Matching Items (61)
Filtering by
- All Subjects: Creative Project
- All Subjects: Electrical Engineering
Description
Sliding-Mode Control (SMC) has several benefits over traditional Proportional-Integral-Differential (PID) control in terms of fast transient response, robustness to parameter and component variations, and low sensitivity to loop disturbances. An All-Digital Sliding-Mode (ADSM) controlled DC-DC converter, utilizing single-bit oversampled frequency domain digitizers is proposed. In the proposed approach, feedback and reference digitizing Analog-to-Digital Converters (ADC) are based on a single-bit, first order Sigma-Delta frequency to digital converter, running at 32MHz over-sampling rate. The ADSM regulator achieves 1% settling time in less than 5uSec for a load variation of 600mA. The sliding-mode controller utilizes a high-bandwidth hysteretic differentiator and an integrator to perform the sliding control law in digital domain. The proposed approach overcomes the steady state error (or DC offset), and limits the switching frequency range, which are the two common problems associated with sliding-mode controllers. The IC is designed and fabricated on a 0.35um CMOS process occupying an active area of 2.72mm-squared. Measured peak efficiency is 83%.
ContributorsDashtestani, Ahmad (Author) / Bakkaloglu, Bertan (Thesis advisor) / Thornton, Trevor (Committee member) / Song, Hongjiang (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
Feature representations for raw data is one of the most important component in a machine learning system. Traditionally, features are \textit{hand crafted} by domain experts which can often be a time consuming process. Furthermore, they do not generalize well to unseen data and novel tasks. Recently, there have been many efforts to generate data-driven representations using clustering and sparse models. This dissertation focuses on building data-driven unsupervised models for analyzing raw data and developing efficient feature representations.
Simultaneous segmentation and feature extraction approaches for silicon-pores sensor data are considered. Aggregating data into a matrix and performing low rank and sparse matrix decompositions with additional smoothness constraints are proposed to solve this problem. Comparison of several variants of the approaches and results for signal de-noising and translocation/trapping event extraction are presented. Algorithms to improve transform-domain features for ion-channel time-series signals based on matrix completion are presented. The improved features achieve better performance in classification tasks and in reducing the false alarm rates when applied to analyte detection.
Developing representations for multimedia is an important and challenging problem with applications ranging from scene recognition, multi-media retrieval and personal life-logging systems to field robot navigation. In this dissertation, we present a new framework for feature extraction for challenging natural environment sounds. Proposed features outperform traditional spectral features on challenging environmental sound datasets. Several algorithms are proposed that perform supervised tasks such as recognition and tag annotation. Ensemble methods are proposed to improve the tag annotation process.
To facilitate the use of large datasets, fast implementations are developed for sparse coding, the key component in our algorithms. Several strategies to speed-up Orthogonal Matching Pursuit algorithm using CUDA kernel on a GPU are proposed. Implementations are also developed for a large scale image retrieval system. Image-based "exact search" and "visually similar search" using the image patch sparse codes are performed. Results demonstrate large speed-up over CPU implementations and good retrieval performance is also achieved.
Simultaneous segmentation and feature extraction approaches for silicon-pores sensor data are considered. Aggregating data into a matrix and performing low rank and sparse matrix decompositions with additional smoothness constraints are proposed to solve this problem. Comparison of several variants of the approaches and results for signal de-noising and translocation/trapping event extraction are presented. Algorithms to improve transform-domain features for ion-channel time-series signals based on matrix completion are presented. The improved features achieve better performance in classification tasks and in reducing the false alarm rates when applied to analyte detection.
Developing representations for multimedia is an important and challenging problem with applications ranging from scene recognition, multi-media retrieval and personal life-logging systems to field robot navigation. In this dissertation, we present a new framework for feature extraction for challenging natural environment sounds. Proposed features outperform traditional spectral features on challenging environmental sound datasets. Several algorithms are proposed that perform supervised tasks such as recognition and tag annotation. Ensemble methods are proposed to improve the tag annotation process.
