Engineering Commons^™

Throughput Analysis Of Buffer-Constrained Wireless Systems In The Finite Blocklength Regime, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, wireless systems operating under queueing constraints in the form of limitations on the buffer violation probabilities are considered. The throughput of wireless systems operating under such constraints is captured by the effective capacity formulation. It is assumed that finite blocklength codes are employed for transmission. Under this assumption, a recent result on the channel coding rate in the finite blocklength regime is incorporated into the analysis and the throughput achieved with such codes in the presence of queueing constraints is identified. Interactions between the effective rate, queueing constraints, error probabilities, and blocklength values are investigated. In particular, …

Self-Reconfigurable Multicell Batteries, Taesic Kim, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The traditional multicell battery design usually employs a fixed configuration to connect multiple cells in series and parallel during operation in order to achieve the required voltage and current. However, this fixed configuration results in low reliability, low fault tolerance, and non-optimal energy conversion efficiency. This paper proposes a novel self reconfigurable, multicell battery design. The proposed multicell battery can automatically configure itself according to the dynamic load/storage demand and the condition of each cell. The proposed battery can self-heal from failure or abnormal operation of single or multiple cells, self-balance from cell state variations, and self-optimize to achieve the …

Raiphy: Phylogenetic Classification Of Metagenomics Samples Using Iterative Refinement Of Relative Abundance Index Profiles, Ozkan U. Nalbantoglu, Samuel F. Way, Steven H. Hinrichs, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

Background: Computational analysis of metagenomes requires the taxonomical assignment of the genome contigs assembled from DNA reads of environmental samples. Because of the diverse nature of microbiomes, the length of the assemblies obtained can vary between a few hundred bp to a few hundred Kbp. Current taxonomic classification algorithms provide accurate classification for long contigs or for short fragments from organisms that have close relatives with annotated genomes. These are significant limitations for metagenome analysis because of the complexity of microbiomes and the paucity of existing annotated genomes.

Results: We propose a robust taxonomic classification method, RAIphy, that …

Energy Efficiency In The Low-Snr Regime Under Queueing Constraints And Channel Uncertainty, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar

Department of Electrical and Computer Engineering: Faculty Publications

Energy efficiency of fixed-rate transmissions is studied in the presence of queueing constraints and channel uncertainty. It is assumed that neither the transmitter nor the receiver has channel side information prior to transmission. The channel coefficients are estimated at the receiver via minimum mean-square-error (MMSE) estimation with the aid of training symbols. It is further assumed that the system operates under statistical queueing constraints in the form of limitations on buffer violation probabilities. The optimal fraction of power allocated to training is identified. Spectral efficiency–bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity …

A Directional Gamma Ray Detector Using A Single Chip Computational Sensor, Nathan R. Schemm, Sina Balkir, Michael W. Hoffman, Mark Bauer

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents the design and test results of a computational radiation sensor system based on a single chip solution that can determine the direction of gamma rays emitted from a radiation source. The overall system is formed by merging a sensor section with a compact and low power computational radiation sensor section. The sensor section houses three NaI gamma ray detectors arranged in a spatial configuration that allows for direction finding. The computational sensor is based on a single chip solution developed by authors that houses multiple low power sensor front ends, event driven analog-to-digital converters, and a dedicated …

Classification Of Military Ground Vehicles Using Time Domain Harmonics’ Amplitudes, Peter E. William, Michael W. Hoffman

Department of Electrical and Computer Engineering: Faculty Publications

In the context of the United Nations peacekeeping operations, we developed an energy-efficient method for the detection and classification of military vehicles using a group of wireless sensors. The method is adequate for low-power unattended sensors which perform sensing, feature extraction, and classification in a standalone scenario. Harmonics’ amplitudes approximating the harmonic signature of the time domain acoustic signal captured by wireless sensor nodes are estimated for vehicle discrimination. The computational complexity for the time domain features extracted from ground vehicles’ acoustic signals is lower than their equivalent spectral features. Classification is performed using a multilayer feed forward neural network, …

Transparent Interconnections Formed By Rapid Single-Step Fabrication Of Graphene Patterns, J. B. Park, W. Xiong, Z. Q. Xie, Y. Gao, M. Qian, M. Mitchell, M. Mahjouri-Samani, Y. S. Zhou, L. Jiang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

We developed a process to form transparent interconnections using graphene patterns that were synthesized by laser chemical vapor deposition. The number of graphene layers was tightly controlled by laser scan speed. Graphene patterns were fabricated at a high scan speed of up to 200 µm/s with a single-step process. The process time is about a million times faster than the conventional chemical vapor deposition method. The fabricated graphene patterns on nickel foils were directly transferred to desired positions on patterned electrodes. The position-controlled transfer with rapid single-step fabrication of graphene patterns provides an innovative pathway for graphene-based interconnections.

