Engineering Commons^™

Coordinated Control And Estimation Of Multiagent Systems With Engineering Applications, Housheng Su, Michael Z.Q. Chen, Qing Hui, Wei Zhang, Fanglai Zhu

Department of Electrical and Computer Engineering: Faculty Publications

Recently, coordinated control and estimation problems have attracted a great deal of attention in different fields especially in biology, physics, computer science, and control engineering. Coordinated control and estimation problems have prominent characteristics of distributed control, local interaction, and self-organization. Research on multiagent coordinated control and estimation problems not only helps better understand the mechanisms of natural collective phenomena but also benefits the applications of cyberphysical systems.

This special issue focuses on theoretical and technological achievements in cooperative multiagent Systems. It contains twenty-six papers, the contents of which are summarized below.

A Study On Resource Efficient Digital Multimedia Security Measures In Mobile Devices, Prabhat Dahal

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

Advanced image and video processing abilities in smart phones and digital cameras make them popular means to capture multimedia. In addition, the integration of internet into such devices users seek to capture and easily share multimedia right from their smartphone while most steganography techniques are computer based. Hence, it is of utmost importance that the multimedia be processed for steganography right within the devices for multimedia authentication.

In this thesis, we first implement steganography into mobile smart devices that can capture multimedia. For devices such as smart phones, we propose a method to hide payload bits within video frames. The …

Application Of Femtosecond Laser Surface Processed Electrodes In Electrolysis Of Water, Christopher K. Wilson

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

Femtosecond laser surface processing (FLSP) is a machining technique used to develop functionalized surfaces consisting of micro and nano-scale features. Metal electrodes processed using this technique can be used in water electrolysis to facilitate more efficient hydrogen and oxygen gas production. This thesis explores the electrochemical behavior of femtosecond laser processed 316SS electrodes in water electrolysis. The multi-scale surface structure size and separation were controlled through laser fluence and incident laser pulse count. The electrodes were studied in a three electrode electrolysis cell containing a 3M KOH(aq) electrolyte, FLSP 316SS working electrode, 316SS counter electrode, and Hg/HgO reference electrode. Through …

Low-Power Analog Processing, Daniel J. White

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

This dissertation presents the analog harmonic transform (AHT) and a first implementation in an integrated circuit. The transform is designed for a regular and simple hardware structure. It provides coefficients relating to an input signal's spectrum. These coefficients also have a simple relationship to the signal's Fouri\'er series coefficients.

The AHT is defined in its ideal form and evaluated for two example signal classification applications. Both military vehicle and bearing fault classification tasks are presented which validate the ability of a neural network to use the AHT coefficients to correctly classify the input signals. Because any real use of the …

Stable And Metastable Nanowires Displaying Locally Controllable Properties, Eli A. Sutter, Peter Werner Sutter

Department of Electrical and Computer Engineering: Faculty Publications

(57) ABSTRACT Vapor-liquid-solid growth of nanowires is tailored to achieve complex one-dimensional material geometries using phase diagrams determined for nanoscale materials. Segmented one-dimensional nanowires having constant composition dis play locally variable electronic band structures that are deter mined by the diameter of the nanowires. The unique electrical and optical properties of the segmented nanowires are exploited to form electronic and optoelectronic devices. Using gold-germanium as a model system, in situ transmis sion electron microscopy establishes, for nanometer-sized Au Ge alloy drops at the tips of Ge nanowires (NWs), the parts of the phase diagram that determine their temperature dependent equilibrium …

A Low-Power Compact Nuclear Quadrupole Resonance (Nqr) Based Explosive Detection System, Xinwang Zhang

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

Abandoned landmines and terrorist bomb attacks are severe issues threatening our society. These issues necessitate the development of prompt and accurate explosive detection systems. The detection mechanisms commonly-used nowadays usually search for explosive containers, which suffer numerous false alarms caused by external detection circumstance changes. Alternatively, explosive substances inside the bombs and landmines can be detected by means of biology, chemistry and physics techniques. Nuclear Quadrupole Resonance (NQR) detection technology has proven to be a highly effective solution for detecting explosives unambiguously.

