Dongyu “Don” Han / Research engineer

A network is vast.
Our view is small.

A rapid valve closure launches a transient pressure wave through the pipes. We record the resulting pressure response at only a handful of sensors. My research asks what those signals can reveal about a leak—and where we should measure them.

A water network with eight sensor positions A simplified view of the Beacon Hill pipe branches. Eight yellow squares mark measurement locations along the network. INLETPIPE NETWORK
Eight measurement points.Each yellow square marks a pressure sensor.
HKUST MPhil · 2026Scroll to explore ↓

The challenge

The network is mapped.
The leak is not.

A leak can change how transient pressure waves reflect and scatter through the pipes. But labeled field measurements are scarce, and every additional sensor costs money and effort. That leads to two connected questions: how can a model learn from limited measured responses, and where should we place the sensors?

01 Learn across the gap

Start in simulation.
Test in the field.

We can simulate many leak scenarios, but collect only a small number of labeled transient pressure responses in the field. Simulations give a model a starting point; measured responses let us test and adapt it to the physical network.

I fine-tuned models trained on simulated transients using limited experimental measurements. I then used Integrated Gradients to inspect which sensor–time regions contributed most to their predictions.

Transfer learning · Interpretable leak diagnosis
Transient pressure responsesConceptual view
SimulatedHydraulic-model response
MeasuredIrregular response and measurement noise
Illustrative waveforms only—not recorded data, calibrated signals, or a matched simulation–measurement pair.
THE QUESTION

Can features learned from simulated transients still help when the model meets measured responses?

What changed

On the original experimental dataset, fine-tuning substantially reduced the best model’s leak-location error.

Best leak-location MAE

Transformer model · 17 experimental scenarios

13.51 m Direct simulation-to-field test1.02 m After field-data fine-tuning

Mean absolute error on this evaluation; lower is better. These are best-model results, not a general field-performance guarantee.

02 Choose where to measure

When you cannot
measure everywhere.

Even a strong model is limited by what its sensors record. In a larger network, adding sensors at every node is impractical; each location has to earn its place.

I built a method that learns which subset of locations is most useful for distinguishing leak events. The network below shows the branches and nodes; the changing selection probabilities show the model making that choice during training.

Contrastive learning · Sensor selection
Q-Leak networkBranches and nodes
Simplified Q-Leak network A minimal map of the Q-Leak outer run and intermediate loop, connected by a short pipe between them. Eighteen network nodes are shown without pipe-material or diameter details.
The short link joins the outer run to the intermediate loop. Each circle marks a modeled node, not an installed sensor.
Selection over trainingK = 5 · SNR = 0 dB
Heatmap showing how selection probabilities for Q-Leak sensor IDs evolve over training epochs, including warm-up, exploration and push stages.
As training progresses, the model gives some candidate locations a consistently higher chance of being selected.
What changed

Choosing sensors for the task—not just spreading them across the pipes—can improve what the model recognizes.

Classification accuracy

One simulated Q‑Leak setting · 8 sensors · SNR = 0 dB

%
Information-based selection (MI/MaxDet)
73.93
Task-aligned selection (DCSS)
86.62

At some lower-SNR, tighter-budget settings, the MI/MaxDet baseline performs better. This comparison uses simulated responses, not field measurements.

Publication

The work
behind the story.

The simulation-to-field study is published in Water Research. If you want the methods, assumptions, and full results, start here.

Water Research · 2026

Explainable simulation-to-field transfer learning for transient-based leak detection in water distribution networks

Dongyu Han, Oussama Choura, Muhammad Waqar, Moez Louati, Dai Linhan & Mohamed Salah Ghidaoui

Read the paper

Experience

From experiment
to implementation.

2026 — Present

IT Engineer · Algorithm Design

Hyele Limited · Hong Kong Science Park

Develop machine-learning algorithms for real-time pipeline condition assessment, from transient-signal processing and model validation to neural-network inference and sensor optimization.

2023 — 2026

MPhil Researcher · Applied AI for Smart Infrastructure

HKUST · Civil and Environmental Engineering

Built reproducible simulation-to-field experiments for leak diagnosis and a contrastive, differentiable framework for sparse sensor selection.

2022 — 2023

Backend Engineer · ML + Backend

Yuzhi Tech Co., Ltd. · Beijing

Built Java/Spring Boot services and integrated ML inference into a production digital-human system; contributed to a secondary-market knowledge graph project.

EducationMPhil, Civil & Environmental Engineering · HKUST, 2026
BEng, Computer Science & Technology · North China University of Technology, 2022

Independent project

EvidenceGraph.

A web app for exploring research papers. Upload a PDF, ask a question, inspect the source passages behind the answer, and browse the paper’s extracted relationships.

Explore EvidenceGraph
Inside a paperSources & connections
An illustrative evidence graph A paper connects to source passages. The passages connect to concepts and an answer, while a relationship connects the concepts. PDF A Paper Passage Passage Entity Entity Answer
Illustrative connections, not a graph from a specific paper.

What comes next

Let’s ask
better questions.

I’m interested in PhD opportunities around trustworthy machine learning, sensing, scientific ML, and intelligent infrastructure. If our questions overlap, I’d love to talk.