Collaborative Filtering via Group-Structured Dictionary Learning
  Structured sparse coding and the related structured dictionary learning problems are novel research areas in machine learning. In this paper we present a new application of structured dictionary learning for collaborative filtering based recommender systems. Our extensive numerical experiments demonstrate that the presented technique outperforms its state-of-the-art competitors and has several advantages over approaches that do not put structured constraints on the dictionary elements. 
Zoltan Szabo, Barnabas Poczos, Andras Lorincz
math.OC cs.LG math.ST stat.ML stat.TH