Defense Notices


All students and faculty are welcome to attend the final defense of EECS graduate students completing their M.S. or Ph.D. degrees. Defense notices for M.S./Ph.D. presentations for this year and several previous years are listed below in reverse chronological order.

Students who are nearing the completion of their M.S./Ph.D. research should schedule their final defenses through the EECS graduate office at least THREE WEEKS PRIOR to their presentation date so that there is time to complete the degree requirements check, and post the presentation announcement online.

Upcoming Defense Notices

Jennifer Quirk

Aspects of Doppler-Tolerant Radar Waveforms

When & Where:


Nichols Hall, Room 246 (Executive Conference Room)

Committee Members:

Shannon Blunt, Chair
Patrick McCormick
Charles Mohr
James Stiles
Zsolt Talata

Abstract

The Doppler tolerance of a waveform refers to its behavior when subjected to a fast-time Doppler shift imposed by scattering that involves nonnegligible radial velocity. While previous efforts have established decision-based criteria that lead to a binary judgment of Doppler tolerant or intolerant, it is also useful to establish a measure of the degree of Doppler tolerance. The purpose in doing so is to establish a consistent standard, thereby permitting assessment across different parameterizations, as well as introducing a Doppler “quasi-tolerant” trade-space that can ultimately inform automated/cognitive waveform design in increasingly complex and dynamic radio frequency (RF) environments. 

Separately, the application of slow-time coding (STC) to the Doppler-tolerant linear FM (LFM) waveform has been examined for disambiguation of multiple range ambiguities. However, using STC with non-adaptive Doppler processing often results in high Doppler “cross-ambiguity” side lobes that can hinder range disambiguation despite the degree of separability imparted by STC. To enhance this separability, a gradient-based optimization of STC sequences is developed, and a “multi-range” (MR) modification to the reiterative super-resolution (RISR) approach that accounts for the distinct range interval structures from STC is examined. The efficacy of these approaches is demonstrated using open-air measurements. 

The proposed work to appear in the final dissertation focuses on the connection between Doppler tolerance and STC. The first proposal includes the development of a gradient-based optimization procedure to generate Doppler quasi-tolerant random FM (RFM) waveforms. Other proposals consider limitations of STC, particularly when processed with MR-RISR. The final proposal introduces an “intrapulse” modification of the STC/LFM structure to achieve enhanced sup pression of range-folded scattering in certain delay/Doppler regions while retaining a degree of Doppler tolerance.


Past Defense Notices

Dates

MAHMOOD HAMEED

Nonlinear Mixing in Optical Multicarrier Systems

When & Where:


246 Nichols Hall

Committee Members:

Ron Hui, Chair
Shannon Blunt
Erik Perrins
Alessandro Salandrino
Tyrone Duncan

Abstract

Efficient use of the vast spectrum offered by fiber-optic links by an end user with relatively small bandwidth requirement is possible by partitioning a high speed signal in a wavelength channel into multiple low-rate subcarriers. Multi-carrier systems not only ensure optimized use of optical and electrical components, but also tolerate transmission impairments. The purpose of this research is to theoretically and experimentally study mixing among subcarriers in Radio-Over-Fiber (RoF) and direct detections systems. 
For an OFDM-RoF system, we present a novel technique that minimizes the RF domain signal-signal beat interference, relaxes the phase noise requirement on the RF carrier, realizes the full potential of the optical heterodyne technique, and increases the performance-to-cost ratio of RoF systems. We demonstrate a RoF network that shares the same RF carrier for both downlink and uplink, avoiding the need of an additional RF oscillator in the customer unit. 
For direct detection systems, we propose theoretical and experimental investigation of impact of semiconductor optical amplifier nonlinearities on Compatible-SSB signals. As preliminary work, we present experimental comparison of performance degradation of coherent optical OFDM and single carrier Nyquist pulse modulated systems in a nonlinear environment. Furthermore, analysis of distribution properties of optical phases driving a dual-drive MZM and their dependence on scaling factor are proposed for Compatible-SSB modulation format through simulations and experimental results. An optimum scaling factor needs to be found that minimizes residual sideband and signal-signal beat interference in such systems. 


