Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering

2006

Electrical and Computer Engineering Faculty Publications and Presentations

Articles 1 - 14 of 14

Full-Text Articles in Engineering

Oct-Based Elastography For Large And Small Deformations, Donald D. Duncan, Sean J. Kirkpatrick, Ruikang K. Wang Nov 2006

Oct-Based Elastography For Large And Small Deformations, Donald D. Duncan, Sean J. Kirkpatrick, Ruikang K. Wang

Electrical and Computer Engineering Faculty Publications and Presentations

We present two approaches to speckle tracking for optical coherence tomography (OCT)-based elastography, one appropriate for small speckle motions and the other for large, rapid speckle motions. Both approaches have certain advantages over traditional cross-correlation based motion algorithms. We apply our algorithms to quantifying the strain response of a mechanically inhomogeneous, bi-layered polyvinyl alcohol tissue phantom that is subjected to either small or large dynamic compressive forces while being imaged with a spectral domain OCT system. In both the small and large deformation scenarios, the algorithms performed well, clearly identifying the two mechanically disparate regions of the phantom. The stiffness …

Go to article

Imaging The Mechanical Stiffness Of Skin Lesions By In Vivo Acousto-Optical Elastography, Sean J. Kirkpatrick, Donald D. Duncan, Ruikang K. Wang, Molly Kulesz-Martin, Ken Lee Oct 2006

Imaging The Mechanical Stiffness Of Skin Lesions By In Vivo Acousto-Optical Elastography, Sean J. Kirkpatrick, Donald D. Duncan, Ruikang K. Wang, Molly Kulesz-Martin, Ken Lee

Electrical and Computer Engineering Faculty Publications and Presentations

Optical elastography is an imaging modality that relies on variations in the local mechanical properties of biological tissues as the contrast mechanism for image formation. Skin lesions, such as melanomas and other invasive conditions, are known to alter the arrangement of collagen fibers in the skin and thus should lead to alterations in local skin mechanical properties. We report on an acousto-optical elastography (AOE) imaging modality for quantifying the mechanical behavior of skin lesions. The method relies upon stimulating the tissue with a low frequency acoustic force and imaging the resulting strains in the tissue by means of quantifying the …

Go to article

Covariance Searches For Ncrna Gene Finding, Jennifer A. Smith Sep 2006

Covariance Searches For Ncrna Gene Finding, Jennifer A. Smith

Electrical and Computer Engineering Faculty Publications and Presentations

The use of covariance models for non-coding RNA gene finding is extremely powerful and also extremely computationally demanding. A major reason for the high computational burden of this algorithm is that the search proceeds through every possible start position in the database and every possible sequence length between zero and a user-defined maximum length at every one of these start positions. Furthermore, for every start position and sequence length, all possible combinations of insertions and deletions leading to the given sequence length are searched. It has been previously shown that a large portion of this search space is nowhere near …

Go to article

A Study Of Finite State Machine Coding Styles For Implementation In Fpgas, Nader I. Rafla, Brett L. Davis Aug 2006

A Study Of Finite State Machine Coding Styles For Implementation In Fpgas, Nader I. Rafla, Brett L. Davis

Electrical and Computer Engineering Faculty Publications and Presentations

Finite State Machines (FSM), are one of the more complex structures found in almost all digital systems today. Hardware Description Languages are used for high-level digital system design. VHDL (VHSIC Hardware Description Language) provides the capability of different coding styles for FSMs. Therefore, a choice of a coding style is needed to achieve specific performance goals and to minimize resource utilization for implementation in a re-configurable computing environment such as an FPGA. This paper is a study of the tradeoffs that can be made by changing coding styles. A comparative study on three different FSM coding styles is shown to …

Go to article

A Genetic Algorithms Approach To Non-Coding Rna Gene Searches, Jennifer A. Smith Jul 2006