Short-Term Solar Power Prediction Using An Rbf Neural Network, Jianwu Zeng, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a radial basis function (RBF) neural network-based model for short-term solar power prediction (SPP). Instead of predicting solar power directly, the model predicts transmissivity, which is then used to obtain solar power according to the extraterrestrial radiation. The proposed model uses a novel two-dimensional (2D) representation for hourly solar radiation and uses historical transmissivity, sky cover, relative humidity and wind speed as the input. Simulation studies are carried out to validate the proposed model for shortterm SPP by using the data obtained from the National Solar Radiation Database (NSRDB). The performance of the RBF neural network is …

Human Detection Using Mobile Embedded Smart Cameras, Li He, Youlu Wang, Senem Velipasalar, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

Embedded smart cameras are stand-alone units that combine sensing and processing on a single embedded platform. They allow flexibility in camera placement, and provide mobility without being dependent on wired links. On the other hand, detecting and tracking objects from videos captured by mobile cameras is a very challenging task even on powerful computers. Since embedded smart cameras have very limited processing power, memory and energy, the challenge becomes even bigger. In this paper, we present a person detection system using an embedded smart camera mounted on a remote-controlled car. We employ histogram of oriented gradients (HOG) for detection, and …

Defending Against Traffic Analysis In Wireless Networks Through Traffic Reshaping, Fan Zhang, Wenbo He, Xue Liu

Department of Electrical and Computer Engineering: Faculty Publications

Traffic analysis has been exploited by attackers to threaten user privacy in wireless networks. As an example, a user’s online activities may be exposed to strangers, even if the traffic is encrypted. However, the existing defense mechanisms against traffic analysis, such as packet padding and traffic morphing, are inefficient because they add noise traffic to blur the traffic features, therefore introducing significant overhead. In this paper, we propose the traffic reshaping technique to thwart traffic analysis. It creates multiple virtual media access control (MAC) interfaces over a single wireless card, dynamically schedules packets over these interfaces, thereby reshaping the packet …

Fast Growth Of Graphene Patterns By Laser Direct Writing, J. B. Park, W. Xiong, Y. Gao, M. Qian, Z. Q. Xie, M. Mitchell, Y. S. Zhou, G. H. Han, L. Jiang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Rapid single-step fabrication of graphene patterns was developed using laser-induced chemical vapor deposition (LCVD). A laser beam irradiates a thin nickel foil in a CH₄ and H₂ environment to induce a local temperature rise, thereby allowing the direct writing of graphene patterns in precisely controlled positions at room temperature. Line patterns can be achieved with a single scan without pre- or post-processes. Surprisingly, the growth rate is several thousand times faster than that of general CVD methods. The discovery and development of the LCVD growth process provide a route for the rapid fabrication of graphene patterns for various …

Small Molecule Inhibitors Of Staphylococcus Aureus Rnpa Alter Cellular Mrna Turnover, Exhibit Antimicrobial Activity, And Attenuate Pathogenesis, Patrick D. Olson, Lisa J. Kuechenmeister, Kelsi L. Anderson, Sonja Daily, Karen E. Beenken, Christelle M. Roux, Michelle L. Reniere, Tami L. Lewis, William J, Weiss, Mark Pulse, Phung Nguyen, Jerry W. Simecka, John M. Morrison, Khalid Sayood, Oluwatoyin A. Asojo, Mark S. Smeltzer, Eric P. Skaar, Paul M. Dunman

