@phdthesis{Hupp2008,
  author    = {Hupp, Markus},
  title     = {Simulating Star Formation and Turbulence in Models of Isolated Disk Galaxies},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34510},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {We model Milky Way like isolated disk galaxies in high resolution three-dimensional hydrodynamical simulations with the adaptive mesh refinement code Enzo. The model galaxies include a dark matter halo and a disk of gas and stars. We use a simple implementation of sink particles to measure and follow collapsing gas, and simulate star formation as well as stellar feedback in some cases. We investigate two largely different realizations of star formation. Firstly, we follow the classical approach to transform cold, dense gas into stars with an fixed efficiency. These kind of simulations are known to suffer from an overestimation of star formation and we observe this behavior as well. Secondly, we use our newly developed FEARLESS approach to combine hydrodynamical simulations with a semi-analytic modeling of unresolved turbulence and use this technique to dynamically determine the star formation rate. The subgrid-scale turbulence regulated star formation simulations point towards largely smaller star formation efficiencies and henceforth more realistic overall star formation rates. More work is necessary to extend this method to account for the observed highly supersonic turbulence in molecular clouds and ultimately use the turbulence regulated algorithm to simulate observed star formation relations.},
  subject      = {Astrophysik},
  language  = {en}
}
@phdthesis{Wenisch2008,
  author    = {Wenisch, Jan},
  title     = {Ferromagnetic (Ga,Mn)As Layers and Nanostructures: Control of Magnetic Anisotropy by Strain Engineering},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34552},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {This work studies the fundamental connection between lattice strain and magnetic anisotropy in the ferromagnetic semiconductor (Ga,Mn)As. The first chapters provide a general introduction into the material system and a detailed description of the growth process by molecular beam epitaxy. A finite element simulation formalism is developed to model the strain distribution in (Ga,Mn)As nanostructures is introduced and its predictions verified by high-resolution x-ray diffraction methods. The influence of lattice strain on the magnetic anisotropy is explained by an magnetostatic model. A possible device application is described in the closing chapter.},
  subject      = {Magnetischer Halbleiter},
  language  = {en}
}
@phdthesis{Herbort2008,
  author    = {Herbort, Oliver},
  title     = {Encoding Redundancy for Task-dependent Optimal Control : A Neural Network Model of Human Reaching},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-26032},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {The human motor system is adaptive in two senses. It adapts to the properties of the body to enable effective control. It also adapts to different situational requirements and constraints. This thesis proposes a new neural network model of both kinds of adaptivity for the motor cortical control of human reaching movements, called SURE_REACH (sensorimotor unsupervised learning redundancy resolving control architecture). In this neural network approach, the kinematic and sensorimotor redundancy of a three-joint planar arm is encoded in task-independent internal models by an unsupervised learning scheme. Before a movement is executed, the neural networks prepare a movement plan from the task-independent internal models, which flexibly incorporates external, task-specific constraints. The movement plan is then implemented by proprioceptive or visual closed-loop control. This structure enables SURE_REACH to reach hand targets while incorporating task-specific contraints, for example adhering to kinematic constraints, anticipating the demands of subsequent movements, avoiding obstacles, or reducing the motion of impaired joints. Besides this functionality, the model accounts for temporal aspects of human reaching movements or for data from priming experiments. Additionally, the neural network structure reflects properties of motor cortical networks like interdependent population encoded body space representations, recurrent connectivity, or associative learning schemes. This thesis introduces and describes the new model, relates it to current computational models, evaluates its functionality, relates it to human behavior and neurophysiology, and finally discusses potential extensions as well as the validity of the model. In conclusion, the proposed model grounds highly flexible task-dependent behavior in a neural network framework and unsupervised sensorimotor learning.},
  subject      = {Bewegungssteuerung},
  language  = {en}
}
@phdthesis{Oeffner2008,
  author    = {Oeffner, Marc},
  title     = {AGENT-BASED KEYNESIAN MACROECONOMICS - An Evolutionary Model Embedded in an Agent-Based Computer Simulation},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39277},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Subject of the present study is the agent-based computer simulation of Agent Island. Agent Island is a macroeconomic model, which belongs to the field of monetary theory. Agent-based modeling is an innovative tool that made much progress in other scientific fields like medicine or logistics. In economics this tool is quite new, and in monetary theory to this date virtual no agent-based simulation model has been developed. It is therefore the topic of this study to close this gap to some extend. Hence, the model integrates in a straightforward way next to the common private sectors (i.e. households, consumer goods firms and capital goods firms) and as an innovation a banking system, a central bank and a monetary circuit. Thereby, the central bank controls the business cycle via an interest rate policy; the according mechanism builds on the seminal idea of Knut Wicksell (natural rate of interest vs. money rate of interest). In addition, the model contains also many Keynesian features and a flow-of-funds accounting system in the tradition of Wolfgang St{\"u}tzel. Importantly, one objective of the study is the validation of Agent Island, which means that the individual agents (i.e. their rules, variables and parameters) are adjusted in such a way that on the aggregate level certain phenomena emerge. The crucial aspect of the modeling and the validation is therefore the relation between the micro and macro level: Every phenomenon on the aggregate level (e.g. some stylized facts of the business cycle, the monetary transmission mechanism, the Phillips curve relationship, the Keynesian paradox of thrift or the course of the business cycle) emerges out of individual actions and interactions of the many thousand agents on Agent Island. In contrast to models comprising a representative agent, we do not apply a modeling on the aggregate level; and in contrast to orthodox GE models, true interaction between heterogeneous agents takes place (e.g. by face-to-face-trading).},
  subject      = {Mehragentensystem},
  language  = {en}
}
@phdthesis{Maier2008,
  author    = {Maier, Andreas},
  title     = {Adaptively Refined Large-Eddy Simulations of Galaxy Clusters},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32274},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {It is aim of this work to develop, implement, and apply a new numerical scheme for modeling turbulent, multiphase astrophysical flows such as galaxy cluster cores and star forming regions. The method combines the capabilities of adaptive mesh refinement (AMR) and large-eddy simulations (LES) to capture localized features and to represent unresolved turbulence, respectively; it will be referred to as Fluid mEchanics with Adaptively Refined Large-Eddy SimulationS or FEARLESS.},
  subject      = {Turbulenz},
  language  = {en}
}