Computer Engineering Commons^™

Homogenous Ensemble Phonotactic Language Recognition Based On Svm Supervector Reconstruction, Wei-Wei Liu, Wei-Qiang Zhang, Michael T. Johnson, Jia Liu

Electrical and Computer Engineering Faculty Research and Publications

Currently, acoustic spoken language recognition (SLR) and phonotactic SLR systems are widely used language recognition systems. To achieve better performance, researchers combine multiple subsystems with the results often much better than a single SLR system. Phonotactic SLR subsystems may vary in the acoustic features vectors or include multiple language-specific phone recognizers and different acoustic models. These methods achieve good performance but usually compute at high computational cost. In this paper, a new diversification for phonotactic language recognition systems is proposed using vector space models by support vector machine (SVM) supervector reconstruction (SSR). In this architecture, the subsystems share the same …

A Microfluidic Device For Thermal Particle Detection, Ashwin Kumar Vutha, Benyamin Davaji, Chung-Hoon Lee, Glenn M. Walker

Electrical and Computer Engineering Faculty Research and Publications

We demonstrate the use of heat to count microscopic particles. A thermal particle detector (TPD) was fabricated by combining a 500-nm-thick silicon nitride membrane containing a thin-film resistive temperature detector with a silicone elastomer microchannel. Particles with diameters of 90 and 200 μm created relative temperature changes of 0.11 and −0.44 K, respectively, as they flowed by the sensor. A first-order lumped thermal model was developed to predict the temperature changes. Multiple particles were counted in series to demonstrate the utility of the TPD as a particle counter.

A Microsoft Vba Application For Generating Heat Maps, Mark Polczynski, Michael Polczynski

Electrical and Computer Engineering Faculty Research and Publications

A choropleth map is a form of thematic map used to portray the structural characteristics of some particular geographical distribution not apparent in data presented in tabular form. Preparation of a choropleth map starts with the assignment of map features to classes based on the value of a specific feature attribute followed by the association of classes of features with appropriate map colors or symbols. Map features are often geographical regions with naturally or artificially defined boundaries, but choropleth maps can also be prepared by segmenting the area to be mapped into a regular grid of regions. Maps prepared with …

A Paper-Based Calorimetric Microfluidics Platform For Bio-Chemical Sensing, Benyamin Davaji, Chung Hoon Lee

Electrical and Computer Engineering Faculty Research and Publications

In this report, a paper-based micro-calorimetric biochemical detection method is presented. Calorimetric detection of biochemical reactions is demonstrated as an extension of current colorimetric and electrochemical detection mechanisms of paper-based biochemical analytical systems. Reaction and/or binding temperature of glucose/glucose oxidase, DNA/hydrogen peroxide, and biotin/streptavidin, are measured by the paper-based micro-calorimeter. Commercially available glucose calibration samples of 0.05, 0.15 and 0.3% wt/vol concentration are used for comparing the device performance with a commercially available glucose meter (electrochemical detection). The calorimetric glucose detection demonstrates a measurement error less than 2%. The calorimetric detection results of DNA concentrations from 0.9 to 7.3 mg/mL …

Application Of Information And Communication Technologies For Historical Research, Michael Polczynski, Mark Polczynski

Electrical and Computer Engineering Faculty Research and Publications

No abstract provided.

Multi-Objective Tradeoffs In The Design Optimization Of A Brushless Permanent-Magnet Machine With Fractional-Slot Concentrated Windings, Peng Zhang, Gennadi Y. Sizov, Muyang Li, Dan M. Ionel, Nabeel Demerdash, Steven J. Stretz, Alan W. Yeadon

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a robust parametric model of a brushless permanent magnet machine with fractional-slot concentrated windings, which was developed for automated design optimization is presented. A computationally efficient finite-element analysis method was employed to estimate the dq-axes inductances, the induced voltage and torque ripple waveforms, and losses of the machine. A method for minimum effort calculation of the torque angle corresponding to the maximum torque per ampere load condition was developed. A differential evolution algorithm was implemented for the global design optimization with two concurrent objectives of minimum losses and minimum material cost. An engineering decision process based on …

