Engineering Commons^™

Plasma Treatment Of Bulk Nb Surface In The Ar/Cl2 Discharge, M. Rašković, L. Vuskovic, S. Popovic, A.-M. Valente-Feliciano, L. Phillips

Physics Faculty Publications

The preparation of the cavity walls has been one of the major challenges in the superconducting radio-frequency (SRF) accelerator technology. Therefore, constant research and development effort is devoted to develop surface preparation processes that will improve roughness and lower the level of impurities, like hydrogen or oxygen, embedded in bulk Nb, having in the same time reasonable etching rates. Plasma based surface modification provides an excellent opportunity to achieve these goals. We present Ar/Cl₂ discharge treatment of bulk Nb where we achieved etching rates comparable to the rates obtained with the electropolishing method without introducing impurities in Nb. The …

An Evaluation Of Supercritical Drying And Peg/Freeze Drying Of Waterlogged Archaeological Wood, Eric Schindelholz, Robert Blanchette, Desmond C. Cook, Michael Drews, Steve Hand, Benjamin Held, Joel Jurgens, Betty Seifert

Physics Faculty Publications

This study was undertaken to evaluate the physical effects of drying waterlogged archaeological wood using supercritical carbon dioxide as compared to air drying and the popular polyethylene glycol (PEG)/freeze drying method. Previous studies have shown supercritical drying to be a potentially advantageous alternative to current methods of drying waterlogged wood through reduced processing time, minimal shrinkage, and increased success for reversibility. Samples in the form of blocks and planks of a few centimeters in size were prepared from two archaeological waterlogged wood sources and grouped into three treatment sets: one for air drying, one for PEG/freeze drying, and the other …

Technology And Competence Alignment To The Roadmap, Mihir M. Gokhale, Donald D. Myers

Engineering Management and Systems Engineering Faculty Research & Creative Works

Roadmaps serve as a useful graphical tool to integrate strategic objectives, technology-assessment, technology-road mapping and product road mapping against an axis of time. Much research has been done related to linking specific technologies with the product roadmap. It is equally important to understand how the sourcing of this technology can be done. This leads to the discussion of competence development to meet the technology gap. the paper describes the alignment of this technology and competence with the overall roadmap. © 2008 IEEE.

Adaptive Neural Network Based Stabilizing Controller Design For Single Machine Infinite Bus Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani, Mariesa Crow

Engineering Management and Systems Engineering Faculty Research & Creative Works

Power system stabilizers are widely used to generate supplementary control signals for the excitation system in order to damp out the low frequency oscillations. In power system control literature, the performances of the proposed controllers were mostly demonstrated using simulation results without any rigorous stability analysis. This paper proposes a stabilizing neural network (NN) controller based on a sixth order single machine infinite bus power system model. The NN is used to approximate the complex nonlinear dynamics of power system. Unlike the other indirect adaptive NN control schemes, there is no offline training process and the NN can be directly …

An Evaluation Of Mahalanobis-Taguchi System And Neural Network For Multivariate Pattern Recognition, Jungeui Hong, Rajesh Jugulum, Kioumars Paryani, K. M. Ragsdell, Genichi Taguchi, Elizabeth A. Cudney

Engineering Management and Systems Engineering Faculty Research & Creative Works

The Mahalanobis-Taguchi System is a diagnosis and predictive method for analyzing patterns in multivariate cases. The goal of this study is to compare the ability of the Mahalanobis- Taguchi System and a neural-network to discriminate using small data sets. We examine the discriminant ability as a function of data set size using an application area where reliable data is publicly available. The study uses the Wisconsin Breast Cancer study with nine attributes and one class.

Effective Use Of Process Capability Indices For Supplier Management, Elizabeth A. Cudney, David Drain

Engineering Management and Systems Engineering Faculty Research & Creative Works

Process capability indices were originally invented to enable an organization to make economically sound decisions for process management. Process capability is a comparison of the voice of the process with the voice of the customer. Current practice is to use Cp and Cpk regardless of the validity of the underlying assumptions necessary for their use. Even if all necessary assumptions are satisfied, important problems can be missed if these indices are the sole process evaluation examined. Customer-supplier axioms are introduced to motivate more useful process evaluations and foster long-term harmonious relationships. This paper explores the alternative capability indices Cpm, Cpmk, …

Increasing Energy Efficiency Through Improvements In Ladle Materials And Practices, Kent D. Peaslee, Semen Naumovich Lekakh, Jeffrey D. Smith, Mangesh Vibhandik