JAY FULLER

Scalable, Synchronous, Multichannel DDS System for Radar Applications

When & Where:


129 Nichols

Committee Members:

Carl Leuschen, Chair
Prasad Gogineni
Fernando Rodriguez-Morales
Zongbo Wang

Abstract

The WFG2013 project uses Analog Devices AD9915 DDS ICs at up to 2.5 GS/s as basic building blocks for a scalable,synchronous, multichannel DDS system. Four DDS ICs are installed on a daughterboard with an Altera Cyclone 5E FPGA as a controller. The daughterboard can run standalone (Solo), in conjunction with another daughterboard (Duo), or N daughterboards surfing a motherboard (Mucho). 

Synchronization between configured DDS ICs is achieved via the on-chip SYNC-IN and SYNC-OUT signals. The master DDS (only one per configuration) generates the SYNC_OUT signal, which is distributed to the SYNC_IN pins on all DDS ICs, including the master. The synchronization signal distribution network was designed to minimize skew such that the SYNC_IN signal reaches the all DDSs at virtually the same time. Even if some skew appears, the AD9915's SYNC_IN and SYNC_OUT signals have adjustable delay. The SYNC_IN signal causes the DDSs to assume a known state. Because all of the DDSs reach the same state at the same time, they are, by definition synchronized.


MOIZ VIRANI

Implementing Websockets in Kansas-Comet for Real-Time Communication in Applications Like Blank-Canvas

When & Where:


1136 Learned Hall

Committee Members:

Andy Gill, Chair
Perry Alexander
Prasad Kulkarni


Abstract

Websockets is a protocol that provides a full-duplex communication channel over a single TCP connection between a web server and web client. Kansas-comet is long polling solution that allows web servers written in the functional programming language Haskell to push data to browser clients. Implementing kansas-comet with websockets enables pushing data from web servers to clients with reduced data loads and network latency, which helps in scaling web applications. Other applications, like the graphics library blank canvas, use kansas-comet, so improving kansas-comet also improves these applications as well. 

In this project, we add websockets to kansas-comet for the sake of improving client-server communications by providing a modern full duplex communication channel. Modern web browsers support the websocket protocol but it is important for kansas-comet to also provide backward compatibility. So, the new kansas-comet now implements a mechanism that falls back to long polling strategy when browser does not support websocket or when applications using kansas comet does not implement websockets. We use JavaScript and the kansas-comet JavaScript library on client browsers, and we use websocket, wai-websockets and warp libraries on the server side to implement websockets in kansas comet.


DANIEL MUCHIRI

Energy-Efficiency of Cooperative MIMO Wireless Systems

When & Where:


2001B Eaton Hall

Committee Members:

Lingjia Liu, Chair
Chris Allen
Erik Perrins
Sarah Seguin

Abstract

Increasing focus on global warming has challenged the scientific community to develop ways to mitigate its adverse effects. This is more so important as different technologies become an integral part of daily human life. Mobile wireless networks and mobile devices form a significant part of these technologies. It is estimated that there are over four billion mobile phone subscribers worldwide and this number is still growing as more people get connected in developing countries. In addition to the growing number of subscribers, there is an explosive growth in high data applications among mobile terminal users. This has put increased demand on the mobile network in terms of energy needed to support both the growth in subscribers and higher data rates. The mobile wireless industry therefore has a significant part to play in the mitigation of global warming effects. To achieve this goal, there is a need to develop and design energy efficient communication schemes for deployment in future networks and upgrades to existing networks. This is not only done in the wireless communication infrastructure but also in mobile terminals. In this project a practical power consumption model which includes circuit power consumption from the different components in a transceiver chain is analyzed. This is of great significance to practical system design when doing energy consumption and energy efficiency analysis. The proposed power consumption model is then used to evaluate the energy efficiency in the context of cooperative Multiple Input Multiple Output(MIMO)systems.


