Improve CNN and LSTM in sentiment analysis for Vietnamese from data preprocessing phase

Nguyễn Ngọc Duy, Lưu Ngọc Điệp  
IMPROVE CNN AND LSTM IN SENTIMENT  
ANALYSIS FOR VIETNAMESE FROM DATA  
PREPROCESSING PHASE  
Nguyễn Ngọc Duy*, Lưu Ngọc Điệp*  
* Information Technology Department - Posts and Telecommunications Institute of Technology  
Conditional Random Fields [1][2]. The results have been  
highly promising. These machine learning methods are  
based on a sentiment dictionary with a predefined weight  
for each item. An important feature of a sentiment  
dictionary is that it was built for a specific language and  
certain topics. Therefore, if a dictionary is not sufficiently  
good or used for an inappropriate topic, it can affect the  
quality of the sentiment analysis.  
1 Abstract—The deep learning method has achieved good  
results in many application fields, such as image processing and  
computer vision. Recently, this method has also been used in the  
field of natural language processing and has achieved good results  
too. In this area, an issue of concern is subjective opinion  
classification. A subjective opinion is an individual's thinking or  
judgment about a product or a socio-cultural event or issue.  
Subjective opinions have received attention from many producers  
and businesses who are interested in exploiting the opinions of  
the community and scientists. This paper experiments with the  
deep learning model convolution neural network (CNN), long  
short-term memory (LSTM), and the combined model of CNN  
and LSTM. The training data set comprise reviews of cars in  
Vietnamese that are pre-processed according to the method of  
aspect analysis based on an ontology of semantic and sentimental  
approaches. This data set experiment with CNN, LSTM, and  
CNN + LSTM models are used to evaluate the effectiveness of  
the data preprocessing method that was used in this paper. This  
paper tests the sentiment classification with the English  
Sentence Collection Stanford Sentiment Treebank (SST) to  
assess the validity of the test models with the Vietnamese  
opinion set. The non-neural method, SVM, was also tested  
to evaluate the effectiveness of the data processing method  
of the paper.  
Deep learning has only relatively recently been applied  
to natural language processing but has demonstrated good  
results, such as Nal Kalchbrenner et al. in [3] achieving an  
accuracy of 86.8% and Qiudan Li et al. in [4] producing an  
accuracy of 89.81%. The Deep learning method differs  
from other machine learning methods mentioned above in  
a particularly basic way in that is no requirement for a  
sentiment dictionary. Building a sentiment dictionary is a  
difficult task, especially for the less popular languages in  
the world.  
Methods that need a sentiment dictionary are a major  
obstacle to less popular languages in the world. Therefore,  
the approach of the deep learning method brings  
substantial opportunities for less popular languages such as  
Vietnamese to develop the sentiment analysis field in  
natural language processing quickly. Vietnamese has not  
yet had a sentiment dictionary commonly for research. For  
less popular languages when using deep learning methods,  
the important focus is testing, which requires substantial  
time to identify the specific characteristics of these  
languages. From there, it is possible to develop solutions  
to exploit deep learning methods for this field in an  
effective manner.  
Keywords—Classification, CNN, Convolution Neural  
Network, Corpus, Deep Learning, Long Short Term  
Memory, LSTM, Opinion Mining, Sentiment Analysis,  
SVM.  
I. INTRODUCTION  
Everyone has the opportunity to express their thoughts  
and assessments about a product, an event, or other  
problems in the world due to the development of the  
Internet. Such user opinions are increasing in the internet  
environment. This is a particularly useful resource for  
individuals and organizations who want to exploit the  
opinions of the community, as well as individuals who  
consider or want to buy a product. There is a large demand  
for the exploitation of this resource. With a substantially  
large number of opinions, the classification to exploit them  
using scientific methods represents an indispensable  
requirement. Many methods have been proposed and tested  
for the problem of sentiment analysis of each opinion.  
