Engineering Commons^™

Greentpu: Predictive Design Paradigm For Improving Timing Error Resilience Of A Near-Threshold Tensor Processing Unit, Pramesh Pandey, Prabal Basu, Koushik Chakraborty, Sanghamitra Roy

Electrical and Computer Engineering Faculty Publications

The emergence of hardware accelerators has brought about several orders of magnitude improvement in the speed of the deep neural-network (DNN) inference. Among such DNN accelerators, the Google tensor processing unit (TPU) has transpired to be the best-in-class, offering more than 15\times speedup over the contemporary GPUs. However, the rapid growth in several DNN workloads conspires to escalate the energy consumptions of the TPU-based data-centers. In order to restrict the energy consumption of TPUs, we propose GreenTPU - a low-power near-threshold (NTC) TPU design paradigm. To ensure a high inference accuracy at a low-voltage operation, GreenTPU identifies the patterns in …

Noisy Importance Sampling Actor-Critic: An Off-Policy Actor-Critic With Experience Replay, Miriam A M Capretz, Norman Tasfi

Electrical and Computer Engineering Publications

This paper presents Noisy Importance Sampling Actor-Critic (NISAC), a set of empirically validated modifications to the advantage actor-critic algorithm (A2C), allowing off-policy reinforcement learning and increased performance. NISAC uses additive action space noise, aggressive truncation of importance sample weights, and large batch sizes. We see that additive noise drastically changes how off-sample experience is weighted for policy updates. The modified algorithm achieves an increase in convergence speed and sample efficiency compared to both the on-policy actor-critic A2C and the importance weighted off-policy actor-critic algorithm. In comparison to state-of-the-art (SOTA) methods, such as actor-critic with experience replay (ACER), NISAC nears the …

What Difference Does A Catalyst Make?, Tammy Guthrie, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use different catalysts for the decomposition of Hydrogen Peroxide, to determine if different catalysts affect the energy that is generated during the reaction.

Examining The Effects Of Reducing The Cement Content Of Portland Cement Concrete Pavement, Bryan Casillas

Graduate Theses and Dissertations

Portland cement is a significant component in a concrete mixture. For concrete used in portland cement concrete pavement (PCCP), the Arkansas Department of Transportation (ARDOT) specifies a minimum cementitious material content of 564 lb/yd3 and a maximum water-cementitious material ratio of 0.45. Prior research conducted at the University of Arkansas, TRC 0603, indicated concrete mixtures used in five bridge decks throughout Arkansas achieved the required 28-day strength at seven days, and the measured compressive strength at 28 days was 30% greater than required. The use of high strength concrete in pavements throughout the state can increase cracking and consequently reduce …

Quantifying Workability, Compactability, And Cohesion Gain Of Asphalt Emulsion Cold In-Place Recycling, Sadie Casillas

Graduate Theses and Dissertations

To maximize the life and quality of a pavement, proper maintenance and rehabilitation are essential. Strategies for pavement rehabilitation with many sustainable benefits are pavement recycling. This dissertation focuses on two types of in-situ pavement recycling: Cold in-place recycling (CIR) stabilized with asphalt emulsion and full depth reclamation (FDR) stabilized with asphalt emulsion or foamed asphalt. One white paper (Chapter 2), two accepted peer reviewed journal articles (Chapters 3 and 4), and one submitted peer reviewed journal article (Chapter 5) are presented in this document to create better understanding of the unique material characterization of asphalt emulsion cold recycled materials, …

Verifying The Calcium Oxychloride Threshold In Cementitious Pastes, Fatoumata Traore

Graduate Theses and Dissertations

Calcium oxychloride (CAOXY) formation is a serious deterioration mechanism known to cause joint damage in concrete pavements. CAOXY is the product of a chemical reaction between calcium chloride (CaCl2) or magnesium chloride (MgCl) deicing salts and calcium hydroxide in the cementitious matrix. Currently, the accepted CAOXY threshold at which deterioration is mitigated in cementitious paste is 15 g/100 g paste (15 oz/100 oz paste); however, this limit was developed using flexural strength testing. For this investigation, the current threshold was evaluated using compressive strength and mass change over time in paste specimens exposed to CaCl2. Fly ash is used to …

