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2005

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Articles 2671 - 2700 of 3074

Full-Text Articles in Engineering

Complex System Transformation: A System Of Systems Engineering (Sose) Perspective, Charles B. Keating, Andres Sousa-Poza, Samuel Kovacic Jan 2005

Complex System Transformation: A System Of Systems Engineering (Sose) Perspective, Charles B. Keating, Andres Sousa-Poza, Samuel Kovacic

Engineering Management & Systems Engineering Faculty Publications

The purpose of this paper is to develop a perspective for complex system transformation from a System of Systems Engineering (SoSE) viewpoint. This is a first attempt to make explicit a SoSE viewpoint on complex system transformation. As such, the formulation is intended to escalate the dialog and integrate the current state of understanding with respect to the nature, utility, and implications of complex system transformation in SoSE terms. To achieve our purpose we will: (1) present a short introduction that provides an essential background for SoSE, (2) provide five fundamental systems concepts that underlie a SoSE perspective of complex …

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Managing The Transformation Of System Of Systems Engineering, Samuel F. Kovacic, Andres Sousa-Poza Jan 2005

Managing The Transformation Of System Of Systems Engineering, Samuel F. Kovacic, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

SOSE methodologies exist that support engineering difficult and disparate systems with a technical solution. However, from literature it is apparent that there is a need for a formal methodology and methods that govern engineering of System of Systems (SOS) beyond the technical solution. This paper presents some of the current thinking being undertaken at NCSOSE (National Centers for Systems of Systems Engineering), on what is driving the development of SOSE, and a hypothesized solution to this problem. The purpose is to offer a different approach for resolving complexity within a situation. The paper concludes with an initial derivative of a …

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Family Of Compaction Curves For Chemically Modified Soils, Radha Krishna Daita, Vincent P. Drnevich, Daehyeon Kim Jan 2005

Family Of Compaction Curves For Chemically Modified Soils, Radha Krishna Daita, Vincent P. Drnevich, Daehyeon Kim

JTRP Technical Reports

Lime and Lime Kiln Dust (LKD) are widely used for modifying/stabilizing pavement subgrades. The addition of lime or LKD involves chemical processes that are dependent on many parameters. For natural subgrades, quality control is based on moisture and unit weight requirements using manual interpolations of one-point test data on a family of curves. For modified soils, moisture and unit weight measurements are insufficient for quality control and other tests must be considered. Various possible quality control methods for LKD-modified subgrades were evaluated. This research produced an Excel-based program to automate the generation of a family of curves and one-point data …

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Modelling And Control Of A Suspension System For Vehicle Applications, Padraig Dowds, Aidan O'Dwyer Jan 2005

Modelling And Control Of A Suspension System For Vehicle Applications, Padraig Dowds, Aidan O'Dwyer

Conference papers

This paper discusses the modelling of passive and active suspension systems in a car, and the subsequent design of appropriate feedback controllers for the active suspension system. The models will be investigated using a quarter car model and a full car model approach.

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A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer Jan 2005

A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer

Conference papers

An extensive literature exists on the compensation of time delayed processes. These compensation methods may be broadly divided into parameter optimised controllers, in which the controller parameters are adapted to the controller structure (the most common such controller is the proportional integral derivative, or PID, controller), and structurally optimised controllers, in which the controller structure and parameters are adapted optimally to the structure and parameters of the process model. Important structurally optimised compensator strategies are the Smith predictor and its variations. The purpose of this paper is to extract the essence of the developments in design, tuning and implementation of …

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Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Yue Zhang, Aidan O'Dwyer Jan 2005

Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Yue Zhang, Aidan O'Dwyer

Conference papers

All process investigations should start by a determination of the process model. The modeling strategy used will influence the value of the model parameters, which will in turn affect the controller values determined from tuning rules. This paper will describe an analytical method to identify a model of the dynamic characteristics of a process with a delay by using a tangent and point method, as originally suggested by Murrill, 1967. The methodology has been applied to eight benchmark transfer functions suitable for testing PID controllers, as suggested by Åström and Hägglund, 2000. The main advantages of the modeling approach are …