To facilitate the use of large datasets, fast implementations are developed for sparse coding, the key component in our algorithms. Several strategies to speed-up Orthogonal Matching Pursuit algorithm using CUDA kernel on a GPU are proposed. Implementations are also developed for a large scale image retrieval system. Image-based "exact search" and "visually similar search" using the image patch sparse codes are performed. Results demonstrate large speed-up over CPU implementations and good retrieval performance is also achieved.
ContributorsSattigeri, Prasanna S (Author) / Spanias, Andreas (Thesis advisor) / Thornton, Trevor (Committee member) / Goryll, Michael (Committee member) / Tsakalis, Konstantinos (Committee member) / Arizona State University (Publisher)
Created2014
Description
The first part describes Metal Semiconductor Field Effect Transistor (MESFET) based fundamental analog building blocks designed and fabricated in a single poly, 3-layer metal digital CMOS technology utilizing fully depletion mode MESFET devices. DC characteristics were measured by varying the power supply from 2.5V to 5.5V. The measured DC transfer curves of amplifiers show good agreement with the simulated ones with extracted models from the same process. The accuracy of the current mirror showing inverse operation is within ±15% for the current from 0 to 1.5mA with the power supply from 2.5 to 5.5V. The second part presents a low-power image recognition system with a novel MESFET device fabricated on a CMOS substrate. An analog image recognition system with power consumption of 2.4mW/cell and a response time of 6µs is designed, fabricated and characterized. The experimental results verified the accuracy of the extracted SPICE model of SOS MESFETs. The response times of 4µs and 6µs for one by four and one by eight arrays, respectively, are achieved with the line recognition. Each core cell for both arrays consumes only 2.4mW. The last part presents a CMOS low-power transceiver in MICS band is presented. The LNA core has an integrated mixer in a folded configuration. The baseband strip consists of a pseudo differential MOS-C band-pass filter achieving demodulation of 150kHz-offset BFSK signals. The SRO is used in a wakeup RX for the wake-up signal reception. The all digital frequency-locked loop drives a class AB power amplifier in a transmitter. The sensitivity of -85dBm in the wakeup RX is achieved with the power consumption of 320µW and 400µW at the data rates of 100kb/s and 200kb/s from 1.8V, respectively. The sensitivities of -70dBm and -98dBm in the data-link RX are achieved with NF of 40dB and 11dB at the data rate of 100kb/s while consuming only 600µW and 1.5mW at 1.2V and 1.8V, respectively.
ContributorsKim, Sung (Author) / Bakkaloglu, Bertan (Thesis advisor) / Christen, Jennifer Blain (Committee member) / Cao, Yu (Committee member) / Thornton, Trevor (Committee member) / Arizona State University (Publisher)
Created2011
Description
The high cut-off frequency of deep sub-micron CMOS technologies has enabled the integration of radio frequency (RF) transceivers with digital circuits. However, the challenging point is the integration of RF power amplifiers, mainly due to the low breakdown voltage of CMOS transistors. Silicon-on-insulator (SOI) metal semiconductor field effect transistors (MESFETs) have been introduced to remedy the limited headroom concern in CMOS technologies. The MESFETs presented in this thesis have been fabricated on different SOI-CMOS processes without making any change to the standard fabrication steps and offer 2-30 times higher breakdown voltage than the MOSFETs on the same process. This thesis explains the design steps of high efficiency and wideband RF transmitters using the proposed SOI-CMOS compatible MESFETs. This task involves DC and RF characterization of MESFET devices, along with providing a compact Spice model for simulation purposes. This thesis presents the design of several SOI-MESFET RF power amplifiers operating at 433, 900 and 1800 MHz with ~40% bandwidth. Measurement results show a peak power added efficiency (PAE) of 55% and a peak output power of 22.5 dBm. The RF-PAs were designed to operate in Class-AB mode to minimize the linearity degradation. Class-AB power amplifiers lead to poor power added efficiency, especially when fed with signals with high peak to average power ratio (PAPR) such as wideband code division multiple access (W-CDMA). Polar transmitters have been introduced to improve the efficiency of RF-PAs at backed-off powers. A MESFET based envelope tracking (ET) polar transmitter was designed and measured. A low drop-out voltage regulator (LDO) was used as the supply modulator of this polar transmitter. MESFETs are depletion mode devices; therefore, they can be configured in a source follower configuration to have better stability and higher bandwidth that MOSFET based LDOs. Measurement results show 350 MHz bandwidth while driving a 10 pF capacitive load. A novel polar transmitter is introduced in this thesis to alleviate some of the limitations associated with polar transmitters. The proposed architecture uses the backgate terminal of a partially depleted transistor on SOI process, which relaxes the bandwidth and efficiency requirements of the envelope amplifier in a polar transmitter. The measurement results of the proposed transmitter demonstrate more than three times PAE improvement at 6-dB backed-off output power, compared to the traditional RF transmitters.
