This research work focuses on the mechanism of 1/f noise in GaAs
resistors on semi-insulating substrates and 1/f noise due to temperature
fluctuations in heat conduction in resistors, diodes, and bipolar transistors. The
goal of this research is to generate accurate models to explain physical origin of 1/f
noise in...
In many traditional computer graphics applications, rendered scenes typically utilize 3D meshes to represent objects within an environment. As the demand to further improve the realism of graphics applications increases, such as for movies and games, it is becoming more important to represent the inner volumes of object meshes. In...
The sensors in real time data processing IoT devices require high resolution and sub-MHz data converters, usually implemented as Incremental ADCs due to the advantages of oversampling technique and low latency. In discrete time incremental (IDT) ADCs, the sampling switch non-linearity, charge injection degrade the resolution, and power hungry OPAMPs...
Commonly proposed ocean wave energy converters (OWEC) use inefficient and maintenance demanding intermediate hydraulic and pneumatic systems. We propose a novel rotary direct-drive OWEC that eliminates these intermediate stages. The new device employs a contactless force transmission system (CFTS) comprising a “piston” and a “cylinder” and a ball screw to...
With the development of high performance power electronic and semiconductor technologies, Adjustable Speed Drive (ASD) systems are increasingly applied in residential, commercial and industrial applications. Due to the advantages at higher power ratings, the three-level Neutral-Point-Clamped (NPC) Voltage Source Inverter (VSI) is being employed in industrial and traction applications, static...
This dissertation presents a dual-path 2-0 MASH (Multi-stAge-noise -SHaping) ADC with two verified digital corrections of DAC mismatch error and quantization noise leakage. By using these two techniques, the requirements for the analog circuits are greatly relaxed. The dual-path structure generates two outputs, one only composed of conversion errors, the...
Continuous Improvement (CI) of academic computing programs is a main requirement of accreditation. Academic computing programs must have a well-documented CI plan in order to be granted accreditation. Based on the existing literature, we developed a comprehensive CI (or 360-CI) model consisting of 8 components: course, curriculum, administration, faculty, research,...
This thesis proposes a novel fully digital technique for the estimation and correction of the DAC error in multi-bit delta sigma ADCs. The structure of the DAC error is indicated through a simple model for unit-element based DACs. The impact of the DAC error on the performance of ADC is...
The electrical grid is a key component of the Nation's critical infrastructure. Its continuous and reliable operation is of vital importance; any system-wide disruption would have a debilitating impact on crucial services, public health and safety, the economy, and the national security of the United States.
High-impact low-frequency events pose...
Over the last decade the increase in penetration of wind power and its variable nature has begun to add considerable stress to and threatened the stability of the nation's grid. In order to continue growth wind farms will need to have the ability to participate in the same grid frequency...
Digital-to-analog converters (DACs) with wide dynamic range and high
linearity are required for high-end audio applications. A multi-bit delta sigma
audio DAC, using a novel gain-correction technique, is described in this thesis. For
widely varying on-chip RC time constant, the DAC gain can be accurately
controlled by the correction circuitry....
Evolution of the mobile communication standards and proliferation of hand-held devices mandate stringent Analog-to-Digital Converter (ADC) specifications. Among various ADCs, a ∆Σ ADC is best known as a power-efficient ADC when more than 12b is required. However, a conventional discrete-time (DT) ∆Σ Modulator (∆ΣM) is inadequate for low-power wideband applications...
This work presents a novel CCRW receiver that utilizes a window of variable width, for e˙ectively mitigating multipath and ambiguity in both civil and military positioning applica-tions using Global Navigation Satellite Systems (GNSS). This CCRW receiver incorporates a single stroboscopic window, whose width is iteratively reduced until the e˙ect of...
The spread of the internet and communications techniques increases the necessity
for security in applications that involves sharing or exchange of secret or private infor-
mation. Public-key cryptography is widely used in establishing secure communication
channels between the users on the Internet, for E-commerce transactions, and in net-
work security...
Multi-instance data, in which each object (e.g., a document) is a collection of instances
(e.g., word), are widespread in machine learning, signal processing, computer vision,
bioinformatic, music, and social sciences. Existing probabilistic models, e.g., latent
Dirichlet allocation (LDA), probabilistic latent semantic indexing (pLSI), and discrete
component analysis (DCA), have been...
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...
This dissertation presents a phase domain in-loop-bandwidth spread-spectrum clock generation technique. In this proposed technique, a charge-based discrete-time loop filter is proposed to enable the phase domain in-loop-bandwidth spread-spectrum modulation without a delta-sigma modulator or time-to-digital converter. The in-loop-bandwidth modulation technique maximizes the loop bandwidth to improve phase noise suppression...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are widely used in wireless transceivers. Recently, continuous-time (CT) ΔΣ ADCs gain growing interest in wireless applications for their lower power consumption and wider input bandwidth as compared with the discrete-time (DT) counterparts.
In this thesis, a wideband low-power CT ΔΣ modulator for next generation...
The need for sustainably powering unobtrusive internet-of-things applications has led to an interest in energy harvesting. Particularly, the proliferation of wireless communication and devices in the 2.4 GHz Industrial Scientificc Medical (ISM) band creates an opportunity to leverage commonly used devices for RF powering. This dissertation presents a low-quiescent-power...
