In streaming applications, it is often required to detect situations of interest, by means of temporal pattern matching, with minimal latency. In the maritime domain, e.g., where it is crucial to prevent activities that are harmful to the environment, we need to report illegal fishing activities, based on streams of low-level vessel actions, as soon as possible. Streams often include events with delayed effects. In multi-agent voting protocols, e.g., a proposed motion may be seconded at the latest by some time in the future. In simulations of biological systems, a signal may lead to the deactivation of the functions of a gene after a time delay. We propose a formal computational framework that handles streams including events with delayed effects. We present the syntax, semantics and reasoning algorithms of our proposed framework, and demonstrate its correctness and complexity. Furthermore, we present a reproducible analysis on large synthetic and real data streams, from the fields of composite event recognition, multi-agent systems and biological feedback processes, and compare the efficiency of our approach with state-of-the-art systems that can perform stream reasoning in these domains. Our results demonstrate that our framework is capable of reasoning over very large streams, including events with delayed effects, while outperforming the state-of-the-art, often by orders of magnitude.

The shipping industry is an important component of the global trade and economy. In order to ensure law compliance and safety, it needs to be monitored. In this paper, we present a novel ship type classification model that combines vessel transmitted data from the Automatic Identification System, with vessel imagery. The main components of our approach are the Faster R-CNN Deep Neural Network and a Neuro-Fuzzy system with IF-THEN rules. We evaluate our model using real world data and showcase the advantages of this combination while also compare it with other methods. Results show that our model can increase prediction scores by up to 15.4% when compared with the next best model we considered, while also maintaining a level of explainability as opposed to common black box approaches.

While an abundance of real-time maritime information exists and is readily available to monitoring authorities, there are still many instances in which ships are found to be engaged in dangerous or illegal activities. In order to prevent such activities, authorities employ Vessel Traffic Services systems since they promote safety at sea while also assisting in management of ports. In this paper we report on research done in cooperation with Denbridge Marine Ltd., a global provider of maritime solutions, and present an application integrated in a Vessel Tracking Services system that allows the detection of normal vessel activity as well as dangerous or illegal situations in real-time, using information from the Automatic Identification System, a radar sensor and other information. We use a set of phenomena representing maritime activities of interest in the language of Phenesthe, our Complex Event Processing engine, and detect them on real maritime data streams from the area of Liverpool, United Kingdom. We evaluate our application and show that our system is capable of detecting and visualising maritime activities on the map in real time. Finally, we study and demonstrate the significance of using data from the Automatic Identification System along with radar data for maritime monitoring.

In the maritime domain, vessels typically maintain straight, predictable routes at open sea, except in the rare cases of adverse weather conditions, accidents and traffic restrictions. Consequently, large amounts of streaming positional updates from vessels can hardly contribute additional knowledge about their actual motion patterns. We have been developing a system for vessel trajectory compression discarding a significant part of the original positional updates, with minimal trajectory reconstruction error. In this work, we present an extension of this system, that allows the user to fine-tune trajectory compression according to the requirements of a given application. The extended system avoids the issues of hyper-parameter tuning, supports incremental optimization and facilitates composite maritime event recognition. Finally, we report empirical results from a comprehensive empirical evaluation against two real-world datasets of vessel positions.