Engineering Commons^™

Characterization Of Human Metal Esd Reference Discharge Event And Correlation Of Generator Parameters To Failure Levels-Part I: Reference Event, Ramachandran Chundru, David Pommerenke, Kai Wang, Thomas Van Doren, Jiu Sheng Huang, Federico Centola

Electrical and Computer Engineering Faculty Research & Creative Works

Electrostatic discharge (ESD) generators are used for testing the robustness of electronics toward ESD. Most generators are built in accordance with the IEC 61000-4-2 specifications. Using only a few parameters, this standard specifies the peak current, the rise time and the falling edge. Lacking a transient field specification, test results vary depending on which generator is used, even if the currents are quite similar. Such a specification is needed to improve the test repeatability. As for the current, the specification should be based on a reference human metal ESD event. While keeping the presently set peak current and rise time …

Cause And Effects Of Voltage Collapse -- Case Studies With Dynamic Simulations, Feng Dong, Mariesa Crow, Badrul H. Chowdhury, Levent Acar

Electrical and Computer Engineering Faculty Research & Creative Works

Voltage collapse studies are made to gain an insight into mechanisms that drive a system into collapse. The inter-play of generator controls in local and external areas are explored. Simulations are carried out on a medium sized network by a transient dynamic simulation program. Simulation results help to better understand remediation strategies. The time dependent characteristics of corrective controls are investigated.

Decentralized Neural Network Control Of A Class Of Large-Scale Systems With Unknown Interconnection, Wenxin Liu, Jagannathan Sarangapani, Donald C. Wunsch, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized neural network (DNN) controller is proposed for a class of large-scale nonlinear systems with unknown interconnections. The objective is to design a DNN for a class of large-scale systems which do not satisfy the matching condition requirement. The NNs are used to approximate the unknown subsystem dynamics and the interconnections. The DNN is designed using the back stepping methodology with only local signals for feedback. All of the signals in the closed loop (system states and weights estimation errors) are guaranteed to be uniformly ultimately bounded and eventually converge to a compact set.

The Pcb Level Esd Immunity Study By Using 3 Dimension Esd Scan System, Kai Wang, David Pommerenke, Jian Min Zhang, Ramachandran Chundru

Electrical and Computer Engineering Faculty Research & Creative Works

The use of high-speed logic makes modern electronic systems highly susceptible to electrostatic discharge (ESD). Because of their wider bandwidth, faster digital devices are more susceptible to high frequency ESD transient fields. In the analysis of ESD problems, an exact knowledge of the affected PINs and nets is essential for an optimal solution. A three dimensional ESD scanning system, which has been developed to record the ESD susceptibility map for a printed circuit board, is presented, and the mechanisms that the ESD event couples into the digital devices is studied.

The Robustness Of Resource Allocation In Parallel And Distributed Computing Systems, Shoukat Ali, Howard Jay Siegel, A. A. Maciejewski

Electrical and Computer Engineering Faculty Research & Creative Works

This paper gives an overview of the material to be discussed in the invited keynote presentation by H. J. Siegel. Performing computing and communication tasks on parallel and distributed systems involves the coordinated use of different types of machines, networks, interfaces, and other resources. Decisions about how best to allocate resources are often based on estimated values of task and system parameters, due to uncertainties in the system environment. An important research problem is the development of resource management strategies that can guarantee a particular system performance given such uncertainties. We have designed a methodology for deriving the degree of …

Unmanned Vehicle Navigation Using Swarm Intelligence, Sheetal Doctor, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Unmanned vehicles are used to explore physical areas where humans are unable to go due to different constraints. There have been various algorithms that have been used to perform this task. This paper explores swarm intelligence for searching a given problem space for a particular target(s). The work in this paper has two parts. In the first part, a set of randomized unmanned vehicles are deployed to locate a single target. In the second part, the randomized unmanned vehicles are deployed to locate various targets and are then converged at one of targets of a particular interest. Each of the …

Via Coupling Within Power-Return Plane Structures Considering The Radiation Loss, J. 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. The radiation loss is incorporated into a complex propagating wavenumber as an artificial loss mechanism. The quality factors associated with the 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 PCBs. Measurements are performed to validate the effectiveness of the model.

Modeling The Wave Propagation Properties Of Power Cables Using Numerical Simulations, R. Papazyan, David Pommerenke, R. Eriksson

Electrical and Computer Engineering Faculty Research & Creative Works

The high frequency properties of coaxial power cables are modeled using time- and frequency-domain numerical simulations. This is required due to the complex helical structure of the outer metallic screen. It is established that this screen design causes a dependence of the cable characteristics on the surrounding medium

Radiated Emissions From Populated Printed Circuit Boards Due To Power Bus Noise, Hwan-Woo Shim, Todd H. Hubing, Yan Fu

Electrical and Computer Engineering Faculty Research & Creative Works

Previous studies have demonstrated that power plane pairs in a printed circuit board are capable of generating significant radiated emissions at resonance frequencies if these resonances are not damped by material or component losses. The paper shows that board resonances may be readily damped by component losses. However, radiated emissions from a damped power bus may still exceed FCC or CISPR limits over a broad band of frequencies.

