Engineering Commons^™

New Infratechnologies In The Deregulated Power Sector, Jordan Shikoski, Vladimir Katic, Risto Rechkoski

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses new infratechnologies in the deregulated power sector. Most measurement and standardization techniques can be viewed as infratechnology. Infratechnologies are technical tools, including the measurement of data, test methods, and practices and technique. Standardization requirements are related to the measurement requirement. Although the system operation and market transactions concern many import aspects, they are insupportable and often complementary. This distinction between the technical and market information is important because the characteristics of information needs and the impact on economic efficiency and clean power are generally different. The present paper focuses on infratechnologies that can potentially increase the benefits …

A Digitally Controlled Drive System For Travelling-Wave Ultrasonic Motor, Güngör Bal

Turkish Journal of Electrical Engineering and Computer Sciences

A digitally controlled drive system was implemented in this study to control the speed and direction of a travelling-wave ultrasonic motor. The drive system, based on a 2-phase voltage-fed high-frequency serial-resonant inverter, uses the mechanical resonant frequency of an ultrasonic motor. A TMS320F243 digital signal processor was used to control an ultrasonic motor drive system. The speed control of the ultrasonic motor was achieved with a driving frequency in the 41.3-43.3 kHz frequency range. The feasible evaluations of the proposed drive and control system were tested by experiments. Experimental results demonstrated that the proposed drive and control system is flexible …

Initiatory Electrons In Compressed Gases In Positive Polarity, Mohammed Messaad, Mustapha Tioursi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with the nature of seed electron sources in compressed N_2 for positive polarity. We present an experimental procedure that provides evidence of the fact that collisional detachment from negative ions plays the most important role in the supply of seed electrons. Conditioning phenomena in compressed SF_6, N_2 and air have been simulated under positive lightning impulses for point-plane geometry.

A New Simulator For Hvdc/Ac Systems-Part I, Baktiar Zangeneh, Abbas Shoulaie

Turkish Journal of Electrical Engineering and Computer Sciences

A simulator with optimal step time (SOST) has been designed to investigate Large HVdc/ac systems. The adequacy and robustness of the simulator will be demonstrated by showing some important applications relevant to operation, operational planning and medium-term planing. Some of the features of our SOST simulator are optimal step time algorithm, interpolation, chatter removal, MATLAB interface, unlimited size of ac system, and Farsi command that help model complex power electronic circuits, provide fast and accurate results. On account of its reduced calculation effort and deterministic execution time, optimal-step simulation is a prerequisite for real-time performance. However, when simulating electromagnetic-transients behavior, …

A New Simulator For Hvdc/Ac Systems-Part Ii, Baktiar Zangeneh, Abbas Shoulaie

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a performance comparison (the focus of numerical simulation) of traditional simulation (TCS,TSE) with an optimal step time simulator (SOST) for large HVdc systems.In SOST, a Detailed simulation of HVdc converter behavior has been modified to include the automatic selection of optimal integration steps, frequency-dependent effects of an ac system, ac system phase and magnitude dynamics of voltage (particularly weak ac systems), control assessment and temporary over-voltage consequences. SOST, via graphical interfaces,provides fast and accurate information of electromechanical and the electromagnetic-transients behavior of a large HVdc/HVac system.

Motion Planning Using Potential Fields, Randal W. Beard, Timothy W. Mclain

Faculty Publications

The objective of these notes is to describe a reactive approach to motion planning for mobile robots. In a reactive approach, trajectories are not planned explicitly. Rather, robot interactions are defined explicitly and the robot motion is said to "emerge." The drawback of reactive methods is that it is sometimes difficult to get the robot to do exactly what you want. The reactive approach that will be described in these notes is called the "virtual fields" method and is commonly used in robotics.

