Engineering Commons^™

Estimation Of Earthquake Loss Due To Bridge Damage In The St. Louis Metropolitan Area. Ii: Indirect Losses, David Lee Enke, Chakkaphan Tirasirichai, Ronaldo Luna

Engineering Management and Systems Engineering Faculty Research & Creative Works

An approach to estimate the indirect economic loss due to damaged bridges within the highway system from an earthquake event is presented. The indirect cost considered refers to the increased highway transportation cost only. The study zone covers the St. Louis metropolitan area and its surrounding suburban regions. An earthquake scenario centered in St. Louis, with a magnitude 7.0 is used. The direct earthquake loss was primarily damage to bridges, which causes an increase in travel time and distance within the transportation network. This information is then used as input for the indirect loss model. The indirect loss is examined …

Phantom For Evaluating Accuracy Of Image Registration Software, B. Y. Choe, H. S. Jin, R. H. Juh, Hyoung-Koo Lee, J. Y. Song, T. S. Suh

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Provided is a phantom for evaluating the accuracy of image registration software based on a result of matching tomograms of a predetermined position of the phantom, taken using two or more imaging apparatuses. Accordingly, it is possible to more efficiently evaluate the accuracy of the image registration software by comparing the tomograms with one another using a three-dimensional analysis. In addition, it is possible to facilitate the comparison of the tomograms with one another by installing a plurality of indicating bars in the phantom so that their cross sections can appear on each of the tomograms.

Fit Numerical Modeling For Emi Discovery And "Design", James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Exploring Stochastic Characteristics Of Freeway Traffic Breakdown And Recovery Conditions, Chaitanya Mamidala

LSU Master's Theses

In recent times, the term ‘congestion’ has gained a lot of attention due to its negative impact on the mobility and efficiency of transportation network. Congestion control and mitigation of its effects has become a prime concern to many transportation agencies. With breakthroughs in transportation technologies, effective management and utilization of existing infrastructure capacities has been possible. One of the key functions of technological advancements is the ability to understand the different characteristics of traffic that prevail on major freeways and arterials, and to model short-term predictions of traffic conditions with reasonable accuracy. Providing accurate, real-time information makes travelers aware …

Parametric Study Of A Pulsed Vertical Jet In Cross-Flow, Guillaume Francois Bidan

LSU Master's Theses

The potential of pulsed vertical jet in cross-flow for film cooling purposes was experimentally studied and is discussed in this Thesis. A single vertical jet placed in laminar cross-flow conditions was first characterized in steady state at relatively low blowing ratios ranging from 0.150 to 0.600, using Mie scattering visualization methods and hot-wire measurements. Wavelet spectral analysis and image quantification algorithms were applied to the velocity records and averaged visualizations to obtain quantitative data on the jet characteristic frequencies, penetration and coverage. Two different regimes characterized by different structures are identified and adapted scaling variables are provided. Trends in the …

New Method For Approximating Vague Sets To Fuzzy Sets Based On Voting Model, Jian Liu, Zhizhan Liu, Shunxiang Wu, Yongjian Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

By analyzing Vague Sets voting model, we bring forth a new method for approximating Vague Sets to Fuzzy Sets, and its general process is presented in the article. In a voting model, firstly, we suppose that the abstainers must vote for once more, and the results are close studied. Then the randomicity, uncertainty, and conformity of voting are found. As we know, an abstainer may favor somebody, oppose somebody, or just abstain. In this article, we suppose the distribution of results is consistent with a normal distribution. So, we advance the new approximation method based on Gauss Distribution. © 2008 …

Evolutionary Methodology For Optimization Of Image Transforms Subject To Quantization Noise, Michael Ray Peterson

Browse all Theses and Dissertations

Lossy image compression algorithms sacrifice perfect imagereconstruction in favor of decreased storage requirements. Modelossy compression schemes, such as JPEG2000, rely upon the discrete wavelet transform (DWT) to achieve high levels of compression while minimizing the loss of information for image reconstruction. Some compression applications require higher levels of compression than those achieved through application of the DWT and entropy coding. In such lossy systems, quantization provides high compression rates at the cost of increased distortion. Unfortunately, as the amount of quantization increases, the performance of the DWT for accurate image reconstruction deteriorates. Previous research demonstrates that a genetic algorithm can …

Mechanisms Of Nickel-Based Coatings For Fretting Wear Mitigation Of Ti6al4v Interfaces, Carl H. Hager Jr.

