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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Novel Initial Reminder Framework for Acronym Extraction</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Xiusheng Huang</string-name>
          <email>huangxiusheng2020@ia.ac.cn</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
          <xref ref-type="aff" rid="aff4">4</xref>
          <xref ref-type="aff" rid="aff5">5</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Bin Li</string-name>
          <email>libincn@hnu.edu.cn</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff5">5</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Fei Xia</string-name>
          <email>xiafei2020@ia.ac.cn</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
          <xref ref-type="aff" rid="aff4">4</xref>
          <xref ref-type="aff" rid="aff5">5</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Yixuan Weng</string-name>
          <email>wengsyx@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
          <xref ref-type="aff" rid="aff4">4</xref>
          <xref ref-type="aff" rid="aff5">5</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Acronym extractions</institution>
          ,
          <addr-line>The initials, Initial Reminder Framework</addr-line>
          ,
          <country>Neighborhood Search Strategy</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>College of Electrical and Information Engineering, Hunan University</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Comercio de Cacao (FICC) Federacion Internacional de Ia Industria del</institution>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>National Laboratory of Pattern Recognition, Institute of Automation Chinese Academy Sciences</institution>
          ,
          <addr-line>Beijing, 100190</addr-line>
          ,
          <country country="CN">China</country>
        </aff>
        <aff id="aff4">
          <label>4</label>
          <institution>School of Artificial Intelligence, University of Chinese Academy of Sciences</institution>
          ,
          <addr-line>Beijing, 100190</addr-line>
          ,
          <country country="CN">China</country>
        </aff>
        <aff id="aff5">
          <label>5</label>
          <institution>XLII (I) Consejo Mundial de la Paz (CMP) Federacion Internacional de</institution>
        </aff>
      </contrib-group>
      <abstract>
        <p>Acronym extraction is committed to extracting acronyms (e.g., short-forms) and their meaning (e.g., long-forms) from the original document, this is one of the key and challenging tasks in scientific document understanding (SDU@AAAI-22) tasks. Previous work regarded them as a task of named entity recognition, ignoring the relationship between acronyms and their meaning, especially the importance of initials. In this paper, we propose a novel Initial Reminder Framework (IRF) for acronym extraction task. Specifically, the IRF recognize the span of acronym for the first time, combined with the initial information, and recognized their meaning again. At the same time, considering that acronyms are often close to their meaning, the IRF adopts Neighborhood Search Strategy. Experiments on two acronym extraction dataset show IRF outperforms the previous methods by 5.90/7.10 F1. Further analysis reveals IRF is efective in extracting short-forms and long-forms.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Danish.</title>
      <p>the acronym can correspond to the initial of the long- two acronym extraction data sets, including Spanish and</p>
      <sec id="sec-1-1">
        <title>1. Introduction</title>
        <p>
          Acronym extraction is a task to identify acronyms and
their meanings, which is very important for scientific
previous method regards this task more as a sequence
annotation task[
          <xref ref-type="bibr" rid="ref3 ref4 ref5">3, 4, 5</xref>
          ], and the model will recognize the
acronyms and long-term.
        </p>
        <p>The context of acronyms often have more obvious
characteristics, for example, there are brackets around
acronyms, or acronyms themselves have a specific format,
which leads to a higher accuracy of identifying acronyms.
However, the accuracy of identifying long-term is
relatively low, and there are some problems, such as
inaccurate identification and no identification.</p>
        <p>As shown in Figure 1, in a document, we need to
identify the acronyms and long-term. The context of
acronyms often has some characteristics (e.g. brackets),
nition is a challenge. It needs to have a certain
understanding of the document content. The better solution
is to know what the corresponding acronym is before
extracting long term, which will help model recognition
of long term.</p>
        <p>Through Figure 1, we can find that each character of
orange text represents long term, and red text represents
initials. At the same time, red, blue and black lines indicate the
correspondence between initials and acronyms, respectively.
(Dataset: Spanish)
In this paper, we propose a novel Initial Reminder
Framework (IRF) for acronym extraction task. Through
experiments, we find that the model has high accuracy in
acronym recognition than long-term recognition.
Specifof identifying acronyms, the F1 score is only 83%. At the
same time, considering the correlation between acronyms
and long-term, IRF first completes the task of identifying
acronyms. On this basis, combined with the initial
information contained in acronyms, IRF further identifies
long-term. We verify the efectiveness of our method on
We summarize our contributions as follows:
• We introduce a fresh perspective to revisit the
acronym extraction task with a principled
problem formulation, which implies a general
algorithmic framework that helps the identify long-term
• we propose a novel Initial Reminder Framework
(IRF) for acronym extraction task. Specifically,
IRF makes use of the high accuracy of acronym
recognition and helps the model recognize
longterm by integrating the initial information.
