Electrical and Computer Engineering Commons^™

Structural Identification Using A Low-Cost Search Method, James W. Fonda, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

An easily implementable and trainable damage detection method is proposed and implemented for a simple truss structure. The approach uses the iterative search identification method and is compatible with low-cost and low-power microcontroller hardware. This method employs pattern matching for a data set from a strain sensor array and predicts location (truss member) and severity (member cross sectional area) of damage. As a health monitoring approach, the method is not as robust or rigorous as more complex methods. However, it has modest processing requirements and can handle noisy signals. The work presents an algorithm applied to a truss structure, the …

Alan Turing Se Fraye Un Chemin Jusqu'À La Place De L'Ordinateur, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

A brief statement on the significance, impact and future developments related to the work of computer pioneer Alan Turing, in conjunction with Turing Day, held to commemorate his 90th birthday.

*The article is in French

Spectroscopicellipsometer And Polarmeter Systemis, John A. Woollam, Blaine D. Johs, Craig M. Herzinger, Ping He, Martin M. Liphardt, Galen L. Pfeiffer

Department of Electrical and Computer Engineering: Faculty Publications

A rotating compensator spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for Supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, the system being functionally present in an environmental control chamber and therefore suitable for application in wide spectral range, (for example, 130-1700 nm). Preferred compensator design involves a Substantially achromatic multiple element compensator systems wherein multiple total internal reflections enter retardance into an entered beam of electromagnetic radiation, and the elements thereof are oriented to minimize changes …

Atomic Force Microscopy Of Dna Self-Assembled Nanostructures For Device Applications, Hieu Bui, Craig Onodera, Bernard Yurke, Elton Graugnard, Wan Kuang, Jeunghoon Lee, William B. Knowlton, William L. Hughes

Electrical and Computer Engineering Faculty Publications and Presentations

DNA nanotechnology, which relies on Watson-Crick hybridization, is a versatile selfassembly process whereby a variety of complex nanostructures can be fabricated with sublithographic features.[1] Adopting this technology, 1012 identical devices can be synthesized to have hundreds of components with 1nm resolution. Example nanostructures include: 1) DNA motifs [2], 2) two-dimensional DNA crystals [3], and DNA origami [4]. Currently, this technology is being adopted towards electronic, optical, and opto-electronic devices.[5]

Graphene On Pt(111): Growth And Substrate Interaction, Peter Sutter, Jerzy T. Sadowski, Eli Sutter

Department of Electrical and Computer Engineering: Faculty Publications

In situ low-energy electron microscopy (LEEM) of graphene growth combined with measurements of the graphene structure and electronic band structure has been used to study graphene on Pt (111). Growth by carbon segregation produces macroscopic monolayer graphene domains extending continuously across Pt (111) substrate steps and bounded by strongly faceted edges. LEEM during cooling from the growth temperature shows the propagation of wrinkles in the graphene sheet, driven by thermal stress. The lattice mismatch between graphene and Pt (111) is accommodated by moiré structures with a large number of different rotational variants, without a clear preference for a particular interface …

Quality-Driven Cross Layer Design For Multimedia Security Over Resource Constrained Wireless Sensor Networks, Wei Wang

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

The strong need for security guarantee, e.g., integrity and authenticity, as well as privacy and confidentiality in wireless multimedia services has driven the development of an emerging research area in low cost Wireless Multimedia Sensor Networks (WMSNs). Unfortunately, those conventional encryption and authentication techniques cannot be applied directly to WMSNs due to inborn challenges such as extremely limited energy, computing and bandwidth resources. This dissertation provides a quality-driven security design and resource allocation framework for WMSNs. The contribution of this dissertation bridges the inter-disciplinary research gap between high layer multimedia signal processing and low layer computer networking. It formulates the …

College Of Engineering Senior Design Competition Fall 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Each student in his or her senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. The senior design project encourages the student to use everything learned in the engineering program to create a practical, real-world solution to an engineering challenge.