ContributorsGhajar, Mohammad Reza (Author) / Thornton, Trevor (Thesis advisor) / Aberle, James T., 1961- (Committee member) / Bakkaloglu, Bertan (Committee member) / Goryll, Michael (Committee member) / Arizona State University (Publisher)
Created2012
Description
Power management plays a very important role in the current electronics industry. Battery powered and handheld applications require novel power management techniques to extend the battery life. Most systems have multiple voltage regulators to provide power sources to the different circuit blocks and/or sub-systems. Some of these voltage regulators are low dropout regulators (LDOs) which typically require output capacitors in the range of 1's to 10's of µF. The necessity of output capacitors occupies valuable board space and can add additional integrated circuit (IC) pin count. A high IC pin count can restrict LDOs for system-on-chip (SoC) solutions. The presented research gives the user an option with regard to the external capacitor; the output capacitor can range from 0 - 1µF for a stable response. In general, the larger the output capacitor, the better the transient response. Because the output capacitor requirement is such a wide range, the LDO presented here is ideal for any application, whether it be for a SoC solution or stand-alone LDO that desires a filtering capacitor for optimal transient performance. The LDO architecture and compensation scheme provide a stable output response from 1mA to 200mA with output capacitors in the range of 0 - 1µF. A 2.5V, 200mA any-cap LDO was fabricated in a proprietary 1.5µm BiCMOS process, consuming 200µA of ground pin current (at 1mA load) with a dropout voltage of 250mV. Experimental results show that the proposed any-cap LDO exceeds transient performance and output capacitor requirements compared to previously published work. The architecture also has excellent line and load regulation and less sensitive to process variation. Therefore, the presented any-cap LDO is ideal for any application with a maximum supply rail of 5V.
ContributorsTopp, Matthew (Author) / Bakkaloglu, Bertan (Thesis advisor) / Thornton, Trevor (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this work, an advanced simulation study of reliability in millimeter-wave (mm-wave) GaN Devices for power amplifier (PA) applications is performed by means of a particle-based full band Cellular Monte Carlo device simulator (CMC). The goal of the study is to obtain a systematic characterization of the performance of GaN devices operating in DC, small signal AC and large-signal radio-frequency (RF) conditions emphasizing on the microscopic properties that correlate to degradation of device performance such as generation of hot carriers, presence of material defects and self-heating effects. First, a review of concepts concerning GaN technology, devices, reliability mechanisms and PA design is presented in chapter 2. Then, in chapter 3 a study of non-idealities of AlGaN/GaN heterojunction diodes is performed, demonstrating that mole fraction variations and the presence of unintentional Schottky contacts are the main limiting factor for high current drive of the devices under study. Chapter 4 consists in a study of hot electron generation in GaN HEMTs, in terms of the accurate simulation of the electron energy distribution function (EDF) obtained under DC and RF operation, taking into account frequency and temperature variations. The calculated EDFs suggest that Class AB PAs operating at low frequency (10 GHz) are more robust to hot carrier effects than when operating under DC or high frequency RF (up to 40 GHz). Also, operation under Class A yields higher EDFs than Class AB indicating lower reliability. This study is followed in chapter 5 by the proposal of a novel π-Shaped gate contact for GaN HEMTs which effectively reduces the hot electron generation while preserving device performance. Finally, in chapter 6 the electro-thermal characterization of GaN-on-Si HEMTs is performed by means of an expanded CMC framework, where charge and heat transport are self-consistently coupled. After the electro-thermal model is validated to experimental data, the assessment of self-heating under lateral scaling is considered.
