problem based on a transformation from the time domain to the frequency domain.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 87–95. 相似文献
5.
E. E. Malyutina 《Computational Mathematics and Modeling》1999,10(4):393-404
A genetic algorithm is applied to compute the control of a complex dynamic system. Methods are proposed to modify the genetic
algorithm so as to adapt it to variation of the objective function. Comparison with dynamic programming results is carried
out.
The study was supported by the Russian Foundation of Basic Research (grant No. 9607-89110) and Ministry of Science (grants
0201.03.002 and 0201.03.003).
Translated from Chislennye Metody i Vychislitel'nyi Eksperiment, Moscow State University, pp. 82–96, 1998. 相似文献
6.
A simple mathematical model of the motion of a parachute system in space is described and an interactive algorithm for parametric identification of the model is proposed. The algorithm selects the model parameters that minimize the deviation of the calculated dependences from experimental observations on the computer graphic monitor.Moscow. Translated from Dinamicheskie Sistemy, No. 10, pp. 106–111, 1992. 相似文献
7.
The article considers the determination of the solution-dependent coefficient of a nonautonomous ordinary differetial equation
with a parameter. Reduction of the inverse problem to a nonlinear operator equation is used to prove existence and uniqueness
theorems and to propose an iterative solution method.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 5–17. 相似文献
8.
The inverse problem of electromagnetic sounding of the shape of a conducting body is considered in the framework of the two-dimensional
model with E-polarization, assuming a cylindrical body of an arbitrary cross section embedded in a layered medium. The integral
equations are obtained for the case of an ideally conducting body and a body of finite conductivity. The linearization method
is applied to obtain an iterative method that finds a correction to the initial shape.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 96–103. 相似文献
9.
Search for optimal routing (in the game-theoretical sense) in a packet data transmission network is considered. The proposed
method reduces the general problem to a particular problem of routing in ring networks. A fast parallel (distributed) algorithm
is constructed, which may be used in network-level data transmission protocols.
Translated from Chislennye Metody i Vychislitel'nyi Eksperiment, Moscow State University, pp. 107–123, 1998. 相似文献
10.
The article solves the problem of compressible nonviscous gas flow inside a cylindrical channel in the presence of a source
on the channel axis. The cases considered include a supersonic spherically symmetrical source and a hypersonic source modeling
jet flow. The numerical solution is obtained by two methods: one method treats the flow singularities (shocks, etc.) in explicit
form, while the other uses the “through calculation” procedure. The solution is applied to analyze the physical flow pattern
and the distribution of gasdynamic parameters in the shock layer, in particular on the channel walls.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 169–180. 相似文献
11.
The article considers the construction of a stable approximation of the basic component in an experimental spectrum. Conditions
of independence and nondegeneracy are introduced for the local resonance nonhomogeneities and the basic component, which is
treated as a continuous smooth function whose local variation is substantially less than the variation of the local nonhomogeneities.
The problem of approximating the basic component is shown to have a unique solution under these conditions. A stable algorithm
is developed for the construction of the basic component. The algorithm is applied to construct the basic component from typical
spectrometric data, and the results are compared with other known basic-component fitting methods.
Translated from Chislennye Metody v Matematicheskoi Fizike, Published by Moscow University, Moscow, 1996, pp. 137–146. 相似文献
12.
A method of calculating a viscoelastic shock-absorbing device or structure by the method of averaging systems of integro-differential equations is considered. The principal quadratic theory of hereditary viscoelasticity is used as the physical relationship between forces and displacements of the shock-absorbing base or structure.Moscow Institute of Electronic Machine Construction. Translated from Mekhanika Polimerov, No. 4, pp. 730–737, July–August, 1972. 相似文献
13.
The paper considers the problem of determining the velocities of targets in the atmosphere given a set of Doppler spectra produced by continuous Doppler systems. The problem of determining the velocities of particles moving in a closed trajectory (a circle) is examined. A uniqueness theorem is proved for the reconstruction of velocities from two spectra. An algorithm is proposed for determining the sought function, and a numerical experiment is conducted to establish its efficiency.Translated from Matematicheskie Modeli Estestvoznaniya, Published by Moscow University, Moscow, 1995, pp. 162–167. 相似文献
14.