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Comparative Study Of Two Techniques For Determining Critical Frequency Response Characteristics, Niall O'Connor, Aidan O'Dwyer Jan 2005

Comparative Study Of Two Techniques For Determining Critical Frequency Response Characteristics, Niall O'Connor, Aidan O'Dwyer

Conference papers

The paper presents a review of a comparative study of two separate techniques for obtaining important frequency and time domain characteristics of a system consisting of a process in series with a PI/PID controller in closed loop. The first technique involves the use of a Pseudo Random Binary Sequence (PRBS) to obtain the closed loop frequency response of the system. This closed loop frequency information may then be manipulated to obtain both open loop frequency response information and process model parameters. A further mathematical simulation using Matlab may then be performed independent of the actual process in order to obtain …

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Pid Control: The Early Years, Aidan O'Dwyer Jan 2005

Pid Control: The Early Years, Aidan O'Dwyer

Conference papers

This contribution outlines controller developments 1788 – c.1900; 1900-1950: The role of instrument companies; early theoretical description of the PID controller; early tuning of the PID controller; some further developments since 1950; some conclusions.

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Dual-Band Monopole Antenna With Stagger-Tuned Arms For Broadbanding, Max Ammann, R. Farrell Jan 2005

Dual-Band Monopole Antenna With Stagger-Tuned Arms For Broadbanding, Max Ammann, R. Farrell

Conference papers

The paper describes a dual-band miniaturized printed monopole for integration in modern wireless systems. The printed monopole is augmented with two arms, resonant at slightly different frequencies, providing a broadened response for the upper band. The achieved bandwidth for the high band is 36%. These antennas are proposed for the emerging dual-mode multi-band WLAN transceivers, which operate over a wide range of bands as dictated by national authorities. Measured and simulated data, including return loss, antenna gain and radiation patterns, are presented. The numerical method employed was the finite integration technique.

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The Administration Of Senior Design Projects In A Distance Learning Environment, Isaac L. Flory Iv, John R. Hackworth Jan 2005

The Administration Of Senior Design Projects In A Distance Learning Environment, Isaac L. Flory Iv, John R. Hackworth

Engineering Technology Faculty Publications

A method for administering a senior level capstone design course in Electrical Engineering Technology in a distance learning environment is described. Several avenues are explored that help the students successfully conceive, develop, and present their design projects from off- campus locations that are consistent with the requirements placed upon their on-campus peers. Several problems that are unique to offering a senior project course in a distance learning environment are explored and solutions are described.

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Derivation Of A Closed-Form Approximate Expression For The Self-Capacitance Of A Printed Circuit Board Trace, Todd H. Hubing, Hwan-Woo Shim Jan 2005

Derivation Of A Closed-Form Approximate Expression For The Self-Capacitance Of A Printed Circuit Board Trace, Todd H. Hubing, Hwan-Woo Shim

Electrical and Computer Engineering Faculty Research & Creative Works

The electric fields that couple traces on printed circuit boards to attached cables can generate common-mode currents that result in significant radiated emissions. Previous work has shown that these radiated emissions can be estimated based on the self-capacitances of the microstrip structures on a board . In general, the determination of these self-capacitances must be done numerically using three-dimensional static modeling software. In this paper, an approximate closed-form expression for the self-capacitance of microstrip traces is derived. This expression can be used to estimate the voltage-driven common-mode emissions from boards with various microstrip trace geometries. The expression also provides insight …

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Genetic Algorithms Based Economic Dispatch With Application To Coordination Of Nigerian Thermal Power Plants, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu, Y. K. Shu'aibu Jan 2005

Genetic Algorithms Based Economic Dispatch With Application To Coordination Of Nigerian Thermal Power Plants, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu, Y. K. Shu'aibu

Electrical and Computer Engineering Faculty Research & Creative Works

The main focus of this paper is on the application of genetic algorithm (GA) to search for an optimal solution to a realistically formulated economic dispatch (ED) problem. GA is a global search technique based on principles inspired from the genetic and evolution mechanism observed in natural biological systems. A major drawback of the conventional GA (CGA) approach is that it can be time consuming. The micro-GA (µGA) approach has been proposed as a better time efficient alternative for some engineering problems. The effectiveness of CGA and µGA. to solving ED problem is initially verified on an IEEE 3-generating unit, …