Robust Near-Field Adaptive Beamforming With Distance Discrimination, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a robust near-field adaptive beamformer for microphone array applications in small rooms. Robustness against location errors is crucial for near-field adaptive beamforming due to the difficulty in estimating near-field signal locations especially the radial distances. A near-field regionally constrained adaptive beamformer is proposed to design a set of linear constraints by filtering on a low rank subspace of the near-field signal over a spatial region and frequency band such that the beamformer response over the designed spatial-temporal region can be accurately controlled by a small number of linear constraint vectors. The proposed constraint design method is a …

Indirect Adaptive Control For Synchronous Generator: Comparison Of Mlp/Rbf Neural Networks Approach With Lyapunov Stability Analysis, Jung-Wook Park, Ronald G. Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares two indirect adaptive neurocontrollers, namely a multilayer perceptron neurocontroller (MLPNC) and a radial basis function neurocontroller (RBFNC) to control a synchronous generator. The different damping and transient performances of two neurocontrollers are compared with those of conventional linear controllers, and analyzed based on the Lyapunov direct method.

Data Mining Of Substation Relay Data, Badrul H. Chowdhury, Mythili Chaganti

Electrical and Computer Engineering Faculty Research & Creative Works

Data mining aims to make sense of data by revealing meaningful relationships. This paper discusses data mining techniques applied to data recorded by over current relays at several substations. The purpose is to classify faults, verify relay settings and determine fault induced trip per substations. One of the most demanding tasks at hand is to study the data residing in the relays on a statistical basis. C4.5 approach of data mining (decision tree induction) is discussed in this paper.

Detection Of Basal Cell Carcinoma Using Electrical Impedance And Neural Networks, Rohit Dua, Daryl G. Beetner, William V. Stoecker, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Variations in electrical impedance over frequency might be used to distinguish basal cell carcinoma (BCC) from benign skin lesions, although the patterns that separate the two are nonobvious. Artificial neural networks (ANNs) may be good pattern classifiers for this application. A preliminary study to show the potential of neural networks to distinguish benign from malignant skin lesions using electrical impedance is presented. Electrical impedance was measured in vivo from 1 kHz to 1 MHz at five virtual depths on 18 BCC and 16 benign or premalignant lesions. A feed-forward neural network was trained using back propagation to classify these lesions. …

Discrete-Time Neural Network Output Feedback Control Of Nonlinear Systems In Non-Strict Feedback Form, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive neural network (NN)-based output feedback controller is proposed to deliver a desired tracking performance for a class of discrete-time nonlinear systems, which is represented in non-strict feedback form. The NN backstepping approach is utilized to design the adaptive output feedback controller consisting of: 1) a NN observer to estimate the system states with the input-output data, and 2) two NNs to generate the virtual and actual control inputs, respectively. The non-causal problem in the discrete-time backstepping design is avoided by using the universal NN approximator. The persistence excitation (PE) condition is relaxed both in the NN observer and …

Dynamic Optimization Of A Multimachine Power System With A Facts Device Using Identification And Control Objectnets, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This work presents a novel technique for dynamic optimization of the electric power grid using brain-like stochastic identifiers and controllers called ObjectNets based on neural network architectures with recurrence. ObjectNets are neural network architectures developed to identify/control a particular object with a specific objective in hand. The IEEE 14 bus multimachine power system with a FACTS device is considered in this paper. The paper focuses on the combined minimization of the terminal voltage deviations and speed deviations at the generator terminals and the bus voltage deviation at the point of contact of the FACTS device to the power network. Simulation …

Ergodic Capacity Of Doubly Selective Rayleigh Fading Mimo Channels, Chengshan Xiao, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

The ergodic capacity is investigated for doubly selective (frequency selective and time varying) MIMO Rayleigh fading channels. A closed form formula is derived that quantifies the effect of the ISI fading on the ergodic capacity into an ISI degradation factor. It is discovered that, in general frequency selective MIMO channels, the inter-tap correlations of the ISI fading will reduce the ergodic capacity comparing to the frequency flat fading channel. Only in the special case when the ISI fading does not have inter-tap correlations will the ergodic capacity be the same as that of the frequency flat channel. This new formula …

Evolutionary Algorithms, Markov Decision Processes, Adaptive Critic Designs, And Clustering: Commonalities, Hybridization And Performance, Donald C. Wunsch, Samuel A. Mulder

