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Electrical and Computer Engineering
Electrical and Computer Engineering Faculty Research and Publications
- Keyword
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- Acoustic modeling (1)
- Agroacoustics (1)
- Baseline drift compensation (1)
- Biosensors (1)
- Boundary Value Problems (1)
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- Camera networks (1)
- Carbon nanotube growth (1)
- Chemical and biological sensors (1)
- Chemical sensors (1)
- Chemical technology (1)
- Cluster analysis (1)
- Condensed Matter: Electrical (1)
- Data mining (1)
- Data sets (1)
- Distributed tracking (1)
- Dot-in-a-well (DWELL) quantum-dot detectors (1)
- Electromagnetic Scattering (1)
- Face tracking (1)
- Focal plane arrays (1)
- Hydrogen plasma (1)
- Hyperspectral imaging (1)
- Hyperspectral sensors (1)
- Image registration (1)
- Infrared (1)
- Interfaces and Thin Films (1)
- Isolation technology (1)
- Knowledge discovery in data (1)
- Machine learing (1)
- Magnetic and Optical (1)
- Monitoring (1)
Articles 1 - 14 of 14
Full-Text Articles in Computer Engineering
Integrated Freestanding Single-Crystal Silicon Nanowires: Conductivity And Surface Treatment, Chung-Hoon Lee, Clark Ritz, Minghuang Huang, Michael Ziwisky, Robert Blise, Max Lagally
Integrated Freestanding Single-Crystal Silicon Nanowires: Conductivity And Surface Treatment, Chung-Hoon Lee, Clark Ritz, Minghuang Huang, Michael Ziwisky, Robert Blise, Max Lagally
Electrical and Computer Engineering Faculty Research and Publications
Integrated freestanding single-crystal silicon nanowires with typical dimension of 100 nm × 100 nm × 5 µm are fabricated by conventional 1:1 optical lithography and wet chemical silicon etching. The fabrication procedure can lead to wafer-scale integration of silicon nanowires in arrays. The measured electrical transport characteristics of the silicon nanowires covered with/without SiO2 support a model of Fermi level pinning near the conduction band. The I–V curves of the nanowires reveal a current carrier polarity reversal depending on Si–SiO2 and Si–H bonds on the nanowire surfaces
Midwave Infrared Quantum Dot Avalanche Photodiode, David A. Ramirez, Jiayi Shao, Majeed M. Hayat, Sanjay Krishna
Midwave Infrared Quantum Dot Avalanche Photodiode, David A. Ramirez, Jiayi Shao, Majeed M. Hayat, Sanjay Krishna
Electrical and Computer Engineering Faculty Research and Publications
We report the first demonstration of a GaAs based avalanche photodiode (APD) operating in the midwave infrared region . In the device, called the quantum dot avalanche photodiode, an intersubband quantum dots-in-a-well detector is coupled with an APD through a tunnel barrier. Using this approach, we have increased the photocurrent and reached a conversion efficiency of 12%, which is one of the highest reported conversion efficiencies for any quantum dot detector.
A Parallel Histogram-Based Particle Filter For Object Tracking On Simd-Based Smart Cameras, Henry Medeiros, Germán Holguín, Paul J. Shin, Johnny Park
A Parallel Histogram-Based Particle Filter For Object Tracking On Simd-Based Smart Cameras, Henry Medeiros, Germán Holguín, Paul J. Shin, Johnny Park
Electrical and Computer Engineering Faculty Research and Publications
We present a parallel implementation of a histogram-based particle filter for object tracking on smart cameras based on SIMD processors. We specifically focus on parallel computation of the particle weights and parallel construction of the feature histograms since these are the major bottlenecks in standard implementations of histogram-based particle filters. The proposed algorithm can be applied with any histogram-based feature sets—we show in detail how the parallel particle filter can employ simple color histograms as well as more complex histograms of oriented gradients (HOG). The algorithm was successfully implemented on an SIMD processor and performs robust object tracking at up …
Mas Pole Location And Effective Spatial Bandwidth Of The Scattered Field, James Richie
Mas Pole Location And Effective Spatial Bandwidth Of The Scattered Field, James Richie
Electrical and Computer Engineering Faculty Research and Publications
The concept of effective spatial bandwidth (EBW) is introduced for periodic domains. The EBW is applied to the incident and scattered fields along the boundary of an infinite circular cylinder. The scattered field is formulated using the method of auxiliary sources (MAS). In MAS, monopoles on an auxiliary surface (AS) are used to model the scattered field. It is shown that the EBW of the incident field can provide some insight regarding the placement of poles for the MAS scattered field model. Example simulations are provided to demonstrate the usefulness of EBW with respect to monopole placement rules in MAS.