Generalized Approach Of Stator Shifting In Interior Permanent-Magnet Machines Equipped With Fractional-Slot Concentrated Windings, Patel B. Reddy, Kum-Kang Huh, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Electrical drive systems, which include electrical machines and power electronics, are a key enabling technology for advanced vehicle propulsion systems that reduce the petroleum dependence of the ground transportation sector. To have significant effect, electric drive technologies must be economical in terms of cost, weight, and size while meeting performance and reliability expectations. Interior permanent magnet machines with fractional-slot concentrated windings have been shown to be good candidates for hybrid traction applications. One of the key challenges is the additional stator magnetomotive force sub- and superharmonic components that lead to higher losses in the rotor as well as saturation effects. …

Comparative Assessment Of Diverse Strategies For Malaria Vector Population Control Based On Measured Rates At Which Mosquitoes Utilize Targeted Resource Subsets, Gerry F. Killeen, Samson Sifael Kiware, Aklilu Seyoum, John E. Gimnig, George Corliss, Jennifer Stevenson, Christopher J. Drakeley, Nakul Chitnis

Electrical and Computer Engineering Faculty Research and Publications

Background

Eliminating malaria requires vector control interventions that dramatically reduce adult mosquito population densities and survival rates. Indoor applications of insecticidal nets and sprays are effective against an important minority of mosquito species that rely heavily upon human blood and habitations for survival. However, complementary approaches are needed to tackle a broader diversity of less human-specialized vectors by killing them at other resource targets.

Methods

Impacts of strategies that target insecticides to humans or animals can be rationalized in terms of biological coverage of blood resources, quantified as proportional coverage of all blood resources mosquito vectors utilize. Here, this concept …

Deterministic And Stochastic Resilience Analysis Of Minimum-Time-Controlled Discrete-Time Systems, Jennifer L. Bonniwell, Susan C. Schneider Phd, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

The resilience of discrete-time systems subject to minimum-time control is analysed for both deterministic and stochastic control gain perturbations. Lyapunov analysis is used to determine a tight upper bound on the control gain perturbations to maintain asymptotic stability.

Stochastic Analysis Of Cascading-Failure Dynamics In Power Grids, Mahshid Rahnamay-Naeini, Zhuoyao Wang, Nasir Ghani, Andrea Mammoli, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

A scalable and analytically tractable probabilistic model for the cascading failure dynamics in power grids is constructed while retaining key physical attributes and operating characteristics of the power grid. The approach is based upon extracting a reduced abstraction of large-scale power grids using a small number of aggregate state variables while modeling the system dynamics using a continuous-time Markov chain. The aggregate state variables represent critical power-grid attributes, which have been shown, from prior simulation-based and historical-data-based analysis, to strongly influence the cascading behavior. The transition rates among states are formulated in terms of certain parameters that capture grid's operating …

Terahertz Photoacoustic Spectroscopy Using An Mems Cantilever Sensor, Nathan E. Giauvitz, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a microelectromechanical systems cantilever sensor was designed, modeled, and fabricated to measure the photoacoustic (PA) response of gases under very low vacuum conditions. The micromachined devices were fabricated using silicon-on-insulator wafers and then tested in a custom-built, miniature, vacuum chamber during this first-ever demonstration. Terahertz radiation was amplitude modulated to excite the gas under test and perform PA molecular spectroscopy. Experimental data show a predominantly linear response that directly correlates measured cantilever deflection to PA signals. Excellent low pressure (i.e., 2-40 mTorr) methyl cyanide PA spectral data were collected resulting in a system sensitivity of 1.97 × …

Reduction Of Vibration-Induced Artifacts In Synthetic Aperture Radar Imagery, Qi Wang, Matthew Pepin, Aleck Wright, Ralf Dunkel, Tom Atwood, Balu Santhanam, Walter Gerstle, Armin W. Doerry, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

Target vibrations introduce nonstationary phase modulation, which is termed the micro-Doppler effect, into returned synthetic aperture radar (SAR) signals. This causes artifacts, or ghost targets, which appear near vibrating targets in reconstructed SAR images. Recently, a vibration estimation method based on the discrete fractional Fourier transform (DFrFT) has been developed. This method is capable of estimating the instantaneous vibration accelerations and vibration frequencies. In this paper, a deghosting method for vibrating targets in SAR images is proposed. For single-component vibrations, this method first exploits the estimation results provided by the DFrFT-based vibration estimation method to reconstruct the instantaneous vibration displacements. …

