共查询到20条相似文献,搜索用时 15 毫秒
1.
Chau O. Shillor M. Sofonea M. 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,55(1):32-47
A model for the dynamic, adhesive, frictionless contact
between a viscoelastic body and a deformable foundation is
described. The adhesion process is modeled by a bonding field on
the contact surface. The contact is described by a modified normal
compliance condition. The tangential shear due to the bonding
field is included. The problem is formulated as a coupled system
of a variational equality for the displacements and a differential
equation for the bonding field. The existence of a unique weak
solution for the problem is established, together with a partial
regularity result. The existence proof proceeds by construction of
an appropriate mapping which is shown to be a contraction on a
Hilbert space. 相似文献
2.
《Journal of Applied Mathematics and Mechanics》2006,70(4):599-610
The torsion of a composite cone that has a centre of rotation at its apex is investigated in a spherical system of coordinates. A composite cone is a cone with one shear modulus, inserted into a conical funnel having another shear modulus and with ideal mechanical contact between its surface and the inner surface of the conical funnel. The auxiliary problem of a composite cone with its apex truncated by a spherical surface is considered first. The outer surface of such a conical body is not loaded, but a load that reduces to a torque is applied to its spherical surface. The auxiliary problem is reduced to a one-dimensional discontinuous boundary-value problem using a specially constructed integral transformation. The exact solution of this boundary-value problem is constructed. The limit is then taken in the solution obtained as the radius of the spherical surface tends to zero for the purpose of obtaining an exact solution of the problem of the torsion of a composite cone that has a centre of rotation at the apex. 相似文献
3.
An adaptive refinement procedure consisting of a localized error estimator and a physically based approach to mesh refinement is developed for the finite difference method. The error estimator is a variation of a successful finite element error estimator. The errors are estimated by computing an error energy norm in terms of discontinuous and continuous stress fields formed from the finite difference results for plane stress problems. The error measure identifies regions of high error which are subsequently refined to improve the result. The local refinement procedure utilizes a recently developed approach for developing finite difference templates to produce a graduated mesh. The adaptive refinement procedure is demonstrated with a problem that contains a well-defined singularity. The results are compared to finite element and uniformly refined finite difference results. 相似文献
4.
《Nonlinear Analysis: Real World Applications》2007,8(1):288-294
The existence of an energy minimizer relative to a class of rearrangements of a given function is proved. The minimizers are stationary and stable solutions of the two-dimensional barotropic vorticity equation, governing the evolution of geophysical flow over a surface of variable height. The theorem proved implies the existence of a family of stable anticyclonic vortices with cyclonic potential vorticity over a seamount, and a corresponding family of cyclonic vortices with anticyclonic potential vorticity over a localized depression. The seamount is described by a characteristic function (corresponding to a flat top) with arbitrary shape. 相似文献
5.
A bayesian approach to binary response curve estimation 总被引:1,自引:0,他引:1
Makio Ishiguro Yosiyuki Sakamoto 《Annals of the Institute of Statistical Mathematics》1983,35(1):115-137
Summary The purpose of the present paper is to propose a practical procedure for the estimation of the binary response curve. The
procedure is based on a model which approximates the response curve by a finely segmented piecewise constant function. To
obtain a stable estimate we assume a prior distribution of the parameters of the model. The prior distribution has several
parameters (hyper-parameters) which are chosen to minimize an information criterion ABIC. The procedure is applicable to data
consisting of observations of a binary response variable and a single explanatory variable. The practical utility of the procedure
is demonstrated by examples of applications to the dose response curve estimation, to the intensity function estimation of
a point process and to the analysis of social survey data. The application of the procedure to the discriminant analysis is
also briefly discussed.
The Institute of statistical mathematics 相似文献
6.
