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Electrical and Computer Engineering Faculty Research & Creative Works

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Articles 2401 - 2430 of 3518

Full-Text Articles in Engineering

Development And Implementation Of Optimized Energy-Delay Sub-Network Routing Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Jan 2006

Development And Implementation Of Optimized Energy-Delay Sub-Network Routing Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda

Electrical and Computer Engineering Faculty Research & Creative Works

The development and implementation of the optimized energy-delay sub-network routing (OEDSR) protocol for wireless sensor networks (WSN) is presented. This ondemand routing protocol minimizes a novel link cost factor which is defined using available energy, end-to-end (E2E) delay and distance from a node to the base station (BS), along with clustering, to effectively route information to the BS. Initially, the nodes are either in idle or sleep mode, but once an event is detected, the nodes near the event become active and start forming sub-networks. Formation of the inactive network into a sub-network saves energy because only a portion of …

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Hdp Based Optimal Control Of A Grid Independent Pv System, Richard L. Welch, Ganesh K. Venayagamoorthy Jan 2006

Hdp Based Optimal Control Of A Grid Independent Pv System, Richard L. Welch, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents an adaptive optimal control scheme for a grid independent photovoltaic (PV) system consisting of a PV collector array, a storage battery, and loads (critical and non-critical loads). The optimal control algorithm is based on the model-free heuristic dynamic programming (HDP), an adaptive critic design (ACD) technique which optimizes the control performance based on a utility function. The HDP critic network is used in a PV system simulation study to train a neurocontroller to provide optimal control for varying PV system output energy and load demands. The emphasis of the optimal controller is primarily to supply the critical …

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Intelligent Optimal Control Of Excitation And Turbine Systems In Power Networks, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

Intelligent Optimal Control Of Excitation And Turbine Systems In Power Networks, 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 and turbine systems. The crucial factors affecting the modern power systems today is voltage control and system stabilization during small and large disturbances. Simulation studies and real-time laboratory experimental studies carried out are described and the results show the successful control of the power system excitation and turbine systems with adaptive and optimal neurocontrol approaches. Performances of the neurocontrollers are compared with the conventional PI controllers for damping under different operating conditions for small and large disturbances.

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International Working Group On Assurance Cases (For Security), S. Guerra, M. Masera, Ann K. Miller, C. B. Weinstock, R. E. Bloomfield Jan 2006

International Working Group On Assurance Cases (For Security), S. Guerra, M. Masera, Ann K. Miller, C. B. Weinstock, R. E. Bloomfield

Electrical and Computer Engineering Faculty Research & Creative Works

Critical systems are aptly named - from electric power to water and gas to the telephone system and the Internet, they're all critical to some aspect of our daily lives. We''re a networked society and as such, it's important to both know whether critical systems are trustworthy and be able to communicate, review, and debate the level of trust achieved in them. In the safety domain, explicit safety cases are increasingly required by law, regulations, and standards. In this article, we outline what a small, international group of experts, spanning various disciplines in safety, security, reliability, and critical infrastructure, been …

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Intelligent Tool For Determining The True Harmonic Current Contribution Of A Customer In A Power Distribution Network, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Marty L. Page, Ronald G. Harley Jan 2006

Intelligent Tool For Determining The True Harmonic Current Contribution Of A Customer In A Power Distribution Network, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Marty L. Page, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Customer loads connected to electricity supply systems may be broadly categorized as either linear or nonlinear. Nonlinear loads inject harmonics into the power network. Harmonics in a power system are classified as either load harmonics or as supply harmonics depending on their origin. The source impedance also impacts the harmonic current flowing in the network. Hence any change in the source impedance is reflected in the harmonic spectrum of the current. This paper proposes a novel method based on Artificial Neural Networks to isolate and evaluate the impact of the source impedance change without disrupting the operation of any load, …

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Nanoporous Zeolite Thin Film-Based Fiber Intrinsic Fabry-Perot Interferometric Sensor For Detection Of Dissolved Organics In Water, Ning Liu, Juan Hui, Cunqiang Sun, Junhang Dong, Luzheng Zhang, Hai Xiao Jan 2006

