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Electrical and Computer Engineering Faculty Research & Creative Works

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Full-Text Articles in Engineering

Test Bed Evaluation Of Future Power Distribution Systems With Renewable Resources, Bharadwaj R. Sathyanarayana, Gerald T. Heydt, Mariesa Crow, Fanjun Meng Dec 2009

Test Bed Evaluation Of Future Power Distribution Systems With Renewable Resources, Bharadwaj R. Sathyanarayana, Gerald T. Heydt, Mariesa Crow, Fanjun Meng

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, the National Science Foundation (NSF) has inaugurated an Engineering Research Center dedicated to Future Renewable Electric Energy Distribution Management (FREEDM). the premise of the center is to enable the utilization of renewable resources in power distribution systems through the utilization of solid-state controllers and direct digital control. the center is at an initial stage and the focus of some effort is on the development of a test bed that will allow the evaluation of alternative system configurations, controls, solid state controllers, and operations strategies. This paper describes some of those considerations and the requirements for a test bed for …

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Emc Guideline For Synchronous Buck Converter Design, Keong Kam, David Pommerenke, Federico Centola, Cheung Wei Lam, Robert Steinfeld Dec 2009

Emc Guideline For Synchronous Buck Converter Design, Keong Kam, David Pommerenke, Federico Centola, Cheung Wei Lam, Robert Steinfeld

Electrical and Computer Engineering Faculty Research & Creative Works

Synchronous buck converters generate broadband noise typically in 50 - 300 MHz range. in this paper, the root cause of this broadband noise and possible coupling mechanisms are analyzed. Then, a list of EMC design guideline for minimizing the broadband noise is presented. the guideline contains circuit level guideline which involves input filtering, component selection, and an effective snubber strategy using a parallel resistor and inductor. the guideline also contains layout level guideline, which involves decoupling capacitor placement, layer stack up, and minimizing exposed phase voltage area. for each suggested guideline item, an example illustrates the impact of the particular …

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Analytical Formulas For The Barrel-Plate And Pad-Plate Capacitance In The Physics-Based Via Circuit Model For Signal Integrity Analysis Of Pcbs, Yaojiang Zhang, Erping Li, Zawzaw Oo, Wenzu Zhang, Enxiao Liu, Xinchang Wei, Jun Fan Dec 2009

Analytical Formulas For The Barrel-Plate And Pad-Plate Capacitance In The Physics-Based Via Circuit Model For Signal Integrity Analysis Of Pcbs, Yaojiang Zhang, Erping Li, Zawzaw Oo, Wenzu Zhang, Enxiao Liu, Xinchang Wei, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

The current distribution along via barrel and pad is obtained by the Green's function of a generalized coaxial cavity for a magnetic frill current. an analytical formula for both the barrel-plate and pad-plate capacitances are derived by observing the current difference along the via barrel and pad. Finite difference method has been used to validate the formula derived here. Analytical formula presented facilitates the implementation of the physics-Based via circuit model in practical via designs for printed circuit boards and packages. the impact of various via geometric parameters on the parasitic capacitances has been investigated. ©2009 IEEE.

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On The Dual Basis For Solving Electromagnetic Surface Integral Equations, Mei Song Tong, Weng Cho Chew, Barry J. Rubin, Jason D. Morsey, Lijun Jiang Dec 2009

On The Dual Basis For Solving Electromagnetic Surface Integral Equations, Mei Song Tong, Weng Cho Chew, Barry J. Rubin, Jason D. Morsey, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A powerful technique for solving electromagnetic (EM) surface integral equations (SIEs) for inhomogenous objects by the method of moments (MoM) involves the well-known RaoWiltonGlisson (RWG) basis function to represent the electric current and, for field orthogonality and numerical stability reasons, a variation of the RWG basis known as the ňx RWG basis (where ň is a unit normal vector at the object surface) to represent the magnetic current. Though this combination provides a numerically efficient and effective solution that has been demonstrated on a variety of structures, one cannot feel entirely comfortable because of the presence of fictitious magnetic current …

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Electrical-Thermal Co-Analysis For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin Dec 2009

