Portable, high power efficiency communication devices is a growing market in the semiconductor industry. Analog-to-digital converters (ADC) are key interface that are used to digitize the sensed information. Recently, digital techniques have been proposed to improve analog building block power efficiency in sub-micron technologies. This research focuses on mixed signal...
Ocean waves provide a promising source of renewable energy for the North American electric grid. However, ideal control of wave energy converters (WECs) requires perfect forecasting of future wave conditions, and waves can be unpredictable. This paper presents a comparison of three different prediction methods and analyzes their performance in...
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...
Heatmap regression has became one of the mainstream approaches to localize facial landmarks. As Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN) are becoming popular in solving computer vision tasks, extensive research has been done on these architectures. However, the loss function for heatmap regression is rarely studied. In...
To users, mobile touchscreen devices have appealing characteristics; among these characteristics is intuitiveness, which leads to mobile devices being used almost everywhere by almost everyone to accomplish almost anything. This statement, to some degree, holds for children too. Despite touchscreen devices’ intuitiveness and popularity, we don’t know much about how...
Question answering forums like Reddit have been quite effective in improving social interaction and disseminating useful information. Community members ask a variety of questions related to a subject which are answered by other community members. The answers are given ratings by other members. In this thesis we study the problem...
This dissertation focuses on indoor free-space optical communications systems for use in short range wireless networks. We propose that current radio frequency wireless links be augmented or replaced with optical frequency links due to overcrowding in the radio frequency spectrum. Optical frequencies contain hundreds of terahertz of unregulated bandwidth and...
Due to the continued evolution of 5G standards, the need for higher rates of data, lower latency network access, and implementations that are more energy efficient have become clear. To enable wireless communications at rates over tens of Gbps, the wide bandwidth of mmWave spectrum can be exploited. Beamforming (or...
The energy barrier heights between two recently reported Ta-based amorphous metals (TaWSi and TaNiSi), TaN, and atomic layer deposited Al2O3 and HfO2 insulators are measured in metal/insulator/metal (MIM) structures with Au top electrodes using internal photoemission (IPE) spectroscopy. For Al2O3, the Ta-based metal barrier heights, phi(Bn), increase with increasing metal...
The Pacific Northwest is part of the "Ring of Fire," which is well-known for heavy seismic activity. Numerous active faults in the area have encouraged electric grid managers in the region to more deeply contemplate and proactively intervene to support grid resilience. This research introduces Monte Carlo (MC) based power...
The CMOS two-stage Operational Transconductance Amplifier (OTA) has been a key enabler for mixed-signal IC design for nearly four decades . This research focuses on a modified two-stage CMOS OTA that features load-pole cancellation (LPC); i.e., the resulting architecture is essentially a two-stage CMOS OTA with no load capacitance. The...
Millimeter-wave (mm-wave) technology promises high speed, high system capacity and low latency interconnects with reduced cost. Applications like high data-rate wireless links, next generation automotive sensors and security body scanners highly depend on mm-wave technology innovations. As operating frequency moves to higher mm-wave bands, shrinking antenna dimensions enable co-integration of...
Low-power millimeter-wave (mm-wave) transceivers are of interest for achieving energy-efficient high data rate short-reach wireless and guided-wave links.
Spatial modulation or space-shift keying (SSK) can provide energy efficiency improvements by using antenna-switching or transmission direction switching for data modulation. Such links are particularly attractive at millimeter-wave frequencies due to small...
In any biomedical signal acquisition system, a front-end amplifier is needed to amplify low amplitude bio-signals while filtering out any unwanted low-frequency artifacts. The design of low frequency poles within the sub-Hz range implies very large time-constants which goes against system integrability. In recent years, the pseudo resistor has been...
As the number of wireless devices, the demand for high data rates, and the need for always-on connectivity are growing and becoming more stringent with the evolvement and emergence of 5G systems, network engineers and researchers are being faced with new unique challenges that need to be addressed. Among many...
Efficient time-series analysis can impact multiple application domains such as motif discovery in gene analysis or music data, extracting spectro-temporal patterns in acoustic scene analysis, or annotating and classifying electrical bio-signals (such as ECG, EEG, and EMG) for medical applications.
Time-series analysis involves a variety of tasks.
To predict future...