Department of Electrical and Computer Engineering: Faculty Publications

Methicillin-resistant Staphylococcus aureus is estimated to cause more U.S. deaths annually than HIV/AIDS. The emergence of hypervirulent and multidrug-resistant strains has further amplified public health concern and accentuated the need for new classes of antibiotics. RNA degradation is a required cellular process that could be exploited for novel antimicrobial drug development. However, such discovery efforts have been hindered because components of the Gram-positive RNA turnover machinery are incompletely defined. In the current study we found that the essential S. aureus protein, RnpA, catalyzes rRNA and mRNA digestion in vitro. Exploiting this activity, high through-put and secondary screening assays identified …

Impact Of Porogens On The Pore Characteristics Of Zirconia Particles Made By Polymer-Induced Colloid Aggregation, Abhinandan Pattanayak, Anuradha Subramanian

Anuradha Subramanian Publications

Zirconia particles were prepared from a 20% colloidal sol (ZrO₂) by the polymer-induced colloid aggregation (PICA) process, both in the presence and absence of porogens. Specifically, porous zirconia particles having varying porosity were prepared by a two-step protocol wherein a porogen was first embedded during the particle synthesis, followed by its removal in a subsequent step. In this research study, the ability of four different types of porogens, viz. fumed silica, micronized high molecular weight polyethylene emulsion ME09730, and microcrystalline waxes ME48040M2 and ME98040M1, to impact the pore size, porosity, and pore area were investigated. Particle morphology and …

A Novel Adaptive Distributed Cooperative Relaying Mac Protocol For Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Tao Ma

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Explosive growth in Information Technology has enabled many innovative application areas such as large-scale outdoor vehicular networks for vehicle-to-vehicle communications. By providing time-sensitive and location-aware information, vehicular networks can contribute to a safer and more efficient driving experience. However, the performance of vehicular networks requires robust and real-time data communications and is impacted by high mobility, intermittent connectivity, and unreliability of the wireless channel. In this paper, a novel adaptive distributed cooperative medium access control (ADCMAC) protocol is proposed in order to address the inherent problems in the IEEE 802.11 standard when employed in vehicular networks. ADC-MAC exploits spatial diversities …

Quantitative Analysis Of Propagation Characteristics For Mobile Wimax, Pradhumna Shrestha, Puttipong Mahasukhon, Michael Hempel, Tao Ma, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In wireless networks, careful planning and link budget analysis is required for delivering maximum throughput reliably with minimum overhead. The efficiency of planning and eventual network performance is totally dependent upon the accuracy and quality of data used for analysis. In most studies, computer simulations and analytical models are used for generating such data. However these simulations are limited to many assumptions which are different from the actual implemented hardware, therefore, the data generated are not accurate. In this paper, we analyze the performance of Mobile WiMAX utilizing the empirical data measured from leading WiMAX equipment. We believe this data …

Power Controlled Coded-Sequence Self-Encoded Spread Spectrum Communications, Poomathi Duraisamy, Liang Chi, Won Mee Jang, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we propose to apply power control to coded-sequence self-encoded spread spectrum (CS-SESS) communications in dynamic fading channels. We determine the statistical characteristics of the power enhancement in the transmitter due to power control and show that the proposed approach improves the power efficiency in mobile cellular systems.

In addition, we propose to mitigate self interference in CSSESS by exploiting the information that the transmitter obtains, through feedback training sequences, about the de-spreading code in the receiver. The results show that the mitigation is significant even with only selective training chips from the de-spreading sequence. Similar improvement can …

A Study On Energy Efficient Multi-Tier Multi-Hop Wireless Sensor Networks For Freight-Train Monitoring, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Tao Ma, Pradhumna Shrestha

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

The North American freight railroad industry is trying to leverage wireless sensor networks (WSN) onboard railcars for advanced monitoring and alerting. In railroad environments, freight train WSNs exhibit a linear chain-like topology of significant length. Thus, existing wireless technologies such as the IEEE 802.15.4 communication protocol, based on a star topology, are unable to provide reliable service. The end-to-end communication between nodes generally relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the preferred destination. The routing performance and reliability significantly degrades with increasing number of hops. We proposed …

Thz Dielectric Anisotropy Of Metal Slanted Columnar Thin Films, Tino Hofmann, D. Schmidt, A. Boosalis, P. Kuhne, Ralph Skomski, C. M. Herzinger, John A. Woollam, Mathias Schubert, Eva Schubert

Department of Electrical and Computer Engineering: Faculty Publications

The anisotropic optical dielectric functions of a metal (cobalt) slanted columnar thin film deposited by electron-beam glancing angle deposition are reported for the terahertz (THz) frequency domain using generalized spectroscopic ellipsometry. We employ a simple effective medium dielectric function homogenization approach to describe the observed optical response. The approach describes isolated, electrically conductive columns which render the thin film biaxial (orthorhombic). Our findings suggest controlled variability of dielectric polarizability and anisotropy in the THz spectral range by choice of geometry, material, and structure.

