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

Luke Staudacher

Enabling Versal-Based Signal Processing Through a Development Framework and User Guide

When & Where:


Nichols Hall, Room 246 (Executive Conference Room)

Committee Members:

Jonathan Owen, Chair
Shannon Blunt
Carl Leuschen
Erik Perrins

Abstract

AMD’s latest generation of adaptive system-on-chip (SoC) devices, the Versal product family, offers enhanced processing capabilities that are attractive to researchers and system designers. However, these capabilities introduce a significant knowledge barrier, limiting the practical benefits of Versal devices compared to more mature platforms from AMD, Intel, and other industry vendors. This project addresses this challenge through two primary deliverables: a software framework and a comprehensive user manual targeting Versal development. The software framework, named RSL Versal Core, provides a framework for users unfamiliar with Versal devices by selectively abstracting away more complex design components. Using a small set of commands, users can synthesize a programmable logic (PL) design, compile a Linux operating system for the onboard Arm processor with PL communication support, and program supported development boards. Following initial setup, the framework also supports extended software and firmware development for specific project needs. The accompanying user manual documents both RSL Versal Core and broader Versal development concepts. It guides users through reproducing and customizing the framework outputs manually and introduces key architectural and design principles useful for effective Versal-based system development. Together, these deliverables enable new developers to rapidly gain proficiency with Versal platforms and enable implementation of digital signal processing (DSP) concepts.


William Powers

Implementation and Analysis of Robust System-Informed Waveform Design

When & Where:


Nichols Hall, Room 246 (Executive Conference Room)

Committee Members:

Jonathan Owen, Chair
Shannon Blunt
Carl Leuschen


Abstract

Due to rapid advances in high-speed analog-to-digital conversion and software-defined architectures, modern radar systems increasingly shift signal generation and conditioning into the digital domain. These architectures enable high-fidelity signal capture and provide substantial flexibility in waveform synthesis and signal processing that was previously impractical in analog implementations. Despite these advances, however, achievable radar performance remains fundamentally constrained by the physical transmit hardware through which the signal is ultimately realized. Nonlinear amplification, finite bandwidth, and memory effects introduce distortion that creates a significant gap between idealized waveform design and the waveform that is physically radiated.

To address this limitation, this work proposes a system-aware radar waveform design framework that couples data-driven system identification with deterministic optimization to generate waveforms tailored to the underlying transmit hardware. A complex baseband memory polynomial model is developed to characterize nonlinear transmit-chain behavior using loopback measurements, where $\ell_1$-regularized LASSO estimation is employed to improve robustness against ill-conditioning and feature redundancy. Under this architecture, a generalized integrated sidelobe level (GISL) objective is reformulated using logarithmic scalarization to produce a numerically stable and Pareto-tunable optimization criterion capable of balancing output energy and sidelobe suppression. Additionally, efficient vectorized gradient expressions are derived using Wirtinger calculus and implemented using gradient-based descent and the limited-memory BFGS algorithm for practical high-dimensional waveform synthesis.

To validate the framework, a comprehensive hardware-in-the-loop testbench was developed supporting direct model identification and experimental evaluation of optimized waveform performance. Simulation and experimental results demonstrate that continuous-phase FM waveforms exhibit strong inherent robustness to nonlinear distortion, while phase-coded waveforms with large instantaneous phase discontinuities show significantly greater sensitivity to transmit-chain impairments. Across both waveform classes, the proposed framework achieves substantial improvements in output power efficiency and pulse compression performance relative to system-agnostic waveform design. These results demonstrate that transmitter constraints must be treated as fundamental design variables rather than secondary effects and establish system-aware optimization as a practical framework for next-generation radar waveform synthesis.


