There is a growing interest in bringing online and streaming content to the television. Gaming platforms such as the PS3, Xbox 360 and Wii are at the center of this digital convergence; platforms for accessing new media services. This presents a number of interface challenges, as controllers designed for gaming...
Forward Error Correction and retransmission are two approaches used to reliably broadcast data in a network with poor quality of service. Taking some assumptions, it has been suggested that a retransmission based reliable broadcasting scheme using network coding should in theory provide an increase in bandwidth efficiency by combining packets...
With the current security climate throughout the Internet, a large emphasis is being placed on protecting software systems from attack by a malicious entity. Most successful attacks against software are the result of lazy or misinformed developers and are easily prevented given the correct preparation and instruction. This document provides...
This work presents an inductor less switched capacitor based energy harvester, which can simultaneously harvest from 2 energy sources (Solar + Piezo). The proposed harvester employs 2D maximum power point tracking algorithm, by changing the conversion ratios of the charge pumps for piezo and solar sources, and 1D voltage regulation...
Merge conflicts have long plagued software development. With larger and more dispersed teams comes greater risk of developers working on the same code at the same time. While merge conflicts are known to be painful, their exact impact on software is still largely unknown. Are merge conflicts an isolated problem,...
This paper presents an overview of cogeneration, also known as combined heat and power (CHP). The technology of cogeneration is described and the three primary cogeneration processes are discussed. The transition between parallel operation with the utility and stand-alone operation is discussed. The tradeoff between a synchronous and an induction...
An ultra low power crystal oscillator that provides a frequency reference for battery
powered timekeeping applications is presented. An amplitude control circuit is employed to ensure that minimum current is consumed. A subthreshold voltage regulator provides a supply voltage for the oscillator with minimum current consumption. The oscillator and regulator...
A fully integrated CMOS GPS receiver RF front end optimized for low power operation is presented. The system operates with a supply voltage down to 250 mV. A prototype has been fabricated in a 0.13μm CMOS process and includes a low voltage LNA, quadrature oscillators, and quadrature mixers. It exhibits...
This dissertation focuses on the analysis, design, and application of inductor-capacitor (LC) oscillators for wireless sensor networks (WSNs).
First an analysis and design optimization approach for enhanced swing, low power CMOS LC oscillators is presented. A phasor based analysis is used for determining the amplitude and phase noise of these...
High speed serial links are critical components for addressing the growing demand for I/O bandwidth in next-generation computing applications, such as many-core systems, backplane and optical data communications. Due to continued process scaling and circuit innovations, today's CMOS serial link transceivers can achieve tens of Gb/s per pin. However, most...
The release of the IEEE802.15.6 standard has led to increased interest in low-power technologies for wireless body-area-networks (WBANs). The power dissipation, supply voltage, and die area are some of the most important criteria for successful WBAN implementations. Digital-intensive RX architectures can potentially result in sub-1V operation with significant reductions in...
The electrical behavior of on-chip interconnects has become a dominant factor in silicon-based high speed, RF, and mixed-signal integrated circuits. In particular, the frequency-dependent loss mechanisms in heavily-doped silicon substrates can have a large influence on the transmission characteristics of on-chip interconnects. To optimize the performance of the integrated circuit,...
Passive components, including spiral inductors and transformers, fabricated on silicon-based substrates are placing an increasing demand on radio-frequency integrated circuit (RFIC) design. Performance of the RFIC suffers from several non-ideal effects that must be taken into account in order to create a successful design. In particular, monolithic transformers can be...
A novel method for modeling bends in coplanar waveguides (CPWs) is described. The CPW can be viewed as a pair of parallel coupled quasi-slot lines. Bends in the CPW are modeled as a non-uniform coupled line system in terms of their even- and odd- mode characteristics. This modeling approach is...
A new comprehensive wide-band compact modeling methodology for single-ended spiral inductors and differential spiral inductors is presented. The new modeling methodology creates an equivalent circuit model consisting of frequency-independent circuit elements for use in circuit simulators. A fast automated extraction procedure is developed for determining the circuit element values from...
