Engineering Commons^™

Implementation Of An Underwater Digital Acoustic Telemetry Reciever, Raymond A. Mcavoy

Electronic Theses and Dissertations

This thesis presents the design and software implementation of an underwater acoustic modem receiver. Communication links in underwater environments face several undesired effects. These include multipath signal reflections, intersymbol interference, and channel fading. This receiver design uses a combination of time and spatial diversity inputs combined with an adaptive feedback equalizer to counteract those effects. The design is based on three modules. A front-end module demodulates and Doppler-compensates the incoming data. A channel combiner module receives data from one or more front ends for spatial diversity and combines repeated transmissions for time diversity. The data from each input channel is …

Multiband Analog-To-Digital Conversion, Scott Saucier

Electronic Theses and Dissertations

The current trend in the world of digital communications is the design of versatile devices that may operate using several different communication standards in order to increase the number of locations for which a particular device may be used. The signal is quantized early on in the reciever path by Analog-to-Digital Converters (ADCs), which allows the rest of the signal processing to be done by low complexity, low power digital circuits. For this reason, it is advantageous to create an architecture that can quantize different bandwidths at different frequencies to suit several different communication protocols. This thesis outlines the design …

Current Voltage Characteristics Of A Semiconductor Metal Oxide Sensor., Huilin Ren

Electronic Theses and Dissertations

The current versus voltage (IN) characteristics of undoped and gold doped W03 thin film sensors were studied both experimentally and theoretically. A simplified equivalent circuit was formulated for the W03 sensor. It includes forward and reverse biased Schottky diodes which represent the contact region between the electrodes and the film and a resistor which represent the sum of crystallite resistance and the intercrystallite resistance between the individual crystallites. According to the electron transport mechanisms through the Metal Semiconductor (MIS) boundaries and intercrystallite boundaries, two kinds of yV and corresponding ResistanceNoltage(RN)characteristics are possible, one based on thermionic emission theory and the …

The Development Of A New Anemometer For Measuring High Speed Winds On Mount Washington, New Hampshire, Mark W. Thoren

Electronic Theses and Dissertations

Mount Washington, NH is well known as the "Home of the Worlds Worst Weather." Winds on the mountain regularly exceed 100 miles per hour, the record being 231 mph on April 12, 1934. There is a long history of weather observation on the mountain that has included various recording techniques. Until recently, the primary means of recording data has been paper strip charts. This project represents significant improvements to the Observatory's instrumentation system. Measuring windspeed on Mount Washington presents a number of design challenges. Any instruments directly exposed to the weather must be very durable. Fortunately this problem had been …

A Dynamic Parameter Tuning Algorithm For Rbf Neural Networks, Junxu Li

Electronic Theses and Dissertations

The objective of this thesis is to present a methodology for fine-tuning the parameters of radial basis function (RBF) neural networks, thus improving their performance. Three main parameters affect the performance of an RBF network. They are the centers and widths of the RBF nodes and the weights associated with each node. A gridded center and orthogonal search algorithm have been used to initially determine the parameters of the RBF network. A parameter tuning algorithm has been developed to optimize these parameters and improve the performance of the RBF network. When necessary, the recursive least square solution may be used …

Close Range 3-D Position Sensing Using Stereo Vision And Point-Of-Correspondence Through Mathematical Morphology, Mohamed T. Boraie

Electronic Theses and Dissertations

In this thesis, a procedure for calibrating 2 CCD cameras for the purpose of close-range position sensing will be introduced. The procedure results in an over-determined set of linear algebraic equations that can be utilized in determining the coordinate position of some identifiable feature in the scene relative to any set of orthogonal axes.The proposed approach relaxes the geometrical constraint required by most of the available procedures. The performance will then be evaluated and both accuracy and repeatability will be examined.For the purpose of determining the feature position in a multi-feature image, the point-of-correspondence problem will be discussed and a …

A Charge Simulation Based Computer-Aided Design Implementation Of High Voltage Systems Modelling, Hanafy Mahmoud Ismail

Electronic Theses and Dissertations

A Charge Simulation based Computer-Aided Design (CAD) Package which facilitates the development of a charge simulation model for high voltage (HV) systems consisting of a number of electrodes and one or two dielectric regions has been developed. The package calculates the potential and electric field distributions for practical systems. It avoids the necessity for creating individual programs for each system studied by allowing the geometry to be specified using a minimum of entered data. The application of the CAD package to several electrode systems which have analytical solutions is presented. Good agreement, generally within 0.5% was found between the fields …

Dsign Of I-D Recursive Digital Filters With Linear Phase Using Two All-Pass Filters With/Without Integer Coefficients, Yoon Ho Kim

Electronic Theses and Dissertations

Digital signal processing is becoming increasingly important, and is finding applications in speech processing and telecommunications in the area of 1-D signal processing. One of the important branches 1n digital signal processing 1s digital filtering.

Among the numbers of structure of digital filters, the recursive(IIR) filter is known for its computational efficiency compared to the FIR counterparts.

