Engineering Commons^™

Modern Control Techniques For Induction Machines In High-Performance Adjustable-Speed Drives, Pat Cronin

Theses

Induction Motors (IM’s) are increasingly being considered for and used in high-performance motor drive (HPMD) systems. Their application has only gained acceptance since the 1970’s with the advent of vector control, microprocessors and improvements in power converter technology. D.C. motors were traditionally the preferred choice in HPMD systems. The main reasons for IM acceptance in HPMD systems are ruggedness, durability, low maintenance, cost, and small size by comparison with D.C. motors.

Alternating current asynchronous motors of the IM type are considered to be the universal workhorses of the manufacturing industry. It has been estimated that they are used in seventy …

Iddq Testing Of A Cmos 10-Bit Charge Scaling Digital-To-Analog Converter, Srinivas Rao Aluri

LSU Master's Theses

This work presents an effective built-in current sensor (BICS), which has a very small impact on the performance of the circuit under test (CUT). The proposed BICS works in two-modes the normal mode and the test mode. In the normal mode the BICS is isolated from the CUT due to which there is no performance degradation of the CUT. In the testing mode, our BICS detects the abnormal current caused by permanent manufacturing defects. Further more our BICS can also distinguish the type of defect induced (Gate-source short, source-drain short and drain-gate short). Our BICS requires neither an external voltage …

Developing A Methodology To Detect Partial Failures For Dynamic Systems, Anwar A. Al-Jowder

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to develop a decision support system that can assist in detecting partial failures in dynamic systems such as Fire Control System Tracking Radar (TR) onboard Naval Ships. Partial failures do not necessarily shut down the system immediately but cause degradation of operational performance. Previous work has shown that experts in the field of failure detection, test point insertion and Built-In-Test Equipment (BITE) can provide useful input in detecting partial failures. Partial failures affect operational system performance and support costs, which can be significant. Often, however, partial failure detection consists of the estimations and opinions …

Tcm Decoding Using Neural Networks, Edit J. Kaminsky, Nikhil Deshpande

Electrical Engineering Faculty Publications

This paper presents a neural decoder for trellis coded modulation (TCM) schemes. Decoding is performed with Radial Basis Function Networks and Multi-Layer Perceptrons. The neural decoder effectively implements an adaptive Viterbi algorithm for TCM which learns communication channel imperfections. The implementation and performance of the neural decoder for trellis encoded 16-QAM with amplitude imbalance are analyzed.

Processor Microarchitecture For Implementation Of Ephemeral State Processing Within Network Routers, Muthulakshmi Muthukumarasamy

Theses and Dissertations--Electrical and Computer Engineering

The evolving concept of Ephemeral State Processing (ESP) is overviewed. ESP allows development of new scalable end-to-end network user services. An evolving macro-level language is being developed to support ESP at the network node level. Three approaches for implementing ESP services at network routers can be considered. One approach is to use the existing processing capability within commercially available network routers. Another approach is to add a small scale existing ASIC based general-purpose processor to an existing network router. This thesis research concentrates on a third approach of developing a special-purpose programmable Ephemeral State Processor (ESPR) Instruction Set Architecture (ISA) …

A Shape-Based Approach To Change Detection Of Lakes Using Time Series Remote Sensing Images, Jiang Li, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

Shape analysis has not been considered in remote sensing as extensively as in other pattern recognition applications. However, shapes such as those of geometric patterns in agriculture and irregular boundaries of lakes can be extracted from the remotely sensed imagery even at relatively coarse spatial resolutions. This paper presents a procedure for efficiently retrieving and representing shapes of interesting features in remotely sensed imagery using supervised classification, object recognition, parametric contour tracing, and proposed piecewise linear polygonal approximation techniques. In addition, shape similarity can be measured by means of a computationally efficient metric. The study was conducted on a time …

United States Patent Application Publication: Divide And Conquer System And Method Of Dna Sequence Assembly, Khalid Sayood, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

The present invention provides a new algorithm for assembling fragments from a long DNA sequence. The algorithm of the invention Solves simultaneously fragment assembly-related problems. Such as the fragment orientation, overlap and layout phases. This is achieved by clustering fragments with respect to their Average Mutual Information (AMI) profiles using the k-means algorithm.