MASUD AZIZ

Navigation for UAVs Using Signals of Opportunity

When & Where:


2001B Eaton Hall

Committee Members:

Chris Allen, Chair
Shannon Blunt
Ron Hui
Heechul Yun
Shawn Keshmiri

Abstract

The reliance of Unmanned Aerial Vehicles (UAVs) on Global Navigation Satellite System (GNSS) for autonomous operation represents a significant vulnerability to their reliable and secure operation due to signal interference, both incidental (e.g. terrain shadowing, ionospheric scintillation) and malicious (e.g. jamming, spoofing). An accurate and reliable alternative UAV navigation system is proposed that exploits Signals of Opportunity (SOP) thus offering superior signal strength and spatial diversity compared to satellite signals. Given prior knowledge of the transmitter's position and signal characteristics, the proposed technique utilizes triangulation to estimate the receiver's position. Dual antenna interferometry provides the received signals' Angle of Arrival (AoA) required for triangulation. Reliance on precise knowledge of the antenna system's orientation is removed by combining AoAs from different transmitters to obtain a differential Angles of Arrival (dAoAs). Analysis, simulation, and experimental techniques are used to characterize system performance; a path to miniaturized system integration is also presented.


SASANK REDDY

Evaluation of an Equivalent Electrical Circuit Model Predicting the Battery Characteristics

When & Where:


2001B Eaton Hall

Committee Members:

Ron Hui, Chair
Joseph Evans
Jim Stiles


Abstract

Batteries are used everywhere and with the rise of the portable devices it is crucial to lower the power dissipation and to improve the battery runtime. An efficient way to describe the electrical behavior of a battery helps the designer to better predict and optimize the battery runtime and circuit performance. In this project a suggested electrical circuit model is used to evaluate the battery characteristics of an alkaline cell and a rechargeable NiMH cell and the same is implemented in Cadence environment. The measured data is compared with the simulated data and the results are discussed further. This circuit model is efficient in modeling the behavior of the batteries used in this project and can be extended to various other types of batteries.


SCOTT LOLLMAN

A Novel Approach for Visualizing Data Sets With Many Attributes

When & Where:


2001B Eaton Hall

Committee Members:

Jim Miller, Chair
Arvin Agah
Frank Brown


Abstract

This paper proposes a novel extension to the Attribute Blocks visualization technique that can be applied to visualizations containing many attributes. The Attribute Blocks visualization scheme is a technique that divides the visualization space into a regular pattern of small cells where each cell displays only one attribute. This paper recommends that the goal of a pattern design should be to have each attribute share equal length edges with each other attribute. This goal imposes new constraints on the number of attributes that can be simultaneously displayed, hence one significant challenge was to develop a new strategy that would allow more flexible pattern geometry and evaluating the effectiveness of this strategy with real data sets.


MOHAMMADREZA HAJIARBABI

A Face Detection and Recognition System For Color Images

When & Where:


2001B Eaton Hall

Committee Members:

Arvin Agah, Chair
Jerzy Grzymala-Busse
Prasad Kulkarni
Bo Luo
Sara Wilson

Abstract

A face detection and recognition system is a biometric identification mechanism which compared to other methods such as finger print identification, speech, signature, hand written and iris recognition is shown to be more important both theoretically and practically. In principle, the biometric identification methods use a wide range of techniques such as machine learning, machine vision, image processing, pattern recognition and neural networks. The methods have various applications such as in photo and film processing, control access networks, etc. In recent years, the automatic recognition of a human face has become an important problem in pattern recognition. The main reasons are that structural similarity of human faces and great impact of illumination conditions, facial expression and face orientation. Face recognition is considered one of the most challenging problems in pattern recognition. A face recognition system consists of two main components, face detection and recognition. In this dissertation we will design and implement a detection and recognition face system using color images with multiple faces. In color images, the information of skin color is used in order to distinguish between the skin pixels and non-skin pixels, dividing the image into some components. The next step is to decide which of these components belong to human face. After face detection, the faces which were detected in the previous step are to be recognized. Appearance based methods used in this work are one of the most important methods in face recognition due to the robustness of the algorithms to head rotation in the images, noise, low quality images, and other challenges.


