Schedule

Date and Time: Tuesdays at 12:30PM

Location: MATH 126, The University of British Columbia, Vancouver, BC

•  September 17, 2024

  • Organizational meeting -- with pizza!

•  September 24, 2024

  • Manifold Optimization Reading Group (Geoffrey Woollard)

  • Review content in sections 3.1 and 3.2 

• October 1, 2024

  •  Speaker: Arash Mousemi

  • Title: “Three-Condition Uniform Conditional State Turbulent Combustion Model”.

  • Abstract: The three-condition Uniform Conditional State (UCS) turbulent combustion model is going to be described in which a chemistry table is made before conducting CFD simulation of the flow. The combination of a stochastic algorithm and a machine learning approach will be introduced for reducing the memory demand for loading the chemistry table.

• October 8, 2024

  • Manifold Optimization Reading Group (Boyan Beronov)

  • Review content from sections 3.2-3.7

• October 15, 2024

  • Speaker: Vincent Guan and Joseph Janssen

  • Title: “Initialization is all you need: Full identification of linear additive noise SDEs from temporal snapshots”.

  • Abstract: We provide necessary and sufficient conditions for the identifiability of linear additive noise SDEs from its marginal temporal distributions, characterized via the auto-rotational properties of the initial distribution. We then introduce the first method for identifying arbitrary linear additive noise SDEs, which alternates between trajectory inference (entropy minimization) and maximum likelihood parameter estimation. 

• October 22, 2024

  • Manifold Optimization Reading Group (Clément Soubrier)

  • Review content up to and including Section 4.3-Riemannian gradient descent 

• October 29, 2024

  • Speaker: Wenjun Zhao and Hossein Rahmani 

  • Title: “Causal Discovery and Applications to Gene Regulatory Networks”.

  • Abstract: They will first cover the basics of causal discovery for both the static and dynamic (time series) settings, and then discuss applications for inferring gene regulatory networks.

• November 5, 2024

  • Manifold Optimization Reading Group

• November 12, 2024

  • Reading break - No meeting

• November 19, 2024

• Speaker: Sophie Macdonald

• Title: “Optimal filtering by a model oyster”.

• Speaker: Jiyuan Dai

• Title: “Plastic failure modes of rectangles, triangles, and drums”.

• Speaker: Nicolas Morales

• Title: “Instability of Thin-Film Flows with Temperature-Dependent Viscosity”.

• November 26, 2024

  • Manifold Optimization Reading Group

• December 3, 2024

• AI and Research: a few demos / discussion of how to use AI tools productively in research.

• Vincent Guan: ChatGPT & research

• Lauren Bogo: Copilot & coding

• Hody Chang: notebookLM, for summarizing & comparing papers

• Avleen Kaur: ChatGPT for creating figures & graphs; AI for finding papers

• December 10, 2024

  • Manifold Optimization Reading Group

Date and Time: Tuesdays at 12:30PM

Location: MATH 203, The University of British Columbia, Vancouver, BC

• May 07, 2024

  • 1. Speaker: Ben Adcock (SFU)

    2. Title:  “CS4ML: A general framework for active learning with arbitrary data based on Christoffel functions”.

• It is based on work in this paper: https://openreview.net/pdf?id=aINqoP32cb

•  June 04, 2024

  • Speaker: Karan Bains

  • Title:  “Mathematical Modelling of Opioid Use Disorder/Treatment in BC”

  • Abstract: The toxic drug overdose crisis in British Columbia has continued at a high level for over eight years since the public health emergency was first declared in 2016. My supervisor Dr. Daniel Coombs, along with collaborators at the BC Centre for Disease Control and elsewhere, previously developed statistical models of the rates of overdose and death over time, with the goals of assessing the efficacy of the provincial public health response (Irvine et al, Lancet Public Health 2018, Addiction 2019 and International Journal of Drug Policy 2021). However, the style of modelling that they used in the previous work was population-based and did not include individual-based information that would allow them to answer questions, such as the total number of overdoses experienced by an individual over time, or incorporate individual-based data on time spent in treatment and time before relapse. I am currently working in collaboration with the BCCDC to fill this gap on the individual side!

Date and Time: Every Tuesday at 12:30PM

Location: MATH 203, The University of British Columbia, Vancouver, BC

• January 16, 2024

  • Speaker: Bernie Shizgal

  • Title: "Spectral Methods for the Fokker-Planck and Schrödinger equations: An Application to Space Physics"

• January 23, 2024

  • No meeting due to BC Transit strike.