A High-Quality Mach-Zehnder Interferometer Fiber Sensor By Femtosecond Laser One-Step Processing, Longjiang Zhao, Lan Jiang, Sumei Wang, Hai Xiao, Yongfeng Lu, Hai-Lung Tsai

Department of Electrical and Computer Engineering: Faculty Publications

During new fiber sensor development experiments, an easy-to-fabricate simple sensing structure with a trench and partially ablated fiber core is fabricated by using an 800 nm 35 fs 1 kHz laser. It is demonstrated that the structure forms a Mach-Zehnder interferometer (MZI) with the interference between the laser light passing through the air in the trench cavity and that in the remained fiber core. The fringe visibilities are all more than 25 dB. The transmission spectra vary with the femtosecond (fs) laser ablation scanning cycle. The free spectral range (FSR) decreases as the trench length increases. The MZI structure is …

Transit System Evaluation Process: From Planning To Realization, K Bartman, Jennifer Ogle, Mashrur Chowdhury, Anne Dunning

Publications

Many frameworks exist to help transit agencies plan, operate, and monitor the performance of transit in rural and urban communities. No framework integrates these three critical business practices into one coherent and flexible framework useful to rural and small-sized cities. The primary objective of this research was to integrate planning, operations, and performance measurement activities into a framework designed to evaluate transit in the context of overall mobility. By combining planning, evaluation, and performance monitoring processes, a succinct framework useful to transit agencies and planners was created. In addition to city entities, colleges and universities operating or contracting transit systems …

A Web Application For Financial Trading Simulation, Li-Chiou Chen, Lixin Tao, Padma Kadiyala

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.

Digital Holographic Imaging Of Aerosol Particles In Flight, Matthew J. Berg, Gorden Videen

United States Army: Publications

This work describes the design and application of an apparatus to image aerosol
particles using digital holography in a flow-through, contact-free manner. Particles in an aerosol stream are illuminated by a triggered, pulsed laser and the pattern produced by the interference of this light with that scattered by the particles is recorded by a digital camera. The recorded pattern constitutes a digital hologram from which an image of the particles is computationally reconstructed using a fast Fourier transform. This imaging is validated using a cluster of ragweed pollen particles. Examples involving mineral-dust aerosols demonstrate the technique’s in situ imaging capability …

Application Of Hyperspectral Vegetation Indices To Detect Variations In High Leaf Area Index Temperate Shrub Thicket Canopies, Steven T. Brantley, Julie C. Zinnert, Donald R. Young

United States Army: Publications

Accurate measurement of leaf area index (LAI), an important characteristic of plant canopies directly linked to primary production, is essential for monitoring changes in ecosystem C stocks and other ecosystem level fluxes. Direct measurement of LAI is labor intensive, impractical at large scales and does not capture seasonal or annual variations in canopy biomass. The need to monitor canopy related fluxes across landscapes makes remote sensing an attractive technique for estimating LAI. Many vegetation indices, such as Normalized Difference Vegetation Index (NDVI), tend to saturate at LAI levels >4 although tropical and temperate forested ecosystems often exceed that threshold. Using …

Purification Of A Recombinant Heavy Chain Fragment C Vaccine Candidate Against Botulinum Serotype C Neurotoxin [Rbontc(HC)] Expressed In Pichia Pastoris, Michael P. Dux, Jicai Huang, Rick Barent, Mehmet Inan, S. Todd Swanson, Jayanta Sinha, John T. Ross, Leonard A. Smith, Theresa J. Smith, Ian Henderson, Michael M. Meagher