In this thesis, an alternative approach to the direct design of 1-D recursive digital filters satisfying prescribed magnitude specifications with or without constant group delay characteristic using two all-pass filters is presented. It is known that, by this approach, the most computationally efficient …

Coordination Of Power System Auxillary Controllers For Damping Torsional Oscillations, Rizk Mohamed El-Sayed Hamouda

Electronic Theses and Dissertations

Technical advantages of coordinating thyristor controlled static V Ar compensators (SVC) and power system stabilizers (PSS) of turbo-generator excitation systems for the stability enhancement of an AC system during small signal dynamics are presented. The technical feasibility of the coordinated SVC-PSS scheme for simultaneous damping of the inertial and the torsional oscillatory modes in a series compensated ac system is demonstrated. The investigations show that the coordinated scheme not only increases the overall system damping, but also prevents the undesirable interactions between the oscillatory modes. New control schemes for the SVC and the PSS, based on multi-input control systems which …

Design And Applications Of A Graphics Package For The Hp1000 Computer., Hsiao-Chih George Lee

Electronic Theses and Dissertations

The objective of this thesis is to develop the FORTRAN subroutine PLOTER which is a general-purpose plotting tool to plot charts on a Hewlett Packard plotter. The programs RESP and INVLAP which can plot the frequency and time responses of system functions are modified to adopt the PLOTER subroutine and are stored of the HP1000-A900 minicomputer whose software, the GRAPHICS/1000, supports the graphics ability of PLOTER. This thesis describes the theories, functions, software techniques and operations of the PLOTER subroutine and the application programs RESP and the INVLAP. It also provides program listings and example plots.

A Loran-C Antenna Coupling Unit., Timothy Andrew Reilly 1963-

Electronic Theses and Dissertations

This project is the design of an antenna-coupling unit (ACU) that will operate with the Texas Instruments LORAN-C receiver and a 28-inch antenna. The height of the antenna used at the present is eight feet. Since the application of LORAN-C positioning is being expanded to vehicular location, an eight-foot antenna is not practical. The shorter antenna is necessary to prohibit striking trees, overpasses, etc. The newly designed ACU has more voltage gain to compensate for the attenuation of the incoming signal due to the shortening of the antenna. It also has a bandpass of 90 KHz-110 KHz with the center …

A Master Clock For The Speed School Impulse Clock System Using Wwv Time Information, John E. Pfeifer Jr.

Electronic Theses and Dissertations

Since approximately February of 1979, the Speed School impulse clock system has not functioned due to a worn-out master clock that was never replaced because of a lack of fund. For this thesis project, a solid-state master clock that performs the same functions as the old mechanical master clock was built for less than $200. The new clock features accuracy traceable to the National Bureau of Standards, automatic reset after a power-down and subsequent power-up, and a daylight savings time provision. A decoder that recovers time information broadcast by radio station WWV from Fort Collins, Colorado was built and interfaced …

Application Analysis Of A Cellular Geographic Information System, Michael Edward Wehde

Electronic Theses and Dissertations

AREAS, the Area REsource Analysis System, was developed by the author as an analytical tool for resource data manipulation in a spatial context. The data base and processing software design factors relevant to economical application are reviewed. The investigation seeks to define a procedure for selection and justification of the grid cell size used to quantify the spatial domain. The performance of a cellular information system is measured in terms of mapping and inventory accuracy. These measures of performance are evaluated for various cellularizations of a single map. The interboundary distance distribution is justified as the only unique characterization of …

Audio Triamplification System., John James Mccure

Electronic Theses and Dissertations

This thesis is for the purpose of determining if active filters are useful as audio crossover networks and in particular if they are better than passive crossover networks. An entire audio reproduction system was constructed with the express design intent of linear operation in two separate modes. These two modes being, first, a conventional single power amplifier passive crossover system, and second, an active filter triamplification system. Both systems were subjected to three different objective tests and one subjective test. The subjective testing included a wide spectrum of listeners ranging from rank amateurs to highly trained recording and mixing engineers. …

Dynamic Thermal Responses Of Fluidized Beds, James Reid Pfafflin

Electronic Theses and Dissertations

Investigations were conducted on the dynamic thermal responses of fluidized beds to changes in fluidized bed parameters. Dynamic thermal responses were characterized by the time constant in the first order exponential model of temperature response with time. Bed materials, bed particle size and reactor column size were varied over a· fairly wide range. Differences were found between the active (heating) and passive (cooling) time constants under otherwise identical conditions. It was found that time constants decay in an exponential manner with increasing superficial velocity. Models are presented for prediction of time constants, based on characteristics of the fluidized bed. Models …

Screening Electrocardiograms Using Hotelling's Method Of Principle Components, Edward G. Schwartz

Electronic Theses and Dissertations

Considerable use is presently being made of computers to classify electrocardiograms (ECGs) into various heart defect categories. An example of such a program is the "Electrocardiographic Analysis Program" developed jointly by the Mayo Clinic and IBM. In one of Dr. Caceres published reports, he tells of using a computer program which involves 5,000 instructions. Dr. Caceres does not say whether this is a commercial program or one of bis own. His description does place this program in the same general category as IBM's. These programs have the common criteria of examining the ECG for the same information that a cardiologist …