• January 30, 2024

  • Speaker: Timon Gutleb

  • Title: "A frame approach for equations involving the fractional Laplacian”

• February 6, 2024

  • Speaker: Michael Ward

  • Title: “Synchronization of Oscillators through a PDE Diffusion Field: Derivation of a New Model System and Numerical Challenges for its solution.”

• February 13, 2024

  • Workshop on Automatic Differentiation - Part I: Forward-mode AD

  • Organizers: Cheuk (Jerry) Hin Ho, Christoph Ortner, Miranda Holmes-Cerfon

• February 20, 2024

  • Workshop on Automatic Differentiation - Part II: Reverse-mode AD

  • Organizers: Cheuk (Jerry) Hin Ho, Christoph Ortner, Miranda Holmes-Cerfon

• February 27, 2024

  • Workshop on Automatic Differentiation - Part III: A smorgasbord of AD in research and history

• Geoff Woollard: On modifying AD for nonstandard loss functions that appear in inverse problems

• Teemu Järvinen: On the story of how reverse mode AD was discovered

• Miranda Holmes-Cerfon: On using AD to optimize the outputs of reaction equations, with applications in inverse problems in self-assembly

• Cheuk (Jerry) Hin Ho: On Laplacian evaluation with HyperDuals (with background application in Variational Monte Carlo)

• March 5, 2024

  • Speaker: Dexuan Zhou

  • Title: “Solving many-electron Schrödinger equation with ACE”

• March 12, 2024

  • Special IAM/PACMAN Seminar

  • Speaker: Huajie Chen, Beijing Normal University Mathematical Sciences

  • Title: “Stability of the Minimal Energy Path”

  • Abstract: The minimum energy path (MEP) is the most probable transition path that connects two equilibrium states of a potential energy landscape. It has been widely used to study transition mechanisms as well as transition rates in the fields of chemistry, physics, and materials science. In this talk, we show a novel result establishing the stability of MEPs under perturbations of the energy landscape. The result also represents a crucial step towards studying the convergence of numerical discretisations of MEPs. This is a joint work with Xuanyu Liu (BNU) and Christoph Ortner (UBC).

• March 19, 2024

  • Speaker: Chunyi Gai

  • Title: "Pattern Formation and Spike Dynamics in the Presence of Noise"

  • Abstract: Noise plays a crucial role in the formation and evolution of spatial patterns in various reaction-diffusion systems in mathematical biology and ecology. In this talk, I give two examples where noise significantly influences spatial patterning. The first example describes how patterned states can provide a refuge and prevent extinction under stressed conditions. It also illustrates the importance of not only the absolute level of climate change, but also the speed with which it occurs. The second example studies the effect of noise on the dynamics of a single spike pattern for the classical Gierer--Meinhardt model on a finite interval.

• March 26, 2024

  • Speaker: Siting Liu (UCLA)

  • Title: "Optimization towards PDE computation and score-based generative models"

  • Abstract: In this talk, we will discuss optimization approaches towards partial differential equation (PDE) computations and score-based generative models (SGM). In numerical computations,  we propose a saddle point framework that leverages the inherent structure of PDEs. This framework, seamlessly integrated with existing discretization schemes, eliminates the need for nonlinear inversions and enables efficient parallelization. Shifting focus to SGM, we delve into the Wasserstein proximal operator (WPO) to understand the mathematical foundations of SGM – it can be written as the Wasserstein proximal operators of cross-entropy. Leveraging PDE formulation of WPO, we propose an WPO-informed score model which showcases accelerated training and reduced data requirements.

• April 2, 2024

  • Speaker: Siddharth Rout

  • Title: "Using neural networks for solving PDEs with severe advection" &"PDE based neural architectures for forecasting spatiotemporal dynamics like chaotic Lorenz 96, cloud transport and MovingMNIST"

• April 09, 2024

  • Speaker: Boyan Beronov

  • Partner Speaker: Jordan Lovrod

  •  Title: "Revisiting some classical results on Volterra IDEs, with a motivation from dynamic DNA nanotechnology"

  • Abstract: Kinetic/dynamic Monte Carlo algorithms are widely used for sampling-based approximations of the non-equilibrium behaviour of jump processes. However, they face fundamental scaling problems when the state space is combinatorial, e.g., when simulating the chemical kinetics of DNA computing circuits at the level of elementary conformation changes. Alternatively, one may relax the constitutive differential equations into functional differential equations of convolution type, and pursue an approximation of their Volterra integral operators using combinatorial information that is inaccessible to purely local methods.

The core part of this talk will review some classical results on the theory and numerical approximation of Volterra IDEs. In the beginning, the partner speaker Jordan Lovrod will introduce chemical reaction networks, which in this context serve both as biochemical models and as abstract models of computation.

