Guohua Liu

Guohua Liu


Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 November 2021 in Applied Sciences
Verified
Journal Article
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MARJAN Ali KAMYABMARJAN Ali KAMYAB
MARJAN Ali KAMYAB
GLGuohua Liu
Guohua Liu
MAMichael Adjeisah
Michael Adjeisah
Sentiment analysis (SA) detects people’s opinions from text engaging natural language processing (NLP) techniques. Recent research has shown that deep learning models, i.e., Convolutional Neural Network (CNN), Recurrent Neural Network (RNN), and Transformer-based provide promising results for recognizing sentiment. Nonetheless, CNN has the advantage of extracting high-level features by using convolutional and max-pooling layers; it cannot efficiently learn a sequence of correlations. At the same time, Bidirectional RNN uses two RNN directions to improve extracting long-term dependencies. However, it cannot extract local features in parallel, and Transformer-based like Bidirectional Encoder Representations from Transformers (BERT) are the computational resources needed to fine-tune, facing an overfitting problem on small datasets. This paper proposes a novel attention-based model that utilizes CNNs with LSTM (named ACL-SA). First, it applies a preprocessor to enhance the data quality and employ term frequency-inverse document frequency (TF-IDF) feature weighting and pre-trained Glove word embedding approaches to extract meaningful information from textual data. In addition, it utilizes CNN’s max-pooling to extract contextual features and reduce feature dimensionality. Moreover, it uses an integrated bidirectional LSTM to capture long-term dependencies. Furthermore, it applies the attention mechanism at the CNN’s output layer to emphasize each word’s attention level. To avoid overfitting, the Guasiannoise and GuasianDroupout are adopted as regularization. The model’s robustness is evaluated on four English standard datasets, i.e., Sentiment140, US-airline, Sentiment140-MV, SA4A with various performance matrices, and compared efficiency with existing baseline models and approaches. The experiment results show that the proposed method significantly outperforms the state-of-the-art models.
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17 March 2022 in PeerJ Computer Science
Verified
Journal Article
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MARJAN Ali KAMYABMARJAN Ali KAMYAB
MARJAN Ali KAMYAB
GLGuohua Liu
Guohua Liu
Abdur RasoolAbdur Rasool
Abdur Rasool
MAMichael Adjeisah
Michael Adjeisah
Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN) have been successfully applied to Natural Language Processing (NLP), especially in sentiment analysis. NLP can execute numerous functions to achieve significant results through RNN and CNN. Likewise, previous research shows that RNN achieved meaningful results than CNN due to extracting long-term dependencies. Meanwhile, CNN has its advantage; it can extract high-level features using its local fixed-size context at the input level. However, integrating these advantages into one network is challenging because of overfitting in training. Another problem with such models is the consideration of all the features equally. To this end, we propose an attention-based sentiment analysis using CNN and two independent bidirectional RNN networks to address the problems mentioned above and improve sentiment knowledge. Firstly, we apply a preprocessor to enhance the data quality by correcting spelling mistakes and removing noisy content. Secondly, our model utilizes CNN with max-pooling to extract contextual features and reduce feature dimensionality. Thirdly, two independent bidirectional RNN, i.e., Long Short-Term Memory and Gated Recurrent Unit are used to capture long-term dependencies. We also applied the attention mechanism to the RNN layer output to emphasize each word’s attention level. Furthermore, Gaussian Noise and Dropout as regularization are applied to avoid the overfitting problem. Finally, we verify the model’s robustness on four standard datasets. Compared with existing improvements on the most recent neural network models, the experiment results show that our model significantly outperformed the state-of-the-art models.

31 March 2020 in Peer-to-Peer Networking and Applications
Verified
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ZRZibin Ren
Zibin Ren
TLTing Lu
Ting Lu
XWXin Wang
Xin Wang
WGWenJing Guo
WenJing Guo
GLGuohua Liu
Guohua Liu
SCShan Chang
Shan Chang

4 August 2020 in Mobile Networks and Applications
Verified
Journal Article
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SAShanila Azhar
Shanila Azhar
SCShan Chang
Shan Chang
YLYe Liu
Ye Liu
YTYuting Tao
Yuting Tao
GLGuohua Liu
Guohua Liu

1 January 2021 in Computational Intelligence and Neuroscience
Verified
Journal Article
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MAMichael Adjeisah
Michael Adjeisah
GLGuohua Liu
Guohua Liu
DNDouglas Omwenga Nyabuga
Douglas Omwenga Nyabuga
RNRichard Nuetey Nortey
Richard Nuetey Nortey
JSJinling Song
Jinling Song
Scaling natural language processing (NLP) to low‐resourced languages to improve machine translation (MT) performance remains enigmatic. This research contributes to the domain on a low‐resource English‐Twi translation based on filtered synthetic‐parallel corpora. It is often perplexing to learn and understand what a good‐quality corpus looks like in low‐resource conditions, mainly where the target corpus is the only sample text of the parallel language. To improve the MT performance in such low‐resource language pairs, we propose to expand the training data by injecting synthetic‐parallel corpus obtained by translating a monolingual corpus from the target language based on bootstrapping with different parameter settings. Furthermore, we performed unsupervised measurements on each sentence pair engaging squared Mahalanobis distances, a filtering technique that predicts sentence parallelism. Additionally, we extensively use three different sentence‐level similarity metrics after round‐trip translation. Experimental results on a diverse amount of available parallel corpus demonstrate that injecting pseudoparallel corpus and extensive filtering with sentence‐level similarity metrics significantly improves the original out‐of‐the‐box MT systems for low‐resource language pairs. Compared with existing improvements on the same original framework under the same structure, our approach exhibits tremendous developments in BLEU and TER scores.

1 January 2021 in Computational Intelligence and Neuroscience
Verified
Journal Article
Open access
PDF file
DNDouglas Omwenga Nyabuga
Douglas Omwenga Nyabuga
JSJinling Song
Jinling Song
GLGuohua Liu
Guohua Liu
MAMichael Adjeisah
Michael Adjeisah
As one of the fast evolution of remote sensing and spectral imagery techniques, hyperspectral image (HSI) classification has attracted considerable attention in various fields, including land survey, resource monitoring, and among others. Nonetheless, due to a lack of distinctiveness in the hyperspectral pixels of separate classes, there is a recurrent inseparability obstacle in the primary space. Additionally, an open challenge stems from examining efficient techniques that can speedily classify and interpret the spectral‐spatial data bands within a more precise computational time. Hence, in this work, we propose a 3D‐2D convolutional neural network and transfer learning model where the early layers of the model exploit 3D convolutions to modeling spectral‐spatial information. On top of it are 2D convolutional layers to handle semantic abstraction mainly. Toward simplicity and a highly modularized network for image classification, we leverage the ResNeXt‐50 block for our model. Furthermore, improving the separability among classes and balance of the interclass and intraclass criteria, we engaged principal component analysis (PCA) for the best orthogonal vectors for representing information from HSIs before feeding to the network. The experimental result shows that our model can efficiently improve the hyperspectral imagery classification, including an instantaneous representation of the spectral‐spatial information. Our model evaluation on five publicly available hyperspectral datasets, Indian Pines (IP), Pavia University Scene (PU), Salinas Scene (SA), Botswana (BS), and Kennedy Space Center (KSC), was performed with a high classification accuracy of 99.85%, 99.98%, 100%, 99.82%, and 99.71%, respectively. Quantitative results demonstrated that it outperformed several state‐of‐the‐arts (SOTA), deep neural network‐based approaches, and standard classifiers. Thus, it has provided more insight into hyperspectral image classification.