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- Creators: Barrett, The Honors College
- Resource Type: Text
Description
Lossy compression is a form of compression that slightly degrades a signal in ways that are ideally not detectable to the human ear. This is opposite to lossless compression, in which the sample is not degraded at all. While lossless compression may seem like the best option, lossy compression, which is used in most audio and video, reduces transmission time and results in much smaller file sizes. However, this compression can affect quality if it goes too far. The more compression there is on a waveform, the more degradation there is, and once a file is lossy compressed, this process is not reversible. This project will observe the degradation of an audio signal after the application of Singular Value Decomposition compression, a lossy compression that eliminates singular values from a signal’s matrix.
ContributorsHirte, Amanda (Author) / Kosut, Oliver (Thesis director) / Bliss, Daniel (Committee member) / Electrical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This dissertation proposes a miniature FIR filter that works at microwave frequencies, whose filter response can ideally be digitally programmed. Such a frequency agile device can find applications in cellular communications and wireless networking. The basic concept of the FIR filter utilizes a low loss acoustic waveguide of appropriate geometry that acts as a traveling wave tapped-delay line. The input RF signal is applied by an array of capacitive transducers at various locations on the acoustic waveguide at one end that excites waves of a propagating acoustic mode with varying spatial delays and amplitudes which interfere as they propagate. The output RF signal is picked up at the other end of the waveguide by another array of capacitive transducers. Tuning of the FIR filter coefficients is realized by controlling the DC voltage profile applied to the individual transducers which essentially shapes the overall filter response. Equivalent circuit modeling of the capacitive transducer, acoustic waveguide and transducer-line coupling is presented in this dissertation. A theoretical model for the filter is developed from a general theory of an array of transducers exciting a waveguide and is used to obtain a set of filter design equations. A MATLAB based circuit simulator is developed to simulate the filter responses. Design parameters and simulation results obtained for an example waveguide structure are presented and compared to the values estimated by the theoretical model. A waveguide structure utilizing the Rayleigh-like mode of a ridge is then introduced. A semi-analytical method to obtain propagating elastic modes of such a ridge waveguide etched in an anisotropic crystal is presented. Microfabrication of a filter based on ridges etched in single crystal Silicon is discussed along with details of the challenges faced. Finally, future work and a few alternative designs are presented that can have a better chance of success. Analysis and modeling work to this point has given a good understanding of the working principles, performance tradeoffs and fabrication pitfalls of the proposed device. With the appropriate acoustic waveguide structure, the proposed device could make it possible to realize miniature programmable FIR filters in the GHz range.
ContributorsGalinde, Ameya (Author) / Abbaspour-Tamijani, Abbas (Thesis advisor) / Chae, Junseok (Committee member) / Pan, George (Committee member) / Phillips, Stephen (Committee member) / Arizona State University (Publisher)
Created2013
Description
Power supply management is important for MEMS (Micro-Electro-Mechanical-Systems) bio-sensing and chemical sensing applications. The dissertation focuses on discussion of accessibility to different power sources and supply tuning in sensing applications. First, the dissertation presents a high efficiency DC-DC converter for a miniaturized Microbial Fuel Cell (MFC). The miniaturized MFC produces up to approximately 10µW with an output voltage of 0.4-0.7V. Such a low voltage, which is also load dependent, prevents the MFC to directly drive low power electronics. A PFM (Pulse Frequency Modulation) type DC-DC converter in DCM (Discontinuous Conduction Mode) is developed to address the challenges and provides a load independent output voltage with high conversion efficiency. The DC-DC converter, implemented in UMC 0.18µm technology, has been thoroughly characterized, coupled with the MFC. At 0.9V output, the converter has a peak efficiency of 85% with 9µW load, highest efficiency over prior publication. Energy could be harvested wirelessly and often has profound impacts on system performance. The dissertation reports a side-by-side comparison of two wireless and passive sensing systems: inductive and electromagnetic (EM) couplings for an application of in-situ and real-time monitoring of wafer cleanliness in semiconductor facilities. The wireless system, containing the MEMS sensor works with battery-free operations. Two wireless systems based on inductive and EM couplings have been implemented. The working distance of the inductive coupling system is limited by signal-to-noise-ratio (SNR) while that of the EM coupling is limited by the coupled power. The implemented on-wafer transponders achieve a working distance of 6 cm and 25 cm with a concentration resolution of less than 2% (4 ppb for a 200 ppb solution) for inductive and EM couplings, respectively. Finally, the supply tuning is presented in bio-sensing application to mitigate temperature sensitivity. The FBAR (film bulk acoustic resonator) based oscillator is an attractive method in label-free sensing application. Molecular interactions on FBAR surface induce mass change, which results in resonant frequency shift of FBAR. While FBAR has a high-Q to be sensitive to the molecular interactions, FBAR has finite temperature sensitivity. A temperature compensation technique is presented that improves the temperature coefficient of a 1.625 GHz FBAR-based oscillator from -118 ppm/K to less than 1 ppm/K by tuning the supply voltage of the oscillator. The tuning technique adds no additional component and has a large frequency tunability of -4305 ppm/V.
