Electrical and Computer Engineering Commons^™

Communicating In A Socially-Aware Network: Impact Of Relationship Types, Basak Guler, Burak Varan, Kaya Tutuncuoglu, Mohamed Nafea, Ahmed A. Zewail, Aylin Yener, Damien Octeau

Electrical and Computer Engineering Faculty Research & Creative Works

Communication networks are linked to and influenced by human interactions. Socially aware systems should integrate these complex relationship patterns in the network design. This paper studies the impact of friendship and antagonistic relationships between individuals on optimal network propagation policies. We develop a network propagation model for signed networks and determine the optimal policies to influence a target node with an opinion while minimizing the total number of persons against it. We also provide extensions to this problem to elaborate on the impact of network parameters, such as minimum-delay propagation, while limiting the number of persons influenced against the idea …

Contrast Enhancement Using Silica Microspheres In Coherent Anti-Stokes Raman Spectroscopic Imaging, X. Huang, X. N. He, W. Xiong, Y. Gao, L. J. Jiang, Li Liu, Y. S. Zhou, L. Jiang, J. F. Silvain, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Coherent anti-Stokes Raman scattering (CARS) microscopy is a powerful imaging technique that can provide chemical information of organic and nonorganic materials through vibrational spectroscopy. However, its contrast is not sufficient for monitoring thin film materials. In this study, silica microspheres were employed for enhancing the signal contrast in CARS imaging. One layer of optically transparent silica microspheres was self-assembled onto polymer grating samples to enhance the CARS signals. The highest contrast enhancement factor of 12.5 was achieved using 6.1-μm-diameter microspheres. Finite-difference timedomain method (FDTD) simulation was conducted to simulate the contrast enhancement with silica microspheres of different diameters.

Electronic Structure Characterization Of Hybrid Materials, Zhi Li

USF Tampa Graduate Theses and Dissertations

In this dissertation, the studies aim to characterize the electronic structure at the internal interface of hybrid materials. The characterization challenge is originating from the spectral superposition of hybrid constituents. A characterization protocol based on photoemission spectroscopy (PES) was developed and applied to investigate the orbital alignment at the internal interface of the oligothiophene-TiO2 and ArS-CdSe hybrid materials by characterizing the individual constituents and the assembly hybrids respectively. Electrospray deposition technique was used to deposit targeting materials which enabled preparation of thin films in vacuum minimizing ambient contaminations while transmission electron microscopy (TEM) was used to investigate the morphology and …

Investigation Of Profiled Beam Propagation Through A Turbulent Layer And Temporal Statistics Of Diffracted Output For A Modified Von Karman Phase Screen, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

Electrical and Computer Engineering Faculty Publications

Gaussian beam propagation through a turbulent layer has been studied using a split-step methodology. A modified von Karman spectrum (MVKS) model is used to describe the random behavior of the turbulent media. Accordingly, the beam is alternately propagated (i) through a thin Fresnel layer, and hence subjected to diffraction; and (ii) across a thin modified von Karman phase screen which is generated using the power spectral density (PSD) of the random phase obtained via the corresponding PSD of the medium refractive index for MVKS turbulence.

The random phase screen in the transverse plane is generated from the phase PSD by …

Numerical Inversion And Assessment Of 2d Laplace Transforms Using The Brancik Algorithm And Its Use In 3d Holography, Monish Ranjan Chatterjee, Le Feng

Electrical and Computer Engineering Faculty Publications

An analytic examination of 3D holography under a 90° recording geometry was carried out earlier in which 2D spatial Laplace transforms were introduced in order to develop transfer functions for the scattered outputs under readout [1,2].