Materials Science and Engineering Faculty Research & Creative Works

Steel foundry ladle practices play an important role in total energy efficiency of melting as well as influence casting quality. Extensive heat losses in the ladle could be associated with excessive superheating of the melt before tap which increases energy consumption, promotes oxidation of the melt and increases refractory consumption. A high cooling rate of the liquid metal in the ladle could also cause casting quality instability. The overall ladle heat balance and components of heat losses were analyzed using FLUENT and FACTSAGE software and validated with experimental data from both the UMR foundry and industrial foundries. The purpose of …

Exact And Heuristic Algorithms For The Job Shop Scheduling Problem With Earliness And Tardiness Over A Common Due Date, Leonardo Bedoya-Valencia

Engineering Management & Systems Engineering Theses & Dissertations

Scheduling has turned out to be a fundamental activity for both production and service organizations. As competitive markets emerge, Just-In-Time (JIT) production has obtained more importance as a way of rapidly responding to continuously changing market forces. Due to their realistic assumptions, job shop production environments have gained much research effort among scheduling researchers. This research develops exact and heuristic methods and algorithms to solve the job shop scheduling problem when the objective is to minimize both earliness and tardiness costs over a common due date. The objective function of minimizing earliness and tardiness costs captures the essence of the …

Noise-Robust Automatic Speech Recognition Using A Predictive Echo State Network, Mark D. Skowronski, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Artificial neural networks have been shown to perform well in automatic speech recognition (ASR) tasks, although their complexity and excessive computational costs have limited their use. Recently, a recurrent neural network with simplified training, the echo state network (ESN), was introduced by Jaeger and shown to outperform conventional methods in time series prediction experiments. We created the predictive ESN classifier by combining the ESN with a state machine framework. In small-vocabulary ASR experiments, we compared the noise-robust performance of the predictive ESN classifier with a hidden Markov model (HMM) as a function of model size and signal-to-noise ratio (SNR). The …

A Precompensation Algorithm For Pwm-Based Digital Audio Amplifiers For Portable Applications, Xiaoxiang Gong, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

A novel precompensation algorithm for a Pulse Width Modulation (PWM)-based digital audio amplifier has been developed for portable applications. The Straight-Line Segment PWM (SLSPWM) algorithm results in both low-power and low-complexity devices. The division-free version of this algorithm modifies the algorithm by removing the division using a polynomial approximation. Both SLSPWM and Division-Free SLSPWM feature 16-bit quality performance with fewer calculations compared with previous works. © 2007 IEEE.

Assuring A Complex Safety-Critical Systems Of Systems, Steven C. Beland, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a broad assurance approach for developing a complex, safety-critical System of Systems (SoS) in order to supplement some guidance that exists in the industry today. Drawing on these varied guidance sources for the assurance of specific technologies and others for developing a modern complex system (or SoS), this paper combines these to present objective-Based criteria to assure a complex safety-critical SoS. This guidance can enable a person or team to write a complete objective-Based development assurance plan for a complex safety-critical SoS and create completion criteria to use for recognizing when it is done. Copyright © 2007 …

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

This project focuses on the chemical bonding and interface formation of metal fission products with the coating materials used in tri-isotropic (TRISO) fuel particles for gas-cooled reactors. By combining surface- and bulk-sensitive spectroscopic methods, intermediate chemical phases at the interface, intermixing/ diffusion behavior, and the electronic interface structure as a function of material (metal and coating materials) and temperature are examined.

In the past year, emphasis was placed on a detailed analysis and description of the Cs/SiC interface formation process.

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct accelerator driven experiments, which will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared to calculations …

Asymptotic Stability Of Nonholonomic Mobile Robot Formations Using Multilayer Neural Networks, Jagannathan Sarangapani, Travis Alan Dierks

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a combined kinematic/torque control law is developed for leader-follower based formation control using backstepping in order to accommodate the dynamics of the robots and the formation in contrast with kinematic-based formation controllers that are widely reported in the literature. A multilayer neural network (NN) is introduced along with robust integral of the sign of the error (RISE) feedback to approximate the dynamics of the follower as well as its leader using online weight tuning. It is shown using Lyapunov theory that the errors for the entire formation are asymptotically stable and the NN weights are bounded as …

Method Of Metallurgically Bonding Articles And Article Therefor, Hai-Lung Tsai, P.-C. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An article suitable for metallurgical bonding having a first part having a lower surface, and a second part having an upper surface is disclosed. The lower surface of the first part is disposed at the upper surface of the second part to provide for a faying surface thereat. The faying surface has a plurality of channels having a depth equal to or greater than about 1 micron and equal to or less than about 1000 microns. The article is suitable for metallurgical bonding at the faying surface.

