Search for dissertations about: "correlated systems"

Showing result 1 - 5 of 513 swedish dissertations containing the words correlated systems.

  1. 1. Correlated materials : models and methods

    Author : Hugo Strand; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; correlated electrons; Hubbard model; multiband Hubbard model; dynamical mean field theory; exact diagonalization; Landau theory; Mott metal-insulator transition; Gutzwiller method; many-body point group symmetry; ironchalcogenides; Kanamori interaction; Slater-Condon interaction;

    Abstract : This thesis encompass a series of studies on methods and models for electron systems with local interactions, relevant for correlated materials. The first study focus on the canonical model for local correlation, the Hubbard model. READ MORE

  2. 2. Residential Demand Response in the Context of European Union Energy Policy

    Author : Pia Stoll; Fredrik Gröndahl; Nils Brandt; Lars Nordström; Will Kling; KTH; []

    Abstract : In order to achieve energy security, reduce global warming and promote the vision of a common electricity market, the European Union (EU) is transforming the EU electricity grid from a large set of independent hierarchical national grids into one meshed EU-wide grid. For the first time in the history of the electric power industry, residential consumers are being integrated into the grid as active consumers and micro-generators of electricity. READ MORE

  3. 3. On MIMO Systems and Adaptive Arrays for Wireless Communication : Analysis and Practical Aspects

    Author : Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Systemteknik; antenna array; calibration; MIMO system; flat fading; non-linear amplifier; switched parasitic antenna; analog beamformer; adaptive antenna testbed; Systemteknik; Systems engineering; Systemteknik; Signal Processing; signalbehandling;

    Abstract : This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). READ MORE

  4. 4. Quantifying human balance : Analysis of force plate data

    Author : Annica Önell; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Systems engineering; Systemteknik; Systemanalys; Systems Analysis;

    Abstract : There is a lack of reliable methods for assessment of balance suited for routine use in clinical settings. The thesis focuses on analysis of force plate data for evaluation of balance during normal, unperturbed standing and sitting. Some commonly used force plate based methods during unperturbed standing are presented. READ MORE

  5. 5. HARQ Systems: Resource Allocation, Feedback Error Protection, and Bits-to-Symbol Mappings

    Author : Chaitanya Tumula V. K.; Erik G. Larsson; Danyo Danev; Ana I. Pérez-Neira; Linköpings universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HARQ Systems; Resource Allocation; Geometric Programming; 3GPP-LTE; PUCCH Format 2; Complex-field coding; Signal Space Diversity; Optimization; Superposition Coding;

    Abstract : Reliability of data transmission is a fundamental problem in wireless communications. Fading in wireless channels causes the signal strength to vary at the receiver and this results in loss of data packets. To improve the reliability, automatic repeat request (ARQ) schemes were introduced. READ MORE