Pipelined analog to digital converters (ADCs) are very important building blocks in many electronic systems such as high quality video systems, high performance digital communication systems and high speed data acquisition systems. The rapid development of these applications is driving the design of pipeline ADCs towards higher speed, higher dynamic...
In the past few decades, magnetic recording has been used as a dominant solution for massive data storage due to its large capacity, excellent reliability and low cost. Nowadays, exponentially increasing user-generated information is creating a huge demand as well as great challenges for high density data storage solutions. For...
This paper addresses the high model complexity and overconfident frame labeling of state-of-the-art (SOTA) action segmenters. Their complexity is typically justified by the need to sequentially refine action segmentation through multiple stages of a deep architecture. However, this multistage refinement does not take into account uncertainty of frame labeling predicted...
In this dissertation, we address action segmentation in videos under limited supervision. The goal of action segmentation is to predict an action class for each frame of a video. The limited supervision means ground truth labels of video frames are not available in training. We focus on three types of...
Humans are remarkably efficient in learning by interacting with other people and observing their behavior. Children learn by watching their parents’ actions and mimic their behavior. When they are not sure about their parents demonstration, they communicate with them, ask questions, and learn from their feedback. On the other hand,...
Successive-approximation-register (SAR) analog-to-digital converters are popular for medium accuracy, medium speed and low power applications, such as in biomedical applications. They have low latency and simple architecture compared with ΔΣ ADCs. This is because of SAR ADCs’ binary searching scheme. Furthermore, SAR ADCs can apply oversampling and noise shaping schemes...
Knowledge workers are struggling in the information flood. There is a growing interest in intelligent desktop environments that help knowledge workers organize their daily life. Intelligent desktop environments allow the desktop user to define a set of “activities” that characterize the user’s desktop work. These environments then attempt to identify...
Partial programming is a field of study where users specify an outline or skeleton of a program, but leave various parts undefined. The undefined parts are then completed by an external mechanism to form a complete program. Adaptation-Based Programming (ABP) is a method of partial programming that utilizes techniques from...
As the number of mobile devices accessing large-scale WLANs such as campus
and metropolitan area networks increases, the need for load balancing among the
cells becomes crucial. In addition, the network must also support some minimum
handoff tolerance defined by an application.
A number of load balancing techniques have been...
The ubiquity of high quality video and proliferation of mobile devices has contributed to an unprecedented rise in video consumption. HTTP, in conjunction with adaptive streaming, has become the de facto mechanism for delivering the vast majority of video as it readily caters to heterogeneous networks and devices. This dissertation...
The exponential rate of advances in modern communication devices in the last several years have brought us higher levels of functionality and performance as well as reductions in physical size and power consumption. To continue this rate of advancement, next generation systems require wider bandwidth and higher resolution ADCs. Additionally,...
In modern on-chip memories, an increasing demand for higher performance, lower power, reduced area, and improved robustness creates a rising need for advanced microarchitecture and circuit design techniques. Particularly in large-signal multi-ported register files, these advanced design techniques include: (i) multi-banked arrays, (ii) multi-frequency arrays, (iii) multi-bit width gating, (iv)...
Traditionally linear actuator applications are addressed by the use of hydraulic systems. The high maintenance cost and poor reliability will always be the most critical problem in the real applications. Benefited from both the high mechanical advantage of the roll screw and the simple structure of the switched reluctance motor,...
The appropriate separation of concerns is a fundamental engineering principle. A concern, for software developers, is that which must be represented by code in a program; by extension, separation of concerns is the ability to represent a single concern in a single appropriate programming language construct. Advanced separation of concerns...
This dissertation proposes the use of advanced time-varying approaches for modeling the dynamics of the multipath channel in wireless communication networks. These advanced time-varying approaches include linear Kalman innovation models in observable block companion form, and neural network-based models. The e˙ectiveness of these type of models is evaluated through three...
Preventative methods for software reverse engineering have been given greater attention in recent times due to the increase in computational resources and tools available to the public. The inherent security provided by encoding source into machine code (executable form) can no longer be assumed, given the availability of effective automated...
Cryptographic devices leak timing and power consumption information that is easily measurable, radiation of various levels, and more. Such devices also have additional inputs, other than plaintext and keys, like voltage, which can be modified to force the device to produce certain faulty outputs that can be used to reveal...
Simultaneous translation, which translates concurrently with the source language speech, is widely used in many scenarios including multilateral organizations. However, it is well known to be one of the most challenging tasks for humans due to the simultaneous perception and production in two languages. On the other hand, simultaneous translation...
Global Positioning Systems have allowed for precise timing of power system measurements over wide areas. This newly found capability has the potential to provide much greater insight into the operation of the power system and its response to contingencies, but few analytical techniques currently exist that provide enough robustness and...
Within the past several years the technology of high-throughput sequencing has transformed the study of biology by offering unprecedented access to life's fundamental building block, DNA. With this transformation's potential a host of brand-new challenges have emerged, many of which lend themselves to being solved through computational methods. From de...
The Internet of Things (IoT) paradigm brought an ever-increasing dependence on low-power devices to collect sensor data and transmit that information to the cloud, placing greater demand on connectivity and lifespan. In response, rapid worldwide innovation demonstrates the trade-offs in processing, communication, and energy consumption with diverse approaches to low-power...
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 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...
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...
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...
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...
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...