Index Catalog // ScholarsArchive@OSU

Determination of magnetoelastic parameters in magnetic thin films from FMR spectra

Creator:: Masood, Khalid I.
Abstract:: The ferromagnetic resonance (FMR) phenomenon serves as a sensitive probe of the effective internal fields in a magnetic material. FMR spectroscopy has consequently become a well-established technique, extensively employed in assessing material properties such as magnetic anisotropy, Landé g-factor, damping parameter, and the magnetoelastic constants of magnetic materials. Determining these...
Resource Type:: Dissertation

Modeling of Wave Energy Converter via Instantaneous Frequency

Creator:: Kim, Inyong
Abstract:: A multidisciplinary perspective is necessitated for the analysis of wave energy conversion systems, spanning hydrodynamics, mechanics, electric power, and control systems. The complexity inherent in these scientific domains poses challenges for unified analysis. This paper addresses these challenges by connecting various domains through the application of circuit theory, characterizing the...
Resource Type:: Masters Thesis

Secure Data Analytics under Data Integrity Attacks

Creator:: De Silva, Shashini A.
Abstract:: There has been tremendous growth in using data analytic and machine learning algorithms to make critical decisions, such as in the national power grid, healthcare operations, and autonomous vehicles. Employing data analytic for decision-making allows cyber attackers to manipulate the decisions of these algorithms through data falsification. Hence, the trustworthiness...
Resource Type:: Dissertation

Sensor Interface Circuit Design towards CMOS Scaling

Creator:: Liu, Jialin
Abstract:: Sensor system plays an important role in connecting everything including human body to the electrical information systems that we have built and that we are going to build, to make the world more intelligent and efficient. One of the key propulsive forces behind these emerging techniques is CMOS scaling that...
Resource Type:: Dissertation

Action Selection for Heterologous Control of a Continuous-Output Myoelectric Prosthesis

Creator:: Sylwester, Sean T.
Abstract:: Signiﬁcance: Movement intent decoding algorithms can interpret human bioelectrical signals to control prosthetic limbs with many degrees of freedom (DOFs). This work involves decoding volitional movement intent from surface electromyogram (sEMG) signals to control prosthetic arms. To train these algorithms, patients ﬂex their muscles to “follow” a movement prompt, and...
Resource Type:: Masters Thesis

Identifiability-Aware Joint Sparse Error Correction For Robust State Estimation

Creator:: Kibria, Sharmin
Abstract:: We study joint nonlinear state estimation with multi-period measurement vectors that are potentially corrupted by sparse gross errors. The identifiability-aware approach is proposed to leverage common characteristics of fundamentally identifiable gross errors to enhance error correction performance. First, we derive a necessary rank condition that the sparsity pattern of any...
Resource Type:: Dissertation

Hybrid AOA and TDOA Solution for Transmitter Positioning

Creator:: Ahmed, Sarah A.
Abstract:: Accurate positioning has become an active research area in recent years. It has a wide range of applications in many fields such as navigation, asset tracking, health care, proximity marketing/location-based advertising, and sport analytics. Transmitter positioning via radio frequency (RF) signals is the most widely encountered scenario, and it uses...
Resource Type:: Masters Thesis

Power Network Parameter Correction via Sparse Unsupervised Regression

Creator:: Senaratne, Galpottage Dilan S.
Abstract:: Accurate information of power network parameters is essential for performing various power system monitoring and control tasks including state estimation, economic dispatch, and contingency analysis. In this paper, we present a novel approach of power network parameter correction wherein we exploit the sparse nature of parameter errors. Parameter error correction...
Resource Type:: Masters Thesis

Crowdsourcing via Pairwise Co-occurrences: Identifiability and Algorithms

Creator:: Ibrahim, Shahana
Abstract:: Crowdsourcing is a popular paradigm to address the high demands for labeled data in big data deluge. It aims to produce accurate labels by eﬀectively integrating noisy, non-expert labeling from crowdsourced workers (annotators). The machine learning community has been studying eﬀective crowdsourcing methods for many years, and many models and...
Resource Type:: Masters Thesis