Electrical-Thermal Co-Analysis For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an electrical-thermal co-analysis method for power delivery networks in 3D system integration is proposed. For electrical analysis, temperature-dependent electrical resistivity of conductors is taken into account. For thermal analysis, Joule heating effect due to the current flowing through conductors is considered. The proposed co-analysis method is carried out using Rgen and ChipJoule of IBM EIP Tool Suite. An example of 3D integration system including stacked chips, power delivery network, glass-ceramic substrate, through-silicon vias, controlled collapse chip connections (C4s), underfill material, and TIM is analyzed using the proposed method. The simulation results show that the temperature effect on …

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Unit Commitment With Vehicle-To-Grid Using Particle Swarm Optimization, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy Dec 2009

Unit Commitment With Vehicle-To-Grid Using Particle Swarm Optimization, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Vehicle-to-Grid (V2G) technology has drawn great interest in the recent years. Success of the V2G research depends on efficient scheduling of grid able vehicles in limited parking lots. V2G can reduce dependencies on small expensive units in the existing power systems as energy storage that can decrease running costs. It can efficiently manage load fluctuation, peak load; however, it increases spinning reserves and reliability. as number of grid able vehicles in V2G is much higher than small units of existing systems, unit commitment (UC) with V2G is more complex than basic UC for thermal units. Particle swarm optimization (PSO) is …

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Layered Frequency-Domain Equalization For Single Carrier Mimo Systems With Multiple Carrier Frequency Offsets, Jian Zhang, Yahong Rosa Zheng Dec 2009

Layered Frequency-Domain Equalization For Single Carrier Mimo Systems With Multiple Carrier Frequency Offsets, Jian Zhang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, carrier frequency offsets (CFOs) are considered in a layered frequency-domain equalization (LFDE) architecture for a single carrier (SC) broadband wireless multiple-input multiple-output (MIMO) system. at each layer of detection, a group of best data streams are selected to be equalized and reliably detected via removing the phase and amplitude distortion caused by the multiple CFOs. the estimated phase rotations and amplitude scalars are required to be compensated to the detected data streams in order to reconstruct the interference signals which are canceled out from the received signals. Instead of direct estimation of CFOs, our algorithm is to …

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Further Development Of The Overload Risk Index, An Indicator Of System Vulnerability, John Rossmaier, Badrul Chowdhury Dec 2009

Further Development Of The Overload Risk Index, An Indicator Of System Vulnerability, John Rossmaier, Badrul Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

This paper develops and expands on a previously devised vulnerability index in an attempt to make the index more robust in describing a power system's total vulnerability level. the previous index was derived using a dc load flow analysis using line outage distribution factors and Monte Carlo simulation that incorporated the unavailability rates of the transmission lines within the system. the updated index incorporates the following improvements: (a) tests to determine bus islanding in the system, (b) steady-state stability tests, (c) an optimal power flow to determine a more accurate steady-state point of operation, (d) ac analysis for a greater …

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A Frequency Domain Doubletalk Detector Based On Cross-Correlation And Extension To Multi-Channel Case, Mohammad Asif Iqbal, Steven L. Grant, Jack W. Stokes Dec 2009

A Frequency Domain Doubletalk Detector Based On Cross-Correlation And Extension To Multi-Channel Case, Mohammad Asif Iqbal, Steven L. Grant, Jack W. Stokes

Electrical and Computer Engineering Faculty Research & Creative Works

Most teleconferencing conversations are conducted in the presence of Acoustic echoes. Typically, an adaptive filter is used to cancel the echo, with a control device called the doubletalk detector which controls the adaptation. We derive a novel test statistic for the doubletalk detection based on the cross-correlation between the microphone signal and the cancellation error for the frequency domain adaptive algorithm. the main advantage of the proposed algorithm is its simplicity and computational efficiency. We compare our results with the normalized cross-correlation based doubletalk detector proposed in [2]. We also generalize the idea of the proposed doubletalk detector (single channel) …

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Predicting Noise Voltage From Trace Crossing Split Planes On Printed Circuit Boards, Weifeng Pan, Samuel Connor, Bruce Archambeault Dec 2009

Predicting Noise Voltage From Trace Crossing Split Planes On Printed Circuit Boards, Weifeng Pan, Samuel Connor, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

Printed circuit Boards (PCBs) often have high speed data traces crossing splits in the adjacent reference planes due to space limitations and cost constraints. These split planes are usually different power islands on nearby layers. This work quantifies the effect of the split plane and the associated stitching capacitor for various stack up configurations. © 2009 IEEE.

