Sökning: "Multilevel"

Visar resultat 36 - 40 av 251 avhandlingar innehållade ordet Multilevel.

  1. 36. Modulation of Modular Multilevel Converters for HVDC Transmission

    Författare :Arman Hassanpoor; Hans-Peter Nee; Staffan Norrga; Rainer Marquardt; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; switching schemes; modulation; high power converters; power grids; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The outstanding features of modular multilevel converters (MMC) have recently gained much attention in the high-voltage direct-current (HVDC) transmission field. Power quality, converter cost and system performance are three crucial aspects of HVDC MMCs which are directly linked to the converter modulation and switching schemes. LÄS MER

  3. 37. Multiscale and multilevel methods for porous media flow problems

    Författare :Fredrik Hellman; Axel Målqvist; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : We consider two problems encountered in simulation of fluid flow through porous media. In macroscopic models based on Darcy's law, the permeability field appears as data.The first problem is that the permeability field generally is not entirely known. LÄS MER

  4. 38. Battery Integrated Modular Multilevel Converter Topologies for Automotive Applications

    Författare :Arvind Balachandran; Lars Eriksson; Tomas Uno Jonsson; Torbjörn Thiringer; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Electric vehicles are rapidly developing in response to the need for increasing sustainable energy sources. The range and lifetime of an electric vehicle are limited by the battery pack. A pack comprises modules with several parallel and/or series-connected cells. LÄS MER

  5. 39. On Linguistic and Discursive Constructions of Concession and Adversativity : Towards a Multilevel Analysis of English in the UK Parliament

    Författare :Mihai Daniel Frumuselu; Michal Krzyżanowski; Cornelia Ilie; Per Ledin; Eivind Nessa Torgersen; Örebro universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; concession; adversativity; political discourse; parliamentary discourse; UK Parliament; Corpus Linguistics; Discourse Analysis; Critical Discourse Analysis; English; Engelska;

    Sammanfattning : This study analyses concessive and adversarial language in UK parliamentary debates and thereby enriches the theoretical and analytical body of knowledge on the language of concession and adversativity in contemporary English. It contributes to existent scholarship on both grammatical constructions of concession/adversativity and on the dynamics of contemporary British parliamentary and political discourse. LÄS MER

  7. 40. Channel-Aware Multilevel Coded Modulation for Coherent Fiber-Optic Communications

    Författare :Lotfollah Beygi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel model; multidimensional set partitioning; low-complexity de- tector; coded modulation; signal statistics.; nonlinear phase noise; Fiber-optic communications;

    Sammanfattning : The past decades have shown an ever-increasing demand for high-rate Internet services, motivating a great effort to increase the spectral efficiency of optical networks. In general, fiber-optic links are non-Gaussian, and in contrast to additive white Gaussian noise (AWGN) channels, there is no standard framework for quantifying fundamental limits or designing capacity-approaching coding schemes for such channels. LÄS MER