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Mlp/Rbf Neural-Networks-Based Online Global Model Identification Of Synchronous Generator, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

Mlp/Rbf Neural-Networks-Based Online Global Model Identification Of Synchronous Generator, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares the performances of a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN) for online identification of the nonlinear dynamics of a synchronous generator in a power system. The computational requirement to process the data during the online training, local convergence, and online global convergence properties are investigated by time-domain simulations. The performances of the identifiers as a global model, which are trained at different stable operating conditions, are compared using the actual signals as well as the deviation signals for the inputs of the identifiers. Such an online-trained identifier with fixed optimal …

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Model For Estimating Radiated Emissions From A Printed Circuit Board With Attached Cables Due To Voltage-Driven Sources, Todd H. Hubing, Hwan-Woo Shim Jan 2005

Model For Estimating Radiated Emissions From A Printed Circuit Board With Attached Cables Due To Voltage-Driven Sources, Todd H. Hubing, Hwan-Woo Shim

Electrical and Computer Engineering Faculty Research & Creative Works

Common-mode currents induced on cables attached to printed circuit boards (PCBs) can be a significant source of unintentional radiated emissions. This paper develops a model for estimating the amount of common-mode cable current that can be induced by the signal voltage on microstrip trace structures or heatsinks on a PCB. The model employs static electric field solvers or closed-form expressions to estimate the effective self-capacitances of the board, trace, and/or heatsink. These capacitances are then used to determine the amplitude of an equivalent common-mode voltage source that drives the attached cables. The model shows that these voltage-driven common-mode cable currents …

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Robust Resource Allocations In Parallel Computing Systems: Model And Heuristics, V. Shestak, Shoukat Ali, Howard Jay Siegel, A. A. Maciejewski Jan 2005

Robust Resource Allocations In Parallel Computing Systems: Model And Heuristics, V. Shestak, Shoukat Ali, Howard Jay Siegel, A. A. Maciejewski

Electrical and Computer Engineering Faculty Research & Creative Works

The resources in parallel computer systems (including heterogeneous clusters) should be allocated to the computational applications in a way that maximizes some system performance measure. However, allocation decisions and associated performance prediction are often based on estimated values of application and system parameters. The actual values of these parameters may differ from the estimates; for example, the estimates may represent only average values, the models used to generate the estimates may have limited accuracy, and there may be changes in the environment. Thus, an important research problem is the development of resource management strategies that can guarantee a particular system …

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Simulation-Based Performance Modeling For War Fighter In Loop Minefield Detection System, Abhilash Rajagopal, Sanjeev Agarwal, Sreeram Ramakrishnan Jan 2005

Simulation-Based Performance Modeling For War Fighter In Loop Minefield Detection System, Abhilash Rajagopal, Sanjeev Agarwal, Sreeram Ramakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Using An Lu Recombination Method To Improve The Performance Of The Boundary Element Method At Very Low Frequencies, Haixin Ke, Todd H. Hubing Jan 2005

Using An Lu Recombination Method To Improve The Performance Of The Boundary Element Method At Very Low Frequencies, Haixin Ke, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Many numerical electromagnetic modeling techniques that work very well at high frequencies do not work well at lower frequencies. This is directly or indirectly due to the weak coupling between the electric and magnetic fields at low frequencies. One technique for improving the performance of boundary element techniques at low frequencies is through the use of loop-tree basis functions, which decouple the contributions from the vector and scalar electric potential. However, loop-tree basis functions can be difficult to define for large, complex geometries. This paper describes a new method for improving the low-frequency performance of boundary element techniques. The proposed …

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Wide Area Power System Protection Using A Learning Vector Quantization Network, Ganesh K. Venayagamoorthy, Mahyar Zarghami Jan 2005

Wide Area Power System Protection Using A Learning Vector Quantization Network, Ganesh K. Venayagamoorthy, Mahyar Zarghami

