在仙侠剧中，有正魔之分，然何为正道，何为魔道，实属难辨。自称正道的人也许某一天会堕入魔道，被众人称为魔头的人，或许内心自始至终都充溢着正义感！所以说，没有绝对的黑，也没有绝对的白。话说回来，对于“异常”这个词，每个人的心里大概都有一个衡量标准，扩展起来的确很广（如异常点、异常交易、异常行为、异常用户、异常事故等等），那么究竟何为异常呢？异常是相对于其他观测数据而言有明显偏离的，以至于怀疑它与正常点不属于同一个数据分布。异常检测是一种用于识别不符合预期行为的异常模式的技术，又称之为异常值检测。在商业中也有许多应用，如网络入侵检测（识别可能发出黑客攻击的网络流量中的特殊模式）、系统健康性监测、信用卡交易欺诈检测、设备故障检测、风险识别等。这里，将异常分为三种： 数据点异常：如果样本点与其他数据相距太远，则单个数据实例是异常的。业务用例：根据“支出金额”检测信用卡欺诈。 上下文异常：在时间序列数据中的异常行为。业务用例：旅游购物期间信用卡的花费比平时高出好多倍属于正常情况，但如果是被盗刷卡，则属于异常。 集合异常：单个数据难以区分，只能根据一组数据来确定行为是否异常。业务用例：蚂蚁搬家式的拷贝文件，这种异常通常属于潜在的网络攻击行为。

In the age of specialization for electronics engineers, it becomes very difficult to maintain a level of competence within a broad range of electronics fields. Nonetheless, many engineers will be assigned design projects outside their primary field of expertise, among which are switching power supplies. This is done priniarily because the engineer has a unique ability to learn technical subjects relatively quickly. Unfortunately, the literature available today on the subject of switching power supplies tries to convey an understanding through lengthy derivations of applied mathematics. This does not work since only an intuitive sense of the subject matter creates an understanding of the fundamental re 1 at i on sh ips.

Optimizing Java_Practical Techniques for Improving JVM Application Performance(2018.05).A4.pdf 预览文字版 Currently, no books exist that focus on the practicalities of Java application performance tuning, as opposed to the theory and internals of Java virtual machines. This practical guide is the "missing link" that aims to move Java performance tuning from the realm of guesswork and folklore to an experimental science.

Practical statistical network analysis(with R and igraph) 洛桑大学R语言中igraph讲义，适合快速入门

Verilog Quickstart--Practical Guide to Simulation & Synthesis in Verilog

一款可以将任何软件都卸载干净的绿色小工具，非常实用，无需安装，window内置都可以卸载！

Practical Guide for Oracle SQL,T-SQL and MySQL 英文无水印原版pdf pdf所有页面使用FoxitReader、PDF-XChangeViewer、SumatraPDF和Firefox测试都可以打开 本资源转载自网络，如有侵权，请联系上传者或csdn删除 查看此书详细信息请在美国亚马逊官网搜索此书

Knowing how a camera works does not make you a great photographer. Knowing what cryptographic designs are and how existing cryptographic protocols work does not give you proficiency in using cryptography. You must learn to think like a cryptographer. That is what this book will teach you. Dive deeply into specific, concrete cryptographic protocols and learn why certain decisions were made. Recognize the challenges and how to overcome them. With this book, which is suitable for both classroom and self-study, you will learn to use cryptography effectively in real-world systems.

Vertex and Fragment Shaders for Game Developers This book is intended to be the gentlest introduction possible to the theory and practice of writing shaders for video games.

A Practical Guide for Designing, Synthesizing, and Simulating ASICs and FPGAs using VHDL or Verilog FPGA和ASIC开发非常有用的一本书，书中以实例讲解了许多开发思想和开发技巧，对提高逻辑设计的工作频率及效率有非常好的指导意义