Engineering Commons^™

Optimal Tracking Control Of Affine Nonlinear Discrete-Time Systems With Unknown Internal Dynamics, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, direct dynamic programming techniques are utilized to solve the Hamilton Jacobi-Bellman equation forward-in-time for the optimal tracking control of general affine nonlinear discrete-time systems using online approximators (OLA's). the proposed approach, referred as adaptive dynamic programming (ADP), is utilized to solve the infinite horizon optimal tracking control of affine nonlinear discrete-time systems in the presence of unknown internal dynamics and a known control coefficient matrix. the design is implemented using OLA's to realize the optimal feedback control signal and the associated cost function. the feedforward portion of the control input is derived and approximated using an additional …

Multiple Pulsejet Boring Device, W. A. Berger, J. A. Carter, Marian Mazurkiewicz, R. M. Pell, R. A. Spalletta

Mining Engineering Faculty Research & Creative Works

A method and device for boring a hole [5] through a material along a desired path includes an umbilical subsystem [2000] connected to a boring subsystem [3000] having a plurality of pulsejets [3100]. These pulsejets [3100] repeatedly receive and ignite a combustible fluid [7] in a combustion chamber [3230] causing a portion of the fluid [7] to be forced out of a nozzle [3260] at high speeds as a fluid slug [10] that impacts materials ahead of the pulsejet [3100]. A controller [3310] controls the amount of fluid provided to each pulsejet [3100], and the firing timing, thereby controlling the …

Antibacterial Properties Of A Tri-Sodium Citrate Modified Glass Polyalkenoate Cement, A. W. Wren, D. Boyd, R. Thornton, J. C. Cooney, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Primary deep infection following joint replacement surgery accounts for 7% of all revisions. Glass polyalkenoate cements (GPCs) have previously been shown to exhibit antibacterial properties. The present study had two objectives. The first was to determine if addition of tri-sodium citrate (TSC) to the powder phase of an Al-free GPC (0.04 SrO-0.12 CaO-0.36 ZnO-0.48 SiO2, by mole fraction) enhanced the resultant cement's antibacterial properties against three strains of bacteria that are commonly found in periprosthetic sites following total joint replacements (TJRs); namely, E. coli, B. fragilis, and S. epidermidis. Four cement sets were prepared, which contained 0 wt% TSC (control), …

The Design By Molecular Dynamics Modeling And Simulations Of Porous Polymer Adsorbent Media Immobilized On The Throughpore Surfaces Of Polymeric Monoliths, E. Riccardi, J. C. Wang, A. I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ion-exchange porous adsorbent media having intermediate and low surface densities of dextran polymer grafted on the surface of the through pores of polymeric monoliths are constructed and characterized by a molecular dynamic modeling and simulation approach that has also been shown to be effective in the construction and characterization of porous ion-exchange adsorbent media whose number of immobilized dextran polymer chains per unit surface area is high. the activation step that prepares the surface of the pores of the dextran polymer layer for the immobilization of the charged ligands insignificantly affected the pore structure of the dextran polymer layer, while …

Cavities' Identification Algorithm For Power Integrity Analysis Of Complex Boards, S. Cicerone, Antonio Orlandi, Bruce Archambeault, Samuel R. Connor, Jun Fan, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

The analysis and the design of the Power Delivery Network (PDN) is crucial in the real world of high-speed and high-performance on-board systems. In this context, the Cavity Model (where facing portions of power bus are considered electromagnetic resonant cavities) can be used to study the generation and propagation of noise. Given a real-world board's layout, one of the primary requirements for the application of this technique is the geometrical identification of all the cavities and their connectivity. This paper is focused on the fully automatic generation of this geometrical dataset as part of an integrated tool for the analysis …

Monoclinic Optical Constants, Birefringence, And Dichroism Of Slanted Titanium Nanocolumns Determined By Generalized Ellipsometry, Daniel Schmidt, Benjamin Booso, Tino Hofmann, Eva Schubert, Andrew Sarangan, Mathias Schubert

Electrical and Computer Engineering Faculty Publications

Generalized spectroscopic ellipsometry determines the principal monoclinic optical constants of thin films consisting of slanted titanium nanocolumns deposited by glancing angle deposition under 85° incidence and tilted from the surface normal by 47°. Form birefringence measured for wavelengths from 500 to 1000 nm renders the Ti nanocolumns monoclinic absorbing crystals with c-axis along the nanocolumns, b-axis parallel to the film interface, and 67.5° monoclinic angle between the aand c-axes. The columnar thin film reveals anomalous optical dispersion, extreme birefringence, strong dichroism, and differs completely from bulk titanium. Characteristic bulk interband transitions are absent in the spectral range investigated.