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Closed-Form Expression Of Self/Mutual Power-Bus Impedances In A Finite Circular Plate Pair, Yao Jiang Zhang, Er Ping Li, Jun Fan Dec 2009

Closed-Form Expression Of Self/Mutual Power-Bus Impedances In A Finite Circular Plate Pair, Yao Jiang Zhang, Er Ping Li, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

The drawbacks of conventional power-bus impedance, defined as an average Green's function integration over port areas, are discussed. a new definition is proposed in terms of cylindrical waves. the equivalence of the new definition and the conventional one is proved in the case of electrically small ports. Addition theorems of cylindrical waves are used to derive an analytical expression of power-bus impedance between ports in a circular plate pair with perfectly electric/magnetic conductor (PEC/PMC) boundaries as well as non-reflective perfectly matched layer (PML) for infinite plate pair. Numerical method has been used to validate the analytical expression derived.

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Ultracapacitor Frequency Analysis And Its Equivalent Circuit Modeling, Xiaomeng Li, Mariesa Crow Dec 2009

Ultracapacitor Frequency Analysis And Its Equivalent Circuit Modeling, Xiaomeng Li, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Energy storage system is becoming more and more important in power electronics device. the Ultracapacitor or so-called electrochemical capacitor is one of the most popular choices for the energy storage system because of its distinct characters. in the application UCAP's transient behavior need to be studied for design purpose. Usually, these transient characters are not shown in the product data sheet. in this paper UCAP frequency analysis is performed, and based on the test data the equivalent model of the UCAP is built. the fitting result shows that using multi-level ladder circuit can perfectly fit the UCAP transient characters.

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Investigation Of Crosstalk Among Vias, Songping Wu, Jun Fan Dec 2009

Investigation Of Crosstalk Among Vias, Songping Wu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Crosstalk among vias is a critical problem in highspeed digital circuits, deteriorating signal quality and increasing jitter, especially when circuit density is high. Underlying mechanism of crosstalk among vias is investigated in this paper. using a physics-Based equivalent circuit model, crosstalk as a function of various geometrical parameters, including parallel plane pair thickness, layer count in printed circuit board (PCB) stack up, ground via patterns, and parallel plane pair dimensions, has been investigated. a multi-step crosstalk evaluation procedure is proposed based on the study for PCB layout-design verifications. © 2009 IEEE.

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Equivalent Mixed-Mode Characteristic Impedances For Differential Signal Vias, Siming Pan, Jun Fan Dec 2009

Equivalent Mixed-Mode Characteristic Impedances For Differential Signal Vias, Siming Pan, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Differential signal via structures in multi-layer printed circuit boards (PCBs) and packages are studied using an equivalent coupled multi-conductor transmission-line model. Thus, easy-to-understand transmission-line concepts, such as mixed-mode characteristic impedances and propagation constants, can be used to characterize the performance of differential signal via structures in a signal path. the closed-form expressions of per-unit-length parameters in the equivalent coupled multi-conductor transmission-line model are derived based on a physics-Based via circuit model with parallel-plane impedances and via-plate capacitances. Mode conversions are discussed for different via structures. Effects of geometrical parameters on equivalent differential via impedances are studied in the paper as …

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A Real-Time Implementation Of A Pbil Based Stabilizing Controller For Synchronous Generator, Komla A. Folly, Ganesh K. Venayagamoorthy Dec 2009

A Real-Time Implementation Of A Pbil Based Stabilizing Controller For Synchronous Generator, Komla A. Folly, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the optimal tuning of power system stabilizer parameters using a newly introduced evolutionary algorithm called Population based Incremental Learning (PBIL). to robustly stabilize the system, an objective function that minimizes the infinity norm of the closed-loop system is introduced such that the parameters of a fixed structure PSS are optimally tuned, and the controller stabilizes a pre-specified set of system models. the PBIL-PSS is compared with the Conventional PSS (CPSS). the simulation results presented in this paper show that the proposed PBIL-PSS is more effective than the Conventional PSS in damping the low frequency oscillations. the performance …