ARUNABHA CHOUDHURY

Generalized FLIC: Learning with misclassification for Binary Classifiers

When & Where:


2001B Eaton Hall

Committee Members:

Jerzy Grzymala-Busse, Chair
Swapan Chakrabarti
Bo Luo


Abstract

This work formally introduces a generalized fuzzy logic and interval clustering (FLIC) technique which,when integrated with existing supervised learning algorithms, improves their performance. FLIC is a method that was first integrated with neural network in order to improve neural network’s performance in drug discovery using high throughput screening (HTS). This research strictly focuses on binary classification problems and generalizes the FLIC in order to incorporate it with other machine learning algorithms. In most binary classification problems, the class boundary is not linear. This pose a major problem when the number of outliers are significantly high, degrading the performance of the supervised learning function. FLIC identifies these misclassifications before the training set is introduced to the learning algorithm. This allows the supervised learning algorithm to learn more efficiently since it is now aware of those misclassifications. Although the proposed method performs well with most binary classification problems, it does significantly well for data set with high class asymmetry. The proposed method has been tested on four well known data sets of which three are from UCI Machine Learning repository and one from BigML. Tests have been conducted with three well known supervised learning techniques: Decision Tree, Logistic Regression and Naive Bayes. The results from the experiments show significant improvement in performance. The paper begins with a formal introduction to the core idea this research is based upon. It then discusses a list of other methods that have either inspired this research or have been referred to, in order to formalize the techniques. Subsequent sections discuss the methodology and the algorithm which is followed by results and conclusion. 

Keyword: supervised learning, binary classification, fuzzy logic, clustering 


PRACHI KHADILKAR

TicketWise, an Interface for Integrating an Email Service with a Ticketing Tool

When & Where:


220 Best

Committee Members:

Hossein Saiedian, Chair
Fengjun Li
Bo Luo


Abstract

IT Service Management (ITSM) is an IT function associated with resolving user issues through the support of a service desk. Some of the widely used ticket management tools that service desk utilizes include Remedy, Falcon and ServiceNow. These tools typically use a web portal as a front end for users to submit issues. Alternately, these tools may have a dedicated application that can be installed on a device. However, an application may not be compatible with various devices and is also very costly to maintain compatibility with current technology. Access to web portals requires a high bandwidth internet connection and connectivity could be a challenge in restricted areas. In these cases, a user’s only option is to report an issue via email. Email is supported on most connected devices and has very low internet bandwidth requirement. It also tends to be an ideal solution for traveling professionals. However, none of these ITSM tools provide a convenient mechanism to log tickets via email. Emails have to be manually converted to a ticket by the service desk. This process has a potential for human errors. 

With this objective, we have implemented an auto ticketing tool, 'TicketWise' that will automatically convert email requests into service tickets. This tool provides the necessary technological bridge for interfacing an email service with a ticketing system. This is a new feature that can be integrated with existing ITSM tools. New tickets get created for users who are registered with the system. Non-registered emails are automatically filtered out. Upon receiving a confirmation email the user can also send a follow up email. This information also gets updated in the ticket work log. 

TicketWise has been integrated with an application, 'TicketMe' that simulates a ticketing system. Validation has been successfully conducted by sending emails from a registered and a non-registered email address. In the former case, a new ticket was successfully created. In the latter, the email was filtered out. Contents from a follow up email for the ticket confirmation were also successfully added to the ticket work log. The results of the validation were satisfactory.