Browse all Theses and Dissertations

Fretting wear is an accumulation of damage that occurs at component interfaces that are subjected to high contact stresses coupled with low amplitude oscillation. The key to fretting wear reduction in metallic contacts is the mitigation of galling at the interface, followed by the control of debris production and the rheology of active wear debris. Once the thin surface species of the metallic interfaces is dispersed, adhesion between the contacting nascent surfaces causes the inception of severe surface deformation and material transfer or removal. This is extremely apparent in the fretting wear of aerospace materials such as titanium alloy and …

Novel Redox And Dna-Dependent Conformational Changes In Human Ku, A Dna-Double Strand Break Repair Protein, Jason Alexander Lehman

Browse all Theses and Dissertations

Ionizing radiation (IR) and radiomimetic drugs used in cancer chemotherapy cause DNA double-strand breaks which are repaired by the nonhomologous end joining (NHEJ) pathway. Ku is a heterodimeric protein comprised of 70 and 80 kDa subunits and recognizes free DNA ends. Once Ku is bound to DNA, it binds to the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and forms a heterotrimeric DNA-PK complex for repair and damage signaling.

We have analyzed the Ku protein using multiple biochemical techniques and uncovered a novel reversible redox change (Andrews, Lehman and Turchi, (2006) JBC 281(19):13596-603). From this data, we hypothesized that a redox-dependent …

Costas Pll Loop System For Bpsk Detection, Rajesh Kumar Keregudadhahalli

Browse all Theses and Dissertations

A 2GHz carrier recovery Costas Loop based BPSK detector is designed using CMOS 0.18μm technology. The designed BPSK detector consists of single to differential conversion circuit, phase/frequency detector, Voltage Controlled Oscillator, differential to single conversion circuit, first order loop filter and a third multiplier. Different architectures available for each block have been discussed along with the design methodology adopted. The schematics were simulated in analog design environment.

The Costas loop presented in this work can sense both 0° and 180° phases at its input. Thus the Costas loop carrier recovery circuit overcomes the 180° phase ambiguity presented by the conventional …

Ici Reduction Methods For Mc-Cdma Systems, Meng Wu

Browse all Theses and Dissertations

Multi-carrier code-division multiple-access (MC-CDMA) is an important multiple access candidate for 4G wireless communication system. While MC-CDMA provides high performance and high capacity in frequency selective fading channels, it is very sensitive to the signal distortion, especially the Inter Carrier Interference (ICI). We apply self-cancelation and a frequency transmission paradigm to MC-CDMA system to improve the sytem performance in an ICI rich environment. Furthermore, we combine the frequency transmission paradigm FD-MC-CDMA with ICI cancelation. Also, we apply all these three schemes into non-contiguous OFDM and non-contiguous MC-CDMA systems in simple Cognitive Radio communication environments and present the simulation results. Theoretical …

Automotive Battery State-Of-Health Monitoring Methods, Ryan J. Grube

Browse all Theses and Dissertations

Effective vehicular power management requires accurate knowledge of battery state, including state-of-charge (SOC) and state-of-health (SOH). An essential functionality of automotive batteries is delivering high power in short periods to crank the engine. A well-known approach to battery SOH monitoring is to infer battery state-of-health from battery impedance or resistance, which is not robust to variation of battery types. The research and development of more reliable battery state-of-health monitoring methods to ensure vehicle start-up ability are presented in this thesis. The methods include a battery cranking voltage based method, a parity-relation based method using battery voltage and cranking current signals, …

Performance Analysis Of Quantitative Bone Measurement With Spiral, Multi-Detector Ct Scanners, Shruti Gupta

Browse all Theses and Dissertations

The measure of bone strength and fracture risk assessment is based primarily on bone mineral density (BMD). Computed tomography (CT), a frequently used radiographic technique that provides cross-sectional images, can be used for BMD quantification. Called quantitative computed tomography (QCT), it determines true volumetric density and also differentiates between trabecular and cortical bone. As a result, QCT improves the ability to detect early changes in trabecular BMD accurately and precisely.

The introduction of helical CT for quantitative analysis introduces new complexities. Even though using multi-detector helical CT for BMD assessment is being suggested, a detailed analysis of its validity is …

Bridge Maintenance Survey For Indiana Counties, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The objective of this report is to summarize the current bridge maintenance practices of the different counties within Indiana. This information is intended to help others understand which maintenance practices seem to be working and what does not seem to work. Further, this report will be used to assess the need for specialized training and information courses to be offered through the Indiana LT AP office.

Of the all of the Indiana counties surveyed, a total of 50 responses were received. The data contained within this report is based upon the number of responses received.

