The necessary and sufficient condition of the stability of linear nonautonomous system under the frequently-acting perturbation has been given and proved on the
In this paper,we study the existence unipueness and stability of the periodic solutionsfor fourth-order nonlinear nonhomogeneous periodic systems with slowly ch
In this paper a singularly perturbed linear second order hyperbolic problem with zerothorder reduced equation is discussed.Firstly,an energy inequality of the s
A 20-DOF hybrid stress element based upon Mindlin plate theory is developed usingthe optimization design method for thin and moderately thick plates.Numerical t
This paper establishes the finite element equation for the spherical shell.The resonantfrequencies of the above shell under different boundary conditions are al
In this paper,based on the step reduction method and exact analytic method,a new method,the exact element method for constructing finite element,is presented.Si