推荐系统综述recommder

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பைடு நூலகம்
Matrix factorization
LFM(Latent factor model)
Matrix factorization
Probabilistic MF
Salakhutdinov, Ruslan, and Andriy Mnih. "Probabilistic matrix factorization."NIPS. Vol. 20. 2011.
collaborative filtering
The Long Tail
User-based CF
Konstan, Joseph A., et al. "GroupLens: applying collaborative filtering to Usenet news." Communications of the ACM 40.3 (1997): 77-87
Probabilistic MF
Probabilistic MF
Automatic Complexity Control
Constrained PMF
Experimental Results
Experimental Results
Problem
评价一个推荐系统标准
算法效率、可解释性
简单的算法+海量数据应该是能符合实际生产环境
Thanks !
Cosine Similarity
Jaccard Coefficient
Neighborhoods
K-neighborhoods or Threshold-based neighborhoods
Similarity Computing
Similarity Computing
Item-based CF
User-based CF
Grouplens
—The rating servers predict scores based on the heuristic that people who agreed in the past will probably agree again.
—Basic idea: recommend items similar to users favorite items. —GroupLens Architecture Overview —A Dynamic and Fast-Paced Information System —Ratings Sparsity —Performance Challenges
Content-based
example (movie)
Item Profiles - its genre - the participating actors - Its box office popularity - so forth User Profiles - movies and score list
Matrix factorization
Yehuda, Robert Bell, and Chris Volinsky. "Matrix factorization techniques for recommender systems." Computer 42.8 (2009): 30-37.
Matrix factorization
A basic matrix factorization model
Matrix factorization
ˆ R P QT = R
Matrix factorization
K ˆij piT q j k r 1 pik qkj
2 K 2 ˆij ) 2 (rij k eij (rij r p q ) 1 ik kj
history




Content Filtering [Before 1992] Grouplens [1994] —Frist recommender system using rating data Movielens[1997] —Frist movie recommender system —Provide well-known dataset for researchers Amazon —proposed item-based collaborative filtering (Patent is filed in 1998 and issued in 2001) Netflix Prize[2006] —Latent Factor Model(SVD,RSVD,NSVD,SVD++) —Yehuda Koren’s team get prize
Recommender Systems Introduction
Cheng Shi
20.Dec.2016
Outline
Backgrounds
& history
Algorithms
Content-based Recommendation Collaborative Filtering-based Recommendation • User-based Recommendation • Item-based Recommendation • Model-based Recommendation Problem

Backgrounds
Information overload is one of the most critical problems, and personalized recommendation system is a powerful tool to solve this problem.
Matrix factorization
Matrix factorization
Biases:
Temporal dynamics: Confidence levels:
Browsing Additional input sources : history,gender,age group
Zip code,income level
Linden, Greg, Brent Smith, and Jeremy York. "Amazon. com recommendations: Item-to-item collaborative filtering." IEEE Internet computing 7.1 (2003): 76-80.
User-based CF
Establishment of user model
Similarity Computing
Find similar users set
Euclidean Distance Similarity
Similarity Computing
Pearson Correlation Similarity
Item-based CF
Amazon.com
-Few details
-basic idea
-Scalability
Item-based CF
M users, N items
O( N M )
2
O( NM )
Item-based CF sample
Scalability
Amazon.com has more than 29 million customers and several million catalog items. For large retailers like Amazon.com, a good recommendation algorithm is scalable over very large customer bases and product catalogs, requires only subsecond processing time to generate online recommendations.
2006年,NETFLIX宣布,设立一项大赛,公 开征集电影推荐系统的最佳电脑算法,第一 个能把现有推荐系统的准确率提高10%的参赛 者将获得一百万美元的奖金。2009 年 9 月 21 日,来自全世界 186 个国家的四万多个 参赛团队经过近三年的较量,终于有了结果。 一个由工程师和统计学家组成的七人团队夺 得了大奖,拿到了那张百万美元的超大支票。
A Comparison
Scalability Diversity&
Precision
Netflix Prize
Netflix是一家美国在线视频网站,公司一 开始的主要业务是提供DVD和Blu-ray光盘的出 租服务。现在的主要业务是原创内容的网络流 媒体服务。2013年凭借高端自制美剧《纸牌屋》 和随后的多部剧集的超高质量引起全球瞩目。
history
After 2006 —Interpretability of the recommendation results —Join the sentiment analysis to the Matrix Factorization
—Recommender Systems with Deep Learning
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