Machine learning methods are highly popular in this field,  
such as Support Vector Machine, Naïve Bayes, and  
Studies on deep learning methods for the field of  
sentiment analysis in Vietnamese, such as [5][6], [7] also  
obtained good results. However, the number of such  
studies has yet to reach a sufficient level. The Vietnamese  
corpus is not yet rich in the topic. This paper develops the  
method of [5] in terms of enriching the corpus and  
ontology. In addition, this research conducted additional  
tests of some deep learning methods in sentence- and  
aspect-level analysis. From there, some characteristics can  
be drawn from using the deep learning method for  
sentiment analysis in Vietnamese as well as a more detailed  
evaluation of the method proposed in [5].  
The rest of the paper is organized as follows: Section 2  
Tác giả liên lạc: Nguyễn Ngọc Duy  
Email: duynn@ptithcm.edu.vn  
Đến tòa soạn: 09/2020, chỉnh sửa: 10/2020, chấp nhận đăng: 10/2020  
Một phần kết quả của bài báo được trình tại hội nghị quốc tế ICICT 2020  
London.  
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IMPROVE CNN AND LSTM IN SENTIMENT ANALYSIS FOR VIETNAMESE FROM DATA PREPROCESSING PHASE  
reviews the related works. Section 3 gives an overview of Word Embedding Layer. This class includes matrices  
the deep learning models used in testing and our of size n x k, representing sentences with n words, each  
preprocessing data method. Section 4 discusses the representing a k-dimensional vector.  
configuration of the deep learning system and the  
This class encodes every word in the selected sentence  
experimental results. Finally, Section  
conclusions.  
5
presents  
into a word vector. Let l R be the sentence length, |D|   
R is the vocabulary size and W(l) Rkx|D| is the matrix  
embedded vectors from k dimensions. The i word in the  
sentence is transformed into a k dimensional vector wi  
using equation (1):  
II. RELATED WORKS  
In the form of sentence-level sentiment classification,  
Nal Kalchbrenner et al. [3] used the dynamic convolution  
neural networks model to model sentences by a Dynamic  
K-Max Pooling operator as a nonlinear sampling function  
to test sentiment classification using the SST corpus. The  
accuracy of [3] was 86.8%. Xingyou Wang et al. [8] also  
tested on the SST opinion set but by using a combination  
of CNN and RNN. The accuracy of [8] was 89.95% on SST  
with three sentiment labels. The accuracy of [8] was 51.5%  
only if Xingyou Wang et al. used SST with five sentiment  
labels. For Pang and Lee's film rating, 2005, the accuracy  
of [8] was found to be 82.28%.  
wi = W(l)xi  
(1)  
where xi is a one-hot vector representation for the i  
word one-hot vector.  
We can use the tool word2vec or Glove to create the  
matrix for this layer.  
Convolution Layer. This class uses convolution to  
process data by sliding a fixed size slide (also called a  
kernel) on the input data matrix to obtain a refined result.  
In the form of aspect-level sentiment classification,  
Quidan Li et al. [4] used the convolutional neural network  
to obtain an accuracy of. The corpus used in the experiment  
was Chinese blog sites. Meanwhile, Dhanush D. et al. [9]  
obtained an accuracy of only 76.1% when using CNN to  
classify the sentiment of restaurant reviews.  
Pooling Layer. This layer is responsible for  
summarizing the result vector of the convolution layer and  
retaining the most important vectors.  
Fully Connected Layer. In a convolution neural  
network, there are one or more fully connected layers after  
the convolution layer. This class is simply a traditional  
neural network that uses the remaining vectors in the upper  
layers as input to produce the final result through training.  
III. APPROACH METHOD  
As mentioned in the previous sections, this research  
will use some models of deep learning methods to  
implement sentiment classification. In the following  
sections, the paper presents an overview of the LSTM and  
CNN models, as well as the combined model of CNN and  
LSTM for sentiment classification testing.  
2) Long Short Term Memory: Long Short-Term  
Memory (LSTM) has four interaction layers and two status  
signals: hidden state and cell state, as shown in Fig. 2.  