Nanoporous Zeolite Thin Film-Based Fiber Intrinsic Fabry-Perot Interferometric Sensor For Detection Of Dissolved Organics In Water, Ning Liu, Juan Hui, Cunqiang Sun, Junhang Dong, Luzheng Zhang, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A fiber optic intrinsic Fabry-Perot interferometric (IFPI) chemical sensor was developed by fine-polishing a thin layer of polycrystalline nanoporous MFI zeolite synthesized on the cleaved endface of a single mode fiber. The sensor operated by monitoring the optical thickness changes of the zeolite thin film caused by the adsorption of organic molecules into the zeolite channels. The optical thickness of the zeolite thin film was measured by white light interferometry. Using methanol, 2-propanol, and toluene as the model chemicals, it was demonstrated that the zeolite IPFI sensor could detect dissolved organics in water with high sensitivity.

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Online Training Of A Generalized Neuron With Particle Swarm Optimization, R. Kiran, Ganesh K. Venayagamoorthy, Sandhya R. Jetti Jan 2006

Online Training Of A Generalized Neuron With Particle Swarm Optimization, R. Kiran, Ganesh K. Venayagamoorthy, Sandhya R. Jetti

Electrical and Computer Engineering Faculty Research & Creative Works

Neural networks are used in a wide number of fields including signal and image processing, modeling and control and pattern recognition. Some of the most common type of neural networks is the multilayer perceptrons and the recurrent neural networks. Most of these networks consist of large number of neurons and hidden layers, which results in a longer training time. A Generalized Neuron (GN) has a compact structure and overcomes the problem of long training time. Due to its simple structure and lesser memory requirements, the GN is attractive for hardware implementations. This paper presents the online training of a GN …

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Optimal Design Of Svc Damping Controllers With Wide Area Measurements Using Small Population Based Pso, Ganesh K. Venayagamoorthy, Tridib Kumar Das, Sandhya R. Jetti Jan 2006

Optimal Design Of Svc Damping Controllers With Wide Area Measurements Using Small Population Based Pso, Ganesh K. Venayagamoorthy, Tridib Kumar Das, Sandhya R. Jetti

Electrical and Computer Engineering Faculty Research & Creative Works

Static Var Compensator (SVC) are employed for providing better voltage regulation and transient stability especially for increased power transfer through the transmission lines. In this paper, two SVC damping controllers with single and dual inputs respectively are designed based on wide area measurements of generator speed deviations. A Small Population based Particle Swarm Optimization algorithm (SPPSO) is applied to determine the optimal parameters of the damping controllers for small and large disturbances. Simulation results are provided to show that the effectiveness of the optimal damping controllers on the Kundur''s two-area benchmark power system. Results show the dual input controller further …

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Permutation Coding Technique For Image Recognition Systems, Ernst M. Kussul, Tatiana N. Baidyk, Donald C. Wunsch, Oleksandr Makeyev, Anabel Martin Jan 2006

Permutation Coding Technique For Image Recognition Systems, Ernst M. Kussul, Tatiana N. Baidyk, Donald C. Wunsch, Oleksandr Makeyev, Anabel Martin

Electrical and Computer Engineering Faculty Research & Creative Works

A feature extractor and neural classifier for image recognition systems are proposed. The proposed feature extractor is based on the concept of random local descriptors (RLDs). It is followed by the encoder that is based on the permutation coding technique that allows to take into account not only detected features but also the position of each feature on the image and to make the recognition process invariant to small displacements. The combination of RLDs and permutation coding permits us to obtain a sufficiently general description of the image to be recognized. The code generated by the encoder is used as …

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Fault-Tolerant Control For Sssc Using Neural Networks And Pso, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

Fault-Tolerant Control For Sssc Using Neural Networks And Pso, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Adaptive Distributed Fair Scheduling And Its Implementation In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Jan 2006

