Electrical and Computer Engineering Commons^™

A Security Protocol For Advanced Metering Infrastructure In Smart Grid, Feng Ye, Yi Qian, Rose Qingyang Hu

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we propose a security protocol for advanced metering infrastructure (AMI) in smart grid. AMI is one of the important components in smart grid and it suffers from various vulnerabilities due to its uniqueness compared with wired networks and traditional wireless mesh networks. Our proposed security protocol for AMI includes initial authentication, secure uplink data aggregation/recovery, and secure downlink data transmission. Compared with existing researches in such area, our proposed security protocol let the customers be treated fairly, the privacy of customers be protected, and the control messages from the service provider be delivered safely and timely.

Free Space Optical Data Center Architecture Design With Fully Connected Racks, Abdelbaset S. Hamza, Jitender S. Deogun, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we propose a novel design of a data center (DC) using free space optical (FSO) technology. The proposed FSO-DC design is based on fixed, non-mechanical, FSO links facilitating the realization of fully connected FSO racks and rows/columns of racks. Each rack becomes a point of intersection of three fully connected sub-networks. We investigate requirements, advantages and challenges of the proposed design. We develop and analyze a switch-free, fully connected FSO rack, present its link budget analysis and validate it by simulation. Results establish the feasibility of a switch-free FSO rack based on the proposed FSO-DC design. A …

Enhanced Pool-Boiling Heat Transfer And Critical Heat Flux Using Femtosecond Laser Surface Processing, Corey M. Kruse, Troy P. Anderson, Chris Wilson, Craig A. Zuhlke, Dennis R. Alexander, George Gogos, Sidy Ndao

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we present the experimental investigation of pool boiling heat transfer on multiscale (micro/nano) functionalized metallic surfaces. The multiscale structures were fabricated via a femtosecond laser surface process (FLSP) technique which forms mound-like microstructures covered by layers of nanoparticles. Using a pool boiling experimental setup with deionized water as the working fluid, both the heat transfer coefficient and critical heat flux were investigated. The polished reference sample was found to have a critical heat flux of 91 W/cm² at 40 °C of superheat and a maximum heat transfer coefficient of 23,000 W/m²-K. The processed sample …

Fault Diagnosis For Drivetrain Gearboxes Using Pso-Optimized Multiclass Svm Classifier, Dingguo Lu, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

A novel method consisting of an adaptive feature extraction scheme and a particle swarm optimization (PSO)- optimized multiclass support vector machine (SVM) classifier is proposed for condition monitoring and fault diagnosis of drivetrain gearboxes in variable-speed operational conditions. The adaptive feature extraction scheme consists of an adaptive signal resampling algorithm, a frequency tracker, and a feature generation algorithm for effective extraction of the features of gearbox faults from the stator current signal of the AC electric machine connected to the gearbox. The multiclass SVM classifier is designed to identify different faults in the gearbox according to the fault features extracted. …

Characterizing The Rf Performance Of The Ez430-Chronos Wrist Watch, Francisco J. Mora-Becerra, Pedro Sathler, Jay D. Carlson, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

The Texas Instruments eZ430-Chronos development kit is a popular wireless platform for researchers, commercial developers, and hobbyists. Built into the form factor of a standard wrist watch, the Chronos is ideal for wireless body area networks (WBANs), indoor localization, and activity detection. Many of these applications requires knowledge of the RF performance of the platform, which has never been characterized by Texas Instruments nor any third parties. Here, we provide experimental data characterizing the RF performance of the eZ430-Chronos watch in various configurations, including when worn by a person while sitting, standing, and reaching. The RF performance of the Chronos …

Steganography Attack Based On Discrete Spring Transform And Image Geometrization, Qilin Qi, Aaron Sharp, Yaoqing Lamar Yang, Dongming Peng, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

In order to prevent harmful secret information sharing by steganography, a new active-warden countermeasure approach against steganography is proposed in this paper. Differently from the other countermeasure approaches presented in current literature which need to have some knowledge of the steganographic algorithms to be attacked, our proposed method is a generic method which is independent of any particular steganography methods being utilized. In other words, our approach blindly attacks the steganography without any prior knowledge of the used algorithms or their existence. In general, the hidden information is embedded in a carrier by adjusting the coefficients of the audio or …

Study On Case Temperature Distribution For Condition Monitoring Of Multidie Igbt Modules, Bo Tian, Ze Wang, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

The parasitic and proximity effects in multidie insulated-gate bipolar transistor (IGBT) modules lead to nonuniform distributions of junction temperature (T_J) and case temperature (T_C) among different dies. This feature can be used to monitor the operating and health condition of multidie IGBT modules. This paper reports a comprehensive study on the distribution of T_C and its influence on T_J estimation using a thermal network model for a multidie IGBT module before and after aging. Specifically, experimental studies using accelerated aging tests are conducted for a 9-die IGBT module. Results demonstrate that the …

Modeling Molecular Communications At Nano-Scale With Applications In Medicine And Microbiology, Tadeusz A. Wysocki

Department of Electrical and Computer Engineering: Faculty Publications

No abstract provided.