Spike-Based Feature Extraction For Noise Robust Speech Recognition Using Phase Synchrony Coding, Ismail Uysal, Harsha Sathyendra, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We propose a noise robust feature extraction technique for speech signals using phase synchrony. The front-end employs a psychoacoustic cochlea model with inner hair cells to transform speech into a parallel stream of spike trains as observed in the auditory nerve fibers. The degree of phase synchrony among nerve fibers with similar characteristic frequencies is calculated to yield a feature vector which shows little degradation in response to increasing levels of noise. As a benchmark, the feature set is used in a biologically plausible model with a spike-based, liquid state machine classifier for a simple acoustic classification task. Though applied …

Florida Wireless Implantable Recording Electrodes (Fwire) For Brain Machine Interfaces, Rizwan Bashirullah, John G. Harris, Justin C. Sanchez, Toshikazu Nishida, Jose C. Principe

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reviews on-going efforts towards the development of the Florida Wireless Implantable Recording Electrodes (FWIRE). The FWIRE microsystem platform is a fully implantable flexible substrate microelectrode array that employs state-of-the-art integrate-and-fire (IF) signal representation and wireless interface circuitry for recording neural activity from behaving rodents. The modular nature of the implantable neural recording electrode allows future enhancements to be seamlessly added to improve functionality including but not limited to rechargeability through inductive coupling, custom microelectrode arrays, higher capacity batteries, and more advanced integrated circuit technologies. This paper concentrates on custom integrated circuits such as neural interfacing amplifiers, baseband signal …

A Pitch Estimation Algorithm Based On The Smooth Harmonic Average Peak-To-Valley Envelope, Arturo Camacho, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We propose SHAPE, a novel pitch estimation algorithm (PEA) that builds upon previous PEAs, addressing and solving some of their limitations. The SHAPE algorithm estimates the pitch using a smooth function to compute the average peak to valley distance at harmonic locations. This is done by performing an integral transform over the square-root magnitude of the spectrum using a truncated decaying cosine as a kernel. SHAPE was designed to both match human perception particularly for inharmonic sounds and to be competitive with numerous other PEAs as demonstrated on a common database. © 2007 IEEE.

High-Speed Low-Voltage Cmos Flash Analog-To-Digital Converter For Wideband Communication System-On-A-Chip, Mingzhen Wang

Browse all Theses and Dissertations

With higher-level integration driven by increasingly complex digital systems and downscaling CMOS processes available, system-on-a-chip (SoC) is an emerging technology of low power, high cost effectiveness and high reliability and is exceedingly attractive for applications in high-speed data conversion wireless and wideband communication systems. This research presents a novel ADC comparator design methodology; the speed and performance of which is not restricted by the supply voltage reduction and device linearity deterioration in scaling-down CMOS processes. By developing a dynamic offset suppression technique and a circuit optimization method, the comparator can achieve a 3 dB frequency of 2 GHz in 130 …

On-Chip Signal Generation And Response Waveform Extraction For Analog Built-In-Self-Test, Brian Poling

Browse all Theses and Dissertations

Built-In Self-Test (BIST) is a method of designing and creating an electronic chip or an electronic system that can self test for correct functionality and ensure no manufacturing defects. The reason for analog BIST is the testing of analog parts of analog and mixed-signal ICs is a costly process that traditionally requires the use of expensive high-end automatic test equipment. Due to the nature of the testing and length of the testing process, an efficient analog BIST scheme is in high demand for the ever increasing complexity of analog and mixed-signal circuits. This thesis presents a BIST scheme for generation …

Modeling And Simulation Of A Microturbine Generator To Be Coupled With A Molten Carbonate Fuel Cell For Distributed Generation, Karleine M. Justice

Browse all Theses and Dissertations

Distributed generation is desired when the individual energy requirements ranging from 25-75 kW of office buildings, restaurants, hospitals and apartments can not be met by the current electric utility grid. Microturbine generators as stand alone power generation systems have been designed to meet these requirements. For power requirements up to 50 MW, hybrid fuel cell systems offer higher efficiency and lower levels of pollutant emissions with more advanced fuel energy savings than non-hybrid systems. The objective of this project is to develop a simulation of a microturbine generator as a stand alone power generation system to validate a microturbine generator …

2007 Enacted Wheel Tax Rates (Lohut), Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This publication is a compilation of wheel tax rates using data provided by the Indiana Bureau of Motor Vehicles.