Commodity-Based Freight Activity On Inland Waterways Through The Fusion Of Public Datasets For Multimodal Transportation Planning, Magdalena I. Asborno

Graduate Theses and Dissertations

Within the U.S., the 18.6 billion tons of goods currently moved along the multimodal transportation system are expected to grow 51% by 2045. Most of those goods are transported by roadways. However, several benefits can be realized by shippers and consumers by shifting freight to more efficient modes, such as inland waterways, or adopting a multimodal scheme. To support such freight growth sustainably and efficiently, federal legislation calls for the development of plans, methods, and tools to identify and prioritize future multimodal transportation infrastructure needs. However, given the historical mode-specific approach to freight data collection, analysis, and modeling, challenges remain …

Severe Weather In Nebraska: Impacts On Nonmetropolitan Nebraskans. 2020 Nebraska Rural Poll Results, Rebecca J. Vogt, Cheryl Burkhart-Kriesel, Bradley Lubben, L. J. Mcelravy, Timothy Meyer, Steve Schulz, Jason L. Weigle

Rural Futures Institute: Publications

In March 2019, a bomb cyclone produced a historic blizzard as well as flooding that impacted many counties in Nebraska. Given that, did rural Nebraskans experience extreme weather events or natural disasters in 2019? To what extent were they harmed by these weather events? What personal impacts did they experience? How concerned are they about weather events? This paper provides a detailed analysis of these questions. This report details 1,979 responses to the 2020 Nebraska Rural Poll, the 25th annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about weather events. Comparisons are made among …

A Novel Tri-Band Reconfigurable Microstrip Patch Antenna, Wen Tao Li, Meng Wei, Bahareh Badamchi, Harish Subbaraman, Xiaowei Shi

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, a novel tri-band reconfigurable patch antenna with simple structure is presented. By changing the on-off state of only two PIN diodes, the antenna can operate in three bands, namely X-band, Ku-band, and Ka-band. The overall size of the antenna is 0.24λ_L × 0.5λ_L × 0.019λ_L, where λ_L is the free-space wavelength of the lowest operating frequency. A prototype is fabricated and measured to verify the design. The measurement results are in good agreement with the simulation results, which indicate that the proposed antenna can be flexibly switched between three …

Continuous Learning In A Single-Incremental-Task Scenario With Spike Features, Ruthvik Vaila, John Chiasson, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

Deep Neural Networks (DNNs) have two key deficiencies, their dependence on high precision computing and their inability to perform sequential learning, that is, when a DNN is trained on a first task and the same DNN is trained on the next task it forgets the first task. This phenomenon of forgetting previous tasks is also referred to as catastrophic forgetting. On the other hand a mammalian brain outperforms DNNs in terms of energy efficiency and the ability to learn sequentially without catastrophically forgetting. Here, we use bio-inspired Spike Timing Dependent Plasticity (STDP) in the feature extraction layers of the network …

A Self Controlled Rdp Approach For Feature Extraction In Online Handwriting Recognition Using Deep Learning, Sukhdeep Singh, Vinod Kumar Chauhan, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

The identification of accurate features is the initial task for benchmarked handwriting recognition. For handwriting recognition, the objective of feature computation is to find those characteristics of a handwritten stroke that depict the class of a stroke and make it separable from the rest of the stroke classes. The present study proposes a feature extraction technique for online handwritten strokes based on a self controlled Ramer-Douglas-Peucker (RDP) algorithm. This novel approach prepares a smaller length feature vector for different shaped online handwritten strokes without preprocessing and without any control parameter to RDP. Thus, it also overcomes the shortcomings of the …

Human Behavior Is A Significant Flaw In Maintaining Cyber Security, Elizabeth Jackson

Cybersecurity Undergraduate Research Showcase

Human behavior and data security utilization must be intertwined; in order to mitigate the negative effects of cyber attacks. No consumer wants their data hacked, breached, stolen, shared or wiped out. It is imperative to survey the type of education is needed to keep users safe and interested in securing their data. This can be done by simply seeking out the consumer's view of data security. The information obtained would allow the cybersecurity community to offer a simple way for consumers to protect their mobile data. There is a constant interaction between human behavior and the need for increased data …

