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

Engineering Commons™

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

Electrical and Computer Engineering Faculty Research & Creative Works

Discipline
Keyword
Publication Year

Articles 2521 - 2550 of 3518

Full-Text Articles in Engineering

Reactive Power And Voltage Control Of The Nigerian Grid System Using Micro-Genetic Algorithm, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu Jan 2005

Reactive Power And Voltage Control Of The Nigerian Grid System Using Micro-Genetic Algorithm, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a micro-genetic based approach to the optimization of reactive power and voltage profiles improvement and real power loss minimization is presented. The reactive power control devices such as generators, tap positions of on-load tap changer of transformers, shunt reactors are used to correct voltage limits violations while simultaneously reducing the system real power losses. Genetic algorithms (GAs) are well-known global search techniques anchored on the mechanisms of natural selection and genetics. Because of the time intensive nature of the conventional GA, the micro-GA is proposed as a more time efficient alternative. The feasibility and effectiveness of the …

Go to article

Fast Algorithms For Layered Media, Weng Cho Chew, Bin Hu, Y. C. Pan, Lijun Jiang Jan 2005

Fast Algorithms For Layered Media, Weng Cho Chew, Bin Hu, Y. C. Pan, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper gives an overview of computational electromagnetics for simulating complex structures with a large number of unknowns using integral equation method. First, it discusses the pros and cons of differential equation solvers versus integral equation solvers. Then it gives an overview of different fast algorithms for solving integral equations. It also discusses the difficulty of solving electromagnetic problems in the "twilight zone" between static and full-wave electromagnetics. Finally, it discusses various methods for fast solutions of scattering and coupling problems involving layered media both for statics and dynamic problems, and presents some numerical results. © 2005 Académie des sciences. …

Go to article

Disordered Speech Evaluation Using Objective Quality Measures, Lingyun Gu, John G. Harris, Rahul Shrivastav, Christine Sapienza Jan 2005

Disordered Speech Evaluation Using Objective Quality Measures, Lingyun Gu, John G. Harris, Rahul Shrivastav, Christine Sapienza

Electrical and Computer Engineering Faculty Research & Creative Works

Speech quality assessment methods are necessary for evaluating and documenting treatment outcomes of patients suffering from degraded speech due to Parkinson's disease, stroke or other disease processes. Subjective methods of speech quality assessment are more accurate and more robust than objective methods but are time-consuming and costly. We propose a novel objective measure of speech quality assessment that builds on traditional speech processing techniques such as dynamic time warping (DTW) and the Itakura-Saito (IS) distortion measure. Initial results show that our objective measure correlates well with the more expensive subjective methods. © 2005 IEEE.

Go to article

A Multi-Hypothesis Approach For Salient Object Tracking In Visual Surveillance, Filiz Bunyak, Ilker Ersoy, S. R. Subramanya Jan 2005

A Multi-Hypothesis Approach For Salient Object Tracking In Visual Surveillance, Filiz Bunyak, Ilker Ersoy, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multiple object tracking method for visual surveillance applications is presented. Moving objects are detected by adaptive background subtraction and tracked by using a multi-hypothesis testing approach. Object matching between frames is done based on proximity and appearance similarity. a new confidence measure is assigned to each possible match. This information is arranged into a graph structure where vertices represent blobs in consecutive frames and edges represent match confidence values. This graph is later used to prune and refine trajectories to obtain the salient object trajectories. Occlusions are handled through position prediction using Kalman filter and robust …

Go to article

Block Phase Correlation-Based Automatic Drift Compensation For Atomic Force Microscopes, Qinmin Yang, Eric W. Bohannan, Jagannathan Sarangapani Jan 2005

Block Phase Correlation-Based Automatic Drift Compensation For Atomic Force Microscopes, Qinmin Yang, Eric W. Bohannan, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Automatic nanomanipulation and nanofabrication with an Atomic Force Microscope (AFM) is a precursor for nanomanufacturing. In ambient conditions without stringent environmental controls, nanomanipulation tasks require extensive human intervention to compensate for the many spatial uncertainties of the AFM. Among these uncertainties, thermal drift is especially hard to solve because it tends to increase with time and cannot be compensated simultaneously by feedback. In this paper, an automatic compensation scheme is introduced to measure and estimate drift. This information can be subsequently utilized to compensate for the thermal drift so that a real-time controller for nanomanipulation can be designed as if …