Cody Gish

Real-time GPU Based Arbitrary Waveform Generation Utilizing a Software-Defined Radar Platform

When & Where:


Nichols Hall, Room 246 (Executive Conference Room)

Committee Members:

Jonathan Owen, Chair
Shannon Blunt
Patrick McCormick


Abstract

Due to the ever-growing demand for access to the finite resources of the electromagnetic spectrum, significant effort has been directed toward improving spectrum utilization. This has become a particular challenge in radar transmission design, where waveform diversity techniques have emerged as a promising solution despite the accompanying implementation complexity. Diverse signals are inherently non-repeating and pose unique challenges in comparison to traditional radar waveforms. Software defined radios (SDRs) allow for traditional RF components and signal processing to be implemented and controlled in software rather than hardware, providing a platform for testing experimental radar algorithms. This thesis presents a real-time parallel implementation of five previously developed distinct waveform-diverse radar signals for use in a coherent SDR system. The implemented waveforms include stochastic waveform generation (StoWGe), multi-user radar communication (MURC), phase-attached radar communication (PARC), pseudo-random optimized frequency modulation (PRO-FM), and waveform recycling. To enable real-time generation at maximum SDR data rates, these waveforms are implemented using digital synthesis techniques via GPU parallel processing. This approach alleviates CPU resource limitations by offloading computationally intensive waveform generation tasks to the GPU, enabling continuous high-throughput operation. A custom asynchronous transmit and receive architecture is developed to integrate these GPU-accelerated waveforms with UHD-based SDR hardware. The system leverages a multithreaded framework approach that can sustain coherent and synchronized radar operation. To validate the system, a series of loopback testing across all waveforms and a variety of parameters is completed to confirm the execution of the generate-transmit-receive chain.


David Felton

Optimization and Evaluation of Physical Complementary Radar Waveforms

When & Where:


Nichols Hall, Room 129 (Apollo Auditorium)

Committee Members:

Shannon Blunt, Chair
Rachel Jarvis
Patrick McCormick
James Stiles
Zsolt Talata

Abstract

The RF spectrum is a precious, finite resource with ever-increasing demand. Consequently, the mandate to be a "good spectral neighbor" is in direct conflict with the requirements for high-performance sensing where correlation error is fundamentally limited. As such, matched-filter radar performance is often sidelobe-limited with estimation error being constrained by the time-bandwidth (TB) of the collective emission. The methods developed here seek to bridge this gap between idealized radar performance and practical utility via waveform design.    

Estimation error becomes more complex when employing pulse-agility. In doing so, range-sidelobe modulation (RSM) spreads energy across Doppler, rendering traditional methods ineffective. To address this, the gradient-based complementary-FM framework was developed to produce complementary sidelobe cancellation (CSC) after coherently combining subsets within a pulse-agile emission. In contrast to the majority of complementary signals, explored via phase-coding, these Comp-FM waveform subsets achieve CSC while preserving hardware-compatibility since they are FM (though design distortion is never completely avoided). Although Comp-FM addressed practicality via hardware amenability, CSC was localized to zero-Doppler. This work expands the Comp-FM notion to a Doppler-generalized (DG) framework, extending the cancellation condition to an arbitrary span. The same framework can likewise be employed to jointly optimize an entire coherent processing interval (CPI) to minimize RSM within the radar point-spread-function (PSF), thereby generalizing the notion of complementarity and introducing the potential for cognitive operation if sufficient scattering knowledge is available a-priori.          

Sensing with a single emitter is limited by self-inflicted error alone (e.g., clutter, sidelobes), while MIMO systems must additionally contend with the cross-responses from emitters operating concurrently (e.g., simultaneously, spatially proximate, in a shared spectrum), further degrading radar sensitivity. Now, total correlation error is dictated by the overlapping TB (i.e., how coincident are the signals) and number of operating emitters, compounding difficulty to estimate if left unaddressed. As such, the determination of "orthogonal waveforms" comprises a large portion of MIMO literature, though remains a phenomenological misnomer for pulsed emissions. Here, the notion of complementary-FM is applied to a multi-emitter context in which transmitter-amenable quasi-orthogonal subsets, occupying the same spectral band, are produced via a similar gradient-based approach. To further practicalize these MIMO-Comp-FM waveform subsets, the same "DG" approach described above, addressing the otherwise-default Doppler-induced degradation of complementary signals, is applied. In doing so, Doppler-independent separability and complementarity greatly improves estimation sensitivity for multi-emitter systems. 

This MIMO-Comp-FM framework is developed for standard matched filter processing. Coupling this framework with a "DG" form of the previously explored MIMO-MiCRFt is also investigated, illustrating the added benefit of pairing optimized subsets with similarly calibrated processing. 

