Archives: 2020/7 | Tech Blog

2020

07

28

jvm

JVM体系架构java是跨平台的语言，JVM是跨语言的平台（Kotlin,Scala, Jython, JRuby, JavaScript…)。JVM不关心运行在其内部的程序的编程语言，只关心字节码文件。特点：一次编译，到处运行自动

2020-07-28 Java

22

hands on: 16 nlp

Generate Text with Character RNNEncode every character as an integer. Encode the full text so each character is represen

2020-07-22 Deep Learning

DL

22

hands on: 08 dimension reduction

In some cases, reducing the dimensionality of the training data may filter out some noise and unnecessary details and th

2020-07-22 Deep Learning

DL

22

hands on: 09 unsupervised

ClusteringIdentify similar instances and assign them to clusters. Application customer segmentation Cluster customers b

2020-07-22 Deep Learning

DL

22

hands on: 14 cnn

Conv LayersIn turn, each neuron in the second conv layer is connected only to neurons located within a small rectangle i

2020-07-22 Deep Learning

DL

22

ml basic: 02 feature engineering

特征工程2.1 特征提取将原始数据转化为实向量之后，为了让模型更好地学习规律，对特征做进一步的变换。首先，要理解业务数据和业务逻辑。其次，要理解模型和算法，清楚模型需要什么样的输入才能有精确的结果。 2.1.1 探索性数据分析Explo

2020-07-22 Machine Learning

ML

21

hands on: 06 decision tree

Train and Visualize a Decision TreeTry to understand how it makes predictions. from sklearn.tree import DecisionTreeCla

2020-07-21 Deep Learning

DL

21

hands on: 05 svm

Linear SVM ClassificationSVM are sensitive to the feature scales. Soft Margin ClassificationIf we strictly impose that

2020-07-21 Deep Learning

DL

21

ml basic: 01 problem modeling

问题建模1.1 评估指标线下使用机器学习评估指标，线上使用的是业务指标。需要进行多轮模型迭代使两个指标变化趋势相同。 1.1.1 分类指标精确率和召回率用于二分类问题，结合混淆矩阵。精确率 P = $\frac{TP}{T

2020-07-21 Machine Learning

ML

21

tree

二叉树 Tree 先问清楚是不是二叉树？二叉搜索树？子节点到父节点的指针？大部分题目可以通过递归解决掌握四种遍历树的方法inorder, preorder, postorder, level order 配合遍历的顺序，有可

2020-07-21 algorithm

algorithm 算法 tree Trie Segment Tree BIT

21

greedy

贪心算法排序！如果是内置数据结构，直接使用自定义排序。排序之后考虑能否使用binary search。 Arrays.sort(arr, new Comparator<int[]>() { public int compa

2020-07-21 algorithm

algorithm 算法 greedy

21

list

链表概况链表存储空间不一定连续，是临时分配的，所以不能像数组一样用索引提取元素。大量链表问题可以使用额外数据结构简化。但是最优解一般不使用额外数据结构。解题要点单向/双向？有环/无环？翻转链表、交换两个节点是基础头节点有可能发生变

2020-07-21 algorithm

algorithm 算法链表