Therese S Pedersen

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The design of the positioning controllers in Optical Disk Drives are today subjected to a trade off between an acceptable suppression of external disturbances and an acceptable immunity against surfaces defects. In this paper an algorithm is suggested to detect defects of the disk surface combined with an observer and a Linear Quadratic Regulator. As a(More)
By measuring the current through the coil of the actuators in the optical pick-up in a compact disk player, open loop parametric system identification can be performed. The parameters are identified by minimizing the least-squares loss function of the ARX model. The only parameter which cannot be identified in open loop is the optical gain. This is(More)
High resolution measurements on the Alcator C-Mod tokamak [I.H. Hutchinson et al, Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the “Enhanced Dα” (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12(More)
Female addicts (N= 108) with a mean age of 37.2 were tested using the Temperament and Character Inventory (TCI) in 1996-97. In a representative sub-sample (N = 49) assessed with the Structured Clinical Interview. DSMIIIr (SCID), 82% manifested an axis-1-syndrome (lifetime), and 53% a personality disorder. Of the 108 addicts, 42 preferred alcohol, 14 heroin,(More)
Control of compact disc mechanisms is highly challenging not least due to the many conflicting control objectives arising from a large number of disturbances of rather different physical natures. A method is proposed which enables the control system to distinguish between some of the disturbance classes. A significant robustness problem is solved by a(More)
In this work screen printed piezoelectric Ferroperm PZ26 lead zirconate titanate (PZT) thick film is used for two MEMS devices. A test structure is used to investigate several aspects regarding bottom and top electrodes. 450 nm ZrO2 thin film is found to be an insufficient diffusion barrier layer for thick film PZT sintered at 850°C. E-beam evaporated Al(More)
Dark-mode plasmon resonances can be excited by positioning a suitable nano-antenna above a nanostructure to couple a planar incident wave-front into a virtual point source. We explore this phenomenon using a prototypical nanostructure consisting of a silver nanotriangle into which a hole has been drilled and a rod-like nano-antenna of variable aspect ratio.(More)
Trace non-recycling impurities (Sc and CaF2) have been injected into Alcator C-Mod plasmas in order to determine impurity transport coefficient profiles in a number of operating regimes. Recycling Ar has also been injected to characterize steady state impurity density profiles. Subsequent impurity emission has been observed with spatially scanning x-ray and(More)