147,983 research outputs found
Detecting Small Query Graphs in A Large Graph via Neural Subgraph Search
Recent advances have shown the success of using reinforcement learning and
search to solve NP-hard graph-related tasks, such as Traveling Salesman
Optimization, Graph Edit Distance computation, etc. However, it remains unclear
how one can efficiently and accurately detect the occurrences of a small query
graph in a large target graph, which is a core operation in graph database
search, biomedical analysis, social group finding, etc. This task is called
Subgraph Matching which essentially performs subgraph isomorphism check between
a query graph and a large target graph. One promising approach to this
classical problem is the "learning-to-search" paradigm, where a reinforcement
learning (RL) agent is designed with a learned policy to guide a search
algorithm to quickly find the solution without any solved instances for
supervision. However, for the specific task of Subgraph Matching, though the
query graph is usually small given by the user as input, the target graph is
often orders-of-magnitude larger. It poses challenges to the neural network
design and can lead to solution and reward sparsity. In this paper, we propose
NSUBS with two innovations to tackle the challenges: (1) A novel
encoder-decoder neural network architecture to dynamically compute the matching
information between the query and the target graphs at each search state; (2) A
novel look-ahead loss function for training the policy network. Experiments on
six large real-world target graphs show that NSUBS can significantly improve
the subgraph matching performance
Neural IR Meets Graph Embedding: A Ranking Model for Product Search
Recently, neural models for information retrieval are becoming increasingly
popular. They provide effective approaches for product search due to their
competitive advantages in semantic matching. However, it is challenging to use
graph-based features, though proved very useful in IR literature, in these
neural approaches. In this paper, we leverage the recent advances in graph
embedding techniques to enable neural retrieval models to exploit
graph-structured data for automatic feature extraction. The proposed approach
can not only help to overcome the long-tail problem of click-through data, but
also incorporate external heterogeneous information to improve search results.
Extensive experiments on a real-world e-commerce dataset demonstrate
significant improvement achieved by our proposed approach over multiple strong
baselines both as an individual retrieval model and as a feature used in
learning-to-rank frameworks.Comment: A preliminary version of the work to appear in TheWebConf'19
(formerly, WWW'19
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