Measurement Of Mode Patterns In A High-Power Microwave Cavity, Sergey Kharkovsky, U. C. Hasar

Electrical and Computer Engineering Faculty Research & Creative Works

A wet thermal paper method for measuring of mode patterns and heat distributions in a high-power microwave multimode cavity is developed. The exposure time of the paper is evaluated. It is shown that this method allows measuring and recording mode patterns in the loaded and unloaded cavity, and the heat distribution inside the cavity with a load movement. The mode patterns and heat distributions along horizontal and vertical planes of the cavity are presented. Possible applications of the method in medicine and biology are discussed, and a calibration protocol of a microwave oven for microwave radiation exposure on cell cultures …

Adaptive Baseband Predistortion For Rf Power Amplifier Linearization., Laura Faus-Ferrer

Theses

In order to make use of spectrally efficient linear modulation methods for mobile communications, it is necessary to linearise the underlying RF power amplifier (PA). A number of techniques for linearizing a PA have been studied, focusing on the Adaptive Baseband Predistortion. The work is centred on the research concentrates on the analysis of different algorithms, their simulation using MatLab, and implementation of a predistorter as a subsystem of a prototype Cartesian based transmitter.

The thesis describes the typical architecture of a transceiver with an emphasis on the nonlinear analysis. Cavers’ algorithm has been examined in terms of its computational …

Hot Carrier Reliability Of Lateral Dmos Transistors In Power Process Applications, Vicky O'Donovan

Theses

The purpose of this study is to investigate and validate the mechanism of hot carrier degradation of the LDMOS device. The LDMOS device is a new technology to Analog Devices, and a relatively new topic to the semiconductor industry, evident from the limited published research in the field. A prerequisite for device release on a product in the market place, is comprehensive hot carrier reliability testing, as hot carrier degradation has evolved as one of the foremost concerns in submicron devices. Both the high voltage and the structural difference of the LDMOS device, from standard MOSFET device, pose a hot …

A Unique Fault-Tolerant Design For Flying Capacitor Multilevel Inverters, X. Kou, Keith Corzine, Yakov L. Familiant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a unique design for flying capacitor type multilevel inverters with fault-tolerant features. When a single-switch fault per phase occurs, the new design can still provide the same number of converting levels by shorting the fault power semiconductors and reconfiguring the gate controls. The most attractive point of the proposed design is that it can undertake the single-switch fault per phase without scarifying power converting quality. This paper also discusses the capacitor balancing approach under fault-conditions, which is an essential part of controlling flying capacitor type multilevel inverters. Suggested fault diagnosing methods are also discussed in this paper. …

Antenna-Coupled Infrared Focal Plane Array, Francisco Javier Gonzalez

Retrospective Theses and Dissertations

In this dissertation a new type of infrared focal plan array (IR FPA) was investigated, consisting of antenna-coupled microbolometer fabricated using electron-beam lithography. Four different antenna designs were experimentally demonstrated at 10-micron wavelength: dipole, bowtie, square-spiral, and log-periodic. The main differences between these antenna types were their bandwidth, collection area, angular reception pattern, and polarization. To provide pixel collection areas commensurate with typical IR FPA requirements, two configurations were investigated: a two-dimensional serpentine interconnection of individual IR antennas, and a Fresnel-zone-plate (FZP) coupled to a single-element antenna. Optimum spacing conditions for the two-dimensional interconnect were developed. Increased sensitivity was demonstrated …

Design Of A Tem-Cell With Increased Usable Test Area, Kresimir Malaric, Juraj Bartolic

Turkish Journal of Electrical Engineering and Computer Sciences

Transversal electromagnetic mode cells (TEM-cells) are used for electromagnetic compatibility measurements (emission and immunity), and for biomedical applications. Over the years, higher and higher frequencies are being used, which demands smaller transmission structures in order to obtain the homogeneous field distribution due to resonance. Such resonance destroys the TEM field, introducing higher order modes. The goal was to design the TEM-cell for GSM frequencies that will have a larger area with a homogeneous field used for testing, while still obtaining the characteristic impedance. Commercial TEM-cells used for frequencies of 900 MHz have only 2 cm in height available for testing, …

New Modified Smith Predictor Designs, Pauline Sourdille, Aidan O'Dwyer

Conference papers

By combining several existing modified Smith predictor structures, presented in a literature review, a generalised form of the Smith predictor is proposed. From this structure, excellent servo and regulator responses can be obtained by specifying three controller dynamic elements. Two new modified Smith predictor structures are presented with their associated tuning rules. The results of the simulations indicate that the two new designs give better overall responses than the original Smith predictor.