Performance Evaluation Of Sip Based Services In Umts, Maria Isabel Pous Fenollar

Theses

With ever increasing penetration of IP technologies and the tremendous growth in wireless data traffic, the wireless industry is evolving the mobile core networks towards IP technology. The 3rd Generation Partnership Project (3GPP) is specifying an IP Multimedia Core Network Sub-System (IMS) in UMTS Release 5 and Release 6, which is adjunct to the UMTS GPRS core network. This IP-based network will allow mobile operators to provide commonly used Internet applications to wireless user. The UMTS IMS uses the Internet Engineering Task Force (IETF) defined text based Session Initiation Protocol (SIP), to control a wide range of anticipated IP-based services …

Dynamically Biased Radio Frequency Power Amplifier, Tom Twomey

Theses

With the current trend in mobile communications towards more complex modulation schemes to enhance spectral efficiency, the design of RF power amplifiers is the subject of considerable interest and research. The newer more spectrally efficient modulation schemes require a much higher level of linearity due to the non-constant level of their signal envelope. A variable envelope signal would in non-linear amplifiers lead to unacceptable levels of distortion. Linear amplifiers solve this problem at the cost of significant loss of efficiency. With the evolution towards more spectrally efficient modulation schemes, the trade off between linearity and power efficiency has become more …

Modeling, Fabrication, And Optimization Of Niobium Cavities: Final Phase, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. This is the third and final phase of the study.

The first phase has resulted in improving the basic understanding of multipacting and the process of chemical etching. The second phase has resulted in an experimental setup …

Modeling, Fabrication, And Optimization Of Niobium Cavities, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

One of the key technologies for the deployment of accelerator driven transmutation systems is the accelerator itself. To increase the efficiency of the high-power accelerators needed to support the transmutation mission, the national and international accelerator teams have proposed using elliptical superconducting niobium cavities. This project is tasked with examining the impacts of the design and fabrication technologies for these elliptical niobium cavities on their performance. Niobium was selected primarily due to its behavior at low temperatures.

One of the major sources of energy loss from a superconducting accelerator cavity is a process known as multiple impacting (or “multipacting”) of …

Frequency-Hopped Multiple-Access Communications With Noncoherent M-Ary Ofdm-Ask, A. Al-Dweik, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

A noncoherent, bandwidth-efficient modulation scheme is proposed for frequency-hopping multiple-access (FH-MA) networks. The proposed scheme is a combination of noncoherent M-ary amplitude-shift keying (NMASK) and orthogonal frequency-division multiplexing (OFDM). Using this scheme minimizes the required data bandwidth. The number of frequency slots available to the users increases significantly for a fixed spread-spectrum bandwidth (BW_SS). The effect of the multiple-access interference is reduced. Simple and accurate bit error rate expressions have been derived for FH-OFDM-MASK in additive white Gaussian noise channels and for FH-OFDM-ASK in Rayleigh fading channels.

Formation Of Porous Silicon Through The Nanosized Pores Of An Anodized Alumina Template, Biswajit Das, S. P. Mcginnis

Electrical & Computer Engineering Faculty Research

This letter demonstrates the ability to fabricate porous silicon through the nanoscale pores of an anodized alumina template formed on a silicon substrate. The alumina template acts as a protective coating on the porous silicon surface increasing its mechanical integrity, thus eliminating the need for delicate handling that is usually required for this material system. The optical properties of the porous silicon formed through the template show characteristics similar to that of normally formed porous silicon. In addition, the porous siliconoptical properties show very little degradation with time; the alumina coating is believed to contribute to this improved stability. The …

Network Traffic Properties Of Bimodal Multicast Protocol, Öznur Özkasap, Mi̇ne Çağlar

Turkish Journal of Electrical Engineering and Computer Sciences

The popularity of large-scale distributed applications, such as videoconferencing, multimedia dissemination, electronic stock exchange and distributed cooperative work, has grown with the availability of high-speed networks and the expansion of the Internet. The key property of this type of applications is the need to distribute data among multiple participants together with an application-specific quality of service needs. This fact makes scalable multicast protocols an essential underlying communication structure. Although there exist several studies investigating the traffic characteristics of unicast communication, multicast traffic has not been examined extensively in previous studies. It is well known that the aggregate traffic properties of …