At the time t, the LSTM decides that information  
poured into the cell state based on the sigmoid function or  
A. The models for experiments:  
the , floor, forget gate. This function takes ℎt-1 from the  
previous hidden layer and input signal xt in the present to  
create a number in [0, 1] as in formula (2). Whether the  
new information is saved to the cell state or not is based on  
the calculation at the input port with the sigmoid function  
~
1) Convolutional Neural Network: A convolution  
neural network (CNN) is first used in the field of digital  
signal processing. Based on the principle of information  
conversion, scientists have applied this technique to digital  
photo and video processing. In the CNN model as Fig. 1.  
The layers are linked together through a convolution  
mechanism. The next layer is the cumulative result from  
the previous layer. As a result, we have local connections.  
Hence, each neural in the next layer is generated from the  
filters imposed on a local data area of the previous neural  
layer. As a result, we have local connections.  
as formula (3). A vector of new candidate values  
is  
Ct  
created through the tanh layer using formula (4). The cell  
state at time t is calculated by (5) based on the previous cell  
~
state Ct-1, candidate  
và ft function. The ft function can  
Ct  
control the slope that passes through it and explicitly  
deletes or updates memory. The LSTM network decides  
the output based on the cell state. Through the sigmoid  
function, the value of the cell state is calculated by formula  
(6) and reached at the output gate. This value is via the tanh  
function and multiplied by the output of the sigmoid port  
to obtain the ht value via formula (7).  
Each CNN contains a word-embedding layer, a  
convolutional layer, a pooling layer, and a fully connected  
layer.  
Word  
Embedding  
Layer  
Convolutional  
Layer  
Pooling  
Layer  
Fully  
connected  
layer  
Fig. 1. Basic Convolutional Neural Network model [10].  
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Fig. 2. Long Short Term Memory network [11]  
ft = (Wfxt + Ufht-1  
the hyperplane with the largest margin separating the  
points yi = 1 and the points with yi = -1.  
(2)  
(3)  
To find the optimal hyperplane, we need to solve the  
optimization problem. The first we find out maximize W(α)  
in equation (9).  
it = (Wixt + Uiht-1)  
N
N
N
~
1
C = tanh(Wnx +Unh )  
(4)  
W() = −  
  y y K(x , x )  
,i 0 (9)  
t
t
t−1  
2   
i
i
j
i
j
i
j
i=1  
i=1 j=1  
~
C = ft *C +i *C  
(5)  
(6)  
(7)  
t
t−1  
t
t
where N is the number of samples in the training set; xi is  
one of the training vectors; αi is the weight of the training  
sample xi; K is a kernel function which used to measure the  
similarity between two samples. If αi > 0, xi is called a  
support vector.  
o =(W0x +U0h )  
t
t
t−1  
h =o *tanh(C )  
t
t
t
For a sample xj of unknown class, the classification  
corresponds to solving (10).  
3) CNN – LSTM: Convolution layer of CNN creates a  
feature map vector. The number of feature vectors is equal  
to the number of filters used during the convolution. In the  
pooling layer, the best feature map values from each class  
will be chosen to obtain the most important feature of the  
comment. The feature vectors over a fully connected CNN  
network generate a set of parameters at the output of CNN.  
The LSTM Ministry uses output parameters of CNN to  
carry out the process of classifying comments. This  
combined model is shown in Fig. 3.  
r
w = y x  
(10)  
i
i i  
i=1  
If we have accepted an error in the training set (there  
are noise samples) so we have to determine the minimum  
of the expression (3).  
N
|| w ||2 +C  
, 0 ≤ αi ≤ C  
(11)  
i
4) Support Vector Machine [12]: SVM is a supervised  
machine learning algorithm introduced by Vladimir N.  
Vapnik in 1995. The basic idea of SVM is to find a  
hyperplane to separate data. This hyperplane will divide the  
space into different domains that contain a type of data. In  
a two-dimensional space, this hyperplane is a line that  
separates a plane into two parts that each layer is on the  
sides. The distance from the points on the hyperplane  
(called margins) is as far as possible so that the error of  
classification is minimal.  
i=1  
where is a slack variable and allows training patterns  
that exist in the region between margins; the constant C is  
used to adjust for the best results when classified by SVM.  