• We conduct experiments on two acronym
extraction datasets. Experimental results demonstrate
that our IRF model can achieves state-of-the-art
performance compared with baselines.</p>
      </sec>
      <sec id="sec-1-2">
        <title>2. Task introduction</title>
        <sec id="sec-1-2-1">
          <title>2.1. Problem definition</title>
          <p>training (5928), development (741), and testing (741) sets
from the whole dataset. As shown in Table 2, the Danish
dataset is divided into training (3082), development (385),
and testing (160) sets according to the whole dataset.</p>
          <p>Both datasets have been manually labeled, where the
label is a list of position boundaries.</p>
          <p>We regard the acronym extraction task as a sequence
annotation task. Diferent from the previous methods,
considering the high accuracy of acronym recognition,
we will first recognize the acronym, and then use the 3. Methodology
character information of the acronym to recognize the
long-term. Given a document D = { 1,  2, … ,   }, the In this section, we will introduce our proposed IRF model.
initials of each word in the document is I = { 1,  2, … ,   }. IRF utilizes the corresponding relationship between the
Utilizing our IRF model, we will get each acronyms and characters of acronyms and the initials of long-term, this
long-term : will efectively help the model improve the accuracy of
long-term recognition.
,  =</p>
          <p>IRF ( 1,  2, … ,   ;  1,  2, … ,   )</p>
          <p>(1)
where A refers to acronyms and L refers to long-term.</p>
        </sec>
        <sec id="sec-1-2-2">
          <title>2.2. Evaluation metric</title>
        </sec>
        <sec id="sec-1-2-3">
          <title>3.1. Encoder</title>
          <p>Given a document D = { 1,  2, … ,   }, and the initials
of each word in the document is I = { 1,  2, … ,   }. We
leverage the pre-trained language model as an encoder
to obtain the embedding as follows:
The online results will be evaluated with the
macroaveraged precision, recall, and F1 scores. The final score
is the prediction correctness of short-form (i.e., acronym)
and long-form (i.e., phrase) boundaries in the given sen-  = BERT Encode ( 1,  2, … ,   ;  1,  2, … ,   ) (2)
tence. The short-form or long-form predictions are
correct once the beginning and the end of the position of the where  = [ℎ 1, ℎ2, … , ℎ ] is the embedding of each
predicted short-form or long-form are equal to the label token,  is the embedding of each initial.
respectively. The oficial score is counted based on the
macro average of short-form and long-form F1 scores.</p>
        </sec>
        <sec id="sec-1-2-4">
          <title>3.2. Acronyms Tagger</title>
        </sec>
        <sec id="sec-1-2-5">
          <title>2.3. Dataset introduction</title>
          <p>This task contains various multi-lingual datasets
composed of document sentences in science fields. Among
them, the statistics of the Spanish and the Danish datasets
are shown in Table 1. The Spanish dataset is divided into
The low level tagging module is designed to recognize
all possible acronyms in the input sentence by directly
decoding the encoded vector  produced by the N-layer
BERT encoder. More precisely, it adopts two identical
binary classifiers to detect the start and end position of
acronyms respectively by assigning each token a binary
tag (0/1) that indicates whether the current token
corresponds to a start or end position of a acronym. The
detailed operations of the acronyms tagger on each token
are as follows:
   = (</p>
          <p>)
   = (  ℎ +  )
(3)
(4)
where  
  and</p>
          <p>represent the probability of
identifying the i-th token in the input sequence as the start
and end position of a acronym, respectively. The
corresponding token will be assigned with a tag 1 if the
probability exceeds a certain threshold or with a tag 0
otherwise. ℎ is the encoded representation of the i-th
token in the input sequence, i.e., ℎ = [] , where  
and</p>
          <p>represent the trainable weight, and  
are bias and  is the sigmoid activation function.</p>
        </sec>
        <sec id="sec-1-2-6">
          <title>3.3. Long-term Tagger</title>
          <p>Considering that each acronym and its meaning are
always connected together, we utilize Neighborhood
Search Strategy to select the context near the search
acronym, so as to extract the correct long-term.</p>
          <p>The high level tagging module simultaneously
identiifes the long-term with respect to the acronyms obtained
at lower level. As show in the Figure 2, for the acronyms
, We search for its corresponding long term in a
limited context. Diferent from acronyms tagger directly
decoding the encoded vector  , the Long-term Tagger
takes the acronyms features and initial features into
account as well. The detailed operations of the Long-term</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>Tagger on each token are as follows:</title>
      <p>Neighborhood Search Strategy
and end position of a long-term respectively, and   ℎ
represents the encoded representation vector of the k-th
subject detected in low level module, the  
represents the embedding of initials (i.e., C, M and P). For each
acronym, we iteratively apply the same decoding process

and
on it. Meanwhile, for the Neighborhood Search Strategy,
we set the search length to  , where the  is a
hyperparameter which is the longest distance between acronyms
and long in the statistical training set.
4. Experiments
4.1. Baseline models</p>
      <p>
        on the website1.
• Rule-based method The rule-based baseline
method is proposed to adopt manual rules for
this task [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. The words with more than 60% of
their characters are upper-cased to be selected
as acronyms. The long-forms are chosen once
the initial characters of the preceding words are
before an acronym. The whole codes are online
• BiLSTM-CRF model The bidirectional LSTM
[
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] is an extension of LSTM that adopts a
forward and backward LSTM network for sequence
processing, where the links of the network is used
as the output layer (Huang et al., 2015). The
BiLSTM structure gathers contextual information
simultaneously from the past with bidirectional.