A highlight of the year-long senior design project is the senior design competition. This competition, which usually takes place the week before finals each semester, helps focus the senior students on increasing the quality and potential for commercial application for their design projects.

Judges from local industry evaluate the projects on innovation, commercial …

Design And Implementation Of A Neural Network Controller For Real-Time Adaptive Voltage Regulation, Xiao-Hua Yu, Weiming Li, N. F. N. Taufik

Electrical Engineering

An adaptive controller based on multi-layer feed-forward neural network is developed for real-time voltage regulation of a class of PSFB (phase-shifted full-bridge) DC–DC converters. The controller has the unique advantages of nonlinear mapping and adaptive learning, and performs well over a wide range of input voltages and output load currents. The controller is implemented and tested in hardware using a DSP (digital signal processor) board. Experimental results show that it outperforms conventional controllers in both line regulation and load regulation.

Design And Implementation Of A Neural Network Controller For Real-Time Adaptive Voltage Regulation, Xiao-Hua Yu, Weiming Li, Taufik

Electrical Engineering

An adaptive controller based on multi-layer feed-forward neural network is developed for real-time voltage regulation of a class of PSFB (phase-shifted full-bridge) DC–DC converters. The controller has the unique advantages of nonlinear mapping and adaptive learning, and performs well over a wide range of input voltages and output load currents. The controller is implemented and tested in hardware using a DSP (digital signal processor) board. Experimental results show that it outperforms conventional controllers in both line regulation and load regulation.

Reflective Optics Cpv Panels Enabling Large Scale, Reliable Generation Of Solar Energy Cost Competitive With Fossil Fuels, S. Horne, M. Mcdonald, N. Hartsoch, K. Desy

Publications (E)

The objective of this 18 month subcontract was the improvement of reflective optics CPV panels to enable the large-scale, reliable production of solar electricity to meet SAI-established LCOE targets, and ultimately provide a path to solar power at parity with or better than the cost of energy generated utilizing fossil fuels. To this end, SolFocus has completed this subcontract with great success as evidenced by the end results of a CPV panel with conversion efficiencies greater than the targeted 22% and manufacturing capabilities with a run rate capacity far exceeding the milestone benchmark >3MW.

Wind Energy And Power System Operations: A Review Of Wind Integration Studies To Date, Jennifer Decesaro, Kevin Porter

Publications (E)

This paper provides an overview of the challenges associated with wind integration and summarizes the findings of the wind integration studies conducted over the course of the past five years. We begin with an overview of the approximate time frames used in grid operations. We then describe how wind integration studies are conducted, discuss the results on wind integration costs and grid impacts from these grid integration studies, and assess some of the grid planning and operation changes that may be necessary to incorporate higher levels of wind generation. We close with several conclusions.

Camouflaging Timing Channels In Web Traffic, Sarah H. Sellke, Chih-Chun Wang, Saurabh Bagchi, Ness B. Shroff

Department of Electrical and Computer Engineering Technical Reports

Web traffic accounts for more than half of Internet traffic today. Camouflaging covert timing channels in Web traffic would be advantageous for concealment. In this paper, we investigate the possibility of disguising network covert timing channels as HTTP traffic to avoid detection. Extensive research has shown that Internet traffic, including HTTP traffic, exhibits self-similarity and long range persistence. Existing covert timing channels that mimic i.i.d. legitimate traffic cannot imitate HTTP traffic because these covert traffic patterns are not long range dependent. The goal of this work is to design a covert timing channel that can be camouflaged as HTTP traffic. …

A Parallel Direct Solver For The Simulation Of Large-Scale Power/Ground Networks, Stephen Cauley, Venkataramanan Balakrishnan, Cheng-Kok Koh