B. Corpus:  
1) English corpus: Stanford Sentiment Treebank is a  
corpus of film reviews in English [13]. Opinions are  
categorized using five labels: very positive, positive,  
neutral, negative and very negative. To have similarities  
with the Vietnamese corpus, this paper will carry out an  
empirical classification of sentiments using three labels;  
the very positive and the positive will be combined into one  
positive label; very negative and negative classes into one  
negative label.  
Training stage  
Parametes  
Trainging  
LSTM  
CNN  
of model  
data  
2) Vietnamese corpus: The Vietnamese corpus is a  
collection of documents that record the review of car  
objects (Car Opinions in Vietnamese - COV). This topic  
has attracted the attention of many people in large countries  
such as the United States and Germany where car  
ownership is particularly popular, and Vietnam where such  
ownership is popular in some large cities.  
Label of test data  
LSTM  
CNN  
Opinions were collected from the online newspapers  
that record readers' opinions in the auto categories, auto  
forums, and websites of businesses that sell this item. This  
corpus was built and processed according to the method  
presented in [5]. Collected opinions that have been  
Test data  
Testing stage  
processed by this method comprise  
a
so-called  
standardized opinion set (COVn). Opinions that have not  
been processed by this method are referred to as raw  
comments (COVr). The pretreatment method according to  
[5] can be summarized as follows:  
Fig. 3. CNN-LSTM model  
Consider a data set D in two-dimensional space that can  
classify into two classes. Represent data set D as formula  
(8).  
a) Creating a set of aspects for the objects: The  
aspects of cars are technical characteristics that often used  
by manufacturers when introducing products, or customers  
are interested in and assessing products. Each aspect has an  
official name that is commonly used by manufacturers and  
a semantic equivalent. They are the common name that  
D ={(xi ,yi ) | xi Rm, yi {−1,1}}n  
(8)  
i=1  
where yi has a value of 1 or -1 defines the class of point xi.  
Each xi is a real vector with m dimensions. We need to find  
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IMPROVE CNN AND LSTM IN SENTIMENT ANALYSIS FOR VIETNAMESE FROM DATA PREPROCESSING PHASE  
users use when expressing their opinions in the internet  
A: sentiment complements (adjectives or verbs).  
environment.  
The features of the corpus after the above processing  
are shown in Table I.  
The aspect entities are collected by two methods:  
Statistical methods. This method produces statistics  
for the number of nouns that appear in the corpus, from  
which the automotive aspect nouns are selected.  
Table I.  
The Organization of Vietnamese Corpus  
Feature of corpus Quatity  
Sample of cars  
102  
3,214  
6,517  
The word2vec tool. This method is based on the  
characteristics of the correlation of words/phrases in the  
corpus to define aspect and sentiment items further.  
Opinios  
Simple aspect-based sentences  
Testing sentences  
b) Creating the structure of a semantic and sentiment  
vocabulary hierarchical tree: Both aspect and sentiment  
entities are divided into three tiers in the SSVHT ontology  
(Semantic and Sentiment Vocabulary Hierarchical Tree),  
as shown in Fig. 2. Aspect set refers to words/phrases used  
by the manufacturer or user to refer to the components or  
specifications of a car. For example: engine, steering  
wheel, dashboard.  
1,130  
3
(positive, neutral,  
negative)  
Sentiment labels  
Sentences labeled with positive  
polarity  
Sentences labeled with negative  
polarity  
Sentences labeled with neutral  
polarity  
2,134  
2,055  
2,328  
c) Labeling sentences with the semantic and  
sentiment on aspects of object: The labeling of semantics  
and sentiments of the sentence according to the aspect of  
the car is done manually. The labeling process is divided  
into two stages. The first stage carries out the labeling  
according to the aspect of the sentence. The next stage is  
C. Experiment configuration  
1) System configuration: Table II presents the  
the sentimental tagging. The process of labeling will components of the system used in the experiment of this  
remove sentences without Vietnamese accents, without paper.  
sentiment, or not the same subject. Semantic labels are  
nouns or noun phrases belonging to the aspect set of cars.  