Design Considerations and Circuit Techniques for Robust Ring-Amplifiers

Creator:: Venkatachala, Praveen Kumar
Abstract:: Ring amplifiers (ringamps) have shown excellent power efficiency in the latest state-of-the-art analog to digital converters (ADCs). This thesis describes circuit techniques to ensure robust operation of ringamps using standard analog techniques and proportional-integral-derivative(PID) controller analogy. Large-signal and small-signal analysis of a ringamp are performed using simple RC settling and...
Resource Type:: Dissertation

Lamb Wave Mode Decomposition and Its Applications in Structural Health Monitoring

Creator:: Zoubi, Ahmad Bassil
Abstract:: Structural health monitoring (SHM) systems perform automated non-destructive damage detection and characterization for a variety of large structures including civil structures such as bridges and aerospace structures such as aircrafts and space vehicles. The goals of SHM include preventing catastrophic structural failures, increasing reliability, reducing maintenance costs, and increasing the...
Resource Type:: Dissertation

Coupled Compressive Sensing : Sequential Reinforcement Approach

Creator:: De Silva, Shashini A.
Abstract:: We consider multiple Compressive Sensing (CS) problems wherein the supports of signal vectors of CS problems are restricted to satisfy a collection of joint logical constraints, which we refer to as coupling constraints. We consider a case where the coupling constraints are encoded in a graph and present a sequential...
Resource Type:: Masters Thesis

Sliding Mode Control of Oscillating Water Column Wave Energy Converters

Creator:: Brown, Danielle R.
Abstract:: This thesis concerns the development of a direct torque control strategy using a sliding mode control approach to optimize the power output of an oscillating water column (OWC) wave energy converter (WEC). The OWC WEC is a device that has a submerged vertical tail tube open at both ends, which...
Resource Type:: Masters Thesis

A Micro Scale Magnetic Particle Imaging System

Creator:: Lenox, Philip A.
Abstract:: Magnetic particle imaging (MPI) is a biomedical imaging technique which detects the presence of magnetic nanoparticles which have been introduced into the specimen prior to imaging. MPI has shown promise for real-time imaging with spatial resolution comparable to magnetic resonance imaging (MRI). MPI research has focused predominantly on the development...
Resource Type:: Masters Thesis

Position estimation in indoor localization with trilateration

Creator:: Su, Zhenqiang
Abstract:: Triangulateration uses geometric distance to estimate the location of user by employing techniques like received signal strength (RSS), time-of-arrival (TOA), time-difference-of-arrival (TDOA) and image processing. Radio frequency (RF) signal positioning using TOA or TDOA techniques generally requires timing synchronization of the anchors and/or the anchors and targets. If the desired...
Resource Type:: Dissertation

Simultaneous segmentation and classification of bird song using CNN

Creator:: Narasimhan, Revathy
Abstract:: In bioacoustics, automatic animal voice detection and recognition from audio recordings is an emerging topic for animal preservation. Our research focuses on bird bioacoustics, where the goal is to segment bird syllables from the recording and predict the bird species for the syllables. Traditional methods for this task addresses the...
Resource Type:: Masters Thesis

Power Efficient Architectures for High Accuracy Analog-to-Digital Converters

Creator:: Zhang, Yi
Abstract:: Incremental ADCs (IADCs) have found wide applications in sensor interface circuitry since, compared to ∆Σ ADCs, they provide low-latency high-accuracy conversion and easy multiplexing among multiple channels. On the other hand, continuous-time ∆Σ ADCs (CTDSM) have been receiving more and more attention as a power-efficient solution in targeting medium to...
Resource Type:: Dissertation

Modeling, Fabrication, and Characterization of Magnetic Thin Films for Integrated Inductor and MRAM Applications

