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README.md

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 * [Research Frontier of Real-Time Bidding based Display Advertising](https://github.com/wzhe06/Ad-papers/blob/master/Bidding%20Strategy/Research%20Frontier%20of%20Real-Time%20Bidding%20based%20Display%20Advertising.pdf)
 ### Budget Control
 广告系统中Pacing，预算控制，以及怎么把预算控制与其他模块相结合的问题
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+* [Budget Pacing for Targeted Online Advertisements at LinkedIn](https://github.com/wzhe06/Ad-papers/blob/master/Budget%20Control/Budget%20Pacing%20for%20Targeted%20Online%20Advertisements%20at%20LinkedIn.pdf)
+* [PID控制原理与控制算法](https://github.com/wzhe06/Ad-papers/blob/master/Budget%20Control/PID%E6%8E%A7%E5%88%B6%E5%8E%9F%E7%90%86%E4%B8%8E%E6%8E%A7%E5%88%B6%E7%AE%97%E6%B3%95.doc)
+* [PID控制经典培训教程](https://github.com/wzhe06/Ad-papers/blob/master/Budget%20Control/PID%E6%8E%A7%E5%88%B6%E7%BB%8F%E5%85%B8%E5%9F%B9%E8%AE%AD%E6%95%99%E7%A8%8B.pdf)
+* [Real Time Bid Optimization with Smooth Budget Delivery in Online Advertising](https://github.com/wzhe06/Ad-papers/blob/master/Budget%20Control/Real%20Time%20Bid%20Optimization%20with%20Smooth%20Budget%20Delivery%20in%20Online%20Advertising.pdf)
+* [Smart Pacing for Effective Online Ad Campaign Optimization](https://github.com/wzhe06/Ad-papers/blob/master/Budget%20Control/Smart%20Pacing%20for%20Effective%20Online%20Ad%20Campaign%20Optimization.pdf)
 ### CTR Prediction
 CTR预估模型相关问题
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 ### Computational Advertising Architect
 广告系统的架构问题
 ### Computer Vision