Investigation And Mitigation Of Radio Frequency Interference Caused By Weak Grounding Of Usb Type-C Receptacle Connector, Anfeng Huang, Xin Yan, Jingdong Sun, Qiaolei Huang, Jun Fan, Songping Wu, Dave Zhang, Huan Liao, Shuai Jin, Zhiping Yang

Electrical and Computer Engineering Faculty Research & Creative Works

In modern mobile electronic systems, USB connector has been identified as one of the dominant noise sources for desense issues. In this paper, the noise coupled to the Wi-Fi antenna from a USB connector is investigated. With the assistance of full-wave simulations, the root cause of desense noise is identified as the non-ideal electrical connection between the metal chassis and the USB receptacle shell where it is installed. The proposed radiation mechanism is validated through measurements of a real tablet device, and 15 dB noise level reduction is observed with a better grounding structure.

Room Temperature Semiconductor Radiation Detectors Based On Cdznte And Cdzntese, Mohsin Sajjad

Theses and Dissertations

In recent years, there have been considerable interests in nuclear radiation detectors for national security and nuclear safeguard including monitoring special nuclear materials and nuclear waste characterization, for medical imaging devices using nuclear medicine such as positron emission tomography (PET), and for NASA space astronomy. One of the most promising semiconductors being considered for the field-deployable nuclear detector is cadmium zinc telluride (CdZnTe or CZT). CZT is a ternary semiconductor that can efficiently stop and detect high-energy gamma-rays at room temperature. CZT has desirable properties for efficient nuclear radiation detection and imaging due to high atomic number (Z ~ 50, …

Red Blood Cell Dynamics On Non-Uniform Grids Using A Lattice Boltzmann Flux Solver And A Spring-Particle Red Blood Cell Model, Brendan Walsh

Doctoral

The Computational Haemodynamics Research Group (CHRG) in Technological University Dublin is developing a computational fluid dynamics (CFD) software package aimed specifically at physiologically-realistic modelling of blood flow. A physiologically-realistic model of blood flow involves calculating the deformation of individual red blood cells (RBCs) and the contribution of this deformation to the overall blood flow. The CHRG has developed an enhanced spring-particle RBC structural model that is capable of modelling the full stomatocyte-discocyteechinocyte (SDE) transformation. This RBC model, incorporated into a fluid dynamics solver, will provide a physiologically-realistic blood flow model. In this work the overall plasma flow is modelled using …

Audio-Visual Caption Evaluation Metric For People Who Are Deaf And Hard Of Hearing, Akhter Al Amin

Articles

While the availability of captioned television programming has increased, the quality of this captioning is not always acceptable to Deaf and Hard of Hearing (DHH) viewers, especially for live or unscripted content, broadcast from local television stations, especially in smaller markets. There is a need for formal metrics to evaluate captioning quality, to enable audits or quality assurance. Although some current caption metrics focus on comparing the textual accuracy (comparing the caption text and accurate transcription of what was spoken), there are other properties of captions that may affect quality or usability judgments. We propose to conduct experiments with DHH …

Classification Of Plant Moisture Conditions Using Canopy And Leaf Temperature Responses To Step Changes Of Incident Radiation, George Meyer, Ellen T. Paparozzi, Erin Stevens

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Environmental and soil conditions affect plant productivity. Determining and understanding how plants respond to moisture stress may be considered in different ways, but often not easily done. This study focused on measuring canopy and individual leaf temperature response times of selected horticultural and agricultural crops, treated to very dry (moisture stress) and well-watered conditions, and subjected to an incident step radiation change at the top of the canopy, in a controlled environment at a constant air temperature. A light-emitting-diode (LED), grow light system, delivering approximately 400 μEinstein s-1 m-2 of photosynthetically-active-radiation (PAR) was turned on and off to produce light …

Deep Learning For Real-World Object Detection, Xiongwei Wu

Dissertations and Theses Collection (Open Access)

Despite achieving significant progresses, most existing detectors are designed to detect objects in academic contexts but consider little in real-world scenarios. In real-world applications, the scale variance of objects can be significantly higher than objects in academic contexts; In addition, existing methods are designed for achieving localization with relatively low precision, however more precise localization is demanded in real-world scenarios; Existing methods are optimized with huge amount of annotated data, but in certain real-world scenarios, only a few samples are available. In this dissertation, we aim to explore novel techniques to address these research challenges to make object detection algorithms …