Thereby, the resulting reconstructed output was obtained in the 2D Laplace domain whence the spatial information would be found only by performing a 2D Laplace inversion. Laplace inversion in 2D was attempted by testing a prototype function for which the analytic result was known using two known inversion algorithms, viz., the Brancik and the Abate [2]. The results indicated notable differences in the 3D …

Second-Harmonic Double-Resonance Cones In Dispersive Hyperbolic Metamaterials, Domenico De Ceglia, Maria Antonietta Vincenti, Salvatore Campione, Filippo Capolino, Joseph W. Haus, Michael Scalora

Electrical and Computer Engineering Faculty Publications

We study the formation of second-harmonic double-resonance cones in hyperbolic metamaterials. An electric dipole on the surface of the structure induces second-harmonic light to propagate into two distinct volume plasmon-polariton channels: a signal that propagates within its own peculiar resonance cone and a phase-locked signal that is trapped under the pump's resonance cone. Metamaterial dispersion and birefringence induce a large angular divergence between the two volume plasmon polaritons, making these structures suitable for subwavelength second- and higher-harmonic imaging microscopy.

A 1 Gs/S, 31 Mhz Bw, 76.3 Db Dynamic Range, 34 Mw Ct-Δς Adc With 1.5 Cycle Quantizer Delay And Improved Stf, Sakkarapani Balagopal, Kehan Zhu, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

A 1 GS/s continuous-time delta-sigma modulator (CT- ΔΣM) with 31 MHz bandwidth, 76.3 dB dynamic range and 72.5 dB peak-SNDR is reported in a 0.13 μm CMOS technology. The design employs an excess loop delay (ELD) of more than one clock cycle for achieving higher sampling rate. The ELD is compensated using a fast-loop formed around the last integrator by using a sample-and-hold. Further, the effect of this ELD compensation scheme on the signal transfer function (STF) of a feedforward CT- ΔΣ architecture has been analyzed and reported. In this work, an improved STF is achieved by using a combination …

An Event-Based Simulation Framework To Examine The Response Of Power Grid To The Charging Demand Of Plug-In Hybrid Electric Vehicles, Zahra Darabi, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes the development of a discrete-event simulation framework that emulates the interactions between the power grid and plug-in hybrid electric vehicles (PHEVs) and examines whether the capacity of the existing power system can meet the PHEV load demand. The probability distribution functions for the arrival time and energy demand of each vehicle are extracted from real-world statistical transportation data. The power grid's limited generation and transmission capacities are considered to be the major constraints. Therefore, vehicles may have to wait to receive any charge. The proposed simulation framework is justified and described in some detail in applying it …

Energy Efficiency And Spectral Efficiency Tradeoff In Type-I Arq Systems, Jingxian Wu, Gang Wang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

The optimum energy efficient and spectral efficient designs for type-I automatic-repeat-request (ARQ) systems in Rayleigh flat fading channels are studied in this paper. Three optimum designs are considered: the first scheme maximizes the energy efficiency (EE), or equivalently, minimizes the total energy per information bit without considering the spectral efficiency (SE); the second scheme minimizes a new metric, the energy per information bit normalized by the SE; and the third scheme maximizes the EE under the constraint of a minimum SE. For given physical and link layer parameters, such as hardware power consumption, coding rate, modulation, bit rate, number of …

On The Use Of Gaussian Approximation In Analyzing The Performance Of Optical Receivers, George El-Howayek, C. Zhang, Y. Li, J. S. Ng, J. P.R. David, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

The analytical calculation of the bit error rate (BER) of digital optical receivers that employ avalanche photodiodes (APDs) is challenging due to 1) the stochastic nature of the avalanche photodiode's impulse-response function and 2) the presence of intersymbol interference (ISI). At ultrafast transmission rates, ISI becomes a dominant component of the BER, and its effect on the BER should be carefully addressed. One solution to this problem, termed the bit-pattern-dependent (PD) approach, is to first calculate the conditional BER given a specific bit pattern and then average over all possible bit patterns. Alternatively, a simplifying method, termed the bit-pattern-independent (PI) …

Speech Enhancement Using Bayesian Estimators Of The Perceptually-Motivated Short-Time Spectral Amplitude (Stsa) With Chi Speech Priors, Marek B. Trawicki, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, the authors propose new perceptually-motivated Weighted Euclidean (WE) and Weighted Cosh (WCOSH) estimators that utilize more appropriate Chi statistical models for the speech prior with Gaussian statistical models for the noise likelihood. Whereas the perceptually-motivated WE and WCOSH cost functions emphasized spectral valleys rather than spectral peaks (formants) and indirectly accounted for auditory masking effects, the incorporation of the Chi distribution statistical models demonstrated distinct improvement over the Rayleigh statistical models for the speech prior. The estimators incorporate both weighting law and shape parameters on the cost functions and distributions. Performance is evaluated in terms of the …

