INTERIOR POINT PROJECTED REDUCED HESSIAN METHOD WITH TRUST REGION STRATEGY FOR NONLINEAR CONSTRAINED OPTIMIZATION

§1　IntroductionIn this paper we analyze an interior point scaling projected reduced Hessian methodwith trust region strategy for solving the nonlinear equality constrained optimizationproblem with nonnegative constraints on variables:min　f(x)s.t.　c(x) =0 (1.1)x≥0where f∶Rn→R is the smooth nonlinear function,notnecessarily convex and c(x)∶Rn→Rm(m≤n) is the vector nonlinear function.There are quite a few articles proposing localsequential quadratic programming reduced Hessian methods…     

Independent sets and 2‐factors in edge‐chromatic‐critical graphs

In 1968, Vizing made the following two conjectures for graphs which are critical with respect to the chromatic index: (1) every critical graph has a 2‐factor, and (2) every independent vertex set in a critical graph contains at most half of the vertices. We prove both conjectures for critical graphs with many edges, and determine upper bounds for the size of independent vertex sets in those graphs. © 2003 Wiley Periodicals, Inc. J Graph Theory 45: 113–118, 2004     

Temporal accuracy analysis of phase change convection simulations using the JFNK‐SIMPLE algorithm

The incompressible Navier–Stokes and energy conservation equations with phase change effects are applied to two benchmark problems: (1) non‐dimensional freezing with convection; and (2) pure gallium melting. Using a Jacobian‐free Newton–Krylov (JFNK) fully implicit solution method preconditioned with the SIMPLE (Numerical Heat Transfer and Fluid Flow. Hemisphere: New York, 1980) algorithm using centred discretization in space and three‐level discretization in time converges with second‐order accuracy for these problems. In the case of non‐dimensional freezing, the temporal accuracy is sensitive to the choice of velocity attenuation parameter. By comparing to solutions with first‐order backward Euler discretization in time, it is shown that the second‐order accuracy in time is required to resolve the fine‐scale convection structure during early gallium melting. Qualitative discrepancies develop over time for both the first‐order temporal discretized simulation using the JFNK‐SIMPLE algorithm that converges the nonlinearities and a SIMPLE‐based algorithm that converges to a more common mass balance condition. The discrepancies in the JFNK‐SIMPLE simulations using only first‐order rather than second‐order accurate temporal discretization for a given time step size appear to be offset in time. Copyright © 2007 John Wiley & Sons, Ltd.     

点可迁图中的正则因子

设图G是一个K-正则连通点可迁图.如果G不是极大限制性边连通的,那么G含有一个(k-1)-因子,它的所有分支都同构于同一个阶价于k和2k-3之间的点可迁图.此结果在某种程度上加强了Watkins的相应命题:如果k正则点可迁图G不是k连通的,那么G有一个因子,它的每一个分支都同构于同一个点可迁图.     

SiO2玻璃掺杂固溶半导体(ZnxCd1-xS)的光致发光研究

利用Sol-Gel工艺制备了掺杂固溶半导体ZnxCd1-xS的SiO2玻璃.吸收光谱研究表明材料的吸收边随Zn含量的增加而向短波方向移动;温度提高有利于生成较完整的晶粒.以短脉冲激光为激发光源对材料的光致发光效应作了分析,认为光致发光光谱是由电子与空穴复合发光和表面态与缺陷的复合发光组成,电子-空穴复合发光分布在较大的波长范围内,并且随Zn含量的增加向短波方向移动,材料热处理温度提高有助于降低表面态与缺陷的复合发光强度.     

正戊醛合成方法的改进

正戊醛合成方法的改进刘瑞蓝，南志祥，郭治安（西北大学化学系西安７１００６９）关键词正戊醛，一步氧化法，共沸蒸馏，精馏醛类化合物的使用相当广泛，尤其在香料工业中越来越受到人们重视，但由于易氧化与易聚合，在加热条件下合成难度大，产率低，我们在过去研究工作...     

A deconvolution‐based fourth‐order finite volume method for incompressible flows on non‐uniform grids

This paper is concerned with the development of a new high‐order finite volume method for the numerical simulation of highly convective unsteady incompressible flows on non‐uniform grids. Specifically, both a high‐order fluxes integration and the implicit deconvolution of the volume‐averaged field are considered. This way, the numerical solution effectively stands for a fourth‐order approximation of the point‐wise one. Moreover, the procedure is developed in the framework of a projection method for the pressure–velocity decoupling, while originally deriving proper high‐order intermediate boundary conditions. The entire numerical procedure is discussed in detail, giving particular attention to the consistent discretization of the deconvolution operation. The present method is also cast in the framework of approximate deconvolution modelling for large‐eddy simulation. The overall high accuracy of the method, both in time and space, is demonstrated. Finally, as a model of real flow computation, a two‐dimensional time‐evolving mixing layer is simulated, with and without sub‐grid scales modelling. Copyright © 2003 John Wiley & Sons, Ltd.     

Burst Assembly Schemes and Performance Evaluation in Optical Burst Switching Networks

1　Introduction　TheopticalInternethasbeenemergedasanefficientsolutionforsupportingever increasingInternettrafficbytakingadvantageofpotentiallyhugebandwidthofWavelength DivisionMultiplex (WDM )opticalnet works.Tomeettheincreasingbandwidthdemandsandreducecosts ,severalopticalnetwork paradigmshavebeenunderintensiveresearch .Ofalltheseparadigms,OpticalCircuitSwitching (OCS[1～ 3] )isrelativelyeasytoimplementbutlacksflexibilitytocopewiththefluc tuatingtrafficandthechanginglinkstate ,andrequi…     

An Efficient Two‐Step Paging Strategy Using Base Station Paging Agents in Mobile Communication Networks

An effective paging strategy is essential for improving the utility of radio channels. This paper proposes a two‐step paging strategy which involves using base station paging agents to page a single cell at each paging. An analytical model is used to evaluate the performance of the proposed strategy. The proposed strategy is compared with the traditional simultaneous paging strategy and a recent proposal using the base station paging agents. The numerical results showed that the proposed strategy proficiently reduces paging cost on radio channels compared with other paging strategies.     

Fluorescence probes as molecular weight detectors of polymers

It is shown that the relative intensity of the twisted intramolecular charge transfer (TICT) band of ester and benzonitrile derivatives of dialkylaniline in polymethylmethacrylate polymer matrices of different molecular weights (MW) to increase with increasing MW of the polymer. Our results emphasis the role of local free volumes (mobility in the matrix cage) and focus attention on the role of the MW of the polymer on the fluorescence of various TICT probes. These observations are confirmed by the red edge effect and fluorescence decay results.