Computer Engineering Commons^™

Cyber-Physical Embedded Systems With Transient Supervisory Command And Control: A Framework For Validating Safety Response In Automated Collision Avoidance Systems, Daniel K. Trembley

Graduate Dissertations and Theses

The ability to design and engineer complex and dynamical Cyber-Physical Systems (CPS) requires a systematic view that requires a definition of level of automation intent for the system. Since CPS covers a diverse range of systemized implementations of smart and intelligent technologies networked within a system of systems (SoS), the terms “smart” and “intelligent” is frequently used in describing systems that perform complex operations with a reduced need of a human-agent. The difference between this research and most papers in publication on CPS is that most other research focuses on the performance of the CPS rather than on the correctness …

Power Efficient High Temperature Asynchronous Microcontroller Design, Nathan William Kuhns

Graduate Theses and Dissertations

There is an increasing demand for dependable and efficient digital circuitry capable of operating in high temperature environments. Extreme temperatures have adverse effects on traditional silicon synchronous systems because of the changes in delay and setup and hold times caused by the variances in each device’s threshold voltage. This dissertation focuses on the design of the major functionality of an asynchronous 8051 microcontroller in Raytheon’s high temperature Silicon Carbide process, rated for operation over 300ºC. The microcontroller is designed in NULL Convention Logic, for which the traditional bus architecture used for data transfer would consume a large amount of power. …

A Hybrid Partially Reconfigurable Overlay Supporting Just-In-Time Assembly Of Custom Accelerators On Fpgas, Zeyad Tariq Aklah

Graduate Theses and Dissertations

The state of the art in design and development flows for FPGAs are not sufficiently mature to allow programmers to implement their applications through traditional software development flows. The stipulation of synthesis as well as the requirement of background knowledge on the FPGAs' low-level physical hardware structure are major challenges that prevent programmers from using FPGAs. The reconfigurable computing community is seeking solutions to raise the level of design abstraction at which programmers must operate, and move the synthesis process out of the programmers' path through the use of overlays. A recent approach, Just-In-Time Assembly (JITA), was proposed that enables …

What Broke Where For Distributed And Parallel Applications — A Whodunit Story, Subrata Mitra

Open Access Dissertations

Detection, diagnosis and mitigation of performance problems in today's large-scale distributed and parallel systems is a difficult task. These large distributed and parallel systems are composed of various complex software and hardware components. When the system experiences some performance or correctness problem, developers struggle to understand the root cause of the problem and fix in a timely manner. In my thesis, I address these three components of the performance problems in computer systems. First, we focus on diagnosing performance problems in large-scale parallel applications running on supercomputers. We developed techniques to localize the performance problem for root-cause analysis. Parallel applications, …

Approximate Computing: An Integrated Cross-Layer Framework, Swagath Venkataramani

Open Access Dissertations

A new design approach, called approximate computing (AxC), leverages the flexibility provided by intrinsic application resilience to realize hardware or software implementations that are more efficient in energy or performance. Approximate computing techniques forsake exact (numerical or Boolean) equivalence in the execution of some of the application’s computations, while ensuring that the output quality is acceptable. While early efforts in approximate computing have demonstrated great potential, they consist of ad hoc techniques applied to a very narrow set of applications, leaving in question the applicability of approximate computing in a broader context.

The primary objective of this thesis is to …

Tangible Interaction As An Aid For Object Navigation In 3d Modeling, Sanmathi Dangeti

Open Access Theses

This study introduced an interaction technique that used tangible interaction for 3D modeling. A hybrid interaction technique using a Kinect camera and a smartphone with a gyroscope was developed for the navigating objects in a 3D modeling software. It was then tested on 20 participants categorized as amateurs who had basic 3D/ CAD modeling experience and 20 participants categorized as the experts who had extensive experience working with the modeling software. This research study presents the need for existence of such interaction technique, gaps from the related previous studies, statistical findings from the current study and possible reasons for the …

Implementing A Wireless Monitoring Solution For A Biomechanical Telemetry System, Hyung Suk Kim

Open Access Theses

Sport-related Traumatic Brain Injury (TBI) is one of the major concerns for collision based sports athletes and their families. The ability to measure impacts on the head is imperative to monitor brain injury and prevent serious TBI. Recent research by the Purdue Neurotrauma Group (PNG) indicates that accumulation of subconcussive impacts may cause permanent neurological damage. Currently available commercial impact monitoring systems are designed as an event-based models which collect impact data above pre-determined acceleration thresholds. To track long-term effects of sub-concussive impacts, event-based modeling is inadequate. The PNG developed a biomechanical sports telemetry system that is capable of storing …