This thesis examines substrate noise coupling for NMOS transistors in heavily doped substrates. The study begins with the analysis of an NMOS transistor switching noise in a digital inverter at the device level. A resistive substrate network for the NMOS transistor is proposed and verified. Coupling between N+- P+ contacts...
Modern wind energy is the technology of choice with a short payback period for increasing renewable energy portfolios. Bonneville Power Administration (BPA), a United States power authority in the Pacific Northwest expects to increase their wind energy capacity from 2,000 megawatts to 6,000 megawatts within the next five years. Currently...
To protect user’s privacy and system’s integrity, mobile platforms use permission models to control accesses to protected resources such as GPS location, Contacts, etc. The previous major version of Android used a static permission model, which compromised the security and privacy of apps. Android 6 overhauled its permission model to...
A fundamental problem in computer vision is to partition an image into meaningful segments. While image segmentation is required by many applications, the thesis focuses on segmentation of computed tomography (CT) images for analysis and quality control of composite materials. The key research contribution of this thesis is a novel...
As the future electrical power systems tend towards smarter and greener technology, thedeployment of self-sufficient networks, or microgrids, becomes more likely. Microgridsmay operate on their own or synchronized with the main grid, thus control methodsneed to take into account islanding and reconnecting said networks. Isolation of subnetworks may be necessary...
"Each year, the grant support varying numbers of teachers to investigate spreadsheets with the intent of integrating teaching mathematics/science with spreadsheets. These teachers were taught to focus on teaching about key concepts of spreadsheet design while they also taught with the spreadsheets as tools for learning mathematics/science. As part of...
Causal inference is an important analytical tool to bridge the gap between prediction and decision-making. However, learning a causal network solely from data is a challenging task. In this work, various techniques have been explored for a better and improved causal network learning from data. Firstly, the problem of learning...
This M.S thesis presents an interactive software tool that I have developed in the course of the past two years. This interactive tool is called AISO. AISO is aimed at interactive image segmentation and annotation tool designed to allow users to segment an image – such as those produced with...
Advances in sensor technology are greatly expanding the range of quantities that can be measured while simultaneously reducing the cost. However, deployed sensors drift out of calibration and fail, so every sensor network requires quality control procedures to promptly detect these failures. To address these problems, we propose a two-level...
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...
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...
We present an approach for generating a character’s response in anticipation of an impending impact. Protective anticipatory movement is built upon several simple actions that have been identified as response mechanisms in monkeys and in humans. These actions are parameterized by a model of the interaction based on the approaching...
This work addresses the application of Nonlinear Model Predictive Control (NMPC) to a class of ocean wave energy conversion systems in which the cost functional is not in a standard quadratic form, and the WEC model includes the nonlinear effects, such as the hydrodynamic viscous drag. The NMPC implementation is...
As a general solution to the problem of managing structural and content variability in relational databases, in previous work we have introduced the Variational Database Management System (VDBMS). VDBMS consists of a representation of a variational database (VDB) and a corresponding typed query language (v-query). However, since this is a...
The US military is evaluating the capabilities of emerging technologies based on IEEE 802.16 standard as a potential commercial off-the-shelf solution to support the communication requirements of the future war.
In the last few years, development in military and telecommunication industries have focused on an intensive use of broadband systems,...
The topic of species distribution modelling has been on of increasing interest in
recent years. As climate change is becoming of even more interest to researchers,
more tools are needed to better analyze and predict various climate change scenarios.
One particular area of interest is that of species distribution modeling....
Magnetic materials can be used in modern soft robotics as a method for external stimulus actuation and motion control. By combining aspects of biology and mechanics, devices are fabricated to create a structure capable of complex movement. Applications that these devices are subject to can be broken down into four...
The quality of a digital image pipeline relies greatly on its color reproduction which should at a minimum handle the color constancy, and the final judgment of the excellence of the pipeline is made through subjective observations by humans.
This dissertation addresses a few topics surrounding the color processing of...
Tensor mathematics provides a powerful language to visualize and analyze physical phenomena. In the last three decades, tensors have been used in various application areas. The visualization and analysis of tensors fields have seen much advance, both in 2D and 3D. However, the physical interpretations of the topological analysis are...