Go to article

Comparison Of Non-Uniform Optimal Quantizer Designs For Speech Coding With Adaptive Critics And Particle Swarm, Wenwei Zha, Ganesh K. Venayagamoorthy Jan 2005

Comparison Of Non-Uniform Optimal Quantizer Designs For Speech Coding With Adaptive Critics And Particle Swarm, Wenwei Zha, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a companding non-uniform optimal scalar quantizer for speech coding. The quantizer is designed using two neural networks to perform the nonlinear transformation. These neural networks are used in the front and back ends of a uniform quantizer. Two approaches are presented in this paper namely adaptive critic designs (ACD) and particle swarm optimization (PSO), aiming to maximize the signal to noise ratio (SNR). The comparison of these optimal quantizer designs over bit rate range of 3 to 6 is presented. The perceptual quality of the coding is evaluated by the International Telecommunication Union''s Perceptual …

Go to article

Data Mining For Distribution System Fault Classification, Badrul H. Chowdhury, H. Manjari Dola Jan 2005

Data Mining For Distribution System Fault Classification, Badrul H. Chowdhury, H. Manjari Dola

Electrical and Computer Engineering Faculty Research & Creative Works

Digital relaying equipment at substations allow for large amounts of data storage that can be triggered by predetermined system conditions. Some of this information retrieved from relays at several locations in a local utility's service territory has been mined for determining trends and relationships. Data mining aims to make sense of the retrieved data by revealing meaningful relationships. This paper discusses some useful data mining techniques that are applied to data recorded by overcurrent relays at several substations. The purpose is to classify faults, verify relay settings and determine fault induced trip per substations. High accuracy is obtained.

Go to article

Double-Tiered Capacitive Shuttling Method For Balancing Series-Connected Batteries, Andrew Baughman, Mehdi Ferdowsi Jan 2005

Double-Tiered Capacitive Shuttling Method For Balancing Series-Connected Batteries, Andrew Baughman, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

The auto industry is progressing towards hybrid and fully electric vehicles in their future car models. These vehicles need a power plant that is reliable during the lifetime of the car. Battery capacity imbalances stemming from the cell manufacturer, ensuing driving environment, and operational usage affect voltage levels, which must follow adherence to strict limits to ensure the safety of the driver. A variation on an existing method of using a capacitor to shuttle charge from one battery to another to balance series strings of batteries is proposed in this paper. The advancement shown in this paper is to bridge …

Go to article

Electromechanical Power Generation For Interplanetary Space Travel Beyond Low Earth Orbit, Badrul H. Chowdhury, Sushant Barave Jan 2005

Electromechanical Power Generation For Interplanetary Space Travel Beyond Low Earth Orbit, Badrul H. Chowdhury, Sushant Barave

Electrical and Computer Engineering Faculty Research & Creative Works

Preliminary results of investigating high frequency power generation using a permanent magnet synchronous machine is presented. The specific application is crew exploration vehicles for space travel beyond low earth orbit.

Go to article

Emi-Debugging Of Complex Systems Using Different Time, Modulation, Stfft And Frequency Domain Signal Analysis Techniques, Zhe Li, David Pommerenke Jan 2005

Emi-Debugging Of Complex Systems Using Different Time, Modulation, Stfft And Frequency Domain Signal Analysis Techniques, Zhe Li, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

One faces a difficult situation in EMI debugging if multiple sources radiate at the same frequency, especially, if little details on the EUT are provided. In this paper, we apply and compare a set of signal analysis techniques for identifying radiated emission sources. First, theoretical background of Joint Time-Frequency Analysis (JTFA) is given and an algorithm using Short-Term Fast Fourier Transform (STFFT) approach is applied for the data analysis. STFFT analysis provides an exclusive insight into time-dependent emission processes. Also, narrow span and zero span spectrum analysis are discussed. Special emphasis is given on signals sideband characteristics.

