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Electrical and Computer Engineering Faculty Research & Creative Works

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Comparison Of A Heuristic Dynamic Programming And A Dual Heuristic Programming Based Adaptive Critics Neurocontroller For A Turbogenerator, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2000

Comparison Of A Heuristic Dynamic Programming And A Dual Heuristic Programming Based Adaptive Critics Neurocontroller For A Turbogenerator, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a neurocontroller for a turbogenerator that augments/replaces the conventional automatic voltage regulator and the turbine governor. The neurocontroller uses a novel technique based on the adaptive critic designs with emphasis on heuristic dynamic programming (HDP) and dual heuristic programming (DHP). Results are presented to show that the DHP based neurocontroller is robust and performs better than the HDP based neurocontroller, as well as the conventional controller, especially when the system conditions and configuration changes.

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Successful Proposal Preparation, Mariesa Crow Jan 2000

Successful Proposal Preparation, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A Schooling On Their Implications For Software Engineering [Trends], Ann K. Miller Jan 2000

A Schooling On Their Implications For Software Engineering [Trends], Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

A discussion is presented on trends in software engineering. This can be done by simply extrapolating some of the popular, current trends. And, in fact, we examine a few of these obvious indicators. However, software engineering has had new approaches that are more revolutionary than evolutionary. In particular, we try to discern trends in software engineering based on trends in delivered software systems.

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Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson Dec 1999

Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Battery energy storage (BES) systems show promise of savings for both the utility and the customer. An algorithm combining multi-pass dynamic programming (MPDP) with a time-shift technique has been developed for two purposes: economic dispatch of BES and finding optimal BES power and energy capacities in a power system. Due to the daily cyclic nature of the load curve, a 168-hour load curve is decomposed into seven 24-hour subsections for easy management. Each subsection is treated independently. Decomposition can save computation time and computer memory. A time-shift technique provides better starting state values and improves the finding process of the …

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Multimedia Databases, S. R. Subramanya Dec 1999

Multimedia Databases, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

The acquisition, generation, storage and processing of multimedia data in computers and transmission over networks have grown tremendously. Databases have been developed to cope with huge amounts of data in different applications. Multimedia databases (MMDB) are essential for efficient management and effective use of this data. They are however still in their infancy. Most current MMDB system prototypes are closely bound to narrow application areas. Experiences gained from developing and using novel multimedia will help advance the multimedia database technology.

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An Accurate Method Of Neglecting Dynamic Saliency Of Synchronous Machines In Power Electronic Based Systems, Steven Pekarek, E. A. Walters Dec 1999

An Accurate Method Of Neglecting Dynamic Saliency Of Synchronous Machines In Power Electronic Based Systems, Steven Pekarek, E. A. Walters

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, motivations for neglecting dynamic saliency in the detailed models of power electronic based systems are presented, A new method of neglecting dynamic saliency is then introduced in which approximate operational impedances are derived from original dynamic salient models. New machine parameters are obtained by fitting to the approximate impedance curves, yielding model parameters in which dynamic saliency is eliminated. An example synchronous machine/converter system is provided that demonstrates the accuracy and increased simulation efficiency resulting from this technique. Therein, errors resulting from neglecting dynamic saliency are reduced from greater than 25% using traditional approximations to less than …

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Analysis And Average-Value Modeling Of An Inductorless Synchronous Machine Load Commutated Converter System, J. T. Alt, Scott D. Sudhoff, B. E. Ladd Dec 1999

Analysis And Average-Value Modeling Of An Inductorless Synchronous Machine Load Commutated Converter System, J. T. Alt, Scott D. Sudhoff, B. E. Ladd

Electrical and Computer Engineering Faculty Research & Creative Works

Synchronous machine fed load-commutated converters (SMLCCs) are commonly used for dc power sources in marine and aircraft power systems. The focus of this paper is to set forth a model for SMLCCs for use in transient stability studies involving these systems. Although there has been considerable work in this area, much of this work has assumed the existence of a dc link inductor whereupon the dc link current is approximately constant. In practice, this filter is often eliminated, whereupon previous models are no longer valid. A new average-value model is set forth for SMLCCs in which there is no dc …

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An Efficient And Accurate Method Of Representing Magnetic Saturation In Physical-Variable Models Of Synchronous Machines, Steven Pekarek, E. A. Walters, B. T. Kuhn Dec 1999

An Efficient And Accurate Method Of Representing Magnetic Saturation In Physical-Variable Models Of Synchronous Machines, Steven Pekarek, E. A. Walters, B. T. Kuhn

