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A master's thesis from Aalborg University
Book cover


Hyperbolic Generalized Category Discovery: Hyperbolic visual learning and clustering for generalized category discovery

Translated title

Hyperbolic Generalized Category Discovery

Author

Term

4. semester

Publication year

2025

Submitted on

Pages

56

Abstract

Afhandlingen undersøger, om repræsentationer i hyperbolsk geometri kan hjælpe en open-world klassifikationsmodel med både at genkende kendte klasser og opdage nye (Generalized Category Discovery, GCD). Vi tilpasser to GCD-metoder til at lære indlejninger (kompakte numeriske repræsentationer) i Lorentz-modellen for hyperbolsk geometri, og vi ændrer K-Means-algoritmen, så den kan klynge direkte i hyperbolsk rum (en ikke-parametrisk tilgang). Forsøgene viser, at den ikke-parametriske metode nyder godt af at lære i Lorentz-rum, mens den parametriske metode ikke gør og klarer sig bedst i det almindelige euklidiske rum. Vi ser også højere nøjagtighed, når K-Means udføres direkte i Lorentz-modellen; derimod er K-Means i Poincaré-modellen ustabil og kan mislykkes med at danne gyldige klynger afhængigt af initialiseringen af klyngeprototyperne.

This thesis explores whether representing data in hyperbolic geometry can help an open-world classifier both recognize known classes and discover new ones, a task known as Generalized Category Discovery (GCD). We adapt two GCD methods to learn embeddings (compact numerical representations) in the Lorentz model of hyperbolic geometry, and we modify the K-Means algorithm so it can cluster points directly in hyperbolic space (a non-parametric approach). Experiments show that the non-parametric method benefits from learning in Lorentz space, whereas the parametric method does not and performs best in standard Euclidean space. We also find higher accuracy when running K-Means directly in the Lorentz model; in contrast, K-Means in the Poincaré model is unstable and may fail to form valid clusters depending on how the cluster prototypes are initialized.

[This summary has been rewritten with the help of AI based on the project's original abstract]