Digital Commons Network^™

Normalized Natural Gradient Adaptive Filtering For Sparse And Nonsparse Systems, Steven L. Grant, S.C. Douglas

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a class of normalized natural gradient algorithms (NNG) for adaptive filtering tasks. Natural gradient techniques are useful for generating relatively simple adaptive filtering algorithms where the space of the adaptive coefficients is curved or warped with respect to Euclidean space. The advantage of normalizing gradient adaptive filters is that constant rates of convergence for signals with wide dynamic ranges may be achieved. We show that the so-called proportionate normalized least mean squares (PNLMS) algorithm, an adaptive filter that converges quickly for sparse solutions, is in fact an NNG on a certain parameter space warping. We also show …

Comparison Of Mlp And Rbf Neural Networks Using Deviation Signals For On-Line Identification Of A Synchronous Generator, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares the performances of a multilayer perceptron network (MLPN) and a radial basis function network (RBFN) for the online identification of the nonlinear dynamics of a synchronous generator. Deviations of signals from their steady state values are used. The computational complexity required to process the data for online training, generalization and online global minimum testing are investigated by time-domain simulations. The simulation results show that, compared to the MLPN, the RBFN is simpler to implement, needs less computational memory, converges faster and global minimum convergence is achieved even when operating conditions change.

Development Of A Program For Numerical Analysis Of Microwave Radio Links Under Different Conditions, M. Can, Sergey Kharkovsky

Electrical and Computer Engineering Faculty Research & Creative Works

Numerical analysis of system power budget is performed for radio link design and transmission planning purposes in cellular networks. The behavior of three different frequencies; 10.5 GHz, 23 GHz and 38 GHz is examined under the influence of such parameters like transmitter power output level, rain rate, fog density, distance, polarization type, antenna radius, temperature, foliage depth and etc. Received power levels are measured, calculated and reported for different radio link types and environmental conditions. A new program is developed in order to carry out system power budget analysis and design better microwave radio links. Measured and calculated values are …

Esd Currents And Fields On The Vcp And The Hcp Modeled Using Quasi-Static Approximations, David Pommerenke, Wang Kai, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The horizontal coupling plane (HCP) and the vertical coupling plane (VCP) are essential elements of the standardized electrostatic discharge (ESD) test. They are used for testing the robustness of equipment against indirect (nearby) discharges. This article analyzed the current and the fields on the HCP and the VCP using plane wave, transmission line, quasi-static theory. The objective is to illustrate the dominating physical processes on these planes. The work is based on measurements of the transient currents and fields using broadband sensors.

Multilevel Voltage-Source Duty-Cycle Modulation: Analysis And Implementation, Keith Corzine, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

Multilevel converters have become increasingly popular due to high power quality, high-voltage capability, low switching losses, and low electromagnetic compatibility concerns. Considering these advantages, the multilevel converter is a suitable candidate for implementation of future naval ship propulsion systems. This paper focuses on modulation techniques for the multilevel converter. In particular, a novel voltage-source method of multilevel modulation is introduced and compared to existing methods. The proposed method is discrete in nature and can therefore be readily implemented on a digital signal processor. The method is also readily extendable to any number of voltage levels. Results of experimental implementation are …

Second-Order Statistical Properties Of The Wss Jakes' Fading Channel Simulator, Chengshan Xiao, Y. Rosa Zheng, N. C. Beaulieu

Electrical and Computer Engineering Faculty Research & Creative Works

An improved Jakes' (1994) fading channel simulator was proposed by Pop and Beaulieu (see ibid., vol.49, p.699-708, Apr. 2001) to eliminate the stationarity problem occurring in Jakes' original design. In this paper, second-order statistical properties of the improved Jakes' simulator are analyzed. Consistent with Pop and Beaulieu's caution about high-order statistics of the simulator, it is proved that some second-order statistics of both the quadrature components and the envelope do not match the desired ones even if the number of sinusoids approaches infinity. Therefore, care must be taken when the simulator is employed to evaluate algorithms and systems.

Interactive Virtual Laboratory For Experience With A Smart Bridge Test, Elizabeth C. Eckhoff, Vicki M. Eller, Steve Eugene Watkins, Richard Hall

Electrical and Computer Engineering Faculty Research & Creative Works

Virtual laboratory experiments can be cost effective, convenient instructional resources that have appeal to a wide range of learning styles. Expensive, time-consuming laboratory tests can be experienced repeatedly and remotely using interactive simulations and original video footage or animations. A virtual experiment can incorporate meaningful exercises, procedural options, and background hyperlinks to create a comprehensive "hands on" environment. Also, it may be used as preliminary training for the actual experiment.

