Solving real-world problems with AI.

I’m an Applied AI Scientist with a PhD and industry experience. I build practical, reliable AI solutions, from early prototypes to real-world deployment.

NowData Scientist at Dragonfly Data Science

Portrait of Zoey Sun smiling, standing among native bush
Zoey (Ziyi) Sun

Ask about my work

An assistant that answers from my CV, projects and publications. It’s quicker than reading everything — but answers can be imperfect, so follow the source links.

Profile Q&A

Prepared answers from Zoey’s profile and publications.

Selected work

An aerial image beside the model-predicted synthetic canopy height model for the same area

01Dragonfly Data Science2025 – now

Dynamic forest mapping

Predicting canopy height from aerial imagery, trained and validated against LiDAR, so forest structure can be mapped wherever LiDAR doesn’t reach.

Part of a New Zealand–NASA research partnership with NASA Earth Exchange

  • Machine learning
  • Remote sensing
  • LiDAR
  • U-Net
The same aerial image with every detected tree crown outlined and filled in red, each labelled with a confidence score Input Prediction

02PhD research2021 – 2025

Finding every tree

New YOLO and Mask R-CNN variants that detect and outline individual tree crowns in aerial imagery — even where canopies overlap. Drag the image to compare input and prediction.

+10% detection and +8% segmentation accuracy · six papers

  • PyTorch
  • YOLO
  • Transformers
  • Instance segmentation
Concept diagram: government and research sources feed a retrieval step, which grounds a conversational answer with citations gov services NZ research retrieve cited answer

03Callaghan Innovation2024 – 2025

GovGPT & PaperBoi

Retrieval-augmented assistants that help New Zealanders find government services and policy in plain language, and explore research from New Zealand institutions.

  • Python
  • RAG
  • Azure AI Studio
  • AWS
Concept diagram: an AI draft is evaluated, reviewed by a person, then delivered, with a loop back for revisions AI draft evaluate human review deliver revise

04ElementX2025

LLM evaluation & document automation

Structured testing of chatbot answers, plus n8n workflows that draft proposals with AI and route every draft through human review before it’s sent.

  • LLMs
  • SQL
  • Ruby
  • n8n
A steel wheel hub on an inspection table, with the detected weld seam marked by a blue bounding box Glassware with an inset close-up of a detected bubble, confidence 0.93 Weld seam Glass flaw

05Applied AI, China2020 – 2021

Industrial visual inspection

YOLO detectors that locate weld seams on wheel hubs and find flaws in glass — taken from raw factory images to client deployment.

99.98% detection · under 0.3 cm positioning error

  • Computer vision
  • YOLO
  • Dataset building
Illustration of dehazing: a hazy mountain valley on the left and the same kind of scene, clear, on the right

06Master’s research2018 – 2021

Single-image dehazing

Attention-based and CycleGAN methods that recover colour, contrast and fine texture from a single hazy photograph.

Published in ACM TOMM and Computer Vision and Image Understanding

  • Deep learning
  • Attention
  • CycleGAN

Where I’ve worked

  1. Nov 2025 — PresentWellington

    Data Scientist

    Dragonfly Data Science

    Machine learning for forest mapping from aerial imagery and LiDAR, as part of a New Zealand–NASA research partnership.

  2. Aug — Oct 2025Auckland

    R&D Intern

    ElementX

    Chatbot backends, structured LLM response evaluation and n8n document automation.

  3. Mar — Aug 2025Wellington

    Research Assistant

    Victoria University of Wellington

    Extended my tree-crown instance segmentation research with Manaaki Whenua – Landcare Research.

  4. Oct 2024 — Mar 2025Wellington

    Digital & AI Intern

    Callaghan Innovation

    Improved RAG and semantic retrieval for the GovGPT and PaperBoi assistants.

  5. Oct 2021 — Feb 2025Wellington

    PhD Researcher

    Victoria University of Wellington

    Detection and instance segmentation of tree crowns in aerial imagery, with large-scale data pipelines and multi-GPU training.