Characterization If Li-Air Batteries Influence Of Cathode Degradation: Demonstration Of Progress, Claudia Torres Garibay, Jeremiah Deboever

TREC Project Briefs

Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against fossil fuel powered vehicles. However, Li-air battery technology is considered to be far from commercialization, due to its short lifespan. The decomposition of the electrolyte and its effect on cyclablity has been widely studied, no so much the cathode. The presence of undesirable reaction by-products at the cathode that affect the battery performance has been quantified through XRD and SEM. This work will make use of recently reported novel …

Optical Properties Of Solar Cells Based On Zinc(Hydr)Oxide And Its Composite With Graphite Oxide Sensitized By Quantum Dots, S. M. Zakirul Islam

Dissertations, Theses, and Capstone Projects

This thesis research focuses on developing a hybrid form of solar cell based on zinc(hydr)oxide and its composites with graphite oxide, TiO2, quantum dot, electrolyte and . This work expands upon the Gratzel solar cell with a dye in TiO2.

Due to various structural and optical characteristics, zinc(hydr)oxide (Zn(OH)2) and its porous composites with 2% and 5% graphite oxide(GO) can be used for various applications including the manufacture of various , protective elements in electric and electronic appliances, as gas-sensors, catalysts, in cosmetics a UV light absorber, and solar cells.

In this research, both TiO2 and zinc(hydr)oxide (refer as Zn(OH)2 …

On The Merits Of Deploying Tdm-Based Next-Generation Pon Solutions In The Access Arena As Multiservice, All Packet-Based 4g Mobile Backhaul Ran Architecture, Syed Rashid N. Zaidi

Dissertations, Theses, and Capstone Projects

The phenomenal growth of mobile backhaul capacity required to support the emerging fourth-generation (4G) traffic including mobile WiMAX, cellular Long-Term Evolution (LTE), and LTE-Advanced (LTE-A) requires rapid migration from today's legacy circuit switched T1/E1 wireline and microwave backhaul technologies to a new fiber-supported, all-packet-based mobile backhaul infrastructure. Clearly, a cost effective fiber supported all-packet-based mobile backhaul radio access network (RAN) architecture that is compatible with these inherently distributed 4G RAN architectures is needed to efficiently scale current mobile backhaul networks. However, deploying a green fiber-based mobile backhaul infrastructure is a costly proposition mainly due to the significant cost associated with …

Model Predictive Control Of Timed Continuous Petri Nets, Huaiyu Zhan

Theses

This thesis addresses the optimal control problem of timed continuous Petri nets. The theory of Model Predictive Control (MPC) is first discussed. Then continuous Petri nets (PN) are introduced as a powerful tool for modelling, simulation and analysis of discrete event/continuous systems. Their useful capabilities are studied. Finally, a macroscopic model based on PN as a tool for designing control laws that improve the behavior of traffic systems is given. The goal is to find an approach that minimizes the total delay of cars in an intersection by computing the switching sequence of the traffic lights. The simulation results show …

Multi-Terminal Networks With An Untrusted Relay, Ahmed A. Zewail, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the impact of cooperation with an untrusted relay in multi-source multi-destination networks. The set up considered is one where the relay is the only means of communications due to the absence of direct links between the sources and the destinations. Since the relay is untrusted, all messages from the sources need to be kept secret from the relay. Furthermore, the destinations are assumed to have different levels of security clearance, i.e., some private messages should only be decoded by their intended receiver and should be kept secret from other destinations. An achievable secure rate region is found …

Development Of Instruments For The Diagnosis And Treatment Of Hydrocephalus, Ryan T. Ochsner, Dr. Mark Manwaring

Journal of Undergraduate Research

The Brain Instrumentation Laboratory (1220 SWKT) associated with the Department of Neuroscience and Electrical and Computer Engineering at Brigham Young University specializes in the development of new technologies which may facilitate the management of diseases of the brain. Of specific interest to the laboratory is the improved treatment of hydrocephalus. Hydrocephalus is a condition which results in progressive damage to the brain because of tremendous pressure when cerebral spinal fluid (CFS) is not absorbed as fast as it is produced. This condition results in increasing ventricle size within the brain and associated pressure and deformation.