A Genetic Algorithms Approach To Non-Coding Rna Gene Searches, Jennifer A. Smith

Electrical and Computer Engineering Faculty Publications and Presentations

A genetic algorithm is proposed as an alternative to the traditional linear programming method for scoring covariance models in non-coding RNA (ncRNA) gene searches. The standard method is guaranteed to find the best score, but it is too slow for general use. The observation that most of the search space investigated by the linear programming method does not even remotely resemble any observed sequence in real sequence data can be used to motivate the use of genetic algorithms (GAs) to quickly reject regions of the search space. A search space with many local minima makes gradient decent an unattractive alternative. …

Go to article

Accelerated Non-Coding Rna Searches With Covariance Model Approximations, Jennifer A. Smith Jul 2006

Accelerated Non-Coding Rna Searches With Covariance Model Approximations, Jennifer A. Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Covariance models (CMs) are a very sensitive tool for finding non-coding RNA (ncRNA) genes in DNA sequence data. However, CMs are extremely slow. One reason why CMs are so slow is that they allow all possible combinations of insertions and deletions relative to the consensus model even though the vast majority of these are never seen in practice. In this paper we examine reduction in the number of states in covariance models. A simplified CM with reduced states which can be scored much faster is introduced. A comparison of the results of a full CM versus a reduced-state model found …

Go to article

A Simple Project Paradigm For Teaching Computer Architecture, Yul Chu Jun 2006

A Simple Project Paradigm For Teaching Computer Architecture, Yul Chu

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a teaching method for a possible computer architect by using a simple DCT project for an undergraduate-level computer architecture course. The goal of the project is to let students (two or three students per team) understand the concept of computer hardware and how to design a simple RISC-type 32-bit Instruction Set Architecture (ISA). The project consists of three different tasks: 1) D (Design) - Designing a processor at the abstract level; 2) C (Code) - Writing a simulation program for the ISA; and 3) T (Test) - Running a test program to verify each function of computer …

Go to article

Dial 2004 Working Group Report On Acquisition Quality Control, Elisa H. Barney Smith, Henry Baird, William Barrett, Frank Le Bourgeois, Xiaofan Lin, George Nagy, Steve Simske Apr 2006

Dial 2004 Working Group Report On Acquisition Quality Control, Elisa H. Barney Smith, Henry Baird, William Barrett, Frank Le Bourgeois, Xiaofan Lin, George Nagy, Steve Simske

Electrical and Computer Engineering Faculty Publications and Presentations

This report summarizes the discussions of the Working Group on Acquisition Quality at the International Workshop on Document Image Analysis for Libraries, Palo Alto, CA, 23-24 January 2004. Acquisition of the image is one of the most time intensive components of forming a digital library, and the quality of the acquisition will affect all later stages of the digital library project. The current state of the art in acquisition is analyzed. Problems and suggested improvements for image acquisition and storage formats and the special problems associated with acquisition from microfilm follows. A list of general suggestions was developed which was …

Go to article

Emotion-Mapped Robotic Facial Expressions Based On Philosophical Theories Of Vagueness, Phil Serchuk, Ehud Sharlin, Martin Lukac, Marek Perkowski Feb 2006

Emotion-Mapped Robotic Facial Expressions Based On Philosophical Theories Of Vagueness, Phil Serchuk, Ehud Sharlin, Martin Lukac, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

As the field of robotics matures robots will need some method of displaying and modeling emotions. One way of doing this is to use a human-like face on which the robot can make facial expressions corresponding to its emotional state. Yet the connection between a robot s emotional state and its physical facial expression is not an obvious one: while a smile can gradually increase or decrease in size, there is no principled method of using boolean logic to map changes in facial expressions to changes in emotional states. We give a philosophical analysis of the problem and show that …

Go to article

Psf Estimation By Gradient Descent Fit To The Esf, Elisa H. Barney Smith Jan 2006