《Journal of Applied Mathematics and Mechanics》2003,67(3):461-468
The problem of the uniform heating of a two-layer plate is solved. The transversely isotropic layer considered (a soft plate) is in ideal contact with a rigid isotropic thin elastically deformed layer. The ends of the plate are load-free. A boundary layer of the soft plate (a thin contact layer) is introduced, which enables the boundary conditions on the ends of the plate to be formulated in such a way that the problem has a bounded smooth solution [1]. The two-layer plate, generally speaking, is bounded along the axis perpendicular to the axes directed along the length and thickness of the plate. The resultant force and the resultant moment, applied to the end transverse sections, are equal to zero. The exact solution of the temperature problem is sought using the equations of the theory of elasticity. The plane problem of the bending of a two-layer plate acted upon by a uniformly distributed pressure applied to the side surface of an anisotropic layer is solved by a similar method. The ends of the rigid isotropic layer are clamped. 相似文献
7.
N.C. Apreutesei 《Nonlinear Analysis: Real World Applications》2012,13(3):1391-1400
The paper is devoted to an optimal control problem for a system of three nonlinear parabolic equations from population dynamics. The equations model a trophic chain consisting of a predator, a pest and a plant species. The existence and uniqueness of the positive solution for the system are proved. The control variable is connected with the action of a pesticide. Our goal is to minimize the density of the pest and to maximize the plant density. The existence of the optimal solution is proved. The first and second order optimality conditions are established. 相似文献
8.
9.
Jaewook Lee 《Journal of Global Optimization》2007,38(1):61-77
A new deterministic method for solving a global optimization problem is proposed. The proposed method consists of three phases.
The first phase is a typical local search to compute a local minimum. The second phase employs a discrete sup-local search
to locate a so-called sup-local minimum taking the lowest objective value among the neighboring local minima. The third phase
is an attractor-based global search to locate a new point of next descent with a lower objective value. The simulation results
through well-known global optimization problems are shown to demonstrate the efficiency of the proposed method. 相似文献
10.
《Mathematical and Computer Modelling》1997,25(11):1-7
The mathematical analysis of a model for substrate concentration in tissue is presented. The model consists of a single capillary from which substrate diffuses into a surrounding cylinder of tissue. The substrate is consumed at a rate proportional to the amount present. The results correlate well with those obtained from a similar model with a constant consumption rate. 相似文献
11.
Andrzej Kosior Ph. D 《PAMM》2005,5(1):99-100
This paper presents the results of tests on free and forced harmonic vibrations in a system with two beams with structural friction taken into account. The beams are clamped together with uniform unitary pressure. The hysteresis loop describing the frictional-elastic properties of the system has a form of a parallelogram. The autor created a mathematical model of the vibrating system with two beams. During free vibrations of the system, its damping characteristics were tested by a digital simulation method. The vibration damping decrement as a function of amplitude displacement was determined. When vibrations were harmonically forced, the amplitude - frequency characteristics of the system were determined numerically. The system was used as a nonlinear vibration damper in a linear system with a harmonic force. The equations of motion of the nonlinear two-degree of freedom system were solved by means of a digital simulation method. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
12.
V. A. Titarev E. M. Shakhov 《Computational Mathematics and Mathematical Physics》2010,50(12):2131-2144
The nonisothermal steady rarefied gas flow driven by a given pressure gradient (Poiseuille flow) or a temperature gradient
(thermal creep) in a long channel (pipe) of an arbitrary cross section is studied on the basis of the linearized kinetic S-model. The solution is constructed using a high-order accurate conservative method. The numerical computations are performed
for a circular pipe and for a cross section in the form of a regular polygon inscribed in a circle. The basic characteristic
of interest is the gas flow rate through the channel. The solutions are compared with previously known results. The flow rates
computed for various cross sections are also compared with the corresponding results for a circular pipe. 相似文献
13.
The present paper investigates phenomena brought about into the classic peristaltic mechanism by inclusion of non-Newtonian effects through a porous space in a channel. The peristaltic motion of a second-order fluid through a porous medium was studied for the case of a planar channel with harmonically undulating extensible walls. The system of the governing nonlinear PDE is solved by using the perturbation method to second-order in dimensionless wavenumber. The analytic solution has been obtained in the form of a stream function from which the axial pressure gradient has been derived. The flow is investigated in a wave frame of reference moving with velocity of the wave. Numerical calculations are carried out for the pressure rise and frictional force. The features of the flow characteristics are analyzed by plotting graphs and discussed in detail. 相似文献
14.