With the rapid growth of worldwide internet traffic in data centers and clouds, silicon photonics has been utilized to provide enormous data bandwidth and outstanding energy efficiency over electronics. Computing servers and storage servers that are connected by communication links are relying more on optical rather than electrical means mainly...
Research in geoscience often requires transmission of significant amounts of data from remote locations. The emergence of microcontrollers and open-source sensors are allowing connectivity to affordable, distributed in-situ monitoring. This report describes the OPEnS Hub, a modular data hub orders of magnitude cheaper than commercial dataloggers when scaled to multiple...
In Earth science, we must often collect data from sensors installed in remote locations. Retrieving these data and storing them can be challenging. Present options include proprietary commercial dataloggers, communication devices, and protocols with rigid software and data structures that may require ongoing expenses. While there are open-source solutions that...
Deep learning and neural network has been widely used in research, deep learning has empowered many tasks such as point clouds segmentation and shape recognition. One of the main advantages of deep interaction point cloud segmentation is that it allows the feature extraction can be learned through neural network based...
In this research, we address the problem of learning a single causal network structure from multiple dataset generated from different experiments. The experiments can be observational or interventional. We assume that each dataset is generated by an unknown causal network altered under different experimental conditions (interventions, manipulation or perturbation). As...
As the power system grows larger and more complex, real-time monitoring and control become very significant in order to achieve reliable operation of the power system. Before any security assessment can be made or control actions are taken, the reliable estimate of the existing state of the system must be...
In recent years, SAR ADCs have been shown to acheive faster conversion times and improved power efficiencies due to their simple building blocks that are digital in nature and scale favorably with technology. High resolution ADCs with stringent noise requirement has led to the adoption of hybrid ADC architectures such...
Although the need for gender-inclusivity in software itself is gaining attention among both SE researchers and SE practitioners, and methods have been published to help, little has been reported on how to make such methods work in real-world settings. For example, how do busy software practitioners use such methods in...
This report presents an efficient method for semi-supervised video object segmentation – the problem of identifying foreground pixels occupied by a target object. The target is specified by the ground-truth mask in the first video frame. While the state of the art achieves a segmentation accuracy greater than 80%, it...
The increased demand for building materials that are friendly to the environment, along with the latest advances in wood science and technology, which exploit the fiber orientation of wood, resulted in composite wood materials known as mass-timber products. To understand the effects the wood fiber orientation has on the dynamic...
Conventional Delta-Sigma analog-to-digital converters (ADCs) utilize operational transconductance amplifiers (OTAs) in their loop filter implementation followed by multi-bit voltage domain quantizers. As CMOS integrated circuit technology scales to smaller geometries, the minimum transistor length and the intrinsic gain of the transistors decrease. Moreover, with process scaling the voltage headroom decreases...
While electrification is currently one of the largest trends in the automotive world, other related industries are also evaluating electrification opportunities as a means to reduce environmental impact, emissions, and noise pollution. One such sector is the aviation industry. While it is generally accepted that all-electric aircraft are not a...
Load flow studies are one of the most essential engineering applications for grid operators because they provide a clear picture of the operating conditions of the power system. Traditionally, the load flow problem is assumed to be deterministic; that is, the system variables contain no randomness. Unfortunately, this assumption is...
There are nearly two million limb amputees living in the United States of America. Loss of limbs results in profound changes in one's life. However, the underlying neural circuitry and much of the ability to sense and control movements of their missing limb is retained even after limb loss. This...
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...
Anomaly detection has been used in variety of applications in practice, including cyber-security, fraud detection and detecting faults in safety critical systems, etc. Anomaly detectors produce a ranked list of statistical anomalies, which are typically examined by human analysts in order to extract the actual anomalies of interest. Unfortunately, most...
Learning novel concepts from relational databases is an important problem with applications in several disciplines, such as data management, natural language processing, and bioinformatics. For a learning algorithm to be effective, the input data should be clean and in some desired representation. However, real-world data is usually heterogeneous – the...
We consider the problem of computing the cannonical polyadic decomposition (CPD) for large-scale dense tensors. This work is a combination of alternating least squares and fiber sampling. Data sparsity can be leveraged to handle large tensor CPD, but this route is not feasible for dense data. Inspired by stochastic optimization's...