Improvement Of A Biomechanical Telemetry System Hardware Platform, Soon Ho Kwon

Open Access Theses

Traumatic brain injuries (TBI) while playing sports are a major concern for the general public today. Recently, studies have shown that repetitive subconcussive hits can lead to neurological disorders. In order to prevent the athletes from suffering traumatic brain injuries, many organizations related to contact based sports and the military employ commercialized head impact telemetry systems. However, a majority of the commercialized systems is event based which only collects the linear acceleration that exceeds a certain threshold. To accurately record and utilize the data from the impact telemetry system, it is necessary to record all the linear and angular acceleration …

Improving Programmability And Performance For Scientific Applications, Chenyang Liu

Open Access Dissertations

With modern advancements in hardware and software technology scaling towards new limits, our compute machines are reaching new potentials to tackle more challenging problems. While the size and complexity of both the problems and solutions increases, the programming methodologies must remain at a level that can be understood by programmers and scientists alike. In our work, this problem is encountered when developing an optimized framework to best exploit the semantic properties of a finite-element solver. In efforts to address this problem, we explore programming and runtime models which decouple algorithmic complexity, parallelism concerns, and hardware mapping. We build upon these …

Video Annotation By Crowd Workers With Privacy-Preserving Local Disclosure, Apeksha Dipak Kumavat

Open Access Theses

Advancements in computer vision are still not reliable enough for detecting video content including humans and their actions. Microtask crowdsourcing on task markets such as Amazon Mechnical Turk and Upwork can bring humans into the loop. However, engaging crowd workers to annotate non-public video footage risks revealing the identities of people in the video who may have a right to anonymity.

This thesis demonstrates how we can engage untrusted crowd workers to detect behaviors and objects, while robustly concealing the identities of all faces. We developed a web-based system that presents obfuscated videos to crowd workers, and provides them with …

Liquid Metal Particle Popping: Nanoscale To Macroscale, Trevor R. Lear

Open Access Theses

Liquid metal nanoparticles can be used to produce stretchable electronic devices. Understanding the mechanical properties of liquid metal nanoparticles is crucial to optimizing their use in various applications, especially printing of flexible, stretchable electronics. Smaller nanoparticles are desired for high-resolution printing and compatibility with existing scalable manufacturing methods; however, they contain less liquid metal and are more difficult to rupture than larger particles, making them less desirable for post-processing functionality. This study investigates the mechanics of liquid metal particle rupture as a function of particle size. We employ compression of particle films to characterize the composition of the particle core …

Just In Time Assembly (Jita) - A Run Time Interpretation Approach For Achieving Productivity Of Creating Custom Accelerators In Fpgas, Sen Ma

Graduate Theses and Dissertations

The reconfigurable computing community has yet to be successful in allowing programmers to access FPGAs through traditional software development flows. Existing barriers that prevent programmers from using FPGAs include: 1) knowledge of hardware programming models, 2) the need to work within the vendor specific CAD tools and hardware synthesis. This thesis presents a series of published papers that explore different aspects of a new approach being developed to remove the barriers and enable programmers to compile accelerators on next generation reconfigurable manycore architectures. The approach is entitled Just In Time Assembly (JITA) of hardware accelerators. The approach has been defined …

Interactive Logical Analysis Of Planning Domains, Rajesh Kalyanam

Open Access Dissertations

Humans exhibit a significant ability to answer a wide range of questions about previously unencountered planning domains, and leverage this ability to construct “general-purpose'' solution plans for the domain.

The long term vision of this research is to automate this ability, constructing a system that utilizes reasoning to automatically verify claims about a planning domain. The system would use this ability to automatically construct and verify a generalized plan to solve any planning problem in the domain. The goal of this thesis is to start with baseline results from the interactive verification of claims about planning domains and develop the …

Three Dimensional Moving Pictures With A Single Imager And Microfluidic Lens, Chao Liu

Open Access Dissertations

Three-dimensional movie acquisition and corresponding depth data is commonly generated from multiple cameras and multiple views. This technology has high cost and large size which are limitations for medical devices, military surveillance and current consumer products such as small camcorders and cell phone movie cameras. This research result shows that a single imager, equipped with a fast-focus microfluidic lens, produces a highly accurate depth map. On test material, the depth is found to be an average Root Mean Squared Error (RMSE) of 3.543 gray level steps (1.38\%) accuracy compared to ranging data. The depth is inferred using a new Extended …

Exploring Spin-Transfer-Torque Devices And Memristors For Logic And Memory Applications, Zoha Pajouhi

Open Access Dissertations

As scaling CMOS devices is approaching its physical limits, researchers have begun exploring newer devices and architectures to replace CMOS.

Due to their non-volatility and high density, Spin Transfer Torque (STT) devices are among the most prominent candidates for logic and memory applications. In this research, we first considered a new logic style called All Spin Logic (ASL). Despite its advantages, ASL consumes a large amount of static power; thus, several optimizations can be performed to address this issue. We developed a systematic methodology to perform the optimizations to ensure stable operation of ASL.

