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Single echo acquisition magnetic resonance imagingMcDougall, Mary Preston 12 April 2006 (has links)
The dramatic improvement in magnetic resonance imaging (MRI) scan time over the past fifteen years through gradient-based methods that sample k-space more efficiently and quickly cannot be sustained, as thresholds regarding hardware and safety limitations are already being approached. Parallel imaging methods (using multiple receiver coils to partially encode k-space) have offered some relief in the efforts and are rapidly becoming the focus of current endeavors to decrease scan time. Ideally, for some applications, phase encoding would be eliminated completely, replaced with array coil encoding instead, and the entire image formed in a single echo.
The primary objective of this work was to explore that acceleration limit  to implement and investigate the methodology of single echo acquisition magnetic resonance imaging (SEA MRI). The initial evaluation of promising array coil designs is described, based on parameters determined by the ability to enable the imaging method. The analyses of field patterns, decoupling, and signal-to-noise ratio (SNR) that led to the final 64-channel array coil design are presented, and the fabrication and testing of coils designed for 4.7T and 1.5T are described. A detailed description of the obtainment of the first SEA images  64xNreadout images, acquired in a single echo  is provided with an evaluation of those images and highly accelerated images (through parallel imaging techniques) based on SNR and artifact power. Finally, the development of methodologies for various MR applications is described: applications that would particularly benefit from the speed of the imaging method, or those to which the method or the tool (array coil) lends itself. These applications include, but are not limited to, 3D imaging (phase encode in the slice select direction), resolution-enhanced imaging, large-scale (field-of-view) microscopy, and conformal surface imaging. Finally, using the primary enablement of the method  the ability to obtain complete MR images at speeds limited only by the time it takes to acquire a single echo  is presented with a discussion of extremely high frame rate imaging.
The contribution to the field of medical imaging is the first implementation, characterization, and demonstration of applications for the acquisition of MR images in a single echo.
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Alternatives Antriebs-und Auswerteverfahren für die MikrosystemtechnikBuschnakowski, Stephan 15 November 2004 (has links) (PDF)
In this paper the development, the fabrication and the experimental characterisation of a novel electrodynamic-driven micro-actuator for in plane motions and a novel vertical field effect transistor (vertical FET) is presented.
The micro-actuator for motion is based on the Lorentz force generated by a current in a magnetic field. The Lorentz force acting on the actuator can be controlled easily by the amplitude of the current.
The vertical FET can be used for signal conversion from the mechanical to the electrical domain. This low impedance sensing technique was realized by introducing a source and drain region in opposite of a movable mass which acts as the gate. The channel resistance between drain and source is influenced by the movable mass working as a sensing unit. Theoretical calculations and practical experiments of the structure are performed. Mechanical and electrical effects over a temperature range of -40 °C to 180 °C are investigated. / In dieser Arbeit wird ein neues Aktorarray zur Objektmanipulation und ein neues Verfahren zur Detektion mechanischer Bewegung in Komponenten der oberflächennahen Bulk-Mikromechanik vorgestellt. Die Aktorstrukturen werden mit Hilfe der SCREAM-Technologie hergestellt und arbeiten nach dem elektrodynamischen Wirkprinzip. Bei dem Verfahren zur Bewegungsdetektion wird der aus der Mikroelektronik bekannte Feldeffekt mit mikromechanischen Strukturen gekoppelt.
Die Arbeit konzentriert sich auf den Aufbau, die Wirkungsweise und die Technologie der Aktor- und Sensorstrukturen. Diese werden jeweils separat dargestellt und analysiert. Am Ende wird eine Kombination beider Komponenten vorgestellt.
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A Verilog 8051 soft core for FPGA applicationsRangoonwala, Sakina. Kougianos, Elias, January 2009 (has links)
Thesis (M.S.)--University of North Texas, August, 2009. / Title from title page display. Includes bibliographical references.
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Efficient elliptic curve processor architectures for field programmable logicOrlando, Gerardo. January 2002 (has links)
Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: computer arithmetic; elliptic curves; cryptography. Includes bibliographical references (p. 299-305).
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Geotextile antenna design for mobile phone cooperative communication relay nodeLi, Houmin, Thomas, Gwynedd A. January 2008 (has links)
Thesis--Auburn University, 2008. / Abstract. Vita. Includes bibliographic references (p.65-67).
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Source level debugging of circuits synthesized from high level language descriptions /Hemmert, Karl S., January 2004 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 143-149).
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Transmission strategies for wireless multi-user, multiple-input, multiple-output communication channels /Spencer, Quentin H., January 2004 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 129-145).
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Acceleration of streaming applications on FPGAs from high level constructsMitra, Abhishek. January 2008 (has links)
Thesis (Ph. D.)--University of California, Riverside, 2008. / Includes abstract. Title from first page of PDF file (viewed March 8, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 150-168). Also issued in print.
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Testing and evaluation of the configurable fault tolerant processor (CFTP) for space-based application /Hulme, Charles A. January 2003 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Herschel H. Loomis, Jr., Alan A. Ross. Includes bibliographical references (p. 241-243). Also available online.
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Achieving near-optimal MIMO capacity in a rank-deficient LOS environmentWalkenhorst, Brett T. January 2009 (has links)
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Ingram, Mary Ann; Committee Member: Durgin, Greg; Committee Member: Kenney, Steve; Committee Member: Landgren, Jack; Committee Member: Li, Ye. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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