ContributorsLatorre Rey, Alvaro Daniel (Author) / Saraniti, Marco (Thesis advisor) / Kitchen, Jennifer (Committee member) / Goodnick, Stephen M (Committee member) / Thornton, Trevor (Committee member) / Arizona State University (Publisher)
Created2018
Description
South Korea possesses the only culture to successfully create a transnationality and hybridity formula that is not replicable. So why Korea and why now? The goal of this thesis creative project is to demonstrate the marketing and communications strategies used in the arts and culture industry to drive global awareness and interest in K-Pop. In order to achieve that goal, I created HellotoHallyu.com, a website designed for an audience of Millennials and Generation Z English speakers to increase their awareness of the growth and impact of the Korean Wave in a fun and engaging way. So those who may hear a song by K-Pop idol group BTS on a music awards show in the U.S. can get themselves up-to-speed before diving into the fast-paced world of K-culture gossip sites and forums. Hello to Hallyu delivers consumer-friendly, educational content easily understood by English speakers with no prior knowledge of Korean culture, while still piquing the interest of K-pop connoisseurs. It provides the background necessary for even the most dedicated fans to glean new knowledge of Korea's cultural industry and a new perspective on the content they consume. Hello to Hallyu is based on a combination of secondary and primary research conducted over four semesters beginning Spring 2017 and continuing through Spring 2018. This project is set up as an ever-expanding resource freely available to anyone with internet access. The research required to maintain the site will continue with the Wave. However, the content currently on the site is evergreen, a documentation of the history of the Wave as explained in peer-reviewed articles and by Dr. Ingyu Oh as well as a documentation of my personal experience with Hallyu while in Korea and as a Westerner living in the U.S. The site's goal is to demonstrate the marketing and communications strategies used in the industry to drive global awareness and interest. Through this means, Hello to Hallyu aims to provide fully developed multimedia content intended to increase English speakers' awareness of the growth and impact of the Korean Wave as shown through site visits, content views, and audience engagement.
ContributorsTravis, Lisa Anne (Author) / Hass, Mark (Thesis director) / Shewell, Justin (Committee member) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / School of Film, Dance and Theatre (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This honors thesis outlines a method for teaching argument writing in the secondary classroom, including the elements of an argument based upon the Toulmin method, and diverse ways to help students who are all types of learners become engaged and receive the support they need. It includes all elements of argument, including evidence, warrants, backing, counterargument, claims, theses, the rhetorical triangle and the rhetorical appeals, including definitions and how they fit together in an argumentative essay. The largest portion of the project is dedicated to activities and resources for teachers based upon all of those elements, along with activities for the writing process as a whole. These activities are based upon the student's individual experience as well as various scholarly resources from leading professionals in the curriculum development field for English Language Arts. This is not meant to be an end-all be-all solution for teaching argument writing, but rather one of many resources that teachers can use in their classroom. This 30-page paper, including references, are condensed into an accessible website for teachers to use more easily. Each tab on the website refers to a different element or focus of the argument writing process, with both a definition and introduction as well as one or more activities for teachers to implement into the classroom. The activities are versatile and general for the purpose of teachers being able to include them into whatever curriculum they are currently teaching. The goal is that they can add argument instruction into what they are already either willingly or being required to teach in an easy and logical way. The website is available for any secondary teachers to use as they see fit at www.teachingargumentwriting.weebly.com.