Electrical Machine Topologies: Hottest Topics In The Electrical Machine Research Community, Aldo Boglietti, Ayman M. El-Refaie, Oliver Drubel, Avoki M. Omekanda, Nicola Bianchi, Emmanuel B. Agamloh, Mircea Popescu, Antonino Di Gerlando, James Borg Bartolo

Electrical and Computer Engineering Faculty Research and Publications

In this article, the state of the art in electrical machine design is outlined underlining the problems and challenges to be solved by engineers. As highlighted in this article, even if electrical machine design is often considered a mature issue from the technical and technological point of view, every year, new progresses and steps forward are made. New and more sophisticated design tools can be used worldwide, and innovative manufacturing processes, new insulation materials, and higher performance magnetic materials are available on the market. In addition, the evolution of the hardware used in digital control and new powerful power electronic …

Model-Based Edge Detector For Spectral Imagery Using Sparse Spatiospectral Masks, Biliana S. Paskaleva, Sebastian E. Godoy, Woo-Yong Jang, Steven C. Bender, Sanjay Krishna, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

Two model-based algorithms for edge detection in spectral imagery are developed that specifically target capturing intrinsic features such as isoluminant edges that are characterized by a jump in color but not in intensity. Given prior knowledge of the classes of reflectance or emittance spectra associated with candidate objects in a scene, a small set of spectral-band ratios, which most profoundly identify the edge between each pair of materials, are selected to define a edge signature. The bands that form the edge signature are fed into a spatial mask, producing a sparse joint spatiospectral nonlinear operator. The first algorithm achieves edge …

Evaluation Of The Importance Of Time-Frequency Contributions To Speech Intelligibility In Noise, Chengzhu Yu, Kamil K. Wójcicki, Philipos C. Loizou, John H. L. Hansen, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

Recent studies on binary masking techniques make the assumption that each time-frequency (T-F) unit contributes an equal amount to the overall intelligibility of speech. The present study demonstrated that the importance of each T-F unit to speech intelligibility varies in accordance with speech content. Specifically, T-F units are categorized into two classes, speech-present T-F units and speech-absent T-F units. Results indicate that the importance of each speech-present T-F unit to speech intelligibility is highly related to the loudness of its target component, while the importance of each speech-absent T-F unit varies according to the loudness of its masker component. Two …

A Novel On-Chip Three-Dimensional Micromachined Calorimeter With Fully Enclosed And Suspended Thin-Film Chamber For Thermal Characterization Of Liquid Samples, Benyamin Davaji, Hye Jeong Bak, Woo-Jin Chang, Chung-Hoon Lee

Electrical and Computer Engineering Faculty Research and Publications

A microfabricated calorimeter (μ-calorimeter) with an enclosed reaction chamber is presented. The 3D micromachined reaction chamber is capable of analyzing liquid samples with volume of 200 nl. The thin film low-stress silicon nitride membrane is used to reduce thermal mass of the calorimeter and increase the sensitivity of system. The μ-calorimeter has been designed to perform DC and AC calorimetry, thermal wave analysis, and differential scanning calorimetry. The μ-calorimeter fabricated with an integrated heater and a temperature sensor on opposite sides of the reaction chamber allows to perform thermal diffusivity and specific heat measurements on liquid samples with same device. …

Using The K-Means Clustering Algorithm To Classify Features For Choropleth Maps, Mark Polczynski, Michael Polczynski

Electrical and Computer Engineering Faculty Research and Publications

Common methods for classifying choropleth map features typically form classes based on a single feature attribute. This technical note reviews the use of the k-means clustering algorithm to perform feature classification using multiple feature attributes. The k-means clustering algorithm is described and compared to other common classification methods, and two examples of choropleth maps prepared using k-means clustering are provided.

Reliability Of Heterogeneous Distributed Computing Systems In The Presence Of Correlated Failures, Jorge E. Pezoa, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

While the reliability of distributed-computing systems (DCSs) has been widely studied under the assumption that computing elements (CEs) fail independently, the impact of correlated failures of CEs on the reliability remains an open question. Here, the problem of modeling and assessing the impact of stochastic, correlated failures on the service reliability of applications running on DCSs is tackled. The service reliability is modeled using an integrated analytical and Monte-Carlo (MC) approach. The analytical component of the model comprises a generalization of a previously developed model for reliability of non-Markovian DCSs to a setting where specific patterns of simultaneous failures in …

