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The direct kinematics problem is the problem of finding the actual pose of the moveable manipulator platform from the active joints‘ coordinates, for example, the linear actuators‘ lengths. For parallel mechanisms, it cannot be solved unambiguously. By measuring the linear actuators‘ orientations and the orientation of the manipulator platform instead, this problem can be solved analytically, and the actual pose of the manipulator platform can be determined without requiring any linear actuators‘ lengths. As an example, inertial measurement units can be used to obtain the orientation and motion of any body. In this thesis, this approach is applied to the general Stewart-Gough platform and the general planar 3-RPR parallel mechanism, and several formulations for solving the direct kinematics problem are derived. By totally renouncing length measurements and using inertial measurement units for measuring the orientations instead, a comprehensive, compact, and low-cost sensor system can be achieved, which provides an explicit pose of the manipulator platform and is also applicable to other parallel mechanisms.

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Semiconductor quantum dots (QDs) are of great topical interest due to the possibility to study basic quantum phenomena and their potential for novel applications. Here, the electronic and optical properties of semiconductor QDs are studied by means of tight-binding (TB) models combined with configuration interaction calculations. An empirical TB model is used to investigate the electronic states of group II-VI semiconductor QDs with a zinc blende structure. Within this approach pyramidal-shaped CdSe QDs embedded in a ZnSe matrix as well as spherical CdSe nanocrystals are studied. The theoretical results are found to be in excellent agreement with recent experimental data. Additionally, we study the electronic and optical properties of self-assembled nitride QDs. Excitonic absorption as well as multi-exciton emission spectra are analyzed for a series of different lens-shaped InN/GaN QDs. A dark exciton and biexciton ground state for small QDs is found. For larger structures, the strong electrostatic built-in fields lead to a level reordering for the hole states, which results in a bright exciton ground state. Furthermore, truncated pyramidal GaN/AlN QDs with zinc blende structure are investigated. Again, Coulomb and dipole matrix elements are evaluated from the single-particle wave functions and the optical spectra are analyzed. Finally, the results of our atomistic TB description are compared with continuum-like approaches.

Self-control theory, introduced by Michael Gottfredson and Travis Hirschi, emerged as a significant explanation for crime and deviance in the 20th century, yet it had little impact on public policy. The theory's perceived objectivity and alignment with the status quo of the criminal justice system contributed to its popularity, prompting extensive empirical research. However, critiques of the theory have been relatively sparse, raising questions about its validity and application in understanding criminal behavior.