Ronnie Johansson

Learn More
We study the combination problem for credal sets via the robust Bayesian combination operator. We extend Walley’s notion of degree of imprecision and introduce a measure for degree of conflict between two credal sets. Several examples are presented in order to explore the behavior of the robust Bayesian combination operator in terms of imprecision and(More)
We use agent-based modeling and simulation to fuse data from multiple sources to estimate the state of some system properties. This implies that the real system of interest is modeled and simulated using agent principles. Using Monte-Carlo simulation, we estimate the values of some decision-relevant numerical properties. We use the estimated properties,(More)
We extend the State-Based Anomaly Detection approach by introducing precise and imprecise anomaly detectors using the Bayesian and credal combination operators, where evidences over time are combined into a joint evidence. We use imprecision in order to represent the sensitivity of the classification regarding an object being normal or anomalous. We(More)
A more precise definition of the field of information fusion can be of benefit to researchers within the field, who may use such a definition when motivating their own work and evaluating the contribution of others. Moreover, it can enable researchers and practitioners outside the field to more easily relate their own work to the field and more easily(More)
We propose a two-stage method based on multiple distributed sensors for detection of piracy operations at sea. The proposed method is based on fusion of evidence from radar and optical sensors as well as AIS signals. The sensors are land based, air based and space based. In the first stage, a number of detectors perform recognition of low-level events, such(More)
Bayesian theory [5] is one of the most commonly utilized theories for managing uncertainty in information fusion [20, 12]. The theory relies on two main assumptions: (1) a probability function should be used for representing belief and (2) Bayes’ theorem should be used for belief updating when a new observation has been made. The main criticism of Bayesian(More)
By purposefully utilising sensors, for instance by a data fusion system, the state of some system-relevant environment might be adequately assessed to support decision-making. The ever increasing access to sensors offers great opportunities, but also incurs grave challenges. As a result of managing multiple sensors one can, e.g., expect to achieve a more(More)
Ensemble classifiers are known to generally perform better than each individual classifier of which they consist. One approach to classifier fusion is to apply Shaferpsilas theory of evidence. While most approaches have adopted Dempsterpsilas rule of combination, a multitude of combination rules have been proposed. A number of combination rules as well as(More)