Creator:: Buford, Benjamin
Abstract:: Magnetic thin films have potential to improve devices such as on-chip inductors, and enable new technologies such as magnetic random access memory (MRAM). The use of magnetic cores in on-chip inductors is typically limited to applications well under 1 GHz. At higher frequencies, the performance of the magnetic core is...
Resource Type:: Dissertation

Ultra-Wideband Relay Communication Systems

Creator:: Abbasi, Arash
Abstract:: Impulse-radio ultra-wide-band (IR-UWB) signaling is a promising technique for high-speed, short-range relay communications networks. Depending on how the relay node retransmits the signal, there are two main relay schemes: conventional one-directional (one-way) relay model, and bi-directional (two-way) relay model. In bi-directional relay communications, wireless network coding (WNC), also called physical-layer...
Resource Type:: Dissertation

Linearity enhancement techniques for data converters

Creator:: Cao, Jinzhou
Abstract:: Data converters are essential interface circuits between the analog world that people live in and the digital processors that people live with. Linearity, which often is a tradeoff against other performance criteria, is one of the major performance demands from applications for both analog-to-digital converts (ADC) and digital-to-analog converters (DAC)....
Resource Type:: Dissertation

Position estimation in indoor localization system

Creator:: Qiao, Tianzhu
Abstract:: Indoor positioning systems can be used for many applications such as indoor navigation,emergence response, asset monitoring, and shopper assistance. Due to the weak received signal and multipath reflection, the global positioning system (GPS) generally does not work in indoor environments. There are a variety of radio frequency (RF) signals and...
Resource Type:: Dissertation

Wideband and high accuracy delta sigma modulation data converter

Creator:: Jung, Youngho
Abstract:: Nowadays, needs for wideband and high accuracy analog-to-digital converter are increasing rapidly in manifold applications such as wireless communication, digital video and other consumer electronics. Besides, low power consumption is required to have longer battery life in portable systems. CMOS technology scaling and innovative modulator topology make the implementation much...
Resource Type:: Dissertation

Parameter estimation of Gaussian hierarchical model using Gibbs sampling

Creator:: Mbuthia, Juliana
Abstract:: Gibbs sampling method is an important tool used in parameter estimation for many probabilistic models. Specifically, for many scenarios, it is difficult to generate high-dimensional data samples from its joint distribution. The Gibbs sampling provides a way to draw high-dimensional data via the conditional distributions which are typically easier to...
Resource Type:: Masters Thesis

Compensation method of the excess loop delay in continuous-time delta-sigma ADCs based on model matching approach

Creator:: Guo, Jia
Abstract:: Continues-Time (CT) Delta-Sigma (ΔΣ) Analog-to-Digital Converters (ADCs) have one important constrain, namely the excess loop delay. Most previous excess lop delay compensation methods need to know the exact value of the excess loop delay in advance. However, the value of the excess loop delay is a uniformly distribution random variable....
Resource Type:: Masters Thesis

A remotely operated, autonomous wave energy converter system

Creator:: Lewis, Timothy M.
Abstract:: The potential for electric energy generation from ocean waves is substantial and much research is being conducted on the conversion process as a renewable, grid-connected, power source. Some of the same attributes that make wave energy harvesting attractive as a grid-connected source also make it attractive as a remote, or...
Resource Type:: Dissertation

Micropower incremental analog-to-digital converters

Creator:: Chen, Chia-Hung
Abstract:: Incremental ADCs (IADCs) have many advantages for low-frequency high-accuracy data conversion—they are easy to multiplex between channels, need simpler digital decimation filter, and allow extended counting with a Nyquist-rate ADC. A single-loop incremental ADC was designed and fabricated in 90 nm for a biosensor interface circuit. It incorporates one integrator,...
Resource Type:: Dissertation

Design techniques for low power high speed successive approximation analog-to-digital converters

Creator:: Lin, Jiaming
Abstract:: This dissertation presents two high-speed pipeline successive approximation analog-to-digital converters (SAR ADCs). Capacitive DACs and resistive DACs are utilized in these two pipeline SAR ADCs, respectively. The pipeline SAR ADC with capacitive DACs can save 50% switching power compared with other time-interleaved SAR ADCs since the total capacitance of the...
Resource Type:: Dissertation

