Haoyu Wang

Mr. Haoyu Wang

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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9 January 2025 in Advances in Meteorology
Verified
Journal Article
Open access
PMPing Mei
Ping Mei
ZYZixin Yin
Zixin Yin
HWHaoyu Wang
Haoyu Wang
CLChangzheng Liu
Changzheng Liu
YLYaoming Liao
Yaoming Liao
LYLiping Yin
Liping Yin
Machine learning has achieved significant success in many statistical application scenarios, but has yet to be fully successful in monthly and seasonal predictions. We identified three statistical challenges in climate prediction: instability of statistical models, complexity of feature factors, and the nonlinearity of the relationship between predictors and predictands. These characteristics limit both traditional empirical forecasting and machine learning methods. This paper proposes a novel method called dynamically modeled machine learning to predict monthly temperature anomalies over China. The core idea of dynamic modeling is that the machine learning model is trained using a sliding time window, so that the relationship between predictors and predictands is optimized for a specific and recent period rather than for the entire time span. One hundred thirty indices related to atmospheric and oceanic circulation and other climatic events from the Beijing Climate Center are used as the feature set. After feature engineering, including feature selection and dimensionality reduction, the predictors are generated and input into a regressor. Five machine learning algorithms are employed as regressors one by one: linear regression (LR), ridge regression (RR), random forest (RF), support vector machine (SVM), and gradient boosting decision trees (GBDTs). The method performs reforecasting for 2012–2021 and compares the results with the output of operational climate models from ECMWF, NCEP, and the Beijing Climate Center. Three quantitative evaluation metrics—predictive score (PS), anomaly correlation coefficient (ACC), and anomaly sign agreement rate—were used to assess the prediction performance of each machine learning regressor, the ensemble model, and three dynamic models. The results demonstrate that the method using GBDTs as the regressor achieves the best predictive performance compared to other methods and operational models, with a monthly average PS score of 84, an ACC value of 0.27, and an anomaly sign agreement rate of 74%.

22 July 2024 in Mathematics
Verified
Journal Article
Open access
PDF file
HWHaoyu Wang
Haoyu Wang
XWXiaoyuan Wan
Xiaoyuan Wan
JHJunyao Hou
Junyao Hou
JLJing Lian
Jing Lian
YWYuzhao Wang
Yuzhao Wang
The species of the adaptive male–female sex ratio has different effects on the bio-community. This paper is aimed at figuring out these effects through mechanism analysis and Ordinary Differential Equation (ODE). Hence, the ODE environmental model is created by combining the Lotka–Volterra model, the interspecific model, and other external factors. The stability is used to characterize these effects. According to this model, effects on bio-community stability under different male–female sex ratios are roughly observed. By innovatively considering different living environments during the species’ lifecycle, the ODE environmental model is optimized, and the effects of different male–female sex ratios on the bio-community are further analyzed by phase-track maps and relative standard deviation. It is found that there are different findings and features in resource-rich and resource-scarce living environments during the lifecycle. Meanwhile, bio-communities in these two types of environments are in a stable state based on different male–female sex ratios. Based on these findings, directive opinions can be used to manage and help relevant bio-communities.