A regression approach to ROC surface, with applications to Alzheimer’s disease

We consider the estimation of three-dimensional ROC surfaces for continuous tests given covariates.Three way ROC analysis is important in our motivating example where patients with Alzheimer’s disease are usually classified into three categories and should receive different category-specific medical treatment.There has been no discussion on how covariates affect the three way ROC analysis.We propose a regression framework induced from the relationship between test results and covariates.We consider several practical cases and the corresponding inference procedures.Simulations are conducted to validate our methodology.The application on the motivating example illustrates clearly the age and sex effects on the accuracy for Mini-Mental State Examination of Alzheimer’s disease.     

Global exact boundary observability for first‐order quasilinear hyperbolic systems of diagonal form

In this paper, by means of a constructive method based on the theory of the existence and the uniqueness of the C¹ solution to the Cauchy problem and the Goursat problem, the global exact boundary observability for the first‐order quasilinear hyperbolic systems of diagonal form with linearly degenerate characteristics is obtained. In the case that the system has no zero characteristics, we realize the two‐sided and one‐sided global exact boundary observability by the boundary observed values and obtain the observability inequality. Copyright © 2012 John Wiley & Sons, Ltd.     

磁浮列车的动力稳定性分析与Liapunov指数

针对弹性轨道上的磁悬浮列车线动力控制系统,给出了采用Ｌｉａｐｕｎｏｖ特性指数送别动力系统稳定性的判据：当动力系统的全部Ｌｉａｐｕｎｏｖ特性指数小于零时,动力控制系统是稳定的;而当动力系统有一Ｌｉａｐｕｎｏｖ特性指数大于零时,动力系统就成为不稳定的,由于Ｌｉａｐｕｎｏｖ特性指数可以由数值积分方式方便地给出,这一判断方法对于不便搜索参数稳定区域的高维动力系统,与寻求周期变系数线性常微分方法动力系统的Ｆ     

网站用户登录信息挖掘特征规则

本文首先研究了基本的面向属性归纳，提出了从网站用户登录信息中挖掘用户特征规则的思路。问题从解决多属性归纳着手，特点是首先建立概念树，然后用条件属性组合与约束的方法进行挖掘。实验表明，本文设计的模型能客观地描述客户行为，为从Web信息挖掘客户特征规则提出了一条有效的途径。     

波纹壳的格林函数方法

应用轴对称旋转扁壳的基本方程,研究了在任意载荷作用下具有型面锥度的浅波纹壳的非线性弯曲问题·　采用格林函数方法,将扁壳的非线性微分方程组化为非线性积分方程组·　再使用展开法求出格林函数,即将格林函数展成特征函数的级数形式,积分方程就成为具有退化核的形式,从而容易得到非线性代数方程组·　应用牛顿法求解非线性代数方程组时,为了保证迭代的收敛性,选取位移作为控制参数,逐步增加位移,求得相应的载荷·　在算例中,研究了具有球面度的浅波纹壳的弹性特征·　结果表明,由于型面锥度的引入,特征曲线发生显著变化,随着荷载的增加,将出现类似扁球壳的总体失稳现象·　本文的解答符合实验结果·     

数量特征敏感性问题调查的两个随机化回答模型

研究数量特征敏感性问题的抽样调查,设计了基于离散均匀分布和均匀分布的两个随机化回答模型     

不动点集为RP(4)∪ P(4,2n-1)的对合

设(M,T)是一个光滑闭流形上的对合,不动点集为F=RP(4)UP(4,2n-1),则它的每一个对合(M,T)必协边(RP(4)×RP(4),twist)和(P(4,2n),T')之一.     

ALGEBROIDAL FUNCTION AND ITS DERIVED FUNCTION IN UNIT CIRCULAR DISC

In this article,the authors define the derived function of an algeboidal function in the unit disc,prove it is an algabriodal function,and study the order of algebroidal function and that of its derived function in unit circular disc.     

三次矩阵方程的解的判定

给定A∈Mn(F),g(x)=x3+ax2+bx+c∈F[x],本文讨论矩阵方程g(X)=A的解的存在性问题.在Li′s研究的基础上,当f(x)=p1(x)p2(x)…ps(x)时,我们给出g(X)=A有解的充要条件为对每一个pi(x),pi(g(x))在F[x]中存在ni次因式,ni=degpi(x).     

线性常系数非齐次微分方程的特解公式

用初等方法得到n阶线性常系数非齐次方程y(n)+a1y(n-1)+…+any=Pm(x)eλx特解y*的求解公式,使求y*的计算比较简单.