In this work, a portable NQR-based explosive detection system that employs state-of-the-art semiconductor technologies is presented. This system …

Designing A Bayer Filter With Smooth Hue Transition Interpolation Using The Xilinx System Generator, Zhiqiang Li, Peter Revesz

CSE Conference and Workshop Papers

This paper describes the design of a Bayer filter with smooth hue transition using the System Generator for DSP. We describe and compare experimentally two different designs, one based on a MATLAB implementation and the other based on a modification of the Bayer filter using bilinear interpolation.

A Game-Theoretic Analysis Of The Nuclear Non-Proliferation Treaty, Peter Revesz

CSE Conference and Workshop Papers

Although nuclear non-proliferation is an almost universal human desire, in practice, the negotiated treaties appear unable to prevent the steady growth of the number of states that have nuclear weapons. We propose a computational model for understanding the complex issues behind nuclear arms negotiations, the motivations of various states to enter a nuclear weapons program and the ways to diffuse crisis situations.

Estimating The Flight Path Of Moving Objects Based On Acceleration Data, Peter Revesz

CSE Conference and Workshop Papers

Inertial navigation is the problem of estimating the flight path of a moving object based on only acceleration measurements. This paper describes and compares two approaches for inertial navigation. Both approaches estimate the flight path of the moving object using cubic spline interpolation, but they find the coefficients of the cubic spline pieces by different methods. The first approach uses a tridiagonal matrix, while the second approach uses recurrence equations. They also require different boundary conditions. While both approaches work in O(n) time where n is the number of given acceleration measurements, the recurrence equation-based method can be easier updated …

Cubic Spline Interpolation By Solving A Recurrence Equation Instead Of A Tridiagonal Matrix, Peter Revesz

CSE Conference and Workshop Papers

The cubic spline interpolation method is proba- bly the most widely-used polynomial interpolation method for functions of one variable. However, the cubic spline method requires solving a tridiagonal matrix-vector equation with an O(n) computational time complexity where n is the number of data measurements. Even an O(n) time complexity may be too much in some time-ciritical applications, such as continuously estimating and updating the flight paths of moving objects. This paper shows that under certain boundary conditions the tridiagonal matrix solving step of the cubic spline method could be entirely eliminated and instead the coefficients of the unknown cubic polynomials …

Uv Laser-Assisted Diamond Deposition, Mengxiao Wang

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

Diamond, due to its unique properties, has been studied for decades. Many diamond synthesis methods have been developed as well. As one of the synthesis methods, combustion flame chemical vapor deposition (CVD) is considered as the most flexible way. Combined with laser irradiation, laser-assisted combustion flame CVD can enhance the deposition process of diamond films. In this thesis work, efforts were made to explore the capability of a laser-assisted combustion flame CVD technique with krypton fluoride (KrF) excimer laser irradiation for improving diamond thin film quality and deposition rate. The research efforts mainly focus on following activities, including: 1) studying …

Towards Highly-Integrated Stereovideoscopy For In Vivo Surgical Robots, Jay Carlson

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

When compared to traditional surgery, laparoscopic procedures result in better patient outcomes: shorter recovery, reduced post-operative pain, and less trauma to incisioned tissue. Unfortunately, laparoscopic procedures require specialized training for surgeons, as these minimally-invasive procedures provide an operating environment that has limited dexterity and limited vision. Advanced surgical robotics platforms can make minimally-invasive techniques safer and easier for the surgeon to complete successfully. The most common type of surgical robotics platforms -- the laparoscopic robots -- accomplish this with multi-degree-of-freedom manipulators that are capable of a diversified set of movements when compared to traditional laparoscopic instruments. Also, these laparoscopic robots …

Expected Cost Penalty Due To Deviation From Security-Constrained Dispatch, Veravut Dheraprasart