Experimental And Computational Studies Of Temperature Gradient Driven Molecular Transport In Gas Flows Through Nano/Micro-Scale Channels, Yen-Lin Han, Alina A. Alexeenko, Marcus Young, Eric Phillip Muntz

School of Aeronautics and Astronautics Faculty Publications

Studies at the University of Southern California have shown that an unconventional solid-state device, the Knudsen Compressor, can be operated as a micro-scale pump or compressor. The critical components of Knudsen Compressors are gas transport membranes, which can be formed from porous materials or densely packed parallel arrays of channels. An applied temperature gradient across a transport membrane creates a thermal creep pumping action. Experimental and computational techniques that have been developed for the investigations will be discussed. Experimental studies of membranes formed from machined aerogels, activated by radiant heating, have been used to investigate thermal creep flows. In computational …

Automated Composite Column Wrapping, Purdue Ect Team

ECT Fact Sheets Archive

The Automated Composite Column Wrapping is performed by a patented machine known as Robo-Wrapper. Currently there are three versions of the machine available for bridge retrofit work depending on the size of the columns being wrapped. Composite column retrofit jacket systems can be structurally just as effective as conventional steel jacketing in improving the seismic response characteristics of substandard reinforced concrete columns.

New Structural Material - Fiber Reinforced Plastics, Purdue Ect Team

ECT Fact Sheets Archive

Traditional structural materials are heavy and require a great deal of maintenance. If a new breed of structural material could be produced that was lighter, stronger and more resistant to corrosion, impacts, parasites and chemicals, it could be a good substitute for steel, concrete, masonry and wood. One new material that has the potential to meet these demands is starting to show up on the construction industry market, it is Fiber Reinforced Plastics (FRP). Some technologies that have been developed using FRP materials within the last few years are: structural shapes, concrete reinforcing, prestressing and post-tensioning tendons and pre-engineered structural …

Post-Tensioned Steel Structure, Purdue Ect Team

ECT Fact Sheets Archive

Welded steel Moment-Resisting Frames (MRFs) were long considered as one the most earthquake-resistant types of structures. Recently, the idea of applying the post-tensioning technology to achieve moment resistant structural systems has been investigated at the University of California, San Diego. Since 1996, moment-resisting connections using post-tensioning concepts have been developed and tested for precast concrete beam-to-column connections, and concrete shear walls.

Precast Hybrid Moment Resistant Frames, Purdue Ect Team

ECT Fact Sheets Archive

The recent disasters from earthquakes in Northridge, California and Kobe, Japan, demands a structural design that will provide integrity of the structure and protection of the investment against seismic activity. Charles Pankow builders developed a new frame that absorbs seismic energy independent of the integrity of the structural members and that delivers superior post elastic response. The Precast Hybrid Moment Resisting Frame (PHMRF) involves a column/beam connection utilizing both elastic and inelastic action at the joint for Precast Moment Resistant Frames.

Spraywall, Cured-In-Placed Method For Manhole Rehabilitation, Purdue Ect Team

ECT Fact Sheets Archive

Manholes and other underground structures commonly account for 25-30 % of infiltration and up to 70% of inflow in sanitary sewer collection systems. These will cause sewer overflow and endanger the nearby environment. SprayWall is a spray-applied, cured-in-place method of construction and is primarily used in manholes. It uses urethane material that provides excellent corrosion resistance. SprayWall is structural and can withstand ground water loads on a long-term basis.

Welding Clamps, Purdue Ect Team

ECT Fact Sheets Archive

While welding technology has advanced in recent years, methods of fitting pipe remained primitive. Chain Clamps are versatile: each clamp can fit-up elbows, tees, flanges, and other pipe fittings. All carbon steel Chain Clamps are zinc plated to resist spatter and corrosion. On the average, one Chain Clamp costs about 40% less and weighs about 77% less than the required number of cage clamps to cover the same range of pipe diameter.

Decision Aid For Electronic Simulation In Construction, Purdue Ect Team

ECT Fact Sheets Archive

The Decision Aid for Electronic Simulation in Construction is an output of the research “Electronic Simulation in Construction” sponsored by CII (Construction Industry Institute). The Web-based Decision Aid was developed to assist a decision-maker in utilizing the results of this research. This system along with the database allows the user to (i) establish the need for electronic simulation, (ii) ascertain specific needs with respect to application domain, product features, and operating system requirements, and (iii) identify products and suppliers that support the need and requirements established in the previous steps.