Zero-Crossing Based Demodulation Of Minimum Shift Keying, Mi̇ne Kalkan, Feza Keresteci̇oğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Minimum shift keying (MSK) modulation has features such as constant envelope, compact spectrum and good error performance, which are all desirable in many digital applications including mobile radio. Numerous receiver structures to demodulate MSK have been suggested, such as correlation receivers, differential detectors and frequency discriminators. MSK is a form of biphase keying and can be detected by a zero-crossing based phase demodulator which gives near optimum performance. In this paper, the bit error performance of a zero-crossing based coherent MSK demodulator is theoretically investigated and a closed-form expression for the bit error rate is derived. The results indicate that …

Music, Cbf And Differential Algebraic Constant Modulus Algorithms For Direction Of Arrival Estimation In Passive Coherent Locators, Ahmet Özçeti̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In passive coherent locators (PCL) systems, noise and the precision of direction of arrival (DOA) estimation are key issues. This paper addresses the implementation of high-resolution DOA estimation methods, in particular the multiple signal classification (MUSIC) algorithm, the conventional beam forming (CBF) algorithm, and the algebraic constant modulus algorithm (ACMA). The goal is to compare the ACMA to the MUSIC and CBF algorithms for application to PCL. The results and analysis presented here support the use of constant modulus information, where available, as an important addition to DOA estimation. The ACMA offers many simple solutions to noise and separation related …

Biology Goes Digital: An Array Of 5,700 Spartan Fpgas Brings The Biowall To "Life", Christof Teuscher, Gianluca Tempesti

Electrical and Computer Engineering Faculty Publications and Presentations

A unique, scientific research instrument and art piece, the BioWall models bio-inspired electronic tissues capable of evolution, selfrepair, self-replication – and learning. Much pure and applied scientific research has focused on replicating biological functions in digital hardware. Here, at the Logic Systems Laboratory of the Swiss Federal Institute of Technology in Lausanne (EPFL), we have utilized 5,700 Xilinx Spartan™ FPGAs, in multiple configurations, to build bio-inspired computing machines that exploit three essential biological models: • Phylogenesis – the history of the evolution of the species • Ontogenesis – the development of an individual as directed by his genetic code • …

Quality Challenges In E-Commerce Websites, Ronan Fitzpatrick

Conference papers

No abstract provided.

Comparison Of Particle Swarm Optimization And Backpropagation As Training Algorithms For Neural Networks, Ganesh K. Venayagamoorthy, Venu Gopal Gudise

Electrical and Computer Engineering Faculty Research & Creative Works

Particle swarm optimization (PSO) motivated by the social behavior of organisms, is a step up to existing evolutionary algorithms for optimization of continuous nonlinear functions. Backpropagation (BP) is generally used for neural network training. Choosing a proper algorithm for training a neural network is very important. In this paper, a comparative study is made on the computational requirements of the PSO and BP as training algorithms for neural networks. Results are presented for a feedforward neural network learning a nonlinear function and these results show that the feedforward neural network weights converge faster with the PSO than with the BP …

Control Of Cascaded Multi-Level Inverters, Keith Corzine, Fang Zheng Peng, J. Wang, M. W. Wielebski

Electrical and Computer Engineering Faculty Research & Creative Works

A new type of multi-level inverter is introduced which is created by cascading two three-phase three-level inverters using the load connection. This new inverter can operate as a nine-level inverter and naturally splits the power conversion into a higher voltage lower-frequency inverter and a lower-voltage higher frequency inverter. This type of system presents particular advantages to naval ship propulsion systems which rely on high power quality, survivable drives. New control methods are described involving both joint and separate control of the individual three-level inverters. Simulation results demonstrate the effectiveness of both controls. A laboratory set-up at the Naval Surface Warfare …

Voltage Balancing Control Of Diode-Clamped Multilevel Rectifier/Inverter Systems, Zhiguo Pan, Keith Corzine, V. R. Stefanovic, J. M. Leuthen, Fang Zheng Peng

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a new voltage balancing control for the diode-clamped multilevel rectifier/inverter system. A complete analysis of the voltage balance theory for a 5-level back-to-back system is given. The analysis is based on fundamental frequency switching control and then extended to pulse-width modulation. The method involves obtaining optimal switching angles; a process which is described in detail in this paper. The proposed control strategy regulates the DC bus voltage, balances the capacitors, and decreases the harmonic components of the voltage and current. Simulation and experimental results demonstrate the validity of the optimizing method and control theory.

