Partner selection is an important problem in agile manufacturing and supply chain management. We try to solve it by gene algorithm with embedded fuzzy rules. 1) Problem description Suppose a company won a bid of a big project, which consists of $n$ sub projects. The company can not finish the projec […]
081 月
前端开发经验总结
归类于未分类 2 条评论
无论是偏重于页面制作(即切图也)，还是偏重于页面动态效果开发，扎实的CSS知识是前端开发人员必备的。由于各种浏览器间存在兼容性问题(体现在CSS写法，脚本等方面)，前端开发人员必须清楚对于各种浏览器兼容问题的处理方法。只有基础扎实了，面对复杂的需求，深入的应用前端技术才能有所依赖，解决问题也会快速许多。 浏览器将网页呈现给用户，用户看到的是经过渲染的，添加了各种效果的页面，在这个页面后面，开发人员主要通过html，css及js(本文默认脚本为js)实现了浏览器展现页面所需要的大多数内容(图片等资源归于UI)。html，css和js三者，是网页的结构，表现和行为三个方面。 html是页面的骨架， […]
051 月
线性回归模型简介
归类于IT 线性回归模型简介已关闭评论
Suppose $Y$ is a response variable, $X_p$ is a $p$-dimension covariates, $\epsilon$ is random error. We say $Y$ linearly dependents $X_p$ if $$Y=X_p^T\beta+\epsilon,(*)$$ here $A^T$ is the transpose of matrix $A$. With model(*), we have some tasks to finish: 1) Does model(*) correctly describe the d […]
051 月
蚁群算法
归类于未分类 3 条评论
Italy scholar Dorigo M. et al. proposed Ant colony algorithm at European Conference on Artificial Life, ECAL) in 1991. 1) Basic Ideas Ant Colony Algorithm(ACA) simulates how ants find the food. Why ants can find the shortest way from their nest to the food? Pheromone is the key. Pheromone can be det […]
051 月
遗传算法
Gene Algorithm(GA) is a very popular intelligent optimization algorithm. It was proposed by professor John H. Holland and his students of University Michigan at 1960s and 1970s. By evolution of populations, solutions represented by individuals promote the fitness to the environment. After enough gen […]
051 月
EM算法
归类于数学 EM算法已关闭评论
Suppose we have samples ${X_i,i=1,\cdots,n}$ from $p$-dimension normal distribution, and some observations have partial missing values. Without loss of generality, assume missing values occure at indexes $1,\cdots,d$, and $d < p$. Then how do we estimate the mean and variance of the underlying distr […]
051 月
非参数模型
归类于数学 非参数模型已关闭评论
What is a nonparametric model? Linear regression models has parameters, the coefficients of covariates, and possible an intercept. A nonparametric model looks like \[Y=g(T)+\epsilon,(*)\] here $T$ is a univariate, $Y$ is the response, $\epsilon$ is the error. Model(*) is said to be infinite-dimensio […]
051 月
Euler常数γ的推广
Xiu-You Xu* Email:xiuyouxu#gmail.com abstract When $n\rightarrow\infty$, it is well known that $\sum\nolimits_{i=1}^n\frac{1}{i}\sim{\ln{n}+\gamma}$, where $\gamma$ is Euler-Mascheroni Constant. We will talk about the coefficients of the function having $(-lnx)^m$ as $n$th-order derivative, and gene […]