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

This thesis introduces and evaluates a new index called ”Expected Cost Penalty Due to Deviation From Security Constrained Dispatch” (ECP_SCD) for interconnected power systems planning. This index represents the optimal operating cost of the system taking into account the uncertainties such as random failure of generating units, transformer, and transmission lines in interconnected power systems. The significance of this index is that it represents the minimum operating cost for a contingency event and can be used for contingency screening (ranking). This index also indicates the impact of equipment reliability on the average cost penalty of all contingency events. Moreover, this …

Characterization And Testing Of A 5.8 Kv Sic Pin Diode For Electric Space Propulsion Applications, Alexandra Toftul

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

Inductive Pulsed Plasma Thrusters (IPPTs) are a type of in-space propulsion that has multiple advantages over conventional chemical propulsion for long-duration, deep space missions. Existing IPPT prototypes utilize spark gap switches, however these are subject to corrosion problems that make them unreliable for long-term use. Recent advances in solid state switching technology have opened up a variety of switching options that could provide greater reliability, controllability, and increased energy efficiency. Taking advantage of this, a novel thruster drive circuit topology containing a high-power silicon controlled rectifier (SCR) and series fast recovery diode (FRD) is proposed that is expected to increase …

Performance Analysis Of Mobile Ad-Hoc Routing Protocols By Varying Mobility, Speed And Network Load, Nilotpal Sarmah

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

One of the most promising network that has emerged from the technology world is the mobile ad-hoc network or MANET. It is a type of multi-hop network. Wireless by nature, MANETs do not have a specific network infrastructure. It is a collection of wireless mobile devices that communicate with each other without the help of any third party backbone like a base-station or a router. It can be hard to imagine how every node in this type of network communicate with one another without having a router. In MANETs, nodes change locations with time, configure themselves and get the information …

Growth Of Graphene Films And Graphene Patterns, Yongfeng Lu, Wei Xiong, Yunshen Zhou

Department of Electrical and Computer Engineering: Faculty Publications

Large area graphene can be fabricated by depositing carbon and catalytic metal thin film(s) on a substrate, heating the carbon and the catalytic metal, and forming graphene on the substrate. The catalytic metal is evaporated during the heating process. The catalytic metal can be, for example, nickel, cobalt, or iron.

Thickness Determination Of Few-Layer Hexagonal Boron Nitride Films By Scanning Electron Microscopy And Auger Electron Spectroscopy, P. Sutter, E. Sutter

Department of Electrical and Computer Engineering: Faculty Publications

We assess scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) for thickness measurements on few-layer hexagonal boron nitride (h-BN), the layered dielectric of choice for integration with graphene and other two-dimensional materials. Observations on h-BN islands with large, atomically flat terraces show that the secondary electron intensity in SEM reflects monolayer height changes in films up to least 10 atomic layers thickness. From a quantitative analysis of AES data, the energy-dependent electron escape depth in h-BN films is deduced. The results show that AES is suitable for absolute thickness measurements of few-layer h-BN of 1 to 6 layers.

Self-Organizing Microstructures Orientation Control In Femtosecond Laser Patterning On Silicon Surface, Pengjun Liu, Lan Jiang, Jie Hu, Shuai Zhang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Self-organizing rippled microstructures are induced on silicon surface by linearly polarized femtosecond laser pulses. At a near threshold fluence, it is observed that ripple orientation is co-determined by the laser polarization direction and laser scanning parameters (scanning direction and scanning speed) in surface patterning process. Under fixed laser polarization, the ripple orientation can be controlled to rotate by about 40° through changing laser scanning parameters. In addition, it is also observed that the ripple morphology is sensitive to the laser scanning direction, and it is an optimal choice to obtain ordered ripple structures when the angle between laser scanning and …

Human Brain Networks: Spiking Neuron Models, Multistability, Synchronization, Thermodynamics, Maximum Entropy Production, And Anesthetic Cascade Mechanisms, Wassim H. Haddad, Qing Hui, James M. Bailey

