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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

FACTS device modelling in the harmonic domain

Collins, Christopher Donald January 2006 (has links)
This thesis describes a novel harmonic domain approach for assessing the steady state performance of Flexible AC Transmission System (FACTS) devices. Existing harmonic analysis techniques are reviewed and used as the basis for a novel iterative harmonic domain model for PWM FACTS devices. The unified Newton formulation adopted uses a combination of positive frequency real valued harmonic and three-phase fundamental frequency power-flow mismatches to characterise a PWM converter system. A dc side mismatch formulation is employed in order to reduce the solution size, something only possible because of the hard switched nature of PWM converters. This computationally efficient formulation permits the study of generalised systems containing multiple FACTS devices. This modular PWM converter block is applied to series, shunt and multi-converter FACTS topologies, with a variety of basic control schemes. Using a three-phase power-flow initialisation and a fixed harmonic Jacobian provides robust convergence to a solution consistent with time domain simulation. By including the power-flow variables in the full harmonic solution the model avoids unnecessary assumptions regarding a fixed (or linearised) operating point, fully modelling system imbalance and the associated non-characteristic harmonics. The capability of the proposed technique is illustrated by considering a range of harmonic interaction mechanisms, both within and between FACTS devices. In particular, the impact of transmission network modelling and operating point variation is investigated with reference to ac and dc side harmonic interaction. The minor role harmonic distortion and over-modulation play in the PWM switching process is finally considered with reference to the associated reduction in system linearity.
52

Med sinne för detaljer : En domänanalytisk studie av ämnet Textilvetenskap vid Uppsala universitet med fokus på föremålsdokumentation / With a sense of details : A study of artifact documentation within the field of Textile Studies at Uppsala University using a Domain analytical framework

Sjöberg, Kristin January 2014 (has links)
The aim of this two year master thesis is to study the knowledge production within the field of Textile Studies at Uppsala University, with special focus on the use of artifact documentation as a research method. With domain analysis as a theoretical framework, ontological and epistemological assumptions as well as historical and social aspects are studied in relation to the research process. Qualitative research methods are used, including interviews, observations and text analysis. In the analysis of the knowledge processes in the field, perspectives on tacit knowledge and the concept of documents, are used as a theoretical basis.   In the field of Textile Studies, the artifacts are used as one of the main objects of study, along with archival and pictorial sources. The main epistemological assumptions are that artifact analysis is dependent on a knowledge base, where technical handicraft skills, contextual knowledge and practical experience of object observation are the most important qualifications. The research process reflects these assumptions, where observation and documentation are used as methods of gaining knowledge.
53

Investigation into performance enhancement of integrated global positioning/inertial navigation systems by frequency domain implementation of inertial computational procedures

Soloviev, Andrey. January 2002 (has links)
Thesis (Ph. D.)--Ohio University, 2002. / Title from PDF t.p.
54

Planar antennas in LTCC technology for ultra-wideband applications /

Brzezina, Grzegorz M., January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 129-136). Also available in electronic format on the Internet.
55

Time-domain simulation of electromagnetic band-gap structures using the TLM method /

Romo Luévano, Gerardo, January 1900 (has links)
Thesis (Ph.D.) - Carleton University, 2005. / Includes bibliographical references (p. 237-249). Also available in electronic format on the Internet.
56

Quantifying the effects of transmitter-receiver geometry variations on the capabilities of airborne electromagnetic survey systems to detect targets of high conductance /

Hefford, Shane W. January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 128-134). Also available in electronic format on the Internet.
57

Via transition modeling and charge replenishment of the power delivery network in multilayer PCBs

Cocchini, Matteo, January 2008 (has links) (PDF)
Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 27, 2008) Includes bibliographical references.
58

Time domain device modeling of High Frequency Power MOSFETs /

Hoagland, Richard W. January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 115-120). Also available via the Internet.
59

Light interaction with human retinal photoreceptor finite-difference time-domain analysis /

Hajiaboli, Amir. January 1900 (has links)
Thesis (Ph.D.). / Written for the Dept. of Electrical & Computer Engineering. Title from title page of PDF (viewed 2009/06/08). Includes bibliographical references.
60

Development of a time domain hybrid finite difference/finite element method for solutions to Maxwell's equations in anisotropic media

Kung, Christopher W., January 2009 (has links)
Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 154-158).

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