Electrical and Computer Engineering Faculty Research & Creative Works

We briefly review and compare the mathematical formulation of Markov decision processes (MDP) and evolutionary algorithms (EA). In so doing, we observe that the adaptive critic design (ACD) approach to MDP can be viewed as a special form of EA. This leads us to pose pertinent questions about possible expansions of the methodology of ACD. This expansive view of EA is not limited to ACD. We discuss how it is possible to consider the powerful chained Lin Kernighan (chained LK) algorithm for the traveling salesman problem (TSP) as a degenerate case of EA. Finally, we review some recent TSP results, …

Manipulation Of Microenvironment With A Built-In Electrochemical Actuator In Proximity Of A Dissolved Oxygen Microsensor, Chang-Soo Kim, J. O. Fiering, C. W. Scarantino, H. Troy Nagle, Chae-Hyang Lee, Stefan Ufer

Electrical and Computer Engineering Faculty Research & Creative Works

Biochemical sensors for continuous monitoring require dependable periodic self diagnosis with acceptable simplicity to check its functionality during operation. An in-situ self-diagnostic technique for a dissolved oxygen microsensor is proposed in an effort to devise an intelligent microsensor system with an integrated electrochemical actuation electrode. With a built-in platinum microelectrode that surrounds the microsensor, two kinds of microenvironments, called the oxygen-saturated or oxygen-depleted phases, can be created by water electrolysis, depending on the polarity. The functionality of the microsensor can be checked during these microenvironment phases. The polarographic oxygen microsensor is fabricated on a flexible polyimide substrate (Kapton) and the …

Navigation Of Mobile Sensors Using Pso And Embedded Pso In A Fuzzy Logic Controller, Ganesh K. Venayagamoorthy, Sheetal Doctor

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents novel structures for optimization and communication of a swarm of mobile sensors or robots for maximizing local and global tasks such as firefighting, landmine detection, radioactivity detection, etc. The navigation of the sensors is carried out using two strategies. The first strategy is based on particle swarm optimization (PSO) and the second strategy is based on a swarm of fuzzy logic based controllers. In addition, the membership functions and the rules of the fuzzy logic controller (FLC) are optimized using the PSO algorithm. Navigation of mobile sensors is considered in this paper to locate desirable target sources …

Neural Network Controller For Manipulation Of Micro-Scale Objects, Vijayakumar Janardhan, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel reinforcement learning-based neural network (RLNN) controller is presented for the manipulation and handling of micro-scale objects in a microelectromechanical system (MEMS). In MEMS, adhesive, surface tension, friction and van der Waals forces are dominant. Moreover, these forces are typically unknown. The RLNN controller consists of an action NN for compensating the unkoown system dynamics, and a critic NN to tune the weights of the action NN. Using the Lyapunov approach, the uniformly ultimate houndedness (UUB) of the closed-loop tracking error and weight estimates are shown by using a novel weight updates. Simulation results are presented to substantiate the …

New External Neuro-Controller For Series Capacitive Reactance Compensator In A Power Network, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The controllable capacitive reactance can be used as the input variable for the external controller of a series capacitive reactance compensator (SCRC) to improve the damping of low-frequency oscillations of the rotor angle and active power in a power system. Conventional linear PI controllers are tuned for best performance at one specific operating point of the nonlinear power system. At other operating point its performance degrades. Nonlinear optimal neuro-controllers are able to overcome this degradation. In this paper, the dual heuristic dynamic programming (DHP) optimization algorithm is applied to design an external nonlinear optimal neuro-controller for the SCRC. Simulation studies …

Fantasy And The Concert Hall: Musical Performance In The Electroacoustic Age, Matthew Malsky

Reconstruction: Studies in Contemporary Culture

[First paragraph]

In 1941, the famously despondent Theodor Adorno worried about the detrimental effects of radio broadcast upon the symphony. He theorized that much of value was lost when listeners experienced an orchestral performance of a composition in symphonic form through its electronic transmission to their kitchens rather than in a concert hall. Based upon empirical research done in collaboration with Paul Lazarsfeld and the Princeton Radio Research Project, he argued that the presence of music was lost to the radio listener, and with it a part of music's auratic spell, its uniqueness in time and place, its ritual, cultish …

A Nonlinear Model For Prediction Of Dynamic Coefficients In A Hydrodynamic Journal Bearing, Jerzy T. Sawicki, T.V.V.L. N. Rao

Mechanical Engineering Faculty Publications

This paper investigates the variation of nonlinear stiffness and damping coefficients in a journal orbit with respect to equilibrium position. The journal orbit is obtained by the combined solution of equations of motion and Reynolds equation. In the linearized dynamic analysis, dynamic pressure is written as a perturbation of static pressure and pressure gradients at equilibrium position. However, in order to obtain nonlinear dynamic coefficients about equilibrium position, the dynamic pressure gradients in the orbit are also written as the first order perturbation of static pressure gradients and higher order pressure gradients for displacement and velocity perturbations. The dynamic coefficients …

Cs 302-01: Client Server Databases, Karen Meyer

Computer Science & Engineering Syllabi

No abstract provided.

