Sökning: "spectral shaping"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden spectral shaping.

  1. 1. Inverse Problems in Analytic Interpolation for Robust Control and Spectral Estimation

    Författare :Johan Karlsson; Anders Lindquist; Alberto Isidori; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Nevanlinna-Pick Interpolation; Approximation; Model Reduction; Robust Control; Gap-robustness; Sensitivity Shaping; Entropy functional; Spectral Estimation; Weak*-topology; Monge-Kantorovic Transportation; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : This thesis is divided into two parts. The first part deals with theNevanlinna-Pick interpolation problem, a problem which occursnaturally in several applications such as robust control, signalprocessing and circuit theory. We consider the problem of shaping andapproximating solutions to the Nevanlinna-Pick problem in a systematicway. LÄS MER

  3. 2. Measurement and Control of Attosecond Light Fields

    Författare :Erik Mansten; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Pulse characterization; Spectral signature; Two-color generation; Pulse compression; Attosecond pulse trains; High-order harmonics; Pulse shaping; Tunable; Fysicumarkivet A:2009:Mansten;

    Sammanfattning : Attosecond pulses are used to study electron dynamics in atoms and molecules. In this thesis, schemes to control the generation of attosecond pulses and pulse-shaping techniques to compress the pulses are presented. Generation of attosecond pulses requires high intensity, which is reached by focusing a pulsed femtosecond laser. LÄS MER

  4. 3. On Probabilistic Shaping and Learned Decoders with Application to Fiber-Optic Communications

    Författare :Andreas Buchberger; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Error correcting codes; probabilistic shaping; pruning; fiber-optic communications; machine learning; learned decoders; iterative decoding;

    Sammanfattning : We live in an ubiquitously connected world whose backbone are optical fibers. Achieving high spectral efficiencies and hence high transmission rates requires a careful combination of forward error correction (FEC) and higher-order modulation. This is referred to as coded modulation. LÄS MER

  5. 4. Spectral Mammography with X-Ray Optics and a Photon-Counting Detector

    Författare :Erik Fredenberg; Mats Danielsson; Björn Cederström; Jeffrey H. Siewerdsen; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; MEDICIN OCH HÄLSOVETENSKAP; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; MEDICAL AND HEALTH SCIENCES; mammography; x-ray optics; photon counting; spectral shaping; spectral imaging; collimation; radiation dose; signal-to-noise ratio; quantum noise; anatomical noise; spatial resolution; x-ray flux; ; TECHNOLOGY; TEKNIKVETENSKAP; Engineering physics; Teknisk fysik; Optical physics; Optisk fysik; Other engineering physics; Övrig teknisk fysik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Medical engineering; Medicinsk teknik; Radiological research; Radiologisk forskning;

    Sammanfattning : Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. LÄS MER

  7. 5. Modeling and Model Reduction by Analytic Interpolation and Optimization

    Författare :Giovanna Fanizza; Anders Lindquist; György Michaletzky; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Analytic Interpolation theory with a degree constraint; rational covariance extension problem; spectral estimation; model reduction; optimization; passive system; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : This thesis consists of six papers. The main topic of all these papers is modeling a class of linear time-invariant systems. The system class is parameterized in the context of interpolation theory with a degree constraint. LÄS MER