The sentimental labels include positive, neutral, and  
negative.  
Table II.  
Component of System  
Operating System  
System Specifications  
Version name  
Ubuntu 20.04  
LTS  
Programminng Language  
Framework Deep Learning  
Python  
Object  
Theano - Keras  
Aspect terms  
2) Specification of models:  
CNN. Activation function is sigmoid (1/(1+e-x)),  
embedding word size is 300, number of filters is 300, filter  
size is 3, dropout is 0.5.  
LSTM. Activation function is sigmoid (1/(1+e-x)),  
dropout is 0.2, embedding word size is tested at 300,  
number of filters tested at 100 and 200.  
Terms having  
the same or  
approximately  
meaning as  
standard terms  
Sentiment  
terms  
CNN+LSTM. The configuration parameters of CNN  
and LSTM when combined are the same as when operating  
independently.  
Fig. 4. Semantic and sentiment vocabulary hierarchical tree  
SVM. Build the feature vector of the sentence by the tf-  
idf method [14]. The kernel function is rbf (Radial Basis  
Function).  
d) Standardizing sentiment aspects of the object:  
Sentiment sentences in the corpus will be re-formulated  
into the simple structured sentence:  
IV. EXPERIMENT  
This paper attempts to change the number of filters in  
the LSTM model. The experiment results with the SST,  
COVr, and COVn corpus are shown in Figs. 5, 6, and 7.  
 +   
()  
()  
()  
 +  +   
 +  +   
Where:  
N: noun representing an aspect.  
R: adverb or adverbs  
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Fig. 5. Accuracy of experimenting on SST and COVn with LSTM  
Model  
Accuracy (%) epoch  
has 200 filters.  
SVM (COVn)  
73.43  
-
Figs. 5, 6, 7 and Table III show the results of sentiment  
classification by the CNN, LSTM, and CNN+LSTM model  
on corpus SST, COVr, and COVn.  
Some results of classifying comments are presented in  
Table IV. Sentences are normalized for aspect-based  
The best values were obtained during the testing of analysis before being sentiment analyzed.  
three sets of comments by the LSTM, CNN, and  
From the experiment results shown in Figs. 5, 6, 7 and  
Table III, the following statements can be made:  
CNN+LSTM model according to the number of iterations  
shown in Table III. The LSTM has 200 filters and CNN  
with 300 filters.  
•
Both CNN and LSTM models operate  
independently, obtaining a fairly low accuracy when  
they analyze aspect-level sentiment. The CNN and  
LSTM models operating independently demonstrated  
an accuracy that fluctuated significantly when the  
number of iterations (epoch) was low (less than 50  
times). Within 80 iterations, the best results showed  
low iterations for both SST and COV opinion sets  
(from 5 to 10 for LSTM and 25 to 30 times for CNN).  
By increasing the number of iterations and filters, the  
result was more stable and reliable.  
Fig. 6. Accuracy of experiments on SST and COVn with  
•
The accuracy of the combined CNN and  
LSTM has 100 and 200 filters.  
LSTM model is better than the accuracy of each  
model when they run independently, as shown in  
Table III. This accuracy improved by approximately  
10% compared to when these models were running  
separately.  
•
The LSTM model was the least effective of the  
models tested. This model ran quite slowly and had  
the lowest accuracy for all three test sets tested.  
•
The aspect-level data preprocessing method  
for comments based on SSVHT ontology improves  
accuracy in both CNN, LSTM, and CNN + LSTM  
models. In particular, the CNN + LSTM model has an  
accuracy difference of up to 4% when it was trained  
by the preprocessed dataset compared to the raw  
dataset.  
Fig. 7. Accuracy of experiment on COVr and COVn with  
LSTM has 200 filters.  
Table III.  
Model  
Best Accuracy Results of Each Model.  
Accuracy (%) epoch  
•
The SVM method achieved accuracy not high.  