Adaptive Neural Network Based Power System Stabilizer Design, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Power system stabilizers (PSS) are used to generate supplementary control signals for the excitation system in order to damp the low frequency power system oscillations. To overcome the drawbacks of conventional PSS (CPSS), numerous techniques have been proposed in the literature. Based on the analysis of existing techniques, this paper presents an indirect adaptive neural network based power system stabilizer (IDNC) design. The proposed IDNC consists of a neuro-controller, which is used to generate a supplementary control signal to the excitation system, and a neuro-identifier, which is used to model the dynamics of the power system and to adapt the …

An Industrial Food Processing Plant Automation Using A Hybrid Of Pi And Fuzzy Logic Control, Ganesh K. Venayagamoorthy, D. Naidoo, P. Govender

Electrical and Computer Engineering Faculty Research & Creative Works

An industrial food processing plant consisting of nonlinear dynamics requires pressure and temperature controllers to be nonlinear. In this paper, nonlinear controllers are designed using fuzzy logic to augment the conventional pressure and temperature PI controllers for an industrial food processing plant. Simulation results are presented to show improvement in the plant response with the hybrid controllers.

Adaptive-Critic-Based Optimal Neurocontrol For Synchronous Generators In A 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 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 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 in turn compared …

Speaking And Writing Proficiency Of International Graduate Students In Elective, Mentoring Environments, Steve Eugene Watkins, Randy Green

Electrical and Computer Engineering Faculty Research & Creative Works

Technical communication skills are critical for non-native speakers who must study and interact in English-only professional settings. Often, formal instruction to pass admission thresholds and other minimum requirements are not sufficient to attain proficiency. This paper describes elective, long-term programs that provide systematic opportunities for both speaking and writing development. These programs are tailored to international students through the key features of individualized activities, applied task-oriented practice, and social interaction. The elective programs attract and retain participants with interest and need for high-level language proficiency. Program evaluations show that participating graduate students give primary credit for their growing fluency to …

Optimization Of An Automotive Generator Using Evolutionary Programming, A. Koenig, J. Williams, Steven Pekarek

Electrical and Computer Engineering Faculty Research & Creative Works

One of the primary design requirements of automotive generation systems is maximizing power density subject to the constraint of minimizing overall system cost. However, with progress made in reduction of automotive drive train noise, the torque ripple of the generator has been found to be a dominant noise source under idle conditions at high electrical load. Thus, an added design constraint is the minimization of torque ripple produced by the machine. in order to meet these objectives, numerical tools have been developed to automate the design process. a primary tool is an evolutionary algorithm that has been integrated within a …

Welcome To The Special Issue: The Best Of The Best, Donald C. Wunsch, Mike Hasselmo, De Liang Wang, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Adaptive Critic Neural Network-Based Controller For Nonlinear Systems With Input Constraints, Pingan He, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel adaptive critic-Based multilayer neural network (NN) controller in discrete-time is designed to deliver a desired tracking performance for a class of nonlinear systems in the presence of magnitude constraints on the input. Reinforcement learning scheme in discrete time is proposed for the NN controller, where the action generating NN learning is performed based on a certain performance measure, which is supplied from a critic. using the Lyapunov approach and with a novel weight update, the uniform ultimately boundedness (UUB) of the closed loop tracking error and weight estimates are shown. the adaptive critic NN does not require an …

Coolant Pump Drive: An Application For Switched Reluctance Machines, Chris S. Edrington, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

Current vehicle architectures utilize belt driven components such as the coolant pump, air-conditioner, power steering pump etc. However, the trend toward more electric vehicles requires novel applications of machines to replace these inefficient mechanical components. It is essential that electrical machines used in automotive applications be compatible with the corresponding mechanical and electrical terminals. Furthermore, replacement of belt driven components with electrical drives, should be performed as efficient and cost effective as possible. Switched Reluctance Machines (SRM) are both cost effective and very robust to the effects of temperature variation. They also offer a very wide speed range and an …

Enhancement Of Output Electric Power In Switched Reluctance Generators, S. Dixon, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a new switching strategy to increase overall productivity for a switched reluctance generator (SRG). This paper presents the idea of using an intermediate freewheeling mode to boost the magnetizing current without taking additional energy from the DC link. Once the optimal motional back-EMF is established, then both switches will be turned off. Although during the freewheeling process no electricity is generated, by proper timing of each region an overall enhancement in productivity of the SRG is achieved. to demonstrate the practicality of the proposed technique, simulation results are provided. These simulations take into account the switching losses …