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Qiangqiang Mao

A PhD student at University of British Columbia.

I am passionate about applying interpretable machine learning to solve real-world decision support problems, and am actively looking for research/job opportunities in both fundamental and applied machine learning.

Bio Sketch

I am currently pursuing a Ph.D. degree at the University of British Columbia in Vancouver, Canada. Prior to this, I received my bachelor’s and master’s degrees from China University of Petroleum in Qingdao, China, in 2019 and 2022.

My research focuses on machine learning optimization (differentiable decision tree optimization) and its decision support applications in both traditional and renewable energy systems, including biomass, petroleum, battery, and hydrogen. I mainly develop a set of tree-based algorithms (decision tree, random forest and reinforcement learning with decision tree policy) and address the following four questions, especially for real-world industrial applications: (1) Can a single tree outperform an entire forest? (2) Do we really need hundreds of machine learning models for tabular data-driven applications? (3) Do we have to rely on heavy black-box convolutional neural networks for image classification? (4) Can reinforcement learning and learning-based control be interpretable as decision tree?


Recent News


Research Highlights

Fundamental Machine Learning

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NeurIPS 2025

Differentiable Decision Tree via "ReLU+Argmin" Reformulation

Mao Q., Ren J., Wang Y., Zou C., Zheng J., and Cao Y.

Advances in Neural Information Processing Systems 2025. Spotlight Paper.

This study proposes RADDT, a novel differentiable decision tree to address two key challenges: high accuracy and differentiability. Its enables large-scale, gradient-based optimization, making it effective even for million-scale datasets through distributed multi-GPUs acceleration.

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Can a Single Tree Outperform an Entire Forest?

Mao Q. and Cao Y.

arXiv:2411.17003. 2024

This study, GET, significantly improves decision tree's accuracy by unconstrained tree reformulation and increasingly-accurate soft approximation.

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A GPU-Accelerated Moving-Horizon Algorithm for Training Deep Classification Trees on Large Datasets

Ren J., Osuna V., Okamoto M., Mao Q., Cao L., Hua K., and Cao Y.

arXiv:2311.06952. 2023.

Decision Support

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A Decision Support Engine for Infill Drilling Attractiveness Evaluation Using Rule-based Cognitive Computing Under Expert Uncertainties

Mao Q., Ma X., and Wang Y.

Journal of Petroleum Science and Engineering. 2022.

This study developes a rules set-based reasoning engine for drilling target recommendation and well placement optimization.

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SPE ATCE 2025

Do We Really Need Hundreds of Machine Learning Models in Industry?

Mao Q., Yang X., Yang J. and Cao Y.

SPE Annual Technical Conference and Exhibition. 2025.

This study challenges recent practice in tabular data-driven petroleum applications by proposing a decision tree-based paradigm with 26 applications. It emphasizes practical field demands of accuracy, interpretability and lightweight structure.

Process Monitoring & Fault Detection

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Visual Process Monitoring of Biomass Conversion Reactors Using Transfer Learning and Generative AI.

Mao Q., Yip B., Xu C., Garg S., Guo P. and Cao Y.

Computer and Chemical Engineering. 2025.

This study proposes a GenAI-based data augmentation and tailored transfer learning strategy to address data scarcity, specifically for the faulty smoke events during biomass-to-biochar conversion processes.

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SPE ATCE 2025

Stop Using CNN: Knowledge Distillation for An Interpretable and Lightweight Decision Tree in Rod Pump Working Condition Diagnosis

Mao Q., Yang X., Yang J. and Cao Y.

SPE Annual Technical Conference and Exhibition. 2025.

This study challenges recent reliance on black-box, heavy models in dynamometer card-based fault diagnosis by proposing an interpretable and lightweight decision tree alternative. The proposed paradigm is also applied to other image classification tasks.

Control

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Exact Learning of Model Predictive Control Laws Using Oblique Decision Trees with Linear Predictions

Ren J., Mao Q., Zhao T. and Cao Y.

IEEE Conference on Decision and Control. 2025.

This study presents a successful application of our proposed differentiable decision tree (tree with linear predictions) in explicit model predictive control.

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Deep Learning-based Approximation of Model Predictive Control Laws Using Mixture Networks

Okamoto M., Ren J., Mao Q., Liu J. and Cao Y.

IEEE Transactions on Automation Science and Engineering. 2025.

This study addresses a major limitation of one-to-many mappings in deep learning-based model predictive control.

Contact Me

  • maoq@student.ubc.ca
  • 2360 East Mall
    Vancouver, BC, Canada, V6T 1Z3