论中古以来的异摄趋同现象

观察宋元时期的几种韵图,从中能清楚地看到宋元时期语言系统发生了很大的变化,其中异摄趋同现象是这时期最重要的变化之一,这时期比较系统、比较重要的异摄趋同有三对,即:江、宕二摄合流;梗、曾二摄合流;果、假二摄合流。通过对宋元时期的三种韵图——《四声等子》、《经史正音切韵指南》、《切韵指掌图》的分析以及其他文献材料来探讨异摄趋同现象,以此观测他们的演变轨迹。     

Attentional Load and the Reproduction of Physical Work

Abstract

The effect of attentional focus on the perception of physical work was examined by using a work reproduction design. Subjects performed a fixed interval of work at either 50 or 75% of their predicted VO₂ max, during which they were required either to solve a continuous flow of arithmetic problems or to perform in an unfilled control condition. On a subsequent trial, without a concomitant attention-demanding task, subjects were asked to reproduce the amount of work that they had previously performed. It was found that individuals in the control condition produced a significantly greater amount of work on the reproduction trial, while those in the attentional focus condition performed about the same amount as on the previous trial. No interaction was found between attentional focus and work load.     

Distributed anonymous data perturbation method for privacy-preserving data mining

Privacy is a critical requirement in distributed data mining. Cryptography-based secure multiparty computation is a main approach for privacy preserving. However, it shows poor performance in large scale distributed systems. Meanwhile, data perturbation techniques are comparatively efficient but are mainly used in centralized privacy-preserving data mining （PPDM）. In this paper, we propose a light-weight anonymous data perturbation method for efficient privacy preserving in distributed data mining. We first define the privacy constraints for data perturbation based PPDM in a semi-honest distributed environment. Two protocols are proposed to address these constraints and protect data statistics and the randomization process against collusion attacks： the adaptive privacy-preserving summary protocol and the anonymous exchange protocol. Finally, a distributed data perturbation framework based on these protocols is proposed to realize distributed PPDM. Experiment results show that our approach achieves a high security level and is very efficient in a large scale distributed environment.     

一种改进的摄动法对几个非线性方程的近似解析解的求解

提出了一种改进的摄动法,应用该方法对几个非线性方程（Riccati方程,mkdv方程,Blasius方程,对偶金兹堡朗道方程等）的求解,并与解析解或数值解进行了比较,该方法求解过程较为简洁。     

Asymptotic solution for a class of weakly nonlinear singularly perturbed reaction diffusion problem

Under appropriate conditions, with the perturbation method and the theory of differential inequalities, a class of weakly nonlinear singularly perturbed reaction diffusion problem is considered. The existence of solution of the original problem is proved by constructing the auxiliary functions. The uniformly valid asymptotic expansions of the solution for arbitrary mth order approximation are obtained through constructing the formal solutions of the original problem, expanding the nonlinear terms to the power in small parameter e and comparing the coefficient for the same powers of ε. Finally, an example is provided, resulting in the error of O(ε2).     

一类不确定非线性广义时滞系统的鲁棒控制与保性能控制

研究了不确定非线性结构扰动的广义系统的鲁棒控制和保性能控制问题．目的是分别设计系统的鲁棒控制器和保性能控制器。应用线性矩阵不等式方法,分别给出了系统的鲁棒控制器和保性能控制器存在的充分条件;并在这些条件可解时,分别给出了鲁棒控制器和保性能控制器的表达式。最后用例子说明了所给方法的应用．     

一类非线性扰动广义时滞系统的鲁棒保性能控制

研究了不确定非线性结构扰动的广义系统的鲁棒控制和保性能控制问题.为了分别设计系统的鲁捧控制器和保性能控制器,应用线性矩阵不等式方法.分别给出了系统的鲁棒控制器和保性能控制器存在的充分条件.并在这些条件可解时,分别给出了鲁棒控制器和保性能控制器的表达式.     

非简并微扰论中低能级修正与波函数修正之间的关系

介绍了非简并微扰中能级修正与波函数修正的由来,找出能量逐级修正与波函数逐级修正之间的关系。     

双参数奇摄动非线性系统边值问题

研究含积分算子并伴有边界摄动的双参数奇摄动非线性系统边值问题,在适当假设条件下,证明了解的存在并得到了解的关于双参数的双重渐近展开式。     

奇摄动非线性方程初值问题

研究伴有边界摄动的非线性方程μy＂＝f(t,y,εy＇)当μ＝O(ε^2)时的初始层性质，通过压缩映射，证明了解的存在，估计了余项。