Speech Enhancement Using Bayesian Estimators Of The Perceptually-Motivated Short-Time Spectral Amplitude (Stsa) With Chi Speech Priors, Marek B. Trawicki, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, the authors propose new perceptually-motivated Weighted Euclidean (WE) and Weighted Cosh (WCOSH) estimators that utilize more appropriate Chi statistical models for the speech prior with Gaussian statistical models for the noise likelihood. Whereas the perceptually-motivated WE and WCOSH cost functions emphasized spectral valleys rather than spectral peaks (formants) and indirectly accounted for auditory masking effects, the incorporation of the Chi distribution statistical models demonstrated distinct improvement over the Rayleigh statistical models for the speech prior. The estimators incorporate both weighting law and shape parameters on the cost functions and distributions. Performance is evaluated in terms of the …

On The Use Of Gaussian Approximation In Analyzing The Performance Of Optical Receivers, George El-Howayek, C. Zhang, Y. Li, J. S. Ng, J. P.R. David, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

The analytical calculation of the bit error rate (BER) of digital optical receivers that employ avalanche photodiodes (APDs) is challenging due to 1) the stochastic nature of the avalanche photodiode's impulse-response function and 2) the presence of intersymbol interference (ISI). At ultrafast transmission rates, ISI becomes a dominant component of the BER, and its effect on the BER should be carefully addressed. One solution to this problem, termed the bit-pattern-dependent (PD) approach, is to first calculate the conditional BER given a specific bit pattern and then average over all possible bit patterns. Alternatively, a simplifying method, termed the bit-pattern-independent (PI) …

Thermal Tuning Of Mems Buckled Membrane Actuator Stiffness, Robert A. Lake, Kyle K. Ziegler, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

The thermal tuning characteristics of a microelectromechanical systems (MEMS) buckled membrane exhibiting regions of both positive and negative stiffness is examined and analyzed using finite element method (FEM) simulation and through experimentation. The membranes are fabricated by releasing a silicon/silicon dioxide (Si/SiO₂) laminated membrane from a silicon on insulator (SOI) wafer. The difference in thermal expansion coefficients between Si and SiO2 induces a compressive stress in the SiO₂ layer causing out-of-plane buckling of the membrane. This structure is found to have positive and negative stiffness regions when actuated with a transverse force. It is demonstrated that the …

Non-Local Model For The Spatial Distribution Of Impact Ionization Events In Avalanche Photodiodes, David A. Ramirez, Majeed M. Hayat, Andrew S. Huntington, George M. Williams

Electrical and Computer Engineering Faculty Research and Publications

We report an extension of the analytical dead space multiplication theory that provides the means to theoretically determine the spatial distribution of electron and hole impact-ionization events in an arbitrarily specified heterojunction multiplication region. The model can be used to understand the role of the dead space in regularizing the locations of impact ionization. It can also be utilized to analyze, design, and optimize new generations of ultra-low noise, multistaged gain avalanche photodiodes based upon judiciously energizing and relaxing carriers to enhance electron impact ionization and suppress hole impact ionization.

Lightweight Data Compression In Wireless Sensor Networks Using Huffman Coding, Henry P. Medeiros, Marcos C. Maciel, Richard D. Souza, Marcelo E. Pellenz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a lightweight data compression method for wireless sensor networks monitoring environmental parameters with low resolution sensors. Instead of attempting to devise novel ad hoc algorithms, we show that, given general knowledge of the parameters that must be monitored, it is possible to efficiently employ conventional Huffman coding to represent the same parameter when measured at different locations and time periods. When the data collected by the sensor nodes consists of integer measurements, the Huffman dictionary computed using statistics inferred from public datasets often approaches the entropy of the data. Results using temperature and relative humidity measurements show …

Robust And Resilient State-Dependent Control Of Continuous-Time Nonlinear Systems With General Performance Criteria, Xin Wang, Edwin E. Yaz, James Long

Electrical and Computer Engineering Faculty Research and Publications

A novel state-dependent control approach for continuous-time nonlinear systems with general performance criteria is presented in this paper. This controller is optimally robust for model uncertainties and resilient against control feedback gain perturbations in achieving general performance criteria to secure quadratic optimality with inherent asymptotic stability property together with quadratic dissipative type of disturbance reduction. For the system model, unstructured uncertainty description is assumed, which incorporates commonly used types of uncertainties, such as norm-bounded and positive real uncertainties as special cases. By solving a state-dependent linear matrix inequality at each time, sufficient condition for the control solution can be found …