Guojun Mao

Dr. Guojun Mao


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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1 January 2021 in Complexity
Verified
Journal Article
Open access
PDF file
Xingsi XueXingsi Xue
Xingsi Xue
CYChaofan Yang
Chaofan Yang
CJChao Jiang
Chao Jiang
PTPei-Wei Tsai
Pei-Wei Tsai
GMGuojun Mao
Guojun Mao
HZHai Zhu
Hai Zhu
Data heterogeneity is the obstacle for the resource sharing on Semantic Web (SW), and ontology is regarded as a solution to this problem. However, since different ontologies are constructed and maintained independently, there also exists the heterogeneity problem between ontologies. Ontology matching is able to identify the semantic correspondences of entities in different ontologies, which is an effective method to address the ontology heterogeneity problem. Due to huge memory consumption and long runtime, the performance of the existing ontology matching techniques requires further improvement. In this work, an extended compact genetic algorithm‐based ontology entity matching technique (ECGA‐OEM) is proposed, which uses both the compact encoding mechanism and linkage learning approach to match the ontologies efficiently. Compact encoding mechanism does not need to store and maintain the whole population in the memory during the evolving process, and the utilization of linkage learning protects the chromosome’s building blocks, which is able to reduce the algorithm’s running time and ensure the alignment’s quality. In the experiment, ECGA‐OEM is compared with the participants of ontology alignment evaluation initiative (OAEI) and the state‐of‐the‐art ontology matching techniques, and the experimental results show that ECGA‐OEM is both effective and efficient.

6 November 2022 in Mathematics
Verified
Journal Article
Open access
PDF file
GMGuojun Mao
Guojun Mao
GLGuanyi Liao
Guanyi Liao
HZHengliang Zhu
Hengliang Zhu
BSBo Sun
Bo Sun
Recently, it has been demonstrated that the performance of an object detection network can be improved by embedding an attention module into it. In this work, we propose a lightweight and effective attention mechanism named multibranch attention (M3Att). For the input feature map, our M3Att first uses the grouped convolutional layer with a pyramid structure for feature extraction, and then calculates channel attention and spatial attention simultaneously and fuses them to obtain more complementary features. It is a “plug and play” module that can be easily added to the object detection network and significantly improves the performance of the object detection network with a small increase in parameters. We demonstrate the effectiveness of M3Att on various challenging object detection tasks, including PASCAL VOC2007, PASCAL VOC2012, KITTI, and Zhanjiang Underwater Robot Competition. The experimental results show that this method dramatically improves the object detection effect, especially for the PASCAL VOC2007, and the mapping index of the original network increased by 4.93% when embedded in the YOLOV4 (You Only Look Once v4) network.

21 February 2020 in Sensors
Verified
Journal Article
Open access
PDF file
BXBaoping Xiong
Baoping Xiong
Nianyin ZengNianyin Zeng
Nianyin Zeng
LYLi Yurong
Li Yurong
MDMin Du
Min Du
MHMeilan Huang
Meilan Huang
YYYuan Yang
Yuan Yang
Introduction: Human joint moment is a critical parameter to rehabilitation assessment and human-robot interaction, which can be predicted using an artificial neural network (ANN) model. However, challenge remains as lack of an effective approach to determining the input variables for the ANN model in joint moment prediction, which determines the number of input sensors and the complexity of prediction. Methods: To address this research gap, this study develops a mathematical model based on the Hill muscle model to determining the online input variables of the ANN for the prediction of joint moments. In this method, the muscle activation, muscle-tendon moment velocity and length in the Hill muscle model and muscle-tendon moment arm are translated to the online measurable variables, i.e., muscle electromyography (EMG), joint angles and angular velocities of the muscle span. To test the predictive ability of these input variables, an ANN model is designed and trained to predict joint moments. The ANN model with the online measurable input variables is tested on the experimental data collected from ten healthy subjects running with the speeds of 2, 3, 4 and 5 m/s on a treadmill. The variance accounted for (VAF) between the predicted and inverse dynamics moment is used to evaluate the prediction accuracy. Results: The results suggested that the method can predict joint moments with a higher accuracy (mean VAF = 89.67±5.56 %) than those obtained by using other joint angles and angular velocities as inputs (mean VAF = 86.27±6.6%) evaluated by jack-knife cross-validation. Conclusions: The proposed method provides us with a powerful tool to predict joint moment based on online measurable variables, which establishes the theoretical basis for optimizing the input sensors and detection complexity of the prediction system. It may facilitate the research on exoskeleton robot control and real-time gait analysis in motor rehabilitation.

