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Luke Ong

11 accepted papers

2025

Towards Interpreting Visual Information Processing in Vision-Language Models

ICLR 2025poster

Vision-Language Models (VLMs) are powerful tools for processing and understanding text and images. We study the processing of visual tokens in the language model component of LLaVA, a prominent VLM. Our approach focuses on analyzing the localization of object information, the evolution of visual tok…

2024

Beyond Bayesian Model Averaging over Paths in Probabilistic Programs with Stochastic Support

AISTATS 2024poster

The posterior in probabilistic programs with stochastic support decomposes as a weighted sum of the local posterior distributions associated with each possible program path. We show that making predictions with this full posterior implicitly performs a Bayesian model averaging (BMA) over paths. This…

2024

Diagonalisation SGD: Fast & Convergent SGD for Non-Differentiable Models via Reparameterisation and Smoothing

AISTATS 2024poster

It is well-known that the reparameterisation gradient estimator, which exhibits low variance in practice, is biased for non-differentiable models. This may compromise correctness of gradient-based optimisation methods such as stochastic gradient descent (SGD). We introduce a simple syntactic framewo…

2024

Reinforcement Learning with LTL and $\omega$-Regular Objectives via Optimality-Preserving Translation to Average Rewards

NeurIPS 2024poster

Linear temporal logic (LTL) and, more generally, $\omega$-regular objectives are alternatives to the traditional discount sum and average reward objectives in reinforcement learning (RL), offering the advantage of greater comprehensibility and hence explainability. In this work, we study the relatio…

Cited by 1SourcePDFScholar
2023

Exact Bayesian Inference on Discrete Models via Probability Generating Functions: A Probabilistic Programming Approach

NeurIPS 2023oral

We present an exact Bayesian inference method for discrete statistical models, which can find exact solutions to a large class of discrete inference problems, even with infinite support and continuous priors. To express such models, we introduce a probabilistic programming language that supports dis…

2022

Expectation programming: Adapting probabilistic programming systems to estimate expectations efficiently

UAI 2022poster

We show that the standard computational pipeline of probabilistic programming systems (PPSs) can be inefficient for estimating expectations and introduce the concept of expectation programming to address this. In expectation programming, the aim of the backend inference engine is to directly estimat…

Cited by 3SourcePDFScholar
2022

Rethinking Variational Inference for Probabilistic Programs with Stochastic Support

NeurIPS 2022accept

We introduce Support Decomposition Variational Inference (SDVI), a new variational inference (VI) approach for probabilistic programs with stochastic support. Existing approaches to this problem rely on designing a single global variational guide on a variable-by-variable basis, while maintaining th…