Generating Multi-Sensor Precipitation Estimates Over Radar Gap Areas, Shayesteh E. Mahani, Reza Khanbilvardi

Publications and Research

Generating a multi-sensor precipitation product over radar gap area is the objective of the present study. A merging approach is developed to improve Satellite-based Precipitation Estimates (SPE) by merging with ground-based Radar Rainfall (RR) estimates because remote satellites are the only source that can collect information from areas where are inaccessible by ground-based radar and/or rain gauge networks. The merging algorithm is capable of extending radar information from pixels with available RR to their neighboring pixels with no radar information by merging RR with SPE, which is, usually, available for all pixels. SPE is combined with RR using the weighting-based …

Rapidly Solidified Sm–Co–V Nanocomposite Permanent Magnets, R. S. K. Valiveti, A. Ingmire, Jeffrey E. Shield

Nebraska Center for Materials and Nanoscience: Faculty Publications

Alloys around the Sm–Co eutectic composition provide an opportunity to form two-phase nanocomposite permanent magnets consisting of nanoscale Co fibers embedded in Sm₂Co₁₇.While ternary alloying elements may refine the scale of the structure, they may also disrupt the eutectic growth and lead to the formation of primary Co. Thus, microstructural selection maps were constructed for conventionally solidified Sm–Co–V alloys. It was found that V additions enlarged the primary Sm₂Co₁₇-forming region and, at (Sm_0.09Co_0.91)₉₇ V₃, resulted in a eutectic structure. Upon rapid solidification, this alloy was …

Free Electron Behavior In Inn: On The Role Of Dislocations And Surface Electron Accumulation, V. Darakchieva, Tino Hofmann, Mathias Schubert, B. E. Sernelius, B. Monemar, P. O. A. Persson, F. Giuliani, E. Alves, H. Lu, W. J. Schaff

Nebraska Center for Materials and Nanoscience: Faculty Publications

The free electron behavior in InN is studied on the basis of decoupled bulk and surface accumulation electron densities in InN films measured by contactless optical Hall effect. It is shown that the variation in the bulk electron density with film thickness does not follow the models of free electrons generated by dislocation-associated nitrogen vacancies. This finding, further supported by transmission electron microscopy results, indicates the existence of a different thickness-dependent doping mechanism. Furthermore, we observe a noticeable dependence of the surface electron density on the bulk density, which can be exploited for tuning the surface charge in future InN …

Hole Diffusion Profile In A P-P+ Silicon Homojunction Determined By Terahertz And Midinfrared Spectroscopic Ellipsometry, Tino Hofmann, C. M. Herzinger, T. E. Tiwald, John A. Woollam, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

The noncontact and nondestructive optical determination of spatial distributions of free-charge-carriers in low-doped semiconductor homo- and heterojunctions addresses fundamental physical properties of device related structures. For low-density free-charge-carriers, particularly for hole densities with their intrinsically lower mobility parameters than electron densities, optical characterization is a challenge. The carrier density plasma frequencies are located at long wavelength equivalents within the terahertz spectral region.

Resistive Hysteresis And Interface Charge Coupling In Batio3-Zno Heterostructures, V. M. Voora, Tino Hofmann, M. Brandt, M. Lorenz, M. Grundmann, N. Ashkenov, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

We report on temperature, time, and voltage dependent resistive hysteresis measurements of BaTiO₃-ZnO heterostructures grown on (001) Si substrates by pulsed laser deposition. We observe a diodelike behavior and cycling-voltage dependent hysteresis formation under forward bias. We explain these effects with depletion layer formation between the ZnO and BaTiO₃ layers, an additional barrier due to the spontaneous polarization of ZnO and the ferroelectric nature of BaTiO₃. The disappearance of the resistive hysteresis above the ferroelectric-paraelectric phase transition temperature of BaTiO₃ conformed that the hysteresis is related to the ferroelectricity of BaTiO₃. Time …