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Comparison Among Different Via Models Based On Feature Selective Validation Technique, Siming Pan, Hanfeng Wang, Jun Fan Dec 2009

Comparison Among Different Via Models Based On Feature Selective Validation Technique, Siming Pan, Hanfeng Wang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

A new approach is proposed in this paper to validate different uncertain approaches without knowing a standard reference by applying the Feature Selective Validation (FSV) technique. New reference is established by the weighted average of the various approaches. Four via modeling methods including physics-Based circuit model, equivalent transmission line model, multiple scattering model, and full wave model are compared and validated by the approach proposed in this paper to illustrate the effectiveness of different via modeling techniques. © 2009 IEEE.

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Bio-Inspired Node Localization In Wireless Sensor Networks, Raghavendra V. Kulkarni, Ganesh K. Venayagamoorthy, Maggie X. Cheng Dec 2009

Bio-Inspired Node Localization In Wireless Sensor Networks, Raghavendra V. Kulkarni, Ganesh K. Venayagamoorthy, Maggie X. Cheng

Electrical and Computer Engineering Faculty Research & Creative Works

Many applications of wireless sensor networks (WSNs) require location information of the randomly deployed nodes. a common solution to the localization problem is to deploy a few special beacon nodes having location awareness, which help the ordinary nodes to localize. in this approach, non-beacon nodes estimate their locations using noisy distance measurements from three or more non-collinear beacons they can receive signals from. in this paper, the ranging-Based localization task is formulated as a multidimensional optimization problem, and addressed using bio-inspired algorithms, exploiting their quick convergence to quality solutions. an investigation on distributed iterative localization is presented in this paper. …

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Model-To-Hardware Correlation Of Disk Resonators For Via-Array Modeling In High-Speed Pcbs, Arun Reddy Chada, Young H. Kwark, Xiaoxiong Gu, Jun Fan Dec 2009

Model-To-Hardware Correlation Of Disk Resonators For Via-Array Modeling In High-Speed Pcbs, Arun Reddy Chada, Young H. Kwark, Xiaoxiong Gu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In high-speed printed circuit board (PCB) designs, vias play a critical role in determining signal and power integrity. This paper uses disk resonators to investigate modeling approaches for common via array structures. Boundary integral equation (BIE) and effective dielectric medium approaches are used for a perforated disk resonator with non-plated holes, using dielectric properties derived from a solid disk resonator study. Both approaches are compared and validated with measurements. ©2009 IEEE.

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Effect Of System Components On Electrical And Thermal Characteristics For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin Dec 2009

Effect Of System Components On Electrical And Thermal Characteristics For Power Delivery Networks In 3d System Integration, Jianyong Xie, Daehyun Chung, Madhavan Swaminathan, Michael Mcallister, Alina Deutsch, Lijun Jiang, Barry J. Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, parameterized electrical-thermal co-analysis for power delivery networks (PDN) in 3D system integration is carried out. A 3D integrated system including glass-ceramic substrate, single and stacked dies, power delivery network, through-silicon vias (TSVs), controlled collapse chip connections (C4s), underfill material, and thermal interface material (TIM) is analyzed with several variable parameters. The analysis results show that temperature effects on DC IR drop can not be neglected. The TIM thermal conductivity, C4 density, stacking order of stacked dies, and voltage source location affect the final IR drop and hot spot temperature in the system. ©2009 IEEE.

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Neural Network Control Of A Class Of Nonlinear Discrete Time Systems With Asymptotic Stability Guarantees, Balaje T. Thumati, Sarangapani Jagannathan Nov 2009

Neural Network Control Of A Class Of Nonlinear Discrete Time Systems With Asymptotic Stability Guarantees, Balaje T. Thumati, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a single and multi-layer neural network (NN) controllers are developed for a class of nonlinear discrete time systems. under a mild assumption on the system uncertainties, which include unmodeled dynamics and bounded disturbances, by using novel weight update laws and a robust term, local asymptotic stability of the closed-loop system is guaranteed in contrast with all other NN controllers where a uniform ultimate boundedness is normally shown. Simulation results are presented to show the effectiveness of the controller design. © 2009 AACC.