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a wide area monitoring and protection technique based on a learning vector quantization (LVQ) neural network. Phasor measurements of the power network buses are monitored continuously by a LVQ network in order to alert the control room operators of possible faults. The proposed scheme could be used in a wide area monitored network to provide remedial action when primary local protection schemes for transmission lines fail to function. This technique could also be extended to the actuation of the secondary protection schemes, hence, preserving the integrity of the power network especially when the faults are spreading over …

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A Dynamic Recurrent Neural Network For Wide Area Identification Of A Multimachine Power System With A Facts Device, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

A Dynamic Recurrent Neural Network For Wide Area Identification Of A Multimachine Power System With A Facts Device, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Multilayer perceptron and radial basis function neural networks have been traditionally used for plant identification in power systems applications of neural networks. While being efficient in tracking the plant dynamics in a relatively small system, their performance degrades as the dimensions of the plant to be identified are increased, for example in supervisory level identification of a multimachine power system for wide area control purposes. Recurrent neural networks can deal with such a problem by modeling the system as a set of differential equations and with less order of complexity. Such a recurrent neural network identifier is designed and implemented …

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A Measure Of Robustness Against Multiple Kinds Of Perturbations, Shoukat Ali, Behdis Eslamnour Jan 2005

A Measure Of Robustness Against Multiple Kinds Of Perturbations, Shoukat Ali, Behdis Eslamnour

Electrical and Computer Engineering Faculty Research & Creative Works

Parallel and distributed heterogeneous computing systems may operate in an environment that undergoes unpredictable changes causing certain system performance features to degrade. Such systems need robustness to guarantee limited degradation despite fluctuations in the behavior of its component parts or environment. Our previous work in this area presented a method for generating a measure of robustness for a given system. However, the focus of that approach was on a scenario where all perturbations were of the same kind, e.g., all perturbations were in message sizes or computation times, but not both message sizes and computation times. This paper gives an …

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A Neural Network Based Optimal Wide Area Control Scheme For A Power System, Ganesh K. Venayagamoorthy, Swakshar Ray Jan 2005

A Neural Network Based Optimal Wide Area Control Scheme For A Power System, Ganesh K. Venayagamoorthy, Swakshar Ray

Electrical and Computer Engineering Faculty Research & Creative Works

With deregulation of the power industry, many tie lines between control areas are driven to operate near their maximum capacity, especially those serving heavy load centers. Wide area control systems (WACSs) using wide-area or global signals can provide remote auxiliary control signals to local controllers such as automatic voltage regulators, power system stabilizers, etc to damp out inter-area oscillations. This paper presents the design and the DSP implementation of a nonlinear optimal wide area controller based on adaptive critic designs and neural networks for a power system on the real-time digital simulator (RTDS©). The performance of the WACS as a …

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A Neural Network Based Wide Area Monitor For A Power System, Xiaomeng Li, Ganesh K. Venayagamoorthy Jan 2005

A Neural Network Based Wide Area Monitor For A Power System, Xiaomeng Li, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

With the deregulation of power industry, many tie lines between control areas are driven to operate near their maximum capacity, especially those serving heavy load centers. Wide area controllers (WACs) using wide-area or global signals can provide remote auxiliary control signals to local controllers such as automatic voltage regulators, power system stabilizers, etc to damp out inter-area oscillations. The power system is highly nonlinear system with fast changing dynamics. In order to have an efficient WAC, an online system monitor/predictor is required to provide inter-area information to the WAC from time to time. This paper presents the design of an …

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A New Microsensor System For Plant Root Zone Monitoring, Chang-Soo Kim, Sandeep Sathyan, D. M. Porterfield Jan 2005

A New Microsensor System For Plant Root Zone Monitoring, Chang-Soo Kim, Sandeep Sathyan, D. M. Porterfield

Electrical and Computer Engineering Faculty Research & Creative Works

The objective of this work is to develop a new microsensor system that can monitor dissolved oxygen and hydration environment at the plant root zone. A miniaturized plant growth system is prepared including the root zone layer, either a porous ceramic tube or porous ceramic wafer on which the plant is grown, and an underlying fluidic channel to deliver nutrients and water to the root zone. We demonstrate the feasibility of using a flexible microsensor array for dissolved oxygen detection, and a four-electrode impedance microelectrode for wetness detection on the surface of a porous tube nutrient delivery system. The unique …

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A "Theory Of Action" Perspective On Effective Organizational Change, Ray Luechtefeld Jan 2005

A "Theory Of Action" Perspective On Effective Organizational Change, Ray Luechtefeld

Engineering Management and Systems Engineering Faculty Research & Creative Works

No abstract provided.