LSTM (100 filter – COVr)  
LSTM (100 filter – COVn)  
LSTM (100 filter – SST)  
LSTM (200 filter – COVr)  
LSTM (200 filter – COVn)  
LSTM (200 filter – SST)  
CNN (300 filter – COVr)  
CNN (300 filter – COVn)  
CNN (300 filter – SST)  
61.65  
63.65  
61.12  
62.66  
62.91  
61.55  
66.77  
5
5
The difference in accuracy when testing on two  
datasets is also not high. The SVM method is not  
based on the neural model as deep learning methods.  
Therefore, it can be seen that the data preprocessing  
method of the paper is consistent with the deeper  
learning models  
3
3
5
Although the results obtained on SST and COV tests  
differed with respect to accuracy, there were many  
similarities in the results achieved in each model as well as  
between models. Hence, CNN and LSTM in particular, and  
deep learning in general, do not have any language barriers  
as well as the subject of sentence-level and aspect-level  
sentence sentiment classification.  
10  
25  
70.64 25, 30  
65.89  
75.03  
20  
25  
CNN + LSTM (100 filter –  
COVr)  
CNN + LSTM (100 filter –  
COVn)  
78.83  
70.86  
75.39  
40  
10  
50  
CNN + LSTM (100 filter – SST)  
CNN + LSTM (200 filter –  
COVr)  
CNN + LSTM (200 filter –  
COVn)  
80.13  
35  
CNN + LSTM (200 filter – SST)  
78.61  
73.36  
15  
-
SVM (COVr)  
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IMPROVE CNN AND LSTM IN SENTIMENT ANALYSIS FOR VIETNAMESE FROM DATA PREPROCESSING PHASE  
Table IV. RESULTS OF CLASSIFICATION AND DISCUSSION OF THE MODELS.  
Sentence  
Type  
Label  
CNN  
LSTM  
CNN+LSTM  
Xèng hạt dẻ cho một em hạng B  
Giá bán hạt dẻ cho một em hạng B  
Các bác nghĩ sao chứ trông em nó ẻo lả quá ạ  
Các bác nghĩ sao chứ tổng thể em nó ẻo lả quá ạ Standardized Negative  
Raw  
Standardized  
Raw  
Positive  
Positive  
Negative  
Neutral  
Positive  
Neutral  
Negative  
Positive  
Positive  
Neutral  
Positive  
Neutral  
Negative  
Positive  
Positive  
Neutral  
Positive  
Neutral  
Negative  
Positive  
Positive  
1
2
3
Công nhận khoang lái em này nhìn khá chất  
Công nhận nội thất em này nhìn khá chất  
Lái qua những đoạn xóc em cảm thấy nó có vẻ  
ọp ẹp lắm  
Vận hành qua những đoạn xóc em cảm thấy nó  
có vẻ ọp ẹp lắm  
Ôm vô lăng trên cao tốc mớ thầy nó chao liệng  
như thế nào nhé bác  
Vận hành trên cao tốc mới thấy nó chao liệng  
như thế nào nhé bác  
Raw  
Positive  
Standardized Positive  
Raw Negative  
Negative  
Negative  
Neutral  
Negative  
Negative  
Neutral  
Negative  
Negative  
Negative  
Negative  
4
5
Standardized Negative  
Raw Negative  
Standardized Negative  
Negative  
Negative  
neural networks in Chinese microblogging systems”,  
Knowledge-Based Systems, Vol 107, 2016, pp 289-300.  
[5] Duy Nguyen Ngoc, Tuoi Phan Thi and Phuc Do, “A data  
preprocessing method to classify and summarize aspect-  
based opinions using deep learning”, Asian Conference on  
Intelligent Information and Database Systems. Springer,  
2019. pp. 115-127.  
[6] Vo, Q. H., Nguyen, H. T., Le, B., & Nguyen, M. L., “Multi-  
channel LSTM-CNN model for Vietnamese sentiment  
analysis”, In: 2017 9th international conference on  
knowledge and systems engineering (KSE). IEEE, 2017, pp  
24-29.  