Real-Time Adaptive Cancellation Of Non-Stationary Interference In Radio Astronomy, Andrew Poulsen, Dr. Brian Jeffs

Journal of Undergraduate Research

When images of remote galaxies/stars are observed by radio telescope, much sensitivity can be blurred by interference. This interference can be caused by both the atmosphere and man-made sources. Specifically, the Russian GLONASS satellite system transmits data at a bandwidth wherein much information important to radio astronomers is radiated by astronomical objects. A real-time DSP-based system is needed to adaptively remove the interfering signals and restore clarity to the radio astronomy signal.

Stereogram Printer, Daniel E. Smalley, Dr. Richard H. Selfridge

Journal of Undergraduate Research

The goal of this creative works project was to build an inexpensive Stereogram printer capable of producing three-dimensional images from a series of two-dimensional pictures. This type of printer is very useful for making hologram-like images of objects and scenes that would be impossible to ‘holograph’ by traditional, optical methods. Though several printers of this type have already been built, they generally cost several thousands of dollars to develop. The author built the following small-scale printer primarily from a $200 LCD television and a $10 scanner. (However, it should be noted that this piece of equipment had to be run …

The Brain’S Response To Music Using Fmri, Todd Harris, Dr. Travis Oliphant

Journal of Undergraduate Research

While it is obvious that hearing a sound produces measurable changes in the brain’s auditory cortex, it is less clear how a compilation of tones, beats, and rhythms affect other areas. In this study I use fMRI to observe which structures in the brain become active in response to music in three male subjects. My results show that different music pieces have unique and measurable affects on the brain. A strong determining factor on the effect that music has is the familiarity of the music to the listener. Results show that familiar music reduces overall brain activity while stimulating a …

Gps Navigation Module For The Handspring Visor Pda, Craig Cody, Craig Tingey, Richard Helps

Journal of Undergraduate Research

The focus of our research project was to build a GPS navigation module to be used with the Handspring PDA. It provides a highly mobile method of finding exact locations using an interface and display that is familiar and friendly. Our GPS module fits into the Springboard expansion slot. With it, any Handspring user is able to choose from many available Palm OS location and positioning programs to harness GPS information wherever they choose to go. Research into GPS receivers began about two years ago with a project to build a high frequency antenna and low-noise amplifier to receive the …

Gps Navigation Module For The Handspring Visor Pda, Craig Cody Hardcastle, Craig Tingey, Richard Helps

Journal of Undergraduate Research

The focus of our research project was to build a GPS navigation module to be used with the Handspring PDA. It provides a highly mobile method of finding exact locations using an interface and display that is familiar and friendly. Our GPS module fits into the Springboard expansion slot. With it, any Handspring user is able to choose from many available Palm OS location and positioning programs to harness GPS information wherever they choose to go. Research into GPS receivers began about two years ago with a project to build a high frequency antenna and low-noise amplifier to receive the …

Fmri Investigation Of Brain Function While Reading Different Types Of Literature, David A. Thayer, Dr. Travis Oliphant

Journal of Undergraduate Research

Functional Magnetic Resonance Imaging is a new imaging technique that results in images showing what areas of the brain are active during different activities. In spite of the popularity of this new technology there are no commonly available or widely accepted programs for processing fMRI data. The purpose of this research was to develop an fMRI analysis program, design a simple fMRI experiment, select MRI imaging parameters for fMRI, show that the program provides useful results, and then explore the results of another fMRI research experiment. This project’s focus turned more towards image processing than actual brain function mapping, as …

The Brain’S Response To Physical Activity Studied With Fmri, Ren Weidman, Dr. Travis Oliphant

