Hengxi Liu

Mr. Hengxi Liu

College of Geoexploration Science and Technology, Jilin University, Changchun, Jilin, China
orcid

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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12 July 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Muhammad Atif BilalMuhammad Atif Bilal
Muhammad Atif Bilal
Yongzhi WangYongzhi Wang
Yongzhi Wang
YJYanju Ji
Yanju Ji
MAMuhammad Pervez Akhter
Muhammad Pervez Akhter
HLHengxi Liu
Hengxi Liu
Earthquakes threaten people, homes, and infrastructure. Earthquake detection is a complex task because it does not show any specific pattern, unlike object detection from images. Convolutional neural networks have been widely used for earthquake detection but have problems like vanishing gradients, exploding, and parameter optimization. The ensemble learning approach combines multiple models, each of which attempts to compensate for the shortcomings of the others to enhance performance. This article proposes an ensemble learning model based on a stacked normalized recurrent neural network (SNRNN) for earthquake detection. The proposed model uses three recurrent neural network models (RNN, GRU, and LSTM) with batch normalization and layer normalization. After preprocessing the waveform data, the RNN, GRU, and LSTM extract the feature map sequentially. Batch normalization and layer normalization methods take place in mini-batches and input layers for stable and faster training of the model and improving its performance. We trained and tested the proposed model on 6574 events from 2000 to 2018 (18 years) in Turkey, a highly targeted region. The SNRNN achieves RMSE values of 3.16 and 3.24 for magnitude and depth detection. The SNRNN model outperforms the three baseline models, as seen by their low RMSE values.

29 September 2024 in Remote Sensing
Verified
Journal Article
Open access
PDF file
SWShibo Wen
Shibo Wen
Yongzhi WangYongzhi Wang
Yongzhi Wang
QGQizhou Gong
Qizhou Gong
JLJianzhong Liu
Jianzhong Liu
KXKang Xiao,Xi
Kang Xiao,Xi
SZSheng Zhang
Sheng Zhang
The safety of lunar landing sites directly impacts the success of lunar exploration missions. This study develops a data-driven predictive model based on machine learning, focusing on engineering safety to assess the suitability of lunar landing sites and provide insights into key factors and feature representations. Six critical engineering factors were selected as constraints for evaluation: slope, elevation, roughness, hillshade, optical maturity, and rock abundance. The XGBoost model was employed to simulate and predict the characteristics of landing areas and Bayesian optimization was used to fine-tune the model’s key hyperparameters, enhancing its predictive performance. The results demonstrate that this method effectively extracts relevant features from multi-source remote sensing data and quantifies the suitability of landing zones, achieving an accuracy of 96% in identifying landing sites (at a resolution of 0.1° × 0.1°), with AUC values exceeding 95%. Notably, slope was recognized as the most critical factor affecting safety. Compared to assessment processes based on Convolutional Neural Networks (CNNs) and Random Forest (RF) models, XGBoost showed superior performance in handling missing values and evaluating feature importance accuracy. The findings suggest that the BO-XGBoost model shows notable classification performance in evaluating the suitability of lunar landing sites, which may provide valuable support for future landing missions and contribute to optimizing lunar exploration efforts.

27 February 2024 in Atmosphere
Verified
Journal Article
Open access
PDF file
SWShibo Wen
Shibo Wen
Yongzhi WangYongzhi Wang
Yongzhi Wang
HSHaohang Song
Haohang Song
HLHengxi Liu
Hengxi Liu
ZSZhaolong Sun
Zhaolong Sun
Muhammad Atif BilalMuhammad Atif Bilal
Muhammad Atif Bilal
The external environment in the transitional zone of the ecological barrier is fragile, and economic growth has resulted in a series of land degradation issues, significantly impacting regional economic development and the ecological environment. Therefore, monitoring, assessing, and predicting land use changes are crucial for ecological security and sustainable development. This study developed an integrated model comprising convolutional neural network, cellular automata, and Markov chain to forecast the land use status of western Jilin, located in the transitional zone of the ecological barrier, by the year 2030. Additionally, the study evaluated the role of land use policies in the context of land use changes in western Jilin. The findings demonstrate that the coupled modeling approach exhibits excellent predictive performance for land use prediction in western Jilin, yielding a Kappa coefficient of 93.26%. Policy drivers play a significant role in shaping land use patterns in western Jilin, as evidenced by the declining farmland accompanied by improved land utilization, the sustained high levels of forest aligning with sustainable development strategies, the ongoing restoration of waters and grassland, which are expected to show positive growth by 2030, and the steady growth in built-up areas. This study contributes to understanding the dynamics of land use in the transitional zone of the ecological barrier, thereby promoting sustainable development and ecological resilience in the region.