United States Army: Publications

A purification process for the manufacture of a recombinant C-terminus heavy chain fragment from botulinum neurotoxin serotype C [rBoNTC(H_c)], a potential vaccine candidate, has been defined and successfully scaled-up. The rBoNTC(H_c) was produced intracellularly in Pichia pastoris X-33 using a three step fermentation process, i.e., glycerol batch phase, a glycerol fed-batch phase to achieve high cell densities, followed by a methanol induction phase. The rBoNTC(H_c) was captured from the soluble protein fraction of cell lysate using hydrophobic charge induction chromatography (HCIC; MEP HyperCel™), and then further purified using a CM 650M ion exchange chromatography …

Charge And Fluence Lifetime Measurements Of A Dc High Voltage Gaas Photogun At High Average Current, J. Grames, R. Suleiman, P. A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M. L. Stutzman

United States Department of Energy: Publications

GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center …

Pwisegen: Generating Test Cases For Pairwise Testing Using Genetic Algorithms, Pedro Flores, Yoonsik Cheon

Departmental Technical Reports (CS)

Pairwise testing is a combinatorial testing technique that tests all possible pairs of input values. Although, finding a smallest set of test cases for pairwise testing is NP-complete, pairwise testing is regarded as a reasonable cost-benefit compromise among combinatorial testing methods. In this paper we formulate the problem of finding a pairwise test set as a search problem and apply a genetic algorithm to solve it. We also describe an open-source tool called PWiseGen for generating pairwise test sets. According to our experiments, PWiseGen produces competitive results compared with existing pairwise testing tools. Besides, it provides a framework and a …

Towards Optimal Few-Parametric Representation Of Spatial Variation: Geometric Approach And Environmental Applications, Misha Kosheleva, Octavio Lerma, Craig Tweedie

Departmental Technical Reports (CS)

In this paper, we use geometric approach to showthat under reasonable assumption, the spatialvariability of a field f(x), i.e., the expectedvalue F(z)=E[(f(x+z)-f(x))²], has the formF(z)=|Σ g_ij*z_i*z_j|^α.We explain how to find g_ij and αfrom the observations, and how to optimally place sensorsin view of this spatial variability.

Measures Of Deviation (And Dependence) For Heavy-Tailed Distributions And Heir Estimation Under Interval And Fuzzy Uncertainty, Nitaya Buntao, Vladik Kreinovich

Departmental Technical Reports (CS)

Traditionally, in science and engineering, most statistical techniques are based on the assumption that the random variables are normally distributed. For such distributions, a natural characteristic of the "average" value is the mean, and a natural characteristic of the deviation from the average is the variance. However, in many practical situations, e.g., in economics and finance, we encounter probability distributions for which the variance is infinite; such distributions are called heavy-tailed. For such distributions, we describe which characteristics can be used to describe the average and the deviation from the average, and how to estimate these characteristics under interval …

Dynamic Response Of Brain Subjected To Blast Loadings: Influence Of Frequency Ranges, Mehdi S. Chafi, Shailesh G. Ganpule, Linxia Gu, Namas Chandra

Department of Mechanical and Materials Engineering: Faculty Publications

Blast wave induced a frequency spectrum and large deformation of the brain tissue. In this study, new material parameters for the brain material are determined from the experimental data pertaining to these large strain amplitudes and wide frequencies ranging (from 0.01 Hz to 10 MHz) using genetic algorithms. Both hyperelastic and viscoelastic behavior of the brain are implemented into 2D finite element models and the dynamic responses of brain are evaluated. The head, composed of triple layers of the skull, including two cortical layers and a middle dipole sponge-like layer, the dura, cerebrospinal fluid (CSF), the pia mater and the …

Intelligent Processing In Wireless Communications Using Particle Swarm Based Methods, Weihua Gao

Electrical Engineering and Computer Science - Dissertations

There are a lot of optimization needs in the research and design of wireless communica- tion systems. Many of these optimization problems are Nondeterministic Polynomial (NP) hard problems and could not be solved well. Many of other non-NP-hard optimization problems are combinatorial and do not have satisfying solutions either. This dissertation presents a series of Particle Swarm Optimization (PSO) based search and optimization algorithms that solve open research and design problems in wireless communications. These problems are either avoided or solved approximately before.

PSO is a bottom-up approach for optimization problems. It imposes no conditions on the underlying problem. Its …