Adaptive Distributed Fair Scheduling And Its Implementation 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 is shown through hardware implementation. In contrast to simulation, hardware evaluation provides valuable feedback to protocol and hardware development process. The proposed protocol focuses on quality-of-service (QoS) issues to address flow prioritization. Thus, when nodes access a shared channel, the proposed ADFS allocates the channel bandwidth proportionally to the weight, or priority, of the packet flows. Moreover, ADFS allows for dynamic allocation of network resources with little added overhead. Weights are initially assigned using user specified QoS criteria. These weights are subsequently updated as a function of …

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Calculating Static Field And Charge Distributions Using Full-Wave Boundary Element Methods, Todd H. Hubing, Haixin Ke Jan 2006

Calculating Static Field And Charge Distributions Using Full-Wave Boundary Element Methods, Todd H. Hubing, Haixin Ke

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Density Estimation Using A Generalized Neuron, R. Kiran, Ganesh K. Venayagamoorthy, M. Palaniswami Jan 2006

Density Estimation Using A Generalized Neuron, R. Kiran, Ganesh K. Venayagamoorthy, M. Palaniswami

Electrical and Computer Engineering Faculty Research & Creative Works

Neural networks have been shown to be useful tools for density estimation. However, the training of neural network structures is time consuming and requires fast processors for practical applications. A new method with a generalized neuron (GN) for density estimation is presented in this paper. The GN is trained with the particle swarm optimization algorithm which is known to have fast convergence than the standard backpropagation algorithm. Results are presented to show that the GN can estimate the density functions for distribution functions with different means and variances. This density estimation method can also be applied to the multi-sensor data …

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Echo State Networks For Determining Harmonic Contributions From Nonlinear Loads, Joy Mazumdar, Ganesh K. Venayagamoorthy, Frank C. Lambert, Ronald G. Harley Jan 2006

Echo State Networks For Determining Harmonic Contributions From Nonlinear Loads, Joy Mazumdar, Ganesh K. Venayagamoorthy, Frank C. Lambert, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the application of a new kind of recurrent neural network called Echo State Networks (ESNs) for the problem of measuring the actual amount of harmonic current injected into a power network by a nonlinear load. The interaction between loads connected to a point of common coupling (PCC) is a highly dynamic process. The determination of true harmonic current injection by individual loads is further complicated by the fact that the supply voltage waveform at the PCC is distorted by other loads at the PCC or further upstream and is therefore rarely a pure sinusoid. Harmonics in a …

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Fast Time-Varying Dispersive Channel Estimation And Equalization For 8-Psk Cellular System, Sang-Yick Leong, Jingxian Wu, Chengshan Xiao, Jan C. Olivier Jan 2006

Fast Time-Varying Dispersive Channel Estimation And Equalization For 8-Psk Cellular System, Sang-Yick Leong, Jingxian Wu, Chengshan Xiao, Jan C. Olivier

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel channel-estimation scheme for an 8-PSK enhanced data rates for GSM evolution (EDGE) system with fast time-varying and frequency-selective fading channels is presented. via a mathematical derivation and simulation results, the channel impulse response (CIR) of the fast fading channel is modeled as a linear function of time during a radio burst in the EDGE system. Therefore, a least-squares-based method is proposed along with the modified burst structure for time-varying channel estimation. Given that the pilot-symbol blocks are located at the front and the end of the data block, the LS-based method is able to estimate …

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Intentional Islanding And Adaptive Load Shedding To Avoid Cascading Outages, Badrul H. Chowdhury, H. Manjari Dola Jan 2006

Intentional Islanding And Adaptive Load Shedding To Avoid Cascading Outages, Badrul H. Chowdhury, H. Manjari Dola

Electrical and Computer Engineering Faculty Research & Creative Works

Predetermined islanding scenarios along with automated load shedding schemes are applied once a prospective cascading outage condition is predicted. If required, additional distributed generation at specified locations in the system is also determined. The choice of different islands along with loads to be shed is then made available to the operator so as to be armed for action in case the system security is compromised. Determination of line outages that lead to disastrous consequences, intentional islanding schemes, and load shedding schemes have been explored individually. A plan integrating these defense mechanisms coupled with the possibility of using distributed generation where …

