Electrical and Computer Engineering Commons^™

A Unified Analysis Framework For Tensor Metasurfaces, Bo O. Zhu, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Tensor impedance metasurfaces have attracted much attention recently due to their ability to flexibly manipulate both propagating and surface waves. So far, the analysis of tensor impedance has not been fully supported by commercial electromagnetic simulation software. Also, the representation of formulas of penetrable tensor impedance for both propagating and surface waves is limited in the literature. Hence, a unified analysis framework is proposed for this purpose. It allows the calculation of wave reflection and transmission with arbitrary incident angles, or inversely, the calculation of surface impedance tensors given the desired wave propagation properties. It also allows surface eigenmode analysis, …

The Caching Broadcast Channel With A Wire And Cache Tapping Adversary Of Type Ii, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces the notion of cache-tapping into information theoretic models of coded caching. In particular, the wiretap II model with two receivers equipped with fixed-size cache memories is considered. The adversary chooses a set of symbols from cache placement, delivery, or both to tap into. The legitimate parties know neither whether cache placement, delivery, or both transmissions are tapped, nor the positions of tapped symbols. Only the size of overall tapped set is known. The strong secrecy capacity, i.e., the maximum achievable file rate while keeping the overall library strongly secure, is identified for the instance of two library …

The Caching Broadcast Channel With A Wire And Cache Tapping Adversary Of Type Ii: Multiple Library Files, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

A wiretap model with two receivers equipped with fixed-size cache memories, and a type II adversary is considered. The adversary in this model chooses a subset of symbols to tap into either from cache placement, delivery transmission, or both phases. The legitimate parties do not know the fractions or the positions of the tapped symbols in either phase. For a library of size three files or more, lower and upper bounds on the strong secrecy capacity, i.e., the maximum achievable file rate while keeping the overall library strongly secure, are derived. The strong secrecy capacity is identified for the instance …

Practical Vortex Beam Generation, Nedime Pelin Mohamed Hassan Salem

Dissertations

Vector vortex beams are monochromatic electromagnetic wave fields carrying spin angular momentum (SAM) and orbital angular momentum (OAM). Spin angular momentum is associated with the polarization of the field, whereas OAM yields an azimuthal field dependence of the form exp( jqφ), where φ is the azimuthal angle, and q is an integer designating the helicity order, which is also known as the topological charge of the vortex beam. Vortex beams owe their names to the characteristic on-axis phase singularity and amplitude null.

In this study, a new method to generate vector vortex beams in the microwave regime is devised …

Properties Of Matter, Mike Jackson, Holly Haney

High School Lesson Plans

Students will investigate the relationship(s) between thermal and electrical properties of matter. First, students will use a multimeter and temperature probe to investigate the relationship between electrical resistance and temperature of an electrical resistor composed of metals. They will then graph collected data to analyze the relationship and draw a conclusion as to their relationship. They will then perform the same investigation on a thermal resistor made of a semiconducting substance and analyze that collected data. Finally, using ClaimEvidence-Reasoning (CER) structure, students will use their experimental evidence to state the similarities and differences between the electro-thermal properties of metals and …

A Neuromorphic Quadratic, Integrate, And Fire Silicon Neuron With Adaptive Gain, David Parent, Eric Basham

Faculty Publications

An integrated circuit implementation of a silicon neuron was designed, manufactured, and tested. The circuit was designed using the Quadratic, Integrate, and Fire (QIF) neuron model in 0.5 µm silicon technology. The neuron implementation was optimized for low current consumption, drawing only 1.56 mA per QIF circuit and utilized hysteretic reset, non-inverting integrator, and voltage-squarer circuits. The final area of each circuit in silicon was 268 µm height × 400 µm width. This design is the first IC of its kind for this neuron model and is successfully able to output true spiking that follows the behaviors of bistability, monotonic, …

Grasp Synthesis For Purposeful Fracturing Of Object, Mahyar Abdeetedal, Mehrdad Kermani Ph.D., P.Eng.

Electrical and Computer Engineering Publications

No abstract provided.

What Can I Do As A Student To Make A Positive Impact On The Environment?, Tammy Guthrie, Greg Herzig, Kathy Prophet, Cassie Kautzer

Middle School Lesson Plans

Students discover ways they can make a positive impact on the environment.