Go to article

Suitability Of Pulse Train Control Technique For Bifred Converter, Mehdi Ferdowsi, Ali Emadi, Mark Telefus, Anatoly Shteynberg Jan 2005

Suitability Of Pulse Train Control Technique For Bifred Converter, Mehdi Ferdowsi, Ali Emadi, Mark Telefus, Anatoly Shteynberg

Electrical and Computer Engineering Faculty Research & Creative Works

Pulse TrainTM control scheme is presented and applied to a boost integrated flyback rectifier/energy storage dc-dc (BIFRED) converter operating in discontinuous conduction mode (DCM), which avoids the light-load high-voltage stress problem. In contrast to the conventional control techniques, the principal idea of Pulse Train technique is to regulate the output voltage using a series of high and low energy pulses generated by the current of the inductor. The applicability of the proposed technique to both the input and magnetizing inductances of BIFRED converter is investigated. Analysis of BIFRED converter operating in DCM as well as the output voltage ripple …

Go to article

Making The Graduate-Industry Connection, Mariesa Crow Jan 2005

Making The Graduate-Industry Connection, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Many utilities are beginning to ramp up their recruiting and hiring efforts to attract bright young engineering graduates into the industry to replace the large numbers of engineers that have recently retired or will retire in the next few years. Unfortunately, the long drought in hiring brought on by the uncertainty of deregulation and the perspective that the industry is "old and conservative" has caused a mismatch in the interests of young engineers and the companies that want to hire them. in addition, the number of young people pursuing engineering degrees is decreasing as they become attracted to other lucrative …

Go to article

Matched Filter Bound Of Wireless Systems Over Frequency Selective Channels With Receiver Timing Phase Offset, Jingxian Wu, Y. Rosa Zheng, Khaled Ben Letaief, Chengshan Xiao Jan 2005

Matched Filter Bound Of Wireless Systems Over Frequency Selective Channels With Receiver Timing Phase Offset, Jingxian Wu, Y. Rosa Zheng, Khaled Ben Letaief, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

The sampler timing (phase) sensitivity of wireless communication systems is discussed in this paper. Based on the matched filter bound technique, a tight error performance bound is derived for systems experiencing frequency selective Rayleigh fading, with the receiver timing offset being quantified in the error performance expressions. With the error performance bound, the timing phase sensitivity of systems with both symbol spaced receivers and fractionally spaced receivers is analyzed. Simulation results show that the new bound can accurately predict the performance of practical communication systems suffering both frequency selective fading and timing phase offset.

Go to article

Analytical Model For The Rectangular Power-Ground Structure Including Radiation Loss, Ji Chen, Todd H. Hubing, Weimin Shi, R. L. Chen Jan 2005

Analytical Model For The Rectangular Power-Ground Structure Including Radiation Loss, Ji Chen, Todd H. Hubing, Weimin Shi, R. L. Chen

Electrical and Computer Engineering Faculty Research & Creative Works

An accurate analytical model to predict via coupling within rectangular power-return plane structures is developed. Loss mechanisms, including radiation loss, dielectric loss, and conductor loss, are considered in this model. The radiation loss is incorporated into a complex propagating wavenumber as an artificial loss mechanism. The quality factors associated with three loss mechanisms are calculated and compared. The effects of radiation loss on input impedances and reflection coefficients are investigated for both high-dielectric-loss and low-dielectric-loss printed circuit boards. Measurements are performed to validate the effectiveness of this model.

