Matching Boundary Conditions for a Heterogeneous Atomic Chain

We propose accurate boundary treatments for a heterogeneous atomic chain, in terms of matching boundary conditions （MBCs）. The main challenge lies in reproducing the physical reflection across the boundary to a correct amount. With reflection coefficients we demonstrate that the accuracy is improved when more atoms are used under the boundary condition. The inclusion of an atom in the embedded sublattice B may considerably enhance the performance. Numerical testing illustrates the effectiveness of the proposed MBCs.

Stability of Atomic Simulations with Matching Boundary Conditions

.We explore the stability of matching boundary conditions in one space dimension,which were proposed recently for atomic simulations(Wang and Tang,Int.J.Numer.Mech.Eng.,93(2013),pp.1255–1285).For a finite segment of the linear harmonic chain,we construct explicit energy functionals that decay along with time.For a nonlinear atomic chain with its nonlinearity vanished around the boundaries,an energy functional is constructed for the first order matching boundary condition.Numerical verifications are also presented.

Matching Boundary Conditions for Scalar Waves in Body-Centered-Cubic Lattices

Matching boundary conditions(MBC’s)are proposed to treat scalar waves in the body-centered-cubic lattices.By matching the dispersion relation,we construct MBC’s for normal incidence and incidence with an angle a.Multiplication of MBC operators then leads to multi-directional absorbing boundary conditions.The effectiveness are illustrated by the reflection coefficient analysis and wave packet tests.In particular,the designed M1M1 treats the scalar waves in a satisfactory manner.

THE EXACT SOLUTIONS OF ELASTIC－PLASTIC CRACK LINE FIELD FOR MODE Ⅱ PLANE STRESS CRACK

The near crack line field analysis method has been used io investigate into theexact elastic-plastic solutions of a mode II crack under plane stress condilion in anelastic-perfectly plastic solid. The assumptions of the usual small scale yielding theory.hare been completely. dbandoned and the correct formulations of matching conditionsat the elaslic-plastic boundary. have been given. By, matching the general solution ofthe plastic slress field (bul not the special solution used to be adopted) with the exactelastic stress field (but not the crack tip K-dominant field) at the elastic-plasticboundary, near the crack line, the plastic stresses. the length of the plastic =one and theunit normal vector of the elastic-plastic boundary.which are sufficiently precise near the crack line region ,have been given.

THE EXACT SOLUTIONS OF ELASTIC－PLASTIC CRACK LINE FIELD FOR MODE Ⅱ PLANE STRESS CRACK

The near crack line field analysis method has been used to investigate into the exact elastic-plastic solutions of a mode Ⅱ crack under plane stress condition in anelastic-perfectly plastic solid. The assumptions of the usual small scale yielding theoryhave been completely. dbandoned and the correct .formulations of matching conditionsat the elastic-plastic boundary have been given. By matching the general solution of the plastic stress field (but not the special solution used to be adopted) will the exactelastic stress field (but not the crack tip K-dominant field) at the elastic-plasticboundary. near the crack line, the plastic .stresses, the length of the plastic zone and theunit normal vector of the elaslic-plastic boundary. which sufficiently precise nearthe crack line region, hare been given.

An Efficient Multi-area Networks-Merging Model for Power System Online Dynamic Modeling

To improve accuracy and efficiency in power systems dynamic modeling,the distributed online modeling approach is a good option.In this approach,the power system is divided into sub-grids,and the dynamic models of the sub-grids are built independently within the distributed modeling system.The subgrid models are subsequently merged,after which the dynamic model of the whole power system is finally constructed online.The merging of the networks plays an important role in the distributed online dynamic modeling of power systems.An efficient multi-area networks-merging model that can rapidly match the boundary power flow is proposed in this paper.The iterations of the boundary matching during network merging are eliminated due to the introduction of the merging model,and the dynamic models of the sub-grid can be directly“plugged in”with each other.The results of the calculations performed in a real power system demonstrate the accuracy of the integrated model under both steady and transient states.

Edge-Oriented Spatial Interpolation for Error Concealment of Consecutive Blocks

This paper proposes a low-complexity spatial-domain error concealment （EC） algorithm for recovering consecutive blocks error in still images or intra-coded （I） frames of video sequences. The proposed algorithm works with the following steps. Firstly the Sobel operator is performed on the top and bottom adjacent pixels to detect the most probable edge direction of current block area. After that one-dimensional （1-D） matching is used on the available block boundaries. Displacement between edge direction candidate and most probable edge direction is taken into consideration as an important factor to improve stability of 1-D boundary matching. Then the corrupted pixels are recovered by linear weighting interpolation along the estimated edge direction. Finally the interpolated values are merged to get last recovered picture. Simulation results demonstrate that the proposed algorithms obtain good subjective quality and higher PSNR than the methods in literatures for most images.