The Umbra Simulation and Integration Framework Applied to Emergency Response Training

The Mine Emergency Response Interactive Training Simulation (MERITS) is intended to prepare personnel to manage an emergency in an underground coal mine. The creation of an effective training environment required realistic emergent behavior in response to simulation events and trainee interventions, exploratory modification of miner behavior rules, realistic physics, and incorporation of legacy code. It also required the ability to add rich media to the simulation without conflicting with normal desktop security settings. Our Umbra Simulation and Integration Framework facilitated agent-based modeling of miners and rescuers and made it possible to work with subject matter experts to quickly adjust behavior through script editing, rather than through lengthy programming and recompilation. Integration of Umbra code with the WebKit browser engine allowed the use of JavaScript-enabled local web pages for media support. This project greatly extended the capabilities of Umbra in support of training simulations and has implications for simulations that combine human behavior, physics, and rich media

Investigations of small-scale magnetic features on the solar surface

Solar activity is controlled by the magnetic field, which also causes the variability of the solar irradiance that in turn is thought to influence the climate on Earth. The magnetic field manifests itself in the form of structures of largely different sizes. This thesis concentrates on two types of the smallest known magnetic features: The first part studies the properties of umbral dots, dot-like bright features in the dark umbra of a sunspot. The obtained umbral dot properties provide a remarkable confirmation of the results of recent magneto-hydrodynamical simulations. Observations as well as simulations show that umbral dots differ from their surroundings mainly in the lowest photospheric layers, where the temperature is enhanced and the magnetic field is weakened. In addition, the interior of the umbral dots displays strong upflow velocities which are surrounded by weak downflows. This qualitative agreement further strengthens the interpretation of umbral dots as localized columns of overturning convection. The second part of the thesis investigates bright points, which are small-scale brightness enhancements in the darker intergranular lanes of the quiet Sun produced by magnetic flux concentrations. Observational data obtained by the balloon-borne solar telescope SUNRISE are used in this thesis. For the first time contrasts of bright points in the important ultraviolet spectral range are determined. A comparison of observational data with magneto-hydrodynamical simulations revealed a close correspondence, but only after effects due to the limited spectral and spatial resolution were carefully included. 98% of the synthetic bright points are found to be associated with a nearly vertical kilo-Gauss field.Comment: PhD thesis, Braunschweig University, 209 pages; ISBN 978-3-942171-73-1, uni-edition GmbH 201

Coordinated Machine Learning and Decision Support for Situation Awareness

For applications such as force protection, an effective decision maker needs to maintain an unambiguous grasp of the environment. Opportunities exist to leverage computational mechanisms for the adaptive fusion of diverse information sources. The current research employs neural networks and Markov chains to process information from sources including sensors, weather data, and law enforcement. Furthermore, the system operator\u27s input is used as a point of reference for the machine learning algorithms. More detailed features of the approach are provided, along with an example force protection scenario