Search Results for author: Nick Whiteley

Found 11 papers, 7 papers with code

Hierarchical clustering with dot products recovers hidden tree structure

1 code implementation NeurIPS 2023 Annie Gray, Alexander Modell, Patrick Rubin-Delanchy, Nick Whiteley

In this paper we offer a new perspective on the well established agglomerative clustering algorithm, focusing on recovery of hierarchical structure.

Clustering

Implications of sparsity and high triangle density for graph representation learning

no code implementations27 Oct 2022 Hannah Sansford, Alexander Modell, Nick Whiteley, Patrick Rubin-Delanchy

Recent work has shown that sparse graphs containing many triangles cannot be reproduced using a finite-dimensional representation of the nodes, in which link probabilities are inner products.

Graph Representation Learning Vocal Bursts Intensity Prediction

Statistical exploration of the Manifold Hypothesis

2 code implementations24 Aug 2022 Nick Whiteley, Annie Gray, Patrick Rubin-Delanchy

The Manifold Hypothesis is a widely accepted tenet of Machine Learning which asserts that nominally high-dimensional data are in fact concentrated near a low-dimensional manifold, embedded in high-dimensional space.

Consistent and fast inference in compartmental models of epidemics using Poisson Approximate Likelihoods

1 code implementation26 May 2022 Michael Whitehouse, Nick Whiteley, Lorenzo Rimella

In contrast to the popular ODE approach to compartmental modelling, in which a large population limit is used to motivate a deterministic model, PALs are derived from approximate filtering equations for finite-population, stochastic compartmental models, and the large population limit drives consistency of maximum PAL estimators.

Bayesian Inference

Matrix factorisation and the interpretation of geodesic distance

1 code implementation NeurIPS 2021 Nick Whiteley, Annie Gray, Patrick Rubin-Delanchy

Given a graph or similarity matrix, we consider the problem of recovering a notion of true distance between the nodes, and so their true positions.

Dimensionality Reduction

Inference in Stochastic Epidemic Models via Multinomial Approximations

1 code implementation24 Jun 2020 Nick Whiteley, Lorenzo Rimella

We introduce a new method for inference in stochastic epidemic models which uses recursive multinomial approximations to integrate over unobserved variables and thus circumvent likelihood intractability.

Dynamic Bayesian Neural Networks

no code implementations15 Apr 2020 Lorenzo Rimella, Nick Whiteley

We define an evolving in time Bayesian neural network called a Hidden Markov neural network.

Time Series Time Series Analysis

Dynamic time series clustering via volatility change-points

1 code implementation25 Jun 2019 Nick Whiteley

This note outlines a method for clustering time series based on a statistical model in which volatility shifts at unobserved change-points.

Methodology Statistical Finance

Exploiting locality in high-dimensional factorial hidden Markov models

1 code implementation5 Feb 2019 Lorenzo Rimella, Nick Whiteley

We propose algorithms for approximate filtering and smoothing in high-dimensional Factorial hidden Markov models.

Vocal Bursts Intensity Prediction

The infinite Viterbi alignment and decay-convexity

no code implementations8 Oct 2018 Nick Whiteley, Matt W. Jones, Aleks P. F. Domanski

Quantitative bounds on the distance to the infinite Viterbi alignment, which are the first of their kind, are derived and used to illustrate how approximate estimation via parallelization can be accurate and scaleable to high-dimensional problems because the rate of convergence to the infinite Viterbi alignment does not necessarily depend on $d$.

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