Each of these methods is developed to address unique and increasingly complex sources of estimation error. All approaches are initially developed and evaluated via simulated analysis where ground-truth is known. Then, despite hardware-induced distortion being unavoidable, the MIMO-Comp-FM framework is confirmed via loopback measurements to preserve the majority of CSC that was observed in simulation. Finally, open-air demonstration of each approach validates practical utility on a radar system.


Past Defense Notices

Dates

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. 


SANTOSH GONDI

Design, Implementation, and Performance Analysis of In-Home Video based Monitoring System for Patients with Dementia

When & Where:


246 Nichols Hall

Committee Members:

James Sterbenz, Chair
Victor Frost
Bo Luo
Russ Waitman

Abstract

Dementia is a major public health problem affecting 35 million people in USA. The caregivers of dementia patients experience many types of physical and psychological stress while dealing with disruptive behaviors of dementia patients. This will also result in frequent hospitalizations and re-admissions. In this project we design, implement, and measure the performance of an advanced video based monitoring system to aide the caregivers in managing the behavioral symptoms of dementia patients. The caregivers will be able to easily capture and share the antecedents, consequences, and the function of behavior, through a video clip, and get the real-time feedback from clinical experts. Overall the system will help in reducing the hospital admission/readmission, improve the quality of life for caregivers, and in general result in reduced cost of health care systems. System is developed using python scripts, open source web frameworks, FFmpeg tool chain, and commercial off-the-shelf IP camera and mini-PC. WebRTC is used for video based coaching of caregivers. A framework has been developed to evaluate the storage and retrieval latency of video clips to public and On-premise clouds, video streaming performance in LAN and WLAN environments, and WebRTC performance in different types of access networks. InstaGENIrack, a GENI rack in KU is used as on-premise cloud infrastructure for the evaluation. OpenSSL utilities are employed for secured transport and storage of captured video clips. We conducted the trials in Google fiber ISP in Kansas city, and compared the performance with other traditional ISPs..


ANSU JOYS

Identifying Software Phase Markers in Java Byte Code

When & Where:


250 Nichols Hall

Committee Members:

Prasad Kulkarni, Chair
Andy Gill
Bo Luo


Abstract

Program execution can be classified into phases. These phases can be repeated during a single execution of the application. Ability to identify and classify the phases statically will help prepare the system early for the next phase, which can benefit overall program performance at run time. While static program phase detection algorithms have been explored for binary executable with promising results, to the best of our knowledge, such algorithms have not been targeted and evaluated for managed language, specifically Java, programs. Accurate detection of future program phases can allow the Java virtual machine to perform phase-specific optimizations to improve performance. 

In this project, we build a framework to detect program phases and insert software phase markers in Java byte code. We employ an existing algorithm to detect program phases and adapt it to detect phases for Java binaries. We modify the control flow graph generated by the byte code analysis tool WALA (Watson library for Analysis) to integrate program loops. We analyze each method in the control flow graph produced by WALA to detect loops, and convert the call graph into a "call loop graph". We then rely on program profiling to provide data on the number of times each basic block and edge is reached at run-time. We use this profiling information to determine the average number of instructions executed along each graph edge, the average number of times an edge is executed and the standard deviation for instructions on these edges in our algorithm to identify the software phase markers. 


ADITYA BALASUBRAMANIAN

Study and Performance Analysis of OFDM using GNURadio and USRP

When & Where:


250 Nichols Hall

Committee Members:

Lingjia Liu, Chair
Joe Evans
James Sterbenz


Abstract

Software defined radios (SDR) are a rapidly evolving technology which are used widely in industry and academia today. They offer a very low cost and flexible alternative for implementing and testing wireless technologies since most of the physical layer functionalities are implemented in 
software instead of hardware. Universal Software Defined Radio Peripheral (USRP) is one of the most popular products belong to the family of SDR. GNURadio, a software development kit comprising of C++ and Python libraries is widely used with USRP as a hardware platform to create SDR applications. 
In this project a tested is implemented for performance analysis of an OFDM communication system using GNURadio and USRP. The performance is analyzed and studied in a practical laboratory environment using GNURadio and USRP. The packet error rate versus SNR is calculated in different 
environmental settings .The effect of Interference and obstruction is also taken into account in studying the performance.