Second, we investigated reliable design of …

Improving The Resilience Of Cyber-Physical Systems Under Strategic Adversaries, Paul Wood

Open Access Dissertations

Renewable energy resources challenge traditional energy system operations by substituting the stability and predictability of fossil fuel based generation with the unreliability and uncertainty of wind and solar power. Rising demand for green energy drives grid operators to integrate sensors, smart meters, and distributed control to compensate for this uncertainty and improve the operational efficiency of the grid. Real-time negotiations enable producers and consumers to adjust power loads during shortage periods, such as an unexpected outage or weather event, and to adapt to time-varying energy needs. While such systems improve grid performance, practical implementation challenges can derail the operation of …

Algorithms For Lidar Based Traffic Tracking: Development And Demonstration, Vamsi K. Bandaru

Open Access Theses

The current state of the art of traffic tracking is based on the use of video, and requires extensive manual intervention for it to work, including hours of painstaking human examination of videos frame by frame which also make the acquisition of data extremely expensive. Fundamentally, this is because we do not have observability of the actual scene from a camera which captures a 2D projection of the 3D world. Even if video were to be automated, it would involve such algorithms as RANSACK for outlier elimination while matching features across frames or across multiple cameras. This results in algorithms …

Using Ubiquitous Data To Improve Smartwatches' Context Awareness, Yuankun Song

Open Access Theses

Nowadays, more and more data is being generated by various software applications, services and smart devices every second. The data contains abundant information about people’s daily lives. This research explored the possibility of improving smartwatches’ context awareness by using common ubiquitous data. The researcher developed a prototype system consisting of an Android application and a web application, and conducted an experiment where 10 participants performed several tasks with the help of a smartwatch. The result showed a significant improvement of the smartwatch’s context awareness running the prototype application, which used ubiquitous data to automatically execute proper actions according to contexts. …

A Study Of Applications Of 3d Animation For Emergency Medicine Pedagogy, Huilong Zheng

Open Access Theses

There is ample precedent for the use of 3D animation in education, though little research on specific applications in the field of medicine. An experiment was carried out to assess the suitability of 3D animation for educational purposes in emergency medicine courses. Two groups of experimental participants were assessed on their ability to respond to three emergency medical situations in simulated test scenarios. Both groups received equivalent information on how to treat the three different medical emergencies. The control group received the information in traditional lecture format. The experimental group instead received the information from a set of 3D animations. …

Command Shaping With Constrained Peak Input Acceleration To Minimize Residual Vibration In A Flexible-Joint Robot, Yumeng Wu

Open Access Theses

Rapid point-to-point motion is limited when flexibilities exist in the system. In order to minimize the vibrations related to joint flexibilities, much work has been done, including modifying the system so that vibrations can be damped out more quickly, calculating the inverse dynamics of the system and constructing shaped input profiles that avoid system natural frequencies. In this work, the earlier fixed-time command shaping method has been extended to a peak-acceleration-constrained approach with two basis functions, the ramped sinusoid function and the versine function, such that the maximum acceleration is guaranteed without overconstraining the input profiles. The approach is developed …

Analysis Of Feedback Control Applied With Command Shaping To Minimize Residual Vibration, Nicholas L. Jacobs

Open Access Theses

Joint flexibility is a physical trait that affects all robotic systems to some degree. This characteristic has been shown to be very detrimental to the performance of these robotic systems when implementing fast point-to-point motion. During such motion, the robot will induce vibrations in its structure that will extend past the completion of the move. Many techniques have been applied over the years in order to minimize these residual vibrations. One such method is known as command shaping, which will construct the input profile so as to avoid exciting the natural frequencies of the system. This work seeks to extend …

A Holistic Approach To Lowering Latency In Geo-Distributed Web Applications, Shankaranarayanan Puzhavakath Narayanan

Open Access Dissertations

User perceived end-to-end latency of web applications have a huge impact on the revenue for many businesses. The end-to-end latency of web applications is impacted by: (i) User to Application server (front-end) latency which includes downloading and parsing web pages, retrieving further objects requested by javascript executions; and (ii) Application and storage server(back-end) latency which includes retrieving meta-data required for an initial rendering, and subsequent content based on user actions.

Improving the user-perceived performance of web applications is challenging, given their complex operating environments involving user-facing web servers, content distribution network (CDN) servers, multi-tiered application servers, and storage servers. Further, …

Stochastic Modeling And Dem Simulation Of Granular Media Subsidence Due To Underground Activity, Rodrigo Borela Valente

Open Access Theses

Many communities around the world have been established in areas of ongoing, as well as ceased, underground mining activity. Ground movements induced by ore extraction methods and the collapse of abandoned cavities have long been recognized as a hazard to surface structures. A number of approaches have been proposed for the prediction of subsidence in underground mining regions, and their integration to Geographic Information Systems (GIS) can produce a powerful risk management tool. Nevertheless, this application is often limited by either a lack of generality or excessive computational cost of the methods available.