An interactive LabVIEW-based laboratory for a load test simulation of an existing demonstration bridge was created. This smart truss bridge is instrumented with fiber optic strain sensors situated on the …

The Changing Roles Of Analog And Digital Signal Processing In Cmos Image Sensors, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Throughout the years digital signal processing has been encroaching more and more into what had previously been exclusive analog circuit domains. Here we briefly summarize various lines of research in CMOS imaging sensoring technology paying special attention to the gradual transition from analog to digital processing. The transition from continuous-time continuous-value pixels to digital (discrete-time binary-value) pixels could be viewed as the natural final step in the evolution of these imaging circuits in order to achieve wide dynamic range with acceptable signal to noise ratio. After data is read off a digital pixel imager chip, digital signal processing is required …

Reducing Power Bus Impedance At Resonance With Lossy Components, Todd H. Hubing, Theodore M. Zeeff

Electrical and Computer Engineering Faculty Research & Creative Works

Power bus structures in printed circuit boards with solid power and ground planes exhibit resonances. When the power bus is resonant, the power bus impedance can increase dramatically. This paper explores the effect of component equivalent series resistance (ESR) on power bus resonances. General guidelines for selecting an optimum ESR are provided and are supported by laboratory measurements and numerical simulations.

Finite-Element Modeling Of Coaxial Cable Feeds And Vias In Power-Bus Structures, Hao Wang, Yun Ji, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents three different models that can be used to represent coaxial cable feeds or vias in printed circuit board power-bus structures. The probe model represents a coaxial feed or via as a current filament with unknown radius. The coaxial-cable model enforces an analytical field distribution at the cable opening or via clearance hole. The strip model employs the equivalent radius concept to represent cylindrical feeds and vias as rectangular strips. Although the strip model is functionally equivalent to two closely positioned probe models, it accurately represents the conductor radius and is more accurate in situations where the via …

Increased Mfcc Filter Bandwidth For Noise-Robust Phoneme Recognition, Mark D. Skowronski, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Many speech recognition systems use mel-frequency cepstral coefficient (MFCC) feature extraction as a front end. In the algorithm, a speech spectrum passes through a filter bank of mel-spaced triangular filters, and the filter output energies are log-compressed and transformed to the cepstral domain by the DCT. The spacing of filter bank center frequencies mimics the known warped-frequency characteristics of the human auditory system, yet the bandwidths of these filters are not chosen through biological inspiration. Instead, they are set by aligning endpoints of the triangle, which is itself an arbitrary shape. It is surprising that for such a popular speech …

An Expert System Architecture To Detect System-Level Automotive Emc Problems, Sreeniwas Ranganathan, Daryl G. Beetner, R. Wiese, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Improving EMC in automobiles requires methods to detect potential problems early in the design process. Issues involved in the development of a system-level automotive EMC expert system are explored. The proposed system would help identify problems with radiation and immunity, crosstalk, placement of modules, component grounding and EMC testing. The architecture of the expert system has been developed. The system architecture is designed to allow rapid analysis of automobile designs, to point out potential problems and to suggest possible solutions.

Speedup Of Self-Timed Digital Systems Using Early Completion, Scott C. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

An Early Completion technique is developed to significantly increase the throughput of NULL Convention self-timed digital systems without impacting latency or compromising their self-timed nature. Early Completion performs the completion detection for registration stage i at the input of the register, instead of at the output of the register as in standard NULL Convention Logic. This method requires that the single-rail completion signal from registration stage i+1 , Ko i+1 , be used as an additional input to the completion detection circuitry for registration stage i , to maintain self-timed operation. However, Early Completion does necessitate an assumption of equipotential …

Development Of A Testbed For Design And Evaluation Of Power Electronic Based Systems, S. Pekarek, J. Tichenor, N. Benavides, A. Koenig, H. Wang, Scott D. Sudhoff, B. Kuhn, S. Glover, D. Aliprantis, J. Byoun, J. Sauer

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a detailed technical description of a new hardware-based integrated power system testbed is presented. The testbed consists of an AC generation and propulsion system that is coupled to a DC zonal distribution system. A primary objective of the testbed is to provide a resource to the academic and industrial community by providing a non-proprietary system on which to demonstrate controls, survivability algorithms, and validate computer-aided design (CAD) tools. Copyright © 2002 Society of Automotive Engineers, Inc.

