基于拟合函数的艾滋病治疗模型的评价

艾滋病的治疗方法很多,为了能够准确、及时、有效地治疗艾滋病,需要从众多的治疗方案中找到合适的一种,为此利用拟合函数、边际疗效和性价比建立了一个评价艾滋病疗法优劣的数学模型.并利用计算机中的数据库知识对该数学模型进行了分析,使它更接近现实生活中艾滋病的治疗.     

Non-equal-interval direct optimizing Verhulst model that x(n) be taken as initial value and its application

To overcome the deficiencies of the existing Verhulst GM(1,1) model, based on the existing grey theory, a non-equal-interval direct optimum Verhulst GM(1,1) model is built which chooses a modified n-th component x(n) of X(0) as the starting condition of the grey differential model. It optimizes a modified β value and the background value, and takes two times fitting optimization. The new model extends equal intervals to non-equal-intervals and is suitable for general data modelling and estimating parameters...     

汽车发动机性能仿真模型研究

将发动机速度、负荷和万有特性离散化为矩阵形式,采用曲线、曲面拟合、神经网络方法进行数学建模,建立了汽车发动机仿真数学模型,开发了计算仿真程序。对发动机外特性进行拟合,拟合阶次越高,结果越精确,采取5阶拟合即可以真实反映发动机的外特性;对发动机万有特性与负荷特性进行拟合,拟合度为99．85％,可见试验数据模型化后的结果是可以接受的．,建立数学模型具有很高的模拟精度,能精确地反映出发动机的特性。     

State disinvestment,technologies of choice and ‘fitting in’: neoliberal transformations in US public education

Given state cuts to US public education, overcrowding and underfunding in urban district schools continue to grow. Yet, how parents understand the role of state disinvestment on underfunded and overcrowded public schools remains relatively unexamined. Drawing from an ethnographic study of school choice in Arizona, I explore how a group of white parents from diverse income and educational levels, who exited their child from a district school to enroll in a charter school, articulated state disinvestment in their everyday lives. Findings show that parents blamed local schools for what were largely the effects of state disinvestment. In particular, parents connected underfunding and overcrowding with a lack of district responsiveness to individual concerns to express the view that dire conditions were a personal and not a collective problem. Concurrent with the view that they were ‘were forced to choose’ a charter school due to a lack of district responsiveness, parents developed the belief that choice makes education more equal, especially for students who don’t ‘fit in’ to the district school. In total, findings highlight how technologies of choice enter into local cultural and material struggles to transform the relationship between parents and schools from a social to an economic one.     

甲醇摩托发动机高能点火互感电路过渡过程研究及仿真分析

提出一种研究高能点火互感电路过渡过程的新方法。通过对磁介质磁化曲线采用数理统计方法拟合，找出拟合函数，然后运用四阶龙格－库塔法求解微分方程。文中求出初级电流瞬态解，同时给出PSPICE软件仿真结果。     

聚合物广角X射线衍射图谱分峰的改进

首先采用高精度的Lagrange多项式插值对聚合物无定形样品广角X衍射(WAXD)谱图的峰形进行拟合,得到的该聚合物无定形峰的函数,然后将该函数与Gauss-Cauchy函数结合,对该聚合物的WXAD图谱进行非线性最小二乘法分峰拟合,得到了较理想的结果,并讨论了分峰过程中初值的稳定性。     

基于正切网络法测量低耗介质相对介电常数

基于正切网络法,将填充低耗介质的波导段等效为正切网络,利用曲线拟合法求得网络参数,从而反演出相对介电常数。借助于微波CAT(Computer Aided Test)系统,对实际低耗电介质材料进行了测试,测量结果与标称值吻合较好。     

A356合金疲劳数据的数理统计分析

研究了不同加钛方式和钛含量对A356合金低周疲劳性能的影响,并重点对实验数据进行了数理统计分析,拟合了四种合金的Manson-Confin方程,分析了实验数据的统计可靠性与显著性。结果表明,A356合金低周疲劳寿命对加钛方式不敏感,其疲劳寿命仅受合金中Ti含量影响。无论电解加钛合金还是熔配加钛合金,Ti含量为0．1％的合金较0．14％的合金具有更优异的低周疲劳性能。     

打好城市规划的四张牌

在全国市政建设中,理性进行城市规划迫在眉睫。在保持城市普遍功能的同时打造城市名牌是城市建设规划的重点。有选择的打好城市宜居牌、历史人文牌、低碳环保牌、公众参与牌是体现城市魅力的重要手段。     

基于Web的三维试衣系统人体模型技术研究

服装电子商务平台的三维化和信息化是未来服装行业的发展趋势。通过Web维建模技术可实现电子商务平台中三维试衣系统的人体模型编码和设计。X3D虚拟人动画节点设计执行了H-Aaim标准,通过对不同节点定义以及代码编程,来完成人体模型的建立。采用X3D的虚拟现实技术,能满足虚拟现实的交互性和沉浸感的要求,弥补了服装电子商务不能进行试穿的不足。