4 April 2024 in IEEE Transactions on Instrumentation and Measurement
Verified
Journal Article
Closed access
BXBaoping Xiong
Baoping Xiong
YCYiran Chang
Yiran Chang
Nianyin ZengNianyin Zeng
Nianyin Zeng
YNYinxi Niu
Yinxi Niu
HZHui Zeng
Hui Zeng
YXYong Xu
Yong Xu
Estimating joint moment using surface electromyography (sEMG) signals is vital in industrial and rehabilitation area. Current prediction methods mostly focused on extracting single-scale temporal features. However, the spatial information between channels is also essential in joint moment estimation. Therefore, we introduced a trans-scale hybrid (TranSEMG) model that has two streams. The spatial-feature-net module was designed for one stream, which can extract the spatial features according to different effects of muscles corresponding to different channels on joint moment. Another stream used the temporal convolutional network (TCN) module to learn temporal features. Then, we utilized the designed fusion module (FM) for temporal and spatial features fusion. The model was tested on experimental data collected from nine healthy subjects walking on treadmill, level ground, and ramp. The root-mean-square error (RMSE), the coefficient of determination (R2), and variance accounted for (VAF) between the predicted and inverse dynamics moment are used to evaluate the prediction accuracy. Compared with the state-of-the-art models, the trans-scale hybrid model can predict joint moments with lower RMSE, higher R2, and higher VAF values. Furthermore, the model also has good versatility and showed good performance in other walking environments, such as ramp and level ground. In conclusion, this study provided a new model to get more features from sequences to predict the hip joint moment and achieved a good prediction accuracy.

6 November 2023 in Engineering Applications of Artificial Intelligence
Verified
Journal Article
Closed access
XWXingzhen Wu
Xingzhen Wu
GMGuojun Mao
Guojun Mao
XSXing Shuli
Xing Shuli

28 February 2025 in IEEE Transactions on Intelligent Transportation Systems
Verified
Journal Article
Closed access
Xingsi XueXingsi Xue
Xingsi Xue
GMGuojun Mao
Guojun Mao
SKSaru Kumari
Saru Kumari
ZLZhonghua Liu
Zhonghua Liu
Transportation Networks (TNs) play a critical role in economic and social systems, yet the dynamic nature and inherent heterogeneity of TN data pose challenges for Dynamic Knowledge Integration (DKI). Traditional approaches for matching entities from different knowledge bases often struggle with the complexity and diversity of TN data, which varies across systems and sources such as traffic sensors and GPS devices. To address this issue, this paper proposes a novel Multi-Objective Genetic Programming assisted Stochastic Deep Reinforcement Learning (MOGP-SDRL) for DKI in TNs. Unlike existing methods, the proposed framework combines SDRL and MOGP to achieve superior efficiency, accuracy and adaptability in handling heterogeneous TN data. First, a novel SDRL framework is designed to automate and optimize the selection of Similarity Features (SFs) for entity matching. This framework incorporates a probabilistic action selection mechanism, which enhances exploration during the SF selection process. Second, a novel MOGP is presented to construct high-quality, diverse SFs by exploring non-dominated feature ensembles, enhancing both accuracy and adaptability in matching results, leading to more accurate and adaptable matching results compared to conventional methods. Lastly, new approximate evaluation metrics are developed to assess alignment quality without relying on predefined entity alignments, guiding the optimization process. Experimental evaluations on OAEI’s knowledge graph (KG) dataset and five pairs of real-world TN dataset demonstrate the effectiveness of the MOGP-SDRL framework, which consistently produces high-quality matching results and achieves significant improvements in both accuracy and robustness over existing approaches.