ContributorsZhang, Xu (Author) / Chae, Junseok (Thesis advisor) / Kiaei, Sayfe (Committee member) / Bakkaloglu, Bertan (Committee member) / Kozicki, Michael (Committee member) / Phillips, Stephen (Committee member) / Arizona State University (Publisher)
Created2012
Description
The world of a hearing impaired person is much different than that of somebody capable of discerning different frequencies and magnitudes of sound waves via their ears. This is especially true when hearing impaired people play video games. In most video games, surround sound is fed through some sort of digital output to headphones or speakers. Based on this information, the gamer can discern where a particular stimulus is coming from and whether or not that is a threat to their wellbeing within the virtual world. People with reliable hearing have a distinct advantage over hearing impaired people in the fact that they can gather information not just from what is in front of them, but from every angle relative to the way they're facing. The purpose of this project was to find a way to even the playing field, so that a person hard of hearing could also receive the sensory feedback that any other person would get while playing video games To do this, visual surround sound was created. This is a system that takes a surround sound input, and illuminates LEDs around the periphery of glasses based on the direction, frequency and amplitude of the audio wave. This provides the user with crucial information on the whereabouts of different elements within the game. In this paper, the research and development of Visual Surround Sound is discussed along with its viability in regards to a deaf person's ability to learn the technology, and decipher the visual cues.
ContributorsKadi, Danyal (Co-author) / Burrell, Nathaneal (Co-author) / Butler, Kristi (Co-author) / Wright, Gavin (Co-author) / Kosut, Oliver (Thesis director) / Bliss, Daniel (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2015-05
Description
The purpose of the solar powered quadcopter is to join together the growing technologies of photovoltaics and quadcopters, creating a single unified device where the technologies harmonize to produce a new product with abilities beyond those of a traditional battery powered drone. Specifically, the goal is to take the battery-only flight time of a quadcopter loaded with a solar array and increase that flight time by 33% with additional power provided by solar cells. The major concepts explored throughout this project are quadcopter functionality and capability and solar cell power production. In order to combine these technologies, the solar power and quadcopter components were developed and analyzed individually before connecting the solar array to the quadcopter circuit and testing the design as a whole. Several solar copter models were initially developed, resulting in multiple unique quadcopter and solar cell array designs which underwent preliminary testing before settling on a finalized design which proved to be the most effective and underwent final timed flight tests. Results of these tests are showing that the technologies complement each other as anticipated and highlight promising results for future development in this area, in particular the development of a drone running on solar power alone. Applications for a product such as this are very promising in many fields, including the industries of power, defense, consumer goods and services, entertainment, marketing, and medical. Also, becoming a more popular device for UAV hobbyists, such developments would be very appealing for leisure flying and personal photography purposes as well.
ContributorsMartin, Heather Catrina (Author) / Bowden, Stuart (Thesis director) / Aberle, James (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
The apparent phenomenon of the human eye retaining images for fractions of a second after the light source has gone is known as Persistence of Vision. While its causes are not fully understood, it can be taken advantage of in order to create illusions which trick the mind into perceiving something which, in actuality, is very different from what the mind portrays. It has motivated many creative engineering technologies in the past and is the core for how we perceive motion in movies and animations. This project applies the persistence of vision concept to a lesser explored medium; the wheel of a moving bicycle. The motion of the wheel, along with intelligent control of discrete LEDs, create vibrant illusions of solid lines and shapes. These shapes make up the image to be displayed on the bike wheel. The rotation of the bike wheel can be compensated for in order to produce a standing image (or images) of the user's choosing. This thesis details how the mechanism for conducting the individual LEDs was created in order to produce a device which is capable of delivering colorful, standing images of the user's choosing.