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Novel Sum-Of-Sinusoids Simulation Models For Rayleigh And Rician Fading Channels, Chengshan Xiao, Y. Rosa Zheng, N. C. Beaulieu Jan 2006

Novel Sum-Of-Sinusoids Simulation Models For Rayleigh And Rician Fading Channels, Chengshan Xiao, Y. Rosa Zheng, N. C. Beaulieu

Electrical and Computer Engineering Faculty Research & Creative Works

The statistical properties of Clarke's fading model with a finite number of sinusoids are analyzed, and an improved reference model is proposed for the simulation of Rayleigh fading channels. A novel statistical simulation model for Rician fading channels is examined. The new Rician fading simulation model employs a zero-mean stochastic sinusoid as the specular (line-of-sight) component, in contrast to existing Rician fading simulators that utilize a non-zero deterministic specular component. The statistical properties of the proposed Rician fading simulation model are analyzed in detail. It is shown that the probability density function of the Rician fading phase is not only …

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Predicting Load Harmonics In Three Phase Systems Using Neural Networks, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

Predicting Load Harmonics In Three Phase Systems Using Neural Networks, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a artificial neural network (ANN) based method for the problem of measuring the actual harmonic current injected into a power system network by three phase nonlinear loads without disconnecting any loads from the network. The ANN directly estimates or identifies the nonlinear admittance (or impedance) of the load by using the measured values of voltage and current waveforms. The output of this ANN is a waveform of the current that the load would have injected into the network if the load had been supplied from a sinusoidal voltage source and is therefore a direct measure of load …

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Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu Jan 2006

Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In determining the correct operation of relays of a protection scheme, proper representation of instrument transformers and their behavior in conditions where there can be transient is very critical. This paper presents a simulation model for assessing the transient performance of capacitive voltage transformers (CVTs). In order to test the validity of the developed model, four CVT operational conditions are considered using field data collected from one of the Nigerian electric utility 330/132/33 kV substations. The model simulation results revealed various configuration performance responses that could affect relay protection schemes to different degrees. As expected, the CVT responses showed that …

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Synthesis And Characterization Of Nanocrystalline (Zr₀.₈₄Y₀.₁₆)O₁.₉₂-(Ce₀.₈₅Sm₀.₁₅)O₁.₉₂₅ Heterophase Thin Films, Aniruddha Kulkarni, Alexander Bourandas, Junhang Dong, Paul A. Fuierer, Hai Xiao Jan 2006

Synthesis And Characterization Of Nanocrystalline (Zr₀.₈₄Y₀.₁₆)O₁.₉₂-(Ce₀.₈₅Sm₀.₁₅)O₁.₉₂₅ Heterophase Thin Films, Aniruddha Kulkarni, Alexander Bourandas, Junhang Dong, Paul A. Fuierer, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A new type of nanocrystalline samarium-doped-ceria/yttrium-stabilized-zirconia (SDC/YSZ) heterophase thin film electrolytes was synthesized on MgO and Si substrates by spin coating and thermal treatment of SDC-nanoparticle-incorporated polymeric precursors. In the heterophase films, SDC nanoparticles were uniformly dispersed in a nanocrystalline YSZ matrix. The heterophase structure was stable when fired in air at temperatures up to 850 °C. The nanocrystalline heterophase thin films exhibited electrical conductivities significantly higher than that of the phase-pure YSZ and SDC nanocrystalline thin films at reduced temperatures. The effects of SDC grain size and volume fraction on the electrical conductivity of the heterophase films were also …

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A Closed-Form Expression For Estimating Radiated Emissions From The Power Planes In A Populated Printed Circuit Board, Todd H. Hubing, Hwan-Woo Shim Jan 2006

A Closed-Form Expression For Estimating Radiated Emissions From The Power Planes In A Populated Printed Circuit Board, Todd H. Hubing, Hwan-Woo Shim

Electrical and Computer Engineering Faculty Research & Creative Works

An expression for the maximum intensity of radiated emissions from a rectangular power bus structure has been derived based on an analytical cavity-resonator model. The effect of components mounted on the board is modeled by modifying the propagation constant of the waves within the power bus structure. The radiated field intensity is calculated using the equivalent magnetic current around the edges of the power bus structure together with the modified propagation constant. Measurements of a populated test board show that the derived closed-form expression estimates the level of the maximum radiation intensity with reasonable accuracy.