The basic findings of this …

High-Order Discontinuous Galerkin Method For Boltzmann Model Equations, Alina A. Alexeenko, Cyril Galitzine, Alexander M. Alekseenko

School of Aeronautics and Astronautics Faculty Publications

High-order Runge-Kutta discontinuous Galerkin (DG) method is applied to the kinetic model equations describing rarefied gas flows. A conservative DG discretization of nonlinear collision relaxation term is formulated for Bhatnagar-Gross-Krook and ellipsoidal statistical models. The numerical solutions using RKDG method of order up to four are obtained for two flow problems: the heat transfer between parallel plates and the normal shock wave. The convergence of RKDG method is compared with the conventional secondorder finite volume method for the heat transfer problem. The normal shock wave solutions obtained using RKDG are compared with the experimental measurements of density and velocity distribution …

Rfccd Microthruster Performance Via Numerical Simulation, William B. Stein, Alina A. Alexeenko, Ivana Hrbud

School of Aeronautics and Astronautics Faculty Publications

Particle-in-cell/Monte Carlo (PIC/MCC) and Direct Simulation Monte Carlo (DSMC) algorithms comprise a numerical model to assess the propulsive capability of a RF plasma microthruster concept. This thruster concept is an electrothermal device and exploits RF capacitively coupled discharge (RFCCD) to heat a propellant. This RF plasma microthruster has potential to alleviate some severe constraints on microsatellite propulsion systems such as power, mass, volume and lifetime. The discharge characteristics are investigated by permuting electrode geometry (0.5 - 10 mm) and applied voltage (10 - 500 V) at a constant RF frequency of 200 MHz and a pressure of 3 Torr. PIC/MCC …

Nesting Forward-Mode Ad In A Functional Framework, Jeffrey M. Siskind, Barak A. Pearlmutter

Department of Electrical and Computer Engineering Technical Reports

We discuss the augmentation of a functional-programming language with a derivative- taking operator implemented with forward-mode automatic differentiation (AD). The primary technical difficulty in doing so lies in ensuring correctness in the face of nested invocation of that operator, due to the need to distinguish perturbations introduced by distinct invocations. We exhibit a series of implementations of a referentially- transparent forward-mode-AD derivative-taking operator, each of which uses a different non-referentially-transparent mechanism to distinguish perturbations. Even though the forward-mode-AD derivative-taking operator is itself referentially transparent, we hypothesize that one cannot correctly formulate this operator as a function definition in current pure …

An Efficient Network Model For Determining The Effective Thermal Conductivity Of Particulate Thermal Interface Materials, S Kanuparthi, G Subbarayan, Thomas Siegmund, B Sammakia

School of Mechanical Engineering Faculty Publications

Particulate composites are commonly used in Microelectronics applications. One example of such materials is Thermal Interface Materials (TIMs) that are used to reduce the contact resistance between the chip and the heat sink. The existing analytical descriptions of thermal transport in particulate systems do not accurately account for the effect of inter-particle interactions, especially in the intermediate volume fractions of 30-80%. Another crucial drawback in the existing analytical as well as the network models is the inability to model size distributions (typically bimodal) of the filler material particles that are obtained as a result of the material manufacturing process. While …

"... A Good Imagination And A Pile Of Junk.", Shawn Jordan, Robin S. Adams

School of Engineering Education Graduate Student Series

The engineering workplace is placing more emphasis on teamwork in interdisciplinary environments, out-of-the-box thinking, creative engineering, and brainstorming. These skills are taught to varying degrees in standard engineering curriculums, and often the most fruitful opportunities exist for students to learn in venues outside of the classroom.

This paper will show how building Rube Goldberg machines is a fantastic way for learners from various disciplines to get hands-on project experience in a team environment. Intense brainstorming and work sessions result in inventive and unique machines that are fascinating for both participants and spectators to watch. In addition, students have opportunities to …

Quantum Dots: Bringing Nanoscience And Engineering Into The High School Classroom, Shanna R Daly, Lynn Bryan, Emily D Wischow

School of Engineering Education Graduate Student Series

No abstract provided.

Artificial Intelligence Methods To Forecast Engineering Students' Retention Based On Cognitive And Non Cognitive Factors, Jien-Jou Lin, Alexander Malyscheff, P.K. Imbrie

School of Engineering Education Graduate Student Series

No abstract provided.

Application Of The Dsmc Method For Design Of A Coaxial Microthruster Nozzle, William B. Stein, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

The Direct Simulation Monte Carlo (DSMC) method is used to numerically simulate and design a micronozzle with improved performance. Thrust calculations using the DSMC method demonstrate that the coaxial micronozzles can achieve milli-Newton thrust levels with specific impulses on the order of 45 s using argon in a cold gas expansion. Improved micronozzle designs of coaxial microthrusters are also proposed. Coaxial micronozzles utilizing center-body geometries to exploit pressure thrust show about 140% increase in specific impulse at low Reynolds numbers compared to a traditional converging nozzle.

Hollo-Bolt®: Blind Connector For Structural Steelwork, Purdue Ect Team

ECT Fact Sheets Archive

Structural steel connections for connecting to square, rectangular or circular structural tube or to conventional steel where access is available from one side only poses problems. A technology was needed which could provide a quicker and tidier installation than traditional methods such as welding, unsightly strapping or drilling and tapping holes. The invention of the Hollo-Bolt® provided such a solution.

