arXiv Machine Learning

funOCLUST: Clustering Functional Data with Outliers

arXiv:2508. 00110v2 Announce Type: replace-cross Abstract: Functional data present unique challenges for clustering due to their infinite-dimensional nature and potential sensitivity to outliers.

arXiv Machine Learning
Sep 3

Clustering Three-Way Data with Outliers

The paper introduces a method for clustering matrix-variate normal data that accounts for outliers. It extends the OCLUST algorithm by employing subset log-likelihood distributions and an iterative trimming procedure. This approach enables robust clustering of complex structured data such as images and time series.

By Katharine M. Clark, Paul D. McNicholas
arXiv Statistics ML
Aug 31

Robust model-based clustering via mixtures of multivariate pseudo-Voigt distributions

The paper introduces a multivariate pseudo‑Voigt mixture model, combining Gaussian and Cauchy components with shared location and scale parameters, for robust clustering and outlier detection. Parameter estimation is performed using an EM algorithm that leverages latent variables for efficient likelihood inference. The authors evaluate the model through simulations and real data, comparing it to established robust mixtures such as contaminated normals, and demonstrate its effectiveness on heavy‑tailed datasets.

By Babak F. Dehkordi, Jeffrey L. Andrews, Andrew Jirasek
arXiv Machine Learning
Jun 16

Localized Kernel Projection Outlyingness: A Two-Stage Approach for Multi-Modal Outlier Detection

arXiv:2510. 24043v4 Announce Type: replace Abstract: This paper presents Two-Stage LKPLO, a novel multi-stage outlier detection framework that overcomes the coexisting limitations of conventional projection-based methods: their reliance on a fixed statistical metric and their assumption of a single data structure.

By Akira Tamamori
arXiv Machine Learning
Sep 11

Optimizing Three Critical Factors for Practical and Effective OOD Detection Fine-Tuning

The paper introduces a framework for out-of-distribution (OOD) detection that addresses the trade‑off between detection performance and classification accuracy caused by fine‑tuning with auxiliary outlier data. It optimizes three factors—model reminder, data sampling, and representation learning—by proposing Self‑Knowledge Distillation to preserve accuracy, Semi‑hard Outlier Sampling to enhance detection with minimal data, and Outlier‑aware Supervised Contrastive Learning to improve ID‑OOD separability. The combined approach yields cumulative gains, outperforming existing methods on diverse benchmarks, especially in long‑tailed scenarios, and offers a robust baseline for real‑world OOD detection.

By Hyunjun Choi, JaeHo Chung, Hawook Jeong
arXiv AI
Sep 4

Mixed Data Clustering Survey and Challenges

The paper "Mixed Data Clustering Survey and Challenges" discusses how the rise of big data has made clustering of heterogeneous datasets—containing both numerical and categorical variables—particularly difficult for traditional methods. It highlights the importance of hierarchical and explainable algorithms for producing interpretable results that aid decision‑making. The authors propose a new clustering approach based on pretopological spaces and benchmark it against classical numerical clustering algorithms and existing pretopological methods to evaluate its performance in the big data context.

By Maxence Choufa, Clement Cornet, Guillaume Guerard, Sonia Djebali, Loup-No\'e Levy