Introduction to the issue on anomalous pattern discovery for spatial, temporal, networked, and high-dimensional signals

This special issue features papers that highlight a variety of anomaly detection techniques in the context of many important applications including networks, homeland security, and healthcare.We accepted 13 papers for publication out of a large number of submitted manuscripts. The first series of seven papers appearing in the special issue are focused on new problem structures. The next set of six papers are somewhat focused more towards specific applications. Several papers in the first half of the special issue are generally motivated by applications arising in sensor, communication and social networks. The next set of three papers describes techniques for homeland security and surveillance applications.