Smartball™: Free Swimming Leak Detection System, Purdue Ect Team

ECT Fact Sheets Archive

Leak detection systems measure ultrasonic noise, infrared temperature variances or electrical flux to detect leakage in structures like, pipes, tanks, geo-membrane retaining structures etc. SmartBall® is a free flowing leak detection system developed by Pure Technologies. It consists of a foam ball that has a smaller aluminum ball at its core. This aluminum core houses an ultrasonic device that sends ultrasonic signals and also collects the reflected sound waves.

Gas-Phonon Interaction Model For Subcontinuum Thermal Transport Simulations, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Subcontinuum thermal transport problems such as the contact thermal resistance of semiconductor-gas interactions may play an important role in micro/nano-scale devices. In present work, a gas-phonon interaction modeling approach is suggested based on Boltzmann transport equations. Verification has been conducted by comparisons with asymptotic analytical solutions as well as previously reported numerical results and experimental data. Thermal transpiration in nano-sized channels and thermal resistance of nano-sized constrictions has been studied using the current model Thermal transpiration is the main mechanism for temperature driven pumps in nano/micro-devices. In order to maintain higher temperature ratio between the two ends of the gas …

Determination Of Superior Surface Strains And Stresses, And Vocal Fold Contact Pressure In A Synthetic Larynx Model Using Digital Image Correlation, Mychal Spencer, Thomas Siegmund, Luc Mongeau

School of Mechanical Engineering Faculty Publications

No abstract provided.

Modeling Of Spin Metal-Oxide-Semiconductor Field-Effect Transistor: A Nonequilibrium Green’S Function Approach With Spin Relaxation, Tony Low, Mark S. Lundstrom, Dmitri E. Nikonov

Department of Electrical and Computer Engineering Faculty Publications

A spin metal-oxide-semiconductor field-effect transistor spin MOFSET, which combines a Schottky-barrier MOFSET with ferromagnetic source and drain contacts, is a promising device for spintronic logic. Previous simulation studies predict that this device should display a very high magnetoresistance MR ratio between the cases of parallel and anitparallel magnetizations for the case of half-metal ferromagnets HMF. We use the nonequilibrium Green’s function formalism to describe tunneling and carrier transport in this device and to incorporate spin relaxation at the HMF-semiconductor interfaces. Spin relaxation at interfaces results in nonideal spin injection. Minority spin currents arise and dominate the leakage current for antparallel …

Influence Of Phonon Scattering On The Performance Of P-I-Np-I-N Band-To-Band Tunneling Transistors, Siyuranga O. Koswatta, Mark S. Lundstrom, Dmitri E. Nikonov

Department of Electrical and Computer Engineering Faculty Publications

Power dissipation has become a major obstacle in performance scaling of modern integrated circuits and has spurred the search for devices operating at lower voltage swing. In this letter, we study p-i-n band-to-band tunneling field effect transistors taking semiconducting carbon nanotubes as the channel material. The on current of these devices is mainly limited by the tunneling barrier properties, and phonon-scattering has only a moderate effect.We show, however, that the off current is limited by phonon absorption assisted tunneling, and thus is strongly temperature dependent. Subthreshold swings below the 60 mV/decade conventional limit can be readily achieved even at room …

Inversion Capacitance-Voltage Studies On Gaas Metal-Oxide-Semiconductor Structure Using Transparent Conducting Oxide As Metal Gate, T. Yang, Y. Liu, P. D. Ye, Y. Xuan, H. Pal, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

A systematic capacitance-voltage C-V study has been performed on GaAs metaloxide- semiconductor MOS structures with atomic-layer-deposited Al2O3 as gate dielectrics and indium tin oxide ITO as the metal gate. The transparent conducting ITO gate allows homogeneous photoillumination on the whole MOS capacitance area, such that one can easily observe the low-frequency LF C-V and quasistatic C-V of GaAs at room temperature. The semiconductor capacitance effect on GaAs MOS devices has also been identified and insightfully discussed based on the obtained LF C-V curves. The semiconductor capacitance effect becomes more important for devices with high-mobility channel materials and aggressively scaled high-k …

A New Paradigm For Human Resuscitation Research Using Intelligent Devices, Charles F. Babbs, Andre E. Kemeny, Weilun Quan, Gary Freeman

Weldon School of Biomedical Engineering Faculty Publications

Objectives: To develop new methods for studying correlations between the performance and outcome of resuscitation efforts in real-world clinical settings using data recorded by automatic devices such as automatic external defibrillators (AEDs), and to explore effects of shock timing and chest compression depth in the field. Methods: In 695 records of AED use in the pre-hospital setting, continuous compression data were recorded using AEDs capable of measuring sternal motion during compressions, together with timing of delivered shocks and the electrocardiogram. In patients who received at least one shock, putative return of spontaneous circulation (P-ROSC) was defined as a regular, narrow …