7,037 research outputs found
Modeling Time-Series and Spatial Data for Recommendations and Other Applications
With the research directions described in this thesis, we seek to address the
critical challenges in designing recommender systems that can understand the
dynamics of continuous-time event sequences. We follow a ground-up approach,
i.e., first, we address the problems that may arise due to the poor quality of
CTES data being fed into a recommender system. Later, we handle the task of
designing accurate recommender systems. To improve the quality of the CTES
data, we address a fundamental problem of overcoming missing events in temporal
sequences. Moreover, to provide accurate sequence modeling frameworks, we
design solutions for points-of-interest recommendation, i.e., models that can
handle spatial mobility data of users to various POI check-ins and recommend
candidate locations for the next check-in. Lastly, we highlight that the
capabilities of the proposed models can have applications beyond recommender
systems, and we extend their abilities to design solutions for large-scale CTES
retrieval and human activity prediction. A significant part of this thesis uses
the idea of modeling the underlying distribution of CTES via neural marked
temporal point processes (MTPP). Traditional MTPP models are stochastic
processes that utilize a fixed formulation to capture the generative mechanism
of a sequence of discrete events localized in continuous time. In contrast,
neural MTPP combine the underlying ideas from the point process literature with
modern deep learning architectures. The ability of deep-learning models as
accurate function approximators has led to a significant gain in the predictive
prowess of neural MTPP models. In this thesis, we utilize and present several
neural network-based enhancements for the current MTPP frameworks for the
aforementioned real-world applications.Comment: Ph.D. Thesis (2022
RippleNet: Propagating User Preferences on the Knowledge Graph for Recommender Systems
To address the sparsity and cold start problem of collaborative filtering,
researchers usually make use of side information, such as social networks or
item attributes, to improve recommendation performance. This paper considers
the knowledge graph as the source of side information. To address the
limitations of existing embedding-based and path-based methods for
knowledge-graph-aware recommendation, we propose Ripple Network, an end-to-end
framework that naturally incorporates the knowledge graph into recommender
systems. Similar to actual ripples propagating on the surface of water, Ripple
Network stimulates the propagation of user preferences over the set of
knowledge entities by automatically and iteratively extending a user's
potential interests along links in the knowledge graph. The multiple "ripples"
activated by a user's historically clicked items are thus superposed to form
the preference distribution of the user with respect to a candidate item, which
could be used for predicting the final clicking probability. Through extensive
experiments on real-world datasets, we demonstrate that Ripple Network achieves
substantial gains in a variety of scenarios, including movie, book and news
recommendation, over several state-of-the-art baselines.Comment: CIKM 201
- …