Department of Electrical and Computer Engineering Technical Reports

We present an algorithm for the fast and accurate simulation of power/ground mesh structures. Our method is a direct (non-iterative) approach for simulation based upon a parallel matrix inversion algorithm. Through the use of additional computational resources, this distributed computing technique facilitates the simulation of large-scale power/ground networks. In addition, the new dimension of flexibility provided by our algorithm allows for a more accurate analysis of power/ground mesh structures using RLC interconnect models. Specifically, we offer a method that employs a sparse approximate inverse technique to consider more reluctance coupling terms for increased accuracy of simulation. The inclusion of additional …

Ccack: Efficient Network Coding Based Opportunistic Routing Through Cumulative Coded Acknowledgments, Dimitrios Koutsonikolas, Chih-Chun Wang, Y. Charlie Hu

Department of Electrical and Computer Engineering Technical Reports

The use of random linear network coding (NC) has significantly simplified the design of opportunistic routing (OR) protocols by removing the need of coordination among forwarding nodes for avoiding duplicate transmissions. However, NC-based OR protocols face a new challenge: How many coded packets should each forwarder transmit? To avoid the overhead of feedback exchange, most practical existing NC-based OR protocols compute offline the expected number of transmissions for each forwarder using heuristics based on periodic measurements of the average link loss rates and the ETX metric. Although attractive due to their minimal coordination overhead, these approaches may suffer significant performance …

Singlemode-Multimode-Singlemode Optical Fibre Structures For Optical Sensing, Agus Muhamad Hatta

Doctoral

This thesis describes theoretical and experimental investigations on all-fibre multimode interference (MMI) devices using a singlemode-multimode-singlemode (SMS) fibre structure for use as a new type of edge filter for a ratiometric wavelength measurement system and as novel stand alone sensors. The use of two edge filters, so called X-type edge filters based on SMS fibre structures in a ratiometric wavelength measurement system is proposed and demonstrated. The use of X-type edge filters can improve the resolution and accuracy of wavelength measurement compared to the use of one edge filter in a conventional ratiometric system. Several aspects of the SMS edge …

Effect Of System Components On Electrical And Thermal Characteristics For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, parameterized electrical-thermal co-analysis for power delivery networks (PDN) in 3D system integration is carried out. A 3D integrated system including glass-ceramic substrate, single and stacked dies, power delivery network, through-silicon vias (TSVs), controlled collapse chip connections (C4s), underfill material, and thermal interface material (TIM) is analyzed with several variable parameters. The analysis results show that temperature effects on DC IR drop can not be neglected. The TIM thermal conductivity, C4 density, stacking order of stacked dies, and voltage source location affect the final IR drop and hot spot temperature in the system. ©2009 IEEE.

On The Dual Basis For Solving Electromagnetic Surface Integral Equations, Mei Song Tong, Weng Cho Chew, Barry J. Rubin, Jason D. Morsey, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A powerful technique for solving electromagnetic (EM) surface integral equations (SIEs) for inhomogenous objects by the method of moments (MoM) involves the well-known RaoWiltonGlisson (RWG) basis function to represent the electric current and, for field orthogonality and numerical stability reasons, a variation of the RWG basis known as the ňx RWG basis (where ň is a unit normal vector at the object surface) to represent the magnetic current. Though this combination provides a numerically efficient and effective solution that has been demonstrated on a variety of structures, one cannot feel entirely comfortable because of the presence of fictitious magnetic current …

Compact Trench-Based Silicon-On-Insulator Rib Waveguide Ring Resonator With Large Free Spectral Range, Seunghyun Kim, Gregory P. Nordin, Weisheng Hu, Yusheng Qian, Jiguo Song, Gregory L. Wojcik

Faculty Publications

We demonstrate a compact trench-based silicon-on-insulator (SOI) rib waveguide ring resonator comprised of trench-based bends and splitters. It has a perimeter of 50 μm and occupies an area of only 25×25 μm. The measured free spectral range (FSR) is 13.2 nm, which the largest reported for an SOI rib waveguide ring resonator. The measured FSR, full width at half maximum, and quality factor match reasonably well with analytical calculations. Further calculation shows that a FSR of 50.8 nm is achievable for an SOI rib waveguide ring resonator with a perimeter of 15 μm.