Electrical and Computer Engineering Faculty Research & Creative Works

When analyzing machine/converter systems it is convenient to represent the stator variables in physical (abc) form. It has recently been shown that a physical-variable voltage-behind-reactance form of the synchronous machine model can be derived which is numerically more efficient than existing physical-variable models. In this research, a new voltage-behind-reactance model is derived which incorporates the effects of magnetic saturation. This model is shown to have the same numerical efficiency of the unsaturated model and is readily implemented in either circuit-based or differential-equation based simulation languages. An example system is provided which demonstrates the accuracy and efficiency of this model for …

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Multimode Solution For The Reflection Properties Of An Open-Ended Rectangular Waveguide Radiating Into A Dielectric Half-Space: The Forward And Inverse Problems, R. Zoughi, Aaron D. Benally, Karl Joseph Bois Dec 1999

Multimode Solution For The Reflection Properties Of An Open-Ended Rectangular Waveguide Radiating Into A Dielectric Half-Space: The Forward And Inverse Problems, R. Zoughi, Aaron D. Benally, Karl Joseph Bois

Electrical and Computer Engineering Faculty Research & Creative Works

Open-ended rectangular waveguides are extensively used in nondestructive dielectric material evaluation. The dielectric properties of an infinite-half space of a material are calculated from the measured reflection properties referenced to the waveguide aperture. This calculation relies on a theoretical and numerical derivation of the reflection coefficient likewise referenced to the waveguide aperture. Most of these derivations assume the dominant mode field distribution across the waveguide aperture. However, when dealing with low permittivity and low loss dielectric materials, there may exist significant errors when calculating the dielectric properties from the measured reflection coefficient. These errors have also shown to be more …

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Dielectric Plug-Loaded Two-Port Transmission Line Measurement Technique For Dielectric Property Characterization Of Granular And Liquid Materials, K. Mubarak, R. Zoughi, Aaron D. Benally, Karl Joseph Bois, Larry F. Handjojo Dec 1999

Dielectric Plug-Loaded Two-Port Transmission Line Measurement Technique For Dielectric Property Characterization Of Granular And Liquid Materials, K. Mubarak, R. Zoughi, Aaron D. Benally, Karl Joseph Bois, Larry F. Handjojo

Electrical and Computer Engineering Faculty Research & Creative Works

There are numerous dielectric property characterization techniques available in the microwave regime each with its own uniqueness, advantages and disadvantages. The two-port completely-filled waveguide (transmission line) technique is a robust measurement approach which is well suited for solid dielectric materials. In this case, the dielectric material can be relatively easily machined to fit inside the waveguide and the subsequent measurement of the scattering parameters of this two-port device renders the dielectric properties of the material filling the waveguide. However, this technique is not well suited for measuring the dielectric properties of granular and liquid materials. These materials are used in …

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Wide-Bandwidth Multi-Resolutional Analysis Of A Surface-Mounted Pm Synchronous Machine, S. D. Sudhoff, Jerry L. Tichenor, James L. Drewniak Dec 1999

Wide-Bandwidth Multi-Resolutional Analysis Of A Surface-Mounted Pm Synchronous Machine, S. D. Sudhoff, Jerry L. Tichenor, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Advances in power semiconductor devices have led to inverters with unprecedented voltage edge rates. This has decreased inverter switching losses and enabled the use of increasingly higher switching frequencies. However, faster edge rates and higher switching frequencies increase electromagnetic compatibility (EMC) problems, machine insulation stress, bearing currents, and other aspects of system design. Typical computer simulations used to design and evaluate proposed electric drive systems cannot be used to predict these high-frequency effects. A wide-bandwidth multi-resolutional analysis that allows designers to anticipate and quantify high-frequency effects is detailed in this paper. The approach is specifically applied to permanent magnet synchronous …

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Slot And Aperture Coupling For Airflow Aperture Arrays In Shielding Enclosure Designs, Min Li, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren Aug 1999

Slot And Aperture Coupling For Airflow Aperture Arrays In Shielding Enclosure Designs, Min Li, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The coupling between apertures or slots in airflow arrays is investigated numerically by means of the method of moments (MoM). Application to shielding enclosure design is of particular interest. Justification for a previously extracted simple empirical design approach for the relation between the number N and size a of apertures, and the shielding effectiveness ∼Na3 for an airflow aperture array is given. The coupling between slots is also investigated. The application limit of the empirical design approach is demonstrated.