LOGAN SMITH

Validation of CReSIS Synthetic Aperture Radar Processor and Optimal Processing Parameters

When & Where:


317 Nichols Hall

Committee Members:

John Paden, Chair
Chris Allen
Carl Leuschen


Abstract

Sounding the ice sheets of Greenland and Antarctica is a vital component in determining the affect of global warming on sea level rise. Of particular importance to measure are the outlet glaciers that transport ice from the interior to the edge of the ice sheet. These outlet glaciers are difficult to sound due to crevassing caused by the relatively fast movement of the ice in the glacial channel and higher signal attenuation caused by warmer ice. The Center for Remote Sensing of Ice Sheets (CReSIS) uses multi-channel airborne radars with methods for achieving better resolution and signal-to-noise ratio (SNR) in the three major dimension to sound outlet glaciers. Synthetic aperture radar (SAR) techniques are used in the along-track dimension, pulse compression in the range dimension, and an antenna array in the cross-track dimension. 

CReSIS has developed a SAR processor to effectively and efficiently process the data collected by these radars in each dimension. To validate the performance of this processor a SAR simulator was developed with the functionality to test multiple aspects of the SAR processor. In addition to the implementation of this simulator for validation of processing the data in the along-track, cross-track and range dimensions, there are a number of data-dependent processing steps that can affect the quality of the final data product. These include creating matched filters for each dimension of the data, removing phase and amplitude differences between receive channels, and determining the optimal along-track beamwidth to use for processing the data. All of these factors can improve the ability to obtain the maximum amount of information from the collected data. The validation and optimal processing parameters and their theory are discussed here. 


H. SHANKER RAO

Dominant Attribute and Multiple Scanning Approaches for Discretization of Numerical Attributes

When & Where:


2001B Eaton Hall

Committee Members:

Jerzy Grzymala-Busse, Chair
Perry Alexander
Doina Caragea


Abstract

Rapid development of high throughput technologies and database management systems has made it possible to produce and store large amount of data. However, making sense of big data and discovering knowledge from it is a compounding challenge. Generally, data mining techniques search for information in datasets and express gained knowledge in the form of trends, regularities, patterns or rules. Rules are frequently identified automatically by a technique called rule induction, which is the most important technique in data mining and machine learning and it was developed primarily to handle symbolic data. However, real life data often contain numerical attributes and therefore, in order to fully utilize the power of rule induction techniques, an essential preprocessing step of converting numeric data into symbolic data called discretization is employed in data mining. 
Here we present two entropy based discretization techniques known as dominant attribute approach and multiple scanning approach, respectively. These approaches were implemented as two explicit algorithms in a JAVA programming language and experiments were conducted by applying each algorithm separately on seventeen well known numerical data sets. The resulting discretized data sets were used for rule induction by LEM2 or Learning from Examples Module 2 algorithm. For each dataset in multiple scanning approach, experiments were repeated with incremental scans until interval counts were stabilized. Preliminary results from this study indicated that multiple scanning approach performed better than dominant attribute approach in terms of producing comparatively smaller and simpler rule sets. 


YI ZHU

Matrix and Tensor-based ESPRIT Algorithm for Joint Angle and Delay Estimation in 2D Active Massive MIMO Systems and Analysis of Direction of Arrival Estimation Algorithms for Basal Ice Sheet Tomography

When & Where:


246 Nichols Hall

Committee Members:

Lingjia Liu, Chair
Shannon Blunt
John Paden
Erik Perrins

Abstract

In this thesis, we apply and analyze three direction of arrival (DoA) algorithms to tackle two distinct problems: one belongs to wireless communication, the other to radar signal processing. Though the essence of these two problems is DoA estimation, their formulation, underlying assumptions, application scenario, etc. are totally different. Hence, we write them separately, with ESPRIT algorithm the focus of Part I and MUSIC and MLE detailed in Part II. 

For wireless communication scenario, mobile data traffic is expected to have an exponential growth in the future. In “massive MIMO” systems, a base station will rely on the uplink sounding signals from mobile stations to figure out the spatial information to perform MIMO beamforming. Accordingly, multi-dimensional parameter estimation of a ray-based multipath wireless channel becomes crucial for such systems to realize the predicted capacity gains. We study joint angle and delay estimation for such system and results suggest that the dimension of the antenna array at the base station plays an important role in determining the estimation performance. These insights will be useful for designing practical “massive MIMO” systems in future mobile wireless communications. 