Wireless Sensors For Health Monitoring Of Marine Structures And Machinery, Francisco David Rojas Calvente

PhDs

Remote structural and machinery health monitoring (SMHM) of marine structures such as ships, oil and gas rigs, freight container terminals, and marine energy platforms can ensure their reliability. However, the wired sensors currently used in these applications are difficult and expensive to install and maintain. Wireless Sensor Networks (WSN) can potentially replace them but there are significant capability gaps that currently prevent their long-term deployment in the harsh marine environment and the structurally-complex, compartmentalised, all-metal scenarios with high volume occupancy of piping, ducting and operational machinery represented by marine structures. These gaps are in sensing, processing and communication hardware and …

Experience Constructing The Artifact Genome Project (Agp): Managing The Domain's Knowledge One Artifact At A Time, Cinthya Grajeda, Laura Sanchez, Ibrahim Baggili, Devon R. Clark, Frank Breitinger

Electrical & Computer Engineering and Computer Science Faculty Publications

While various tools have been created to assist the digital forensics community with acquiring, processing, and organizing evidence and indicating the existence of artifacts, very few attempts have been made to establish a centralized system for archiving artifacts. The Artifact Genome Project (AGP) has aimed to create the largest vetted and freely available digital forensics repository for Curated Forensic Artifacts (CuFAs). This paper details the experience of building, implementing, and maintaining such a system by sharing design decisions, lessons learned, and future work. We also discuss the impact of AGP in both the professional and academic realms of digital forensics. …

Automated Impact Response Sounding For Accelerated Concrete Bridge Deck Inspection, Jacob Lynn Larsen

Theses and Dissertations

Infrastructure deterioration is an international problem requiring significant attention. One particular manifestation of this deterioration is the occurrence of sub-surface cracking (delaminations) in reinforced concrete bridge decks. Of many techniques available for inspection, air-coupled impact-echo testing, or sounding, is a non-destructive evaluation technique to determine the presence and location of delaminations based upon the acoustic response of a bridge deck when struck by an impactor. In this work, two automated air-coupled impact echo sounding devices were designed and constructed. Each device included fast and repeatable impactors, moving platforms for traveling across a bridge deck, microphones for air-coupled sensing, distance measurement …

Power Electronics Powertrain Architectures For Hybrid And Solar Electric Airplanes With Distributed Propulsion, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Distributed propulsion in aircraft has been shown to increase reliability and benefit aerodynamic performance. This paper discusses power electronic architectures and proposes control schemes suitable for distributed propulsion in hybrid and electric airplanes. Hybrid electric airplanes include permanent magnet synchronous generators driven by jet engines. The output of the generators is connected to the propulsion motors through back to back voltage source converters. Batteries, connected to the DC bus through buck-boost converters, are used to provide additional power to the propulsion motors during take off and climb. In the case of electric airplanes, the jet engine-permanent magnet generator system is …

Adaptive Spaceship Cockpit Architecture, Ondřej Doule

Theses and Dissertations

This research project is focused on a system design theory and practice of the most complex environment that a human-system architect can ever encounter. It is the environment of the spaceship cockpit or cabin that is affected by forces of propulsion and gravity accelerations and freefall while the direction and magnitude of gravity change during the flight. Furthermore, the hyperbaric, restrictive environment of Intra Vehicular Activity spacesuit adds another layer of complexity. In off-nominal or emergency situations, these environmental effects combine, which results in specific human-system interaction requirements. Considering human-system integration requirements on safety, comfort and efficiency of communication between …

Discontinuous Galerkin Time-Domain Modeling Of Graphene Nanoribbon Incorporating The Spatial Dispersion Effects, Ping Li, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

It is well known that graphene demonstrates spatial dispersion properties, i.e., its conductivity is nonlocal and a function of spectral wavenumber (momentum operator) q. In this paper, to account for effects of spatial dispersion on transmission of high-speed signals along graphene nanoribbon (GNR) interconnects, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed. The atomically thick GNR is modeled using a nonlocal transparent surface impedance boundary condition (SIBC) incorporated into the DGTD scheme. Since the conductivity is a complicated function of q (and one cannot find an analytical Fourier transform pair between q and spatial differential operators), an exact time-domain SIBC …

Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

In this review, some major aspects of the current underfill technologies for flip-chip (FC) and fine-pitch-ball-grid-array (FPBGA), including chip-size packaging (CSP), are addressed, with an emphasis on applications, such as aerospace electronics, for which high reliability level is imperative. The following aspects of the FC and FPGGA technologies are considered: attributes of the FC and FPBGA structures and technologies; underfill-induced stresses; the roles of the glass transition temperature (T_g) of the underfill materials; some major attributes of the lead-free solder systems with underfill; reliability-related issues; thermal fatigue of the underfilled solder joints; warpage-related issues; attributes of accelerated life …