An Isolated Multiport Bidirectional Dc-Dc Converter For Pv-Battery-Dc Microgrid Applications, Jianwu Zeng, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a new isolated, multiport, bidirectional DC-DC converter with the least number of switches for photovoltaic (PV)-battery-DC microgrid applications. The proposed converter is able to perform the maximum power point tracking (MPPT) control for the PV system when solar energy is available as well as control the charge and discharge of the battery with the PV system and the DC microgrid. Simulation and experimental studies are carried out and validate the proposed converter for simultaneous power management of a PV-battery system connected to a DC microgrid.

A Low-Power Compact Nqr Based Explosive Detection System, Xinwang Zhang, Nathan Schemm, Sina Balkır, Michael W. Hoffman

Department of Electrical and Computer Engineering: Faculty Publications

Nuclear quadruple resonance (NQR) has been studied for explosive detection for years. Some prototype NQR-based detection systems have been reported, but were all designed from the laboratory perspective, with bulky sizes and high power consumption. To achieve a portable NQR-based detection system for field applications, a low-power compact system utilizing state-of-the-art semiconductor technologies is presented in this paper. Several novel circuits for the key modules are proposed, including a Class-D type power amplifier, a power multiplexing and matching network, a customized IC with integrated analog signal processing chain, and a microcontroller-based logic control unit. An advanced digital signal processor platform …

A Sliding-Mode Duty-Ratio Controller For Dc/Dc Buck Converters With Constant Power Loads, Yue Zhao, Wei Qiao, Daihyun Ha

Department of Electrical and Computer Engineering: Faculty Publications

Incorporating a medium-voltage dc (MVDC) integrated power system is a goal for future surface combatants and submarines. In an MVDC shipboard power system, dc/dc converters are commonly employed to supply constant power to electric loads. These constant power loads have a characteristic of negative incremental impedance, which may cause system instability during disturbances if the system is not properly controlled. This paper proposes a sliding-mode duty-ratio controller (SMDC) for dc/dc buck converters with constant power loads. The proposed SMDC is able to stabilize the dc power systems over the entire operating range in the presence of significant variations in the …

A Comparison Between Uwb And Tdoa Systems For Smart Space Localization, Lianlin Zhao, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

A comparison between two different systems for smart space localization is presented. A smart space implemented at the University of Nebraska-Lincoln was designed for automated and intelligent assistance for elderly and disabled people, and also for astronauts in space. Localization is a critical component of the smart space since it provides the system with the movement patterns and location of its inhabitants. Two systems have been deployed and evaluated for the purpose of localizing people in the smart space: the Ubisense ultra-wide band (UWB) system and the Cricket indoor localization system. Both systems support three-dimensional localization within the smart space. …

Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata Wysocki, Timothy M. Martin, Tadeusz A. Wysocki, Angela K. Pannier

Department of Electrical and Computer Engineering: Faculty Publications

Communications, in general, involve delivery of information from a source to a sink. At nano-scale, an example of a man-made communications involving interfacing with biological systems at intra-cellular level is non-viral gene delivery. From a telecommunications engineering perspective, important end-to-end parameters of such a system are: the endto- end delay, system capacity, and packet loss rate. There are neither known methods to estimate those parameters theoretically nor they are ready available from standard measurements. The paper provides estimates for those parameters based on the simulation of non-viral gene delivery system based on the queuing theory. The simulator used has bee

Whole Genome Sequence Of A Turkish Individual, Haluk Dogan, Handan Can, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Although whole human genome sequencing can be done with readily available technical and financial resources, the need for detailed analyses of genomes of certain populations still exists. Here we present, for the first time, sequencing and analysis of a Turkish human genome. We have performed 35x coverage using paired-end sequencing, where over 95% of sequencing reads are mapped to the reference genome covering more than 99% of the bases. The assembly of unmapped reads rendered 11,654 contigs, 2,168 of which did not reveal any homology to known sequences, resulting in,1 Mbp of unmapped sequence. Single nucleotide polymorphism (SNP) discovery resulted …

Terahertz-Infrared Ellipsometer System, And Method Of Use, Craig H. Herzinger, Mathias M. Schubert, Tino Hofmann, Martin M. Liphardt, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up Sh and his th. 100 THz, including: a Source Such as a backward wave oscillator, a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and a detector Such as a Golay cell; abolometer or a solid state detector: and preferably including a polarization …

Comparison Of Magnetic Probe Calibration At Nano And Millitesla Magnitudes, Ryan A. Pahl, Joshua L. Rovey, David Pommerenke