Spreadsheets are a pervasive technology throughout personal and industrial use. Often times, the user is not the author, contributing to a lack of understanding of the purpose and functionality of a spreadsheet. Furthermore, the lack of understanding is a major reason for mistakes in the use and maintenance of spreadsheets....
Modern communication systems often have the ability to transmit signals on multiple communication mediums (e.g., RF, visible light) or interfaces (e.g., MAC layer protocols) at the same time. While each channel has different characteristics, a centralized controller with channel condition information will be able to schedule the resource allocated to...
Traditional approaches to streaming H.264 video over a network typically rely on a single method of transport (i.e., reliable or unreliable) and/or use static values for parameters that can have a significant negative impact on the perceptual quality of the received video. This dissertation presents a dynamic method for wireless...
This thesis deals with target localization using multiple-input multiple-output (MIMO) radars. In the field of communications, navigation, radar, and sensing networks, one of the common and most sophisticated problems is target localization. We develop a target localization scheme in distributed MIMO radar systems using bistatic range measurements. The localization approach...
Wearable sensors with an inertial measurement unit (IMU) are popular for indoor positioning and activity pattern detection. The IMUs can be connected to a wireless transmission module, allowing users to monitor and process motion-related parameters remotely. Because of the complexity and uncertainty of signals in indoor environments, a radio frequency...
Traditional bus-based interconnects are simple and easy to implement, but the scalability is greatly limited. While router-based networks-on-chip (NoCs) offer superior scalability, they also incur significant power and area overhead due to complex router structures. In this thesis, a new class of on-chip networks, referred to as Routerless (RL) NoCs,...
The Jetson Artificial Intelligence Tool chain (JAI-TC) is a set of packages, APIs and libraries for Artificial Intelligence applications to be deployed on the NVidia SOC, Jetson TX2. JAI-TC automates the installation of these items allowing for a wider set of users to leverage these technologies. Prior to this, the...
This work demonstrates correlation of microwave signals encoded with 16-bit codes using the parametric interaction of spin waves. Signal processing correlators are devices that compare two signals, such as a reference code and a received code, where the output indicates the similarity between the signals. Correlators are used in communication...
Automatic music transcription (AMT) is the task, given an acoustic representation of music, to recover a symbolic notation of the written notes expressed by the sound. Transcribing music with multiple notes sounding simultaneously is difficult for both humans and machines. Much existing work on AMT has focused on suitable acoustic...
One goal of using robots in introductory computer science (CS) courses is to improve motivation among learners. In this study, we investigate the effectiveness of using the Cozmo and Lego Mindstorm robots to improve students’ motivation in a CS orientation course, and we describe our experience using these robots in...
Narratives are central to communication and the human experience. For a computer system to understand a narrative, it must be able to identify the key facts or plot elements that describe what happened or how the world has changed. These element are called events;establishing a document’s events and the relationships...
The advent of deep learning models leads to a substantial improvement in a wide range of NLP tasks, achieving state-of-art performances without any hand-crafted features. However, training deep models requires a massive amount of labeled data. Labeling new data as a new task or domain emerges consumes time and efforts...
An innovative silver nano-dimple arrays (Ag DAs)-integrated microfluidic device was developed to achieve highly sensitive fluorescence-based nucleic acid detection. The Ag DAs were utilized to produce surface plasmon resonance (SPR) for strong fluorescence enhancement. We systematically investigated the plasmon-enhanced fluorescence by controlling the nanostructure dimension of the Ag DA substrate....
This thesis studies the problem of structured prediction (SP), where the agent needs to predict a structured output for a given structured input (e.g., Part-of-Speech tagging sequence for an input sentence). Many important applications including machine translation in natural language processing (NLP) and image interpretation in computer vision can be...
Scientists and engineers have to analyze and query multiple large databases. Analysis over databases created by phasor measurement units can provide insight into the health of the grid, thereby improving control over operations. Realizing this data-driven control, however, requires validating, processing and storing massive amounts of PMU data efficiently, which...
This research focuses on receiver architectures which enable better spectral eciency
by handling blockers in the same spectral range as the signal. The presence of
such blockers, without the use of blocker cancelling/ltering techniques leads to gain
compression and hence, consequent performance degradation of receivers leading to
reduced spectrum...