Z-Embedding: A Spectral Representation of Event Intervals for Efficient Clustering and Classification
2021 (English)In: Machine Learning And Knowledge Discovery In Databases, ECML PKDD 2020, Pt I / [ed] Hutter, F Kersting, K Lijffijt, J Valera, I, Springer Nature , 2021, Vol. 12457, p. 710-726Conference paper, Published paper (Refereed)
Abstract [en]
Sequences of event intervals occur in several application domains, while their inherent complexity hinders scalable solutions to tasks such as clustering and classification. In this paper, we propose a novel spectral embedding representation of event interval sequences that relies on bipartite graphs. More concretely, each event interval sequence is represented by a bipartite graph by following three main steps: (1) creating a hash table that can quickly convert a collection of event interval sequences into a bipartite graph representation, (2) creating and regularizing a bi-adjacency matrix corresponding to the bipartite graph, (3) defining a spectral embedding mapping on the bi-adjacency matrix. In addition, we show that substantial improvements can be achieved with regard to classification performance through pruning parameters that capture the nature of the relations formed by the event intervals. We demonstrate through extensive experimental evaluation on five real-world datasets that our approach can obtain runtime speedups of up to two orders of magnitude compared to other state-of-the-art methods and similar or better clustering and classification performance.
Place, publisher, year, edition, pages
Springer Nature , 2021. Vol. 12457, p. 710-726
Series
Lecture Notes in Artificial Intelligence, ISSN 0302-9743
Keywords [en]
Event intervals, Bipartite graph, Spectral embedding, Clustering, Classification
National Category
Computer Sciences
Identifiers
URN: urn:nbn:se:kth:diva-305540DOI: 10.1007/978-3-030-67658-2_41ISI: 000717522300041Scopus ID: 2-s2.0-85103244865OAI: oai:DiVA.org:kth-305540DiVA, id: diva2:1620342
Conference
European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD), SEP 14-18, 2020, ELECTR NETWORK
Note
QC 20211215
Conference ISBN 978-3-030-67658-2; 978-3-030-67657-5
2021-12-152021-12-152022-06-25Bibliographically approved