R. Alonderis 《Lithuanian Mathematical Journal》2008,48(2):123-136
The paper deals with a coding method for a sequent calculus of the propositional logic. The method is based on the sequent
calculus. It allows us to determine if a formula is derivable in the calculus without constructing a derivation tree. The
main advantage of the coding method is its compactness in comparison with derivation trees of the sequent calculus. The coding
method can be used as a decision procedure for the propositional logic. 相似文献
15.
V. N. Rubanovskii 《Journal of Applied Mathematics and Mechanics》1988,52(6):710-714
The set of relative equilibria of a satellite-gyrostat in a Newtonian gravitational field is studied. The simple geometrical form of this set is described. The branching and stability of the equilibria of a symmetric gyrostat are considered. The results are represented by bifurcation diagrams, on which the degree of stability of the equilibria is distributed in accordance with a law whereby the stability changes at a fixed value of the gyrostatic moment. 相似文献
16.
Janusz Kacprzyk 《Fuzzy Sets and Systems》1978,1(3):169-179
The multistage control of a deterministic and stochastic system in a fuzzy environment is considered. The fuzzy environment is meant as fuzzy constraints imposed on subsequent controls and a fuzzy goal to be attained. The fuzzy decision is assumed to be the intersection of fuzzy constraints and a fuzzy goal. The problem is to find a maximizing decision. The termination time is given as a specified fuzzy set in the space of control stages. For solving the problem, the dynamic programming is applied. 相似文献
17.
The paper considers a one-dimensional particle-continuum model, with impulsive interaction between the fluid and a number of pointwise particles. A simplification results in a system of ODEs coupled with a parabolic PDE forced by a nonlinear term involving a sum of Dirac delta functions. The existence of a mild solution is proved using a combination of energy estimates and semigroup theory. However, the regularity of these solutions is shown to be limited to C0,1 by the impulsive terms. The convergence of a Galerkin method is established simultaneously with a proof of continuous dependence, and thus uniqueness, of solutions for the underlying system. The peculiarities of the system imply this analysis must be performed in L∞. The C0,1 regularity of the solution determines a suboptimal rate of convergence for the Galerkin method. The theoretical results are verified by MATLAB computations. 相似文献
18.
The wheel graph is the join of a single vertex and a cycle, while the fan graph is the join of a single vertex and a path.
The resistance distance between any two vertices of a wheel and a fan is obtained. The resistances are related to Fibonacci
numbers and generalized Fibonacci numbers. The derivation is based on evaluating determinants of submatrices of the Laplacian
matrix. A combinatorial argument is also illustrated. A connection with the problem of squaring a rectangle is described. 相似文献
19.
Given any two-dimensional and incompressible flow describedby a set of linear partial differential equations, a methodis presented for determining the solution for the dependentvariables (velocity, pressure, etc.). The method is then usedto investigate the following magnetohydrodynamic flows. (a) The flow of an irrotational and inviscid fluid. (b) The flow of a viscous fluid. (c) The flow of an electrically conducting, inviscid fluid inthe presence of a magnetic field aligned with the flow at infinity. (d) The flow of an electrically conducting, viscous fluid inthe presence of a magnetic field having arbitrary direction. 相似文献
20.
This paper considers the problem of consumption and investment in a financial market within a continuous time stochastic economy. The investor exhibits a change in the discount rate. The investment opportunities are a stock and a riskless account. The market coefficients and discount factor switch according to a finite state Markov chain. The change in the discount rate leads to time inconsistencies of the investor’s decisions. The randomness in our model is driven by a Brownian motion and a Markov chain. Following Ekeland and Pirvu (2008) we introduce and characterize the subgame perfect strategies. Numerical experiments show the effect of time preference on subgame perfect strategies and the pre-commitment strategies. 相似文献