Cs/Mth 317/517: Numerical Methods For Digital Computers - Ii, Ronald F. Taylor

Computer Science & Engineering Syllabi

Continuation of CS/MTH/316/516. Introduction to numerical methods used in the sciences. Methods for solving matrix eigenvalue problems, initial value and boundary value problem for ordinary differential equations (ODEs). Study of standard types of partial differential equations (PDEs) with applications. Solution techniques for systems of nonlinear equations. Discussion of sources of errors in numerical methods. Special topics and applications presented as schedule permits. 4 credit hours. Prerequisites: CS 316, MTH 233, 253, or 355. Programming course prerequisites: EGR 153 or CEG 220 or CS 241.

Sympathetic Vibration Due To Co-Ordinated Crowd Jumping, Christopher Y. Tuan

Civil Engineering Faculty Publications

In assembly structures or places where crowds may gather such as dance halls, theaters, gymnasia and stadia, the loading is almost entirely caused by human activities. Structural resonance or near resonance and the resulting vibrations causing discomfort of spectators have often been observed during a rock concert or a sporting event. Recent research efforts have focused on developing load models to quantify the dynamic loading effects induced by individuals and groups up to 40 people. The lack of coherence of motion from a large crowd, the so-called ‘‘group effect’’, has been quantified based on simulations. The simulation results and the …

Magneto-Acoustic Emission Analysis Of Microstructural Change In Aisi 430 And Aisi 304 Stainless Steel, Denis O'Sullivan

Theses

Magneto-acoustic emission (MAE) is a relatively new non-destructive detection technique. Its working principle is based on Barkhausen discontinuities and magnetostriction within a ferromagnetic material that is subjected to a varying magnetic field. Magneto-acoustic emission (MAE) and magnetic Barkhausen noise (MBN) sensing techniques were developed and employed to characterise plastically deformed and heat-treated AISI 430 ferritic stainless steel and AISI 304 austenitic stainless steel samples. A new waveform measurement parameter for magneto-acoustic emission was developed called MAE (Absolute “energy”).

Both MAE and MBN were found to decrease with increasing plastic deformation of AISI 430. MAE (Absolute “energy”) and MBN (RMS) were …

Dynamic Sensor Management Using Multi Objective Particle Swarm Optimizer, Kalyan Veeramachaneni, Lisa Ann Osadciw

Electrical Engineering and Computer Science - All Scholarship

This paper presents a Swarm Intelligence based approach for sensor management of a multi sensor networks. Alternate sensor configurations and fusion strategies are evaluated by swarm agents, and an optimum configuration and fusion strategy evolves. An evolutionary algorithm, particle swarm optimization, is modified to optimize two objectives: accuracy and time. The output of the algorithm is the choice of sensors, individual sensor's thresholds and the optimal decision fusion rule. The results achieved show the capability of the algorithm in selecting optimal configuration for a given requirement consisting of multiple objectives.

Solution Of Time Domain Pmchw Formulation For Transient Electromagnetic Scattering From Arbitrarily Shaped 3-D Dielectric Objects, Baek Ho Jung, T. K. Sarkar, Y.-S. Chung

Electrical Engineering and Computer Science - All Scholarship

In this paper, we analyze the transient electromagnetic response from three-dimensional (3-D) dielectric bodies using a time domain PMCHW (Poggio, Miller, Chang, Harrington, Wu) integral equation. The solution method in this paper is based on the Galerkin’s method that involves separate spatial and temporal testing procedures. Triangular patch basis functions are used for spatial expansion and testing functions for arbitrarily shaped 3-D dielectric structures. The time domain unknown coefficients of the equivalent electric and magnetic currents are approximated by a set of orthonormal basis functions that are derived from the Laguerre functions. These basis functions are also used as the …

University Of Nevada, Las Vegas Transmutation Research Program Annual Report Academic Year 2003-2004, Anthony Hechanova, Elizabeth Johnson, Gary Cerefice

Transmutation Research Program Reports (TRP)

It is my pleasure to present the UNLV Transmutation Research Program’s third annual report that highlights the academic year 2003 – 2004. Supporting this document are the many technical reports and scientific papers that have been generated over the past three years.

In the third year of our program, we experienced infrastructure growth despite a decreasing budget. This past year we continued into the final phases of the initial 16 independent student research tasks started in 2001 and 2002, supporting 45 graduate students and 11 undergraduates in 6 academic departments across the UNLV scientific and engineering communities during the academic …