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R-Factor: A New Parameter To Enhance Location Accuracy In Rssi Based Real-Time Location Systems, Mohammed Rana Basheer, Sarangapani Jagannathan Nov 2009

R-Factor: A New Parameter To Enhance Location Accuracy In Rssi Based Real-Time Location Systems, Mohammed Rana Basheer, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

The fundamental cause of localization error in an indoor environment is fading and spreading of the radio signals due to scattering, diffraction, and reflection. These effects are predominant in regions where there is no-line-of-sight (NLoS) between the transmitter and the receiver. Efficient algorithms are needed to identify the subset of receivers that provide better localization accuracy. © 2009 IEEE.

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Neural Network Control Of Quadrotor Uav Formations, Travis Dierks, Sarangapani Jagannathan Nov 2009

Neural Network Control Of Quadrotor Uav Formations, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel framework for leader-follower formation control is developed for the control of multiple quadrotors unmanned aerial vehicles (UAVs) based on spherical coordinates. the control objective for the follower UAV is to track its leader at a desired- separation, angle of incidence, and a bearing by using an auxiliary velocity control. Then, a novel neural network (NN) control law for the dynamical system is introduced to learn the complete dynamics of the UAV including unmodeled dynamics like aerodynamic friction. Additionally, the interconnection dynamic errors between the leader and its followers are explicitly considered, and the stability of …

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A Model Based Fault Detection And Accommodation Scheme For Nonlinear Discrete-Time Systems With Asymptotic Stability Guarantee, Balaje T. Thumati, Sarangapani Jagannathan Nov 2009

A Model Based Fault Detection And Accommodation Scheme For Nonlinear Discrete-Time Systems With Asymptotic Stability Guarantee, Balaje T. Thumati, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a fault detection and accommodation (FDA) framework is developed for unknown nonlinear discrete-time systems. the changes in the system dynamics due to the faults are modeled as a nonlinear function of state and input variables while the time profile of the fault is assumed to be exponentially developing. a fault is detected by monitoring the system states and reconstructing the fault dynamics using online approximators. the online approximator output is used first for fault detection and later reconfigured for accommodation. a stable adaptation law in discrete time is developed not only to characterize the faults but also …

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An Alpha Derivative Formulation Of The Hamilton-Jacobi-Bellman Equation Of Dynamic Programming, John Seiffertt Nov 2009

An Alpha Derivative Formulation Of The Hamilton-Jacobi-Bellman Equation Of Dynamic Programming, John Seiffertt

Electrical and Computer Engineering Faculty Research & Creative Works

The time scales calculus, which includes the study of the alpha derivative, is an emerging key area in mathematics. We extend this calculus to Approximate Dynamic Programming. in particular, we investigate application of the alpha derivative, one of the fundamental dynamic derivatives of time scales. We present an alpha-derivative based derivation and proof of the Hamilton-Jacobi-Bellman equation, the solution of which is the fundamental problem in the Held of dynamic programming. by drawing together the calculus of time scales and the applied area of stochastic control via Approximate Dynamic Programming, we connect two major fields of research. © 2009 IEEE.

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Adaptive Dynamic Programming-Based Optimal Control Of Unknown Affine Nonlinear Discrete-Time Systems, Travis Dierks, Balaje T. Thumati, S. Jagannathan Nov 2009

Adaptive Dynamic Programming-Based Optimal Control Of Unknown Affine Nonlinear Discrete-Time Systems, Travis Dierks, Balaje T. Thumati, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Discrete time approximate dynamic programming (ADP) techniques have been widely used in the recent literature to determine the optimal or near optimal control policies for nonlinear systems. However, an inherent assumption of ADP requires at least partial knowledge of the system dynamics as well as the value of the controlled plant one step ahead. in this work, a novel approach to ADP is attempted while relaxing the need of the partial knowledge of the nonlinear system. the proposed methodology entails a two-part process: online system identification and offline optimal control training. First, in the identification process, a neural network (NN) …