Maximizing Service Reliability In Distributed Computing Systems With Random Node Failures: Theory And Implementation, Jorge E. Pezoa, Sagar Dhakal, Majeed M. Hayat
Maximizing Service Reliability In Distributed Computing Systems With Random Node Failures: Theory And Implementation, Jorge E. Pezoa, Sagar Dhakal, Majeed M. Hayat
Electrical and Computer Engineering Faculty Research and Publications
In distributed computing systems (DCSs) where server nodes can fail permanently with nonzero probability, the system performance can be assessed by means of the service reliability, defined as the probability of serving all the tasks queued in the DCS before all the nodes fail. This paper presents a rigorous probabilistic framework to analytically characterize the service reliability of a DCS in the presence of communication uncertainties and stochastic topological changes due to node deletions. The framework considers a system composed of heterogeneous nodes with stochastic service and failure times and a communication network imposing random tangible delays. The framework also …
Cluster-Based Distributed Face Tracking In Camera Networks, Josiah Yoder, Henry Medeiros, Johnny Park, Avinash Kak
Cluster-Based Distributed Face Tracking In Camera Networks, Josiah Yoder, Henry Medeiros, Johnny Park, Avinash Kak
Electrical and Computer Engineering Faculty Research and Publications
In this paper, we present a distributed multicamera face tracking system suitable for large wired camera networks. Unlike previous multicamera face tracking systems, our system does not require a central server to coordinate the entire tracking effort. Instead, an efficient camera clustering protocol is used to dynamically form groups of cameras for in-network tracking of individual faces. The clustering protocol includes cluster propagation mechanisms that allow the computational load of face tracking to be transferred to different cameras as the target objects move. Furthermore, the dynamic election of cluster leaders provides robustness against system failures. Our experimental results show that …
Online Drift Compensation For Chemical Sensors Using Estimation Theory, Thomas H. Wenzel, Arnold Kweku Mensah-Brown, Fabien Josse, Edwin E. Yaz
Online Drift Compensation For Chemical Sensors Using Estimation Theory, Thomas H. Wenzel, Arnold Kweku Mensah-Brown, Fabien Josse, Edwin E. Yaz
Electrical and Computer Engineering Faculty Research and Publications
Sensor drift from slowly changing environmental conditions and other instabilities can greatly degrade a chemical sensor's performance, resulting in poor identification and analyte quantification. In the present work, estimation theory (i.e., various forms of the Kalman filter) is used for online compensation of baseline drift in the response of chemical sensors. Two different cases, which depend on the knowledge of the characteristics of the sensor system, are studied. First, an unknown input is considered, which represents the practical case of analyte detection and quantification. Then, the more general case, in which the sensor parameters and the input are both unknown, …
Knowledge Discovery And Analysis In Manufacturing, Mark Polczynski, Andzrej Kochanski
Knowledge Discovery And Analysis In Manufacturing, Mark Polczynski, Andzrej Kochanski
Electrical and Computer Engineering Faculty Research and Publications
The quality and reliability requirements for next-generation manufacturing are reviewed, and current approaches are cited. The potential for augmenting current quality/reliability technology is described, and characteristics of potential future directions are postulated. Methods based on knowledge discovery and analysis in manufacturing (KDAM) are reviewed, and related successful applications in business and social fields are discussed. Typical KDAM applications are noted, along with general functions and specific KDAM-related technologies. A systematic knowledge discovery process model is reviewed, and examples of current work are given, including description of successful applications of KDAM to creation of rules for optimizing gas porosity in sand …
Editorial Special Issue On Enhancement Algorithms, Methodologies And Technology For Spectral Sensing, James O. Jensen, Robert J. Trew, Dwight L. Woolard, Neelam Gupta, Jean-Marc Theriault, Majeed M. Hayat, Yanqiu Li, Patti Gillespie
Editorial Special Issue On Enhancement Algorithms, Methodologies And Technology For Spectral Sensing, James O. Jensen, Robert J. Trew, Dwight L. Woolard, Neelam Gupta, Jean-Marc Theriault, Majeed M. Hayat, Yanqiu Li, Patti Gillespie
Electrical and Computer Engineering Faculty Research and Publications
The paper is an editorial issue on enhancement algorithms, methodologies and technology for spectral sensing and serves as a valuable and useful reference for researchers and technologists interested in the evolving state-of-the-art and/or the emerging science and technology base associated with spectral-based sensing and monitoring problem. This issue is particularly relevant to those seeking new and improved solutions for detecting chemical, biological, radiological and explosive threats on the land, sea, and in the air.
