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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Advantages of XLM-R Model for Urdu Sentiment Multi-</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Haoliang Qi</string-name>
          <email>haoliang.qi@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Mingcan Guo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Zhongyuan Han</string-name>
          <email>hanzhongyuan@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Leilei Kong</string-name>
          <email>kongleilei@fosu.edu.cn</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Zhijie Zhang</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Zengyao Li</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Haoyang Chen</string-name>
          <email>hoyo.chen.i@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Foshan University</institution>
          ,
          <addr-line>Foshan</addr-line>
          ,
          <country country="CN">China</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Sentiment Multi-Classification detection has gained much attention in recent years. The multi-label sentiment detection task refers to additional comments based on social media or shopping platforms, which usually contain different personal solid emotions. How to classify these reviews into multiple sentiment types using efficient methods such as machine learning is the main content of this type of task. We describe our XLM-R based method for tracking emotion detection task at FIRE 2022 in this paper. The system uses the XLM-R pretrained model to extract semantic features from Urdu text. After using dynamic learning rate-based tuning, we found that the model is more stable in performance and has a higher score on the test set. In the final result, our system achieved a Micro F1 score of 0.759 and a Macro F1 score of 0.687 in this task and won the first rank in the ORCID: 0000-0002-4977-2138 (M. Guo); 0000-0001-8960-9872 (Z. Han); 0002-4636-3507(L. Kong); 0000-0002-4854-0618 (Z. Zhang); 0000-0001-8472-4150 (Z. Li); 0000-0003-3223-9086 (H. Chen); 0000-0003-1321-5820 (H. Qi)</p>
      </abstract>
      <kwd-group>
        <kwd>sentiment</kwd>
        <kwd>Multi-Classification</kwd>
        <kwd>XLM-R</kwd>
        <kwd>social media</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        With the continuous iteration of Internet technology, more and more people choose to express their
emotional remarks and opinions on social media such as Twitter and Facebook [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. People hope to
openly express their views on social economy, culture, politics, etc. from multiple perspectives. How
to classify these emotional speeches and give them different emotional labels will have a positive effect
on managing and regulating the community and improving the user experience. It can also help
companies and governments to collect rich emotional information. At the same time, it has important
implications both in the research and industrial fields of artificial intelligence. Therefore, some method
needs to be used to identify and divide these speeches, which is the task of multi-label sentiment
detection [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>With the advent of the Internet age, the world is connected as a whole, people from different
countries can communicate freely on the Internet, and thousands of speeches are posted daily, providing
rich language resources for the emotion detection system in past research. Urdu is the official language
of Pakistan. It is the 10th-most widely spoken language in the world, with 230 million total speakers1.
It is widely used in many countries, such as India and Nepal. Because of the large number of speakers
and the wide range of application areas of Urdu, it is crucial to understand the native speakers of Urdu
by analyzing and studying the sentiment classification of Urdu by language processing systems.</p>
      <p>
        In the emotions and threat detection shared tasks at FIRE 2022 task [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ], our team uses the Urdu
script dataset [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] and a pre-trained XLM-R based language processing system for multi-label
classification. To achieve faster model convergence and better model performance, we found that the
Qi)
      </p>
      <p>2022 Copyright for this paper by its authors.
XLM-R model has a strong normalization ability for non-mainstream languages like Urdu, and can well
meet the needs of the task after learning rate tuning, so we use model tuning and adaptive learning rate
tuning to verify the effectiveness of sentiment classification in this dataset.</p>
      <p>The overall result distribution of this paper is as follows. In the second part, we will introduce the
related work and give an overview of the related historical research. We will present our experimental
method in the third part and submit the practical steps and associated details in the fourth part. Finally,
we will analyze the results of our experiments on the official dataset and add a summary to the whole
paper.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Work</title>
      <p>
        People have been working on multi-label sentiment classification for years [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. People usually divide
sentiments according to rules and dictionaries in traditional sentiment classification. For example, J.
Blitzer et al. [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] extended the correspondence learning (SCL) algorithm [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] to sentiment classification
to detect Amazon's products of different product types. Regarding the sentiment of comments, K.
Deneck studied the multi-domain sentiment analysis problem based on SentiWordNet as a lexical
resource [9]. G. Xu et al. proposed an extended dictionary-based Chinese sentiment analysis method on
the rule-based analysis method [10]. Their experiments build a vast sentiment lexicon covering five
domains: hotel, number, fruit, clothing, and shampoo. However, traditional methods do not work well
on social media platforms that generate many comments of different types daily.
