The sliding mode controller, based on the theory
of the Variable Structure System (VSS), is considered
for a robot manipulator. By consideration of VSS theory,
the nonlinear interactions of manipulator dynamics
are suppressed by use of linear sliding equations, and
VSS robustness with respect to the unknown physical manipulator
parameter...
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...
Multiple wave energy converter (WEC) archetypes exist with varying power take-off (PTO) designs in the attempt to maximize ocean energy harnessed and converted into useful energy. The pendulum PTO is popular for its simple, yet robust functionality due to its internally located components and simple operation. Additionally, this PTO does...
The amount of instruction level parallelism (ILP) that can be exploited depends
greatly on the size of the instruction window and the number of in-flight instructions
the processor can support. However, this requires a register file with a large set of
physical registers for renaming and multiple ports to provide...
This work presents a high-resolution Delta-Sigma ADC which combines the use of the pseudo-pseudo-differential noise filtering technique with single-ended ring amplifier based integrators. The pseudo-pseudo-differential noise filtering technique utilizes single-ended circuits while maintaining the even-order rejection found in fully-differential structures which alleviates, in the active analog blocks, the need for...
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...
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...
Strategies for simulation and measurement of substrate noise have been analyzed using various digital and analog circuits fabricated in the TSMC 0.35um heavily doped CMOS process. The measurements validate a substrate noise coupling macromodel that has been used to obtain the simulation results. The simulations and measurements also substantiate the...
Efficient routing of messages is critical to the performance of multicomputers. Many adaptive routing algorithms have been proposed to improve the network efficiency; however, they can make only short-sighted decisions to choose a channel for message routing because of limited information about network condition. The short-sighted decisions may cause unnecessary...
In high voltage direct current(HVDC) systems
transmission technology, a.c. power is
converted(rectified) to d.c. power by means of a
controlled rectifier bridge. This d.c. power is then
transmitted through a d.c. link to another
converter(inverter) where it is converted back to a.c.
power by means of another controlled rectifier bridge....
Efficient methods for simulating the substrate noise generated by complex synchronous and asynchronous digital logic circuits are presented. By simulating digital logic at the gate level, and precharacterizing the gates, the substrate noise generation can be predicted and used in a transistor level simulation of the sensitive analog blocks. This...
This project examines the results of current-voltage conduction mechanism analysis techniques simulated under assumed conduction conditions. Thermionic emission and Fowler-Nordheim tunneling conditions are simulated and analyzed. The resulting plots show how devices behave under different condition mechanisms. The effects of different conduction mechanisms on the results of various analysis techniques...
Within the past decade, the continued-scaling of CMOS processes and improvements in industry mixed-signal integrated-circuit designs have enabled a rapid decrease in the cost, form-factor, and power for point-of-care diagnostics and electrochemical instrumentation. Similarly, advances in low-power RF designs have prompted entire System-on-Modules supporting widely varied Internet-of-Things (IoT) applications. The...
Electroanalytical techniques allow scientists and engineers to characterize bulk solutions as well as interfaces. Potentiostats are commonly used by researchers in a variety of disciplines to analyze the chemistry which occurs at a working electrode surface. Advancements in microelectronics and the proliferation of open-source designs have allowed researchers to construct...
The primary objective of a grid is to maintain a balance between generation and load. If these quantities are not in balance with each other, severe damages such as voltage fluctuations, low power quality, power outages or even cascaded blackouts may occur. Hence one of the primary factors that holds...
The order of the practical system (e.g. nuclear power
plants, electrical power network and chemical plant) is
quite large. However, there are many limitations in computing
facilities for the large system. Because of these
limitations, it is often necessary to reduce the order of
the large system using an approximation....
Silicon photonics has rapidly become one of the most promising photonic integration platforms. Especially, microring resonator (MRR) plays a pivotal role in silicon photonics and has been widely used for electro-optic (E-O) modulators and wavelength filters due to its small footprint, low energy consumption, and high quality factor (Q-factor). Recently,...
This thesis presents Silencer!, a fully automated, schematic-driven tool for substrate noise coupling simulation and analysis. It has been integrated in the CADENCE DFII environment and seamlessly enables substrate coupling analysis in a standard mixed-signal design flow. Silencer! aids IC designers in the analysis of substrate noise coupling at different...
The Advent of multi-cores allows programs to be executed much faster than before. Cryptoalgorithms use long-bit words thus parallelizing these operations on multi-cores will achieve significant performance improvement. However, not all long-bit word operations in cryptosystems are suitable for parallel execution on multi-cores. In particular, long-bit words used in Elliptic...
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...
Powerline communication (PLC), is becoming a more commonplace method for data transmission, however it is still a very new medium for data transmission, and international standards for powerline communication are still in the process of being developed and established. PLC can provide a means of simplifying the device connectivity to...
Due to advances in high-density low-cost VLSI and communication technology,
digital filtering and signal processing are being widely used for real-time signal processing
applications. Given the filter specification, choosing the best filter structure for a given
application is not a trivial task. The choice of a particular filter structure depends...
Phase Locked Loops(PLLs) are an integral part of almost every electronic system. Systems involving low frequency clocks often require PLLs with low bandwidth. The area occupied by the large loop filter capacitor and resistor in a low bandwidth PLL design makes the realization of traditional charge-pump PLL architecture impractical on...
Network coding, as the next generation of data routing protocols, enables each intermediate node in a network to process and encode its received data before forwarding it to the next nodes. Hence, the core idea in network coding is to allow a network to encode the data that is being...
Instant Messaging (IM) has grown rapidly among network users. It has even become a very important tool for the industry around the world. It is used in scheduling meetings, exchanging business information and clients information, and so on. Instant Messaging has been developed by private sectors or providers such as...