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Application Of A Hybrid Fem/Mom Method To A Canonical Pcb Problem, Yun Ji, J. Chen, Todd H. Hubing, James L. Drewniak Aug 1999

Application Of A Hybrid Fem/Mom Method To A Canonical Pcb Problem, Yun Ji, J. Chen, Todd H. Hubing, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid FEM/MOM method was used to solve a canonical printed circuit board (PCB) problem. The PCB is populated with three traces. One is a signal line and the other two are I/O lines that extend beyond the boundary of the board. The finite element method (FEM) was used to model the fields in the volume around the on-board trace. The method of moments (MOM) was employed to model the equivalent surface currents on the board and the current on the off-board traces. The FEM and MOM equations were coupled by forcing the continuity of tangential fields on the dielectric …

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Microstrip Coupling Algorithm Validation And Modification Based On Measurements And Numerical Modeling, Theodore M. Zeeff, Chris E. Olsen, Todd H. Hubing, James L. Drewniak, Richard E. Dubroff Aug 1999

Microstrip Coupling Algorithm Validation And Modification Based On Measurements And Numerical Modeling, Theodore M. Zeeff, Chris E. Olsen, Todd H. Hubing, James L. Drewniak, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, mutual capacitance and inductance between two coupled traces is measured and computed to validate and simplify coupling algorithms used in an expert system software package. The algorithm's applicability to common microstrip configurations is tested through comparisons between FEM based solutions, |S21| measurements and the algorithm solutions under several permutations of a test board. Adjustments to the original algorithm are proposed that reduce computation times with out significantly affecting the accuracy of the result.

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Anticipating Emi From Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Min Li, Xiao Luo, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff Aug 1999

Anticipating Emi From Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Min Li, Xiao Luo, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing speed of digital circuit design as well as the density of printed circuit board (PCB) layouts often result in more challenging electromagnetic interference (EMI) problems. The coupling between a high-speed digital line and an I/O line can be a primary EMI coupling path, and the attached cable a dominant radiator. This mechanism is studied and modeled herein in a multi-stage modeling fashion. EMI modeling is developed for coupling between the transmission lines, and the attached cable as the EMI antenna. Finally, the EMI is calculated for the coupled noise driving the attached cable. The agreement between the modeled …

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Rf Isolation Using Power Islands In Dc Power Bus Design, Jun Fan, Yong Ren, Juan Chen, David M. Hockanson, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff Aug 1999

Rf Isolation Using Power Islands In Dc Power Bus Design, Jun Fan, Yong Ren, Juan Chen, David M. Hockanson, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Power island structures are often employed for minimizing the propagation of high-frequency noise on DC power buses. The rationale is based on introducing a series impedance in the power plane to provide isolation of a noise source from the rest of the PCB design. The power island concept is investigated herein experimentally, to determine its noise mitigation attributes and limitations. A modeling approach that is suitable for arbitrary PCB island geometries including lumped SMT decoupling capacitors is also presented. The modeling and measurements indicate that island structures can achieve some degree of isolation under certain conditions.

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Signal Induced Emi In Fibre Channel Cable-Connector Assemblies, Minjia Xu, S. Radu, James L. Knighten, James L. Drewniak, Todd H. Hubing, L. O. Hoeft, J. T. Dibene Ii Aug 1999

Signal Induced Emi In Fibre Channel Cable-Connector Assemblies, Minjia Xu, S. Radu, James L. Knighten, James L. Drewniak, Todd H. Hubing, L. O. Hoeft, J. T. Dibene Ii

Electrical and Computer Engineering Faculty Research & Creative Works

The EMI performance of cable-connector assemblies designed for FC-0 transmission has been studied. Two types of cable and two connector styles were evaluated. Experimental results show that the dominant radiation mechanism for short cable lengths is the common-mode current caused by source and PCB skew that leaks to the exterior of the shield via the transfer impedance of the connector. However, the cable imbalance becomes a more significant source of common-mode current than the source skew when the cable assembly is tens of meters long.

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Emi Associated With Inter-Board Connection For Module-On-Backplane And Stacked-Card Configurations, Xiaoning Ye, Jim Nadolny, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff Aug 1999

Emi Associated With Inter-Board Connection For Module-On-Backplane And Stacked-Card Configurations, Xiaoning Ye, Jim Nadolny, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

EMI associated with inter-board connection was studied through common-mode current measurements and FDTD modeling for stacked-card and module-on-backplane configurations. Three types of connections were investigated experimentally including an open pin field connection, an "ideal" semi-rigid coaxial cable connection, and a production connector. Both microstrip and stripline signal routing on the PCB were investigated. The results indicated signal routing on the PCBs or the inter-board connection can dominate the EMI process. Several cases of connector geometries were studied using FDTD modeling and good agreement was achieved between the measured and FDTD results.