New Models For Truck Appointment Problem And Extensions, Mohammad Torkjazi

Theses and Dissertations

The problematic issues surrounding gate congestion at marine container terminals have been well documented. Random truck arrivals at maritime container terminals are one of the primary reasons for gate congestion. Gate congestion negatively affects the terminal’s and drayage firms’ productivity and the surrounding communities in terms of air pollution and noise. To alleviate gate congestion, more and more terminals in the U.S. are utilizing a truck appointment system (TAS).

The first study proposes a novel approach for designing a Truck Appointment System (TAS) intended to serve both the marine container terminal operator and drayage operators. The aim of the proposed …

Synthesis Of Carbide Ceramics Via Reduction And Carburization Of Oxyanions Adsorbed Onto An Activated Carbon Matrix, Grant Wallace

Graduate Theses & Non-Theses

Carbide ceramics rank high among the hardest and most chemically resistant materials. Their ability to resist physical and chemical attack under conditions where more traditional materials fail make them very desirable for a number of industrial applications. Their use is limited, however, due to the expensive and energy-intensive methods required to produce them commercially.

A more versatile and energy-efficient process for commercial carbide production has been developed by synthesizing micron/sub-micron carbide ceramic particles through the adsorption and subsequent carburization of anions on an activated carbon matrix. Oxyanion solutions containing sodium tungstate, sodium molybdate, or sodium metasilicate are adsorbed onto activated …

A Testbed And Methods For Improved Power Plant Model Validation Via Pmu Terminal Measurements, Jacob Eisenbarth

Graduate Theses & Non-Theses

The power industry requires the validation and sharing of the models for generators and controlling equipment to other utilities within North America. Accurate simulation of the electric grid is essential when setting operation and control strategies during various conditions present on the grid. An industry accepted method for performing model validation involves using the voltage and frequency measurements during an event, typically recorded by a phasor measurement unit, to perform a dynamic simulation on the system. The output real and reactive powers from the dynamic simulation and the actual event are then compared to each other. If the real and …

Modeling And Prototyping A Modular, Low-Cost Collision Avoidance System For Uavs, Tyler Holliday

Graduate Theses & Non-Theses

Many challenges arise when attempting to use unmanned aerial vehicles (UAVs) in indoor environments, such as the lack of a GPS signal for use in navigation and the smaller margin of error in movements. Typically, those challenges are addressed by using a collision avoidance system. However, most commercially available collision avoidance systems are expensive, limited in suppliers, and are restricted to use on a specific platform. Additionally, some of the collision avoidance systems choose to forego obstacle detection in one or more directions, usually the upward direction. This work proposes that it is possible to develop a custom, low-cost collision …

Random Packing Material In Disinfection Contactors: Effects On Final Drinking Water Quality, Jessica L. Baker, Susan K. De Long, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the concern about biofilm growth on random packing material (RPM) used to enhance the hydraulic disinfection efficiency of a chlorine contactor. The inflow, outflow, and RPM were monitored for heterotrophic bacteria (via heterotrophic plate counts) and Pseudomonas aeruginosa as indicators of bacteriological water quality and the presence of biofilm. The results of this study show that there was no substantial biofilm growth in a lab-scale chlorine contactor and no substantial increase in bacterial counts for the bulk outflow over a 10-week period. Thus, the potential for excessive biofilm growth should not be considered a barrier concerning the …

Online Survey Of Driver Comprehension Of The Flashing Yellow Arrow For Right-Turn Signal Indications, Sirisha Kothuri, Christopher Monsere, Hisham Jashami, David Hurwitz

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents the results of an online survey of licensed driver comprehension of the right-turn signal displays with a focus on the flashing yellow arrow (FYA) and also including the circular green and red and red arrow. Recruitment postcards were mailed to a random sample of 9,872 residents in Oregon. The online survey yielded 399 responses. The open-ended responses were coded for comprehension and analyzed. The results suggest that FYA for right turns is well understood by Oregon drivers despite its current novelty (only two locations at the time of the research). Importantly, survey respondents were more likely to …

