Electrical and Computer Engineering Commons^™

Surface Analysis Of Materials For Direct Wafer Bonding, Arif Ul Alam

Open Access Dissertations and Theses

Surface preparation and its exposure to different processing conditions is a key step in heterogeneous integration of electronics, photonics, fluidics and/or mechanical components for More-than-Moore applications. Therefore, it is critical to understand how various processing and environmental conditions affect the surface properties of bonding substrates. In this thesis, the effects of oxygen reactive-ion etching (O₂ RIE) plasma followed by storage in ambient and 98% relative humidity on some key surface properties such as roughness, water contact angle, hardness, and the elemental and compositional states of three materials – silicon (Si), silicon dioxide (SiO₂) and glass – are investigated to ...

Dynamics-Based Invariants For Video Analytics, Binlong Li

Electrical Engineering Dissertations

Cameras are ubiquitously everywhere and hold the promise of significantly changing the way we live and interact with our environment. A major roadblock to achieve this potential is the curse of dimensionality: often the actionable information is a very small fraction of a vast amount of data, which is difficult to extract in real-time. In this thesis we propose to address this issue by exploiting dynamics-based invariants as an information encapsulating paradigm. The approach is inspired by the fundamental fact that visual data comes in streams: videos are temporal sequences of frames, images are ordered sequences of rows of pixels ...

Power System Dynamic State Estimation And Load Modeling, Cem Bila

Electrical and Computer Engineering Master's Theses

State estimation which constitutes the core of the Energy Management System (EMS), plays an important role in monitoring, control and stability analysis of electric power systems. An efficient, timely and accurate state estimation is a prerequisite for a reliable operation of modern power grids.

Traditional state estimators, which are based on steady state system model, cannot capture the system dynamics very well due to the slow updating rate of SCADA systems. In mid 1980s of the 20^th century, Phasor Measurement Unit (PMU)-based Wide-Area Measurement Systems (WAMS) emerged. The introduction of this high speed measurement systems, featured with synchronous ...

Variable Precision Floating Point Reciprocal, Division And Square Root For Major Fpga Vendors, Xin Fang

Electrical and Computer Engineering Master's Theses

Variable precision floating point operations have various fields of applications including scientific computing and signal processing. Field Programmable Gate Arrays (FPGAs) are a good platform to accelerate such applications because of their flexibility, low development time and cost compared to Application Specific Integrated Circuits (ASICs) and low power consumption compared to Graphics Processing Units (GPUs). Increasingly scientists are interested in variable precision floating point operations not limited to single or double precision operations implemented on FPGAs, in order to make those operations more resource efficient and more suited to their own applications.

Among those operations, the performance of reciprocal, division ...

Transient Analysis Of An Electrostatically Tunable Multiferroic Inductor, Carl Joseph Hansen

Electrical and Computer Engineering Master's Theses

This thesis examines the dynamic behavior of an electric-field tunable multiferroic inductor, a four-terminal device that is comprised of a two-terminal variable inductor with an inductance controlled by a two-terminal voltage input. Although the inductor features a wide tuning range and high quality factor, little information is available regarding the inductor's transient characteristics in response to a fast changing control voltage. Therefore, its role in certain high-speed electronic applications is currently undetermined.

To reduce the aforementioned knowledge gap, the time-varying tuning response of the multiferroic tunable inductor is explored in this thesis to establish its relevance to high-speed electronics ...

Target Localization And Tracking In A Random Access Sensor Network, Kivanc Kerse

Electrical and Computer Engineering Master's Theses

Wireless Sensor Networks (WSNs) are commonly used to monitor physical or environmental parameters such as temperature, sound, velocity, etc. Such networks find application in different areas including military, environmental, medical and industrial ones. For applications that require long term monitoring, data collection with limited resources (power, bandwidth) is a challenging problem. In addressing these challenges, we study a network architecture that relies on integrating sensing and random channel access to achieve energy efficiency. Specifically, this thesis focuses on the use of WSNs for target localization and tracking. In a random access framework, distributed sensor nodes transmit data packets to the ...

Robust Dynamic State Estimator Accounting For Load Changes, Alireza Rouhani

Electrical and Computer Engineering Master's Theses

Load models are commonly approximated by fixed impedance type loads when formulating dynamic simulations. This is an acceptable approximation when using dynamic simulation for a specific initial operating condition and the study runs for a brief period typically to check system stability. When implementing an on-line dynamic estimator such assumptions may not be viable due to the load dynamics which are not typically known.