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A Blind Deconvolution Approach For Resolution Enhancement Of Near-Field Microwave Images, Ali Mohammad-Djafari, Nasser N. Qaddoumi, R. Zoughi Jul 1999

A Blind Deconvolution Approach For Resolution Enhancement Of Near-Field Microwave Images, Ali Mohammad-Djafari, Nasser N. Qaddoumi, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper we propose a blind deconvolution method to enhance the resolution of images obtained by near-field microwave nondestructive techniques using an open ended rectangular waveguide probe. In fact, we model such images to be the result of a convolution of the real input images with a point spread function (PSF). This PSF depends mainly on the dimensions of the waveguide, the operating frequency, the nature of the object under test and standoff distance between the waveguide and the object. Unfortunately, it is very difficult to model this PSF from the physical data. For this reason, we consider the …

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Power Bus Noise Reduction Using Power Islands In Printed Circuit Board Designs, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Y. Ren, Jun Fan, Richard E. Dubroff May 1999

Power Bus Noise Reduction Using Power Islands In Printed Circuit Board Designs, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Y. Ren, Jun Fan, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Power islands are often used to isolate devices that put noise on a power bus from devices that may be susceptible to power bus noise. At high frequencies however, the effectiveness of these islands depends on the implementation. This paper experimentally investigates the effectiveness of different power island structures at frequencies up to 3 GHz.

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Fdtd Modeling Of Emi Antennas, Motoshi Tanaka, Wei Cui, Xiao Luo, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff May 1999

Fdtd Modeling Of Emi Antennas, Motoshi Tanaka, Wei Cui, Xiao Luo, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The FDTD (finite-difference time-domain) method is used for modeling EMI antenna geometries to anticipate EMI problems in high-speed digital designs. FDTD is well-suited to modeling large-scale geometries such as cables that might be driven against PCB ground planes as a result of a noise voltage that appears at the connector. Three specific cases are addressed herein including a simple cable driven against a PCB ground, coupling between a high-speed digital and I/O line that drives a cable against the PCB, and the finite impedance of the PCB reference plane that results in an effective noise source that drives the PCB …

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Integrating Research Results Into A Power Engineering Curriculum, Chanan Singh, Kraig J. Olejniczak, Kevin Tomsovic, Richard D. Christie, Anil Pahwa, Kwang Y. Lee, Mariesa Crow May 1999

Integrating Research Results Into A Power Engineering Curriculum, Chanan Singh, Kraig J. Olejniczak, Kevin Tomsovic, Richard D. Christie, Anil Pahwa, Kwang Y. Lee, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents summaries of the activities of six research active power engineering educators which were presented in a panel session of the same name at the IEEE Power Engineering Society Winter Meeting on February 3, 1997 in New York City, USA. Each of the panelists discusses how research results are incorporated into courses and how students benefit from this approach.

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Routing And Scheduling I/O Transfers On Wormhole-Routed Mesh Networks, Bhagirath Narahari, Sunil Shende, Rahul Simha, S. R. Subramanya Apr 1999

Routing And Scheduling I/O Transfers On Wormhole-Routed Mesh Networks, Bhagirath Narahari, Sunil Shende, Rahul Simha, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

This paper studies the problem of routing and scheduling parallel I/O operations to minimize the time required to transfer data between processors and I/O devices. In particular, a 2-dimensional mesh architecture is considered in which routing is performed using wormhole switching and I/O nodes are placed on the periphery of the mesh. Two broad classes of data transfer mechanisms are examined: schedules with blocking (SB), in which packets may be temporarily blocked during transit, and schedules with no blocking (SNB), in which packets are never blocked in the network. For both classes, optimal scheduling is shown to be NP-complete, and …

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Neurocontrol Of Turbogenerators With Adaptive Critic Designs, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 1999

Neurocontrol Of Turbogenerators With Adaptive Critic Designs, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a neuro-controller for a turbogenerator using a novel technique based on adaptive critic designs (ACD). This adaptive critic design based neuro-controller augments/replaces the traditional automatic voltage regulator (AVR) and the turbine governor of the generator. Simulation results are presented to show that neural network controllers with the ACD have the potential to control turbogenerators when system conditions and configuration changes.