Comparison Of Process Identification Techniques In The Time And Frequency Domains, Tony Kealy, Aidan O'Dwyer

Conference papers

This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].

Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer

Conference papers

In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the ISE performance index value for a FOPDT process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the use of tuning rules. The second part of this paper …

Speech-Adaptive Time-Scale Modification For Computer Assisted Language Learning, Olivia Donnellan, Elmar Jung, Eugene Coyle

Conference papers

In traditional foreign language learning programmes students are offered a tutor model characterised by slow, deliberate speech. This is insufficient to prepare them to cope with native, colloquial speech. By applying a timescale modification (TSM) algorithm to natural-speed, native speech, students have access to a more desirable, natural speech corpus which permits them to practise essential listening skills in a more focussed manner. This paper presents a method which allows slowing down speech without compromising the quality, pitch or naturalness of the slowed speech by applying different scaling factors to different types of speech segments. The new method is compared …

Design For Signal Integrity In High Frequency, High Density Circuit Boards, Juan Manuel Talavera Martinez

Theses

The electronics market is continually seeking fast and small high performance products. The clock frequency in computer systems is often above 2GHz and new generations of laptops have considerably reduced in size. These features make printed circuit board (PCB) design more difficult than in the past.

This thesis is an investigation of the current design of high speed PCB. The complexity of this type of circuit makes the designer needs an extensive knowledge of the techniques used to generate a reliable signalling, in other words, signal integrity. To achieve this objective, the design community has to overcome several problem related …

Instantaneously Trained Neural Networks With Complex Inputs, Pritam Rajagopal

LSU Master's Theses

Neural network architectures that can handle complex inputs, such as backpropagation networks, perceptrons or generalized Hopfield networks, require a large amount of time and resources for the training process. This thesis adapts the time-efficient corner classification approach to train feedforward neural networks to handle complex inputs using prescriptive learning, where the network weights are assigned simply upon examining the inputs. At first a straightforward generalization of the CC4 corner classification algorithm is presented to highlight issues in training complex neural networks. This algorithm performs poorly in a pattern classification experiment and for it to perform well some inputs have to …

Blind Fault Detection Using Spectral Signatures, Pallavi Chethan

LSU Master's Theses

This work studies a blind fault detection method, which only analyses a system's output signal for any change in the characteristics from pre-fault to post-fault to identify the occurrence of faults. In our case the fault considered to develop the procedure is change in time constant of an aircraft's aileron-actuator system and its simplified version - a position servo system. The method is studied as an alternative to conventional fault detection and identification methods. The output signal is passed through a filter bank to enhance the effect of a fault. The Short time Fourier transform is performed on the enhanced …

Transmission Of Electromagnetic Power Through A Biological Medium, Ripan Das

LSU Master's Theses

Primary goal of this work is to study transmission of EM power through a multilayered biological medium. For a particular case study, EM power transmission from an external transmitter to a coupled receiver implanted inside a biological medium simulating a human body is studied to find solutions for factors such as optimum transmission frequency and excitation current. Different aspects of interaction of EM waves with biological bodies and tissues are discussed. Two major factors that may affect transmission of EM power through a biological body are absorption and reflection of EM waves. A simulation in which exact Maxwell's equations are …

Transmission Property And Evanescent Wave Absorption Of Cladded Multimode Fiber Tapers, Shangping Guo, Sacharia Albin

Electrical & Computer Engineering Faculty Publications

Cladded multimode fiber optic tapers are proposed as chemical sensors using evanescent wave absorption. There is no need to strip the cladding; therefore, fabrication is easy and the taper is mechanically stronger than the taper without cladding. The transmission property and evanescent wave absorption are modeled using ray theory and wave theory, respectively. Effects of some parameters on the absorption sensitivity are analyzed numerically. Due to the presence of the cladding, the taper core is not in direct contact with the external medium, leading to some significant differences from the uncladded one, especially when the index of the external medium …