[7] PHAM, Thai-Hoang; LE-HONG, Phuong, “The importance  
of automatic syntactic features in Vietnamese named entity  
recognition”, arXiv preprint arXiv:1705.10610, 2017.  
[8] Xingyou Wang, Weijie Jiang, Zhiyong Luo, “Combination  
of Convolutional and Recurrent Neural Network for  
Sentiment Analysis of Short Texts”. In Proceedings of  
COLING 2016, the 26th International Conference on  
Computational Linguistics: Technical Papers. 2016. pp  
2428-2437.  
V. CONCLUSION  
This paper achieved good results for aspect-level  
sentiment analysis using the CNN and the LSTM model,  
particularly the model combining CNN + LSTM by  
helping the data preprocessing method based on an  
ontology of semantic and sentimental approaches. This  
data preprocessing method helps the learning process of  
CNN and LSTM models, and combined models can be  
performed more rapidly if the CNN and LSTM are  
separated. This data preprocessing method enables the  
CNN+LSTM model to achieve good results with a small  
corpus. The importance of this method is in understanding  
the subject of the corpus. The data preprocessing method  
was tested in the aspect-level sentiment classification.  
Next, the authors will test document-level sentiment  
classification as well as improve the method so that we can  
obtain good results for that problem.  
The test results of this paper on the SST corpus in  
English and COV corpus in Vietnamese demonstrate that  
the deep learning method does not meet the limitations for  
different languages. This feature of the deep learning  
method is of high significance to the less popular  
languages in the world, including Vietnamese. It will help  
these languages develop the sentiment analysis field in  
natural language processing more rapidly.  
[9] Dhanush, D., Thakur, A. K., & Diwakar, N. P, “Aspect-  
based sentiment summarization with deep neural networks”,  
International Journal of Engineering Research  
&
Technology, Vol 5, Issue 5, 2016, pp 371-375.  
[10] Yoon Kim, “Convolutional neural networks for sentence  
classification”, in Proceedings of the 2014 Conference on  
Empirical Methods in Natural Language Processing,  
EMNLP, 2014, pp 1746-1751.  
[11] Lei Zhang, Suai Wang, and Bing Liu, “Deep learning for  
sentiment analysis: a survey”, Wiley Interdisciplinary  
Reviews: Data Mining and Knowledge Discovery, Vol 8,  
Issue 4, 2018, pp e1253.  
[12] VAPNIK, Vladimir; VAPNIK, Vlamimir. Statistical  
learning theory Wiley. New York, 1998, 1: 624  
[13] Socher, R., Perelygin, A., Wu, J., Chuang, J., Manning, C.  
D., Ng, A., & Potts, C. “Recursive deep models for semantic  
Acknowledgments: This article received some valuable  
advice from Prof. Dr. Phan Thi Tuoi. The authors are  
grateful to Professor.  
REFERENCES  
[1] Balazs, Jorge A., and Juan D. Velásquez, "Opinion mining  
and information fusion: a survey", Information Fusion Vol  
27, 2016, pp 95-110.  
[2] MORAES, Rodrigo; VALIATI, JoãO Francisco; NETO,  
compositionality  
over  
a
sentiment  
treebank”.  
Wilson P.  
GaviãO,  
“Document-level  
sentiment  
In Proceedings of the 2013 conference on empirical  
methods in natural language processing, 2013, pp 1631-  
1642.  
classification: an empirical comparison between SVM and  
ANN”, Expert Systems with Applications, Vol 40, No. 2,  
2013, pp 621-633.  
[14] DIERK, S. F. The SMART retrieval system: Experiments in  
[3] Nal Kalchbrenner, Edward Grefenstette, Phil Blunsom, “A  
convolutional neural network for modelling sentences”.  
arXiv preprint arXiv:1404.2188, 2014.  