Unlike previous studies reported in literature, this work takes into account the effect of changes in bus loads on dynamic state estimation. Two methods are proposed to address this problem, in the first method the performance ...

Self-Biased Circulators For High Power Applications, Alexander S. Sokolov

Electrical and Computer Engineering Master's Theses

Self-biased circulators exploit the properties of high anisotropy magnetic field in hexagonal ferrites, thus allowing operation without biasing magnets and a significant size and weight reduction. Although first self-biased circulators were demonstrated more than 20 years ago, all the prototypes constructed so far are unsuitable for practical applications.

An attempt to design a self-biased circulator from scratch was made. Novel exceptionally low dielectric loss and high heat conductivity ceramic materials were developed and innovative substrate synthesis techniques were employed. Low temperature cofiring of green body ferrite compacts and dielectric ceramic slurries were mastered, resulting in solid composite substrates.

Original device ...

Efficient Lossy Ultraspectral Data Compression: Hybrid Predictive Transform Coding Algorithm, Deqi Song

Electrical and Computer Engineering Master's Theses

This project proposes a new lossy ultraspectral image compression algorithm, hybrid predictive transform (HPT) coding algorithm. It is based on the predictive coding and the transform coding algorithms. The HPT algorithm consists of four stages: preprocessing, prediction, discrete cosine transformation, and compression protocol. Since the attributes of the ultraspectral data change obviously in the spectral direction, the HPT employs the two predictors, that are used in the partition differential plus-code modulation (PDPCM) and low complexity lossless compression for two-dimensional (LOCO-2D) algorithms, to remove the correlation. When the threshold of spectral correlation is 0.9, the HPT algorithm divides the ultraspectral ...

Physical Design Of A Smart Camera With Integrated Digital Pixel Sensors Using A 0.13Μm 8-Layer Metal Cmos Process, Mahir K. Gharzai

Electrical Engineering Theses and Dissertations

The design of cameras has historically kept imagery and computational circuitry isolated in an attempt to maximize image quality by improving pixel pitch and routing density. Although this technique has worked in creating high density arrays of pixels for large resolution imagers, it has never been able to achieve high framerate computational operations.

A radical approach is introduced to solve this dilemma by creating compact, low- power pixel elements with built-in analog-to-digital converters that directly interface with digital logic. These pixels are capable of integrating alongside logic cells and to create an array of pixels inside the processor that can ...

Cmos Smart Camera With Focal Plane Neighborhood-Parallel Image Processing, Joseph A. Schmitz

Electrical Engineering Theses and Dissertations

A neighbhorhood-based smart camera architecture is designed and implemented in a 0.13 μm CMOS technology. Each 8 × 8 region of pixels contains a small processor with local memory, which are tiled to form a full-resolution camera. Each processor operates in parallel, enabling high-speed image processing suitable for tracking and recognition tasks. The architecture features the programming flexibility of designs us- ing chip-level and row-level processors while preserving the scalability of pixel-parallel processing elements. The neighborhood processors are implemented physically be- tween the pixel photodiodes, creating multiple design challenges that are discussed in detail.

Advisors: Sina Balkir and Michael Homan

Frequency, Radiation Pattern And Polarization Reconfigurable Antenna Using A Parasitic Pixel Layer, D. Rodrigo, Bedri A. Cetiner, L. Jofre

ECE Faculty Publications

The ultimate goal of antenna reconfigurability is the development of antenna structures that can independently adjust their operation frequency, radiation pattern and polarization. This paper presents a significant advancement towards this objective. A switched grid of small metallic patches, known as pixel surface, is used as a parasitic layer that can provide reconfiguration capabilities to existing antennas acting as driven element. A fully operational prototype has been designed, fabricated and its compound reconfiguration capabilities have been thoroughly characterized. The prototype combines a patch antenna operating at 2.5 GHz and a parasitic pixel surface consisting of 6x6 pixels, with an ...

Impact Of Plug In Electric Vehicle Battery Charging On A Distribution System Based On Real-Time Digital Simulator, Abdulelah Yousef Alharbi

Theses and Dissertations

This study investigates the impact of the electric vehicles (EVs’) battery charging on the distribution system in terms of maximum voltage deviation, voltage unbalance at various locations, transformers overloading, and introducing new peaks into the system. In this research, a 12.47 kV real distribution network has been modeled using real time digital simulator, using real data from a power distributor. The study presents four different scenarios of uncoordinated EVs integration for two different charging times (evening and night) and two different charging rates (level I and level II) at different penetration levels ranging from 10% to 100%. Voltage unbalance ...

