498 research outputs found
Topic-enhanced memory networks for personalised point-of-interest recommendation
Point-of-Interest (POI) recommender systems play a vital role in people's
lives by recommending unexplored POIs to users and have drawn extensive
attention from both academia and industry. Despite their value, however, they
still suffer from the challenges of capturing complicated user preferences and
fine-grained user-POI relationship for spatio-temporal sensitive POI
recommendation. Existing recommendation algorithms, including both shallow and
deep approaches, usually embed the visiting records of a user into a single
latent vector to model user preferences: this has limited power of
representation and interpretability. In this paper, we propose a novel
topic-enhanced memory network (TEMN), a deep architecture to integrate the
topic model and memory network capitalising on the strengths of both the global
structure of latent patterns and local neighbourhood-based features in a
nonlinear fashion. We further incorporate a geographical module to exploit
user-specific spatial preference and POI-specific spatial influence to enhance
recommendations. The proposed unified hybrid model is widely applicable to
various POI recommendation scenarios. Extensive experiments on real-world
WeChat datasets demonstrate its effectiveness (improvement ratio of 3.25% and
29.95% for context-aware and sequential recommendation, respectively). Also,
qualitative analysis of the attention weights and topic modeling provides
insight into the model's recommendation process and results.China Scholarship Council and Cambridge Trus
A Diffusion model for POI recommendation
Next Point-of-Interest (POI) recommendation is a critical task in
location-based services that aim to provide personalized suggestions for the
user's next destination. Previous works on POI recommendation have laid focused
on modeling the user's spatial preference. However, existing works that
leverage spatial information are only based on the aggregation of users'
previous visited positions, which discourages the model from recommending POIs
in novel areas. This trait of position-based methods will harm the model's
performance in many situations. Additionally, incorporating sequential
information into the user's spatial preference remains a challenge. In this
paper, we propose Diff-POI: a Diffusion-based model that samples the user's
spatial preference for the next POI recommendation. Inspired by the wide
application of diffusion algorithm in sampling from distributions, Diff-POI
encodes the user's visiting sequence and spatial character with two
tailor-designed graph encoding modules, followed by a diffusion-based sampling
strategy to explore the user's spatial visiting trends. We leverage the
diffusion process and its reversed form to sample from the posterior
distribution and optimized the corresponding score function. We design a joint
training and inference framework to optimize and evaluate the proposed
Diff-POI. Extensive experiments on four real-world POI recommendation datasets
demonstrate the superiority of our Diff-POI over state-of-the-art baseline
methods. Further ablation and parameter studies on Diff-POI reveal the
functionality and effectiveness of the proposed diffusion-based sampling
strategy for addressing the limitations of existing methods
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