Psf Estimation By Gradient Descent Fit To The Esf, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Calibration of scanners and cameras usually involves measuring the point spread function (PSF). When edge data is used to measure the PSF, the differentiation step amplifies the noise. A parametric fit of the functional form of the edge spread function (ESF) directly to the measured edge data is proposed to eliminate this. Experiments used to test this method show that the Cauchy functional form fits better than the Gaussian or other forms tried. The effect of using a functional form of the PSF that differs from the true PSF is explored by considering bilevel images formed by thresholding. The amount …

Go to article

Partitioning Of The Degradation Space For Ocr Training, Elisa H. Barney Smith, Tim Andersen Jan 2006

Partitioning Of The Degradation Space For Ocr Training, Elisa H. Barney Smith, Tim Andersen

Electrical and Computer Engineering Faculty Publications and Presentations

Generally speaking optical character recognition algorithms tend to perform better when presented with homogeneous data. This paper studies a method that is designed to increase the homogeneity of training data, based on an understanding of the types of degradations that occur during the printing and scanning process, and how these degradations affect the homogeneity of the data. While it has been shown that dividing the degradation space by edge spread improves recognition accuracy over dividing the degradation space by threshold or point spread function width alone, the challenge is in deciding how many partitions and at what value of edge …

Go to article

Thermo-Mechanical Characterization Of Copper Through-Wafer Interconnects, Peter A. Miranda, Amy J. Moll Jan 2006

Thermo-Mechanical Characterization Of Copper Through-Wafer Interconnects, Peter A. Miranda, Amy J. Moll

Electrical and Computer Engineering Faculty Publications and Presentations

Copper through wafer interconnects (TWIs) have become a viable solution to providing interconnectivity between stacked die. In a world where minimizing chip real estate while increasing functionality is the goal for further miniaturization of electronics, TWIs hold a key role as new packaging schemes become critical for overall higher density. Little is known, however, about the impacts of mismatched coefficients of thermal expansion (CTEs) inherent to the materials used in their construction. CTE differences, if left unresolved, can pose reliability issues during TWI operation. This research focuses on providing insight into the stress levels experienced by TWI materials through finite …

Go to article

Propagation Loss Of Line-Defect Photonic Crystal Slab Waveguides, Wan Kuang, Woo J. Kim, Adam Mock, John O'Brien Jan 2006

Propagation Loss Of Line-Defect Photonic Crystal Slab Waveguides, Wan Kuang, Woo J. Kim, Adam Mock, John O'Brien

Electrical and Computer Engineering Faculty Publications and Presentations

Photonic crystal slab waveguides are created by inserting a linear defect in two-dimensional (2-D) periodic dielectric structures of finite height. Photonic crystals provide 2-D in-plane bandgaps through which light cannot propagate, however, the fact that the waveguide modes must be index-confined in the vertical direction implies that the propagation loss is strongly dependent on the out-of-plane radiation loss. We present a fully three-dimensional finite-difference time-domain numerical model for calculating the out-of-plane radiation loss in photonic crystal slab waveguides. The propagation loss of the single-line defect waveguide in 2-D triangular lattice photonic crystals is calculated for suspended membranes, oxidized lower claddings, …

Go to article

An Unsupervised Fluoroscopic Analysis Of Knee Joint Kinematics, Charles Scott, Elisa H. Barney Smith Jan 2006

An Unsupervised Fluoroscopic Analysis Of Knee Joint Kinematics, Charles Scott, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Knowledge of the three dimensional positions of bones at a joint as a function of time is required to accurately model joint kinematics. 3-D bone geometry data from a static computer tomography (CT) images can be combined with time sequence information from 2-D video fluoroscopy images to produce 3-D position data over time. The process involves creating virtual X-rays from the CT image through digitally reconstructed radiograph (DRR) projections. Historically, the process of matching the 3-D and 2-D data has required human interaction. We have eliminated the need for manual initialization using a Monte Carlo technique with a variable search …

Go to article