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Full-Text Articles in Computer Engineering

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler Dec 2008

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler

Electrical and Computer Engineering Faculty Research and Publications

The dependence of the performance of separate-absorption-multiplication (SAM) single-photon avalanche diodes (SPADs) on the width of the multiplication region is theoretically investigated. The theory is applied to SAM SPADs with InP homojunction multiplication regions and InAlAs-InP heterojunction multiplication regions. In both cases the absorber layer is InGaAs. Two scenarios for the dark counts are considered: (i) low-temperature operation, when the number of dark carriers is dominated by field-assisted mechanisms of band-to-band tunneling and tunneling through defects; and (ii) room-temperature operation, when the number of dark carriers in the multiplication region is dominated by the generation/recombination mechanism. The analysis utilizes a …


A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel Dec 2008

A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel

Electrical and Computer Engineering Faculty Research and Publications

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would …


Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson Oct 2008

Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a new method for statistical estimation of Mel-frequency cepstral coefficients (MFCCs) in noisy speech signals is proposed. Previous research has shown that model-based feature domain enhancement of speech signals for use in robust speech recognition can improve recognition accuracy significantly. These methods, which typically work in the log spectral or cepstral domain, must face the high complexity of distortion models caused by the nonlinear interaction of speech and noise in these domains. In this paper, an additive cepstral distortion model (ACDM) is developed, and used with a minimum mean-squared error (MMSE) estimator for recovery of MFCC features …


Canonical Correlation Feature Selection For Sensors With Overlapping Bands: Theory And Application, Biliana S. Paskaleva, Majeed M. Hayat, Zhipeng Wang, J. Scott Tyo, Sanjay Krishna Oct 2008

Canonical Correlation Feature Selection For Sensors With Overlapping Bands: Theory And Application, Biliana S. Paskaleva, Majeed M. Hayat, Zhipeng Wang, J. Scott Tyo, Sanjay Krishna

Electrical and Computer Engineering Faculty Research and Publications

The main focus of this paper is a rigorous development and validation of a novel canonical correlation feature- selection (CCFS) algorithm that is particularly well suited for spectral sensors with overlapping and noisy bands. The proposed approach combines a generalized canonical correlation analysis framework and a minimum mean-square-error criterion for the selection of feature subspaces. The latter induces ranking of the best linear combinations of the noisy overlapping bands and, in doing so, guarantees a minimal generalized distance between the centers of classes and their respective reconstructions in the space spanned by sensor bands. To demonstrate the efficacy and the …


Distributed Object Tracking Using A Cluster-Based Kalman Filter In Wireless Camera Networks, Henry Medeiros, Johnny Park, Avinash Kak Aug 2008

Distributed Object Tracking Using A Cluster-Based Kalman Filter In Wireless Camera Networks, Henry Medeiros, Johnny Park, Avinash Kak

Electrical and Computer Engineering Faculty Research and Publications

Local data aggregation is an effective means to save sensor node energy and prolong the lifespan of wireless sensor networks. However, when a sensor network is used to track moving objects, the task of local data aggregation in the network presents a new set of challenges, such as the necessity to estimate, usually in real time, the constantly changing state of the target based on information acquired by the nodes at different time instants. To address these issues, we propose a distributed object tracking system which employs a cluster-based Kalman filter in a network of wireless cameras. When a target …


Resource-Constrained Load Balancing Controller For A Parallel Database, Z. Tang, J. Douglas Birdwell, J. Chiasson, Chaouki T. Abdallah, Majeed M. Hayat Jul 2008

Resource-Constrained Load Balancing Controller For A Parallel Database, Z. Tang, J. Douglas Birdwell, J. Chiasson, Chaouki T. Abdallah, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

This brief documents experimental results using a deterministic dynamic nonlinear system for load balancing, previously reported by Tang et al. in a cluster of computer nodes used for parallel computations in the presence of time delays and resource constraints. While previous publications by the authors have provided theoretical analysis of this load-balancing strategy using an idealized model, and have documented experiments using a simulated database, experimental results using a complete database for DNA profiles are documented here. Evaluation of the proposed load-balancing strategy using an actual database was critical because of several characteristics of the database that cannot be accurately …


Induction Machine Broken Bar And Stator Short-Circuit Fault Diagnostics Based On Three Phase Stator Current Envelopes, Aderiano M. Da Silva, Richard J. Povinelli, Nabeel Demerdash Mar 2008

Induction Machine Broken Bar And Stator Short-Circuit Fault Diagnostics Based On Three Phase Stator Current Envelopes, Aderiano M. Da Silva, Richard J. Povinelli, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

A new method for the fault diagnosis of a broken rotor bar and interturn short circuits in induction machines (IMs) is presented. The method is based on the analysis of the three-phase stator current envelopes of IMs using reconstructed phase space transforms. The signatures of each type of fault are created from the three-phase current envelope of each fault. The resulting fault signatures for the new so-called ldquounseen signalsrdquo are classified using Gaussian mixture models and a Bayesian maximum likelihood classifier. The presented method yields a high degree of accuracy in fault identification as evidenced by the given experimental results, …


Overview Of Biocreative Ii Gene Mention Recognition, Larry Smith, Lorraine K. Tanabe, Rie Johnson Nee Ando, Cheng-Ju Kuo, I-Fang Chung, Chun-Nan Hsu, Yu-Shi Lin, Roman Klinger, Christoph M. Friedrich, Kuzman Ganchev, Manabu Torii, Hongfang Liu, Barry Haddow, Craig A. Struble, Richard J. Povinelli, Andreas Vlachos, William A. Baumgartner, Lawrence Hunter, Bob Carpenter, Richard Tzong-Han Tsai, Hong-Jie Dai, Feng Liu, Yifei Chen, Chengjie Sun, Sophia Katrenko, Pieter Adriaans, Christian Blaschke, Rafael Torres, Mariana Neves, Preslav Nakov, Anna Divoli, Manuel Maña-López, Jacinto Mata, W John Wilbur Jan 2008

Overview Of Biocreative Ii Gene Mention Recognition, Larry Smith, Lorraine K. Tanabe, Rie Johnson Nee Ando, Cheng-Ju Kuo, I-Fang Chung, Chun-Nan Hsu, Yu-Shi Lin, Roman Klinger, Christoph M. Friedrich, Kuzman Ganchev, Manabu Torii, Hongfang Liu, Barry Haddow, Craig A. Struble, Richard J. Povinelli, Andreas Vlachos, William A. Baumgartner, Lawrence Hunter, Bob Carpenter, Richard Tzong-Han Tsai, Hong-Jie Dai, Feng Liu, Yifei Chen, Chengjie Sun, Sophia Katrenko, Pieter Adriaans, Christian Blaschke, Rafael Torres, Mariana Neves, Preslav Nakov, Anna Divoli, Manuel Maña-López, Jacinto Mata, W John Wilbur

Electrical and Computer Engineering Faculty Research and Publications

Nineteen teams presented results for the Gene Mention Task at the BioCreative II Workshop. In this task participants designed systems to identify substrings in sentences corresponding to gene name mentions. A variety of different methods were used and the results varied with a highest achieved F1 score of 0.8721. Here we present brief descriptions of all the methods used and a statistical analysis of the results. We also demonstrate that, by combining the results from all submissions, an F score of 0.9066 is feasible, and furthermore that the best result makes use of the lowest scoring submissions.