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Articles 1 - 9 of 9
Full-Text Articles in Engineering
An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball
An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball
Electrical and Computer Engineering Faculty Research & Creative Works
The Generalized Averaged Modeling (GAM) technique is traditionally employed to capture the dynamic performance of power electronic converters. This paper proposes an improved version of it, named the Extended-GAM (EGAM) technique, which supports the multiplication of two Double Fourier Series (DFS) signals in the time domain. Multiplication of DFS signals in the time domain translates to the 2D-convolution of coefficients of the DFS terms of their equivalent Discrete Fourier Image (DFI) representations. Thus, the proposed EGAM technique, capable of capturing many harmonics present in the output of a power converter, effectively captures the dynamic behavior of power converters excited by …
Chaos-Based Coffee Can Radar System, Conor Willsie, Rong Chen
Chaos-Based Coffee Can Radar System, Conor Willsie, Rong Chen
Honors Theses
Linear frequency modulated (LFM) radar systems are simple and easy to implement, making them ideal for inexpensive undergraduate research projects. Unfortunately, LFM radar schemes have multiple limitations that make them unviable in many real-world applications. Given the limitations of LFM radar systems, we propose a chaos-based frequency modulated (CBFM) system. In this paper, we present the theory, design, and experimental verification of a CBFM radar system that has both ranging and synthetic aperture radar imaging capabilities. The performance of our CBFM system is compared to that of the LFM system designed by MIT. We document many challenges and unforeseen obstacles …
Analog Communication Lab, Yi Sun
Communication Theory, Yi Sun
Theoretical Analysis Of A Volume Holographic Lens Using Matlab, Sanjay Keshri, Kevin Murphy, Izabela Naydenova, Suzanne Martin
Theoretical Analysis Of A Volume Holographic Lens Using Matlab, Sanjay Keshri, Kevin Murphy, Izabela Naydenova, Suzanne Martin
Conference Papers
Volume holographic lenses have great potential for different types of applications requiring light redirection and beam shaping such as solar light collection and LED light management. For lighting applications using LEDs, it is essential to make a highly efficient optical element to be placed in front of the LED in order to decrease energy losses. For that reason, a careful theoretical analysis of the properties and operation regime of the lens must be carried out at the design stage. The characteristics of focusing Holographic Optical Elements (HOE) depend on many factors including their thickness, spatial frequency, the angular range of …
Inter-Joint Coordination Deficits Revealed In The Decomposition Of Endpoint Jerk During Goal-Directed Arm Movement After Stroke, Jozsef Laczko, Robert A. Scheidt, Lucia Simo, Davide Piovesan
Inter-Joint Coordination Deficits Revealed In The Decomposition Of Endpoint Jerk During Goal-Directed Arm Movement After Stroke, Jozsef Laczko, Robert A. Scheidt, Lucia Simo, Davide Piovesan
Biomedical Engineering Faculty Research and Publications
It is well documented that neurological deficits after stroke can disrupt motor control processes that affect the smoothness of reaching movements. The smoothness of hand trajectories during multi-joint reaching depends on shoulder and elbow joint angular velocities and their successive derivatives as well as on the instantaneous arm configuration and its rate of change. Right-handed survivors of unilateral hemiparetic stroke and neurologically-intact control participants held the handle of a two-joint robot and made horizontal planar reaching movements. We decomposed endpoint jerk into components related to shoulder and elbow joint angular velocity, acceleration, and jerk. We observed an abnormal decomposition pattern …
Fm Demodulators In Software-Defined Radio Using Fpgas With Rapid Prototyping, Marc Anthony Padilla
Fm Demodulators In Software-Defined Radio Using Fpgas With Rapid Prototyping, Marc Anthony Padilla
Theses and Dissertations
With the advent of software-defined radio, many radio applications have and are currently being designed for FPGAs, due to their high performance and reconfigurability. Invariably, "legacy" waveforms, such as FM, will need to be supported in such systems. A challenge that comes with programming FPGAs is the increased design and implementation time over conventional software programming. In this thesis, three FM demodulator techniques are implemented and compared in an FPGA. Two techniques are found to have similar SNR performance while having very different FPGA implementation characteristics. Library based design is explored for demodulators to increase FPGA design productivity. A block …
Multicore, Multithreaded, Phase-Synchronous Fm Sound Synthesizer, Justin Tomlin
Multicore, Multithreaded, Phase-Synchronous Fm Sound Synthesizer, Justin Tomlin
Electrical Engineering
This project implements a phase-synchronous FM synthesis algorithm in hardware. Envelope and low frequency oscillator modulation of oscillator parameters is implemented. The microcontroller the system is based on, the XMOS XS1-G4, allows for physical parallelism including features such as multiple cores, multiple hardware threads on each core, a hardware event-driven thread scheduler, and channel, channel ends, and link switches for thread and core communication. The event-driven architecture of this device was ideal for implementing this synthesis algorithm. The final product is portable, durable, has a simple, intuitive user interface, and allows for extensive spectral shaping capabilities. The basic functional requirements …
Impact Of Local Attenuation Approximations When Estimating Correlation Length From Backscattered Ultrasound Echoes, Timothy A. Bigelow, William D. O'Brien
Impact Of Local Attenuation Approximations When Estimating Correlation Length From Backscattered Ultrasound Echoes, Timothy A. Bigelow, William D. O'Brien
Timothy A. Bigelow
Estimating the characteristic correlation length of tissue microstructure from the backscattered power spectrum could improve the diagnostic capability of medical ultrasound. Previously, size estimates were obtained after compensating for source focusing, the frequency-dependent attenuation along the propagation path (total attenuation), and the frequency-dependent attenuation in the scattering region (local attenuation). In this study, the impact of approximations of the local attenuation on the scatterer size estimate was determined using computer simulations and theoretical analysis. The simulations used Gaussian impedance distributions with an effective radius of 25 μm randomly positioned in a homogeneous half-space sonified by a spherically focused source (f/1 …