      </p>
      <p>In recent years, with the continuous development of neural network and convolutional network
technology and the emergence of transformer models with excellent self-attention mechanisms [11],
rule-based analysis methods have gradually been replaced by feature-supervised learning methods
based on pre-trained models, S. Mahata et al. [12] proposed a model based on bidirectional LSTM and
language tagging using FastText embedding to generate word vectors to train the model, trying to solve
the sentiment analysis problem of English-Tamil code mixed data, B. R. Chakravarthi et al. [13] propose
Long Short Term Memory (LSTM) networks and language-specific pre-processing, they involved
applying an attention layer on contextualized word embeddings and fine-tuning a model pretrained on
the training data of the previous version, DravidianCodeMix-2020, to recognize Tamil and Malayalam
in social media comments Emotions in mixed languages.</p>
      <p>In addition to traditional rule-based sentiment classification and popular neural network pre-trained
model-based sentiment classification, Y. Wu et al. [14] proposed a multimodal sentiment classification
method based on cross-modal prediction centered on text modality, two types of information are mined
from speech modalities and image modalities to assist text modalities, and a text-centric multimodal
feature fusion mechanism is designed to perform feature fusion on multimodal features.</p>
      <p>In previous sentiment analysis tasks, transformers-based models often achieve good results in
different tracks [15]. For example, Y. Bai et al. [16] combined the fine-tuning method of
XLMRoBERTa and CNN through downstream tasks and obtained first place in the mission of Sentiment
Analysis of Dravidian Languages in Code-Mixed Text. In shared task, study by L. Khan et al. [17]
shows that the combination of word n-gram features with LR outperformed other classifiers for
sentiment analysis task, obtaining the highest F1 score of 82.05% using combination of features. In
related supervised classification problems, the content-based word unigram method used by I. Ameer
et al. [18] outperforms other content-based feature-based methods. L. Khan et al. [19] used four text
representations: word n-grams, char n-grams, pretrained fastText, and BERT word embeddings to train
the classifier. Their proposed mBERT model with BERT-pretrained word embeddings outperforms
deep learning, machine learning and rule-based classifiers and achieves an F1 score of 81.49%.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Methodology</title>
    </sec>
    <sec id="sec-4">
      <title>3.1. Model Description</title>
      <p>In this task, our method uses a pre-trained model based on XLM-RoBERTa [20], referred to as
XLM-R. It inherits the method of XLM and draws on the ideas of RoBERTa [21]. Compared with XLM,
XLM-R expands not only the language but also the training data. Therefore, similar to other transformer
structures, the architecture of XLM-R can be and is better suited for text classification tasks. It takes as
input a sequence of no more than 512 tokens and outputs a representation of that sequence. The first
token of the sequence is always [CLS], which contains the particular categorical embedding. As shown
in Figure 1, Urdu tweets are passed into token classification, a linear classification layer that takes the
token sequence and the final hidden state of each Urdu text as input and assigns it to each token. The
cards generate the label output, and the top softmax classifier is used to predict the probability of label
C, which is finally classified into different sentiment labels.</p>
    </sec>
    <sec id="sec-5">
      <title>Neural Network Tuning</title>
      <p>Among many optimization methods, learning rate-based tuning is usually given priority. M. D.
Zeiler [23] uses SGD, Momentum, ADAGRAD, and ADADELTA in a supervised manner. The neural
network is trained to minimize the cross-entropy between the network output predictions and the target
labels, and the results show that the model is sensitive to the parameters of the learning rate, and an
accurate learning rate can quickly converge the model error around the optimal performance that occurs
with momentum.</p>
      <p>Common learning rate change strategies include preset rule learning rate change methods, including
fixed, step, exp, inv, multistep, poly, sigmoid, etc. Compared with non-adaptive learning rate
transformation methods, the model’s absolute value is reduced, and performance impact is. In this task,
we use ReduceLROnPlateau [24] in Keras to adjust the learning rate strategy, based on the Adam [25]
adaptive learning rate algorithm, we detect the change of the Loss index at each epoch. The learning
rate adjustment will be triggered when the Loss no longer decreases within a certain period. The
adjustment strategy is shown in formula 1, where λ is the attenuation multiplication factor.