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of Ḃ probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work …

Conae Microwave Radiometer (Mwr) Counts To Brightness Temperature Algorithm, Zoubair Ghazi

Electronic Theses and Dissertations

This dissertation concerns the development of the MicroWave Radiometer (MWR) brightness temperature (Tb) algorithm and the associated algorithm validation using on-orbit MWR Tb measurements. This research is sponsored by the NASA Earth Sciences Aquarius Mission, a joint international science mission, between NASA and the Argentine Space Agency (Comision Nacional de Actividades Espaciales, CONAE). The MWR is a CONAE developed passive microwave instrument operating at 23.8 GHz (K-band) H-pol and 36.5 GHz (Ka-band) H- and V-pol designed to complement the Aquarius L-band radiometer/scatterometer, which is the prime sensor for measuring sea surface salinity (SSS). MWR measures the Earth's brightness temperature and …

High Resolution Time-Resolved Imaging System In The Vacuum Ultraviolet Region, Yuseong Jang

Electronic Theses and Dissertations

High-power debris-free vacuum ultraviolet (VUV) light sources have applications in several scientific and engineering areas, such as high volume manufacturing lithography and inspection tools in the semiconductor industry, as well as other applications in material processing and photochemistry. For the past decades, the semiconductor industry has been driven by what is called "Moore's Law". The entire semiconductor industry relies on this rule, which requires chip makers to pack transistors more tightly with every new generation of chips, shrinking the size of transistors. The ability to solve roadmap challenges is, at least partly, proportional to our ability to measure them. The …

Practical Implementations Of The Active Set Method For Support Vector Machine Training With Semi-Definite Kernels, Christopher Sentelle

Electronic Theses and Dissertations

The Support Vector Machine (SVM) is a popular binary classification model due to its superior generalization performance, relative ease-of-use, and applicability of kernel methods. SVM training entails solving an associated quadratic programming (QP) that presents significant challenges in terms of speed and memory constraints for very large datasets; therefore, research on numerical optimization techniques tailored to SVM training is vast. Slow training times are especially of concern when one considers that re-training is often necessary at several values of the models regularization parameter, C, as well as associated kernel parameters. The active set method is suitable for solving SVM problem …

Transparent Oxide Semiconductor Gate Based Mosfets For Sensor Applications, Ashwin Kumar Saikumar

Electronic Theses and Dissertations

Starting from small scale laboratories to the highly sophisticated industrial facilities, monitoring and control forms the most integral part. In order to perform this continuous monitoring we require an interface, that would operate between the system and its processing conditions and in turn which facilitates us to act accordingly. This interface is called as a sensor. There are various types of sensors available which have wide range of functionality in various different fields. The use of transparent conducting oxide (TCO) in the field of sensor applications has increased and has been the subject of extensive research. Good electrical properties, good …

Array Of Surface-Confined Glow Discharges In Atmospheric Pressure Helium: Modes And Dynamics, D. Li, D. X. Liu, Q. Y. Nie, H. P. Li, H. L. Chen, M. G. Kong

Bioelectrics Publications

Array of atmospheric pressure surface discharges confined by a two-dimensional hexagon electrode mesh is studied for its discharge modes and temporal evolution so as to a theoretical underpinning to their growing applications in medicine, aerodynamic control, and environmental remediation. Helium plasma surface-confined by one hexagon-shaped rim electrode is shown to evolve from a Townsend mode to a normal and abnormal glow mode, and its evolution develops from the rim electrodes as six individual microdischarges merging in the middle of the hexagon mesh element. Within one hexagon element, microdischarges remain largely static with the mesh electrode being the instantaneous cathode, but …

Detection Of Seagrass Scars Using Sparse Coding And Morphological Filter, Ender Oguslu, Sertan Erkanli, Victoria J. Hill, W. Paul Bissett, Richard C. Zimmerman, Jiang Li, Charles R. Bostater Jr. (Ed.), Stelios P. Mertikas (Ed.), Xavier Neyt (Ed.)

OES Faculty Publications

We present a two-step algorithm for the detection of seafloor propeller seagrass scars in shallow water using panchromatic images. The first step is to classify image pixels into scar and non-scar categories based on a sparse coding algorithm. The first step produces an initial scar map in which false positive scar pixels may be present. In the second step, local orientation of each detected scar pixel is computed using the morphological directional profile, which is defined as outputs of a directional filter with a varying orientation parameter. The profile is then utilized to eliminate false positives and generate the final …

A Probabilistic Technique For Open Set Recognition Using Support Vector Machines, Matthew Scherreik

Browse all Theses and Dissertations

Classification algorithms trained using finite sets of target and confuser data are limited by the training set. These algorithms are trained under closed set assumptions and do not account for the infinite universe of confusers found in practice. In contrast, classification algorithms developed under open set assumptions label inputs not present in the training data as unknown instead of assigning the most likely class. We present an approach to open set recognition, the probabilistic open set SVM, that utilizes class posterior estimates to determine probability thresholds for classification. This is accomplished by first training an SVM in a 1-vs-all configuration …

