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Visar resultat 1 - 5 av 26 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Multidimensional inverse problems in imaging and identification using low-complexity models, optimal mass transport, and machine learning

   Författare :Axel Ringh; Johan Karlsson; Rodolphe Sepulchre; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inverse problems; convex optimization; variational regularization; trigonometric moment problems; optimal mass transport; computed tomography; machine learning; analytic interpolation; delay systems; Inversa problem; konvex optimering; variationell regularisering; trigonometriska momentproblem; optimal masstransport; datortomografi; maskininlärning; analytisk interpolation; system med tidsfördröjning; Mathematics; Matematik;

   Sammanfattning : This thesis, which mainly consists of six appended papers, primarily considers a number of inverse problems in imaging and system identification.In particular, the first two papers generalize results for the rational covariance extension problem from one to higher dimensions. LÄS MER

3. 2. Overcoming the Mass Transport Limitations of Dye-Sensitised Solar Cells : Towards highly efficient and robust alternative redox mediator electrolyte DSSCs

   Författare :Roger Jiang; Gerrit Boschloo; Erik Johansson; Anders Hagfeldt; Frédéric Sauvage; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dye-sensitised solar cell; dye-sensitized solar cell; photoelectrochemical cell; cobalt tris bipyridine ; mass transport; photocurrent transients;

   Sammanfattning : Dye-sensitised solar cells (DSSCs) have been subject to decadelong research interest, and may have some potential niche market applications. Recently, major advances in power conversion efficiencies have been achieved following the transition to cobalt polypyridine based redox mediators. LÄS MER

4. 3. The influence of multiscale hyporheic flow on solute transport : Implications for stream restoration enhancing nitrogen removal

   Författare :Ida Morén; Anders Wörman; Joakim Riml; Roy Haggerty; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Hyporheic exchange flow; Hydrological modeling; Solute transport; Stream restoration; Nitrogen; Power spectral analysis; Hydraulic and Hydrologic Engineering; Hydraulik och teknisk hydrologi;

   Sammanfattning : Stream water that flows into and out of streambeds is called hyporheic exchange flow (HEF).It continuously interacts with groundwater and thereby affect the water quality of local streamreaches as well as downstream recipients by providing an environment where solutes andenergy can be retained and degraded. LÄS MER

5. 4. Integrated brake control : downhill driving strategies

   Författare :Peter Lingman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transport efficiency; heavy duty trucks; road slope estimation; cruise controller; retardation economy; foundation brakes; mass estimation; brake heat fading; Auxilary brakes; downhill driving strategies; component wear;

   Sammanfattning : In this thesis, downhill driving strategies that co–ordinate the different brake actuators in heavy duty vehicles have been developed. As a starting point, the vehicle features affected by the retardation system are investigated. LÄS MER

7. 5. Modeling and Sampling of Spectrally Structured Signals

   Författare :Filip Elvander; Statistical Signal Processing Group; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spectral estimation; parameter estimation; optimal mass transport; covariance interpolation; misspecified models; inharmonicity;

   Sammanfattning : This thesis consists of five papers concerned with the modeling of stochastic signals, as well as deterministic signals in stochastic noise, exhibiting different kinds of structure. This structure is manifested as the existence of finite-dimensional parameterizations, and/or in the geometry of the signals' spectral representations. LÄS MER