1 research outputs found
Why did the shape of your network change? (On detecting network anomalies via non-local curvatures)
problems (also called -
problems) have been studied in data mining, statistics and computer science
over the last several decades in applications such as medical condition
monitoring and weather change detection. In recent days, however, anomaly
detection problems have become increasing more relevant in the context of
since useful insights for many complex systems in biology,
finance and social science are often obtained by representing them via
networks. Notions of local and non-local curvatures of higher-dimensional
geometric shapes and topological spaces play a role in physics
and mathematics in characterizing anomalous behaviours of these higher
dimensional entities. However, using curvature measures to detect anomalies in
networks is not yet very common. To this end, a main goal in this paper to
formulate and analyze curvature analysis methods to provide the foundations of
systematic approaches to find and
in networks. For this purpose, we use two measures of network curvatures which
depend on non-trivial global properties, such as distributions of geodesics and
higher-order correlations among nodes, of the given network. Based on these
measures, we precisely formulate several computational problems related to
anomaly detection in static or dynamic networks, and provide non-trivial
computational complexity results for these problems. This paper must be
viewed as delivering the final word on appropriateness and suitability of
specific curvature measures. Instead, it is our hope that this paper will
stimulate and motivate further theoretical or empirical research concerning the
exciting interplay between notions of curvatures from network and non-network
domains, a desired goal in our opinion.Comment: Final revised version; to appear in Algorithmic