Gain Guiding In Large-Core Bragg Fibers, Xianyu Ao, Tsing-Hua Her, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

We theoretically analyze gain guiding in large-core Bragg fibers, to be used for large-mode-area laser amplifiers with single-transverse-mode operation. The signal is gain-guided in a low-index core, whereas the pump is guided by the photonic bandgap of the Bragg cladding to achieve good confinement. The high-index layers in the Bragg cladding are half-wave thick at the signal wavelength in order to eliminate Bragg reflection, reducing the Bragg fiber effectively to a step-index fiber for gain guiding.

Electrical-Thermal Co-Analysis For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an electrical-thermal co-analysis method for power delivery networks in 3D system integration is proposed. For electrical analysis, temperature-dependent electrical resistivity of conductors is taken into account. For thermal analysis, Joule heating effect due to the current flowing through conductors is considered. The proposed co-analysis method is carried out using Rgen and ChipJoule of IBM EIP Tool Suite. An example of 3D integration system including stacked chips, power delivery network, glass-ceramic substrate, through-silicon vias, controlled collapse chip connections (C4s), underfill material, and TIM is analyzed using the proposed method. The simulation results show that the temperature effect on …

Electromagnetic Scattering Solutions For Digital Signal Processing, Jonathan Blackledge

Other resources

Electromagnetic scattering theory is fundamental to understanding the interaction between electromagnetic waves and inhomogeneous dielectric materials. The theory unpins the engineering of electromagnetic imaging systems over a broad range of frequencies, from optics to radio and microwave imaging, for example. Developing accurate scattering models is particularly important in the field of image understanding and the interpretation of electromagnetic signals generated by scattering events. To this end there are a number of approaches that can be taken. For relatively simple geometric configurations, approximation methods are used to develop a transformation from the object plane (where scattering events take place) to the …

Sensors: A Novel Lateral Field Excited Acoustic Wave Sensor For Chemical And Biological Agents, John F. Vetelino, David Frankel, Carl Tripp, Paul J. Millard

University of Maine Office of Research Administration: Grant Reports

Sensors for the sensitive and selective detection of chemical agents and a biological agent are being developed. The sensor structure consists of a piezoelectric platform that is coated with a film that selectively sorbs a chemical or biological agent of interest. The sensitivity of the sensor is embodied in the sensor platform, which consists of a quartz crystal that is excited by a lateral electric field. The exciting electrodes are placed opposite to the sensing surface, and the sensing film is attached directly to the sensor platform. This arrangement is in contrast to the standard quartz microbalance (QCM), where the …

A Thermally Wavelength-Tunable Photonic Switch Based On Silicon Microring Resonator, Xuan Wang

FIU Electronic Theses and Dissertations

Silicon photonics is a very promising technology for future low-cost high-bandwidth optical telecommunication applications down to the chip level. This is due to the high degree of integration, high optical bandwidth and large speed coupled with the development of a wide range of integrated optical functions. Silicon-based microring resonators are a key building block that can be used to realize many optical functions such as switching, multiplexing, demultiplaxing and detection of optical wave. The ability to tune the resonances of the microring resonators is highly desirable in many of their applications. In this work, the study and application of a …

Rigid And Non-Rigid Point-Based Medical Image Registration, Nestor Andres Parra

FIU Electronic Theses and Dissertations

The primary goal of this dissertation is to develop point-based rigid and non-rigid image registration methods that have better accuracy than existing methods. We first present point-based PoIRe, which provides the framework for point-based global rigid registrations. It allows a choice of different search strategies including (a) branch-and-bound, (b) probabilistic hill-climbing, and (c) a novel hybrid method that takes advantage of the best characteristics of the other two methods. We use a robust similarity measure that is insensitive to noise, which is often introduced during feature extraction. We show the robustness of PoIRe using it to register images obtained with …