In this work, the stochastic subsidence model …

Monitoring Dbms Activity To Detect Insider Threat Using Query Selectivity, Prajwal B. Hegde

Open Access Theses

The objective of the research presented in this thesis is to evaluate the importance of query selectivity for monitoring DBMS activity and detect insider threat. We propose query selectivity as an additional component to an existing anomaly detection system (ADS). We first look at the advantages of working with this particular ADS. This is followed by a discussion about some existing limitations in the anomaly detection system (ADS) and how it affects its overall performance. We look at what query selectivity is and how it can help improve upon the existing limitations of the ADS. The system is then implemented …

Fast Voxel Line Update For Time-Space Image Reconstruction, Xiao Wang

Open Access Theses

Recent applications of model-based iterative reconstruction(MBIR) algorithm to time-space Computed Tomography (CT) have shown that MBIR can greatly improve image quality by increasing resolution as well as reducing noise and some artifacts. Among the various iterative methods that have been studied for MBIR, iterative coordinate descent(ICD) has been found to have relatively low overall computational requirements due to its fast convergence. However, high computational cost and long reconstruction times remain as a barrier to the use of MBIR in practical applications. This disadvantage is especially prominent in time-space reconstruction because of the large volume of data. This thesis presents a …

Asynchronous Data Processing Platforms For Energy Efficiency, Performance, And Scalability, Liang Men

Graduate Theses and Dissertations

The global technology revolution is changing the integrated circuit industry from the one driven by performance to the one driven by energy, scalability and more-balanced design goals. Without clock-related issues, asynchronous circuits enable further design tradeoffs and in operation adaptive adjustments for energy efficiency. This dissertation work presents the design methodology of the asynchronous circuit using NULL Convention Logic (NCL) and multi-threshold CMOS techniques for energy efficiency and throughput optimization in digital signal processing circuits. Parallel homogeneous and heterogeneous platforms implementing adaptive dynamic voltage scaling (DVS) based on the observation of system fullness and workload prediction are developed for balanced …

Hardware Trojan Detection Via Golden Reference Library Matching, Lucas Weaver

Graduate Theses and Dissertations

Due to the proliferation of hardware Trojans in third party Intellectual Property (IP) designs, the issue of hardware security has risen to the forefront of computer engineering. Because of the miniscule size yet devastating effects of hardware Trojans, few detection methods have been presented that adequately address this problem facing the hardware industry. One such method with the ability to detect hardware Trojans is Structural Checking. This methodology analyzes a soft IP at the register-transfer level to discover malicious inclusions. An extension of this methodology is presented that expands the list of signal functionalities, termed assets, in addition to introducing …

Achieving A Better Balance Between Productivity And Performance On Fpgas Through Heterogeneous Extensible Multiprocessor Systems, Abazar Sadeghian

Graduate Theses and Dissertations

Field Programmable Gate Arrays (FPGAs) were first introduced circa 1980, and they held the promise of delivering performance levels associated with customized circuits, but with productivity levels more closely associated with software development. Achieving both performance and productivity objectives has been a long standing challenge problem for the reconfigurable computing community and remains unsolved today. On one hand, Vendor supplied design flows have tended towards achieving the high levels of performance through gate level customization, but at the cost of very low productivity. On the other hand, FPGA densities are following Moore's law and and can now support complete multiprocessor …

Energy Efficiency In Data Collection Wireless Sensor Networks, Miquel Andres Navarro Patino

Open Access Dissertations

This dissertation studies the problem of energy efficiency in resource constrained and heterogeneous wireless sensor networks (WSNs) for data collection applications in real-world scenarios. The problem is addressed from three different perspectives: network routing, node energy profiles, and network management. First, the energy efficiency in a WSN is formulated as a load balancing problem, where the routing layer can diagnose and exploit the WSN topology redundancy to reduce the data traffic processed in critical nodes, independent of their hardware platform, improving their energy consumption and extending the network lifetime. We propose a new routing strategy that extends traditional cost-based routing …

Representation And Control Of Coordinated-Motion Tasks For Human-Robot Systems, Hyungju Andy Park

Open Access Dissertations

It is challenging for robots to perform various tasks in a human environment. This is because many human-centered tasks require coordination in both hands and may often involve cooperation with another human. Although human-centered tasks require different types of coordinated movements, most of the existing methodologies have focused only on specific types of coordination. This thesis aims at the description and control of coordinated-motion tasks for human-robot systems; i.e., humanoid robots as well as multi-robot and human-robot systems.

First, for bimanually coordinated-motion tasks in dual-manipulator systems, we propose the Extended-Cooperative-Task-Space (ECTS) representation, which extends the existing Cooperative-Task-Space (CTS) representation based …