Overview of Moving Particle Semi-implicit Techniques for Hydrodynamic Problems in Ocean Engineering

With the significant development of computer hardware,many advanced numerical techniques have been proposed to investigate complex hydrodynamic problems.This article aims to provide a detailed review of moving particle semi-implicit(MPS)techniques and their application in ocean and coastal engineering.The achievements of the MPS method in stability and accuracy,boundary conditions,and acceleration techniques are discussed.The applications of the MPS method,which are classified into two main categories,namely,multiphase flows and fluid-structure interactions,are introduced.Finally,the prospects and conclusions are highlighted.The MPS method has the potential to solve practical problems.

MULTI-PARAMETER ACCELERATED MODIFIED NEWTON-RAPHSON METHODS FOR RIGIDPLASTIC FE ANALYSIS

Applications of certain multi-parameter acceleration techniques used with themodified New-ton-Raphson (mN-R) methods to solve the nonlinear equations arising from rigid-plasticfinite element analysis are investigated. New modified multi-parameter techniques, developed fromCrisfield's multi-parameter methods, are utilized to solve these nonlinear equations. The numericalperformance of these techniques is compared with the standard Newton-Raphson method (sN-R),Crisfield's single parameter method (C1), Crisfield's two parameter method (C2) and Crisfield'sthree parameter method (C3). The new techniques do not involve additional residual force calculationand require little extra computational effort. In addition, they are more robust and efficient thanother existing acceleration techniques.

Growth and Properties of Mid-infrared Single Crystal LiInS_2

A Bridgman growth furnace was modified by adding adiabatic material between two furnace tubes. The appropriate temperature gradient of 10-30 ℃/cm at the growth interface was obtained by adjusting the distance between the two sections and controlling their temperature. The infrared nonlinear optical （NLO） crystal LiInS2 was successfully grown by the accelerated crucible rotation technique （ACRT）. The crystal was characterized by using XRD and transmission microscopy. It is found that the UV-VIS-NIR and Mid-IR transmittances are about 40%.

EXPERIMENTAL RESEARCH ON DIRECTIONAL SOLIDIFICATION OF Al－4．5wt％Cu ALLOY BY ACRT METHOD

Accelerated crucible rotation technique(ACRT) has been used for the directional solidification of Al-4.5wt% Cu binary alloy.By rotating the crucible at varying rate and direction,forced liquid flows are aroused These flows include Ekman flow,Couette flow and Spiral Shear flow.Especially,Ekman flow acts directly at the L/S interface,changes diffusion and heat exchange conditions and has strong influences on the morphology of L/S interface.Experimental results show that,compared with normal Bridgman specimens,the solidification region is much narrower and the cell spacing is much smaller in ACRT specimens.These influences become much stronger when the accelerating rate is increased.

ACCELERATED SYMMETRIC ADMM AND ITS APPLICATIONS IN LARGE-SCALE SIGNAL PROCESSING

The alternating direction method of multipliers(ADMM)has been extensively investigated in the past decades for solving separable convex optimization problems,and surprisingly,it also performs efficiently for nonconvex programs.In this paper,we propose a symmetric ADMM based on acceleration techniques for a family of potentially nonsmooth and nonconvex programming problems with equality constraints,where the dual variables are updated twice with different stepsizes.Under proper assumptions instead of the socalled Kurdyka-Lojasiewicz inequality,convergence of the proposed algorithm as well as its pointwise iteration-complexity are analyzed in terms of the corresponding augmented Lagrangian function and the primal-dual residuals,respectively.Performance of our algorithm is verified by numerical examples corresponding to signal processing applications in sparse nonconvex/convex regularized minimization.

AN ACCELERATED WAVEFORM RELAXATION APPROACH BASED ON MODEL ORDER REDUCTION FOR LARGE COUPLING SYSTEMS

In this paper, we present an accelerated simulation approach on waveform relaxation using Krylov subspace for a large time-dependent system composed of some subsystems. This approach first allows these subsystems to be decoupled by waveform relaxation. Then the Arnoldi procedure based on Krylov subspace is provided to accelerate the simulation of the decoupled subsystems independently. For the new approach, the convergent conditions on waveform relaxation are derived. The robust behavior is also successfully illustrated via numerical examples.