A Self Healing Smart Syntactic Foam Based Grid Stiffened Sandwich Structure, Manu Kuruvila John

LSU Doctoral Dissertations

Syntactic foams are composite materials synthesized by dispersing microballoons in a polymeric, ceramic or metallic matrix. In the past three decades, syntactic foams have gained immense importance as a lightweight and damage-tolerant material when used in foam-cored sandwich structures. Because of the structural-length scale damages by low velocity impact such as tool drops, runway debris etc., sandwich structures usually have a very low residual structural capacity. Unfortunately, macro-length scale damage, in particular internal damage such as impact damage, is very difficult to repair. Therefore, there is a genuine need to develop impact-tolerant and self-healing syntactic foams which can be used …

State Feedback Control With Time Delay, Akshay Nareshraj Singh

LSU Doctoral Dissertations

In this thesis we start with an introduction to the theory of vibration control. We broadly classify the control methods into passive and active schemes. We introduce the problem of state feedback control and provide the classical solution in the form of Ackermann formula. We then identify the limitations of the classical approach and present the more elegant solution of partial pole assignment without spillover. We highlight the problem with model uncertainties and describe the method of pole assignment using data from measured receptances. This approach is extended for pole assignment for a linear vibrating system by using state feedback …

Copula-Based Multivariate Hydrologic Frequency Analysis, Hemant Chowdhary

LSU Doctoral Dissertations

Multivariate frequency distributions are being increasingly recognized for their role in hydrological design and risk management. The conventional multivariate distributions are severely limited in that all constituent marginals have to be from the same distribution family. The copula method is a newly emerging approach for deriving multivariate distributions which overcomes this limitation. Use of copula method in hydrological applications has begun only recently and ascertaining the applicability of different copulas for combinations of various hydrological variables is currently an area of active research. Since there exists a variety of copulas capable of characterizing a broad range of dependence, the selection …

Fault Detection Filter Design For Linear Systems, Xiaobo Li

LSU Doctoral Dissertations

This dissertation considers residual generation for robust fault detection of linear systems with control inputs, unknown disturbances and possible faults. First, multi-objective fault detection problems such as $\mathscr{H_-}/ \mathscr{H_\infty}$, $\mathscr{H}_2/\mathscr{H_\infty}$ and $\mathscr{H_\infty}/\mathscr{H_\infty}$ have been formulated for linear continuous time-varying systems (LCTVS) in time domain for finite horizon and infinite horizon case, respectively. It is shown that under mild assumptions, the optimal solution is an observer determined by solving a standard differential Riccati equation (DRE). The solution is also extended to the case when the initial state for the system is unknown. Second, the parallel problems are also solved for linear …

Modeling The Risk Factors Associated With The Neck Disorders During Manual Material Handling Tasks, Ashish D. Nimbarte

LSU Doctoral Dissertations

Work-related musculoskeletal disorders (MSD) of the neck or cervical spine result in longer sick leaves, substantial levels of human suffering, and high costs for society. Epidemiological studies clearly indicate strong associations between MSD of the neck and the work activities requiring forceful arm exertions and heavy lifting. However, studies evaluating the loading of the cervical spine during forceful arm exertions and heavy lifting tasks are limited. Major neck muscles, the sternocleidomastoid and the upper trapezius, run parallel to the cervical spine and couple the shoulder to the skull. It was hypothesized that such anatomical orientation may require these muscles to …

Quantitative Macro- And Microscale Methods For Characterizing Cell Viability, Julianne Forman Audiffred

LSU Doctoral Dissertations

The goal of this study is to combine molecular and microdevice methods to characterize and quantify viability of single mammalian cells. Fluorescent-based assays were optimized for adherent HeLa and suspension Jurkat cells and were used as a tool for validation of a microfabricated diagnostic device. Cell and substrate/surface interactions were considered for designing a microfluidic device that can be used to characterize cell viability for quantitative biomedical and cell biology applications, which require label-free, real-time monitoring of cells. Several interdisciplinary methods are employed to evaluate electrical impedance differences between live and dead Jurkat cells in a microfluidic device. Biological Micro-Electro-Mechanical …