ContributorsBrooks, Jenna Nicole (Author) / Blasingame, James (Thesis director) / Barnett, Juliet (Committee member) / Division of Teacher Preparation (Contributor) / School of Film, Dance and Theatre (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The SolarSPELL is an offline, ruggedized, digital library, created by Dr. Laura Hosman for the U.S. Peace Corps. It has thousands of pieces of educational content that can be accessed through a self-contained Wi-Fi hotspot on the device itself. Currently, there are more than 200 deployed in several Pacific Island nations. After visiting one of these nations, Tonga, in December of 2016, I learned that almost all of the Peace Corps volunteers stationed around the Pacific Islands suffered from a lack of resources due to a variety of reasons. While the SolarSPELL helps to remedy that, the device is lacking classroom activities and resources for creative work and educational drama. Furthermore, for many students in these environments, schools are for learning information and producing high scores on exams, not for learning about creative strengths and identity. After researching curriculum development and the use of drama in an educational setting, I compiled over 50 pieces of content to include on the SolarSPELL involving art, drama, music, movement, and most importantly, imagination. These resources will allow Peace Corps volunteers to explore additional ways to teach English in their schools, while also creating a classroom environment that allows for creative expression. All the content is compiled into one folder as "Teaching Resources", and is then broken down into seven sub- categories. In the first sub-category, Art Projects, there is a collection of several hands-on projects, many of which involve recyclable or readily available materials. These projects will allow for a greater understanding of conservation and "green" living, concepts that are crucial to the stability of these island nations. The next 5 categories are Drama Readings, Music, Movement, and Video, Group Exercises, Creative Writing, and Worksheets. The second sub- category is a collection of beginner-level "Reader's Theater" scripts. The third sub-category involves music and video to engage students in movement activities. The fourth sub-category is a compilation of group games and activities to help students express themselves and learn social skills. The fifth sub-category includes a collection of activities such as fill-in-the-blank story worksheets and journal prompts which will aid in creative thinking and the practice of the English language. The sixth sub-category involves a collection of worksheets that mainly focus on self-reflection and identity. The seventh and final sub-category, Content Guide and Information, works to explain the benefits of using of drama and creative play in the classroom, as well as strategies teachers can implement in order to further engage their students in dramatic learning and play. Overall, these pieces of content are meant to be used as resources for the Peace Corps volunteers in order to provide alternative ways to practice reading, writing, and speaking the English language, a critical part of education in the Pacific Islands.
ContributorsTaylor, Amanda Nicole (Author) / Hosman, Laura (Thesis director) / McAvoy, Mary (Committee member) / School of Film, Dance and Theatre (Contributor) / Division of Teacher Preparation (Contributor) / Barrett, The Honors College (Contributor) / School for the Future of Innovation in Society (Contributor)
Created2017-12
Description
Fringe: Abstract Fringe is a feature length screenplay and a work of original science fiction. The story takes place in the future, on a planet far from Earth but it is told from the human perspective and is meant to draw into question many issues present in society today: prejudice, hatred, multiculturalism, war, and social division. The screenplay seeks to pose an allegorical relationship between the humanity living on the planet, and the enemies they face, and the present day conflict between America and the Middle East or ISIS. The story follows Miles as he is forced to ally with his sworn enemy, the Lue, and learn to fight together to save his world from destruction. Miles begins the film bitter, resentful, and filled with prejudice towards his foes, much like a majority of Americans today. Instead of focussing on that conflict though, my story unites these two bitter enemies and asks them to put aside their violent and hateful pasts to fight a new, more powerful foe together. As the events unfold my characters learn that their enemies can be just like them and that they have something valuable to offer their world. My screenplay is about finding commonality with the enemy, on both sides of a conflict. By the end of my tale, Miles learns that there is good to be found in the world, even in his sworn enemies, if he looks close enough. It may seem like an archetypal plot on the surface but I worked hard to create a world that has not been seen in film before, an original science fiction universe that can bring these issues into the light and entertain an audience while doing so. I feel that my screenplay does just that, offering entertainment with and edge of social commentary, and stays true to the science fiction form.
ContributorsTrcic, Colton Walker (Author) / Maday, Gregory (Thesis director) / Bernstein, Gregory (Committee member) / WPC Graduate Programs (Contributor) / W. P. Carey School of Business (Contributor) / School of Film, Dance and Theatre (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05