[4] Qiudan Li, Zhipeng Jin, Can Wang, Daniel Dajun Zeng,  
“Mining opinion summarizations using convolutional  
automatic  
Ed.(Englewood Cliffs, NJ: Prentice-Hall, 1971, 556 pp.,  
$15.00). IEEE Transactions on Professional  
Communication, 1972, 1: 17-17.  
document  
processing—Gerard  
Salton,  
SOÁ 03 (CS.01) 2020  
TAÏP CHÍ KHOA HOÏC COÂNG NGHEÄ THOÂNG TIN VAØ TRUYEÀN THOÂNG  
29  
                           
Nguyễn Ngọc Duy, Lưu Ngọc Điệp  
TĂNG CƯỜNG HIỆU NĂNG CHO LSTM AND  
CNN TRONG PHÂN TÍCH CẢM XÚC TIẾNG  
VIỆT TỪ GIAI ĐOẠN TIỀN XỬ LÝ DỮ LIỆU  
Tóm tắt—Phương pháp học sâu đã đạt được kết quả  
tốt trong nhiều lĩnh vực ứng dụng, chẳng hạn như xử lý  
hình ảnh và thị giác máy tính. Gần đây, phương pháp  
này cũng đã được sử dụng trong lĩnh vực xử lý ngôn ngữ  
tự nhiên và cũng đạt được kết quả tốt. Trong lĩnh vực  
này, một vấn đề cần quan tâm là phân loại ý kiến chủ  
quan. Ý kiến chủ quan là suy nghĩ hoặc nhận định của  
cá nhân về sản phẩm, sự kiện hoặc vấn đề văn hóa xã  
hội. Ý kiến chủ quan đã nhận được sự quan tâm của  
nhiều nhà sản xuất, kinh doanh quan tâm, khai thác ý  
kiến của cộng đồng và các nhà khoa học. Bài báo này  
thử nghiệm với mạng nơ-ron tích chập của mô hình học  
sâu (CNN), bộ nhớ ngắn hạn dài (LSTM) và mô hình kết  
hợp của CNN và LSTM. Bộ dữ liệu đào tạo bao gồm các  
bài đánh giá về ô tô bằng tiếng Việt được xử lý trước  
theo phương pháp phân tích khía cạnh dựa trên bản thể  
luận của các phương pháp tiếp cận ngữ nghĩa và cảm  
tính. Thử nghiệm tập dữ liệu này với các mô hình CNN,  
LSTM và CNN + LSTM được sử dụng để đánh giá hiệu  
quả của phương pháp tiền xử lý dữ liệu đã được sử dụng  
trong bài báo này. Bài báo này kiểm tra sự phân loại ý  
kiến với Ngân hàng Bộ sưu tập câu tiếng Anh Stanford  
Sentiment Tree (SST) để đánh giá tính hợp lệ của các  
mô hình thử nghiệm với tập ý kiến tiếng Việt. Phương  
pháp phi thần kinh, SVM, cũng đã được thử nghiệm để  
đánh giá hiệu quả của phương pháp xử lý dữ liệu của bài  
báo  
Từ khóa—CNN, học sâu, khai phá ý kiến, kho ngữ  
liệu, LSTM, mạng neural tích chập, phân tích cảm xúc,  
SVM.  
Nguyen Ngoc Duy is currently  
a lecturer of the Faculty of  
Information Technology at  
Posts  
and  
Telecommunications Institute  
of Technology in Vietnam,  
campus Ho Chi Minh City. I  
received M.Sc. in Computer  
Science in the Ho Chi Minh City  
University of Technology,  
Vietnam (HCMUT) in 2005,  
and became Ph.D. Candidate  
at HCMUT since 2016. My  
research interests include  
machine learning, data mining,  
and  
natural  
language  
processing.  
Luu Ngoc Diep is currently a  
lecturer of the Faculty of  
Information Technology at  
Posts  
and  
Telecommunications Institute  
of Technology in Vietnam,  
campus Ho Chi Minh City. I  
received M.Sc. Electronics and  
Telecommunications in the Ho  
Chi Minh City University of  
Technology,  
(HCMUT) in 2003.  
Vietnam  
SOÁ 03 (CS.01) 2020  
TAÏP CHÍ KHOA HOÏC COÂNG NGHEÄ THOÂNG TIN VAØ TRUYEÀN THOÂNG  
30  
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