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Decentralized Control Of Large Scale Interconnected Systems Using Adaptive Neural Network-Based Dynamic Surface Control, Shahab Mehraeen, Sarangapani Jagannathan, Mariesa L. Crow Nov 2009

Decentralized Control Of Large Scale Interconnected Systems Using Adaptive Neural Network-Based Dynamic Surface Control, Shahab Mehraeen, Sarangapani Jagannathan, Mariesa L. Crow

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized controller using the dynamic surface control (DSC) is proposed for a class of uncertain large scale interconnected nonlinear systems in strict feedback form while relaxing the "explosion of complexity" problem which is observed in the typical backstepping approach. the matching condition is not assumed when dealing with the interconnection terms. Neural networks (NNs) are utilized to approximate the uncertainties in both subsystem and interconnected terms. by using novel NN weight update laws, it is demonstrated using Lyapunov stability that the closed-loop signals are asymptotically stable in the presence of NN approximation errors in contrast with the uniform …

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Robust Sybil Detection For Manets, Athichart Tangpong, George Kesidis, Hung Yuan Hsu, Ali Hurson Nov 2009

Robust Sybil Detection For Manets, Athichart Tangpong, George Kesidis, Hung Yuan Hsu, Ali Hurson

Electrical and Computer Engineering Faculty Research & Creative Works

In this research, we propose a robust Sybil attack detection framework for MANETs based on cooperative monitoring of network activities. We do not require designated and honest monitors to perform the Sybil attack detection. Each mobile node in the network observes packets passing through it and periodically exchanges its observations in order to determine the presence of an attack. Malicious nodes fabricating false observations will be detected and rendered ineffective. Our framework requires no centralized authority and, thus, is scalable in expanding network size. Privacy of each mobile node is also a consideration of our framework. Our preliminary experimental results …

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Adaptive Distributed Fair Scheduling For Multiple Channels In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Nov 2009

Adaptive Distributed Fair Scheduling For Multiple Channels In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda

Electrical and Computer Engineering Faculty Research & Creative Works

A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks (WSN) in the presence of multiple channels (MC-ADFS) is developed. The proposed MC-ADFS increases available network capacity and focuses on quality-of-service (QoS) issues. when nodes access a shared channel, the proposed MC-ADFS allocates the channel bandwidth proportionally to the packet's weight which indicates the priority of the packet's flow. The packets are dynamically assigned to channels based on the packet weight and current channel utilization. The dynamic assignment of channels is facilitated by use of receiver-based allocation and alternative routes. Moreover, MC-ADFS allows the dynamic allocation of …

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Particle Swarm Optimization Tuned Flatness-Based Generator Excitation Controller, Ganesh K. Venayagamoorthy, E. C. Anene, U. O. Aliyu Nov 2009

Particle Swarm Optimization Tuned Flatness-Based Generator Excitation Controller, Ganesh K. Venayagamoorthy, E. C. Anene, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

An optimal transient controller for a synchronous generator in a multi-machine power system is designed using the concept of flatness-based feedback linearization in this paper. The computation of the flat output and corresponding controller for reduced order model of the synchronous generator is presented. The required feedback gains used to close the linearization loop is optimized using particle swarm optimization for maximum damping. Typical results obtained for transient disturbances on a two-area, four-generator power system equipped with the proposed controller on one generator and conventional power system stabilizers on the remaining generators are presented. The effectiveness of the flatness-based controller …

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Stimulus Reconstruction From The Biphasic Integrate-And-Fire Sampler, Alexander Singh Alvarado, José C. Príncipe, John G. Harris Oct 2009

Stimulus Reconstruction From The Biphasic Integrate-And-Fire Sampler, Alexander Singh Alvarado, José C. Príncipe, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm to recover the encoded stimulus from a biphasic integrate-and-fire model has been proposed using the sampling framework for local averages. The algorithm converges for sparse sampling sets, common in extracellular neural recordings. Moreover, the spike region can be recovered with up to 50 dB accuracy even though the instantaneous and overall pulse rates are below the Nyquist bound. ©2009 IEEE.

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