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...
As the fifth generation of mobile communication systems (5G) is being deployed, massive multiple-input multiple-output (MIMO) serves as one of its enabling technologies where reliable and ultra low latency communications are achieved while being power and spectrum efficient. This thesis studies the security aspect of massive MIMO system from the...
Many systematic methods exist for mapping algorithms to processor arrays. The algorithm is usually specified as a set of recurrence equations, and the processor arrays are synthesized by finding timing and allocation functions which transform index points in the recurrences into points in a space-time domain. The problem of scheduling...
Accurate scaled modeling and simulation are critical to advancing ocean wave linear generator buoys. A 100th scaled model of ocean wave generator buoy systems is analyzed by solving the Navier-Stokes equations. These equations are numerically solved using Computational Fluid Dynamics (CFD) by implementing the front capturing method. In this thesis,...
Scalable array transceivers with wide frequency tuning range are attractive for next-generationradios. Key challenges for such radios include generation of LO signals with widefrequency tuning range, scalable synchronization between multiple array unit cells andtolerance to in-band and out-of-band interferers. This thesis presents approaches toaddress these challenges in commercial CMOS technologies.The...
The purpose of the thesis is to synthesize the major results of a continuous
research effort directed toward new applications of high speed sampling in general and Electrooptic Sampling in particular.
Equivalent time sampling of repetitive high speed signals continues to provide significant performance enhancements for present and future generations...
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...
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...
Demands of today's integrated society dependent on communication systems have driven the creation of ever more efficient analog-to-digital converters. For the same reasons, digital circuitry has rapidly expanded to serve all the different systems and needs of consumers. The trend of technology development has been to make these digital circuits...
A comprehensive and scalable solution for high-performance switched capacitor amplification is presented. Central to this discussion is the concept of ring amplification. A ring amplifier is a small modular amplifier derived from a ring oscillator that naturally embodies all the essential elements of scalability. It can amplify with accurate rail-to-rail...
Wireless power transfer (WPT) is a way to transfer power from one device to another without any wire or cable connections. Although the technology has been around for more than 100 years, it is gaining popularity in recent years due to the ever-increasing demand for faster and more frequent charging...
Spectrum overcrowding, ever increasing demand for high data rate and increased mobility requirements are three major challenges 5G-technology is trying to address. In this thesis I start with a RF front-end technique that deals with blocker interference arising from spectrum overcrowding both across frequency bands and within the same frequency...
The problem of the restoration of quadratically
distorted images is considered in this investigation, based
upon the fact that images formed by partially coherent
illuminations are related quadratically to the amplitude of
the object. Two of the most important problems in image
restoration are: 1) determining the degradation
characteristics of...
We studied the problem of resource allocation in large scale distributed applications such as Online Social Networks (OSN) and Cloud Computing. In such settings, resource allocation schemes need to efficient as well as adaptive to the time-varying environments. The abstract resource allocation problem concerns with how to optimally use resources...
The increased use of mobile wireless devices that we have recently been witnessing, such as smartphones, tablets, e-readers, and WiFi enabled devices in general, is driving an unprecedented increase in the amount of data traffic. This fast market adoption of the wireless technology along with the tremendous success of multimedia...
Previous work at Stanford University has demonstrated that inductance in the
substrate connection is the principal problem underlying the coupling of digital
switching noise into analog circuits. The low impedance substrate can be treated
as a single node over a local area. Switching in the digital circuits produces
current transients...
The resolution of analog-to-digital converters can be distinguished as absolute resolution, or average resolution. This study reviews average resolution enhancement techniques and proposes a method which is particularly applicable as a low-cost modification to a high-speed waveform acquisition system. This method uses oversampling combined with computationally simple digital filtering to...
The United States depends on the electrical grid infrastructure for nearly every facet of its operation. Understanding how inclement weather affects the reliability of the grid and what the U.S. is doing to ensure its resiliency will be a key step moving forward into the 21st century as global climate...
Renewable electrical energy sources are relatively easy to integrate at moderate penetrations, utilizing a combination of technical and market methods to increase grid flexibility. However, integrating high renewable portfolios is more challenging, and the optimal combination of resources will vary depending on the features of specific geographic areas. This study...
Disk space fragmentation is the proliferation of small and
unusable gaps. This problem is considered within the context of
IBM's VM operating system.
Facing this problem, researchers resorted to using algorithms
based on memory management techniques, such as placement
strategies (first-fit, best-fit, and worst-fit). Solutions based on these
algorithms do...
Reliable controller designs have been developed in this thesis for a number of finite-horizon
and infinite-horizon problems with possibly non-zero initial conditions. These
reliable controllers assure that system stability and system performance will be
maintained despite certain system faults. The performance measure used in this thesis is
an "H[subscript ∞]-like...
Reliability of sub-micron analog circuits is directly related to impact ionization and
the subsequent changes in threshold voltage and drain current of n-MOSFET devices.
This thesis presents theory of the hot-electron effects on the device characteristics and
circuit performance, explores several approaches to improve performance at both the
device and...
REGTRAN (REGister TRANsfer), a hardware description
language and SYSSIM (SYStems SIMulation), a simulator for the
system described by REGTRAN were originally developed by Edward
Pett, Jr [33] at the University of Texas at Austin. These two programs
are successfully used to simulate many digital systems of
complex nature. It is...
This thesis describes the design of a Reduced Instruction Set Computer. Its instruction memory utilizes a unique cache architecture and a two-stage memory pipelining technique. Because of the bandwidth of the 64-bit instruction bus, instruction prefetching is possible and is implemented. The data memory is bridged by a four-way set-associative...