ContributorsSaltwick, Ian Mark (Author) / Goryll, Michael (Thesis director) / Kozicki, Michael (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
This project was centered around designing a processor model (using the C programming language) based on the Coldfire computer architecture that will run on third party software known as Open Virtual Platforms. The end goal is to have a fully functional processor that can run Coldfire instructions and utilize peripheral devices in the same way as the hardware used in the embedded systems lab at ASU. This project would cut down the substantial amount of time students spend commuting to the lab. Having the processor directly at their disposal would also encourage them to spend more time outside of class learning the hardware and familiarizing themselves with development on an embedded micro-controller. The model will be accurate, fast and reliable. These aspects will be achieved through rigorous unit testing and use of the OVP platform which provides instruction accurate simulations at hundreds of MIPS (million instructions per second) for the specified model. The end product was able to accurately simulate a subset of the Coldfire instructions at very high rates.
ContributorsDunning, David Connor (Author) / Burger, Kevin (Thesis director) / Meuth, Ryan (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2014-12
Description
Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the use of high voltage arcs to produce audible sound amplification. The goal of the project is to prove feasibility that a consumer grade plasma arc speaker could exist in the marketplace. The inherent challenge was producing audio amplification that could compete with current loudspeakers all while ensuring user safety from the hazards of high voltage and current shock, electromagnetic damage, and ozone from the plasma arc. The project has thus far covered the process of design conception to realization of a prototype device. The operation of the plasma arc speaker is based on the high voltage plasma arc created between two electrodes. The plasma arc rapidly heats and cools the surrounding air creating changes in air pressure which vibrate the air. These pockets of pressurized air are heard as sound. The circuit incorporates a flyback transformer responsible for creating the high voltage necessary for arcing.
ContributorsNandan, Rahul S (Author) / Roedel, Ronald (Thesis director) / Huffman, James (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
Description
Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the use of high voltage arcs to produce audible sound amplification. The goal of the project is to prove feasibility that a consumer grade plasma arc speaker could exist in the marketplace. The inherent challenge was producing audio amplification that could compete with current loudspeakers all while ensuring user safety from the hazards of high voltage and current shock, electromagnetic damage, and ozone from the plasma arc. The project has thus far covered the process of design conception to realization of a prototype device. The operation of the plasma arc speaker is based on the high voltage plasma arc created between two electrodes. The plasma arc rapidly heats and cools the surrounding air creating changes in air pressure which vibrate the air. These pockets of pressurized air are heard as sound. The circuit incorporates a flyback transformer responsible for creating the high voltage necessary for arcing.
ContributorsNandan, Rahul S (Author) / Roedel, Ronald (Thesis director) / Huffman, James (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2014-05
Description
There is an interest in citizen scientist networks such as CoCoRaHS to develop an air temperature sensor with a solar shield that is both extremely low cost and user friendly for use in widespread data collection in order to analyze urban microclimates. This paper outlines work done to develop a low cost micrometeorology instrument to fulfill the design requirements set by CoCoRaHS. While the first two revisions of this technology had significant changes in development, a third revision was created as a proof of concept that low cost temperature sensors could be used in an array to accurately measure air temperature without solar radiation interference. Another technology, described as revision four, called the iButton was also evaluated and displayed promising ability to log temperatures, but costs too much for the ultra-low cost design goal. Additionally, work was done to design a radiation shield that will be prototyped and tested alongside commercial radiation shields. This controlled experiment will also include further evaluation of the iButton and the next revision of a custom microclimate temperature sensing unit to determine the best option for widespread field testing.
ContributorsMarshall, Travis Keith (Author) / Jordan, Shawn (Thesis director) / Ruddell, Benjamin (Committee member) / Barrett, The Honors College (Contributor) / Department of Engineering (Contributor)
Created2014-05