優萌初華

Chapter 1 - Introduction to Software Engineering. # Quiz What are the two fundamental types of software product? Generic software Expensive Software Customized Software Complex Software There are no universal notations, methods, or techniques for software engineering because different types of...

# Unsupervised learning 无监督学习 Unsupervised learning is the machine learning task of inferring a function to describe hidden structure from unlabeled data. 无监督学习是从未标记的数据中推断出描述隐藏结构的函数的机器学习任务。 Since the examples given to the learner are unlabeled, there is no error or reward signal to evaluate a...

# Neural Networks # Artificial Neural Networks (ANN) Researchers tried to learn from the biological neuron systems and built the ANN 研究人员试图向生物神经元系统学习，并建立了 ANN There are many neuron units in ANN ANN 中有许多神经元单位 They are connected within a structure 他们是连接在一个结构 They work as threshold switching...

# Decision Trees 决策树 「机器学习实战」摘录 - 决策树 k -...

# K-Nearest Neighbor (KNN) Classifier k - 近邻算法 「机器学习实战」摘录 - k-近邻算法 k - 近邻算法采用测量不同特征值之间的距离方法进行分类。 优点：精度高、对异常值不敏感、无数据输入假定。 缺点：计算复杂度高、空间复杂度高。 适用数据范围：数值型和标称型。 Problem: Identify which animal the given object it is 问题：识别给定对象是哪种动物 Features: weights, age, gender, stripes, size,...

Emphasis: understand the techniques What it is What problems it can solve In which situations we should use them Any limitations or requirements to use them How to evaluate them # Supervised v.s. Unsupervised Learning 监督学习和无监督学习 # Supervised Learning 监督学习 infer a (predictive) function from data...

# Getting to Know Data # Types of the Data 「机器学习实战」摘录 - 两种类型的目标变量 监督学习一般使用两种类型的目标变量：数值型和标称型。 数值型目标变量则可以从无限的数值集合中取值，如 0.100、42.001、1000.743 等。数值型目标变量主要用于回归分析。 标称型目标变量的结果只在有限目标集中取值，如真与假、动物分类集合 {爬行类、鱼类、哺乳类、两栖类}。 # Qualitative (Categorical/Nominal) 定性（标称型） Nominal = Values are strings 值是字符串 Special...

# Babel Babel is used to convert JSX to plain JavaScript React calls. Babel 用于将 JSX 转换为普通的 JavaScript 反应调用。 Babel can also compile our ES6+ to ES5 还可以将 ES6 编译成 ES5 Babel can be directly used in the browser for development purposes 出于开发目的，可以在浏览器中直接使用 Babel <script...

# Outline Continuous and Continuous Variables 连续变量和连续变量 Pearson's correlation coefficient 皮尔逊相关系数 Categorical and Continuous Variables 分类变量和连续变量 ANOVA Test 方差分析检验 Categorical and Categorical Variables 分类变量和分类变量 Chi-squared Test 卡方检验 # Correlation between Numerical Variables 数值变量之间的相关性 To...

# Part I: Tests for a cybersecurity data set Let's revisit cybersecurity breach report data downloaded 2015-02-26 from the US Health and Human Services. From the Office for Civil Rights of the U.S. Department of Health and Human Services, I obtained the following information: "As...