Department of Electrical and Computer Engineering: Faculty Publications

Advances in neuroscience have been closely linked to mathematical modeling beginning with the integrate-and-fire model of Lapicque and proceeding through the modeling of the action potential by Hodgkin and Huxley to the current era. The fundamental building block of the central nervous system, the neuron, may be thought of as a dynamic element that is “excitable”, and can generate a pulse or spike whenever the electrochemical potential across the cell membrane of the neuron exceeds a threshold. A key application of nonlinear dynamical systems theory to the neurosciences is to study phenomena of the central nervous system that exhibit nearly …

Anisotropy Modulations Of Femtosecond Laser Pulse Induced Periodic Surface Structures On Silicon By Adjusting Double Pulse Delay, Weina Han, Lan Jiang, Xiaowei Li, Qingsong Wang, Hao Li, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

We demonstrate that the polarization-dependent anisotropy of the laser-induced periodic surface structure (LIPSS) on silicon can be adjusted by designing a femtosecond laser pulse train (800 nm, 50 fs, 1 kHz). By varying the pulse delay from 100 to 1600 fs within a double pulse train to reduce the deposited pulse energy, which weakens the directional surface plasmon polarition (SPP)-laser energy coupling based on the initial formed ripple structure, the polarization-dependent geometrical morphology of the LIPSS evolves from a nearly isotropic circular shape to a somewhat elongated elliptical shape. Meanwhile, the controllable anisotropy of the two-dimensional scanned-line widths with different …

Preliminary Test Of A Real-Time, Interactive Silent Speech Interface Based On Electromagnetic Articulograph, Jun Wang, Ashok Samal, Jordan R. Green

CSE Conference and Workshop Papers

A silent speech interface (SSI) maps articulatory movement data to speech output. Although still in experimental stages, silent speech interfaces hold significant potential for facilitating oral communication in persons after laryngectomy or with other severe voice impairments. Despite the recent efforts on silent speech recognition algorithm development using offline data analysis, online test of SSIs have rarely been conducted. In this paper, we present a preliminary, online test of a real-time, interactive SSI based on electromagnetic motion tracking. The SSI played back synthesized speech sounds in response to the user’s tongue and lip movements. Three English talkers participated in this …

Processing Of Monolayer Materals Vlanterfacial Reactions, Peter Werner Sutter, Eli Anguelova Sutter

Department of Electrical and Computer Engineering: Faculty Publications

A method of forming and processing of graphene is disclosed based on exposure and selective intercalation of the partially graphene-covered metal Substrate with atomic or molecular intercalation species such as oxygen (O) and nitrogen oxide (NO). The process of intercalation lifts the strong metal carbon coupling and restores the characteristic Dirac behav ior of isolated monolayer graphene. The interface of graphene with metals or metal-decorated substrates also provides for controlled chemical reactions based on novel functionality of the confined space between a metal Surface and a graphene sheet.

Theoretical Modeling Of Laser-Induced Absorption Phenomena In Optical Materials, Chris Ferris

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

For over five decades, laser-induced damage and breakdown in optical materials has been an active field of research. As laser systems continually advance, new opportunities to study laser/material interactions arise. This thesis begins by presenting the damage mechanisms and absorption phenomena that lead to laser-induced breakdown. An in depth understanding of these processes led to the development of rate equations that describe electron density growth in a material exposed to a strong electromagnetic wave. These rate equations laid the foundation for the construction of a theoretical model. By using variable laser and material parameter inputs, the model calculates the laser-induced …

Security Analysis Of Phasor Measurement Units In Smart Grid Communication Infrastructures

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

Phasor Measurement Units (PMUs), or synchrophasors, are rapidly being deployed in the smart grid with the goal of measuring phasor quantities concurrently from wide area distribution substations. By utilizing GPS receivers, PMUs can take a wide area snapshot of power systems. Thus, the possibility of blackouts in the smart grid, the next generation power grid, will be reduced. As the main enabler of Wide Area Measurement Systems (WAMS), PMUs transmit measured values to Phasor Data Concentrators (PDCs) by the synchrophasor standard IEEE C37.118. IEC 61850 and IEC 62351 are the communication protocols for the substation automation system and the security …