For the problem of radar sensing of ice sheet topography, one of the key requirements for deriving more realistic ice sheet models is to obtain a good set of basal measurements that enables accurate estimation of bed roughness and conditions. For this purpose, 3D tomography of the ice bed has been successfully implemented with the help of DoA. The SAR focused datasets provide a good case study. For the antenna array geometry and sample support used in our tomographic application, MUSIC performs better originally using a cross-over analysis where the estimated topography from crossing flight lines are compared for consistency. However, after several improvements applied to MLE, MLE outperforms MUSIC. We observe that, the spatial bottom smoothing, aiming to remove the artifacts made by MLE algorithm, is the most essential step in the post-processing procedure. The 3D tomography we obtained lays a good foundation for further analysis and modeling of ice sheets. 


YUHAO YANG

Protecting Attributes and Contents in Online Social Networks

When & Where:


250 Nichols Hall

Committee Members:

Bo Luo, Chair
Arvin Agah
Luke Huan
Prasad Kulkarni
Alfred Ho

Abstract

With the fast development of computer and information technologies, online social networks grow dramatically. While huge amount of information is distributed expeditiously in online social networking sites, privacy concerns arise. 
In this dissertation, we first study the vulnerabilities of user attributes and contents, in particular, the identifiability of the users when the adversary learns a small piece of information about the target. We further employ an information theory based approach to quantitatively evaluate the threats of attribute-based re-identification. We have shown that large portions of users with online presence are highly identifiable. 
The notion of privacy as control and information boundary has been introduced by the user-oriented privacy research community, and partly adopted in commercial social networking platforms. However, such functions are not widely accepted by the users, mainly because it is tedious and labor-intensive to manually assign friends into such circles. To tackle this problem, we introduce a social circle discovery approach using multi-view clustering. We present our observations on the key features of social circles, including friendship links, content similarity and social interactions. We treat each feature as one view, and propose a one-side co-trained spectral clustering technique, which is tailored for the sparse nature of our data. We evaluate our approach on real-world online social network data, and show that the proposed approach significantly outperforms structure-based clustering. Finally, we build a proof-of-concept demonstration of the automatic circle detection and recommendation approaches.


JAMUNA GOPAL

I Know Your Family: An Hybrid Information Retrieval Approach to Extract Family Information

When & Where:


250 Nichols Hall

Committee Members:

Bo Luo, Chair
Jerzy Grzymala-Busse
Prasad Kulkarni


Abstract

The aim of this project is to identify the family related information of a person from their Twitter Data. We use their personal details, tweets and their friends’ details in order to achieve this. Since, we deal with the modern world short text data; we have used a hybrid information retrieval methodology taking into account the Parts of Speech of the data, Phrase Similarity and the Semantic Similarity of the data along with the openly available twitter data. The future use of this research is to develop a Client Side protection tool that will help users validate the data to be posted for privacy breech.


KAIGE YAN

Power and Performance Co-optimization for Emerging Mobile Platforms

When & Where:


250 Nichols Hall

Committee Members:

Xin Fu, Chair
Prasad Kulkarni
Heechul Yun


Abstract

The mobile devices emerge as the most popular computing platform since 2011. Different from the traditional PC, the mobile devices are more power-constraint and performance-sensitive due to its size. In order to reduce the power consumption and improve the performance, we focus on the Last Level Cache (LLC), which is the power-hungry structure and critical to the performance in mobile platforms. In this project, we first integrate the McPAT power model into the Gem5 simulator. We also introduce the emerging memory technologies, such as Sprin-Transfer Torque RAM (STT-RAM) and embedded DRAM (eDRAM), into the cache design and compare their power and performance effectiveness with the conventional SRAM-based cache. Additionally, we identify that the frequent execution switch between the kernel and user code is the major reason for the high LLC miss in mobile applications. This is because blocks belonging to kernel and user space have severe interferences. We further propose static and dynamic way partition schemes to separate the cache blocks from kernel and user space. The experiment results show promising power reduction and performance improvement with our proposed techniques.