_
=  × 
_
(1)</p>
      <p>The learning rate decay in our experiments is shown in Figure 2. The value on y-axis in the figure
is magnified by 105 times. According to the algorithm, after it is detected that the Loss no longer
decreases for a certain period, the learning rate will be automatically lowered in the next epoch to make
the model converge to the best performance continuously.</p>
    </sec>
    <sec id="sec-6">
      <title>4. Experiments</title>
    </sec>
    <sec id="sec-7">
      <title>4.1. Data and Pre-Processing</title>
      <p>
        The dataset provided by the task is obtained through Twitter [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], tweets are collected in a CSV file
through the Twitter open API, other kinds of languages are excluded, and only the purest Urdu tweets
are kept. These comments can be divided into seven emotions: anger, disgust, fear, sadness, surprise,
happiness, and neutral. A total of over 10,000 tweets collected are divided into 7,800 training sets and
1,950 test sets. Table 1 shows statistical data according to different categories. All Urdu texts are
normalized with diacritics removed and spaces added after numbers, punctuation, and stop words.
Table 1
The division of train and test sets for different emotion types
      </p>
      <p>Datasets
Urdu Tweets</p>
      <p>Labels
neutral
happiness
surprise
sadness</p>
      <p>fear
disgust
anger
Total
max_len=128, hidden_size=768, epochs=15, learning rate decay parameters are set to factor=0.6,
cooldown=0, min_lr=0, eps=1e-08.</p>
      <p>After loading the model, we choose adamW as the optimizer of the model and cross entropy loss as
the loss function. During training, we set the model to be verified every 100 steps and added the gradient
reset to save the optimal model when confirming the set. The learning rate gradient decays, and finally,
we use the activation function in the output layer to output the predicted label of the model. Figure 3
shows the overall architecture of the experimental process.</p>
      <p>Before the official release of the test set with labels, we divided the training set into 9:1 for model
training and model validation.</p>
    </sec>
    <sec id="sec-8">
      <title>4.2. Results</title>
      <p>We use a variety of evaluation metrics to verify the performance of our model, including Accuracy,
Precision, Recall, Macro F1, Micro F1, and Loss. And we choose Accuracy and Loss among these
metrics to validate the model in train set.</p>
      <p>=</p>
      <p>+
+
+ +
(2)
 = − ∗ [ ∗  ( ) + (1 −  ) ∗  (1 −  )] (3)</p>
      <p>In training the model, we added the methods without learning rate optimization for comparison.
After each epoch, we call the index evaluation method in the sklearn method library to output the
evaluation of the model on the validation set. As shown in Figure 4 and 5, on the two evaluation
indicators of Accuracy and Loss, the model tuned by the adaptive learning rate can converge to near
the best performance to obtain the highest evaluation score. With the adjustment of the learning rate,
the model’s score is gradually stabilized at the optimum on the premise that the Loss function does
not increase, and the performance can be kept stable in the process of continuous iteration. The
performance indicators of the trained model on the validation data set can reach the best, of which the
Accuracy reaches 0.676, and the Loss reaches 0.178.</p>
    </sec>
    <sec id="sec-9">
      <title>5. Conclusion</title>
    </sec>
    <sec id="sec-10">
      <title>6. Acknowledgments</title>
    </sec>
    <sec id="sec-11">
      <title>7. References</title>
      <p>This work is supported by the National Social Science Fund of China (No.18BYY125).</p>
      <p>This paper mainly introduces our work results on Emotion and Threat detection in Urdu task. Our
work combines a pre-trained XLM-R model with adaptive learning rate optimization to solve the
multilabel classification problem of Urdu text. The final ranking effectively validated our method. However,
combined with the final labeled dataset, we noticed that our method still needs to be optimized, such as
paying more attention to the implementation of downstream tasks and the adjustment of model
parameters, ignoring the possible impact of preprocessing such as text filtering on the score. Our work
on sentence type classification and sample equalization processing are still relatively lacking. The next
step will be to preprocess sentence weighting and classification and combine profound learning aspects
with building a more robust model processing system. Our code is available on GitHub2.</p>
      <p>2https://github.com/xiguagaizi/multi_label_classification-main.git
[9] K. Denecke, Are sentiwordnet scores suited for multi-domain sentiment classification? in: 2009</p>
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