1,756 research outputs found
Mixed Information Flow for Cross-domain Sequential Recommendations
Cross-domain sequential recommendation is the task of predict the next item
that the user is most likely to interact with based on past sequential behavior
from multiple domains. One of the key challenges in cross-domain sequential
recommendation is to grasp and transfer the flow of information from multiple
domains so as to promote recommendations in all domains. Previous studies have
investigated the flow of behavioral information by exploring the connection
between items from different domains. The flow of knowledge (i.e., the
connection between knowledge from different domains) has so far been neglected.
In this paper, we propose a mixed information flow network for cross-domain
sequential recommendation to consider both the flow of behavioral information
and the flow of knowledge by incorporating a behavior transfer unit and a
knowledge transfer unit. The proposed mixed information flow network is able to
decide when cross-domain information should be used and, if so, which
cross-domain information should be used to enrich the sequence representation
according to users' current preferences. Extensive experiments conducted on
four e-commerce datasets demonstrate that mixed information flow network is
able to further improve recommendation performance in different domains by
modeling mixed information flow.Comment: 26 pages, 6 figures, TKDD journal, 7 co-author
A Survey of Knowledge Graph Reasoning on Graph Types: Static, Dynamic, and Multimodal
Knowledge graph reasoning (KGR), aiming to deduce new facts from existing
facts based on mined logic rules underlying knowledge graphs (KGs), has become
a fast-growing research direction. It has been proven to significantly benefit
the usage of KGs in many AI applications, such as question answering,
recommendation systems, and etc. According to the graph types, existing KGR
models can be roughly divided into three categories, i.e., static models,
temporal models, and multi-modal models. Early works in this domain mainly
focus on static KGR, and recent works try to leverage the temporal and
multi-modal information, which are more practical and closer to real-world.
However, no survey papers and open-source repositories comprehensively
summarize and discuss models in this important direction. To fill the gap, we
conduct a first survey for knowledge graph reasoning tracing from static to
temporal and then to multi-modal KGs. Concretely, the models are reviewed based
on bi-level taxonomy, i.e., top-level (graph types) and base-level (techniques
and scenarios). Besides, the performances, as well as datasets, are summarized
and presented. Moreover, we point out the challenges and potential
opportunities to enlighten the readers. The corresponding open-source
repository is shared on GitHub
https://github.com/LIANGKE23/Awesome-Knowledge-Graph-Reasoning.Comment: This work has been submitted to the IEEE for possible publication.
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STAR:Spatio-temporal taxonomy-aware tag recommendation for citizen complaints
In modern cities, complaining has become an important way for citizens to report emerging urban issues to governments for quick response. For ease of retrieval and handling, government officials usually organize citizen complaints by manually assigning tags to them, which is inefficient and cannot always guarantee the quality of assigned tags. This work attempts to solve this problem by recommending tags for citizen complaints. Although there exist many studies on tag recommendation for textual content, few of them consider two characteristics of citizen complaints, i.e., the spatio-temporal correlations and the taxonomy of candidate tags. In this paper, we propose a novel Spatio-Temporal Taxonomy-Aware Recommendation model (STAR), to recommend tags for citizen complaints by jointly incorporating spatio-temporal information of complaints and the taxonomy of candidate tags. Specifically, STAR first exploits two parallel channels to learn representations for textual and spatio-temporal information. To effectively leverage the taxonomy of tags, we design chained neural networks that gradually refine the representations and perform hierarchical recommendation under a novel taxonomy constraint. A fusion module is further proposed to adaptively integrate contributions of textual and spatio-temporal information in a tag-specific manner. We conduct extensive experiments on a real-world dataset and demonstrate that STAR significantly performs better than state-of-the-art methods. The effectiveness of key components in our model is also verified through ablation studies
Empowering recommender systems using automatically generated Knowledge Graphs and Reinforcement Learning
Personalized recommendations have a growing importance in direct marketing,
which motivates research to enhance customer experiences by knowledge graph
(KG) applications. For example, in financial services, companies may benefit
from providing relevant financial articles to their customers to cultivate
relationships, foster client engagement and promote informed financial
decisions. While several approaches center on KG-based recommender systems for
improved content, in this study we focus on interpretable KG-based recommender
systems for decision making.To this end, we present two knowledge graph-based