Novel High Frequency Silicon Carbide Static Induction Transistor-Based Test-Bed For The Acquisition Of Sic Power Device Reverse Recovery Characteristics, Kevin M. Speer, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth, Kraig J. Olejniczak

Journal of the Arkansas Academy of Science

A test system is presented that utilizes a high-frequency Silicon Carbide (SiC) Static Induction Transistor (SIT) in place of the traditional MOSFET to test reverse recovery characteristics for the new class of SiC power diodes. An easily implementable drive circuit is presented that can drive the high-frequency SIT. The SiC SIT is also compared to a commonly used Si MOSFET in the test circuit application.

Parameter Extraction Software For Compact Diode Model, Maruf Hossain, Edgar Cilio, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth

Journal of the Arkansas Academy of Science

No abstract provided.

Testing And Modeling Electrical Characteristics Of Novel Silicon Carbide (Sic) Static Induction Transistors (Sits), Avinash S. Kashyap, Sharmila D. Mangan Lal, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth

Journal of the Arkansas Academy of Science

No abstract provided.

Plasma Interaction With Microbes, M. Laroussi, D. A. Mendis, M. Rosenberg

Electrical & Computer Engineering Faculty Publications

The germicidal effects of a non-equilibrium atmospheric pressure plasma generated by a novel resistive barrier discharge on representatives of the two classes of bacteria (Gram-negative and Gram-positive) are discussed. The plasma exposure, while being lethal to both bacterial classes, also produced gross structural damage in the Gram-negative E. coli while none was observed in the more structurally robust Gram-positive Bacillus subtilis. An electrophysical process involving the role of the electrostatic tension on a charged body in a plasma is invoked to explain both observations. Since the efficacy of this electrophysical process depends not only on the tensile strength of …

A Simple Quantum Mechanical Treatment Of Scattering In Nanoscale Transistors, Rajesh Venugopal, Magnus Paulsson, Sebastien Goasguen, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

We present a computationally efficient, two-dimensional quantum mechanical simulation scheme for modeling dissipative electron transport in thin body, fully depleted, n-channel, silicon-on-insulator transistors. The simulation scheme, which solves the nonequilibrium Green’s function equations self consistently with Poisson’s equation, treats the effect of scattering using a simple approximation inspired by the “Büttiker probes,” often used in mesoscopic physics. It is based on an expansion of the active device Hamiltonian in decoupled mode space. Simulation results are used to highlight quantum effects, discuss the physics of scattering and to relate the quantum mechanical quantities used in our model to experimentally measured …

Quantum Mechanical Analysis Of Channel Access Geometry And Series Resistance In Nanoscale Transistors, R. Venugopal, S. Goasguen, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

We apply a two-dimensional quantum mechanical simulation scheme to study the effect of channel access geometries on device performance. This simulation scheme solves the nonequilibrium Green’s function equations self-consistently with Poisson’s equation and treats the effect of scattering using a simple approximation inspired by Büttiker. It is based on an expansion of the device Hamiltonian in coupled mode space. Simulation results are used to highlight quantum effects and discuss the importance of scattering when examining the transport properties of nanoscale transistors with differing channel access geometries. Additionally, an efficient domain decomposition scheme for evaluating the performance of nanoscale transistors is …

Multiple Model Control With Intelligent Switching To Ensure Robustness To Process Variations., Peter Cunningham

Theses

One of the most popular approaches for dealing with process that undergo large variations with time, of late, is the multiple model approach. This method has considerable intuitive appeal and has received widespread dissemination in academia. Numerous successful simulations have been reported although few real-time results have been published. The principal contribution of this thesis is the application of the multiple model control scheme in real-time.

A number of practical concepts that enable the use of multiple model control in real-time are discussed. Many of these issues arose when the multiple model control scheme was applied to a laboratory scale …

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 …