Effective Reconfigurable Antenna Designs To Enhance Performance And Enable Wireless Powering, Shishir S. Punjala

FIU Electronic Theses and Dissertations

With the increase in traffic on the internet, there is a greater demand for wireless mobile and ubiquitous applications. These applications need antennas that are not only broadband, but can also work in different frequency spectrums. Even though there is a greater demand for such applications, it is still imperative to conserve power. Thus, there is a need to design multi-broadband antennas that do not use a lot of power. Reconfigurable antennas can work in different frequency spectrums as well as conserve power. The current designs of reconfigurable antennas work only in one band. There is a need to design …

Computer-Aided Assessment Of Diagnostic Images For Epidemiological Research, Alison G. Abraham, Donald D. Duncan, Stephen J. Gange, Sheila West

Electrical and Computer Engineering Faculty Publications and Presentations

Background: Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD) algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research. Methods: Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and …

A Framework For Bioacoustic Vocalization Analysis Using Hidden Markov Models, Yao Ren, Michael T. Johnson, Patrick J. Clemins, Michael Darre, Sharon Stuart Glaeser, Tomasz S. Osiejuk, Ebenezer Out-Nyarko

Electrical and Computer Engineering Faculty Research and Publications

Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of …

Analysis And Diagnostics Of Adjacent And Nonadjacent Broken-Rotor-Bar Faults In Squirrel-Cage Induction Machines, Gennadi Y. Sizov, Ahmed Mohamed Sayed Ahmed, Chia-Chou Yeh, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In this paper, faults associated with the rotor of an induction machine are considered. More specifically, effects of adjacent and nonadjacent bar breakages on rotor fault diagnostics in squirrel-cage induction machines are studied. It is shown that some nonadjacent bar breakages may result in the masking of the commonly used fault indices and, hence, may lead to a possible misdiagnosis of the machine. A discussion of the possible scenarios of these breakages as well as some conclusions regarding the types of squirrel-cage induction machines (number of poles, number of squirrel-cage bars, etc.) that may be more prone to these nonadjacent …

Demonstration Of A Bias Tunable Quantum Dots-In-A-Well Focal Plane Array, Jonathan Andrews, Woo-Yong Jang, Jorge E. Pezoa, Yagya D. Sharma, Sang Jun Lee, Sam Kyu Noh, Majeed M. Hayat, Sergio Restaino, Scott W. Teare, Sanjay Krishna

Electrical and Computer Engineering Faculty Research and Publications

Infrared detectors based on quantum wells and quantum dots have attracted a lot of attention in the past few years. Our previous research has reported on the development of the first generation of quantum dots-in-a-well (DWELL) focal plane arrays, which are based on InAs quantum dots embedded in an InGaAs well having GaAs barriers. This focal plane array has successfully generated a two-color imagery in the mid-wave infrared (i.e. 3–5 μm) and the long-wave infrared (i.e. 8–12 μm) at a fixed bias voltage. Recently, the DWELL device has been further modified by embedding InAs quantum dots in InGaAs …

Meshscan: Performance Of Passive Handoff And Active Handoff, Yin Chen, Karol Kowalik, Mark Davis

Conference papers

A core problem of fast handoff is when handoff should perform and which Mesh Node (MN) should associated with. We have developed a fast handoff management scheme called MeshScan to provide a novel use of channel scanning latency, by employing open system authentication in both Passive Handoff and Active Handoff. This scheme comprises three steps: firstly a client device takes advantage of the Wireless Mesh Network (WMN) architecture to maintain a list of active MNs. Secondly MeshScan Handoff Sensor performs handoff when it receives a disassociation management frame from the serving MN or when the measured signal strength from the …