Go to article

An Adaptive Mamdani Fuzzy Logic Based Controller For A Static Compensator In A Multimachine Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

An Adaptive Mamdani Fuzzy Logic Based Controller For A Static Compensator In A Multimachine Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive Mamdani based fuzzy logic controller has been designed for controlling a static compensator (STATCOM) in a multimachine power system. Such a controller does not need any prior knowledge of the plant to be controlled and can efficiently control a STATCOM during different disturbances in the network. A model free approach using the controller output error is applied for training purposes that adaptively changes the controller output parameters based on a gradient descent method. Moreover, shrinking span membership functions are used for a more stable and accurate control performance. Simulation results show that the proposed controller outperforms the conventional …

Go to article

Two Separate Continually Online-Trained Neurocontrollers For A Unified Power Flow Controller, Ganesh K. Venayagamoorthy, Radha P. Kalyani Jan 2005

Two Separate Continually Online-Trained Neurocontrollers For A Unified Power Flow Controller, Ganesh K. Venayagamoorthy, Radha P. Kalyani

Electrical and Computer Engineering Faculty Research & Creative Works

The crucial factor affecting the modern power systems today is load flow control. The Unified Power Flow Controller (UPFC) provides an effective means for controlling the power flow and improving the transient stability in a power network. The UPFC has fast complex dynamics and its conventional control is based on a linearized model of the power system. This paper presents the design of neurocontrollers to provide better damping during transient and dynamic control. Two separate neurocontrollers are used for controlling the UPFC, one neurocontroller for the shunt inverter and the other for the series inverter. Simulation studies carried out in …

Go to article

Influence Of Oxygen Microenvironment On Microfluidic Glucose Sensor Performance, Chang-Soo Kim, Jongwon Park Jan 2005

Influence Of Oxygen Microenvironment On Microfluidic Glucose Sensor Performance, Chang-Soo Kim, Jongwon Park

Electrical and Computer Engineering Faculty Research & Creative Works

We propose a novel method to overcome significant problems of baseline drift and sensitivity degradation in amperometric biosensors based on oxidase enzyme reactions. A novel glucose microsensor with a built-in electrochemical oxygen manipulation microsystem is introduced to demonstrate three novel functionalities; one-point in situ self-calibration (zero-point), broadening of dynamic range and increase in sensitivity. The influence of electrochemically generated oxygen microenvironment on the sensor output within a fluidic structure is investigated.

Go to article

A Comparison Of Pso And Backpropagation For Training Rbf Neural Networks For Identification Of A Power System With Statcom, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Yamille Del Valle, Ronald G. Harley Jan 2005

A Comparison Of Pso And Backpropagation For Training Rbf Neural Networks For Identification Of A Power System With Statcom, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Yamille Del Valle, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Backpropagation algorithm is the most commonly used algorithm for training artificial neural networks. While being a straightforward procedure, it suffers from extensive computations, relatively slow convergence speed and possible divergence for certain conditions. The efficiency of this method as the training algorithm of a radial basis function neural network (RBFN) is compared with that of particle swarm optimization, for neural network based identification of a small power system with a static compensator. The comparison of the two methods is based on the convergence speed and robustness of each method.

Go to article

A New Test Setup And Method For The Calibration Of Current Clamps, David Pommerenke, Ramachandran Chundru, Sunitha Chandra Jan 2005

A New Test Setup And Method For The Calibration Of Current Clamps, David Pommerenke, Ramachandran Chundru, Sunitha Chandra

Electrical and Computer Engineering Faculty Research & Creative Works

Current probes are widely used to measure the common mode currents in electromagnetic compatibility (EMC) applications. Often, it is necessary to characterize the ratio of measured voltage to the common mode currents up to gigahertz (GHz) frequencies. Existing calibration methods for current probes suffer from the problem of not directly measuring the current within the current clamp. Instead they either reconstruct the current from measurements at other locations or they use assumptions regarding the geometry which allows them to use a current that is measured at a different location without applying a mathematical correction. For example, by maintaining a 50-Ω …

Go to article

A Robust Controller For The Manipulation Of Micro Scale Objects, Qinmin Yang, Jagannathan Sarangapani Jan 2005

A Robust Controller For The Manipulation Of Micro Scale Objects, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A suite of novel robust controllers is presented for the manipulation and handling of micro-scale objects in a micro-electromechanical system (MEMS) where adhesive, surface tension, friction and van der Waals forces are dominant. Moreover, these forces are typically unknown. The robust controller overcomes the unknown system dynamics and ensures the performance in the presence of actuator constraints by assuming that the upper bounds on these forces are known. On the other hand, for the robust adaptive controller, the unknown forces are estimated online. Using the Lyapunov approach, the uniformly ultimate boundedness (UUB) of the closed-loop manipulation error is shown for …

