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Showing result 1 - 5 of 20 swedish dissertations matching the above criteria.

2. 1. Stochastic Resonance and Noise-Assisted Signal Transfer : On Coupling Effects of Stochastic Resonators and Spectral Optimization of Fluctuations in Random Network Switches

   Author : Peter Hammerstein; Claes Granqvist; Laszlo Kish; Hans Liljenström; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; stochastic resonance; nonlinear stochastic dynamics; noise and fluctuations; magnetic domains; Teknisk fysik; Engineering physics; Teknisk fysik;

   Abstract : Recent research shows that noise or random fluctuations must not always be destructive in Nature by degrading system performance. On the contrary, in nonlinear systems they can synchronize systems or enhance the quality of signal transmission. The latter possibility is reported in the thesis. READ MORE

4. 2. A Serendipitous Journey through Stochastic Processes

   Author : Ludovico Theo Giorgini; John S Wettlaufer; Valerio Lucarini; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Stochastic process; statistical physics; machine learning; Theoretical Physics; teoretisk fysik;

   Abstract : In this PhD thesis we will present some new insights in different problems in the field of stochastic processes. A stochastic resonance system is studied using path integral techniques, originally developed in quantum field theory, to recover the optimal means through which noise self-organises before a rare transition from one potential well to the other. READ MORE

5. 3. Optimal Detectors for Transient Signal Families and Nonlinear Sensors : Derivations and Applications

   Author : Daniel Asraf; Mats Gustafsson; Anders Grennberg; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; optimal detection; transient signals; noncoherent detection; unknown arrival time; ultrasonic nondestructive testing; nonlinear sensor; stochastic resonance; Signalbehandling; Signal processing; Signalbehandling; Signal Processing; signalbehandling;

   Abstract : This thesis is concerned with detection of transient signal families and detectors in nonlinear static sensor systems. The detection problems are treated within the framework of likelihood ratio based binary hypothesis testing. READ MORE

6. 4. Noise improves cognitive performance in children with dysfunctional neurotransmission

   Author : Göran Söderlund; Sverker Sikström; Lars-Göran Nilsson; Edmund Sonuga-Barke; Stockholms universitet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; ADHD; noise; stochastic resonance; dopamine; episodic memory; model; brain arousal; SPT; cognitive performance; children; Psychology; Psykologi; psykologi; Psychology;

   Abstract : Research on children with Attention Deficit Hyperactivity Disorder (ADHD) has shown that they are extremely sensitive to distraction from external stimuli that lead to poor cognitive performance. This thesis shows that cognitive performance can be improved if this external stimulus is smooth and continuous (e.g. auditory white noise). READ MORE

7. 5. Signals and Noise in Complex Biological Systems

   Author : Johan Rung; Erkki Brändas; Måns Ehrenberg; Uppsala universitet; []
   Keywords : Engineering physics; complex systems; computational biology; gene networks; genome-wide; stochastic resonance; microarray; diabetes; association study; transcription regulation; gene expression; Teknisk fysik;

   Abstract : In every living cell, millions of different types of molecules constantly interact and react chemically in a complex system that can adapt to fluctuating environments and extreme conditions, living to survive and reproduce itself. The information required to produce these components is stored in the genome, which is copied in each cell division and transferred and mixed with another genome from parent to child. READ MORE