Adiabatic Markov Decision Process : convergence of value iteration algorithm

Creator:: Duong, Thai
Abstract:: Markov Decision Process (MDP) is a well-known framework for devising the optimal decision making strategies under uncertainty. Typically, the decision maker assumes a stationary environment which is characterized by a time-invariant transition probability matrix. However, in many real-world scenarios, this assumption is not justified, thus the optimal strategy might not...
Resource Type:: Masters Thesis

Fast queuing policies via convex relaxation

Creator:: Nguyen-Huu, Duong
Abstract:: Traditionally, networking protocol designs have placed much emphasis on point-to-point reliability and efficiency. With the recent rise of mobile and multimedia applications, other considerations such as power consumption and/or Quality of Service (QoS) are becoming increasingly important factors in designing network protocols. As such, we present a new flexible framework...
Resource Type:: Masters Thesis

Testing of wave energy converters using the Ocean Sentinel Instrumentation Buoy

Creator:: Lettenmaier, Terrance
Abstract:: Ocean testing of Wave Energy Converter (WEC) prototypes is necessary to facilitate commercial WEC development. The Ocean Sentinel Instrumentation Buoy, completed in August 2012, provides a stand-alone load for WEC prototypes during ocean testing. The first part of this work was to develop the power conversion and data acquisition equipment...
Resource Type:: Dissertation

Development of a grid-scale energy storage solution via demand response using model predictive control of multiple residential water heaters

Creator:: Halamay, Douglas A.
Abstract:: As the growth of renewable energy sources, such as wind, solar, and ocean wave, increases, their impact on the electrical grid has been rapidly escalating. Although renewable resources have been able to offset some traditional generation, they have also brought a need for increasing reserve capacity due to their non-dispatchable,...
Resource Type:: Dissertation

Modeling and analysis of spur structure of digital-to-time conversion based frequency synthesizers

Creator:: Talwalkar, Sumit A.
Abstract:: Frequency synthesizers are critical components of all communication systems. This thesis considers the issue of undesirable frequency spurs of a relatively recent type of frequency synthesis architecture called digital-to-time conversion (DTC). The DTC-based frequency synthesis architecture has important performance benefits over older frequency synthesizers, such as fast frequency switching, large...
Resource Type:: Dissertation

Linearizing techniques for voltage controlled oscillator based analog to digital converters

Creator:: Rao, Sachin B.
Abstract:: Voltage controlled oscillator (VCO) based ADC is an important class of time-domain ADC that has gained widespread acceptance due to their several desirable properties. VCO-based ADCs behave like an open-loop continuous time ΔΣ modulator and achieve excellent resolution by first order noise shaping the quantization error. However, the SNDR of...
Resource Type:: Dissertation

Efficient detection and scheduling for MIMO-OFDM systems

Creator:: Liu, Wei
Abstract:: Multiple-input multiple-output (MIMO) antennas can be exploited to provide high data rate using a limited bandwidth through multiplexing gain. MIMO combined with orthogonal frequency division multiplexing (OFDM) could potentially provide high data rate and high spectral efficiency in frequency-selective fading channels. MIMO-OFDM technology has been widely employed in modern communication...
Resource Type:: Dissertation

Ultra-wideband indoor localization systems

Creator:: Ye, Ruiqing
Abstract:: Indoor localization systems have a variety of applications such as tracking of assets, indoor robot navigation, and monitoring of people (e.g. patients) in hospitals or at home. Global positioning system (GPS) offers location accuracy of several meters and is mainly used for outdoor location-based applications as its accuracy degrades significantly...
Resource Type:: Dissertation

High efficiency wideband low-power delta-sigma modulators

Creator:: Lee, Sang Hyeon
Abstract:: Delta-sigma analog-to-digital converters traditionally have been used for low speed, high resolution applications such as measurements, sensors, voice and audio systems. Through continued device scaling in CMOS technology and architectural and circuit level design innovations, they have even become popular for wideband, high dynamic range applications such as wired and...
Resource Type:: Dissertation