Deep Learning Based Poisson Solver In Particle Simulation Of Pn Junction With Transient Esd Excitation, Ling Zhang, Wenchang Huang, Zeyi Sun, Nicholas Erickson, Ryan From, Jun Fan

Engineering Management and Systems Engineering Faculty Research & Creative Works

In particle simulations of semiconductor devices for electro-static discharge (ESD) study at the microscopic level, solving Poisson's equation is an inevitable but time-consuming step. In this work, a deep learning technique is utilized to resolve Poisson's equation for a PN junction under an ESD event, namely using a trained deep neural network (DNN) to predict the potential distribution according to the charge distribution and the boundary condition under a transient ESD excitation. To improve the generalization performance of the DNN, multiple typical ESD curves with different parameters are used as the excitation boundary to generate large amounts of training data …

Adaptive Interference Mitigation Using Frequency-Selective Limiters Over Gps Band For Automotive Applications, Mahima Shukla, Marina Y. Koledintseva, Michael Geiler, Scott Gillette, Michael Hunnewell, Anton L. Geiler

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we address the challenges associated with the necessity to protect Global Positioning system (GPS) receivers from various types of electromagnetic interference (EMI) generated by internal or external sources. We have developed a compact, lightweight, and passive frequency selective limiter (FSL) technology that automatically and adaptively protects vulnerable input circuits of a GPS receiver from unwanted emissions and prevents a GPS receiver from going into saturation. This technology is based on using magnetostatic surface waves in a magnetically biased ferrite film. The nonlinear processes in ferrite films enable discrimination of signals based on their power levels. In these …

Predicting The Conducted Emission Of A Crm Pfc Below 1mhz By Transient Modeling, Hongseok Kim, Jiayi He, Chunyu Wu, Nicholas Erickson, Sangho Cho, Dohyung Kim, Yeong Hur, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Power Factor Corrections (PFC) are widely used in ac to dc power supplies. Modeling the PFC circuits and predicting the conducted emission (CE) are important in power supply designs. This paper introduces a transient model of a critical conduction mode (CRM) power factor correction. The control circuit of the PFC is built to achieve a CRM working condition with a constant on-time switching. The simulated time domain noise waveform is converted to the conducted EMI in frequency domain via short-time fast Fourier transform (STFFT). The simulated conducted EMI is compared to measured results below 1MHz.

Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to additively manufacture functional alumina ceramics has the potential to lower manufacturing costs and development time for complex components. In this study, the doping effects of zirconia on laser direct deposited alumina ceramics were investigated. The microstructure of the printed samples was analyzed in terms of grain size and composition distribution. The addition of zirconia was found to accumulate along alumina grain boundaries and resulted in significant grain refinement. The zirconia doping largely reduced crack formation during processing compared to that of pure alumina samples. In the case of 10 wt% zirconia, cracking during deposition was nearly completely …

Secondary Uses Of Ballutes After Aerocapture, Josiah Shelton

Master's Theses

Aerocapture is a method for spacecraft orbital insertion that is currently being assessed for use in interplanetary missions. This method would use a low periapsis hyperbolic entry orbit to induce drag allowing the spacecraft to slow down without the use of a propulsion system. This is accomplished by using a ballute (balloon parachute), which is released after the appropriate change in velocity necessary to achieve the desired planetary orbit. Once released, the ballute could deploy a secondary mission vehicle. A MATLAB simulation was run to understand the environment a secondary payload would undergo, such as heating and deceleration, as well …

A Comparison Of Half And Quarter Space Penetration Into Granular Media, Ivan L. Guzman, Magued Iskander, Stephan Bless

Publications and Research

In this study, two experimental techniques are compared for the purpose of visualizing projectile penetration at speeds ranging between 60 and 150 m/s into granular media. The two techniques are half space penetration into a transparent synthetic soil surrogate and quarter space penetration of an opaque natural sand and transparent soil surrogate against an observation window. In both techniques a pneumatic projectile accelerator was employed to launch the projectiles, and high-speed imagery was employed to visualize the penetration events unintrusively. Transparency in transparent targets was achieved by saturating angular fused quartz with a refractive index matched pore fluid made of …