Publications

Published as Ziyi Sun. Most of my work asks how to make detection and segmentation models hold up on messy, real-world imagery.

8
papers
7
first-author

Tree crowns & remote sensing

  1. 2026

    YOLO-ITC: A New YOLO Method for Instance Segmentation of Individual Tree Crowns

    Ziyi Sun, Bing Xue, Mengjie Zhang, Jan Schindler

    IEEE Transactions on Emerging Topics in Computational Intelligence 10(1), 51–65 · early access 2025

  2. 2026

    YOLOv8-UT: A Unified Training Approach for Cross-Environment Tree Crown Instance Segmentation in Aerial Imagery

    Ziyi Sun, Bing Xue, Mengjie Zhang, Jan Schindler

    PRICAI 2025: Trends in Artificial Intelligence LNCS 16455, 298–314 · Springer

  3. 2025

    Feature Fusion to Improve YOLOv8 for Segmenting and Classifying Aerial Images of Tree Crowns

    Ziyi Sun, Bing Xue, Mengjie Zhang, Jan Schindler

    IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 18, 14752–14765

  4. 2025

    YOLOv8E: An Efficient YOLOv8 Method for Instance Segmentation of Individual Tree Crowns in Wellington City, New Zealand

    Ziyi Sun, Bing Xue, Mengjie Zhang, Jan Schindler

    Journal of the Royal Society of New Zealand 55(6), 1854–1879

  5. 2025

    Efficient Tree Mapping through Deep Distance Transform (DDT) Learning

    Jan Schindler, Ziyi Sun, Bing Xue, Mengjie Zhang

    ISPRS Open Journal of Photogrammetry and Remote Sensing 17, 100095

  6. 2023

    An Improved Mask R-CNN for Instance Segmentation of Tree Crowns in Aerial Imagery

    Ziyi Sun, Bing Xue, Mengjie Zhang, Jan Schindler

    38th International Conference on Image and Vision Computing New Zealand (IVCNZ) 1–6

Image dehazing

  1. 2022

    SADnet: Semi-supervised Single Image Dehazing Method Based on an Attention Mechanism

    Ziyi Sun, Yunfeng Zhang, Fangxun Bao, Ping Wang, Xunxiang Yao, Caiming Zhang

    ACM Transactions on Multimedia Computing, Communications, and Applications 18(2), article 58, 1–23

  2. 2021

    ICycleGAN: Single Image Dehazing Based on Iterative Dehazing Model and CycleGAN

    Ziyi Sun, Yunfeng Zhang, Fangxun Bao, Kai Shao, Xinxin Liu, Caiming Zhang

    Computer Vision and Image Understanding 203, 103133

What I work with

Code & data
Python, SQL, Java, C/C++, LaTeX, Pandas, NumPy, SciPy
Machine learning
PyTorch, TensorFlow, scikit-learn, OpenCV, CNNs, Transformers, U-Net, YOLO
Remote sensing
Aerial imagery, LiDAR, canopy height prediction, tree-crown segmentation, geospatial datasets
Generative AI
LLM applications, RAG, semantic retrieval, LLM evaluation, n8n automation
MLOps & cloud
Git, GitHub, CI, reproducible pipelines, multi-GPU training, Azure AI Studio, AWS, Linux
Analysis & reporting
Statistical analysis, experimental evaluation, Power BI, Matplotlib, Seaborn
AI-assisted development
Codex, ChatGPT, Claude Code, Gemini
Communication
Papers, conference talks, technical reports, workshops, client demos, AI/ML tutoring

Where I studied

  1. PhD

    Artificial Intelligence

    Victoria University of Wellington

    2021 — 2025
  2. M.S.

    Computer Application Technology

    Shandong University of Finance and Economics

    2018 — 2021
  3. B.S.

    Digital Media Technology

    Shandong University of Finance and Economics

    2014 — 2018

Contact

Let’s talk.

Research collaborations, applied-AI questions or a dataset that needs a closer look — I’d be glad to hear from you.

Case study

Case study