Go to article

Aircraft Cabin Noise Minimization Via Neural Network Inverse Model, Xiao Hu, G. Clark, M. Travis, J. L. Vian, Donald C. Wunsch Jan 2005

Aircraft Cabin Noise Minimization Via Neural Network Inverse Model, Xiao Hu, G. Clark, M. Travis, J. L. Vian, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes research to investigate an artificial neural network (ANN) approach to minimize aircraft cabin noise in flight. The ANN approach is shown to be able to accurately model the non-linear relationships between engine unbalance, airframe vibration, and cabin noise to overcome limitations associated with traditional linear influence coefficient methods. ANN system inverse models are developed using engine test-stand vibration data and on-airplane vibration and noise data supplemented with influence coefficient empirical data. The inverse models are able to determine balance solutions that satisfy cabin noise specifications. The accuracy of the ANN model with respect to the real system …

Go to article

An Embedded Real-Time Neuro-Fuzzy Controller For Mobile Robot Navigation, Nian Zhang, Daryl G. Beetner, Donald C. Wunsch, B. Hemmelman, Ahmad Hasan Jan 2005

An Embedded Real-Time Neuro-Fuzzy Controller For Mobile Robot Navigation, Nian Zhang, Daryl G. Beetner, Donald C. Wunsch, B. Hemmelman, Ahmad Hasan

Electrical and Computer Engineering Faculty Research & Creative Works

A reactive fuzzy logic based control strategy was developed for mobile robot navigation. To decrease the number of fuzzy rules and related processing, a RAM-based neural network was combined with the fuzzy logic strategy. The fuzzy rules are used to interpret sensor information. The neural network uses results from the fuzzy logic as well as environmental information to make navigation decisions. The feasibility of this neuro-fuzzy approach was demonstrated on a mobile robot using a simple, 8-bit microcontroller. Experiments show the approach works well, as the robot was able to successfully avoid objects while seeking a goal in real-time. The …

Go to article

Analysis Of A Low-Pass Filter Employing A 4-Pin Capacitor, A. Ritter, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff Jan 2005

Analysis Of A Low-Pass Filter Employing A 4-Pin Capacitor, A. Ritter, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff

Electrical and Computer Engineering Faculty Research & Creative Works

Capacitors with two or three leads tend to make poor low-pass filters at high frequencies (e.g. greater than 100 MHz) due to the mutual inductance between the input and output sides of the filter. This work proposes a four-lead low-pass filter capacitor design that minimizes the magnetic flux coupling between the input and output. Measurements of a prototype capacitor confirm that it performs significantly better than a typical two-lead capacitor at high frequencies.

Go to article

Decentralized Discrete-Time Neural Network Controller For A Class Of Nonlinear Systems With Unknown Interconnections, Jagannathan Sarangapani Jan 2005

Decentralized Discrete-Time Neural Network Controller For A Class Of Nonlinear Systems With Unknown Interconnections, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized neural network (NN) controller in discrete-time is designed for a class of uncertain nonlinear discrete-time systems with unknown interconnections. Neural networks are used to approximate both the uncertain dynamics of the nonlinear systems and the unknown interconnections. Only local signals are needed for the decentralized controller design and the stability of the overall system can be guaranteed using the Lyapunov analysis. Further, controller redesign for the original subsystems is not required when additional subsystems are appended. Simulation results demonstrate the effectiveness of the proposed controller. The NN does not require an offline learning phase and the weights …

Go to article

The Method Of Auxiliary Sources As An Efficient Numerical Technique For Large 3d Semi Open Structures, R. S. Zaridze, D. G. Kakulia, K. N. Tavzarashvili, David Pommerenke, G. N. Ghvedashvili, Kai Xiao Jan 2005

The Method Of Auxiliary Sources As An Efficient Numerical Technique For Large 3d Semi Open Structures, R. S. Zaridze, D. G. Kakulia, K. N. Tavzarashvili, David Pommerenke, G. N. Ghvedashvili, Kai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

