P. Parrend

Introducing h-leading-ones as a mixed-category benchmark problem for evolutionary algorithms

By C. Frappé–Vialatoux, P. Parrend

2025-04-18

In Genetic and evolutionary computation conference (GECCO)

Abstract

In the wake of generative artificial intelligence and the exponential growth in the volume of data generated, the associated increase in data complexity in the sense of the quantity of different datatypes present in a single system poses a challenge to evolutionary algorithms. To allow for the development and testing of new algorithms adapted to this new data landscape, test problems are necessary as a way to both evaluate and compare algorithms per-formances. However, while recent advances extended known test problems such as the r-Leading-Ones marking the transition from binary to multi-valued variables, having different data-types coexisting in the search space is still an open question. We propose the h-Leading-Ones as an extension of the r-Leading-Ones to evaluate the ability of an algorithm to solve problems on a search space composed of multi-valued and real-valued data types. Its design with dependency between the different data-types and its continuity with the r-Leading-Ones provides a convenient new environment for benchmark and runtime analysis for mixed-category searchspaces.

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Spectral graph analysis of bipartite graphs for advanced attack detection

By M. Jaber, P. Parrend, N. Boutry

2025-04-15

In European interdisciplinary cybersecurity conference (EICC25)

Abstract

Spectral graph theory offers powerful tools for understanding graph properties through spectral signatures. This work leverages the inherent link between graph topology and spectral characteristics to enhance anomaly detection in network traffic, particularly in medical IoT networks. We introduce SPECTRA, a spectral graph analysis technique designed to detect anomalies in dynamic and complex network structures. This method incorporates five spectral metrics, including the newly proposed BiFlowness metric derived from Singular Value Decomposition (SVD), which captures the f low dynamics within bipartite graph topologies. By combining these spectral metrics, SPECTRA provides a comprehensive model for detecting and analyzing advanced cyberattack patterns, such as multistep intrusions, in critical systems. Focusing on hybrid topologies that integrate star and bipartite structures, this technique applies spectral analysis to evolving networks, enabling the detection of attacks (port scanning, fingerprinting) over time. Performed experiments validate the effectiveness of SPECTRA across IoT datasets, demonstrating its superiority in identifying attack behaviors. The proposed approach aligns with the critical demands of medical IoT environments by providing a good threat detection procedure to enhance security in sensitive networks.

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