Journal of Undergraduate Research

In recent years the fields of medicine and physiological research have made many advancements as a result of application of technology. One example of this is the device known as the Magnetic Resonance Imaging machine (MRI). MRI machines use innovative methods based on principles of physics and electronics to effectively attain a cross-sectional view of the human body. The MRI machine emits an electromagnetic field in the presence of a static field to manipulate the nuclear spin of hydrogen atoms in the body. The received signal can then be interpreted and reconstructed to plot a picture of the section examined. …

An Analysis Of Beowulf Supercomputing Clusters, And Their Potential Application In Higher Education, Curtis R. Nielson, C. Richard G. Helps

Journal of Undergraduate Research

A supercomputer may be defined as a computer that leads the world in processing capacity, particularly in terms of calculation speed. Historically, the processing power of a supercomputer has been reserved for government or scientific research agencies; however, advances in computing technology have made the supercomputer an obtainable tool for academia. The Information Age has generated enormous amounts of data, which often require the processing capacity of a supercomputer for proper analysis. Modern supercomputers are well equipped to handle the demands of most data manipulations, but their cost is usually in the millions. A supercomputer design growing in popularity is …

Enhanced High-Alphabet Fm For A Flight Termination System, Brent Allen Kenney, Dr. Michael D. Rice

Journal of Undergraduate Research

The BYU Telemetry Lab has functioned in a consulting role for NASA’s Enhanced Flight Termination System (EFTS) group since 2000. NASA initiated the EFTS program to develop a new system to be used on their many test ranges for unmanned flight vehicles throughout the country. In the event that a flight vehicle loses control and threatens to endanger lives, the EFTS will place the vehicle in a zero-thrust state either by parachute or planned explosion. To ensure safety, the desired feature of EFTS is the reliability or the communication link rather than high data throughput.

Pmu-Based Adaptive Central Protection Unit (Cpu) For Power Systems With High Dg Penetration, Pooria Mohammadi

Electrical Engineering Theses

The rapid expansion and integration of Distributed Generations (DG) into power systems plays an increasingly important role in their planning, operation, and control. The rules used to design and operate current systems are being altered by the DGs incorporation. This may jeopardize the system's reliability and security. Private owners of large DGs should not be restricted to a particular time schedule to connect/disconnect their generation to/from the system. This feature dynamically changes the typical power system with unidirectional power flow from generation to the loads. A smart Central Protection Unit (CPU) is needed to take proper measures in case of …

Model-Free Q-Learning Over Finite Horizon For Uncertain Linear Continuous-Time Systems, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel optimal control over finite horizon has been introduced for linear continuous-time systems by using adaptive dynamic programming (ADP). First, a new time-varying Q-function parameterization and its estimator are introduced. Subsequently, Q-function estimator is tuned online by using both Bellman equation in integral form and terminal cost. Eventually, near optimal control gain is obtained by using the Q-function estimator. All the closed-loop signals are shown to be bounded by using Lyapunov stability analysis where bounds are functions of initial conditions and final time while the estimated control signal converges close to the optimal value. The simulation …

Event-Based Optimal Regulator Design For Nonlinear Networked Control Systems, Avimanyu Sahoo, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel stochastic event-based near optimal control strategy to regulate a networked control system (NCS) represented as an uncertain nonlinear continuous time system. An online stochastic actor-critic neural network (NN) based approach is utilized to achieve the near optimal regulation in the presence of network constraints, such as, network induced time-varying delays and random packet losses under event-based transmission of the feedback signals. The transformed nonlinear NCS in discrete-time after the incorporation the delays and packet losses are utilized for the actor-critic NN based controller design. To relax the knowledge of the control coefficient matrix, a NN …

Neural Network-Based Adaptive Optimal Consensus Control Of Leaderless Networked Mobile Robots, Haci Mehmet Guzey, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel neural network (NN)-based optimal adaptive consensus control scheme is introduced in this paper for networked mobile robots in the presence of unknown robot dynamics. Throughout the paper, two NNs are used. The unknown formation dynamics of each robot is identified by using the first NN. The second NN is utilized to approximate a novel value function derived in this paper as a function of augmented error vector, which is comprised of the regulation and consensus-based formation errors of each robot. A novel near optimal controller is developed by using approximated value function and identified formation dynamics. The Lyapunov …