Portrait of Xue-Cheng Tai

Chief Scientist · NORCE Norwegian Research Centre

Xue-Cheng Tai

I build the mathematics that makes heavy computation fast enough to use — in imaging, simulation and industrial data.

Bergen, Norway xtai@norceresearch.no +47 56 10 78 30 SIAM Fellow, 2026

What I work on

Four kinds of problem I am usually brought in to solve

Most industrial questions I see reduce to one of these. If yours looks like any of them, a short conversation is usually enough to tell whether the maths can help.

Sheet of MRI brain slices on a light box

Seeing what the sensor cannot show

Denoising, sharpening, segmentation and 3D reconstruction of images and scans — including cases with heavy noise, missing data or only a single projection. Methods that mark out an object and measure it reliably, not just make the picture look better.

Medical scans · inspection · microscopy · remote sensing
Steeply tilted layers of sedimentary rock

Inferring what you cannot measure directly

Inverse problems: recovering material properties, sources, permeabilities or geometry from indirect measurements, with methods that hold up when the answer is discontinuous and the data are incomplete.

Subsurface · process monitoring · non-destructive testing
Rendered swirl of blue and orange fluid flow

Simulation that runs in minutes, not days

Fast solvers for partial differential equations — splitting, multigrid and domain decomposition — plus physics-informed neural networks used as surrogates when the full simulation is too slow for the decision you need to make.

Flow · furnaces · blood flow · design optimisation
Blackboard densely covered in mathematical derivations

Machine learning you can explain

Deep networks that come with a mathematical account of why they work, and where you can build physical constraints and known geometry directly into the architecture. Useful when a black-box model is not acceptable to a regulator or a customer.

Certification · safety-critical AI · scarce training data

Track record

Algorithms that left the paper and went into use

Additive Operator Splitting (AOS)

A co-invented scheme that turns a stiff nonlinear image-processing problem into independent one-dimensional pieces. Fast, stable, easy to parallelise — now standard in PDE-based image processing.

Split Bregman

Developed by Stanley Osher (UCLA) and co-authors which is based an earlier method developed by Lysaker_Osher_Tai. One of the most widely used ways to solve total-variation and sparse-recovery problems; the backbone of many practical reconstruction pipelines.

Piecewise Constant Level Set Method

Represents several regions or materials with a single function, which makes multi-phase segmentation and shape identification tractable at industrial scale.

Provably fast solvers for constrained problems

The first algorithm shown to reach the multigrid convergence rate on obstacle-type problems — a guarantee that runtime scales with problem size rather than exploding.

Blood-flow simulation without a mesh

Physics-informed neural solvers for 3D flow in deformable vessels, built with medical-device partners. Removes the meshing step that usually makes patient-specific simulation impractical.

Explaining deep networks mathematically

Recent work showing that U-Nets, encoder–decoder networks and transformers can be read as classical numerical methods — which turns architecture design from trial and error into engineering.

What this can do for your business

Models that learn from your data, obey the physics, and run fast enough to act on

The approach I am developing now joins classical numerical mathematics with modern machine learning. Models that can be audited, that work on small datasets, and that answer in time for a live decision. That opens problems that were out of reach a few years ago.

So far this has served energy and metals, health, maritime, earth observation and manufacturing. The mathematics does not mind which sector comes next.

Working together

Four ways partners usually start

Feasibility study

A few weeks on your data to establish whether the problem is solvable and what accuracy is realistic, before you commit a budget.

Contract research

A defined algorithm or prototype delivered against your specification, with the option of a NORCE team around it.

Co-funded projects

Industry-partner role in Research Council of Norway, Horizon Europe and other schemes, where public funding carries much of the cost.

People

Co-supervised PhD or postdoc positions on your problem, and training for your engineers on the methods involved.

Background in numbers

Thirty years of applied mathematics, mostly with partners outside academia

250+Publications
13,000+Citations
16PhDs supervised
18Postdocs supervised
2026SIAM Fellow

PhD in applied mathematics, University of Jyväskylä (1991). Professor at the University of Bergen (1994–2021), Nanyang Technological University, Singapore (2007–2011), and Chair Professor and Head of Mathematics at Hong Kong Baptist University (2017–2022); Chief Research Scientist and Executive Program Director at COCHE, Hong Kong (2022–2023); Chief Scientist at NORCE since 2023. Feng Kang Prize for Scientific Computing (2009), Nanyang Award for Research Excellence (2011), Humboldt Scholarship (1993). Board member of NOBIM, the Norwegian association for image analysis and machine learning.

Editorial boards — work that keeps me current on what is actually working, well before it reaches textbooks or products: SIAM Journal on Numerical Analysis; SIAM Journal on Imaging Sciences; Journal of Mathematical Imaging and Vision; Inverse Problems and Imaging; East Asian Journal on Applied Mathematics; International Journal of Numerical Analysis and Modeling; Mathematical Foundations of Computing; Frontiers in Computer Science; Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization. Editor in Chief of Advances in Continuous and Discrete Models (2021–2024); Executive Editor of Numerical Mathematics: Theory, Methods and Applications (2005–2021).

Get in touch

Send me the problem, not a formal brief

A short description of what you measure, what you need to know from it, and how fast you need the answer is enough for me to say whether this is worth pursuing — and to be honest with you if it is not.

Emailxtai@norceresearch.no
Phone+47 56 10 78 30
Visiting addressFantoftvegen 38, 5072 Bergen, Norway
PublicationsGoogle Scholar · ResearchGate · Research.com · NVA · NORCE profile