葡萄酒的评价模型

根据给出的数据,采用秩和检验法、T检验法和区分度标准,分析两组评酒员的结果差异和可信度。以酿酒葡萄的理化指标、葡萄酒的质量为参数,建立聚类分析模型,对酿酒葡萄进行分类定级;通过对葡萄和葡萄酒理化指标的相关性分析筛选变量,然后在二者之间进行多元回归拟合;运用同样的方法,得到用葡萄和葡萄酒的理化指标对葡萄酒质量的评价公式,并进行模型检验。     

利用折射表征盐水浓度

光从一种介质进入到另外一种介质,光的传播方向会发生改变。每一种物质都有其自身的光学特性,其物质本身特性决定了光从另外一种介质进入介质本身的折射情况,对于不同浓度的食盐水对应了相应不同的密度,同时也就对应了相应不同的折射率。本文所设计的装置可直接读出食盐水浓度。     

On Latent Change Model Choice in Longitudinal Studies

An interval estimation procedure for proportion of explained observed variance in latent curve analysis is discussed, which can be used as an aid in the process of choosing between linear and nonlinear models. The method allows obtaining confidence intervals for the R ² indexes associated with repeatedly followed measures in longitudinal studies. In addition to facilitating evaluation of local model fit, the approach is helpful for purposes of differentiating between plausible models stipulating different patterns of change over time, and in particular in empirical situations characterized by large samples and high statistical power. The procedure is also applicable in cross-sectional studies, as well as with general structural equation models. The method is illustrated using data from a nationally representative study of older adults.     

关于线性代数课程教学的探讨

在准备线性代数课程教学的过程中,应以其知识体系为依据,以提高教育教学质量为目的,对课程内容进行梳理与分析,确定课程内容间的关系,找出授课过程中的重点和难点.在教学过程中注意对相关的内容进行取舍,对学生进行快速计算训练.     

脑卒中发病环境因素分析及干预的数学模型

依据2012年全国大学生数学建模竞赛C题所给的脑卒中发病病例信息,运用Excel软件筛选功能,将数据进行分类整理及统计规律分析,发现脑卒中发病人群易集中于老年人,男性得病比例高于女性,春季为此病发作高峰期,农民患此病人数最多.在合理假设的基础上,运用MATLAB软件进行多元线性回归分析,建立了脑卒中发病与环境因素关系的数学模型.通过数学模型及脑卒中高危人群的重要特征和关键指标,指出脑卒中发病的规律,对脑卒中高危人群进行预警和干预.     

关于矩阵方程求解的讨论

着重讨论了形如XA=B及AXC=B的矩阵方程的求解原理及几种解法,简要分析了各种方法的原理及联系,并提出了对教材处理和教学的建议.     

一类EV模型中参数σ~2的加权M估计的渐近正态性

考虑变系数多维线性结构关系EV模型y=xTβ(t),Y=y+ε,X=x+u,利用文[4]构造的参数β(t)在t=t0处的参数β(t0)的估计量βn(t0)构造参数σ2的估计量σn2,并证明它具有渐近正态性.     

Effect of the scale of quantitative trait data on the representativeness of a cotton germplasm sub-core collection

A cotton germplasm collection with data for 20 quantitative traits was used to investigate the effect of the scale of quantitative trait data on the representativeness of plant sub-core collections.The relationship between the representativeness of a sub-core collection and two influencing factors,the number of traits and the sampling percentage,was studied.A mixed linear model approach was used to eliminate environmental errors and predict genotypic values of accessions.Sub-core collections were constructed using a least distance stepwise sampling(LDSS) method combining standardized Euclidean distance and an unweighted pair-group method with arithmetic means(UPGMA) cluster method.The mean difference percentage(MD),variance difference percentage(VD),coincidence rate of range(CR),and variable rate of coefficient of variation(VR) served as evaluation parameters.Monte Carlo simulation was conducted to study the relationship among the number of traits,the sampling percentage,and the four evaluation parameters.The results showed that the representativeness of a sub-core collection was affected greatly by the number of traits and the sampling percentage,and that these two influencing factors were closely connected.Increasing the number of traits improved the representativeness of a sub-core collection when the data of genotypic values were used.The change in the genetic diversity of sub-core collections with different sampling percentages showed a linear tendency when the number of traits was small,and a logarithmic tendency when the number of traits was large.However,the change in the genetic diversity of sub-core collections with different numbers of traits always showed a strong logarithmic tendency when the sampling percentage was changing.A CR threshold method based on Monte Carlo simulation is proposed to determine the rational number of traits for a relevant sampling percentage of a sub-core collection.     

基于CCD的高精度细丝直径在线检测技术研究

在现代工业生产中,人们通过在线检测的方法对细丝进行实时监测与控制,提高产品合格率以及效率,为人们带来方便,非接触式智能化仪器将逐步取代传统上的机械测量仪器。本文阐述了CCD成像法测量装置的基本原理,分析了光学系统各部分的形式,并采用远心光路成像,从而保证成像质量和测量精度。之后用阈值法提取被测工件的边缘信息,同时还给出了CCD成像法测量直径系统的MATLAB处理后的灰度图。     

基于最优成本估算的多产品供应链协调机制研究

针对手机市场中出现的间接广告现象,研究了多产品销售条件下,供应链新产品成本估算以及协调问题。建立了非对称信息下多产品的批发价与订货量的stackelberg博弈模型,给出了供应商和零售商在集中决策和分散决策下的博弈均衡。研究结论显示分散决策下零售商的订货量明显低于集中决策下的订货量,同时研究表明通过使用线性价格折扣共享契约(price-discount sharing)可以协调该供应链,并能任意地划分供应链的利润。