29 April 2025 in Remote Sensing
Verified
Journal Article
Open access
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HLHengxi Liu
Hengxi Liu
Yongzhi WangYongzhi Wang
Yongzhi Wang
SWShibo Wen
Shibo Wen
SZSheng Zhang
Sheng Zhang
KZKai Zhu
Kai Zhu
JLJianzhong Liu
Jianzhong Liu
The permanently shadowed regions of the lunar South Pole have become a key target for international lunar exploration due to their unique scientific value and engineering challenges. In order to effectively screen suitable landing zones near the lunar South Pole, this research proposes a comprehensive evaluation method based on a self-organizing map (SOM). Using multi-source remote sensing data, the method classifies and analyzes candidate landing zones by combining scientific purposes (such as hydrogen abundance, iron oxide abundance, gravity anomalies, water ice distance analysis, and geological features) and engineering constraints (such as Sun visibility, Earth visibility, slope, and roughness). Through automatic clustering, the SOM model finds the important regions. Subsequently, it integrates with a supervised learning model, a random forest, to determine the feature importance weights in more detail. The results from the research indicate the following: the areas suitable for landing account for 9.05%, 5.95%, and 5.08% in the engineering, scientific, and synthesized perspectives, respectively. In the weighting analysis of the comprehensive data, the weights of Earth visibility, hydrogen abundance, kilometer-scale roughness, and slope data all account for more than 10%, and these are thought to be the four most important factors in the automated site selection process. Furthermore, the kilometer-scale roughness data are more important in the comprehensive weighting, which is in line with the finding that the kilometer-scale roughness data represent both surface roughness from an engineering perspective and bedrock geology from a scientific one. In this study, a local examination of typical impact craters is performed, and it is confirmed that all 10 possible landing sites suggested by earlier authors are within the appropriate landing range. The findings demonstrate that the SOM-model-based analysis approach can successfully assess lunar South Pole landing areas while taking multiple constraints into account, uncovering spatial distribution features of the region, and offering a rationale for choosing desired landing locations.

19 June 2023 in Remote Sensing
Verified
Journal Article
Open access
PDF file
HLHengxi Liu
Hengxi Liu
Yongzhi WangYongzhi Wang
Yongzhi Wang
SWSHIBO WEN
SHIBO WEN
JLJianzhong Liu
Jianzhong Liu
JWJiaxiang Wang
Jiaxiang Wang
Yuanzhi ZhangYuanzhi Zhang
Yuanzhi Zhang
Deep space exploration has risen in interest among scientists in recent years, with soft landings being one of the most straightforward ways to acquire knowledge about the Moon. In general, landing mission success depends on the selection of landing zones, and there are currently few effective quantitative models that can be used to select suitable landing zones. When automatic landing zones are selected, the grid method used for data partitioning tends to miss potentially suitable landing sites between grids. Therefore, this study proposes a new engineering-constrained approach for landing zone selection using LRO LOLA-based slope data as original data based on the sliding window method, which solves the spatial omission problem of the grid method. Using the threshold ratio, mean, coefficient of variation, Moran’s I, and overall rating, this method quantifies the suitability of each sliding window. The k-means clustering algorithm is adopted to determine the suitability threshold for the overall rating. The results show that 20 of 22 lunar soft landing sites are suitable for landing. Additionally, 43 of 50 landing sites preselected by the experts (suitable landing sites considering a combination of conditions) are suitable for landing, accounting for 90.9% and 86% of the total number, respectively, for a window size of 0.5° × 0.5°. Among them, there are four soft landing sites: Surveyor 3, 6, 7, and Apollo 15, which are not suitable for landing in the evaluation results of the grid method. However, they are suitable for landing in the overall evaluation results of the sliding window method, which significantly reduces the spatial omission problem of the grid method. In addition, four candidate landing regions, including Aristarchus Crater, Marius Hills, Moscoviense Basin, and Orientale Basin, were evaluated for landing suitability using the sliding window method. The suitability of the landing area within the candidate range of small window sizes was 0.90, 0.97, 0.49, and 0.55. This indicates the capacity of the method to analyze an arbitrary range during blind landing zone selection. The results can quantify the slope suitability of the landing zones from an engineering perspective and provide different landing window options. The proposed method for selecting lunar landing zones is clearly superior to the gridding method. It enhances data processing for automatic lunar landing zone selection and progresses the selection process from qualitative to quantitative.

14 March 2024 in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Verified
Journal Article
Open access
TTTianqi Tang
Tianqi Tang
RQRuiqing Qie
Ruiqing Qie
Zhiguo MengZhiguo Meng
Zhiguo Meng
HLHengxi Liu
Hengxi Liu
ZWZhaoran Wei
Zhaoran Wei
Evaluating the complex surface deposits of the Schiller-Schickard cryptomare region can enhance our understanding of basaltic volcanic activity and lunar surface evolution. This study utilizes brightness temperature (TB), normalized TB (nTB), and TB difference (dTB) maps generated from the Chang'E (CE)-2 microwave radiometer (MRM) data. The S-S region's surface deposits were also evaluated by combining the datasets from the Lunar Prospector Thorium, Diviner, LOLA, Clementine UV-VIS, Bouguer Gravity, and Lunar Reconnaissance Orbiter Wide Angle Camera. The main research findings are as follows: (1) Based on the TB distribution characteristics of craters, four types of craters are identified in the S-S region. The microwave radiation TB of each type of crater is affected by varying degree of influencing factors. (2) According to the nTB and dTB performances, combined with the distribution of surface compositions and high-density materials, the extent of Mare-like Cryptomare Deposits (MCD) is considered more reasonable. It is speculated that there are at least two different periods of buried mare deposits eruptions in Region MCD. (3) Within Region MCD, two patches with low TB anomaly are discovered. These discoveries advance our knowledge of the Moon's surface evolution.