Hierarchical Modulation Detection Of Underwater Acoustic Communication Signals Through Maximum Likelihood Combining, Josh Sanderson

Browse all Theses and Dissertations

Modulation detection is important to many communication applications. Much research has been done in this area for radio frequency (RF) signals, but until recently little has carried over to the underwater communication world. Traditional methods include the use of fourth order cumulants or second order cyclostationary features to determine the modulation scheme being used. Many of these methods fail due to the complex and varying nature of the underwater channel. This thesis proposes a new form of hierarchy modulation detection for underwater acoustic communication signals using maximum likelihood combining. The proposed method for hierarchical modulation detection for this research is …

Java Implementation Of Grounded Circumscription For Owl, Ali Akhavan Karbasi

Browse all Theses and Dissertations

The semantic web is a new development in the World Wide Web (WWW) supporting machine-readable and machine-understandable data in order to add the "understanding" aspect to current capabilities. This technology involves the use of semantic reasoners, which are software that can infer logical consequences from a set of facts or axioms. Inference can be done in different ways, e.g. based on what is called the open world assumption in which what is not known to be true is simply unknown, and its closed world assumption opposite, which considers what is not known to be true as false. Each of these …

Design And Development Of An Integrated Web-Based System For Tropical Rainfall Monitoring, Edgar Marko Trono, Maria Leonora Guico, Rollyn T. Labuguen, Andrei Navarro, Nathaniel Joseph C. Libatique, Gregory L. Tangonan

Electronics, Computer, and Communications Engineering Faculty Publications

This study is about the design and development of an integrated web-based system for tropical rainfall monitoring. The system gathers data using a network of low-cost, Android-based acoustic rainfall sensors, a nationwide infrastructure of 5 GHz wireless broadband links, and remote weather stations. The low-cost Android-based acoustic rainfall sensors are deployed at high densities over a local area and the 5 GHz wireless broadband sensors gather rainfall information on a nationwide scale. The sensor network provides information about spatial-variations that are characteristics of tropical rain rates, and complement data from the scarcely deployed remote weather stations. Gathered data is then …

Dynamic Modeling And Analysis Of Generalized Power Flow Controller, B. Vyakaranam, F. E. Villaseca

Electrical and Computer Engineering Faculty Publications

This paper presents a unified solution to compute power quality indices in the generalized unified power flow controller (GUPFC) during steady and transient conditions using a dynamic harmonic domain technique. This technique allows the user to analyze harmonics generated in the GUPFC more precisely than using time domain techniques. The derivation of a model is presented and then simulated in the presence of voltage disturbances to demonstrate its use in power quality assessment. The results of the proposed model are validated against time domain simulations.

Development Of An Optical Sensor For Real-Time Weed Detection Using Laser Based Spectroscopy, Arie Jacobus Paap

Theses: Doctorates and Masters

The management of weeds in agriculture is a time consuming and expensive activity, including in Australia where the predominant strategy is blanket spraying of herbicides. This approach wastes herbicide by applying it in areas where there are no weeds. Discrimination of different plant species can be performed based on the spectral reflectance of the leaves. This thesis describes the development of a sensor for automatic spot spraying of weeds within crop rows. The sensor records the relative intensity of reflected light in three narrow wavebands using lasers as an illumination source.

A prototype weed sensor which had been previously developed …

Semiconductor Laser Based On Thermoelectrophotonics, Xiaohang Liu

Electronic Theses and Dissertations

This dissertation presents to our knowledge the first demonstration of a quantum well (QW) laser monolithically integrated with internal optical pump based on a light emitting diode (LED). The LED with high efficiency is operated in a thermoelectrophotonic (TEP) regime for which it can absorb both its own emitted light and heat. The LED optical pump can reduce internal optical loss in the QW laser, and enables monolithically integrated TEP heat pumps to the semiconductor laser. The design, growth and fabrication processes of the laser chip are discussed, and its experimental data is presented. In order to further increase the …

Multimaterial Fibers In Photonics And Nanotechnology, Guangming Tao

Electronic Theses and Dissertations

Recent progress in combing multiple materials with distinct optical, electronic, and thermomechanical properties monolithically in a kilometer-long fiber drawn from a preform offers unique multifunctionality at a low cost. A wide range of unique in-fiber devices have been developed in fiber form-factor using this strategy. Here, I summary my recent results in this nascent field of 'multimaterial fibers'. I will focus on my achievements in producing robust infrared optical fibers and in appropriating optical fiber production technology for applications in nanofabrication. The development of optical components suitable for the infrared (IR) is crucial for applications in this spectral range to …