*Corresponding author: Yawen Li (warmly0716@126.com).
Unsupervised Semantic Representation Learning of Scientific
Literature Based on Graph Attention Mechanism and
Maximum Mutual Information
Hongrui Gao1, Yawen Li2*, Meiyu Liang1, Zeli Guan1
1Beijing Key Laboratory of Intelligent Communication Software and Multimedia, School of Computer Science
(National Pilot Software Engineering School), Beijing University of Posts and Telecommunications, Beijing 100876
2School of Economics and Management, Beijing University of Posts and Telecommunications, Beijing 100876
Abstract: Since most scientific literature data are
unlabeled, this makes unsupervised graph-based semantic
representation learning crucial. Therefore, an
unsupervised semantic representation learning method of
scientific literature based on graph attention mechanism
and maximum mutual information (GAMMI) is proposed.
By introducing a graph attention mechanism, the
weighted summation of nearby node features makes the
weights of adjacent node features entirely depend on the
node features. Depending on the features of the nearby
nodes, different weights can be applied to each node in
the graph. In addition, an unsupervised graph contrastive
learning strategy is proposed to solve the problem of
being unlabeled and scalable on large-scale graphs. By
comparing the mutual information between the positive
and negative local node representations on the latent
space and the global graph representation, the graph
neural network can capture both local and global
information. Experimental results demonstrate
competitive performance on various node classification
benchmarks, achieving good results and sometimes even
surpassing the performance of supervised learning.
Keywords: Semantic representation; Graph neural
network; Graph attention; Maximum mutual information
1 Introduction
Currently, scientific literature resources are flooding the
Internet [1][2]. How to extract important information
from scientific literature and effectively represent them
semantically is the core issue to realize the classification,
retrieval, and recommendation of scientific literature.
Traditional methods mainly rely on expert experience to
construct artificial features to represent scientific
literature. For example, in academic information retrieval,
literature titles and abstract texts are used to construct an
inverted index [3]. But every time new text data is added,
it is tedious to rebuild the entire index. In literature
classification and recommendation systems, bag of words
model [4], vector space model, and topic model [5] are
used to build scientific literature vectors. However, the
shortcomings of the bag of words model are obvious.
When the vocabulary increases, there are at most ten
words used for each sentence, which leads to the sparse
matrix of each sentence, seriously affecting the memory
and computing resources. Mainstream methods can map
data into vector space and operate on vectors to complete
specific tasks[6-9][13]. However, the existing vector
space model-based document processing methods are
based on word frequency information[10][11]. The
similarity of two documents depends on the number of
common words, and the semantic ambiguity of natural
language cannot be distinguished.
Deep learning-based representation learning has received
extensive attention recently[12][14-16]. The fundamental
drawback is that the neural language model only focuses
on the text semantics information of academic
documents[17] while ignoring the relationship between
academic documents. Some researchers solve the
problem of imperfect data characteristics by means of
multi-agent [18-19]. More and more researchers are
fusing different features to better complete deep learning
tasks[20-24].
In view of this, graph neural network [25] is proposed to
extract the relationship structure information between
documents from the document citation network and fuse
them with the semantic information of the document text,
so as to construct the representation vector of academic
documents. However, most of the existing studies use
supervised graph neural networks to learn feature
representations of documents[26][27], which have
following two drawbacks: For specific tasks, supervised
graph neural networks need to develop a huge amount of
excellently labeled data; The feature representation of
text obtained by supervised graph neural network[28]is
highly coupled with the task of labeling datasets, and it is
difficult to directly transfer to other tasks, resulting in
poor universality of feature representation.
Compared to supervised learning method, unsupervised
graph neural networks perform better. Because they can
directly learn general document feature representations
from unlabeled document network data[29].
Based on this, this paper proposes an unsupervised
semantic representation learning method for scientific
literature based on graph attention mechanism and
maximum mutual information (GAMMI). The following
are this paper’s main contributions:
1) A semantic representation learning method for
scientific literature based on graph attention mechanism
and maximum mutual information is proposed. By