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Dynamic Re-Optimization Of A Fed-Batch Fermentor Using Heuristic Dynamic Programming, Donald C. Wunsch, M. S. Iyer Jan 1999

Dynamic Re-Optimization Of A Fed-Batch Fermentor Using Heuristic Dynamic Programming, Donald C. Wunsch, M. S. Iyer

Electrical and Computer Engineering Faculty Research & Creative Works

Traditionally, fed-batch biochemical process optimization and control uses complicated theoretical off-line optimizers, with no online model adaptation or re-optimization. This study demonstrates the applicability, effectiveness, and economic potential of a simple phenomenological model for modeling, and an adaptive critic design, heuristic dynamic programming, for online re-optimization and control of an aerobic fed-batch fermentor. The results are compared with those obtained using a heuristic random optimizer

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Microwave Oscillator With The Shielded Dielectric Resonator, Sergey Kharkovsky, A. E. Kogut, V. K. Komeenkov, V. I. Lutsenko Jan 1999

Microwave Oscillator With The Shielded Dielectric Resonator, Sergey Kharkovsky, A. E. Kogut, V. K. Komeenkov, V. I. Lutsenko

Electrical and Computer Engineering Faculty Research & Creative Works

A Gunn oscillator with partially shielded hemidisk quasioptical resonator is investigated experimentally in this paper. The investigations of the generation characteristics of oscillations by the semiconductor diode in this resonator are carried out for the different radial co-ordinates of the oscillator active element. The advantages of the investigated oscillator in comparison with the oscillator with an open dielectric resonator are shown

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Use Of Transforms For Indexing In Audio Databases, S. R. Subramanya, Abdou Youssef, Bhagirath Narahari, Rahul Simha Jan 1999

Use Of Transforms For Indexing In Audio Databases, S. R. Subramanya, Abdou Youssef, Bhagirath Narahari, Rahul Simha

Electrical and Computer Engineering Faculty Research & Creative Works

The phenomenal increases in the amounts of audio data being generated, processed and used in several computer applications have necessitated the development of audio database systems with newer features, such as content-based queries and similarity searches, to manage and use such data. Fast and accurate retrieval for content-based queries is crucial in order for such systems to be useful. Efficient content-based indexing and similarity searching schemes are keys to providing fast and relevant data retrieval. This paper studies and evaluates the different parameters involved in an indexing scheme which uses transforms (as used in signal processing) for generating the audio …

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In-Clip Search Algorithm For Content-Based Audio Retrieval, Punpiti Piamsa-Nga, Nikitas A. Alexandridis, Sanan Srakaew, George C. Blankenship, S. R. Subramanya Jan 1999

In-Clip Search Algorithm For Content-Based Audio Retrieval, Punpiti Piamsa-Nga, Nikitas A. Alexandridis, Sanan Srakaew, George C. Blankenship, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

Researchers are currently more interested in searching for fragments that are similar to a query, than a total data item that is similar to a query; the search interest is for "contains", not "is". The paper presents an O(logn) algorithm, called the "generalized virtual node (GVN)" algorithm; the GVN algorithm is a search algorithm for data fragments that have similar contents to that of a query. An example of the use of the GVN algorithm is in the search of a database of audio recordings for a few measures of a melody. Each audio clip is transformed into characteristic features …

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A Distributed Algorithm For The Classification Of Images On A Network Of Workstations, S. R. Subramanya Jan 1999

A Distributed Algorithm For The Classification Of Images On A Network Of Workstations, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

Image databases require content-based queries and retrievals. Fast and accurate retrievals for user queries depend on efficient indexing and searching schemes. The classification of images into different categories (classes) is an important task which facilitates the indexing and searching process. The classification of huge amounts of image data place enormous demands on computational requirements. Network of workstations (NOWs, also sometimes called clusters) are a cost-effective way of providing the much-needed computational power in such applications. This paper presents a distributed scheme for the classification of images in an image database, using a network of workstations. The results of the classification …

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Excitation Of The High-Q-Factor Whispering Gallery Modes In The Hemispherical Dielectric Resonator With The Cylinder Shield, Sergey Kharkovsky, V. V. Kutuzov, A. E. Kogut Jan 1999

Excitation Of The High-Q-Factor Whispering Gallery Modes In The Hemispherical Dielectric Resonator With The Cylinder Shield, Sergey Kharkovsky, V. V. Kutuzov, A. E. Kogut

Electrical and Computer Engineering Faculty Research & Creative Works

A hollow metal cylinder with a semicircle in the base is used as the shield of a hemispherical dielectric resonator with whispering gallery (WG) modes. It is shown that the spectrum of the WG modes of this resonator is clearer than the spectrum of a similar resonator with a hemispherical shield. It is determined that the high-Q-factor WG modes are excited in the proposed resonator by the coupling slot on the mirror. Their fields are localized in the dielectric. The frequency dependence of the Q-factor value is measured. A good conformity of this experimental dependence with the analytic dependence is …

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