On The Interior Resonance Problem When Applying A Hybrid Fem/Mom Approach To Model Printed Circuit Boards, Yun Ji, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid finite element method/method of moments (FEM/MoM) technique is used to analyze a printed circuit board power bus structure where the source and observation points are in the near field. The FEM is used to model the lossy region between the planes of the board including the source. The MoM is used to model the region outside the planes and provide a radiation boundary condition to terminate the FEM mesh. Numerical results for a bridged power bus structure are compared with measurements. A nonphysical interior resonance of the electric field integral equation is observed. The problem can be avoided …

On The Modeling Of A Gapped Power-Bus Structure Using A Hybrid Fem/Mom Approach, Yun Ji, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid finite-element-method/method-of-moments (FEM/MoM) approach is applied to the analysis of a gapped power-bus structure on a printed circuit board. FEM is used to model the details of the structure. MoM is used to provide a radiation boundary condition to terminate the FEM mesh. Numerical results exhibit significant errors when the FEM/MoM boundary is chosen to coincide with the physical boundary of the board. These errors are due to the inability of hybrid elements on the boundary to enforce the correct boundary condition at a gap edge in a strong sense. A much better alternative is to extend the MoM …

Power Bus Isolation Using Power Islands In Printed Circuit Boards, J. Chen, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Power islands are often employed in printed circuit board (PCB) designs to alleviate the problem of power bus noise coupling between circuits. Good isolation can be obtained over a wide frequency band due to the large series impedance provided by the gap between the power islands. However, power bus resonances may degrade the isolation at high frequencies. The amount of isolation also depends on the type of connection between power islands and the components on the board. This paper experimentally investigates the effectiveness of several power island structures up to 3.0 GHz

Restoration Of The Lorentzian And Debye Curves Of Dielectrics And Magnetics For Fdtd Modeling, Marina Koledintseva, Konstantin Rozanov, James L. Drewniak, Gabriele Di Fazio

Electrical and Computer Engineering Faculty Research & Creative Works

The algorithms of extracting the Lorentzianand Debye-curve parameters of dielectric and magnetic materials from the results of measurements at several frequency points are presented. These algorithms are based on an analytical solution of systems of non-linear equations with physical constraints that follow from the fundamental principle of causality. The extracted parameters are useful for FDTD modeling of electromagnetic structures containing such dispersive media. Some examples are presented.

A Cascaded Converter-Based Statcom With Energy Storage, Chang Qian, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Due to their advantages in high power applications, multi-level converters have been introduced to flexible AC Transmission Systems (FACTS) to enhance power transmission system operation. Although several multi-level StatCom topologies have been proposed to verify the high performance of multi-level converters used in reactive power compensation, they are not capable of controlling active power flow. To make multi-level converters more flexible and effective for active power flow control, energy storage systems, such as flywheels and batteries are incorporated into StatComs. In this paper, battery energy storage systems (BESS) are incorporated into a cascaded converter-based StatCom to implement both active and …

A Diode-Clamped Multi-Level Inverter For The Statcom/Bess, Cheng Ying, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Flexible AC transmission systems (FACTS) are potentially becoming more flexible and more economical local controllers in the power system. The integration of traditional FACTS devices with energy storage system (ESS) will increase FACTS device functionality. The voltage-sourced inverter is an important part of many FACTS devices, such as the StatCom and SSSC. Considerable research has been done on 2-level inverter usage in FACTS. Multilevel inverters, however, can improve the voltage quality and reduce the voltage stress on the power electronic devices. This paper uses a diode-clamped multilevel inverter in the StatCom/BESS. The multilevel inverter switching strategy and output voltage model …

Adaptive Critic Based Optimal Neurocontrol For Synchronous Generator In Power System Using Mlp/Rbf Neural Networks, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel optimal neurocontroller that replaces the conventional controller (CONVC),which consists of the automatic voltage regulator (AVR) and turbine governor, to control a synchronous generator in a power system using a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN). The heuristic dynamic programming (HDP) based on the adaptive critic design (ACD) technique is used for the design of the neurocontroller. The performance of the MLPN based HDP neurocontroller (MHDPC) is compared with the RBFN based HDP neurocontroller (RHDPC) for small as well as large disturbances to a power system, and they are …

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

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of an optimal neurocontroller that replaces the conventional automatic voltage regulator (AVR) and the turbine governor for a turbogenerator connected to the power grid. The neurocontroller design uses a novel technique based on the adaptive critic designs (ACDs), specifically on heuristic dynamic programming (HDP) and dual heuristic programming (DHP). Results show that both neurocontrollers are robust, but that DHP outperforms HDP or conventional controllers, especially when the system conditions and configuration change. This paper also shows how to design optimal neurocontrollers for nonlinear systems, such as turbogenerators, without having to do continually online training of …