Polarization-Coupled Ferroelectric Unpolarunction Memory And Energy Storage Device, Mathias M. Schubert, Tino Hofmann, Venkata Rao Voora

Department of Electrical and Computer Engineering: Faculty Publications

A memory device is provided. The memory device includes a plurality of memory cells and a controller to write data to and read data from the memory cells. Each memory cell includes a first semiconductor material having a spontaneous polarization, a resistive ferroelectric material having a switchable spontaneous polarization, and a second semiconductor material having a spontaneous polarization, the resistive ferroelectric material being positioned between and in contact with the first and second semiconductor materials. The memory device can be configured to store energy that can be released by applying a voltage pulse to the memory device.

Flame-Enhanced Laser-Induced Breakdown Spectroscopy, L. Liu, S. Li, X. N. He, X. Huang, C. F. Zhang, L. S. Fan, M. X. Wang, Y. S. Zhou, K. Chen, L. Jiang, J. F. Silvain, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Flame-enhanced laser-induced breakdown spectroscopy (LIBS) was investigated to improve the sensitivity of LIBS. It was realized by generating laser-induced plasmas in the blue outer envelope of a neutral oxy-acetylene flame. Fast imaging and temporally resolved spectroscopy of the plasmas were carried out. Enhanced intensity of up to 4 times and narrowed full width at half maximum (FWHM) down to 60% for emission lines were observed. Electron temperatures and densities were calculated to investigate the flame effects on plasma evolution. These calculated electron temperatures and densities showed that high-temperature and low-density plasmas were achieved before 4 μs in the flame environment, …

Relationship Between Photofixed Condensate, Effluent And Bulk Composition Of Several Common Rtv Materials, Fen Zhou Hanrahan, Natale J. Ianno

Department of Electrical and Computer Engineering: Faculty Publications

Raman spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy are employed to analyze the bulk compositions of five kinds of Room Temperature Vulcanized (RTV) silicones (CV2568, RTV566, DC93-500, SCV2590 and SCV2590-2) that are commonly employed in orbiting spacecraft. It is found that polydimethylsiloxane (PDMS), silicon dioxide, Tetra-n-propylsilicate (NPS), silicic acid, tetraethyl orthosilicate, and trimethylsilanol are contained in all of them. The outgassing products from those silicones are characterized by FTIR. By comparing the position of the peaks, it is found that the outgassing products of each material are PDMS and NPS which are consistent with the compositions of samples determined with …

Position/Speed Sensorless Control For Permanent-Magnet Synchronous Machines, Yue Zhao

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

Permanent-magnet synchronous machines (PMSMs) are widely used in industrial applications owing to their distinctive advantages, such as high efficiency, high power density, and wide constant power region. To achieve high-performance field oriented control, accurate rotor position information, which is usually measured by rotary encoders or resolvers, is indispensable. However, the use of these sensors increases the cost, size, weight, and wiring complexity and reduces the mechanical robustness and the reliability of the overall PMSM drive systems. The goal of the research for this dissertation was to develop a rotor position/speed sensorless control system with performance comparable to the sensor-based control …

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.

An Effective Heat Propagation Path-Based Online Adaptive Thermal Model For Igbt Modules, Ze Wang, Wei Qiao, Bo Tian, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The information of junction temperature is crucial for operation management of IGBT modules. In practice, junction temperature is typically estimated by using an electrothermal model. IGBT modules are subject to various aging processes during operation, some of which, e.g. substrate solder crack, changes the thermal impedance of an IGBT module. However, in the literature little work has included the aging effects into online thermal behavior modeling of IGBT modules. This paper proposes an Effective Heat Propagation Path (EHPP)-based online adaptive thermal model for IGBT modules, where the EHPP is proposed to quantify the impact of substrate solder cracks on the …