The method of auxiliary sources (MAS) has been demonstrated as suitable for solution of diffraction and inverse problems in complex 2D large objects. Based on MAS numerical study of 3D RCS, EMC/EMI and SAR problems, related to the EM field resonance enhancement inside vehicles and the interaction of the cellular telephone radiation with the user''s head are given in other work. The objective of this paper is to present details of MAS application to the wide 3D electrodynamic problems. The area of its efficient application, some features and advantages to achieving efficient solutions, are discussed. The extension of the MAS …

Go to article

Traces In Proximity To Gaps In Return Planes, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff Jan 2005

Traces In Proximity To Gaps In Return Planes, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff

Electrical and Computer Engineering Faculty Research & Creative Works

Coupling between circuitry on printed circuit boards can be mitigated by a variety of well-known techniques. One such technique is to isolate circuitry in different areas of the printed circuit board by strategically placing a gap in the signal return plane. However, this technique is only effective at reducing common-impedance coupling, which is generally not a significant coupling mechanism at frequencies above 1 MHz. This paper investigates the effect of a gap located between and parallel to adjacent microstrip traces. The effect of the gap on the mutual inductance and mutual capacitance is evaluated. Laboratory measurements and numerical simulations show …

Go to article

Trends In Process Control Systems Security, Ann K. Miller Jan 2005

Trends In Process Control Systems Security, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

The protection of critical infrastructure systems is a hotly debated topic. The very label "critical infrastructure" implies that these systems are important, and they are: they support our everyday lives, from the water and food in our homes to our physical and financial welfare. This article explores the recent evolution of programmable logic controllers (PCSs) and their environments, explains the need for improved security in these systems, and describes some of the emerging research areas that offer promise in PCS security.

Go to article

A Heuristic-Dynamic-Programming-Based Power System Stabilizer For A Turbogenerator In A Single-Machine Power System, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch Jan 2005

A Heuristic-Dynamic-Programming-Based Power System Stabilizer For A Turbogenerator In A Single-Machine Power System, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Power system stabilizers (PSSs) are used to generate supplementary control signals for the excitation system in order to damp the low-frequency power system oscillations. To overcome the drawbacks of a conventional PSS (CPSS), numerous techniques have been proposed in the literature. Based on the analysis of existing techniques, a novel design based on heuristic dynamic programming (HDP) is presented in this paper. HDP, combining the concepts of dynamic programming and reinforcement learning, is used in the design of a nonlinear optimal power system stabilizer. Results show the effectiveness of this new technique. The performance of the HDP-based PSS is compared …

Go to article

A Novel Method For Predicting Harmonic Current Injection From Non-Linear Loads Using Neural Networks, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2005

A Novel Method For Predicting Harmonic Current Injection From Non-Linear Loads Using Neural Networks, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Generation of harmonics and the existence of waveform pollution in power system networks is one of the major problems facing the utilities. This paper proposes a neural network solution methodology for the problem of measuring the actual amount of harmonic current injected into a power network by a nonlinear load. The determination of harmonic currents is complicated by the fact that the supply voltage waveform is distorted by other loads and is rarely a pure sinusoid. A recurrent neural network trained with the backpropagation through time (BPTT) training algorithm is used to find a way of distinguishing between the load …

Go to article

Energy-Efficient Rate Adaptation Mac Protocol For Ad Hoc Wireless Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani Jan 2005

Energy-Efficient Rate Adaptation Mac Protocol For Ad Hoc Wireless Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Resource constraints in ad hoc wireless networks require that they are energy efficient during both transmission and rate adaptation. In this paper, we propose a novel energy-efficient rate adaptation protocol that selects modulation schemes online to maximize throughput based on channel state while saving energy. This protocol uses the distributed power control (DPC) algorithm (M. Zawodniok et al., 2004) to accurately determine the necessary transmission power and to reduce the energy consumption. Additionally, the transmission rate is altered using energy efficiency as a constraint to meet the required throughput, which is estimated with queue fill ratio. Moreover, back-off scheme is …

Go to article

First Prev Next Last