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A Fault-Tolerant P-Q Decoupled Control Scheme For Static Synchronous Series Compensator, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

A Fault-Tolerant P-Q Decoupled Control Scheme For Static Synchronous Series Compensator, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Control of nonlinear devices in power systems relies on the availability and the quality of sensor measurements. Measurements can be corrupted or interrupted due to sensor failure, broken or bad connections, bad communication, or malfunction of some hardware or software (referred to as missing sensor measurements in this paper). This paper proposes a fault-tolerant control scheme (FTCS) for a static synchronous series compensator (SSSC). This FTCS consists of a sensor evaluation and (missing sensor) restoration scheme (SERS) cascaded with a P-Q decoupled control scheme (PQDC). It is able to provide effective control to the SSSC when single or multiple crucial …

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Ac/Dc Power Systems With Applications In Future Human Habitat On Lunar And Mars Bases, Badrul H. Chowdhury, Sabbir A. Hossain, James T. Lawrence, Sushant Barave Jan 2006

Ac/Dc Power Systems With Applications In Future Human Habitat On Lunar And Mars Bases, Badrul H. Chowdhury, Sabbir A. Hossain, James T. Lawrence, Sushant Barave

Electrical and Computer Engineering Faculty Research & Creative Works

As NASA readies itself for new space exploration initiatives starting with a human return to the Moon by the year 2020 eventually leading to human exploration of Mars, the requirements for a safe, efficient and comprehensive power system to support the exploration missions as well human habitat will become important issues to consider. Certain issues dealing with electric power generation and distribution on board Mars-bound vehicles and those on Lunar and Martian surfaces are described. The requirements for lightweight power generation dictates the use of a high frequency ac machine. Preliminary results of investigating the design of a permanent magnet …

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Creating Cascading Failure Scenarios In Interconnected Power Systems, Badrul H. Chowdhury, Sushant Barave Jan 2006

Creating Cascading Failure Scenarios In Interconnected Power Systems, Badrul H. Chowdhury, Sushant Barave

Electrical and Computer Engineering Faculty Research & Creative Works

The reported catastrophic failures of power systems from different geographical parts of the world often point to cascading outage events of system elements that eventually had led to system blackout. Although the initiating events of these cascading failures may, at times, be avoidable by vegetation management or proper protection settings, the occurrence of such an event as well as the eventual impact cannot always be predicted. There is much debate in the industry whether the operator has enough time to apply countermeasures to avoid blackouts. Besides, the process of determining effective countermeasures cannot be deemed accurate unless a system has …

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Design Of Optimal Pi Controllers For Doubly Fed Induction Generators Driven By Wind Turbines Using Particle Swarm Optimization, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

Design Of Optimal Pi Controllers For Doubly Fed Induction Generators Driven By Wind Turbines Using Particle Swarm Optimization, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

When subjected to transient disturbances in the power grid, the variable frequency converter (VFC) is the most sensitive part in the variable-speed wind turbine generator system (WTGS) equipped with a doubly fed induction generator (DFIG). The VFC is normally controlled by a set of PI controllers. Tuning these PI controllers is a tedious work and it is difficult to tune the PI gains optimally due to the nonlinearity and the high complexity of the system. This paper presents an approach to use the particle swarm optimization algorithm to design the optimal PI controllers for the rotor-side converter of the DFIG. …

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Observability Conditions For Target States With Bearing-Only Measurements In Three-Dimensional Case, Mehdi Ferdowsi Jan 2006

Observability Conditions For Target States With Bearing-Only Measurements In Three-Dimensional Case, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