approaches for personalized article recommendations for a set of customers of a
large multinational financial services company. The first approach employs
Reinforcement Learning and the second approach uses the XGBoost algorithm for
recommending articles to the customers. Both approaches make use of a KG
generated from both structured (tabular data) and unstructured data (a large
body of text data).Using the Reinforcement Learning-based recommender system we
could leverage the graph traversal path leading to the recommendation as a way
to generate interpretations (Path Directed Reasoning (PDR)). In the
XGBoost-based approach, one can also provide explainable results using post-hoc
methods such as SHAP (SHapley Additive exPlanations) and ELI5 (Explain Like I
am Five).Importantly, our approach offers explainable results, promoting better
decision-making. This study underscores the potential of combining advanced
machine learning techniques with KG-driven insights to bolster experience in
customer relationship management.Comment: Accepted at KDD (OARS) 2023 [https://oars-workshop.github.io/
Sequential Recommendation with Self-Attentive Multi-Adversarial Network
Recently, deep learning has made significant progress in the task of
sequential recommendation. Existing neural sequential recommenders typically
adopt a generative way trained with Maximum Likelihood Estimation (MLE). When
context information (called factor) is involved, it is difficult to analyze
when and how each individual factor would affect the final recommendation
performance. For this purpose, we take a new perspective and introduce
adversarial learning to sequential recommendation. In this paper, we present a
Multi-Factor Generative Adversarial Network (MFGAN) for explicitly modeling the
effect of context information on sequential recommendation. Specifically, our
proposed MFGAN has two kinds of modules: a Transformer-based generator taking
user behavior sequences as input to recommend the possible next items, and
multiple factor-specific discriminators to evaluate the generated sub-sequence
from the perspectives of different factors. To learn the parameters, we adopt
the classic policy gradient method, and utilize the reward signal of
discriminators for guiding the learning of the generator. Our framework is
flexible to incorporate multiple kinds of factor information, and is able to
trace how each factor contributes to the recommendation decision over time.
Extensive experiments conducted on three real-world datasets demonstrate the
superiority of our proposed model over the state-of-the-art methods, in terms
of effectiveness and interpretability
A Survey on Knowledge Graphs: Representation, Acquisition and Applications
Human knowledge provides a formal understanding of the world. Knowledge
graphs that represent structural relations between entities have become an
increasingly popular research direction towards cognition and human-level
intelligence. In this survey, we provide a comprehensive review of knowledge
graph covering overall research topics about 1) knowledge graph representation
learning, 2) knowledge acquisition and completion, 3) temporal knowledge graph,
and 4) knowledge-aware applications, and summarize recent breakthroughs and
perspective directions to facilitate future research. We propose a full-view
categorization and new taxonomies on these topics. Knowledge graph embedding is
organized from four aspects of representation space, scoring function, encoding
models, and auxiliary information. For knowledge acquisition, especially
knowledge graph completion, embedding methods, path inference, and logical rule
reasoning, are reviewed. We further explore several emerging topics, including
meta relational learning, commonsense reasoning, and temporal knowledge graphs.
To facilitate future research on knowledge graphs, we also provide a curated
collection of datasets and open-source libraries on different tasks. In the
end, we have a thorough outlook on several promising research directions
Recommending on graphs: a comprehensive review from a data perspective
Recent advances in graph-based learning approaches have demonstrated their
effectiveness in modelling users' preferences and items' characteristics for
Recommender Systems (RSS). Most of the data in RSS can be organized into graphs
where various objects (e.g., users, items, and attributes) are explicitly or
implicitly connected and influence each other via various relations. Such a
graph-based organization brings benefits to exploiting potential properties in
graph learning (e.g., random walk and network embedding) techniques to enrich
the representations of the user and item nodes, which is an essential factor
for successful recommendations. In this paper, we provide a comprehensive
survey of Graph Learning-based Recommender Systems (GLRSs). Specifically, we
start from a data-driven perspective to systematically categorize various
graphs in GLRSs and analyze their characteristics. Then, we discuss the
state-of-the-art frameworks with a focus on the graph learning module and how
they address practical recommendation challenges such as scalability, fairness,
diversity, explainability and so on. Finally, we share some potential research
directions in this rapidly growing area.Comment: Accepted by UMUA
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