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Articles 1 - 14 of 14

Full-Text Articles in Biomedical Engineering and Bioengineering

Analysis And Control Theory Of Some Cochlear Models , Isaac Chepkwony Jan 2006

Analysis And Control Theory Of Some Cochlear Models , Isaac Chepkwony

Retrospective Theses and Dissertations

The standard 2-dimensional cochlear model consists of a 1-dimensional elastic structure, modeling the basilar membrane, surrounded by an incompressible 2-dimensional fluid within a 2-dimensional cochlear cavity. The dynamics are typically driven by a pressure differential across the basilar membrane transmitted through the round and oval windows (a portion of the boundary of the cochlear). First we describe a model in which the basilar membrane is modeled as an infinite array of oscillators and the fluid is described by Laplace's equation. In this setting, we show that the coupled system is approximately controllable with control acting on an arbitrary open ...


Algorithms For Enhancing Pattern Separability, Feature Selection And Incremental Learning With Applications To Gas Sensing Electronic Nose Systems , Robi Polikar Jan 2000

Algorithms For Enhancing Pattern Separability, Feature Selection And Incremental Learning With Applications To Gas Sensing Electronic Nose Systems , Robi Polikar

Retrospective Theses and Dissertations

Three major issues in pattern recognition and data analysis have been addressed in this study and applied to the problem of identification of volatile organic compounds (VOC) for gas sensing applications. Various approaches have been proposed and discussed. These approaches are not only applicable to the VOC identification, but also to a variety of pattern recognition and data analysis problems. In particular, (1) enhancing pattern separability for challenging classification problems, (2) optimum feature selection problem, and (3) incremental learning for neural networks have been investigated;Three different approaches are proposed for enhancing pattern separability for classification of closely spaced, or ...


Interaction Of Acoustic Beam With Elastic Structures , Han Zhang Jan 1997

Interaction Of Acoustic Beam With Elastic Structures , Han Zhang

Retrospective Theses and Dissertations

This thesis describes experiments and calculations performed on the interaction of acoustic beams in water and air with planar and cylindrical elastic structures. Ultrasonic reflection measurements have been used to elucidate the phenomena of guided wave generation and reradiation by selecting beam incidence at, or near, phase-matching conditions. Under these circumstances reasonant mode conversion of accoustic wave to guided wave mode energy can occur. This interaction has been studied in rubber-coated steel, aluminum, plexiglas, and graphite-epoxy composite. The acoustic coupling media used in these experiments has been either water or air;Some theoretical modeling has also been undertaken to explain ...


Medical Image Tomography: A Statistically Tailored Neural Network Approach , John Patrick Kerr Jan 1994

Medical Image Tomography: A Statistically Tailored Neural Network Approach , John Patrick Kerr

Retrospective Theses and Dissertations

In medical computed tomography (CT) the tomographic images are reconstructed from planar information collected 180∘ to 360∘ around the patient. In clinical applications, the reconstructions are typically produced using a filtered backprojection algorithm. Filtered backprojection methods have limitations that create a high percentage of statistical uncertainty in the reconstructed images. Many techniques have been developed which produce better reconstructions, but they tend to be computationally expensive, and thus, impractical for clinical use;Artificial neural networks (ANN) have been shown to be adept at learning and then simulating complex functional relationships. For medical tomography, a neural network can be trained to ...


Miniaturized Chemical Sensors For Physiological Monitoring In Space Exploration , Shelley Jean Coldiron Jan 1993

Miniaturized Chemical Sensors For Physiological Monitoring In Space Exploration , Shelley Jean Coldiron

Retrospective Theses and Dissertations

This thesis describes the development of a dual-beam, fiber optic instrument for solution-phase analysis of thin-film sensors. Colorimetric indicators are described for incorporation into porous polymeric films. The films are immobilized at the distal ends of optical fibers and yield an optical response proportional to the target analyte. In its present form, the instrument functions in an absorbance mode as a solid-state, dual-wavelength photometer and is equipped with a custom-designed microprocessor controller and data processor. The described study encompasses interdisciplinary research in the fields of biomedical engineering, synthetic organic chemistry, interfacial chemistry, materials science, and computer and electrical engineering;The ...


Effects Of Randomly Rough Surfaces On Ultrasonic Inspection , Mehmet Bilgen Jan 1993

Effects Of Randomly Rough Surfaces On Ultrasonic Inspection , Mehmet Bilgen

Retrospective Theses and Dissertations

Surface finish of an industrial part affects its ultrasonic inspection and consequently the surfaces are often machined smooth before the evaluation. Ultrasonic inspection through smooth surfaces has been well studied and understood. A theoretical basis has been established for the characterization of interior cracks, voids and inclusions, and vast amount of literature exists. However, much less is known about quantitative ultrasonic inspection of such flaws in parts with rough surfaces, e.g. machine marks or "as-cast" surfaces. A question arises "When can an industrial part with randomly rough surfaces be inspected robustly using ultrasound?" This dissertation is aimed at answering ...


Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh Jan 1991

Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh

Retrospective Theses and Dissertations

An erodible ring-shaped ocular insert containing an antibiotic (tylosin tartrate) has been developed for treatment of infectious bovine keratoconjunctivitis (IBK). Four additional tasks have been completed: (1) a test to determine the retention time of the ocular device in the eyes of the calves, (2) an in vitro test to determine the degradation characteristics of the device, (3) an in vitro study to obtain the drug release profiles of the insert, and (4) a study to compare the use of rings and a field treatment method using infected cattle;The device remained in the eyes an average of 3.92 ...


The Mordanting Of Cellulose-Acetate Rayon, Nylon, And Silk With Potassium Dichromate , Lorraine Anne Mero Jan 1946

The Mordanting Of Cellulose-Acetate Rayon, Nylon, And Silk With Potassium Dichromate , Lorraine Anne Mero

Retrospective Theses and Dissertations

No abstract provided.


I Oxidative Degradation Of Cellulose-Acetate Rayon Ii Thermal Degradation Of Some Cellulosic Textiles By Steam , Virginia Charlotte Ester Jan 1943

I Oxidative Degradation Of Cellulose-Acetate Rayon Ii Thermal Degradation Of Some Cellulosic Textiles By Steam , Virginia Charlotte Ester

Retrospective Theses and Dissertations

No abstract provided.


The Chemical Resistance Of Polyhexamethylene Adipamide , Ruth Olive Donohue Jan 1942

The Chemical Resistance Of Polyhexamethylene Adipamide , Ruth Olive Donohue

Retrospective Theses and Dissertations

No abstract provided.


Mordanting Of Wool With Salts Of Aluminum , Lois Wilna Dale Jan 1942

Mordanting Of Wool With Salts Of Aluminum , Lois Wilna Dale

Retrospective Theses and Dissertations

A comparison of the aluminum-chloride and sulfuric-acid methods for the quantitative estimation of wool in cellulosic admixtures has been made by determining their effects on the weight, ash, total sulfur, and sulfate sulfur of wool;Change in weight of wool by the aluminum-chloride method varied from -2.1 to +1.9 percent for 32 determinations which averaged -0.2 +/- 0.9 percent; for five sets of six parallel determinations the means ranged from -1.2 to +1.0 percent. Change in weight of wool by the sulfuric-acid method varied from -0.6 to +2.4 percent and averaged +0.9 ...


I Halogen As A Finish For Wool Ii Formaldehyde As A Finish For Wool Iii Comparison Of Three Textile Detergents , Florence Virginia Barr Jan 1940

I Halogen As A Finish For Wool Ii Formaldehyde As A Finish For Wool Iii Comparison Of Three Textile Detergents , Florence Virginia Barr

Retrospective Theses and Dissertations

Plain-woven cotton, regenerated-cellulose rayon, cellulose-acetate rayon, silk, wild silk, and wool were washed separately by hand in 0.5 percent solutions of neutral olive-oil soap, silicated soap, or sulfated alcohol for five minutes at room temperature, rinsed until the rinse no longer foamed and dried in air and diffused light at room temperature. After ten, twenty, thirty, forty, and fifty washings all the fabrics were analyzed for ash, percentage of light absorbed, shrinkage, wet warp breaking strength, elongation at breaking load, and weight. The silks and wool were analyzed for total nitrogen and sulfate sulfur, the wool for total sulfur ...


Oxidation, Reduction And Hydrolysis Of Wool Keratin , Mary Mildred Barr Jan 1936

Oxidation, Reduction And Hydrolysis Of Wool Keratin , Mary Mildred Barr

Retrospective Theses and Dissertations

The degradation of wool keratin by 0.25 to 7.87 N hydrochloric acid in 10 hours at 25°C and by 0.25 to 0.75 N hydrochloric acid in one hour at 100°C has been followed by weight, nitrogen, sulfur, and wet warp breaking strength of the residual keratin. Acid degradation has been shown to be much greater at 100°C than at 25°C, to remove little of the sulfur, and to decrease the wet strength more rapidly than the weight or nitrogen. The residual wool has been shown to decrease in nitrogen and increase slowly ...


The Oxidation, Reduction, And Hydrolyses Of Silk Fibroin , Eunice Chamberlin Walde Jan 1935

The Oxidation, Reduction, And Hydrolyses Of Silk Fibroin , Eunice Chamberlin Walde

Retrospective Theses and Dissertations

No abstract provided.