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A Generic, Adaptive Systems Engineering Information Model I, Ann K. Miller, Joseph J. Simpson, Scott Erwin Grasman, Cihan H. Dagli Jan 2005

A Generic, Adaptive Systems Engineering Information Model I, Ann K. Miller, Joseph J. Simpson, Scott Erwin Grasman, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper proposes a new network centric architecture that can be used by first responders to effectively respond to crisis situations. The powerful network-centric concept originally developed for and mainly used in the military environment, can be effectively used for civilian security and emergency response missions. This paper also proposes the use of a swarm of intelligent robots as a part of the network-centric architecture to aid the first responders. The swarm of robots works in tandem with the first responders and provides them with the necessary information on a real time basis. The proposed network centric architecture with a …

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Adaptive Critic Designs For Optimal Control Of Power Systems, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

Adaptive Critic Designs For Optimal Control Of Power Systems, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing complexity of the modern power grid highlights the need for advanced modeling and control techniques for effective control of excitation, turbine and flexible AC transmission systems (FACTS). The crucial factors affecting the modern power systems today is voltage and load flow control. Simulation studies in the PSCAD/EMTDC environment and realtime laboratory experimental studies carried out are described and the results show the successful control of the power system elements and the entire power system with adaptive and optimal neurocontrol schemes. Performances of the neurocontrollers are compared with the conventional PI controllers for damping under different operating conditions for …

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Network-Centric First Responder Architecture With Swarming Robots Entity, Lakshmanan Meyyappan, Cihan H. Dagli Jan 2005

Network-Centric First Responder Architecture With Swarming Robots Entity, Lakshmanan Meyyappan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper proposes a new network centric architecture that can be used by first responders to effectively respond to crisis situations. The powerful network-centric concept originally developed for and mainly used in the military environment, can be effectively used for civilian security and emergency response missions. This paper also proposes the use of a swarm of intelligent robots as a part of the network-centric architecture to aid the first responders. The swarm of robots works in tandem with the first responders and provides them with the necessary information on a real time basis. The proposed network centric architecture with a …

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Emi Specifics Of Synchronous Dc-Dc Buck Converters, Zhe Li, David Pommerenke Jan 2005

Emi Specifics Of Synchronous Dc-Dc Buck Converters, Zhe Li, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

DC-DC buck converter topology is widely used in computers and telecom applications because of its high power efficiency and multiple DC levels. However, EMI can be an issue because of its fast switching characteristics and large currents. This paper addresses the analysis of radiated EMI problems associated with DC-DC buck converters and evaluates the effectiveness of solutions that minimize the reverse recovery of the drain-bulk diode of the synchronous switching MOSFET.

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A Microphone Array System For Multimedia Applications With Near-Field Signal Targets, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran, Hongchi Shi Jan 2005

A Microphone Array System For Multimedia Applications With Near-Field Signal Targets, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran, Hongchi Shi

Electrical and Computer Engineering Faculty Research & Creative Works

A microphone array beamforming system is proposed for multimedia communication applications using four sets of small planar arrays mounted on a computer monitor. A new virtual array approach is employed such that the original signals received by the array elements are weighted and delayed to synthesize a large, nonuniformly spaced, harmonically nested virtual array covering the frequency band [50, 7000] Hz of the wideband telephony. Subband multirate processing and near-field beamforming techniques are then used jointly by the nested virtual array to improve the performances in reverberant environments. A new beamforming algorithm is also proposed using a broadband near-field spherically …

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A Novel Method Based On Neural Networks To Distinguish Between Load Harmonics And Source Harmonics In A Power System, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

A Novel Method Based On Neural Networks To Distinguish Between Load Harmonics And Source Harmonics In A Power System, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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