In target tracking with a passive sensor such as infrared seekers, angle-only information is determined. In this case no information about the range of the target is provided and unobservable system is resulted. This paper studies the observability of discrete time three-dimensional bearing-only target tracking. The target is assumed to be moving in a straight line while a single moving observer (own-ship) measures its relative (elevation and azimuth) bearing angles. By transforming the inherently nonlinear bearing measurements into a pseudo-linear form, a linear Least Squares (LS) estimator is formulated. Observability is then analyzed by studying the solvability of the associated …

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Extended Operation Of Flying Capacitor Multilevel Inverters, Jing Huang, Keith Corzine Jan 2006

Extended Operation Of Flying Capacitor Multilevel Inverters, Jing Huang, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

Recent research in flying capacitor multilevel inverters (FCMIs) has shown that the number of voltage levels can be extended by changing the ratio of the capacitor voltages. For the three-cell FCMI, four levels of operation are expected if the traditional ratio of the capacitor voltages is 1:2:3. However, by altering the ratio, the inverter can operate as a five-, six-, seven-, or eight-level inverter. According to previous research, the eight-level case is referred to as maximally distended (or full binary combination schema) since it utilizes all possible transistor switching states. However, this case does not have enough per-phase redundancy to …

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Optimal Design Of Power System Stabilizers Using A Small Population Based Pso, Ganesh K. Venayagamoorthy, Tridib Kumar Das Jan 2006

Optimal Design Of Power System Stabilizers Using A Small Population Based Pso, Ganesh K. Venayagamoorthy, Tridib Kumar Das

Electrical and Computer Engineering Faculty Research & Creative Works

Power system stabilizers (PSSs) are used to generate supplementary control signals to excitation systems in order to damp out local and inter-area oscillations. In this paper, a modified particle swarm optimization (PSO) algorithm with a small population is presented for the design of optimal PSSs. The small population based PSO (SPPSO) is used to determine the optimal parameters of several PSSs simultaneously in a multi-machine power system. In order to maintain a dynamic search process, the idea of particle regeneration in the population is also proposed. Optimal PSS parameters are determined for the power system subjected to small and large …

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A Comparison Of Diode-Clamped And Cascaded Multilevel Converters For A Statcom With Energy Storage, Ying Cheng, Chang Qian, Mariesa Crow, Steven Pekarek, Stan Atcitty Jan 2006

A Comparison Of Diode-Clamped And Cascaded Multilevel Converters For A Statcom With Energy Storage, Ying Cheng, Chang Qian, Mariesa Crow, Steven Pekarek, Stan Atcitty

Electrical and Computer Engineering Faculty Research & Creative Works

The progression of distributed generation within a bulk power system will lead to the need for greater control of transmission-line power flows. Static synchronous compensators (STATCOMs) provide a power-electronics-based means of embedded control of transmission-line voltage and power flows. The integration of energy storage with a STATCOM can extend traditional STATCOM capabilities to four-quadrant power flow control and transient stability improvement. This paper discusses energy storage systems (ESSs) integrated with conventional and multilevel bidirectional power converters for a hybrid STATCOM/ESS. Conventional, diode-clamped, and cascaded multilevel converter-based STATCOM/ESSs are developed, and their performances for a variety of power system applications are …

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A Non-Isotropic Model For Mobile-To-Mobile Fading Channel Simulations, Y. Rosa Zheng Jan 2006

A Non-Isotropic Model For Mobile-To-Mobile Fading Channel Simulations, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Accurate modeling of the mobile-to-mobile fading channel is critical not only to physical layer transceiver design but also to the design and performance of link and network layers. A two-dimensional nonisotropic scattering model is developed in this paper, which adopts the von Mises probability density function for the angle of departure surrounding the transmitter and the angle of arrival surrounding the receiver. This model includes the isotropic scattering channel and the base-to-mobile channel as special cases. An efficient computer simulation model is also developed to generate the non-isotropic scattering channel impulse responses. Statistical properties of the non-isotropic mobile-to-mobile channels are …

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