Recently, with the development of the computational implementation and the theoretical analysis of delay system, it’s shown that it would be more efficient to use DIDEs to simulate practical problems in the science engineering.

For aiming at the application of the seismic data processing, several basic time-frequency representations are presented entirely. The original derivation, basic principle and the computational implementation of S transform(ST) are introduced in detail.

In Chapter 2, we mainly introduce the density functional theory (DFT) as well as some popular ab initio software packages, which are our theoretical foundation and computational implementation to deal with the issues discussed in this thesis.

Abstract A computational implementation of Broyden family of variable metric methods was presented, in which the parameter θ had distinct valurs at various iterations and θ was made less than zero as far as possible Numerical resultsof solving some test problems by the algorithms with a few schemes for selecting θand the BFGS method were given for comparison to demonstrate that the algorithmis efficient for unconstrained optimization problems

Details of computational implementation and results are provided.

The basic problem with such conditions involves the computational implementation of the derived results.

This new "general-s" formalism is found to be highly suitable for a computational implementation, and the technical details of this implementation are given.

I describe in detail a computational implementation which has worked reasonably well in practice.

This paper describes the formulation of a nonlinear mixed integer programming model for a large-scale product development and distribution problem and the design and computational implementation of a special purpose algorithm to solve the model.

A new method called Character Slater Determinant CI(CDCI) and its computational implementation are presented in order to simplify electron correlation calculation. The accuracy and reliability of the present method are tested with several diatomic molecules and atoms. The calculational accuracy is comparable to the CISD method of G94,indicating that the method is acceptable and the correspondent program is accurate. On the other hand,the present method results in molecular properties(bong lengths,bond...

A new method called Character Slater Determinant CI(CDCI) and its computational implementation are presented in order to simplify electron correlation calculation. The accuracy and reliability of the present method are tested with several diatomic molecules and atoms. The calculational accuracy is comparable to the CISD method of G94,indicating that the method is acceptable and the correspondent program is accurate. On the other hand,the present method results in molecular properties(bong lengths,bond energies and force constants) that are considerably closer to experimental values than those obtained with Hartree-Fock SCF method.

Abstract A computational implementation of Broyden family of variable metric methods was presented, in which the parameter θ had distinct valurs at various iterations and θ was made less than zero as far as possible Numerical resultsof solving some test problems by the algorithms with a few schemes for selecting θand the BFGS method were given for comparison to demonstrate that the algorithmis efficient for unconstrained optimization problems

The unified strength theory is completely a new system of yield and failure of materials under the complex stress state. It embraces many well established criteria as its special or asymptotic cases, such as the Tresca (1864), the Mises (1913), and the Mohr Coulomb (lower bound,1900), as well as the twin shear strength theory ( upper bound, Yu 1985). The unified strength theory forms an entire spectrum of convex and non convex criteria, which can be used to describe many kinds of engineering materials. It...

The unified strength theory is completely a new system of yield and failure of materials under the complex stress state. It embraces many well established criteria as its special or asymptotic cases, such as the Tresca (1864), the Mises (1913), and the Mohr Coulomb (lower bound,1900), as well as the twin shear strength theory ( upper bound, Yu 1985). The unified strength theory forms an entire spectrum of convex and non convex criteria, which can be used to describe many kinds of engineering materials. It has been studied and applied in the researches of applied mechanics and analyses of engineering structures. Various criteria of the unified strength theory are the piecewise linear criteria. The forms of limit surface of the unified strength theory are angular. A single smooth surface can be developed to approximate to all the piecewise linear criteria of the unified strength theory. However, the non linear mathematical expressions of the smooth curves are difficult for application to analytic solution of plastic analysis of structures. The piecewise linear expressions of the unified strength theory are convenient for analytic solution of the plastic problems. The singularity at the corners of the unified strength theory has been overcome by using a simple and unified manner. It is convenient for computational implementation.