Three-Dimensional Target Modeling With Synthetic Aperture Radar, John R. Hupton

Master's Theses

Conventional Synthetic Aperture Radar (SAR) offers high-resolution imaging of a target region in the range and cross-range dimensions along the ground plane. Little or no data is available in the range-altitude dimension, however, and target functions and models are limited to two-dimensional images. This thesis first investigates some existing methods for the computation of target reflectivity data in the deficient elevation domain, and a new method is then proposed for three-dimensional (3-D) SAR target feature extraction.

Simulations are implemented to test the decoupled least-squares technique for high-resolution spectral estimation of target reflectivity, and the accuracy of the technique is assessed. …

A New Pulsed Electric Field Therapy For Melanoma Disrupts The Tumor's Blood Supply And Causes Complete Remission Without Recurrence, Richard Nuccitelli, Xinhua Chen, Andrei G. Pakhomov, Wallace H. Baldwin, Saleh Sheikh, Jennifer L. Pomicter, Wei Ren, Chris Osgood, R. James Swanson, Juergen F. Kolb, Stephen J. Beebe, Karl H. Schoenbach

Bioelectrics Publications

We have discovered a new, ultrafast therapy for treating skin cancer that is extremely effective with a total electric field exposure time of only 180 mu sec. The application of 300 high-voltage (40 kV/cm), ultrashort (300 nsec) electrical pulses to murine melanomas in vivo triggers both necrosis and apoptosis, resulting in complete tumor remission within an average of 47 days in the 17 animals treated. None of these melanomas recurred during a 4-month period after the initial melanoma had disappeared. These pulses generate small, long-lasting, rectifying nanopores in the plasma membrane of exposed cells, resulting in increased membrane permeability to …

Computational Model For Predicting Nonlinear Viscoelastic Damage Evolution In Materials Subjected To Dynamic Loading, Flavio V. Souza, Yong-Rak Kim, George A. Gazonas, David H. Allen

Department of Mechanical and Materials Engineering: Faculty Publications

Many inelastic solids accumulate numerous cracks before failure due to impact loading, thus rendering any exact solution of the IBVP untenable. It is therefore useful to construct computational models that can accurately predict the evolution of damage during actual impact/dynamic events in order to develop design tools for assessing performance characteristics. This paper presents a computational model for predicting the evolution of cracking in structures subjected to dynamic loading. Fracture is modeled via a nonlinear viscoelastic cohesive zone model. Two example problems are shown: one for model validation through comparison with a one-dimensional analytical solution for dynamic viscoelastic debonding, and …

Insecurity By Obscurity: A Review Of Soho Router Literature From A Network Security Perspective, Patryk Szewczyk, Craig Valli

Journal of Digital Forensics, Security and Law

Because of prevalent threats to SoHo based ADSL Routers, many more devices are compromised. Whilst an end-user may be at fault for not applying the appropriate security mechanisms to counter these threats, vendors should equally share the blame. This paper reveals that the lack of security related content and poor overall design could impact on end-users’ interpretation and willingness to implement security controls on their ADSL router. It argues that whilst the number of threats circulating the Internet is increasing, vendors are not improving their product literature.

Design, Implementation And Validation Of An Attitude Determination Subsystem For Nanosatellites, Mathieu Naslin

Master's Theses - Daytona Beach

The purpose of this study is to design and analyze the accuracy of an attitude determination subsystem for a satellite of the CubeSat class by using low cost sensors. CubeSats are nanosatellites that complies a certain amount of layout criterions described by the California Polytechnic State University. A 3-axis attitude determination platform has been designed with emphasis on the use of low cost, off the shelf sensors. This platform features a sun sensor, a magnetometer and an earth sensor. The principles of observation and the description of the acquisition method are explained. The interfacing of the software package and real …

Lectures In Elementary Fluid Dynamics: Physics, Mathematics And Applications, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Chapter 1:

It takes little more than a brief look around for us to recognize that fluid dynamics is one of the most important of all areas of physics—life as we know it would not exist without fluids, and without the behavior that fluids exhibit.