      </p>
      <p>
        Besides, the BiLSTM has advantages in the LSTM
that avoids gradient vanishing compared with
the RNN. The output hidden state of BiLSTM will
be concatenated between the forward LSTM  
and backward LSTM   networks as final output
[  ,   ]. This feature is calculated with the
crossentropy loss with the target token-level labels.
• BERT-CRF model The BERT-CRF [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] is
implemented with the token-level neural network with
the conditional random field (CRF) on top, where
the backbone of this baseline can choose from the
Mbert[]. The Mbert is the multilingual masked
language model (MLM) trained with multiple
corpora. The backbone has varients such as base
and large, which are chosen as our baselines. As
for the input tokens, the backbone encodes the
tokens to the encoding. The final classification
scores are obtained in the CRF layer, where the
tag is used as the transition matrix. The matrix
contains two states including the beginning (B)
1https://github.com/amirveyseh/AAAI-22-SDU-shared-task-1ent varients of the Roberta as our baselines, in- built upon
      </p>
      <sec id="sec-2-1">
        <title>4.2. Datasets</title>
        <p>We evaluated our method on two acronym extraction
datasets</p>
        <p>mainly including Spanish dataset and Danish
dataset. Specifically, the Spanish dataset has 7410
samples, and the Danish dataset has 3853 samples [10].</p>
      </sec>
      <sec id="sec-2-2">
        <title>4.3. Implementation Detail</title>
        <p>
          We used cased BERT-base, or RoBERTa-large as the
encoder on Spanish and Danish dataset. All models are
implemented based on the open-source transformers
library of huggingface [11]. we initialize the model with
mbert [12]. We use mixed-precision training [13] based
on the Apex library. Our model is optimized with AdamW
[14] using learning rates ∈ [2−5, 3−5, 5−5, 1−4]
, with
a linear warmup [15] for the first 6% steps followed by
a linear decay to 0. We report the mean and standard
deviation of F1 on the development set by conducting 5
runs of training using diferent random seeds. We utilize
the In-trust loss [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ] function to optimize the model.
        </p>
      </sec>
      <sec id="sec-2-3">
        <title>4.4. Results</title>
        <p>In the Spanish and Danish datasets, we compare IRF with
In this paper, we propose a novel Initial Reminder
Framebaselines, including Rule-based, BiLSTM-CRF, BERT- work (IRF) for acronym extraction task. Specifically,
CRF and Roberta-CRF. Results in Table 3 and Table 4
2https://competitions.codalab.org/competitions/34925results
85.31 (+ 4.89)</p>
        <p>84.23 (+ 5.12)
90.13 (+ 6.69)</p>
        <p>89.07 (+ 6.88)
WENGSYX2.</p>
      </sec>
      <sec id="sec-2-4">
        <title>4.5. Analysis</title>
        <p>show that PAEE performs better than these methods.
Specifically, in Spanish dataset, our best model, IRF
Val/Test set than Roberta-CRF. In addition, in Danish
dataset, IRF built upon  
 

, is +7.65 / +7.10 F1
better on Val/Test set than Roberta-CRF. They obtain
new state-of-the-art(SOTA) results, we held the first
position on the CodaLab scoreboard under the alias
, is +5.66 / +5.90 F1 better on
Considering the correlation between acronyms and the
initials of long-term, our IRF establishes the relationship
between acronyms and long-term, which improves the
accuracy of extracting long and the overall performance
of the model. In order to further explore the efectiveness
of our method, we analyze the accuracy of identifying
long-term in the acronym extraction task. As show in
improve the accuracy of extracting long-term.
Specifically, on the F1 score, we have a maximum performance
improvement of 5%. The significant increase of the
recognition accuracy of the model in long term will help to
improve the overall performance of the model.</p>
        <sec id="sec-2-4-1">
          <title>5. Conclusion</title>
          <p>IRF utilizes Acronyms Tagger to recognize the span of Roberta: A robustly optimized bert pretraining
apacronym for the first time. Then combining with the ini- proach, arXiv preprint arXiv:1907.11692 (2019).
tial information, IRF utilizes Long-term Tagger to recog- [10] S. Y. R. J. F. D. T. H. N. Amir Pouran Ben
Veynize the long-term. IRF captures the relationship between seh, Nicole Meister, MACRONYM: A
Largeacronyms and long-term in the dataset. Meanwhile, uti- Scale Dataset for Multilingual and Multi-Domain
lizing the character information in acronyms, the IRF Acronym Extraction, in: arXiv, 2022.
improves the accuracy of long-term recognition. We con- [11] T. Wolf, L. Debut, V. Sanh, J. Chaumond, C.
Deduct experiments on two acronym extraction datasets. langue, A. Moi, P. Cistac, T. Rault, R. Louf, M.
FunExperimental results demonstrate that our IRF model towicz, et al., Huggingface’s transformers:
State-ofcan achieves state-of-the-art performance compared with the-art natural language processing, arXiv preprint
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