SECLEDS: Sequence Clustering in Evolving Data Streams via Multiple Medoids and Medoid Voting

SECLEDS: Sequence Clustering in Evolving Data Streams via Multiple Medoids and Medoid Voting

Nadeem, A. (TU Delft Cyber Security)
Verwer, S.E. (TU Delft Cyber Security)

Amini, Massih-Reza (editor)
Canu, Stéphane (editor)
Fischer, Asja (editor)
Guns, Tias (editor)
Kralj Novak, Petra (editor)
Tsoumakas, Grigorios (editor)

2023

Sequence clustering in a streaming environment is challenging because it is computationally expensive, and the sequences may evolve over time. K-medoids or Partitioning Around Medoids (PAM) is commonly used to cluster sequences since it supports alignment-based distances, and the k-centers being actual data items helps with cluster interpretability. However, offline k-medoids has no support for concept drift, while also being prohibitively expensive for clustering data streams. We therefore propose SECLEDS, a streaming variant of the k-medoids algorithm with constant memory footprint. SECLEDS has two unique properties: i) it uses multiple medoids per cluster, producing stable highquality clusters, and ii) it handles concept drift using an intuitive Medoid Voting scheme for approximating cluster distances. Unlike existing adaptive algorithms that create new clusters for new concepts, SECLEDS follows a fundamentally different approach, where the clusters themselves evolve with an evolving stream. Using real and synthetic datasets, we empirically demonstrate that SECLEDS produces high-quality clusters regardless of drift, stream size, data dimensionality, and number of clusters. We compare against three popular stream and batch clustering algorithms. The state-of-the-art BanditPAM is used as an offline benchmark. SECLEDS achieves comparable F1 score to BanditPAM while reducing the number of required distance computations by 83.7%. Importantly, SECLEDS outperforms all baselines by 138.7% when the stream contains drift. We also cluster real network traffic, and provide evidence that SECLEDS can support network bandwidths of up to 1.08 Gbps while using the (expensive) dynamic time warping distance.

Sequence Clustering
k-medoids
stream processing
network traffic sampling

http://resolver.tudelft.nl/uuid:1c6c2732-6fa7-4356-a71e-6387048932d2

https://doi.org/10.1007/978-3-031-26387-3_10

Springer, Cham

2023-09-17

978-3-031-26386-6

Machine Learning and Knowledge Discovery in Databases.: European Conference, ECML PKDD 2022, Proceedings (Part 1)

ECML PKDD 2022, 2022-09-19 → 2022-09-23, Grenoble, France

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 0302-9743, 13713

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

conference paper

© 2023 A. Nadeem, S.E. Verwer