Urban green space is associated with multiple physical and mental health outcomes. Several benefits of green space, such as stress reduction and attention restoration, are dependent on visual perception of green space exposures. However, traditional green space exposure measures do not capture street-level exposures. In this project, we apply deep...
This dissertation explores the idea of applying machine learning technologies to help computer users find information and better organize electronic resources, by presenting the research work conducted in the following three applications: FolderPredictor, Stacking Recommendation Engines, and Integrating Learning and Reasoning.
FolderPredictor is an intelligent desktop software tool that helps...
In the ever-evolving field of computer science (CS) education, the significance of teachers and their backgrounds have often been overshadowed by the predominant focus on students. Teachers in the K-12 often lack the necessary expertise and have limited support provided by existing CS-based curricula. While research on CS education effectiveness...
There are growing interests in designing polynomial-time approximation schemes (PTAS) for optimization problems in planar graphs. Many NP-hard problems are shown to admit PTAS in planar graphs in the last decade, including Steiner tree, Steiner forest, two- edge-connected subgraphs and so on. We follow this research line and study several...
Modern datacenters are constructed with multirooted tree topologies and support multiple service queues per switch port. They support a wide variety of applications and services with stringent performance needs and conflicting requirements. To meet these requirements, recent works focus on load balancing or ECN marking approaches. Though existing load-balancing approaches...
This project is a custom output stage for a two-channel signal source design project at Oregon State. Starting in January, I began leading a team tasked with the development of an arbitrary waveform generator via the CreateIT Collaboratory at OSU. Undergraduate students interview into the CreateIT Collaboratory and are assigned...
Delta-sigma analog-to-digital converters (ADCs) are suitable for many applications due to several advantages such as relaxed anti-aliasing filter, high signal-to noise and distortion ratio (SNDR) and most important of all, reduced sensitivity to
analog imperfections.This thesis introduces several structures to overcome loop imperfections and stability issues in delta-sigma modulators. First,...
For today’s ubiquitous portable devices, innovative integrated circuits with high performance
yet very low power are necessary. As these devices are used to communicate and sense real world signals in the environment, analog-to-digital converters (ADC) and systems are the key interface circuits needed to digitize the sensed information and they...
Analog-to-Digital Data Converters (ADCs) used in instrumentation and measurements often require high absolute accuracy, including excellent linearity and negligible dc offset. Incremental data converters (IDCs) provide a solution for such measurement applications. Since IDCs are essentially delta-sigma converters with reset operation before each conversion, they retain most of the advantages...
Throughput-oriented processors, such as graphics processing units (GPUs), have been increasingly used to accelerate general purpose computing, including machine learning models that are being utilized in numerous disciplines. Thousands of concurrently running threads in a GPU demand a highly efficient memory subsystem for data supply in GPUs. In this dissertation,...
Most of today’s Internet of Things (IoT) applications assume that data will be moved offdevices into centralized cloud platforms. While existing IoT systems leverage cloud-based analytics for meaningful data reasoning, the assumption that data should always be moved off the devices is problematic. The amount of data to be moved...
With the advent of Artificial Intelligence (AI) in every sphere of life in today's day and age, it has become increasingly important for non-AI experts to be able to comprehend the underlying logic of how AI systems work, assess them and find faults in these systems, particularly when they are...
While there are many ways to evaluate a user interface design, the user's mental workload and situation awareness (SA) are particularly important considerations in the supervisory control of safety-critical systems. Typically, operators of these systems must monitor high-volume, time-sensitive status information. Interface design for this domain can be challenging and...
Programmers often have to choose components online for reuse based on software quality. To help with this choice, most component repositories (SourceForge, CodeProject, etc.) provide information such as user ratings and reviews of components. However, the reusability of components is not immediately obvious from
this material. To make things worse,...
As scaling of silicon (Si) based devices approaches fundamental limits, thin film metal-insulator-metal (MIM) tunnel diodes are attracting interest due to their potential for high speed operation. Because operation of these devices is based on tunneling, electrode / interfacial roughness is critical. Recently, it was shown that combining ultra-smooth bottom...