Multiuser Coding And Signal Processing In A Low Power Sensor Network, Dongqi Lai

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Backscatter communication system is a wireless communication system that is used by both academic community and industry circles in recent years. This communication system only requires ultra-low power usage and simple design of the sensors. This project is using backscatter communication system to transmit data with backscatter tags. The method we used is semi-passive backscatter communication. This project focuses on transmitting signals with multiple sensors so there is a problem about distinguishing the signal reflected by different nodes. We modulated the transmitting digital signal with Walsh function to solve the problem of separating the signals between different nodes. By using …

Implementation Of Vision Processing Tasks On A Smart Camera Platform Using Neighborhood Processors, Dingyi Hong

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Two applications of vision processing on a smart camera platform using neighborhood processors are presented. A smart camera application of real-time trajectory calculation for tracking objects and predicting their path of motion by using a single intelligent camera or a dual camera system are designed, simulated and implemented. Another application of object recognition with a key points algorithm for detecting simple shaped objects and locating the camera position within a 3-D coordinate system via imaging by using artificial neural network is applied to provide quick and accurate processing on a neighborhood-level parallel processor or other limited vision chip. For all …

Developmental Steps For A Functional Three-Dimensional Cell Culture System For The Study Of Asymmetrical Division Of Neural Stem Cells, Martina Zamponi

Biomedical Engineering Theses & Dissertations

Stem cells are a cell type present during and following development, which possess self- renewal properties, as well as the ability to differentiate into specific cells. Asymmetrical division is the cellular process that allows stem cells to produce one differentiated and one un-differentiated daughter cell during the same mitotic event. Insights in the molecular mechanisms of such process are minimal, due to the absence of effective methods for its targeted study. Currently, traditional methods of investigation include monolayer cell culture and animal models. The first poses structural limitations to the accurate representation of human tissue and cell structures, while animal …

Optimization Of Top Contact For Cu(In,Ga)Se2 Solar Cells, Grace Cherukara Rajan

Electrical & Computer Engineering Theses & Dissertations

As world energy demands continue to increase, the need to generate electricity from a broader variety of sources, including renewables, is more critical than ever. With costs still 30% higher than those of natural gas, solar energy is a viable contender, but more progress is needed to level the playing field with other forms of energy generation. The overall energy security can be enhanced by diversifying the energy supply. Among them, Cu(In,Ga)Se₂ (CIGS) has gained significant momentum as a possible high efficiency and low cost thin film solar cell material. The capacity to scale up any photovoltaic technology is …

Generation Of Large-Volume Diffuse Plasma By An External Ionization Wave From A Single-Electrode Plasma Jet, Seyed Hamid Razavi Barzoki

Electrical & Computer Engineering Theses & Dissertations

A non-thermal transient diffuse plasma can be generated remotely in a nonconductive reduced pressure chamber by an external guided fast ionization wave (FIW). We found that an atmospheric-pressure low-temperature plasma jet (APPJ) can be a source of FIW which transfers an enhanced electric field at the wave front across a reduced pressure Pyrex glass chamber with no electrical connection to the chamber. Here, we studied the formation and propagation of the APPJ plasma, the interaction of atmospheric-pressure guided FIW with a dielectric surface which forms the wall of the reduced-pressure system, and the formation and propagation of the reduce-pressure FIW …

Comparative Study Of Different Sensor Array Designs Involving Plasticized Polymer Coatings For Btex Detection In Water, Nicholas Post

Master's Theses (2009 -)

Detection and quantification of benzene, toluene, ethylbenzene, and xylenes (BTEX) in liquid phase is of interest because of the significant public health hazards posed by these compounds. BTEX are volatile organic compounds (VOCs) commonly used as additives in gasoline. Shear horizontal surface acoustic wave (SH-SAW) devices have shown promise in liquid phase sensing applications and is used to address this problem. SH-SAW devices can be made chemically sensitive by depositing a polymer coating on the device surface. SH-SAW devices coated with commercially available polymers have shown modest sensitivity to BTEX compounds. However, there are few polymers which exhibit the properties …

Design Day Analysis - Forecasting Extreme Daily Natural Gas Demand, David Joseph Kaftan

Master's Theses (2009 -)

This work provides a framework for Design Day analysis. First, we estimate the temperature conditions which are expected to be colder than all but one day in N years. This temperature is known as the Design Day condition. Then, we forecast an upper bound on natural gas demand when temperature is at the Design Day condition. Natural gas distribution companies (LDCs) need to meet demand during extreme cold days. Just as bridge builders design for a nominal load, natural gas distribution companies need to design for a nominal temperature. This nominal temperature is the Design Day condition. The Design Day …

Search Methods For Mobile Manipulator Performance Measurement, Samuel Nana Yaw Amoako-Frimpong

Master's Theses (2009 -)

Mobile manipulators are a potential solution to the increasing need for additional flexibility and mobility in industrial robotics applications. However, they tend to lack the accuracy and precision achieved by fixed manipulators, especially in scenarios where both the manipulator and the autonomous vehicle move simultaneously. This thesis analyzes the problem of dynamically evaluating the positioning error of mobile manipulators. In particular, it investigates the use of Bayesian methods to predict the position of the end-effector in the presence of uncertainty propagated from the mobile platform. Simulations and real-world experiments are carried out to test the proposed method against a deterministic …

Correction To: Dependability Enhancing Mechanisms For Integrated Clinical Environments (Vol 73, Pg 4207, 2017), Wenbing Zhao, Mary Q. Yang

Electrical and Computer Engineering Faculty Publications

No abstract provided.

