Chen Yajun

Mr. Chen Yajun


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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31 October 2023 in Sensors
Verified
Journal Article
Open access
PDF file
CCChen Cai
Chen Cai
AQAgen Qiu
Agen Qiu
HCHaoyu Chen
Haoyu Chen
CYChen Yajun
Chen Yajun
XLXu Liu
Xu Liu
Dong LiDong Li
Dong Li
Accurate and reliable prediction of air pollutant concentrations is important for rational avoidance of air pollution events and government policy responses. However, due to the mobility and dynamics of pollution sources, meteorological conditions, and transformation processes, pollutant concentration predictions are characterized by great uncertainty and instability, making it difficult for existing prediction models to effectively extract spatial and temporal correlations. In this paper, a powerful pollutant prediction model (STA-ResConvLSTM) is proposed to achieve accurate prediction of pollutant concentrations. The model consists of a deep learning network model based on a residual neural network (ResNet), a spatial–temporal attention mechanism, and a convolutional long short-term memory neural network (ConvLSTM). The spatial–temporal attention mechanism is embedded in each residual unit of the ResNet to form a new residual neural network with the spatial–temporal attention mechanism (STA-ResNet). Deep extraction of spatial–temporal distribution features of pollutant concentrations and meteorological data from several cities is carried out using STA-ResNet. Its output is used as an input to the ConvLSTM, which is further analyzed to extract preliminary spatial–temporal distribution features extracted from the STA-ResNet. The model realizes the spatial–temporal correlation of the extracted feature sequences to accurately predict pollutant concentrations in the future. In addition, experimental studies on urban agglomerations around Long Beijing show that the prediction model outperforms various popular baseline models in terms of accuracy and stability. For the single-step prediction task, the proposed pollutant concentration prediction model performs well, exhibiting a root-mean-square error (RMSE) of 9.82. Furthermore, even for the pollutant prediction task of 1 to 48 h, we performed a multi-step prediction and achieved a satisfactory performance, being able to achieve an average RMSE value of 13.49.

18 November 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
AQAgen Qiu
Agen Qiu
QWQinglian Wang
Qinglian Wang
CYChen Yajun
Chen Yajun
KTKunwang Tao
Kunwang Tao
XPXiang Yu Peng
Xiang Yu Peng
FZFuhao Zhang
Fuhao Zhang
Landslide susceptibility is crucial for assessing the probability and severity of landslide disasters in a region. Previous studies have focused on static landslide susceptibility, using landslide assessment factor data from varying years, making it difficult to estimate spatio-temporal consistency and resulting in low prediction accuracy. Taking Hong Kong, China, as the study region, this study proposes a framework to estimate spatio-temporally consistent landslide susceptibility. The landslide assessment factors are divided into static and dynamic factors, with a temporal resolution of 5 years. Specifically, the dynamic assessment of landslide susceptibility is conducted for the periods 2000–2004, 2005–2009, 2010–2014, and 2015–2019, covering a total span from 2000 to 2019. Results show that the accuracy of the proposed model, defined as the proportion of correctly classified samples relative to the total number of samples, exceeds 0.7 across these four time periods. Both the F1-Score and the receiver operating characteristic (ROC) curve indicate that the proposed research framework exhibits good accuracy and practicality in susceptibility assessment. The proposed framework could capture temporal variations in landslide occurrence, allowing for a more accurate prediction of landslide susceptibility. The findings provide valuable insights for landslide disaster prevention and mitigation in Hong Kong and would also be applicable in other countries or regions.