Counterexample Of A Claim Pertaining To The Synthesis Of A Recurrent Neural Network, Xindi Cai, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Recurrent neural networks have received much attention due to their nonlinear dynamic behavior. One such type of dynamic behavior is that of setting a fixed stable state. This paper shows a counterexample to the claim of A.N. Michel et al. (IEEE Control Systems Magazine, vol. 15, pp. 52-65, Jun. 1995), that "sparse constraints on the interconnecting structure for a given neural network are usually expressed as constraints which require that pre-determined elements of T [a real n×n matrix acting on a real n-vector valued function] be zero", for the synthesis of sparsely interconnected recurrent neural networks.

Gunn Oscillators Based On Shielded Dielectric Resonators With Mechanical Frequency Tuning, Sergey Kharkovsky, V. I. Lutsenko, I. V. Lutsenko, V. K. Korneenkov, A. E. Kogut

Electrical and Computer Engineering Faculty Research & Creative Works

The features of Gunn oscillators based on shielded dielectric resonators with whispering gallery modes and ray oscillations are investigated. Their comparative analysis for oscillators with different dielectric resonant structures is carried out.

High Q Shielded Dielectric Resonator -- The Basis Of Stable Mm-Waves Generator, V. V. Kutuzov, Sergey Kharkovsky, V. A. Solodovnik, K. A. Kutuzov

Electrical and Computer Engineering Faculty Research & Creative Works

High Q-factor whispering gallery modes which are excited in a shielded hemispherical dielectric resonator by an external signal or Gunn diode are investigated. Their application as modes of an oscillator with high frequency stability is proposed. The power of the output signal and frequency tuning of an oscillator based on the investigated resonator are measured.

Full Binary Combination Schema For Floating Voltage Source Multilevel Inverters, Xiaomin Kou, Keith Corzine, Yakov L. Familiant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents schema of operation for floating voltage source multilevel inverters. The primary advantage of the proposed schema is that the number of voltage levels (and thus power quality) can be increased for a given number of semiconductor devices when compared to the conventional "flying capacitor" topology. However, the new schema requires fixed floating sources instead of capacitors and therefore is more suitable for battery power applications such as electric vehicles, flexible AC transmission systems and submarine propulsion. Alternatively transformer/rectifier circuits may be used to supply the floating sources in a similar way to cascaded H-bridge inverters. Computer simulation …

Analysis Of A Four-Level Dc/Dc Buck Converter, Keith Corzine, J. Yuen, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a four-level DC/DC buck power converter is introduced. The primary application for this converter is to regulate the center capacitor voltage in a four-level inverter system. The steady-state and average-value models for the proposed converter are developed and compared in simulation. The converter was constructed in the laboratory and verified on a four-level motor drive system. It was shown that the four-level DC/DC converter provides capacitor voltage balancing and allows higher output voltage utilization from the inverter.

Two-Dimensional Fast Evanescent Wave Algorithm, W. C. Chew, L. (Lijun) J. Jiang, S. Velamparambil

Electrical and Computer Engineering Faculty Research & Creative Works

A new fast evanescent wave algorithm (FEWA) is introduced in the two-dimensional (2-D) case. It expands the Green's function into propagating waves and directional evanescent waves. Applying the evanescent wave correction technique, a procedure similar to the traditional MLFMA can be expedited. No buffer region is necessary anymore, and fewer translators are needed. Numerical examples are given to show the features of this method.

Energy Storage Systems For Advanced Power Applications, Aysen Arsoy, Yilu Liu, Paul F. Ribeiro, Brian K. Johnson, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

While energy storage technologies do not represent energy sources, they provide valuable added benefits to improve stability power quality, and reliability of supply. Battery technologies have improved significantly in order to meet the challenges of practical electric vehicles and utility applications. Flywheel technologies are now used in advanced nonpolluting uninterruptible power supplies. Advanced capacitors are being considered as energy storage for power quality applications. Superconducting energy storage systems are still in their prototype stages but receiving attention for utility applications. The latest technology developments, some performance analysis, and cost considerations are addressed. This paper concentrates on the performance benefits of …

A Novel Neural Oscillator And Its Implementation In Analog Vlsi, Qiang Luo, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel neural oscillator model that is inspired by biological oscillation models and is easily implemented in subthreshold analog CMOS VLSI. The proposed model uses local coupling among neuron units. Synchrony and information propagation are demonstrated in chains and rings of the oscillators. © 2001 IEEE.