A Study On Countermeasures Against Steganography: An Active Warden Approach, Qilin Qi

Dissertations & Student Research in Computer Electronics & Engineering

Digital steganography is a method used for hiding information in digital images. It can be used for secure communication. There have been many robust digital steganography methods invented in recent decades. The steganographic message can be inserted in multimedia cover signal such as audio, image and video. However, this technique also may be used by malicious users to transmit dangerous information through the Internet beyond the control of security agencies. How to detect and/or block potentially dangerous information transmission on the Internet through billions of multimedia files while not affecting innocent multimedia communications becomes a challenging problem. Existing steganalysis ...

Spectrum Sensing And Multiple Access Schemes For Cognitive Radio Networks, Oscar G. Filio Rodriguez

University of Western Ontario - Electronic Thesis and Dissertation Repository

Increasing demands on the radio spectrum have driven wireless engineers to rethink approaches by which devices should access this natural, and arguably scarce, re- source. Cognitive Radio (CR) has arisen as a new wireless communication paradigm aimed at solving the spectrum underutilization problem. In this thesis, we explore a novel variety of techniques aimed at spectrum sensing which serves as a fundamental mechanism to find unused portions of the electromagnetic spectrum.

We present several spectrum sensing methods based on multiple antennas and evaluate their receiving operating characteristics. We study a cyclostationary feature detection technique by means of multiple cyclic frequencies ...

Modeling And Protection Of Phase Shifting Transformers, Umar Khan

University of Western Ontario - Electronic Thesis and Dissertation Repository

This thesis is mainly focused on the development of (i) phase shifting transformers (PSTs) mathematical and simulation models that can be used for the short-circuit and protection studies, and (ii) new phase shifting transformers protection methods that provide more secure and sensitive solutions than the standard current differential protection.

The first part of this thesis describes and presents the modeling of the single-core standard-delta, and two-core symmetrical and asymmetrical PST for protection and short-circuit studies. The models already available for such types of PSTs have limitations and require detailed test report data from the manufacturers. However, winding test data at ...

Wireless Networks: Technological Challenges And Policy Implications, Christopher S. Yoo

Faculty Scholarship

Since June 2012, mobile wireless has emerged as the largest and fast growing medium for broadband service. At the same time, mobile wireless networks have proven considerably more difficult to manage than wireline networks. The primary causes are the rapid growth in demand for wireless bandwidth and the greater susceptibility of wireless networks to poor quality of service because of the omnidirectional propagation of wireless signals, bad handoffs, local congestion, and the susceptibility to complex interference patterns caused by multipath propagation. Moreover, the central inference underlying the primary form of congestion management is not valid for wireless networks. As a ...

In-Line Post-Process Scribing For Reducing Cell To Module Efficiency Gap In Monolithic Thin-Film Photovoltaics, Sourabh Dongaonkar, Muhammad A. Alam

Birck and NCN Publications

The gap between cell and module efficiency is a major challenge for all photovoltaic (PV) technologies. For monolithic thin-film PV modules, a significant fraction of this gap has been attributed to parasitic shunts and other defects, distributed across the module. In this paper, we show that it is possible to contain or isolate these shunts using state-of-the-art laser scribing processes, after the fabrication of the series-connected module is finished. We discuss three alternatives, and quantify the performance gains for each technique. We demonstrate that using these techniques, it is possible to recover up to 50% of the power lost to ...

Uncertainty Propagation From Sensing To Modeling And Control In Buildings - Technical Report, Madhur Behl, Truong Nghiem, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

A fundamental problem in the design of closed-loop Cyber-Physical Systems (CPS) is in accurately capturing the dynamics of the underlying physical system. To provide optimal control for such closed-loop systems, model-based controls require accurate physical plant models. It is hard to analytically establish (a) how data quality from sensors affects model accuracy, and consequently, (b) the effect of model accuracy on the operational cost of model-based controllers. We present the Model-IQ toolbox which, given a plant model and real input data, automatically evaluates the effect of this uncertainty propagation from sensor data to model accuracy to controller performance. We apply ...

Web-Based Visual Analytics For Social Media Data, Jun Xiang Tee, David S. Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

Social media data provides valuable information about different events, trends and happenings around the world. Visual data analysis tasks for social media data have large computational and storage space requirements. Due to these restrictions, subdivision of data analysis tools into several layers such as Data, Business Logic or Algorithms, and Presentation Layer is often necessary to make them accessible for variety of clients. On server side, social media data analysis algorithms can be implemented and published in the form of web services. Visual Interface can then be implemented in the form of thin clients that call these web services for ...