Surrogate Affine Approximation Based Co-Optimization Of Transactive Flexibility, Uncertainty, And Energy, Hongzing Ye

Electrical and Computer Engineering Faculty Publications

This study presents an approach to co-optimization of transactive flexibility, energy, and optimal injection-range of Variable Energy Resource (VER). Flexibility receives immense attention, as it is the essential resource to accommodate VERs in modern power systems. With a novel concept of transactive flexibility, the proposed approach proactively positions the flexible resources and optimizes the demand of flexibility. A surrogate affine approximation (SAA) method is proposed to solve the problem with variable infinite-constraint range in polynomial time. It is shown that SAA is more optimistic than the traditional affine policy in the power literature. The SAA method is also applicable to …

Body Armor Shape Sensing With Fiber Optic Sensors, Frederick Alexander Seng

Theses and Dissertations

In this dissertation, the rate of the BFD during body armor impact is characterized with fiber Bragg gratings for the first time ever. The depth rate is characterized using a single fiber optic sensor, while the entire shape rate can be characterized using multiple fiber optic sensors. This is done with a final depth accuracy of less than 10% and a timing accuracy of 15% for BFDs as deep as 50 mm and impact event of less than 1 millisecond. The shape sensing method introduced in this dissertation is different from traditional fiber optic sensor shape reconstruction methods in the …

An Empirical Path Loss Model For Wireless Sensor Network Deployment In A Library Environment, Thomas John Misilo

Theses and Dissertations

Wireless networks are becoming more commonplace which has necessitated the know-how to optimally place the devices. There have been studies using wireless sensor networks inside of libraries and museums. However, extensive research has not been completed on propagation modeling for use in the library environment. The main aim of this research is to provide a propagation path loss model for a typical library environment, while comparing two types of antennas (wire and small dipole antenna). This research develops path loss models for a peer-to-peer 2.4 GHz system, where both the transmitter and the receiver are located at the same elevated …

Improvements For Vision-Based Navigation Of Small, Fixed-Wing Unmanned Aerial Vehicles, Robert C. Leishman, Jeremy Gray, John F. Raquet, Adam Rutkowski

Faculty Publications

Investigating alternative navigation approaches for use when GPS signals are unavailable is an active area of research across the globe. In this paper we focus on the navigation of small, fixed-wing unmanned aerial vehicles (UAVs) that employ vision-based approaches combined with other measurements as a replacement for GPS. We demonstrate with flight test data that vehicle attitude information, derived from cheap, MEMS-based IMUs is sufficient to improve two different types of vision processing algorithms. Secondly, we show analytically and with flight test data that range measurements to one other vehicle with global pose is sufficient to constrain the global drift …

Solid Oxide Electrochemical Cells For High Temperature Hydrogen Production: Theory, Fabrication And Characterization, Can Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

In this dissertation, the concept of water splitting using solid oxide photoelectrochemical cells (SOPCs) at high temperature was introduced and experimentally investigated. High temperature photoelectrochemical water splitting physically broadens the selection of potential applicable semiconductor materials and enables more visible sunlight absorption. This newly conceived concept provides a unique pathway for solar hydrogen production, as compared to conventional photoelectrochemical cells (PECs) that use wide band gap semiconductors in aqueous environments. The theoretical framework of SOPC was elaborated, followed by the experimental investigation to search for appropriate high temperature materials. Selected high temperature Schottky and p-n junction diodes, which were expected …

Evaluation And Design Improvement Of An Augmentative And Alternative Communication Tool For Children With Autism, Moez Lidinallah Fessi

Theses and Dissertations

Autism Spectrum Disorder treatment is a real challenge in our society. In an attempt to manage this, Augmentative and Alternative Communication devices became more and more prevalent in the form of software installed on portable devices such as tablets. These mobile applications help individuals with autism to enhance their communication capabilities. Some of the concerns pertaining to the success these systems are the efficacy and the capability, the ease of use, and the user engagement. The research described in this thesis focuses on the usability of a particular application named Livox. This usability evaluation consisted of a threefold approach: (1) …