It is the goal of these lecture notes to help students in this process of gaining an understanding of, and an appreciation for, fluid motion—what can be done with it, what it might do to you, how to analyze and predict it.

Kentucky Water Resources Research Institute Annual Technical Report Fy 2008, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Annual Technical Reports (USGS’s 104b Grant Program)

The 2008 Annual Technical Report for Kentucky consolidates reporting requirements of the Section 104(b) base grant award into a single document that includes: 1) a synopsis of each research project conducted with grant funds during the period, 2) citations for related publications, reports, and presentations, 3) a description of information transfer activities, 4) a summary of student support during the reporting period, and 5) notable awards and achievements during the year.

How Driver Risk Perception Affects Operating Speeds, Nikiforos Stamatiadis, Ted H. Grossardt, Keiron Bailey

Kentucky Transportation Center Faculty and Researcher Publications

Excessive speed is one of the primary safety hazards facing highway users. However, in many cases operating speeds exceed design speeds, and drivers generally ignore posted speed limits. The main objective of this research was to identify roadway elements and roadside features that could influence driver operating speeds in rural two-lane roads without compromising safety.

Virtual Reality video simulations were employed and drivers recorded the influence of these elements on their judgments about the appropriate driving speed. The driver/participants viewed 22 models projected on a large screen in a darkened room, simulating the windshield of a vehicle.

The viewing sessions …

Diamond And Related Nanomaterials For Mems/Nems Applications, Rakesh K. Joshi, Ashok Kumar

Mechanical Engineering Faculty Publications

No abstract provided.

Spectral And Spatial Analysis Of False Alarms In Airborne Minefield Data, Abhishek Sanaka

Masters Theses

"Tests run in May 2005 at an arid site as part of airborne minefield detection yielded substantial airborne background data with ground truthed and surveyed false alarm locations. ERDC and MultiSensor LLC identified the locations, geo referenced and documented different false alarms. The project reported here built a self-contained database of image chips recording target signatures for MSI (four bands) and MWIR sensors for false alarms from this background data and mines from related areas. The image chips represent various days, times of day, altitudes, as well as several different sources of false alarm and mine types. The database facilitates …

Feasibility Of A Human Performance Model In Consequence Management, Kashmeera Ghosh

Masters Theses

"Human civilization has always encountered unpredictable disasters as a result of natural events. Now it also faces the disasters caused by terrorist attacks. Governments must have consequence management plans in place to protect public health and safety, restore essential services, and provide emergency relief to affected businesses and individuals. Human performance models predict outcomes in complex dynamic situations. Such models can simulate disaster management procedures under varying circumstances. This work applies human performance modeling in a terrorist situation and evaluates possible uses of such models by first responders in practical consequence management applications. It includes a case study of an …

Molecular Dynamics Study Of Thermal Conductivity Enhancement Of Water Based Nanofluids, Parveen Sachdeva

Electronic Theses and Dissertations

A systematic investigation using molecular dynamics (MD) simulation involving particle volume fraction, size, wettability and system temperature is performed and the effect of these parameters on the thermal conductivity of water based nanofluids is discussed. Nanofluids are a colloidal suspension of 10 -100 nm particles in base fluid. In the last decade, significant research has been done in nanofluids, and thermal conductivity increases in double digits were reported in the literature. This anomalous increase in thermal conductivity cannot be explained by classical theories like Maxwell's model and Hamilton-Crosser model for nanoparticle suspensions. Various mechanisms responsible for thermal conductivity enhancement in …

An Integrated Probability-Based Approach For Multiple Response Surface Optimization, Okay Isik

Engineering Management & Systems Engineering Theses & Dissertations

Nearly all real life systems have multiple quality characteristics where individual modeling and optimization approaches can not provide a balanced compromising solution. Since performance, cost, schedule, and consistency remain the basics of any design process, design configurations are expected to meet several conflicting requirements at the same time. Correlation between responses and model parameter uncertainty demands extra scrutiny and prevents practitioners from studying responses in isolation. Like any other multi-objective problem, multi-response optimization problem requires trade-offs and compromises, which in turn makes the available algorithms difficult to generalize for all design problems. Although multiple modeling and optimization approaches have been …