Simulator for optimizing performance and power of embedded multicore processors

Creator:: Goska, Benjamin J.
Abstract:: This work presents improvements to a multi-core performance/power simulator. The improvements which include updated power models, voltage scaling aware models, and an application specific benchmark, are done to increase the accuracy of power models under voltage and frequency scaling. Improvements to the simulator enable more accurate design space exploration for...
Resource Type:: Masters Thesis

Optimal communications system design for array-based electric generation

Creator:: Orozco, Ricardo
Abstract:: The world's demand for energy is an ongoing challenge, which has yet to be overcome. The efforts to find clean energy alternatives to fossil fuels have been hampered by the lack of investment in technology and research. Among these clean energy alternatives are ocean waves and wind. Wind power is...
Resource Type:: Masters Thesis

An adiabatic approach to analysis of time inhomogeneous Markov chains : a queueing policy application

Creator:: Zacharias, Leena
Abstract:: In this thesis, convergence of time inhomogeneous Markov chains is studied using an adiabatic approach. The adiabatic framework considers slowly changing systems and the adiabatic time quantifies the time required for the change such that the final state of the system is close to some equilibrium state. This approach is...
Resource Type:: Masters Thesis

Computationally efficient block diagonalization for downlink multiuser MIMO-OFDM systems

Creator:: El Amrani, Samia
Abstract:: One of the key challenges in downlink multiuser multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is the mitigation of the multi-access interference when different users share the same subcarriers. In this work, the block diagonalization (BD) algorithm for inter-user interference pre-cancelation is extended to MIMO-OFDM systems. However, in...
Resource Type:: Masters Thesis

Understanding the ultra-wideband channel within a computer chassis

Creator:: Redfield, Stephen J.
Abstract:: Recent developments in computing technology have generated a demand for more streamlined and effective test systems. By replacing traditional in-chassis wired interconnects with a broadcast wireless system, fault detection and error susceptibility will drastically improve, input/output capabilities will expand, and routing complexity will decrease. Ultra-wideband impulse radio's (UWB-IR) characteristic multipath-immunity...
Resource Type:: Masters Thesis

Feedback in multiple antenna wireless communication systems

Creator:: Xu, Tao
Abstract:: Multiple-input multiple-output wireless systems promise significant capacity gain and/or diversity gain over single antenna systems. If channel state information (CSI) is available at both the transmitter and the receiver, the performance can be further improved. In this thesis, first, we study binary index feedback problem in beamforming systems when the...
Resource Type:: Dissertation

A comparative study between sinusoidal and squarewave clocking for alleviating the jitter limitation in multi-gigaHertz ADCs

Creator:: Kesharwani, Divya
Abstract:: Various applications like wireless UWB communication, fast data acquisition systems and digital storage oscilloscopes needs ADCs with instantaneous input signal bandwidth from 0.1-40 GigaHertz range with 6-10 bits of resolution -- a challenging task and an impressive goal to achieve. Flash ADCs have been conventionally employed to achieve these goals...
Resource Type:: Masters Thesis

A force control algorithm for a wave energy linear test bed

Creator:: Henshaw, Nathan R.
Abstract:: Researchers at Oregon State University, focusing on the development of ocean wave energy converters, have designed and installed a unique linear test bed to aid in the characterization of these converters. Under the original control scheme, the linear test bed follows a position profile and is limited in its ability...
Resource Type:: Masters Thesis

Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic

Creator:: Yousefi, Siavash
Abstract:: A two-channel data acquisition system for simultaneous detection and discrimination of beta particles and gamma rays has been developed. Each channel measures and analyzes the input pulses resulting from the absorption of radiation in the layers of the detector. The detector is a triple-layer phoswich (phosphor sandwich) scintillation detector followed...
Resource Type:: Masters Thesis

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