F. V. Rass 《Mechanics of Composite Materials》1996,32(4):364-367
The stability of the outer nonmetallic layer of a triple-layer rod with foam core was studied both experimentally and theoretically by the energy balance method. The buckling of the outer layer occurs by a sudden transition to a nonadjacent equilibrium form and this process should be seen in regard to a set of deformational factors.Moscow State University for Ecology and Environmental Studies, Moscow, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 32, No. 4, pp. 525–530, July–August, 1996. 相似文献
15.
An algorithm is proposed to construct a sequence of evolutionary adaptive grids, each consisting of segments of uniform grids
compatible with the Richardson extrapolation procedure. The necessary numerical accuracy is achieved by using Richardson's
extrapolation method to increase the accuracy of the difference solution and by controlling the nonhomogeneity parameter on
passing from one segment to the next. The numerical model used in the article is the diffusion-convection equation, whose
solution contains large gradients. Numerical calculations show that the algorithm attains the prespecified accuracy on a nonuniform
difference grid. Numerical examples support the universality of the proposed algorithm. High accuracy results can be obtained
without changing the structure of the difference schemes approximating the original problem; only the grid spacing has to
be changed.
Translated from Chislennye Metody v Matematicheskoi Fizike, Moscow State University, pp. 22–36, 1998. 相似文献
16.
D. S. Filippychev 《Computational Mathematics and Modeling》1997,8(2):135-143
We consider the behavior of a plasma bounded in the longitudinal direction by absorbing walls. The model contains charged
particles (electrons and ions) moving in the direction of an external magnetic field with two velocity components: longitudinal
and transverse. The charged particles are created in pairs by a distributed source. The working model is based on the electrostatic
“particles in a cell” method augmented by Emmert's model for a volume source and a model of binary Coulomb particle collisions
using the Monte Carlo method. Calculation results are reported for a model with electron-ion collisions and for a collisionless
plasma model.
Translated from Chislennye Metody v Matematicheskoi Fizike, Published by Moscow University, Moscow, 1996, pp. 100–109. 相似文献
17.
T. V. Amochkina A. S. Antipin F. P. Vasil'ev 《Computational Mathematics and Modeling》1997,8(4):314-321
The article considers the variable-metric continuous proximal method for the convex programming problem. The convergence of
the method is proved. The regularized version of the method is proposed for the case where the objective function and the
feasible set are defined inexactly. A regularizing operator is constructed.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 39–47. 相似文献
18.
V. F. Apel'tsin 《Computational Mathematics and Modeling》1997,8(4):369-384
An incomplete Galerkin projection method is constructed and proved as a generalization of the Sommerfeld method for the problem
of plane diffraction of the field of a point source on an ideally conducting circular cylinder coated by a thin homogeneous
dielectric layer with an arbitrary boundary, in the H-polarization case. An explicit asymptotic solution is obtained in the
form of a generalized Watson series. Specific eesonance phenomena are investigated for a boundary layer with corner points.
Translated from Obratnye Zadachi Estestvoznaniya, Published by Moscow University, Moscow, 1997, pp. 132–149. 相似文献
19.
V. I. Matyash 《Mechanics of Composite Materials》1971,7(6):957-961
The method of averaging is used to investigate the flutter of a viscoelastic plate. It is shown that taking the viscous drag into account leads to a reduction of the critical velocity.Moscow Institute of Geodetic and Aerial Photography and Cartographic Engineers. Translated from Mekhanika Polimerov, No. 6, pp. 1077–1083, November–December, 1971. 相似文献
20.
A new method is proposed and investigated for solving the inverse three-dimensional problem of magnetotelluric sounding. The method uses the tangential electric field on the Earth's surface, which is synthesized from the known impedance.Translated from Matematicheskie Modeli Estestvoznaniya, Published by Moscow University, Moscow, 1995, pp. 115–121. 相似文献