Shift Estimation Algorithm For Dynamic Sensors With Frame-To-Frame Variation In Their Spectral Response, Todd M. Giles, Majeed M. Hayat, Sanjay Krishna
Shift Estimation Algorithm For Dynamic Sensors With Frame-To-Frame Variation In Their Spectral Response, Todd M. Giles, Majeed M. Hayat, Sanjay Krishna
Electrical and Computer Engineering Faculty Research and Publications
This study is motivated by the emergence of a new class of tunable infrared spectral-imaging sensors that offer the ability to dynamically vary the sensor's intrinsic spectral response from frame to frame in an electronically controlled fashion. A manifestation of this is when a sequence of dissimilar spectral responses is periodically realized, whereby in every period of acquired imagery, each frame is associated with a distinct spectral band. Traditional scene-based global shift estimation algorithms are not applicable to such spectrally heterogeneous video sequences, as a pixel value may change from frame to frame as a result of both global motion …
Acoustic Censusing Using Automatic Vocalization Classification And Identity Recognition, Kuntoro Adi, Michael T. Johnson, Tomasz S. Osiejuk
Acoustic Censusing Using Automatic Vocalization Classification And Identity Recognition, Kuntoro Adi, Michael T. Johnson, Tomasz S. Osiejuk
Electrical and Computer Engineering Faculty Research and Publications
This paper presents an advanced method to acoustically assess animal abundance. The framework combines supervised classification (song-type and individual identity recognition), unsupervised classification (individual identity clustering), and the mark-recapture model of abundance estimation. The underlying algorithm is based on clustering using hidden Markovmodels (HMMs) and Gaussian mixture models (GMMs) similar to methods used in the speech recognition community for tasks such as speaker identification and clustering. Initial experiments using a Norwegian ortolan bunting (Emberiza hortulana) data set show the feasibility and effectiveness of the approach. Individually distinct acoustic features have been observed in a wide range of animal …
Effects Of Hydrogen Pretreatment On Physical-Vapor-Deposited Nickel Catalyst For Multi-Walled Carbon Nanotube Growth, Benjamin L. Crossley, Mauricio Kossler, Ronald A. Coutu Jr., Lavern A. Starman, Peter J. Collins
Effects Of Hydrogen Pretreatment On Physical-Vapor-Deposited Nickel Catalyst For Multi-Walled Carbon Nanotube Growth, Benjamin L. Crossley, Mauricio Kossler, Ronald A. Coutu Jr., Lavern A. Starman, Peter J. Collins
Electrical and Computer Engineering Faculty Research and Publications
Physical vapor deposited nickel catalyst layers of 10, 50, 100, 200, 350, and 500 angstroms were granulated using hydrogen plasma for varying times to determine an effective carbon nanotube (CNT) growth process using microwave plasma enhanced CVD (MPECVD). Nickel was deposited via sputtering or evaporation. The catalyst granule size, density, and resulting CNTs were analyzed. Sputtered nickel of 50 angstroms with 5 minutes of hydrogen plasma pretreatment resulted in the most effective CNT growth.
Information Theoretic Approach For Assessing Image Fidelity In Photon-Counting Arrays, Srikanth R. Narravula, Majeed M. Hayat, Bahram Javidi
Information Theoretic Approach For Assessing Image Fidelity In Photon-Counting Arrays, Srikanth R. Narravula, Majeed M. Hayat, Bahram Javidi
Electrical and Computer Engineering Faculty Research and Publications
The method of photon-counting integral imaging has been introduced recently for three-dimensional object sensing, visualization, recognition and classification of scenes under photon-starved conditions. This paper presents an information-theoretic model for the photon-counting imaging (PCI) method, thereby providing a rigorous foundation for the merits of PCI in terms of image fidelity. This, in turn, can facilitate our understanding of the demonstrated success of photon-counting integral imaging in compressive imaging and classification. The mutual information between the source and photon-counted images is derived in a Markov random field setting and normalized by the source-image’s entropy, yielding a fidelity metric that is between …
Measurement And Modeling Of Infrared Nonlinear Absorption Coefficients And Laser-Induced Damage Thresholds In Ge And Gasb, T. J. Wagner, M. A. Bohn, Ronald A. Coutu Jr., L. P. Gonzalez, J. M. Murray, K. L. Schepler, S. Guha
Measurement And Modeling Of Infrared Nonlinear Absorption Coefficients And Laser-Induced Damage Thresholds In Ge And Gasb, T. J. Wagner, M. A. Bohn, Ronald A. Coutu Jr., L. P. Gonzalez, J. M. Murray, K. L. Schepler, S. Guha
Electrical and Computer Engineering Faculty Research and Publications
Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 μm for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 μm and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al2O3 anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for picosecond or nanosecond …