• April 16, 2024

  • Speaker: Tina Torabi

  • Partner Speaker: Christoph Ortner

  • Title: "Developing surrogate models for vibrational entropy"

Date and Time: Every Tuesday at 12:30PM

Location: MATH 126, The University of British Columbia, Vancouver, BC

• September 26, 2023

  • Speaker: Brian Wetton

  • Partner Speaker: Joshua Renault

  • Title: "Asymptotic Error Analysis"

• October 3, 2023

  • Speaker: Zelai Xu

  • Partner Speaker: Sherril Wang

  • Title: "The swelling of a hydrogel with an external flow"

• October 10, 2023

  • No talks - Faculty Meeting

• October 16, 2023

  • Lightning Talks: 

• • 1. Wanxin Li: "Using a Riemannian elastic metric for statistical analysis of tumor cell shape heterogeneity"

    2. Siddharth Rout: "Single shot meshless ODE solver"

    3. Rui Gao: "A finite element-inspired hypergraph neural network: Applications in fluid dynamics and fluid-structure interaction"

    4. Jerry Hin Ho: "Atomic Cluster Expansion - theory and applications in machine learning interatomic potentials"

• October 24, 2023

  • Speaker:  Timon Gutleb

  • Title: "Solving time-fractional PDEs with static memory for medical ultrasound applications"

• October 31, 2023

  • Speaker:  Avleen Kaur

  • Partner Speaker:  Merlin Pelz

  • Title: "Space-time spectral methods for PDEs"

• November 7, 2023

  • In lieu of PACMAN seminar, we had the following IAM Seminar.

    • Location: IAM Lounge (LSK 306)

    • Speaker: Xuenan Li, Columbia University - Applied Physics and Applied Mathematics

    • Title: "The Kagome Lattice As a Mechanism-Based Metamaterial"

• November 14, 2023

  • Fall Break

• November 21, 2023

  • Speaker: Teemu Järvinen

  • Partner Speaker: Kudzanayi Zebedia Mapfumo

  • Title: "Using Greens functions to solve Helmholtz and Poisson equations"

• November 28, 2023

  • Speaker: Victor Juma

  • Title: "Incorporating clinical data for enhanced radiotherapy treatment planning"

• December 5, 2023

  • Speaker: Maricela Best Mckay

  • Special time: **12:45pm**

  • Title/Description: "Physics Informed Neurally Constructed ODE Networks (PINECONES)". The work presents a novel architecture for approximating PDEs with Neural Networks. The architecture combines a Neural ODE with a physics informed loss and tests its performance on simple benchmark problems. 

• February 9, 2023 

  • Time: 12:30PM

  • Speakers: Damien Huet, Zelai Xu 

• February 16, 2023  

  • Time: 12:30PM

  • Shikun Nie: “Super resolution imaging with a hairpin structured molecular imager, and how understanding the mechanism of this imager can lead to new algorithms to improve its localization accuracy.”

  • Liam Yih: “Modelling Virions Using Stochastic Chains”

• February 23, 2023 

  •  No meeting — Reading week

• March 2, 2023  

  • Time: 11:30AM

  • Liwei Zhang:  “A generalized Atomic Cluster Expansion framework and its applications in electronic structure calculations”

  • Chunyi Gai: “Hotspot formation and dynamics for the urban crime model with police deployment.”

• March 9, 2023  

  • Time: 11:30AM

  • Geoff Woolard:  “Solving an inverse problem of cryogenic electron microscopy of biomolecules with stochastic variational inference”

  • Anirudh Mukundan: “Numerical modelling of red blood cells from a mechanical engineering point of view”

• March 16, 2023  

  • Time: 11:30AM

  • Jordon Lovrod (c)

  • Anne Condon:  “Some mathematical and computational challenges in the field of DNA computing”

• March 23, 2023  

  • Time: 11:30AM

  • Clément Soubrier 

  • Khanh Dao Duc: “I will talk about a current project on long time lapse imaging of bacterial division from atomic force microscopy”

• March 30, 2023  

  • Time: 12:30PM

  • Xiaoyu Mao: "A unified Eulerian variational framework for multiphase fluid-structure interaction". 

  • Biswajee Rath: “Xiaoyu will introduce the basic concepts of the formulation in the first half. I will then discuss a few specifics of the work we have done in the past and are presently working on."

• April 6, 2023 

  • Time: 12:30PM

  • Geoff Woolard:  “Solving an inverse problem of cryogenic electron microscopy of biomolecules with stochastic variational inference”

  • Khanh Dau Duc: “I will introduce the general context and problem of single particle Cryo-EM”

• April 20, 2023  

  • Time: 12:30PM

  • Anirudh Mukundan